author,date.accessioned,date.available,date.issued,description.department,identifier,identifier.uri,language.iso,relation.ispartof,rights.restriction,subject,title,type,pdf,publisher,abstract,description.sponsorship,description,title.alternative,contributor.utaustinauthor,language,identifier.url
"['Laboratory for Freeform Fabrication', 'University of Texas at Austin']",2018-04-10T15:54:05Z,2018-04-10T15:54:05Z,1990,Mechanical Engineering,doi:10.15781/T20R9MM7Z,http://hdl.handle.net/2152/64232,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Laboratory for Freeform Fabrication', 'Annual International Solid Freeform Fabrication Symposium', 'Table of Contents']",1990 Annual International Solid Freeform Fabrication Symposium Table of Contents,Conference proceedings,https://repositories.lib.utexas.edu//bitstreams/05e27a82-99b2-45d1-a692-a248aeb63942/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T14:39:06Z,2022-08-23T14:39:06Z,1990,Mechanical Engineering,,"['https://hdl.handle.net/2152/115349', 'http://dx.doi.org/10.26153/tsw/42249']",eng,1990 International Solid Freeform Fabrication Symposium,Open,table of contents,1990 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/e75c0431-5a10-4b46-ad84-46a7bfe3f0a2/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T16:54:52Z,2022-08-23T16:54:52Z,1991,Mechanical Engineering,,"['https://hdl.handle.net/2152/115353', 'http://dx.doi.org/10.26153/tsw/42253']",eng,1991 International Solid Freeform Fabrication Symposium,Open,table of contents,1991 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/f3bfeae7-ecdd-4214-9c63-e3dd5cfd2bb2/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T16:56:10Z,2022-08-23T16:56:10Z,1992,Mechanical Engineering,,"['https://hdl.handle.net/2152/115354', 'http://dx.doi.org/10.26153/tsw/42254']",eng,1992 International Solid Freeform Fabrication Symposium,Open,table of contents,1992 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/ca3cc84d-3932-46b6-9bf0-10a43a0215a3/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T16:57:15Z,2022-08-23T16:57:15Z,1993,Mechanical Engineering,,"['https://hdl.handle.net/2152/115355', 'http://dx.doi.org/10.26153/tsw/42255']",eng,1993 International Solid Freeform Fabrication Symposium,Open,table of contents,1993 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/72119455-4ccd-4827-a74d-fba68589ed3a/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T16:58:01Z,2022-08-23T16:58:01Z,1994,Mechanical Engineering,,"['https://hdl.handle.net/2152/115356', 'http://dx.doi.org/10.26153/tsw/42256']",eng,1994 International Solid Freeform Fabrication Symposium,Open,table of contents,1994 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/cf9b9c26-2ab9-4c7a-a3f0-bfe34bb1ad12/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T16:59:05Z,2022-08-23T16:59:05Z,1995,Mechanical Engineering,,"['https://hdl.handle.net/2152/115357', 'http://dx.doi.org/10.26153/tsw/42257']",eng,1995 International Solid Freeform Fabrication Symposium,Open,table of contents,1995 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/4329961e-8534-4687-9f52-8f041bb18f6d/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T16:59:58Z,2022-08-23T16:59:58Z,1996,Mechanical Engineering,,"['https://hdl.handle.net/2152/115358', 'http://dx.doi.org/10.26153/tsw/42258']",eng,1996 International Solid Freeform Fabrication Symposium,Open,table of contents,1996 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/40fc45a9-1b4b-404a-9eff-dd1c6cdcc269/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:00:53Z,2022-08-23T17:00:53Z,1997,Mechanical Engineering,,"['https://hdl.handle.net/2152/115359', 'http://dx.doi.org/10.26153/tsw/42259']",eng,1997 International Solid Freeform Fabrication Symposium,Open,table of contents,1997 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/4eea6bbb-3d12-49bc-a9af-9227042aec85/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:01:47Z,2022-08-23T17:01:47Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/115360', 'http://dx.doi.org/10.26153/tsw/42260']",eng,1998 International Solid Freeform Fabrication Symposium,Open,table of contents,1998 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/6f2913d8-b81a-4a73-a3b2-619f617e5f22/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:02:48Z,2022-08-23T17:02:48Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/115361', 'http://dx.doi.org/10.26153/tsw/42261']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['table of contents', 't']",1999 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/d353e0d0-0aaa-4b00-bc18-7bc86eed3032/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:06:19Z,2022-08-23T17:06:19Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/115362', 'http://dx.doi.org/10.26153/tsw/42262']",eng,2000 International Solid Freeform Fabrication Symposium,Open,table of contents,2000 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/6a3c1a7f-83ca-46af-a660-3528baa2ca87/download,,,,,,,,
International Solid Freeform Fabrication Symposium,2019-06-13T13:56:34Z,2019-06-13T13:56:34Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/74939', 'http://dx.doi.org/10.26153/tsw/2051']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Eleventh Solid Freeform Fabrication (SFF) Symposium,2000 Preface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15e04d72-920f-4dd6-aaae-cdbd9c866e7b/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:07:35Z,2022-08-23T17:07:35Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/115363', 'http://dx.doi.org/10.26153/tsw/42263']",eng,2001 International Solid Freeform Fabrication Symposium,Open,table of contents,2001 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/6f8c99c1-c606-4d3e-9556-e21d2db217d2/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:09:06Z,2022-08-23T17:09:06Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/115364', 'http://dx.doi.org/10.26153/tsw/42264']",eng,2002 International Solid Freeform Fabrication Symposium,Open,table of contents,2002 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/e20ae9f5-d2da-43da-9ea6-ae6c6e966a60/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:10:34Z,2022-08-23T17:10:34Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/115365', 'http://dx.doi.org/10.26153/tsw/42265']",eng,2003 International Solid Freeform Fabrication Symposium,Open,table of contents,2003 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/69407420-e70d-409b-82e3-45cf08f61289/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:11:56Z,2022-08-23T17:11:56Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/115366', 'http://dx.doi.org/10.26153/tsw/42266']",eng,2004 International Solid Freeform Fabrication Symposium,Open,table of contents,2004 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/51061f27-b489-4f7d-a4e1-85ef7ee1b631/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:14:22Z,2022-08-23T17:14:22Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/115367', 'http://dx.doi.org/10.26153/tsw/42267']",eng,2005 International Solid Freeform Fabrication Symposium,Open,table of contents,2005 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/4011ba2d-357c-4894-991b-9d8c77e44816/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:15:55Z,2022-08-23T17:15:55Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/115368', 'http://dx.doi.org/10.26153/tsw/42268']",eng,2006 International Solid Freeform Fabrication Symposium,Open,table of contents,2006 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/f29f2722-e6c5-40b4-ac6b-3b57009ef0b7/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:17:26Z,2022-08-23T17:17:26Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/115369', 'http://dx.doi.org/10.26153/tsw/42269']",eng,2007 International Solid Freeform Fabrication Symposium,Open,table of contents,2007 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/65d3f831-0909-4c28-b78e-4a444eedbda2/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:18:39Z,2022-08-23T17:18:39Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/115370', 'http://dx.doi.org/10.26153/tsw/42270']",eng,2008 International Solid Freeform Fabrication Symposium,Open,table of contents,2008 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/09c22417-6b60-46ca-b396-49d3152d247f/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:20:00Z,2022-08-23T17:20:00Z,2009,Mechanical Engineering,,"['https://hdl.handle.net/2152/115371', 'http://dx.doi.org/10.26153/tsw/42271']",eng,2009 International Solid Freeform Fabrication Symposium,Open,table of contents,2009 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/1b9a7d9e-30db-4eae-930f-ed8924811bd7/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:21:01Z,2022-08-23T17:21:01Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/115372', 'http://dx.doi.org/10.26153/tsw/42272']",eng,2010 International Solid Freeform Fabrication Symposium,Open,table of contents,2010 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/e0adb26a-8a6a-4290-879f-b1e99a47d7b6/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:22:23Z,2022-08-23T17:22:23Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/115373', 'http://dx.doi.org/10.26153/tsw/42273']",eng,2011 International Solid Freeform Fabrication Symposium,Open,table of contents,2011 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/94bde5e9-2a8f-4162-b57b-072ff206423d/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:23:31Z,2022-08-23T17:23:31Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/115374', 'http://dx.doi.org/10.26153/tsw/42274']",eng,2012 International Solid Freeform Fabrication Symposium,Open,table of contents,2012 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/52f50796-dd3a-4553-ad69-fd6cbfbd9ea7/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:24:52Z,2022-08-23T17:24:52Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/115375', 'http://dx.doi.org/10.26153/tsw/42275']",eng,2013 International Solid Freeform Fabrication Symposium,Open,table of contents,2013 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/84cbabea-2091-41a4-89a8-98dee2468a78/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:26:12Z,2022-08-23T17:26:12Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/115376', 'http://dx.doi.org/10.26153/tsw/42276']",eng,2014 International Solid Freeform Fabrication Symposium,Open,table of contents,2014 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/cf72eabd-ec1d-43e2-b8b2-bf34cb3b3e5a/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:27:28Z,2022-08-23T17:27:28Z,2015,Mechanical Engineering,,"['https://hdl.handle.net/2152/115377', 'http://dx.doi.org/10.26153/tsw/42277']",eng,2015 International Solid Freeform Fabrication Symposium,Open,table of contents,2015 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/87232740-d486-4e83-8cc9-7082f1c2e09b/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:28:33Z,2022-08-23T17:28:33Z,2016,Mechanical Engineering,,"['https://hdl.handle.net/2152/115378', 'http://dx.doi.org/10.26153/tsw/42278']",eng,2016 International Solid Freeform Fabrication Symposium,Open,table of contents,2016 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/5a2bf1f8-5e38-49e7-b407-57a8cd4d6ad6/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-23T17:29:45Z,2022-08-23T17:29:45Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/115379', 'http://dx.doi.org/10.26153/tsw/42279']",eng,2017 International Solid Freeform Fabrication Symposium,Open,table of contents,2017 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/bc197195-896d-40da-b84e-fd90f0d10106/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-29T16:41:04Z,2022-08-29T16:41:04Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/115419', 'http://dx.doi.org/10.26153/tsw/42318']",eng,2018 International Solid Freeform Fabrication Symposium,Open,table of contents,2018 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/351ab080-bc01-403f-b38b-68a2531f2f13/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-29T16:43:07Z,2022-08-29T16:43:07Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/115420', 'http://dx.doi.org/10.26153/tsw/42319']",eng,2019 International Solid Freeform Fabrication Symposium,Open,table of contents,2019 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/d20e2a77-3afe-480b-bcdc-309bf272325b/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2022-08-29T16:44:44Z,2022-08-29T16:44:44Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/115421', 'http://dx.doi.org/10.26153/tsw/42320']",eng,2021 International Solid Freeform Fabrication Symposium,Open,table of contents,2021 International Solid Freeform Fabrication Symposium Table of Contents,Other,https://repositories.lib.utexas.edu//bitstreams/e694c010-15df-40d1-ab03-ae5e1f98140e/download,,,,,,,,
University of Texas at Austin,2024-03-25T21:56:03Z,2024-03-25T21:56:03Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124308', 'https://doi.org/10.26153/tsw/50916']",,2023 International Solid Freeform Fabrication Symposium,Open,"['preface', 'committee', '2023 Solid Freeform Fabrication Symposium']",2023 International Solid Freeform Fabrication Symposium Preface and Organizing Committee,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7b8a6d7e-421c-4530-af41-a666a67e112d/download,University of Texas at Austin,,,,,,,
"['Roosendaal, Mark D. Van', 'Chamberlain, Peter', 'Thomas, Charles']",2019-02-26T16:27:06Z,2019-02-26T16:27:06Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73481', 'http://dx.doi.org/10.26153/tsw/631']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Haar wavelet', 'Control variable']",2D Wavelet Analysis of Solid Objects: Applications in Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e7834ace-db27-4ee3-9cc8-6fa4767d8c63/download,,"In this paper, we introduce two-dimensional discrete wavelet basis functions and their
application in the analysis and modeling ofsurface topography in layered manufacturing objects.
In previous work, a one dimensional wavelet transform technique was developed to generate
variable thickness layers. [1] For vertical edge layers Haar wavelet decomposition is used the
slicing direction but is not useful in the slicing plane. For frequency analysis within the slicing
plane, biorthogonal wavelets provide the desired analysis ability. When analyzing layered
manufacturing with ruled edges a true 2-D transform is appropriate. Two-dimensional wavelet
analysis simultaneously controls the layer thickness as well as the density of control points
required the surface definition of each layer edge.",,,,,,
"['Todd, J.A.', 'Copley, S.M.', 'Yankova, M.I.', 'Fariborzi, F.', 'West, K.']",2018-11-02T16:38:38Z,2018-11-02T16:38:38Z,1995,Mechanical Engineering,doi:10.15781/T2HQ3SJ0S,http://hdl.handle.net/2152/69338,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['CAD/CAM', 'polarization', 'beam power']",3-D Laser Shaping of Ceramic and Ceramic Composite Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0873ca49-b55b-4926-a47f-ae240fb6ec24/download,,"A versatile, automated, laser-based system, capable of producing complex threedimensional
shapes of ceramic and ceramic composite materials, through either controlled layer
ablation or solid freeform fabrication, is currently under development. The system comprises
a 1.2 kW C021aser, positioning system, beam scanner, non-contacting positioning sensor, beam
conditioner and CAD/CAM system. This paper reports progress in relating machine parameters
(scan rate, feed, beam power and polarization) to process measurables (material removal rate
and surface roughness), and demonstrates the potential for rapid prototyping and direct
manufacturing of: (a) rotationally symmetric components based on ablative ceramics such as
Si3N4 and (b) graphite fuel cell plenums",,,,,,
"['Li, Xuxiao', 'Tan, Wenda']",2021-11-03T20:36:23Z,2021-11-03T20:36:23Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89926,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['grain structure', 'cellular automata', 'direct laser deposition', 'metal additive manufacturing']",3-Dimensional Cellular Automata Simulation of Grain Structure in Metal Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6bcb8670-a4ac-4b53-809c-04a1b04fbf9e/download,University of Texas at Austin,"Distinct grain structures have been observed in Metal Additive Manufacturing (MAM)
processes. These grain structures feature columnar grains which occasionally mix with equiaxed
grains. The occurrence of these grain structures is not yet fully understood. In this work, direct
laser deposition process is studied as a typical MAM process. A finite volume model is first
implemented to obtain the thermal history. Next, the thermal history is fed into a Cellular Automata
(CA) model to simulate the epitaxial and competitive growth through which the columnar grains
are formed. Nucleation is included in the model to predict the generation of equiaxed grains, and
is characterized by two nucleation parameters, the nucleation density and the critical undercooling.
The simulation results show that both the nucleation parameters and process parameters can
significantly affect the grain structure. The simulated grain structures examined on different planes
can be significantly different, revealing the complexity of the 3-dimensional grain structures in
MAM processes.",,,,,,
"['Fu, C.H.', 'Guo, Y.B.']",2021-10-18T21:41:59Z,2021-10-18T21:41:59Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89257,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'FEA', 'temperature gradient', 'molten pool']",3-Dimensional Finite Element Modeling of Selective Laser Melting Ti-6Al-4V Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7797b9a1-095c-4a81-b8c8-0dc2b11db36b/download,University of Texas at Austin,"Selective laser melting (SLM) is widely used in making three-dimensional functional parts
layer by layer. Temperature magnitude and history during SLM directly determine the molten
pool dimensions and surface integrity. However, due to the transient nature and small size of the
molten pool, the temperature gradient and the molten pool size are very challenging to measure
and control. A 3-dimensional finite element simulation model has been developed to simulate
multi-layer deposition of Ti-6Al-4V in SLM. A physics-based layer build-up approach coupled
with a surface moving heat flux was incorporated into the modeling process. The melting pool
shape and dimensions were predicted and experimentally validated. Temperature gradient and
thermal history in the multi-layer build-up process was also obtained. Furthermore, the
influences of process parameters and materials on the melting process were evaluated.",,,,,,
"['Sartin, B.', 'Pond, T.', 'Griffith, B.', 'Everhart, W.', 'Elder, L.', 'Wenski, E.', 'Cook, C.', 'Wieliczka, D.', 'King, W.', 'Rubenchik, A.', 'Wu, S.', 'Brown, B.', 'Johnson, C.', 'Crow, J.']",2021-11-02T15:25:08Z,2021-11-02T15:25:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89828,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['316L', 'metal powder', 'powder reuse', 'laser powder bed fusion', 'metal additive manufacturing']",316L Powder Reuse for Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4f71b846-370b-4e74-bf89-9434938bf7c4/download,University of Texas at Austin,"Metal additive manufacturing via laser powder bed fusion is challenged by low powder
utilization. The ability to reuse metal powder will improve the process efficiency. 316L powder
was reused twelve times during this study, completing thirty-one builds over one year and
collecting 380 powder samples. The process, solidified samples, and powder were analyzed to
develop an understanding of powder reuse implications. Solidified sample characteristics were
affected more by slight process variations than by cycling of the powder. While a small percentage
of powder was greatly affected by processing, the bulk powder only observed a slight increase in
powder size.",,,,,,
"['Xing, Juan', 'Luo, Xianli', 'Bermudez, Juliana', 'Moldthan, Matthew', 'Li, Bingbing']",2021-11-04T20:35:36Z,2021-11-04T20:35:36Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90022', 'http://dx.doi.org/10.26153/16943']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['scaffold structure', 'micro-extrusion', '3D bioprinting', '3D bioprinter']",3D Bioprinting of Scaffold Structure Using Micro-Extrusion Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e0865ee8-2284-43dd-bfbd-079e5c0109c8/download,University of Texas at Austin,"Scaffold-based techniques are a vital assistance tool to support main structure and
enhance the resolution of target structure. In this study, a custom-made micro-extrusion
bioprinting system was built and utilized to fabricate different scaffold structures such as log-pile
scaffold and two-ring scaffold. This approach showed tremendous potential because of its ability
to produce microscale channels with almost any shape. We were able to fabricate these scaffolds
by using a custom-made 3D bioprinter to print hydrogel solution, mostly composed of Pluronic
F-127, then wash away hydrogen by phosphate buffer saline (PBS) after crosslinking of main
structure. We were able to achieve the desired scaffold structure by feeding G-codes data into
user interface (Pronterface) and then translating that model into a program that utilizes a
customized programming language, which instructs the microfabrication printer nozzles to
dispense the hydrogel at specific locations. This fundamental study will be used to print
increasingly viable and complex tissue shapes with living cells.",,,,,,
"['Saleh, E.', 'Vaithilingam, J.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Hague, R.', 'Dickens, P.']",2021-10-21T20:24:21Z,2021-10-21T20:24:21Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89438,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D inkjet printing', 'silver ink', 'conductive structures', 'IR sintering']",3D Inkjet Printing of Conductive Structures using In-Situ IR sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02e64cac-9e16-42fd-9088-9655aab4a854/download,University of Texas at Austin,"In this study we investigate the inkjet printing of a silver nanoparticle ink and the
optimization of IR sintering conditions to form 3D inkjet-printed conductive structures. The
understanding of the interaction between the silver layers and the sintering conditions are key
elements to successfully build conductive tracks in 3D.
The drop size of conductive ink on glass substrates as well as on sintered conductive film was
measured to optimize the printing resolution. The resistivity of the sintered deposition was
studied in a planar X-Y direction as well as in a vertical Z direction to analyze the effects of
stacking hundreds of silver layers in different deposition orientations.
Using the results of the optimized printing and sintering conditions, conductive tracks were
demonstrated forming simple 3D inkjet-printed structures powering electronic components.",,,,,,
"['Aguiar, Daniel', 'Albuquerque, Amanda', 'Li, Bingbing']",2021-10-28T21:40:10Z,2021-10-28T21:40:10Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89707,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['bacterial cellulosic exopolysaccharide gel', 'droplet formation', '3D inkjetting', 'bioink', 'on-demand 3D printing', 'regenerative medicine']",3D Inkjetting Droplet Formation of Bacterial Cellulosic Exopolysaccharide Gel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56d89d3a-5aa8-4901-aeb7-39f7df83668f/download,University of Texas at Austin,"On-demand 3D printing of scaffolds and cell-laden structures has shown promising results
that can significantly impact human welfare. The objective is to fully understand the behavior of
bacterial cellulosic exopolysaccharide gel (BCEG) as a new bioink with low toxicity and high
biocompatibility for regenerative medicine. Its possible application is to construct scaffolds that
can be used for several biomedical applications, especially tissue engineering and treatment of
critical bone defects. By using a MicroFab inkjet micro dispenser, BCEG was dispersed to create
drops on demand that can be used to fabricate scaffolds. In order to fully understand the material’s
behavior and droplet formation, we analyzed the physical and mechanical properties of the BCEG
in different concentrations (0.1% 0.5% and 1%) and characterized it by its macroscopy,
microscopy, rheology and particle size distribution.",,,,,,
"['Ederer, Ingo', 'Hochsmann, Rainer', 'Machan, Jurgen']",2018-10-05T17:26:22Z,2018-10-05T17:26:22Z,1995,Mechanical Engineering,doi:10.15781/T2VQ2SW00,http://hdl.handle.net/2152/68717,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['CAD', '3D Printing', 'UV Curable Resins']",A 3D Print Process For Inexpensive Plastic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03db90e8-7800-4a64-a33a-b2fcf4c9e7be/download,,"Many of the currently available RP-Systems are suitable for building design models of
arbitrarily shaped parts. However, most of these RP processes use sophisticated and expensive
equipment which is not well suited for an office environment. In this paper we present a
method and an experimental device for building design models by a modified 3D print process
using plastic powder and a photopolymeric binder.",,,,,,
"['Lipton, Jeffrey Ian', 'Angle, Sarah', 'Lipson, Hod']",2021-10-18T20:11:06Z,2021-10-18T20:11:06Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89228,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['wax', 'actuator', 'robocasting']",3D Printable Wax-Silicone Actuators,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24111e76-38bd-405e-9c76-3be29d7fad4f/download,University of Texas at Austin,"The Solid Freeform Fabrication of actuators has been an area of active development. So
far only weak polymer actuators, or small displacement piezoelectric, and pneumatic
actuators have been produced. We developed a novel material platform of silicone and wax
which can be used to make soft actuators that are thermally activated. The material is made
by mechanically mixing liquid silicone and liquid paraffin wax and cooled to create a
suspension of wax particles suspended in a silicone liquid. The resulting material expands
by up to 6% of volume when heated above the wax melting temperature.",,,,,,
"['Bowa, M.', 'Dean, M.E.', 'Horn, R.D.']",2021-11-15T22:12:40Z,2021-11-15T22:12:40Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90289', 'http://dx.doi.org/10.26153/tsw/17210']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['3D printed electronics', '3D printing', 'additive manufacturing', 'sustainability', 'cost effectiveness']",3D Printed Electronics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd23a633-415a-4d98-a800-3508d6414594/download,University of Texas at Austin,"Additive manufacturing is revolutionizing the way we build and produce a plethora of
products spanning many industries. It has shown strong potential in reduced energy use,
sustainability and cost effectiveness. Exploring avenues that this technology can be utilized is key
to improve productivity and efficiencies in various applications including electronic systems and
devices manufacturing. Electronic systems and sub-systems are built using a variety of material
and processes, which require a large carbon footprint, significant waste material and high
production time. We propose the application of 3D printing technology to support an integrative
process for combining circuit board fabrication, solder mask process, electronic component pick
and place and enclosure manufacturing. The integration of these separate processes into a single
high efficiency additive manufacturing process will yield significant savings in energy use, carbon
footprint, waste product and production time and cost.",,,,,,
"['Delgado Camacho, Daniel', 'Clayton, Patricia', ""O'Brien, William J."", 'Jung, Kee Young']",2021-11-09T19:27:34Z,2021-11-09T19:27:34Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90141', 'http://dx.doi.org/10.26153/tsw/17062']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['fastener-free connections', 'additive manufacturing', '3D printing', 'material extrusion', 'polymers', 'flexural test']",3D Printed Fastener-Free Connections for Non-Structural and Structural Applications – An Exploratory Investigation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b6af235f-8e6e-424c-92d3-0560a1fc51c6/download,University of Texas at Austin,"The construction industry has shown increasing interest in AM technologies and has
successfully implemented various proof of concept projects using different AM processes. Much
of the research on AM in the construction industry has focused on development of new large-scale
extrusion printing systems and on development of cementitious materials for AM applications,
whereas research exploring new applications of already existing AM technologies and materials
suitable for construction applications has been scarce. This paper explores the use of existing,
small-scale material extrusion 3D printers to create fastener-free connections that could be used in
structural or non-structural applications. These connections, inspired by traditional wood joinery
and modern proprietary connections were printed using polylactic acid (PLA) material. The
flexural strength of the connections was then tested using a four-point bending test to evaluate
their potential structural performance and to identify connection types that warrant further research
in this exploratory proof of concept study.",,,,,,
"['Emery, B.A.', 'Revier, D.', 'Sarkar, V.', 'Nakura, M.', 'Lipton, J. I.']",2024-03-27T03:25:11Z,2024-03-27T03:25:11Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124464', 'https://doi.org/10.26153/tsw/51072']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['viscous thread printing', 'additive manufacturing', 'foam', 'stiffness']",3D Printed Intelligently Graded Functional Stiffness Foam for Sturdier Multi Stiffness Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b79a6530-9f60-453e-876a-710f992d0ad5/download,University of Texas at Austin,"Foams are ubiquitous, being used in applications such as padding, insulation, and noise isolation.
Bonding different density foams together produces undesired stress concentrations and boundary
effects. Creating controlled gradients in foam properties has been a challenge for traditional and
AM processes. Here we show how to use a form of material extrusion called Viscous Thread
APrinting (VTP) to produce foams with multiple stiffnesses and continuous gradients between
different stiffnesses. We do so by varying the path speed during extrusion to control the
production of microstructures. We compare the process of producing discrete components and
those with gradients, showing that those with gradients have higher strength in plane during
tension, have no discontinuities in out of plane stiffness, and are less prone to forming cracks at
the boundaries. We demonstrate the process in thermoplastic polyurethane (TPU).",,,,,,
"['Bryant, Nathaniel', 'Villela, Janely', 'Villela, Juan Owen', 'Alemán, Alan', 'O’Dell, Josh', 'Ravi, Sairam', 'Thiel, Jerry', 'MacDonald, Eric']",2023-01-31T14:14:39Z,2023-01-31T14:14:39Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117368', 'http://dx.doi.org/10.26153/tsw/44249']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', '3D Printed Sand Casting', 'Binder jetting', 'Curing']",3D Printed Smart Mold for Sand Casting: Monitoring Pre-Pour Binder Curing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d8799ddb-6f71-4370-8f2b-4d22dc45f35e/download,,"The benefits of additive manufacturing for fabricating complex sacrificial sand molds
for geometrically-complex metal castings is revolutionizing the foundry industry driven by a
digital manufacturing paradigm. The design freedom of 3D printing allows for new mold designs
- not possible with traditional approaches - such as helical sprues, varying wall thickness to
tailor the thermal history, and spatially-varying lattice castings. However, research on the
curing time of printed molds, including the aging of printed molds, requires more exploration.
This study describes the experimental evaluation of 3D printed specimens in which embedded
environmental sensors were fully encapsulated into sand blocks during an interruption of the
binder jetting process. Subsequently, over a 28 day duration, humidity, volatile organic
compound generation, temperature and barometric pressure were captured for three
environmental treatments. Mechanical testing of standard test specimens subjected to the same
conditions was conducted. The sand structures held in high (uncontrolled) humidity and at
reduced temperature were statistically significantly weaker than a third treatment based on the
hypothesis that high humidity and/or low temperatures impede curing. The use of embedded
sensors could provide guidelines for mold and core storage conditions as well as in high-value
production to inform the minimum (for full curing) and maximum duration (mold expiration)
after printing to identify the optimal time to pour metal during the life of a printed sand mold.",,,,,,
"['Bryant, Nathaniel', 'Villela, Janely', 'Villela, Juan Owen', 'Alemán, Alan', 'O’Dell, Josh', 'Ravi, Sairam', 'Thiel, Jerry', 'MacDonald, Eric']",2023-01-27T18:08:23Z,2023-01-27T18:08:23Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117354', 'http://dx.doi.org/10.26153/tsw/44235']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', '3D Printed Sand Casting', 'Binder Jetting', 'Curing']",3D Printed Smart Mold for Sand Casting: Monitoring Pre-Pour Binder Curing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cb79f2dd-3610-4b68-94f4-6ad603777cee/download,,"The benefits of additive manufacturing for fabricating complex sacrificial sand molds
for geometrically-complex metal castings is revolutionizing the foundry industry driven by a
digital manufacturing paradigm. The design freedom of 3D printing allows for new mold designs
- not possible with traditional approaches - such as helical sprues, varying wall thickness to
tailor the thermal history, and spatially-varying lattice castings. However, research on the
curing time of printed molds, including the aging of printed molds, requires more exploration.
This study describes the experimental evaluation of 3D printed specimens in which embedded
environmental sensors were fully encapsulated into sand blocks during an interruption of the
binder jetting process. Subsequently, over a 28 day duration, humidity, volatile organic
compound generation, temperature and barometric pressure were captured for three
environmental treatments. Mechanical testing of standard test specimens subjected to the same
conditions was conducted. The sand structures held in high (uncontrolled) humidity and at
reduced temperature were statistically significantly weaker than a third treatment based on the
hypothesis that high humidity and/or low temperatures impede curing. The use of embedded
sensors could provide guidelines for mold and core storage conditions as well as in high-value
production to inform the minimum (for full curing) and maximum duration (mold expiration)
after printing to identify the optimal time to pour metal during the life of a printed sand mold.",,,,,,
"['Munguia, J.', 'Honey, T.', 'Zhang, Y.', 'Drinnan, M.', 'Di Maria, C.', 'Bray, A.', 'Withaker, M.']",2021-10-28T21:37:15Z,2021-10-28T21:37:15Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89705,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'home-use medical device', 'redistributed manufacturing']",3D Printing Enabled-Redistributed Manufacturing of Medical Devices,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4fc126ef-f044-47a6-b46b-1fec5a5519b3/download,University of Texas at Austin,"Recently the home-use segment of medical devices has entered in the loop of Additive Manufacturing (AM)
enabled optimizations, this includes CPAP masks, insulin delivery packs and diagnostic tools such as urine-flow
meters. Here we analyze the supply chain provision of a specific uroflowmetry device which is originally designed
in Europe, manufactured in Asia and which has a range of distribution channels across healthcare systems. This
paper analyses the impact of various AM technologies that can enable near-patient manufacture of devices on-demand. Our analysis shows that the cost of design-changes (or product updates), when reflected on the overall
lifecycle cost, can be comparable to producing the device locally with a different supply chain arrangement.
Furthermore it is suggested that in order to fully exploit the capabilities afforded by AM, the original product’s
design features must be modified so that built-times are reduced allowing a larger 3D printing-based production
capacity.",,,,,,
"['McDonnell, Bill', 'Jimenez Guzman, Xavier', 'Dolack, Matthew', 'Simpson, Timothy W.', 'Cimbala, John M.']",2021-11-01T22:53:23Z,2021-11-01T22:53:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89789,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['volatile organic compounds', 'particulate matters', 'air quality', 'maker spaces', 'college', '3D printing']",3D Printing in the Wild: A Preliminary Investigation of Air Quality in College Maker Spaces,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a78b490b-10b0-46a1-b44f-d2eafb2e3c79/download,University of Texas at Austin,"Additive manufacturing is a popular method for prototyping and manufacturing custom
parts, especially on college campuses. While there is widespread use of 3D printers as part of
many engineering classwork, there is little regulation or knowledge regarding emissions. Many
plastics, including polycarbonates, ABS, and PLA are known to emit high counts of volatile
organic compounds (VOCs) and particulate matters (PMs). This study focuses on VOC and PM
counts in several natural environments and dedicated “maker spaces” on a large college campus
to gauge the exposure that students and operators experience. Emissions were measured using a
photoionization detector and two particle sizers. The photoionization detector measured total
VOCs, and the particle size counters measured both total nanoparticles and individual micro-particles based on relative particle diameter. Measurements were taken in hourly increments and
then analyzed to determine the degree with which desktop printers emitted VOCs and PM. Our
data can be used to determine whether additional ventilation or filtration is needed when 3D
printing “in the wild” to enhance operator and bystander safety.",,,,,,
"['Murphy, C.', 'Kolan, K.C.R.', 'Long, M.', 'Li, W.', 'Leu, M.C.', 'Semon, J.A.', 'Day, D.E.']",2021-10-28T21:55:10Z,2021-10-28T21:55:10Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89710,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['AD-MSCs', 'polycaprolactone', 'bioactive glass', '3D printing', 'bone repair']",3D Printing of a Polymer Bioactive Glass Composite for Bone Repair,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4cffd082-c827-4f49-950a-a53a64465504/download,University of Texas at Austin,"A major limitation of synthetic bone repair is insufficient vascularization of the interior
region of the scaffold. In this study, we investigated the 3D printing of adipose derived
mesenchymal stem cells (AD-MSCs) with polycaprolactone (PCL)/bioactive glass composite in
a single process. This offered a three-dimensional environment for complex and dynamic
interactions that govern the cell’s behavior in vivo. Borate based bioactive (13-93B3) glass of
different concentrations (10 to 50 weight %) was added to a mixture of PCL and organic solvent
to make an extrudable paste. AD-MSCs suspended in Matrigel was extruded as droplets using a
second syringe. Scaffolds measuring 10x10x1 mm3
in overall dimensions with a filament width
of ~500 µm and pore sizes ranging from 100 to 200 µm were fabricated. Strut formability
dependence on paste viscosity, scaffold integrity, and printing parameters for droplets of ADMSCs suspended in Matrigel were investigated.",,,,,,
"['Phillips, Tim', 'Allison, Jared', 'Beaman, Joseph']",2024-03-27T03:27:15Z,2024-03-27T03:27:15Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124465', 'https://doi.org/10.26153/tsw/51073']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D printing', 'resistance response', 'stress response']",3D Printing of Complex Wire Geometries for Tailored Resistance Response,Conference paper,https://repositories.lib.utexas.edu//bitstreams/89a5c9bd-8585-4111-af04-506c11fa307f/download,University of Texas at Austin,"Additive manufacturing (AM) is a rapidly growing field that enables production of
complex geometries without tooling. AM has gained traction as a method of producing complex
electronic circuits not possible using traditional techniques. The method explored in this
manuscript involves post-build infiltration of conductive inks into complex channels to create
resistive elements with tunable properties. A Polyjet printer is used to enable high-precision multimaterial components with custom mechanical properties. Further, the conductive pathway
geometry can be designed to achieve different resistive responses. These properties allow for
decoupling of the stress-strain response and resistance-strain response to produce custom strain
gauges with engineered properties.",,,,,,
"['Jayashankar, Dhileep Kumar', 'Gupta, Sachin Sean', 'Stella, Loo Yi Ning', 'Tracy, Kenneth']",2021-11-18T02:09:59Z,2021-11-18T02:09:59Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90409', 'http://dx.doi.org/10.26153/tsw/17330']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['compliant mechanism', 'passive actuation', 'additive manufacturing', 'chitosan biopolymer']",3D Printing of Compliant Passively Actuated 4D Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/204bad6d-fc3e-4435-bc6d-2577224c7bd3/download,University of Texas at Austin,"Additive manufacturing has begun to revolutionize the production of various physical technologies that
depend on bespoke geometry and tailored material properties for function. This includes the design of compliant
mechanisms, which rely on an integral coupling between geometric and material parameters to attain the elastic
flexibility necessary to accommodate programmed deformation. While kinetic structures with compliant parts are
typically activated by the application of a mechanical force, alternative means of achieving motion are available,
such as the use of smart, 4D, or stimuli-responsive materials which react to environmental conditions. In this
research, a combination of compliant mechanisms and water-responsive chitosan biopolymers was explored to
create flexible, programmable passive actuators, enabled by 3D printing. A set of compliant joints were modeled,
simulated, fabricated, and tested to determine the optimal design for use in the actuator. The actuator was then
iteratively tested with wetting and drying of chitosan films to invoke a specific shape change, which was analyzed
for accuracy, speed, and consistency. The study concluded with a discussion of the implications of synthesizing
compliant mechanisms, chitosan biopolymer, and additive manufacturing for next-generation adaptive structures.",,,,,,
"['Aguilera, Efrain', 'Ramos, Jorge', 'Espalin, David', 'Cedillos, Fernando', 'Muse, Dan', 'Wicker, Ryan', 'MacDonald, Eric']",2021-10-12T18:28:39Z,2021-10-12T18:28:39Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88715', 'http://dx.doi.org/10.26153/tsw/15649']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', '3D printed electronics', '3D printed electromechanical devices', 'hybrid manufacturing', 'structural electronics']",3D Printing of Electro Mechanical Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69e0bbf6-0b76-4137-be71-e87f225476cb/download,University of Texas at Austin,"Recent research has focused on the fabrication freedom of 3D printing to not only create
conceptual models but final end-use products as well. By democratizing the manufacturing
process, products will inevitably be fabricated locally and with unit-level customization. For 3D
printed end-use products to be profoundly meaningful, the fabrication technologies will be
required to enhance the structures with additional features such as electromechanical content. In
the last decade, several research groups have reported embedding electronic components and
electrical interconnect into 3D printed structures during process interruptions. However, to date
there appears to be an absence of fabricated devices with electromechanical functionality in which
moving parts with electronic control have been created within a single Additive Manufacturing
(AM) build sequence. Moreover, previously reported 3D printed electronics were limited by the
use of conductive inks, which serve as electrical interconnect and are commonly known for
inadequate conductivity. This paper describes the fabrication of a high current (>1 amp)
electromechanical device through a single hybrid AM build sequence using a uPrint Plus, a
relatively low cost 3D. Additionally, a novel integrated process for embedding high performance
conductors directly into the thermoplastic FDM substrate is demonstrated. By avoiding low
conductivity inks, high power electromechanical applications are enabled such as 3D printed
robotics, UAVs and biomedical devices.",,,,,,
"Mohammed, Mazher Iqbal",2024-03-27T03:29:18Z,2024-03-27T03:29:18Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124466', 'https://doi.org/10.26153/tsw/51074']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'microfluidics', '3D printing']",3D Printing of Passive Microfluidic Flow Mixers Using Triply Period Minimal Surface Microlattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb5d7ce9-7d6b-43fb-8fb3-51070148af86/download,University of Texas at Austin,"Microfluidics are miniaturised devices useful for precision fluid handling phases when
conducting a range of chemical reactions or biological processes. Such devices operate at
micrometre length scales, where laminar flow dominates and so interactions are limited to
diffusion between the flowing liquid interfaces unless flow is made turbulent to induce mixing.
Passive mixers are desirable for this task as they comprise geometrical features which can be
incorporated during the fabrication of such devices. Designs largely remain planar due to
traditional microfluidic manufacturing being conducted with 2.5D fabrication processes.
Additive Manufacturing now allows for passive mixers to now be realised in true 3D but have
seen limited investigation. This study explores the efficacy of several miniaturised Triply
Period Minimal Surface micro-lattice structures, formed within microfluidic channels as
turbulence inducing structures for increased mixing. We explore several lattice designs and
report on their efficacy for mixing reactions conducted during continuous flow conditions.",,,,,,
"['Kantareddy, S.N.R.', 'Simpson, T.W.', 'Ounaies, Z.', 'Frecker, M.']",2021-11-01T21:51:42Z,2021-11-01T21:51:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89768,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['shape memory polymers', 'shape changing polymers', '3D printing', 'additive manufacturing']",3D Printing of Shape Changing Polymer Structures: Design and Characterization of Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9fc3e69b-ed82-4002-9dc0-d58e4bcc258d/download,University of Texas at Austin,"Additive manufacturing (AM) gives engineers unprecedented design and material
freedom, providing the ability to 3D print polymer structures that can change shape.
Many of these Shape Memory Polymer (SMP) structures require multi-material
composites, and different programmed shapes can be achieved by designing and
engineering these composites to fold and unfold at different rates. To enable SMP
applications involving shape-changing geometries, it is important to have an
understanding of the relationships between intermediate shapes and the initial and final
designed shapes. To accomplish this, we investigated readily available 3D printable
polymer materials and their thermo-mechanical characteristics to create multi-member
structures. This paper demonstrates a way to generate different temporary geometric
profiles on a single 3D printed shape with the same material. This paper also includes
insights from thermo-mechanical analysis of the materials to help create multi-member
shape-changing geometries using 3D printing.",,,,,,
"['Chang, Shawn H.', 'Moser, Bryan R.']",2021-11-01T20:46:33Z,2021-11-01T20:46:33Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89743,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D printing', 'technology insertion', 'sociotechnical systems']",3D Printing Technology Insertion: Sociotechnical Barriers to Adoption,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c8bb7aac-1309-4ff7-84ab-131069a5f725/download,University of Texas at Austin,"Since the initial development of three dimensional printing (3DP) in the 1980s, companies
have relentlessly researched for applications of the technology. The potential benefit is large,
beginning with improved cost and schedule to manufacture plastic and metal articles. As such,
governments and industry from advanced economies continue to invest heavily to accelerate
3DP adoption. Amid advancements in the pillars of three dimensional printing – the
technology, material, and software – practitioners across industries are steadily deploying 3DP
in product development, prototyping, and small scale production of parts and products.
However, a large gap remains between promise and the reality of larger scale adoption. The
potential benefits, risks, and specific steps to adopt and realize the benefits are not clearly
understood, resulting in overly zealous (at risk) or overly cautious (opportunity avoided)
approaches to 3DP adoption. Traditional manufacturers rely on decades of know-how in
manufacturing practices across a large portfolio of parts, making first steps on a path to adopt
new processes more challenging.
This paper identifies the variables that complicate or impair judgement when considering the
adoption of 3DP. A systematic approach to evaluate 3DP adoption across a portfolio is needed.
A methodology is proposed to analyze the relative value of 3DP at the part and product system
level for prototyping and production. The outcome is a framework that combines part-level
feasibility with systemic benefit of cost and schedule improvements as prototyping and
production alternatives. In building this framework and in interviews with experienced
manufacturers, several key insights were gained. Part by part consideration of 3DP feasibility
is daunting, while adoption requires readiness not only of 3DP technology but also the
receiving systems and organization. By viewing 3DP insertion as a sociotechnical system
implementing the changes, attention is drawn to the tacit knowledge of critical characteristics
in existing manufacturing processes, design for manufacturing decisions embedded in existing
part assemblies, the pre-processing and post-processing capabilities available to shift 3DP
feasibilities, and the alignment of organizational learning across parts.",,,,,,
"Fly, David E.",2021-10-18T20:05:10Z,2021-10-18T20:05:10Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89225,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['composites', 'strength-to-weight ratio', 'additive manufacturing', '3D printing']",3D Printing Thin Skinned Composites to Achieve the Strength-to-Weight Ratio of Aluminum,Conference paper,https://repositories.lib.utexas.edu//bitstreams/117ac7a1-b284-494b-bcb1-017b5f6eb164/download,University of Texas at Austin,"Kevlar and stainless steel mesh reinforcements were added using epoxy to 3D printed ABS-M30
thin skins, thereby making a composite structure with significantly improved mechanical
properties over that of the 3D printed plastic alone. These additive manufactured composites
have a strength to weight ratio that is comparable to solid aluminum. Flexural 3-point bend tests
and Charpy Impact tests were conducted. Experiments were conducted that were designed to
characterize the influence of adding Kevlar to the composite structure and also the influence of
pre-mixing glass microspheres into the epoxy. These new additive manufactured (AM)
composites are an attractive choice to designers attempting to reduce weight because any 3D
printed shape can be reinforced in this manner. Additionally, actual production time is less than
3D printing a fully solid component.",,,,,,
"['Montalvo, J.I.', 'Hidalgo, M.A.']",2021-10-21T15:11:09Z,2021-10-21T15:11:09Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89390,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'reinforced filament', 'natural fiber', 'reverse engineering']",3D Printing with Natural Fiber Reinforced Filament,Conference paper,https://repositories.lib.utexas.edu//bitstreams/997f7061-9325-40d0-a371-206958e86301/download,University of Texas at Austin,"An initial study of 3d printing with compound filament using different plastic matrices and
sugar cane bagasse as the filler was conducted. In order to do this, a reverse engineering process
was made to several 3d printer extruders to determine how to change the extruder in order to be
able to print with the filament. To obtain the filament, a plastic extruder was modified to obtain a
compound filament of 1.75 mm using a 3x4 design of experiments with the factors percentage of
fiber (10% 20% 30%) and type of matrix(PE,PP,ABS,PLA). The filaments obtained were tested to
determine the mechanical properties and finally were used in a 3d printing to compare results.",,,,,,
"['Song, Yong-Ak', 'Park, Sehyung', 'Hwang, Kyunghyun', 'Choi, Doosun', 'Jee, Haeseong']",2019-02-26T17:15:15Z,2019-02-26T17:15:15Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73488', 'http://dx.doi.org/10.26153/tsw/638']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['mechanical strength', 'rapid tooling techniques']",3D Welding and Milling for Direct Prototyping of Metallic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ff65214-fd4e-4373-9d70-8be62cbf4fc0/download,,"Welding has been used for the direct fabrication of metallic prototypes and prototype tools
by several research institutes. Since welding alone is not able to deliver the accuracy and the
surface quality needed for prototype tools, especially for injection molds, a combination with
conventional machining is necessary. In this paper, welding and 5-axis milling are combined
together for the direct fabrication of metallic parts. For welding, conventional CO2 arc welding
is used. Test parts with conformal cooling channels an~ undercuts demonstrate the
technological potential ofthis process combination for rapid tooling applications.",,,,,,
"['Vaithilingam, J.', 'Saleh, E.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Hague, R.', 'Dickens, P.']",2021-10-21T19:54:35Z,2021-10-21T19:54:35Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89435,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D inkjet printing', 'drop-on-demand', 'conductive inks', 'conductive silver', 'PEDOT:PSS', 'flexible electronics', 'stretchable electronics']",3D-Inkjet Printing of Flexible and Stretchable Electronics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a4d9a27-5c78-4a2f-83b9-27cbe16b12ab/download,University of Texas at Austin,"Inkjet printing of conductive tracks on flexible and stretchable materials have gained
considerable interest in recent years. Conductive inks including inks with silver nanoparticles, carbon based inks, inks containing poly (3,4-ethylenedioxythiophene) (PEDOT)
doped with polystyrene sulfonic acid (PSS) are being researched widely to obtain a printed
electronic patterns. In this study, we present drop-on-demand inkjet printing of conductive
silver and PEDOT:PSS on a flexible and stretchable substrate. Process conditions for the
inkjet printing of silver nano-particles and PEDOT:PSS were optimised and simple
geometrical patterns (straight line and sinewave tracks) were printed. Surface profile, surface
morphology and electrical resistance of the printed patterns were examined. The printed
silver patterns were observed to be highly conductive; however when stretched, the patterns
did not conduct due to the origination of cracks. The measured conductivity for the
PEDOT:PSS patterns was significantly lower than the silver patterns; however, they
remained conductive when stretched for up to 3 mm. When flexed, PEDOT:PSS remained
conductive for a lower radius of curvature (10 mm) than the silver. Among the printed
patterns, the sinewave pattern was observed to be superior for flexible electronics application.",,,,,,
"['Wasserfall, Florens', 'Ahlers, Daniel', 'Hendrich, Norman', 'Zhang, Jianwei']",2021-10-28T22:19:47Z,2021-10-28T22:19:47Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89717,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['SMDs', 'SMD placement', 'SMD wiring', '3D-printable electronics', 'fused deposition modeling', '3D printing']",3D-Printable Electronics - Integration of SMD Placement and Wiring into the Slicing Process for FDM Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68a3b9d7-7cef-4c45-938b-94014b61a202/download,University of Texas at Austin,"Several approaches to the integration of wires and electronic components into almost every existing additive fabrication process have been successfully demonstrated by a number of research
groups in the last years. While the pure mechanical process of generating conductive wires inside
of a printed object has proved to be feasible, the design, integration, routing and generation of
toolpaths is still a laborious manual task.
In this paper, we present a novel approach to place and wire SMDs in a three-dimensional object, based on schematics generated by conventional PCB design tools such as CadSoft EAGLE.
Routing wires in an object for FDM manufacturing requires certain knowledge about the printer’s
properties to meet the extruder characteristics, avoid non-fillable regions and electric shorts. Correspondingly for the slicing of conductive wires, the software must respect appropriate channel
widths, avoid interrupted traces and ensure proper endpoints serving as contact pads for the SMDs.
To fulfill those requirements, we implemented the design and routing software as a native extension
of an existing slicing software. The user works in a three-dimensional representation of the final
extruder toolpath, augmented by the routing information. The actual computing step is executed at
the layer level by manipulating the polygons which represent the two-dimensional object topology
and toolpath for each single layer, allowing the routing algorithm to avoid the generation of nonprintable traces. We successfully designed and printed some test objects including a force-sensor
prototype, demonstrating a significant improvement in the usability and efficiency over manual
solutions.",,,,,,
"['Zhang, Feng', 'Zhang, Qiangqiang', 'Grove, Weston', 'Lin, Dong', 'Zhou, Chi']",2021-10-28T21:00:40Z,2021-10-28T21:00:40Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89699,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['micro-dispensing', 'directional freezing', '3D graphene oxide', '3D graphene aerogel', '3D printing']",3D-Printing Graphene Oxidize Based on Directional Freezing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0ab65d4b-9d07-46ab-97e8-66a36d8ecf32/download,University of Texas at Austin,"This paper aims to provide a new process that is based on micro-dispensing and directional
freezing to fabricate macro and micro controllable 3D graphene aerogel. In the first section, a
design model of the proposed system to print 3D graphene oxide is presented, and the
configurations are discussed in detail. The presented new method is contrasted to other few
graphene 3D printing process. A process planning is provided includes the complete fabrication
process and printing process. The physics mechanism behind the process is illustrated. A list of
2.5D and 3D printed samples are shown. Graphene Oxide solution is an easy to print material for
micro-dispensing device, we successfully printed GO solutions in a stable and reliable way. Our
freezing based 3D printing process matches well with freeze drying technology, which together
composes the key step for fabricating truly 3D graphene aerogel.",,,,,,
"['Wang, Qinguri', 'Tian, Xiaoyong', 'Huang, Lan']",2021-11-10T21:46:56Z,2021-11-10T21:46:56Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90187', 'http://dx.doi.org/10.26153/tsw/17108']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['4D printing', 'continuous fiber', 'composites', 'programmable morphing']",4D Printing Method Based on the Composites with Embedded Continuous Fibers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b821575-aede-49c1-8309-fb09e19e90d9/download,University of Texas at Austin,"Most of the current 4D printing technologies have the following
defects: 1) the deformation shape is simple; 2) the deforming precision is
poor; 3) the deformation process is always uncontinuous. In this study, a
new 4D printing process based on the composites with embedded
continuous fibers is proposed. In this process, a bilayer structure
consisting of the top layer of continuous fibers and the bottom layer with
resin is 3D printed. Due to the different thermal expansion coefficient and
elastic modulus of the top and bottom layers, the structure will produce
bending deformation when the temperature changes. It is found that the
curvature value and the curvature direction of the composite structure can
be precisely controlled by the angle of the intersecting fibers. The
influence of fiber trajectory on curvature is studied, and then, the
controllable deformation of any developable surface is achieved.",,,,,,
"['Cai, Jiyu', 'Vanhorn, Austin', 'Mullikin, Casey', 'Stabach, Jennifer', 'Alderman, Zach', 'Zhou, Wenchao']",2021-10-21T20:20:05Z,2021-10-21T20:20:05Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89437,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['4D printing', 'soft robotics', 'robotic facial muscles']",4D Printing of Soft Robotic Facial Muscles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/edf57068-d745-47f3-9fc1-929fa091461c/download,University of Texas at Austin,"4D printing is an emerging technology that prints 3D structures with smart materials that can
respond to external stimuli and change shape over time. 4D printing represents a major
manufacturing paradigm shift from single-function static structures to dynamic structures with
highly integrated functionalities. Direct printing of dynamic structures can provide great benefits
(e.g., design freedom, reduced weight, volume, and cost) to a wide variety of applications, such as
sensors and actuators, and robotics. Soft robotics is a new direction of robotics in which hard and
rigid components are replaced by soft and flexible materials to mimic actuation mechanisms in
life, which are crucial for dealing with uncertain and dynamic tasks or environments. However,
little research on direct printing of soft robotics has been reported. This paper presents a study on
4D printing of soft robotic facial muscles. Due to the short history of 4D printing, only a few smart
materials have been successfully 4D printed, such as shape memory and thermo-responsive
polymers, which have relatively small strains (~8%). In order to produce the large motion needed
for facial muscles, dielectric elastomer actuators (DEAs), operating like a capacitor with a sheet
of elastomer sandwiched by two compliant electrodes and known as artificial muscle for its high
elastic energy density and capability of producing large strains (~200%) compared to other smart
materials, is chosen as the actuator for our robotic facial muscles. In this paper, we report the first
fully 4D printed soft robotic face using DEAs. A literature review on DEAs is first presented. In
order to select the right material for our soft robotic face, the performance of different silicone-based candidate materials is tested and compared. A soft robotic face is then designed and
fabricated using the selected material to achieve facial emotions by the motion of its lip and pupils
actuated by the DEAs. This study demonstrates a 4D printed soft robotic face for the first time and
the potential of 4D printing of soft robotics.",,,,,,
"['Kapil, Sajan', 'Negi, Seema', 'Joshi, Prathamesh', 'Sonwane, Jitendra', 'Sharma, Arun', 'Bhagchandani, Ranjeet', 'Karunakaran, K.P.']",2021-11-04T18:08:54Z,2021-11-04T18:08:54Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89992', 'http://dx.doi.org/10.26153/16913']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['hybrid layered manufacturing', 'rapid prototyping', '5-axis cladding', '5-axis slicing', 'non-planar slicing']",5-Axis Slicing Methods for Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b4a3b44-b809-494a-a216-fd556fd90d0a/download,University of Texas at Austin,"In metallic Additive Manufacturing (AM) processes such as Hybrid Layered
Manufacturing (HLM), it is difficult to remove the support material used for realizing the
overhanging/undercut features. Multi-axis kinematics can be used to eliminate the requirement
of the support mechanism. In this work, two slicing methods have been proposed which utilize
the benefits of multi-axis kinematics to eliminate the support mechanism. In the first method,
planar slicing is used and the overhanging/undercut features are realized while keeping the
growth of the component in the conventional Z-direction. In the second method, non-planar
slicing is used, and the growth of the component need not necessarily be in the Z-direction; it
can also be conformal to the selected feature of the component. Both these methods are
explained through a case study of manufacturing an impeller by the HLM process.",,,,,,
"['Chatham, Camden A.', 'Benza, Donald W.']",2024-03-25T21:58:45Z,2024-03-25T21:58:45Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124309', 'https://doi.org/10.26153/tsw/50917']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['manufacturing', 'interface', 'engineering', 'polymer', '2023 Solid Freeform Fabrication Symposium']",A comparison of mechanical properties from natural and process-induced interfaces in filament extrusion AM of polymer blends,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d7683458-5b04-482f-a8cc-dfbbbfcdd6c8/download,University of Texas at Austin,"Polymer blends are commonly tuned for specific applications to achieve desired properties
otherwise inaccessible or prohibitively expensive to obtain via homopolymers. The interfacial
characteristics of the polymer A-polymer B interface and resultant domain sizes govern key
performance properties. Micro- and meso-scale morphology forms through the interplay of
surface forces between the polymers and between each polymer and the surrounding atmosphere.
Analogously, the layer-layer and road-road interfaces of material extrusion (MEX) additive
manufacturing (AM) govern key performance properties of printed parts. This work explores the
effect of layer height on the thermomechanical performance of polystyrene (PS)-polycarbonate
(PC) blends. Filament is prepared from a 50/50 weight ratio of the two polymers and compared
against dual-nozzle printing where every layer alternates between PS or PC homopolymer forming
a part with an overall 50/50 polymer ratio. Typical indicators of polymer blend compatibility are
also studied.",,,,,,
"['Ahmad, Nabeel', 'Bidar, Alireza', 'Ghiaasiaan, Reza', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2024-03-25T22:54:42Z,2024-03-25T22:54:42Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124329', 'https://doi.org/10.26153/tsw/50937']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'L-PBF', 'LP-DED', 'WAAM', 'Inconel 718']","A Comparison of Microstructure and Mechanical Performance of Inconel 718 Manufactured via L-PBF, LP-DED, and WAAM Technologies",Conference paper,https://repositories.lib.utexas.edu//bitstreams/dabc9dba-11ca-45d3-9c50-f5bcb709245a/download,University of Texas at Austin,"The microstructure and mechanical properties of additively manufactured (AM) alloys can be significantly
affected by variations in cooling rates, resulting from different process conditions across different additive
manufacturing (AM) platforms. Therefore, it is crucial to understand the effect of manufacturing process on the
microstructure and mechanical properties of AM Inconel 718. This study examines three AM processes: laser
powder bed fusion, laser powder directed energy deposition, and wire arc additive manufacturing. Results show
that fully heat treated laser powder bed fused (L-PBF) and wire arc additively manufactured (WAAM) Inconel
718 specimens exhibit higher strength compared to laser powder directed energy deposited (LP-DED) ones due
to finer grain structure in L-PBF and retained dendritic microstructure in WAAM. The ductility in LP-DED
Inconel 718 was slightly higher compared to WAAM and L-PBF due to relatively small carbide size, which causes
stress concentration in a small material volume, leading to delayed fracture.",,,,,,
"['Caballero, K.', 'Medrano, V.A.', 'Arrietam E.', 'Merino, J.', 'Ruvalcaba, B.', 'Ramirez, B.', 'Diemann, J.', 'Murr, L.E.', 'Wicker, R.B.', 'Godfrey, D.', 'Benedict, M.', 'Medina, F.']",2024-03-25T22:58:06Z,2024-03-25T22:58:06Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124330', 'https://doi.org/10.26153/tsw/50938']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['AlSi7Mg alloy', 'laser powder bed fusion', 'EOS M290 system', 'SLM 280HL system', 'heat treatments', 'microindentation hardness', 'mechanical properties analysis']",A comparison of the mechanical behavior of AlSi7Mg alloy produced through additive manufacturing and subjected to different heat treatment and aging conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47020d4e-3f86-4e78-a12e-e716f20fd7a1/download,University of Texas at Austin,"The versatility and adaptability of Aluminum F357 (AlSi7Mg) make it a popular material in the
aerospace and defense industries. In this study, two different laser powder bed fusion systems,
EOS M290, and SLM 280HL were used to create specimens of Aluminum F357. These
specimens were subjected to five different heat treatments: As-built, stress relief (SR), hot
isostatic pressing (HIP), T6, and HIP+T6) as per ASTM F3318-18 standard. The printed
specimens were then reduced to tensile bars through machining and tested for mechanical
properties as per ASTM E28 using an MTS Landmark tensile testing system. In addition to the
mechanical behavior analysis, the study used a JEOL JSM-IT500 SEM to observe and document
the fracture produced by the tensile test and a Qness 30 CHD Master+ microhardness testing
system to obtain hardness (HV) values of the alloy. The results showed that specimens fabricated
in the Z direction had a tendency for higher yield strengths of approximately 225 MPa and
although these results were similar between LPBF systems some variances can still be seen.
However, these differences between the LPBF systems were observed to be partially mitigated
by heat treatments. In conclusion, this study highlights the significance of heat treatment on the
mechanical properties of Aluminum F357. The results provide valuable information for the
aerospace and defense industries to optimize their processes and produce high-quality
components. The compatibility of LPBF system fabrication and the mitigation of differences
observed between LPBF machines by heat treatments, further demonstrate the potential of this
method for producing high-quality Aluminum F357 components.",,,,,,
"['Liao, A.', 'Behera, D.', 'Cullinan, M.A.']",2024-03-25T22:59:58Z,2024-03-25T22:59:58Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124332', 'https://doi.org/10.26153/tsw/50940']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'microscale', 'additive manufacturing']",A NOVEL COATING METHOD USED TO ENABLE MULTILAYER STRUCTURES WITH MICROSCALE SELECTIVE LASER SINTERING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d62c88c0-8d13-4085-a496-adb77aa3dd00/download,University of Texas at Austin,"The microscale selective laser sintering process (µSLS) is an additive manufacturing technique that
enables the creation of metal features with sub-5 µm in-plane resolution. In this process, a layer of metal
nanoparticle ink is deposited onto a substrate and positioned beneath an optical subsystem with a
nanopositioning stage. Using a digital micromirror device, a laser is spatially modulated to selectively heat up
particles in desired regions to cause sintering. The substrate is then moved to a coating station where a new layer
of nanoparticle ink is applied atop the sintered features. Initially, the slot-die coating process was adopted as
the recoating method for this technique. However, due to challenges with depositing consistent ink thickness
across the recoated part and limitations with the minimum layer thickness achievable, a new approach inspired
by blade coating has been developed to achieve layer thicknesses of less than 1 µm.",,,,,,
"['Barroi, A.', 'Schwarz, N.', 'Hermsdorf, J.', 'Bielefeld, T.', 'Kaierle, S.']",2024-03-26T22:59:55Z,2024-03-26T22:59:55Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124438', 'https://doi.org/10.26153/tsw/51046']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser wire', 'titanium', 'gas chamber']","A small volume, local shielding gas chamber with low gas consumption for Laser Wire Additive Manufacturing of bigger titanium parts",Conference paper,https://repositories.lib.utexas.edu//bitstreams/16535e1d-86a5-4f46-a466-86d85ef8debc/download,University of Texas at Austin,"This paper shows how additive manufacturing of large size titanium parts can be achieved by means of a
mobile shielding gas chamber, without the consumption of excessive amounts of shielding gas. While welding, the
oversized cover of the chamber can be slid to the sides without opening it. The laser head is only partly inserted
into the chamber through the cover. This enables a small sized chamber and allows a quick filling with argon.
Since the chamber has a low leakage, only small amounts of argon (5 l/min) are needed to maintain a sufficient
welding atmosphere with less than 300 ppm oxygen. For large sized parts, the chamber can be repositioned on the
substrate. It has flexible parts which can be fit to the already welded structures that otherwise would prevent the
chamber from being put flat on the substrate. The limited build space inside the chamber requires a new
welding strategy, which is suggested.",,,,,,
"['Dwivedi, Rajeev', 'Dwivedi, Indira', 'Panwar, Arihant', 'Dwivedi, Bharat']",2024-03-26T20:32:23Z,2024-03-26T20:32:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124398', 'https://doi.org/10.26153/tsw/51006']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['rocket', 'nozzle', 'additive manufacturing']",A Solid Free Form Fabrication Equipment to Manufacture Axisymmetric Parts with Improved Surface Quality,Conference paper,https://repositories.lib.utexas.edu//bitstreams/23219f6e-7166-4aea-b2c3-dab7969e68b5/download,University of Texas at Austin,"Competitive and Hobby grade Rocket makers quite often build custom nozzles. Solid freeform
fabrication is most natural choice for Manufacturing of the Nozzles. Different geometries can be
quickly manufactured and tested. However, staircase effect and limited accuracy of 2-1/2 based
deposition prevents the design intent from fabrication. Additionally, using different blends of ceramic
and sustaining the geometry during curing becomes challenging. This research presents a unique
3D printing system that dispenses ceramic to enable manufacturing of axi-symmetric parts as
continuous bead. Relative motion of the material dispenser and rotational substrate as well as
unique path planning enables a continually sculpted surface to reduce the staircase effects.",,,,,,
"['Ko, S.', 'Sagawa, T.', 'Yamagata, Y.', 'Aoki, S.', 'Abe, T.']",2024-03-26T23:02:23Z,2024-03-26T23:02:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124439', 'https://doi.org/10.26153/tsw/51047']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'WAAM', 'test artifact', 'inspection process', 'sphere']",A SPHERICAL TEST ARTIFACT TO EVALUATE THREE-DIMENSIONAL FORM ACCURACY FOR WIRE ARC ADDITIVE MANUFACTURING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ebe3882-a6e7-4a62-97e3-911878393aed/download,University of Texas at Austin,"Additive manufacturing, including the wire arc additive manufacturing (WAAM), is gradually
gaining attraction, and providing benefits in the aerospace and construction industries. In both
industries, large-scale manufacturing capability and quality consistency of manufactured 3D parts
are crucial. As part of quality evaluation, test artifacts for the geometric capability assessment are
specified in ISO/ASTM52902-2019(E). On the other hand, the test artifact for curved wall is left
undefined. This paper proposes a spherical shell shape as a representative of three-dimensional
shapes that are supportless and feature large overhangs, for testing the geometric capability of a
WAAM equipment. A mechanical configuration and deposition strategy are considered, which
owns the potential to universally applying for depositing large-scale parts. A quality evaluation
process for the sphere deposition was also described and experimentally demonstrated.",,,,,,
"['Jalui, S.S.', 'Spurgeon, T.J.', 'Jacobs, E.R.', 'Chatterjee, A.', 'Stecko, T.', 'Manogharan, G.P.']",2021-12-07T18:48:33Z,2021-12-07T18:48:33Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90755', 'http://dx.doi.org/10.26153/tsw/17674']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser-powder bed fusion', 'additive manufacturing', 'surface roughness', 'abrasive flow machining', 'micro-CT scanning', 'hybrid AM']",Abrasive Flow Machining of Additively Manufactured Titanium: Thin Walls and Internal Channels,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e59c70a1-7a26-4313-9c9f-1c783c890072/download,University of Texas at Austin,"Metal additive manufacturing using Laser-Powder Bed Fusion (L-PBF) technique has enabled
the metal manufacturing industry to use design tools with increased flexibility such as freeform internal
channel geometries that benefit thermofluidic applications such as heat exchangers. A primary drawback
of the L-PBF process is the as-built surface roughness, which is a critical factor in such surface-fluidic
applications. In addition, complex internal channel geometries cannot be post-processed through traditional
finishing and polishing methods, and require advanced finishing processes such as Abrasive Flow
Machining (AFM). In this original study, the effects of AM design including geometrical changes at the
inlets, internal channel and wall thickness of thin features are experimentally studied on Ti64 L-PBF parts.
A novel surface roughness inspection technique using micro-CT data is also presented. The internal
channels with larger dimensions underwent 40% improvement in surface roughness with no statistically
significant change in diameter whereas the channels with smaller dimensions and bends had a 38%
improvement in surface roughness accompanied by a 6% increase in diameter. While there was as much
as 30% improvement in surface roughness values, the thin walls less than 0.4 mm in dimension were
deformed under the AFM pressure after just 5 cycles.",,,,,,
"['Karunakaran, Rakeshkumar', 'Ortgies, Sam', 'Green, Ryan', 'Barelman, William', 'Kobler, Ian', 'Sealy, Michael']",2021-12-01T21:19:08Z,2021-12-01T21:19:08Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90616', 'http://dx.doi.org/10.26153/tsw/17535']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['magnesium', 'corrosion', 'powder bed fusion', 'fracking']",Accelerated Corrosion Behavior of Additive Manufactured WE43 Magnesium Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df537715-f19f-405b-84aa-0b393b278dc0/download,University of Texas at Austin,"Magnesium alloys are capable of withstanding the high temperatures and pressures needed
in oil and gas fracking operations followed by rapid and complete dissolution in days. Dissolvable
magnesium plugs are used in fracking to enable longer lateral wellbores by eliminating mill-outs
and the associated debris clogging. To increase extraction efficiency, the key technical challenge
is determining how to increase the strength of a high corrosion rate magnesium device that enables
higher pressures while maintaining high corrosion rates. Topologically modified dissolvable plugs
fabricated by additive manufacturing is proposed as a solution to fabricate high strength and high
corrosion rate fracture plugs. Corrosion of magnesium is dependent on surface area exposed to
corrosive media and is easily manipulated by additive manufacturing. This study highlights the
development of optimal powder bed fusion process parameters for WE43 magnesium alloy and
investigates the corrosion behavior of printed WE43 in a salt solution concentrated with sodium
bicarbonate to initiate highly accelerated corrosion. Printed WE43 corroded three times faster than
an as-rolled sample and was driven by the mechanical and materials properties formed by printing.",,,,,,
"['Pintat, T.', 'Greul, M.', 'Greulich, M.']",2018-10-04T19:57:36Z,2018-10-04T19:57:36Z,1995,Mechanical Engineering,doi:10.15781/T21C1V11T,http://hdl.handle.net/2152/68708,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SEM', 'postprocessing', 'electrodeposition']",Accuracy and Mechanical Behavior of Metal Parts Produced by Lasesrintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8417d67b-d4f4-4b3f-bdb6-18a97082d69b/download,,The work shows the mechanical properties of direct laser-sintered metal parts. The parts were tested after sintering and after an infiltration. Furthermore the accuracy of the parts was measured. Micrographs of the parts show the microstructure of the copper-nicker-tin alloy. The achievable complexity of parts is demonstrated by examples. An overview of future activities is given.,,,,,,
"['Eosoly, S.', 'Ryder, G.', 'Tansey, T.', 'Looney, L.']",2020-03-10T16:09:47Z,2020-03-10T16:09:47Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80221', 'http://dx.doi.org/10.26153/tsw/7240']",eng,2007 International Solid Freeform Fabrication Symposium,Open,selective laser sintering,Accuracy and Mechanical Properties of Open-Cell Microstructures Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6815d665-f567-474c-8c55-54aba7a0b24e/download,,"This paper investigates the applicability of selective laser sintering (SLS) for the manufacture of
scaffold geometries for bone tissue engineering applications. Porous scaffold geometries with
open-cell structure and relative density of 10-60 v% were computationally designed and
fabricated by selective laser sintering using polyamide powder. Strut and pore sizes ranging from
0.4 - 1 mm and 1.2 -2 mm are explored. The effect of process parameters on compressive
properties and accuracy of scaffolds was examined and outline laser power and scan spacing
were identified as significant factors. In general, the designed scaffold geometry was not
accurately fabricated on the micron-scale. The smallest successfully fabricated strut and pore size
was 0.4 mm and 1.2 mm, respectively. It was found that selective laser sintering has the potential
to fabricate hard tissue engineering scaffolds. However the technology is not able to replicate
exact geometries on the micron-scale but by accounting for errors resulting from the diameter of
the laser and from the manufacturing induced geometrical deformations in different building
directions, the exact dimensions of the manufactured scaffolds can be predicted and controlled
indirectly, which corresponds favorably with its application in computer aided tissue engineering.",,,,,,
"['Volpato, Neri', 'Childs, Thomas H.C.', 'Pennington, Alan de']",2019-09-23T16:14:16Z,2019-09-23T16:14:16Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75953', 'http://dx.doi.org/10.26153/tsw/3052']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Shelling,Accuracy Effects of Shelling a Part in the SLS Process 306,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba27c435-11ae-4723-b417-55134991338d/download,,"In order to reduce SLS process time in the manufacture of a mould insert, the idea of shelling the geometry of the insert has been tested. Some shelling strategies have been successful with the RapidToolTM process, proving the feasibility of the idea. It has been observed in the tests, for both polymer and RapidSteel2.0TM materials, that size accuracy, particularly of small features in the scanning (X) direction, depends on vector length (VL). When a sudden change in VL occurs, this leads to steps on the sintered surface. This paper presents both experimental observations of this and simulation results from a finite element model.",,,,,,
"['Gregorian, A.', 'Elliott, B.', 'Navarro, R.', 'Ochoa, F.', 'Singh, H.', 'Monge, E.', 'Foyos, J.', 'Noorani, R.', 'Fritz, B.', 'Jayanthi, S.']",2019-10-09T16:13:53Z,2019-10-09T16:13:53Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76150', 'http://dx.doi.org/10.26153/tsw/3239']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Prototyping,Accuracy Improvement in Rapid Prototyping Machine (FDM-1650),Conference paper,https://repositories.lib.utexas.edu//bitstreams/2a18cbee-5035-40e8-856f-efb7fa2a26d7/download,,"Over the past few years, improvements in equipment, materials, and processes have enabled
significant improvements in the accuracy of Fused Deposition Modeling (FDM) technology.
This project will investigate the present in-plane accuracy of a particular FDM machine using the
benchmark “User Part” developed by the North American StereoLithography User Group
(NASUG) and show the effect of optimal Shrinkage Compensation Factors (SCF) on the
accuracy of the prototyped parts.
 The benchmark parts were built on the FDM-1650 prototyping machine and a total of 46
measurements were taken in the X and Y planes using a Brown & Sharpe Coordinate Measuring
Machine (CMM). The data was then analyzed for accuracy using standard formulas and
statistics, such as mean error, standard deviation, residual error, rms error, etc. The optimal SCF
for the FDM-1650 machine was found to be 1.007 or 0.7%.","This work was funded by a National Science Foundation (NSF) grant to Loyola Marymount
University for their Research Experience for Undergraduates program.",,,,,
"['Pang, Thomas H.', 'Guertin, Michelle D.', 'Nguyen, Hop D.']",2018-10-10T15:33:37Z,2018-10-10T15:33:37Z,1995,Mechanical Engineering,doi:10.15781/T2X92238B,http://hdl.handle.net/2152/68755,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'SLA', 'stereolithography']","Accuracy of Stereolithography Parts: Mechanism and Modes of Distortion for a ""Letter-H"" Diagnostic Part",Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa40a594-bdda-44c1-9ce7-6b68228e4b42/download,,"Rapid Prototyping and Manufacturing (RP&M) users need to compare the accuracy of various
commercially available RP&M materials and processes. A good diagnostic test for both material and the
fabrication process involves a 4-inch long ""letter-H"" diagnostic part. This diagnostic part, known as ""H-4"", was
developed to measure the inherent dimensional characteristics ofvarious RP&M build materials. It is also less
dependent on the calibration status of particular RP&M machines, and is excellent for the purpose of generating
simple but meaningful accuracy information, which can be used to further understand the mechanism and the
modes of distortion in RP&M materials. H-4 parts were prepared and built in Stereolithography Apparatus (SLA)
using Ciba-Geigy epoxy based resins SL 5170 and SL 5180, and results were compared to acrylate based SL 5149.
Experimental data involving the magnitude, mechanism, and the modes of distortion for these three resins are
analyzed in this paper.",,,,,,
"['Crockett, R. S.', 'Horvath, T.', 'Koch, M.', 'Yang, M.']",2020-02-17T15:43:02Z,2020-02-17T15:43:02Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80014', 'http://dx.doi.org/10.26153/tsw/7039']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Accurate Heart Model for Pacemaker Development in SFF,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ecc8ca7-c7ee-4ef8-b2df-61b62028610d/download,,"Medical imaging combined with SFF techniques were used to create detailed CAD and physical
heart models for commercial development of Pacemakers. Using a data set of 2D optical slice
images of the human heart at 1mm spacing obtained from the Visible Human Project, a 3D CAD
model was constructed by masking the features of interest in each slice. Normals on the
resulting .stl file were inverted to create a single-piece mold, which was built in starch using 3D
Printing. Flexible silicone was cast into this mold, and the starch was dissolved away to produce
the final physical heart model. The resulting model simulates the mechanical properties of an
actual heart, with medically accurate internal and external details including major veins &
arteries, coronary sinus, etc.",,,,,,
"Levi, Heim",2018-04-16T17:40:17Z,2018-04-16T17:40:17Z,1991,Mechanical Engineering,doi:10.15781/T2513VC7R,http://hdl.handle.net/2152/64312,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'Solid Ground Curing Technology', 'stereolithography']",Accurate Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2e4f5af-9514-4e14-b1aa-d8ab1316fe14/download,,"The first stage of Rapid Prototyping life cycle as a new technology
in the marketplace is gradually ending, and the second stage has
already started. Many new vendors have introduced their products in
this field, utilized different, new technologies or improvements of
the existing ones. The first introduction of the RP concept and
Stereolithography created a stunning impression in the marketplace.
After a couple of years, as customers and users have gained much
experience and understanding or RP technology, the first enthusiasm
started making way to more serious and demanding approach. This is
very well reflected in the thorough evaluations of the different
technologies available today in the marketplace, done by customers
looking for a technology that will best fit their needs. This is
actually why most of us are here today.",,,,,,
"['Loney, D.A.', 'Zhou, W.', 'Rosen, D.W.', 'Degertekin, F.L.', 'Fedorov, A.G.']",2021-09-30T13:33:59Z,2021-09-30T13:33:59Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88240', 'http://dx.doi.org/10.26153/tsw/15181']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['acoustics', 'Additive Manufacturing via Microarray Deposition', 'ultrasonic atomizer', 'high viscosity fluid injection', '3D inkjet manufacturing']",Acoustic Analysis of Viscous Fluid Ejection Using Ultrasonic Atomizer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b9a63a6-f12b-4c12-bda1-4baac0a43cca/download,University of Texas at Austin,"The acoustics of the Additive Manufacturing via Microarray Deposition (AMMD) system
based on a ultrasonic atomizer is investigated for printing high viscosity fluids for 3D inkjet
manufacturing applications. The ultrasonic atomizer incorporates a piezoelectric transducer, a
material reservoir, and a silicon micromachined array of acoustic horn structures as ejection
nozzles. When driven at the resonance frequencies of the fluid cavity, the nozzle geometry
focuses the acoustic waves resulting in a locally increased pressure gradient at the nozzle apex.
Previously, AMMD has demonstrated successful ejection of fluids with viscosity as high as 3000
mN-s/m2, overcoming the viscosity limitations traditionally associated with piezoelectric droplet
formation. However, the physics of ejection of such high-viscosity fluids is not well understood.
This work focuses on understanding the acoustics of the AMMD system through complimentary
simulations and experimental characterization. Specifically, ANSYS finite element software was
used to model acoustic wave attenuation due to viscosity inside the material cavity and its
implication on the pressure gradient at nozzle apex, which drives the fluid ejection.
Additionally, the affect of fluid attenuation on cavity resonance modes, both the frequency and
the quality factor, is characterized for fluids of a large variation range in viscosity. Finally,
preliminary guidelines for improved design and efficient operation of the AMMD system are
formulated based on an insight into a device’s acoustic behavior with high viscosity fluids.",,,,,,
"['Kouprianoff, D.', 'Luwes, N.', 'Yadroitsava, I.', 'Yadroitsev, I.']",2021-11-15T21:53:40Z,2021-11-15T21:53:40Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90283', 'http://dx.doi.org/10.26153/tsw/17204']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['online monitoring', 'online detection', 'acoustic emission', 'fusion defect', 'balling effect', 'single tracks', 'metal laser powder bed fusion']",Acoustic Emission Technique for Online Detection of Fusion Defects for Single Tracks During Metal Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/34ddc76c-8dca-4f50-940a-5a7e46a3e6c1/download,University of Texas at Austin,"One of the main drawbacks of laser based powder bed fusion, is lack of fusion
between tracks due to non-optimal input process parameters, scanning and building
strategies and/or inhomogeneity in the delivered powder layer. Unstable geometrical
characteristics of single tracks and high roughness of the powder layer can cause porosity in
3 dimensional printed parts. In this study a non-destructive online monitoring technique,
using acoustic emission was utilized to determine lack of fusion and balling effect of single
tracks. This phenomenon was simulated by using an increased powder layer thickness. Short
Time Fourier Transform was used as a tool for analysis of the acoustic behaviour of the
system and it was compared with the acoustic emission (AE) recorded during processing of
single tracks.",,,,,,
"['Khurana, Jivtesh B.', 'Dinda, Shantanab', 'Simpson, Timothy W.']",2021-11-04T14:39:17Z,2021-11-04T14:39:17Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89971,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['active z printing', 'part strength', '3D printing', 'fused filament fabrication', 'design of experiments']",Active - Z Printing: A New Approach to Increasing 3D Printed Part Strength,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7ebc85b-565f-4137-9864-baca0e739b29/download,University of Texas at Austin,"Research suggests that topology and build parameters in Fused Filament Fabrication (FFF)
play a vital role in determining mechanical properties of parts produced by this technique. In
particular, the use of 2D layers printed parallel to the build surface produces high anisotropy in
parts making them the weakest when loaded perpendicular to the layer interfaces. We investigate
a novel approach that uses non-planar 3D layer shapes - Active Z printing, to improve mechanical
strength through alignment of localized stress tensors parallel to the deposition paths. Sinusoidal
layer shapes are used with varying amplitude, frequency, and orientation. Design of experiments
is performed to correlate effect of varying shape and orientation of sinusoidal layer shapes on
flexural strength of parts. Based on this, the results are used to decide parameters to be studied
further and characterize their effect on the strength of parts.",,,,,,
"['Saari, M.', 'Galla, M.', 'Cox, B.', 'Richer, E.', 'Krueger, P.', 'Cohen, A.']",2021-10-19T17:40:27Z,2021-10-19T17:40:27Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89306,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Fiber Encapsulation Additive Manufacturing', 'electromechanical devices', 'active devices', 'device fabrication']",Active Device Fabrication Using Fiber Encapsulation Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/06b4b2b7-fdce-4e28-b6d3-4280f5b6ec34/download,University of Texas at Austin,"Fiber Encapsulation Additive Manufacturing (FEAM) is a novel solid freeform
fabrication process in which a fiber and a matrix are co-deposited simultaneously within a single
printer along straight and curved 2-D and 3-D paths. Using a FEAM approach in which the fiber
is a metal wire and the matrix is a thermoplastic polymer, simple electromechanical devices such
as voice coils, inductive sensors, and membrane switches have been successfully produced. This
paper will present an overview of the FEAM process, describe several fabricated devices, and
discuss recent developments in controllably stopping and starting the wire, and in creating
electrical junctions between individual wires, which together enable much more complex devices
to be made.",,,,,,
"['Adams, Gavin', 'Meisel, Nicholas']",2024-03-26T16:53:19Z,2024-03-26T16:53:19Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124371', 'https://doi.org/10.26153/tsw/50979']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['continuous carbon fiber', '3D printing', 'DfAM', 'additive manufacturing']",ADAPTING A DESIGN FOR ADDITIVE MANUFACTURING WORKFLOW TO ACCOUNT FOR CONTINUOUS CARBON FIBER REINFORCED PARTS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dbfa8d81-6e41-46ce-a646-31e62981f667/download,University of Texas at Austin,"The use of continuous carbon fiber (CCF) reinforcement in material extrusion 3D printing has the
potential to revolutionize the material extrusion field of additive manufacturing. Notably, the
Markforged X7 system utilizes this CCF reinforcement with the aim to produce parts with
mechanical results rivaling or surpassing those of aluminum. However, due to certain constraints
with the deposition of CCF in material extrusion parts, such as an inability for CCF to be deposited
throughout layers in the Z-direction, traditional design for additive manufacturing (DfAM)
techniques need to be reevaluated. This paper will explore (1) how existing DfAM considerations
(e.g., topology optimization, functional integration, minimum feature size, etc.) can be tailored to
CCF and (2) how an existing DfAM workflow can be adapted to account for manufacturing
limitations specific to the deposition of CCF. The research is demonstrated through a hoist sling
case study, which highlights the importance of considering fiber orientation and routing in the
design stage to ensure accurate CCF reinforcement and achieve ideal mechanical results relative
to the loads associated with the part. The result is an initial, potentially valuable workflow for
designing CCF parts to be created using AM.",,,,,,
"Boudreaux, J.C.",2018-11-16T14:47:59Z,2018-11-16T14:47:59Z,1996,Mechanical Engineering,doi:10.15781/T2V40KJ88,http://hdl.handle.net/2152/70282,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLA', 'SFF', 'SLS']",An Adaptive Control Architecture for Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbf0c01a-b372-4c8b-8650-15fe3aea5261/download,,,,,,,,
"['Vouzelaud, F.A.', 'Bagchi, A.']",2018-04-19T18:36:20Z,2018-04-19T18:36:20Z,1992,Mechanical Engineering,doi:10.15781/T2QB9VP36,http://hdl.handle.net/2152/64411,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'FFF', 'free form frabrication']",Adaptive Laminated Machining for Prototyping of Dies and Molds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/21a83f11-db41-490f-8a01-3a16686bdbdf/download,,"Adaptive laminated machining is the fusion of slicing a solid model into layers and producing parts by CNC
milling machines. Unlike other solid freeform fabrication processes which create the part by addition of
material, adaptive laminated machining can create solid parts by selectively removing in layers. The
research issues and practical limitations on shape and manufacturability are thus different from other
processes. However, the biggest advantage is the ability to obtain a solid metal part such as a die or a
mold directly. In this paper, the concept of this technique, and initial results and parts produced in Clemson
will be presented. In addition, future research needs and issues will be discussed.",,,,,,
"Chalavadi, Pradeep",2024-03-27T03:35:56Z,2024-03-27T03:35:56Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124469', 'https://doi.org/10.26153/tsw/51077']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['adaptive meshing', 'octree data structure', 'voxel-based mesh', 'additive manufacturing']",ADAPTIVE MESHING FRAMEWORK USING OCTREE DATA STRUCTURE FOR VOXEL BASED MESHES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a6afdf34-6629-47bf-a9d5-e68bc46a1f6b/download,University of Texas at Austin,"We present an adaptive meshing framework for voxel-based meshes, designed for use in
various process simulations for additive manufacturing, such as thermal, distortion, grain growth,
etc. The framework uses an octree data structure to represent the meshes, and a
coarsening/refinement algorithm to generate coarser and finer meshes. The algorithm preserves a
2:1 ratio of coarse to fine meshes to maintain desired accuracy. Efficient tree traversal is used for
fast nodal/Gaussian solution mapping. In many cases, selective element coarsening enables the
reduction of the number of nodes to be solved by the iterative matrix solver. To maintain accuracy
at boundary, the algorithm can be configured to maintain a certain level of fine mesh at boundary.
When part and support mesh touch, they are automatically flagged to be not combined to be
coarsened at any stage. Overall, the algorithm enables reduction of solution nodes while
maintaining desired accuracy at areas of interest.",,,,,,
"['Xiangping, Wang', 'Haiou, Zhang', 'Guilan, Wang', 'Lingpeng, Wu']",2021-10-18T22:38:58Z,2021-10-18T22:38:58Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89275,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Hybrid Plasma Deposition and Milling', 'adaptive slicing', 'multi-axis layered manufacturing']",Adaptive Slicing for Multi-Axis Hybrid Plasma Deposition and Milling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ae1bbb8-3c7f-4d0a-8ccf-54169ea147d8/download,University of Texas at Austin,"Hybrid Plasma Deposition and Milling (HPDM), a five-axis manufacturing
system integrated material additive and subtractive processes, can be used to create
overhang metallic components directly without the usage of sacrificial support
structure. Different from conventional slicing methods, a new slicing algorithm with
changeable direction and thickness is proposed in this paper. Minimal overhang length
is selected as the objective function to optimize the build direction. The thickness is
adjusted to meet allowable overhang length and allowable cups height. The input
mesh is first decomposed into non-uniform thickness segment meshes and then each
segment is cut into uniform thickness slices. The output slices consist of split slices
between two adjacent segment meshes and inner slices for each segment mesh.
Examples and analyses confirm the feasibility and effectiveness.",,,,,,
"['Suh, Young Seok', 'Wozny, Michael J.']",2018-10-03T18:40:57Z,2018-10-03T18:40:57Z,1994,Mechanical Engineering,doi:10.15781/T21J97T0Z,http://hdl.handle.net/2152/68677,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SFF', '3D aliasing', 'CAD']",Adaptive Slicing of Solid Freeform Fabrication Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b6f350a7-565a-4911-baf9-5ff682c022be/download,,"The Solid Freeform Fabrication (SFF) process significantly reduces part specific setup
manufacturing lead time. This process has been primarily used in fabricating prototypes for design
visualization and verification. However, the major impact of this process on the future of
manufacturing technology would be the possibility offabricating functional parts for end use. One
ofthe obstacles to this goal is the insufficient accuracy ofthe final physical part produced by the
process. From the software point of view, the major sources of the inaccuracy come from the
inappropriate data transfer format and the 3D aliasing' or Stair-stepping' problem.
The '3D aliasing' problem can be reduced by adapting the layer thickness to the geometry of
the part. In this paper, the procedure of adaptive slicing from the exact representation ofthe part
model is described. This will improve part accuracy and minimize building time especially for the
parts with highly curved surfaces. The procedures are implemented and a comparison to the
conventional uniform layer thickness method will be discussed.",,,,,,
"['Unnanon, Kittnan', 'Cormier, Denis', 'Sanii, Ezat']",2019-09-23T15:58:28Z,2019-09-23T15:58:28Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75947', 'http://dx.doi.org/10.26153/tsw/3046']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Inkjet,Adaptive Slicing With the Sanders Prototype Inkjet Modeling System 259,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb087c21-10e9-41e5-aaff-a468ef14be59/download,,"This paper presents one of the first known in depth studies of the Sanders Prototype inkjet modeling process. A process capability study was performed in order to determine the relationship between process parameter levels and the resulting surface roughness. The data was used to create a predictive model of surface roughness using a backpropagation neural network. Test results indicate that the network is quite effective at generalizing to new process configurations. The predictive surface roughness model is used in a newly developed inkjet modeling adaptive slicing algorithm. On a region-by-region basis, the algorithm determines the fastest machine configuration that can be used to build a part while satisfying the surface roughness requirements. The adaptive slicing system has been tested, and results documenting substantial time and cost savings are presented.",,,,,,
"['Coulson, Kevin', 'Toombs, Joseph', 'Gu, Magnus', 'Taylor, Hayden']",2021-12-06T23:50:41Z,2021-12-06T23:50:41Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90723', 'http://dx.doi.org/10.26153/tsw/17642']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['adaptive voxelization', 'computed axial lithography', 'printing generation', 'compensational time']",Adaptive Voxelization for Rapid Projection Generation in Computed Axial Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ee4836f-55c2-4eda-8376-d6b0ccb7483e/download,University of Texas at Austin,"Computed axial lithography (CAL) is a tomographic additive manufacturing technology
that offers exceptionally fast printing in a wide range of materials. CAL involves pre-computing
a sequence of light patterns to be projected into a photopolymer. For a uniform spatial
discretization of the target geometry, computational time scales inversely with the cube of the
discretization pitch, which makes it challenging to exploit the full space-bandwidth product of
available spatial light modulators. This work introduces an adaptive voxelization approach to
reduce computational expense. Using one of several proposed mesh-based complexity analyses,
a CAD model is recursively subdivided into stacked sub-meshes of varying voxel resolution.
These complexity methods can be tailored to emphasize complexity in particular regions. Each
sub-mesh is then independently voxelized before projections are generated and optimized in
parallel. On a four-core CPU, this method results in a 2 − 6 × speedup with applications in high-precision CAL and other voxel-based additive manufacturing computations.",,,,,,
"['Shusteff, Maxim', 'Panas, Robert M.', 'Henriksson, Johannes', 'Kelly, Brett E.', 'Browar, Allison E.M.']",2021-10-28T15:39:37Z,2021-10-28T15:39:37Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89665,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['holographic lithography', 'additive manufacturing', '3D structures']",Additive Fabrication of 3D Structures by Holographic Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9bceeb91-6f5c-4e8f-b172-7015d7b86823/download,University of Texas at Austin,"As additive manufacturing (AM) technologies advance and mature, the geometric
constraints imposed by fabricating 2D planar layers become increasingly important to overcome.
In the realm of light-driven AM fabrication, holography provides a promising avenue toward true
3D structures. Being capable of recording and reconstructing 3D information, holographic
shaping of the light field can enable direct 3D fabrication in photopolymer resins. We have
conceptualized, designed, and built a prototype holographic additive micromanufacturing
system, incorporating a liquid-crystal-on-silicon (LCoS) spatial light modulator (SLM) to
redirect light energy at the build volume by spatial control of the phase distribution. Here we
report the system design, design parameter trade-offs relevant for producing 3D structures, and
initial fabrication results.",,,,,,
"['Ramesh, S.', 'Eldakroury, M.', 'Rivero, I.V.', 'Frank, M.C.']",2021-11-04T20:59:48Z,2021-11-04T20:59:48Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90027', 'http://dx.doi.org/10.26153/16948']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['bioplotting', 'chitosan', 'cryomilling', 'additive fabrication', 'bone tissue engineering']",Additive Fabrication of Polymer-Ceramic Composite for Bone Tissue Engineering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6823bbbd-6dba-4100-8ea5-d11353d371a0/download,University of Texas at Austin,"The objective of this study is to manufacture chitosan-based biocomposite 3-D scaffolds through
additive fabrication for promoting the regeneration of bone defects. Additive manufacturing has
enabled the production of effective scaffolds by overcoming traditional limitations such as
suboptimal distribution of cells, and poor control over scaffold architecture. In this study,
cryomilled biocomposites comprising of poly (lactic) acid (PLA), chitosan (CS) and tricalcium
phosphate (TCP) provided the basis for the generation of hydrogels, which were then utilized for
the fabrication of scaffolds with orthogonal (0, 90) geometry. Rheological studies were conducted
using a rotational rheometer to identify the ideal hydrogel concentration for the continuous
production of scaffolds. The scaffolds were fabricated using a 3-axis computerized numerical
control (CNC) which was modified to function as a customized bioplotter. Scanning electron
microscopy (SEM) was used to observe the morphology of the bioplotted scaffolds. Finally, a
short-term stability (14 days) study was conducted to analyze the in vitro degradation behavior of
the scaffolds in phosphate buffer saline (PBS).",,,,,,
"['Bandari, Yashwanth K.', 'Williams, Stewart W.', 'Ding, Jialuo', 'Martina, Filomeno']",2021-10-19T15:47:24Z,2021-10-19T15:47:24Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89305,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacture', 'direct feed', 'robotics', 'cost']",Additive Manufacture of Large Structures: Robotic or CNC Systems?,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6cb88baa-342a-447d-b878-8f44a89f9440/download,University of Texas at Austin,"Additive manufacture of metre scale parts requires direct feed processes such as blown powder or wire
feed combined with lasers or arcs. The overall system can be configured using either a robotic or Computer
Numerical Controlled (CNC) gantry system. There are many factors that determine which of these is best and
this will be presented in this paper. Some factors are inherent to the specific process type such as
accuracy/resolution and any requirement for reorientation of the feedstock and heat source. Other factors
depend on the particular application including material type, shielding options, part size/complexity, required
build strategies and management of distortion. Further considerations include the incorporation of ancillary
processes such as cold work, machining or inspection. The relative influence of these factors will be discussed.
Cost implications for the different approaches will be highlighted based upon the type of process being utilized.
Examples are provided where both robotic and CNC options have been evaluated and the best solution found.",,,,,,
"['Aydin, I.', 'Akarcay, E.', 'Gumus, O.F.', 'Yelek, H.', 'Engin, C.B.']",2021-11-30T22:13:34Z,2021-11-30T22:13:34Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90567', 'http://dx.doi.org/10.26153/tsw/17486']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'finite element analysis', 'lattice structures', 'maraging steel', 'mechanical properties', 'vehicle door hinge']",Additive Manufactured Lightweight Vehicle Door Hinge with Hybrid Lattice Structure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f98a37b5-6776-4877-930b-6998f55c0a90/download,University of Texas at Austin,,,This paper presents an approach to finite element analysis of regulation to simulate mechanical behavior of door hinge with hybrid lattice structures.,,,,
"['Ivanova, Olga S.', 'Williams, Christopher B.', 'Campbell, Thomas A.']",2021-10-05T15:12:05Z,2021-10-05T15:12:05Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88390', 'http://dx.doi.org/10.26153/tsw/15329']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'nanomaterials', 'nanotechnology', 'AM technologies']",Additive Manufacturing (AM) and Nanotechnology: Promises and Challenges,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b578771f-89c4-4e6a-bd1b-26e42d0cc50a/download,University of Texas at Austin,"The narrow choice of materials used in Additive Manufacturing (AM) remains a key
limitation to more advanced systems. Nanomaterials offer the potential to advance AM materials
through modification of their fundamental material properties. In this paper, the authors provide
a review of available published literature in which nanostructures are incorporated into AM
printing media as an attempt to improve the properties of the final printed part. Specifically, we
review the research in which metal, ceramic, and carbon nanomaterials have been incorporated
into AM technologies such as stereolithography, laser sintering, fused filament fabrication, and
three-dimensional printing. The purpose of this article is to summarize the research done to date,
to highlight successes in the field, and to identify opportunities that the union of AM and
nanotechnology could bring to science and technology.",,,,,,
"['Dickens, Phill', 'Reeves, Phill', 'Hague, Richard']",2021-10-05T15:29:56Z,2021-10-05T15:29:56Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88391', 'http://dx.doi.org/10.26153/tsw/15330']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Additive Manufacturing education', 'UK', 'Institution of Mechanical Engineers']",Additive Manufacturing Education in the UK,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e6899cc-83af-46f7-8dfb-127718e382fb/download,University of Texas at Austin,"There has been and continues to be a considerable effort regarding education for
Additive Manufacturing (AM) in the UK. This generally started in 1992 with a seminar
organised by the Institution of Mechanical Engineers and an industrial exhibition stand
at Mach 92. However, before the education activities are discussed it is useful to show
the AM research landscape in the UK as this will give an indication of the level of activity
It should be noted that there will also be a considerable number of organisations
involved in using AM but not involved in research.",,,,,,
"['Dey, N.K.', 'Liou, F.W.', 'Nedic, C.']",2021-10-12T17:55:55Z,2021-10-12T17:55:55Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88707', 'http://dx.doi.org/10.26153/tsw/15641']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser deposition', 'titanium', 'Ti-6Al-4V', 'aerospace repair']",Additive Manufacturing Laser Deposition of Ti-6Al-4V for Aerospace Repair Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/895a2fc0-e880-4da6-aa51-6a01b0fbbcc8/download,University of Texas at Austin,"Parts or products from high performance metal are very
expensive, partly due to the processing complexities during
manufacturing. The purpose of this project is to use additive
laser deposition and machining processes to repair titanium
parts, thus extending the service life of these parts. The study
broadly included preparing the defects, laser deposition,
machining, sample preparation and mechanical tests.
Comparative study of mechanical properties (UTS, YS,
percentage elongation) of the repaired samples to the ideal
conditions was undertaken. The research throws up interesting
facts where the data from the test sample shows enhancement of
properties of the repaired part.",,,,,,
"['Knapp, C.M.', 'Lienert, T.J.', 'Chen, C.', 'Kovar, D.']",2021-10-12T22:25:13Z,2021-10-12T22:25:13Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88755', 'http://dx.doi.org/10.26153/tsw/15689']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['direct metal deposition', 'Laser Engineered Net Shaping', 'AISI 1018 steel', 'heat-affected zone', 'steel substrates', 'microstructure', 'additive manufacturing']",Additive Manufacturing of 1018 Steel: Process Observations and Calculations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8df7da2-641d-451e-a0e5-f5c758037e0a/download,University of Texas at Austin,"The temperature distribution in the vicinity of the laser used in direct metal deposition
(DMD) plays a critical role in determining the final microstructure and mechanical properties of
the deposit and the heat-affected zone (HAZ) within the substrate. Samples were prepared using
Laser Engineered Net Shaping (LENSTM) by depositing AISI 1018 steel powder onto AISI 1018
steel substrates in multiple, overwritten passes. The laser power and speed were varied to control
the heat input and the rate of cooling. The process characteristics were then quantified and
compared across the samples to determine the effect of input parameters on the resulting deposit
microstructures.",,,,,,
"['Tsui, Lok-kun', 'Maines, Erin', 'Evans, Lindsey', 'Keicher, David', 'Lavin, Judith']",2021-11-10T21:14:14Z,2021-11-10T21:14:14Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90177', 'http://dx.doi.org/10.26153/tsw/17098']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['UV curable resin', 'alumina pastes', 'in-situ', 'material extrusion', 'printing', 'additive manufacturing']",Additive Manufacturing of Alumina Components by Extrusion of In-Situ UV-Cured Pastes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eeb89f9c-c6b5-47e3-b23f-f3d91a6f49ba/download,University of Texas at Austin,"Additive manufacturing of ceramic materials is an attractive technique for rapid
prototyping of components at small scales and low cost. We have investigated the printing of
alumina pastes loaded at 70-81.5 wt% solids in a UV curable resin. These can be deposited by
extrusion from a syringe head on a Hyrel System 30M printer. The print head is equipped with an
array of UV LEDs, which solidify the paste without the need for any applied heating. Parameters
optimized include print speed, layer height, applied force, and deposition rate. Using A15 alumina
and submicron A16 powder precursors, we can achieve bulk densities of 91% and 96% of
theoretical density respectively. The influence of dispersants and surfactants added to the powder
on the rheology of the pastes, the print process parameters, and the quality of the final components
are also investigated.",,,,,,
"['Girdis, Jordan', 'McCaffrey, Matthew', 'Proust, Gwénaëlle']",2021-10-27T22:48:47Z,2021-10-27T22:48:47Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89638,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'short carbon fibers', 'graphene', 'polymer composites']",Additive Manufacturing of Carbon Fiber and Graphene – Polymer Composites using the technique of Fused Deposition Modelling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be914ffc-d48c-4bd0-ab34-064a97b61cbd/download,University of Texas at Austin,"Adding micro or nano-carbon reinforcements to polymers enhances their mechanical
and electrical properties. In this paper, the effects of the addition of short carbon fibres (SCF)
and graphene into acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) polymer
to create composite filaments for fused deposition modelling (FDM) are investigated. After
creating carbon polymer composite filaments, using a commercial 3D printer, samples were
printed and tested for mechanical and electrical properties. The measured values for these
composites were compared to those obtained for pure ABS and pure PLA. It was found that
by using only 2% SCF it was possible to achieve a 22% increase in tensile strength with no
significant impact on printability. With addition of graphene, PLA was made to be
conductive. These results show the feasibility of developing new materials for 3D printing
that will create structurally sound and conductive designs.",,,,,,
"['Zhang, Xinchang', 'Pan, Tan', 'Chen, Yitao', 'Liou, Frank']",2021-12-06T22:48:08Z,2021-12-06T22:48:08Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90704', 'http://dx.doi.org/10.26153/tsw/17623']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'functionally graded materials', 'Cu', 'stainless steel', 'dissimilar materials']",Additive Manufacturing of Cu on 316L Stainless Steel via Inconel 718 Intermediate Layers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed6892db-8d24-45b3-92bd-083a4bef3302/download,University of Texas at Austin,"Joining of dissimilar materials is becoming increasingly prevalent to combine differing
material properties to enhance product design flexibility and performance. In this study, pure
copper was built on 316L stainless steel (SS316L) by laser-based additive manufacturing
technology in which copper was deposited layer-by-layer on SS316L with Inconel 718
intermediate layers. The goal is to fabricate multi-metallic structures with improved thermal
conductivity. The direct joining of Cu on SS316L would result in porosities at the interface and
the consequent poor mechanical properties, which could be addressed by Inconel 718 intermediate
layers. The microstructure, chemical composition, tensile properties, and micro-hardness were
characterized in the dissimilar materials using scanning electron microscopy, energy dispersive
spectroscopy, tensile test with digital image correlation technique, and hardness tester. Results
confirm excellent bonding when Inconel 718 intermediate layers are introduced.",,,,,,
"['Kulkarni, P.M.', 'Karunakaran, K.P.', 'Tewari, Asim', 'Legesse, Fisseha', 'Rana, Dhirendra', 'Bernard, Alain']",2021-10-18T20:21:34Z,2021-10-18T20:21:34Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89231,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['directional heat condctuve', 'Additive Manufacturing', 'Hybrid Layered Manufacturing']",Additive Manufacturing of Directionally Heat Conductive Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e433d7a-bce0-4854-b80f-12c723d9bedd/download,University of Texas at Austin,"Purpose: Directionally Heat Conductive (DHC) objects are also known as thermal cables. DHC
objects used in cooling solid state devices as large heat sinks. This paper presents Additive
manufacturing (AM) as a new method for realization of DHC objects. AM can produce DHC
objects accurately, rapidly and economically.
Design/Methodology/Approach: It is very hard to realize DHC objects through conventional
manufacturing. The authors describe the realization of metallic DHC objects using their AM
process called Hybrid Layered Manufacturing (HLM). HLM, which uses GMAW deposition, can,
in principle, produce DHC out of any metal for which welding wire is available. . Differential
conductivity in HLM is achieved by appropriately distributing the air gaps among the beads. The
air gap distribution depends on the layer thickness and step over increment.
Findings: The authors have demonstrated the ability of HLM to produce DHC objects for Al alloy
4043. The thermal conductivity achieved on two orthogonal directions was 100.496 and 129.740
W m-1 K-1 as against 163 W m-1 K-1 for solid metal. These are significant variations.
Research Limitations/Implications: HLM realize near net shape of DHC objects, further post
processing namely machining is required.
Originality Value: AM Specifically HLM for realization of DHC objects",,,,,,
"['Chiroli, M.', 'Ciszek, F.', 'Baschung, B.']",2021-11-10T21:28:55Z,2021-11-10T21:28:55Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90181', 'http://dx.doi.org/10.26153/tsw/17102']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['energetic materials', '3D printing', 'additive manufacturing', 'defense industry']",Additive Manufacturing of Energetic Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4ca2a243-91de-479e-829f-193d798a5294/download,University of Texas at Austin,"Over the last decade, additive manufacturing gained a lot of interest within the defense
industry. However, printing energetic materials such as explosives or solid propellants remains
a challenge. A research work with the aim to suggest appropriate materials and associated 3D
printing techniques to produce energetic materials, is currently carried out. In interior ballistics,
improved weapon performance ends in reaching higher muzzle kinetic energy. This can be
achieved by adjusting the gas pressure released during the ballistic cycle by using specific
propellant grains. A former study (Baschung, MRS Symposium H, Boston, 2005) highlighted
the advantages of using co-layered propellant grains to achieve this goal. The difficulties in
producing such kind of propellants can now be bypassed thanks to 3D printers. Our approach
consists in deposing a viscous energetic paste, containing a solvent, with an adapted machine.
The layer formation and the adhesion between them are investigated in this work.",,,,,,
"['Pegues, Jonathan', 'Roach, Michael', 'Shamsaei, Nima']",2021-11-18T00:29:49Z,2021-11-18T00:29:49Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90371', 'http://dx.doi.org/10.26153/tsw/17292']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'crack nucleation', 'twin boundary', 'heat treatment']",Additive Manufacturing of Fatigue Resistant Materials: Avoiding the Early Life Crack Initiation Mechanisms During Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6601581c-bb73-4eb9-9ccf-c6ab4924a19b/download,University of Texas at Austin,"The full potential of additive manufacturing (AM) has been limited by the process induced
defects within the fabricated materials. Defects such as lack of fusions and gas entrapped pores act
as stress concentrators and result in premature fatigue crack initiation, severely limiting the
applicability of AM in fatigue-critical applications. However, by understanding the failure
mechanisms associated with AM materials and leveraging the intimate localized thermal input (i.e.
process conditions), the failure mechanisms for some materials may be avoided during the
fabrication process. This study investigates the crack initiation behavior of an AM austenitic
stainless steels subjected to fatigue testing. The microstructural features responsible for fatigue
crack initiation are captured at the surface by ex-situ electron backscatter diffraction. Results show
that the higher cooling rates during AM offer the opportunity to fabricate fatigue resistant
austenitic stainless steel parts by avoiding the microstructural features that are most detrimental to
fatigue performance.",,,,,,
"['Kishore, Vidya', 'Chen, Xun', 'Ajinjeru, Christine', 'Hassen, Ahmed Arabi', 'Lindahl, John', 'Failla, Jordan', 'Kunc, Vlastimil', 'Duty, Chad']",2021-10-27T23:24:26Z,2021-10-27T23:24:26Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89642,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['semi-crystalline thermoplastics', 'PPS', 'PEKK', 'additive manufacturing']",Additive Manufacturing of High Performance Semicrystalline Thermoplastics and Their Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/053177a7-2704-437e-b926-a1e66dd7731b/download,University of Texas at Austin,"This work investigates the use of two semi-crystalline high performance
thermoplastics, polyphenylene sulfide (PPS) and poly (ether ketone ketone) (PEKK), as
feedstock for fused filament fabrication process. Composites of PPS and PEKK are emerging
as viable candidates for several components in aerospace and tooling industries and additive
manufacturing of these materials can be extremely beneficial to lower manufacturing costs and
lead times. However, these materials pose several challenges for extrusion and deposition due
to some of their inherent properties as well as thermal and oxidative responses. To better
understand the properties of such systems specific to 3D printing and determine the critical
parameters that make them “printable”, various rheological and thermal properties have been
studied for neat as well as short fiber reinforced PPS and PEKK systems. Attempts were also
made to print these materials in a customized high temperature fused filament fabrication
system.",,,,,,
"['Wasley, T.', 'Li, J.', 'Ta, D.', 'Shephard, J.', 'Stringer, J.', 'Smith, P.', 'Esenturk, E.', 'Connaughton, C.', 'Kay, R.']",2021-10-28T22:24:18Z,2021-10-28T22:24:18Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89718,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'process integration', 'multilayer embedded electronics', 'DLP stereolithography', 'material dispensing', 'flip chip packaging']",Additive Manufacturing of High Resolution Embedded Electronic Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f61a9f4-3b44-4556-a47c-163d5ac2a159/download,University of Texas at Austin,"Additive Manufacturing (AM) processes can facilitate the rapid iterative product
development of electronic devices by optimising their design and functionality. This has been
achieved by combining two additive manufacturing processes with conventional surface mount
assembly to generate high resolution embedded multilayer electronic circuits contained within a
3D printed polymer part. Bottom-up DLP Stereolithography and material dispensing of isotropic
conductive adhesives have been interleaved to deposit microscale features on photopolymer
substrates. The material dispensing process has demonstrated the high density deposition of
conductors attaining track widths of 134µm and produced interconnects suitable for directly
attaching bare silicon die straight to the substrate. Interconnects down to a diameter of 149µm at
a pitch of 457µm have been realized. In addition, this research developed a novel method for
producing high aspect ratio z-axis connections. These were simultaneously printed with the
circuit and component interconnects by depositing through-layer pillars with a maximum aspect
ratio of 3.81. Finally, a method to accurately embed the packaged circuit layer within the printed
part has been employed using bottom-up stereolithography.",,,,,,
"['Cui, Wenyuan', 'Zhang, Xinchang', 'Liou, Frank']",2021-11-02T19:27:08Z,2021-11-02T19:27:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89874,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'high-entropy alloys', 'microstructures', 'mechanical properties']",Additive Manufacturing of High-Entropy Alloys - A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d710c88e-1341-4b52-8821-a0591387b3db/download,University of Texas at Austin,"High-entropy alloys have attracted increasingly interest due to their unique compositions,
microstructures and mechanical properties. Additive manufacturing has been recognized as a
promising technology to fabricate the high-entropy alloys in the recent years. The purpose of this
paper is to review the current research progress in high-entropy alloys by additive manufacturing
process. It will first highlight the important theory of the high-entropy alloys. The next aspect is
to summarize current additive manufacturing methods applied for the high entropy alloys. At last,
the correlation between the microstructures and the mechanical properties of the high-entropy
alloys will be examined and discussed.",,,,,,
"Basak, Amrita",2021-11-18T00:34:01Z,2021-11-18T00:34:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90372', 'http://dx.doi.org/10.26153/tsw/17293']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"[""high-ℽ' nickel-based superalloys"", 'additive manufacturing', 'selective laser melting', 'SLM', 'processing', 'microstructure', 'mechanical properties']",Additive Manufacturing of High-Gamma Prime Nickel-Based Superalloys through Selective Laser Melting (SLM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/766c204a-2eeb-4098-a48a-f8b33cbb492d/download,University of Texas at Austin,"High-ℽ' nickel-based superalloys are abundantly used in the aerospace, marine, nuclear,
and chemical industries where excellent corrosion and oxidation resistance, superior mechanical
properties, and exceptional high-temperature performance are required. However, selective laser
melting (SLM)-based additive manufacturing (AM) of high-ℽ' nickel-based superalloys pose
significant challenges due to these alloys’ complex chemistry. With multiple alloying elements
and high aluminum + titanium fraction, these materials when consolidated through SLM form
various secondary phases severely affecting the processability leading to the formation of cracks.
The objective of this review is to summarize the progress made so far on SLM of high-ℽ' nickel-based superalloys with a special emphasis towards elucidating the relationships between
processing, microstructures, and properties in this alloy system.",,,,,,
"['Platt, S.', 'Schnell, N.', 'Witt, G.', 'Kleszczynski, S.']",2024-03-27T03:31:38Z,2024-03-27T03:31:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124467', 'https://doi.org/10.26153/tsw/51075']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'additive manufacturing', 'metal', 'sandwich sheets']",Additive manufacturing of hybrid sandwich sheets by laser powder bed fusion of metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1eb07f93-e335-482c-a1bc-271f45ea5d9f/download,University of Texas at Austin,"In the context of lightweight applications, laser powder bed fusion of metals allows the
creation of high-complexity structures at minimal use of material. Traditional elements of
lightweight construction are sandwich sheets, which comprise two cover sheets with a fine core
structure joined in the centre. Thus, these lightweight elements contain both geometrically
simple (cover sheets) and geometrically complex (core structure) elements. Conventional
manufacturing of core structures is limited in terms of geometrical freedom. On the other hand,
Additive Manufacturing of sheets has disadvantages in terms of economic efficiency.
Therefore, a combined process consisting of additive and conventional cost-efficient
manufacturing is proposed to eliminate both disadvantages. This publication presents a hybrid
manufacturing route to produce metal sandwich sheets. The hybrid sandwich sheets are
manufactured using a rolled cover sheet as a base plate and additive manufactured core
structures including an upper cover sheet. For this purpose, a recently developed sheet mounting
system for implementation in a laser powder bed fusion process is presented and evaluated
concerning manufacturing criteria such as process stability and dimensional accuracy of the
final components.",,,,,,
"['Ho, Jason', 'Lough, Cody S.', 'Mulligan, Phillip', 'Kinzel, Edward C.', 'Johnson, Catherine E.']",2021-11-09T18:54:44Z,2021-11-09T18:54:44Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90117', 'http://dx.doi.org/10.26153/tsw/17038']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['shaped charge', 'liners', 'geometries', 'SS 304L', 'selective laser melting', 'additive manufacturing']",Additive Manufacturing of Liners for Shaped Charges,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a797230-2ced-40d8-909d-8c8ea4428ccc/download,University of Texas at Austin,"A Shaped Charge (SC) is an explosive device used to focus a detonation in a desired
direction, and has applications in demolition and oil extraction. The focusing relies on a void in
the explosive mass, shaped by a metal liner that becomes a projectile during detonation. Additive
Manufacturing (AM) allows greater design freedom and geometric complexity for the liner portion
of the SC. Specifically, hierarchical structuring and functional grading can potentially provide
greater velocity, directionality, and efficiency. In this work, Selective Laser Melting (SLM) is used
to explore different geometries for an SC liner made out of SS 304L. These are detonated using
the explosive Composition C-4 to evaluate performance metrics, depth and standoff, and are
observed using high-speed imaging. The work shows the potential for advanced shaped charges
produced using SLM.",,,,,,
"['Grothaus, Bradley', 'Huck, Dane', 'Sutton, Austin']",2021-11-09T19:04:37Z,2021-11-09T19:04:37Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90126', 'http://dx.doi.org/10.26153/tsw/17047']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['bandpass filters', '304L', 'stainless steel', 'overhangs', 'radar receivers', 'selective laser melting', 'additive manufacturing']",Additive Manufacturing of Metal Bandpass Filters for Future Radar Receivers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/974faf79-8274-404f-a250-e3e6d394639a/download,University of Texas at Austin,"Selective laser melting (SLM) is a powder-bed fusion (PBF) process that bonds successive layers
of powder with a laser to create components directly from computer-aided design (CAD) files. The
additive nature of the SLM process in addition to the use of fine powders facilitates the
construction of complex geometries, which has captured the attention of those involved in the
design of bandpass filters for radar applications. However, a significant drawback of SLM is its
difficulty in fabricating parts with overhangs necessitating the use of support structures, which, if
not removed, can greatly impact the performance of bandpass filters. Therefore, in this study
bandpass filters are manufactured in two stages with 304L stainless steel where each builds only a
portion of the part to improve the reliability in manufacturing the overhangs present. The results
show that the versatility of SLM can produce difficult-to-manufacture bandpass filters with high
dimensional accuracy.","This work was funded by Honeywell Federal Manufacturing &
Technologies under Contract No. DE-NA0002839 with the U.S. Department of Energy.",,,,,
"['Chen, Yitao', 'Liou, Frank']",2021-11-10T22:52:02Z,2021-11-10T22:52:02Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90199', 'http://dx.doi.org/10.26153/tsw/17120']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'functionally graded materials', 'mechanical properties', 'laser metal deposition', 'selective laser melting']",Additive Manufacturing of Metal Functionally Graded Materials: A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67e039e0-cf31-4dfe-9a1a-ad579c68cae9/download,University of Texas at Austin,"Functionally graded materials (FGMs) have attracted a lot of research interest due to their
gradual variation in material properties that result from the non-homogeneous composition or
structure. Metal FGMs have been widely researched in recent years, and additive manufacturing
has become one of the most important approaches to fabricate metal FGMs. The aim of this paper
is to review the research progress in metal FGMs by additive manufacturing. It will first introduce
the unique properties and the advantages of FGMs. Then, typical recent findings in research and
development of two major types of metal additive manufacturing methods, namely laser metal
deposition (LMD) and selective laser melting (SLM), for manufacturing different types of metal
FGMs will be discussed. Finally, the major technical concerns in additive manufacturing of metal
FGMs which are closely related to mechanical properties, and industrial applications of metal
FGMs will be covered.",,,,,,
"['Yang, Seongun', 'Xu, Donghua', 'Yan, Dongqing', 'Albert, Marc', 'Pasebani, Somayeh']",2024-03-26T23:04:04Z,2024-03-26T23:04:04Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124440', 'https://doi.org/10.26153/tsw/51048']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser directed energy deposition', 'oxide dispersion strengthened alloy', '316L stainless steel']",Additive Manufacturing of ODS Steels Using Powder Feedstock Atomized with Elemental Yttrium,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa619bf3-45b6-446d-9705-74a37404ca1b/download,University of Texas at Austin,"This study investigates the microstructure and mechanical properties of an austenitic ODS steel produced
by the Laser Directed Energy Deposition (LDED) process using powder feedstock atomized with
elemental yttrium. The Microstructure of the samples was characterized by electron microscopy, and mechanical
properties were measured using a tensile test and nanoindentation. Further, the thermal stability of the LDEDproduced ODS steels were evaluated. As-printed samples showed a cellular structure with Si-Mn-Y-Oenriched nanoparticles that were found to be amorphous. After 100 hours at 1000°C in an argon atmosphere, a
partially recrystallized microstructure with a decrease in the number density of Y-O-enriched nanoparticles
with crystalline structure was revealed. The as-printed (600 W, 600 mm/min) samples exhibited an ultimate
tensile strength of 774 MPa and an elongation at a break of 22%. A lower ultimate tensile strength of 592 MPa
and higher elongation of 42% was measured after 100 hours at 1000°C.",,,,,,
"['Yuan, Mengqi', 'Bourell, David']",2021-10-18T20:17:38Z,2021-10-18T20:17:38Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89230,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser sintered polyamide 12', 'lithophane', 'optical properties']",Additive Manufacturing of Optically Translucent Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/333d3f68-3030-401f-9473-f81556b9ad06/download,University of Texas at Austin,"A lithophane is a translucent image created by varying the plate thickness; the image is
observed using a back lit light source. Additive manufacturing makes highly complex
lithophane fabrication possible. Optical properties of laser sintered polyamide (PA) 12
translucent additive manufactured parts were analyzed and applied to the lithophane fabrication.
Several parameters affecting lithophane manufacturing performance are discussed including
brightness and contrast versus plate thickness and grayscale level, surface finish quality and
manufacturing orientation. Moreover, other thermoplastic semi-crystalline materials were
analyzed for LS optically translucent part production. Plates and lithophanes were built using a
different AM platform: stereolithography (SL) with Somos® ProtoGen™ O- XT 18420 white
resin. Different optical properties and lithophane performance were observed and compared
with PA 12 parts.
It was found laser sintered polyamide 12 optical properties varied with light wavelength
and reached maximum transmission under green light. When building in the XY plane, thin
layer thickness and large maximum plate thickness led to higher contrast and gray scale level.
Lithophane quality was largely improved when fabricated in the ZX/ZY plane orientation.
Lithophanes made from SL were analyzed but showed lower contrast due to the optical
property characteristics of the white resin.",,,,,,
"['Claybrook, F.R.', 'Southee, D.J.', 'Mohammed, M.I.']",2024-03-27T03:33:53Z,2024-03-27T03:33:53Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124468', 'https://doi.org/10.26153/tsw/51076']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'diabetic foot insoles', 'diabetes']",ADDITIVE MANUFACTURING OF PERSON SPECIFIC DIABETIC FOOT INSOLES WITH ADJUSTABLE CUSHIONING PROPERTIES USING TPMS LATTICE STRUCTURES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ceed04fa-3dda-4d6c-883a-9fba1cfa5639/download,University of Texas at Austin,"Complications associated with diabetes are numerous, including foot problems which in
extreme cases can lead to amputations. Current management involves the use of foam diabetic
foot insoles (DFI) to provide cushioning, however load bearing capacity is limited, and designs
often do not provide a comfortable or efficacious fit. This study aspires to resolve problems
using digital fabrication workflows. The exploration of potential 3D scanning of anatomical
data, parametric modelling, and additive manufacturing was created for a patient specific DFI.
This demonstrated that patient scanning data provides means to create a custom fitting insole
template, improving overall fit. Demonstrating the use of triply periodic minimal surface
(TPMS) structures, fabricated in Thermoplastic Polyurethane (TPU), as cushioning structures,
whereby unique lattice designs allow regionally tailored mechanical loading properties of the
insole concept. The final insole realises a superior alternative to tradition DFI.",,,,,,
"['Radyjowski, P.P.', 'Bourell, D.L.', 'Kovar, D.', 'Ellzey, J.L.']",2021-12-01T21:46:51Z,2021-12-01T21:46:51Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90625', 'http://dx.doi.org/10.26153/tsw/17544']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['cermets', 'Si-SiC', 'combustion', 'combustor', 'additive manufacturing']",Additive Manufacturing of Si-SiC Cermets for Combustion Device Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/35d6eee5-c128-48f9-bf85-9cd163494716/download,University of Texas at Austin,"Traditional manufacturing methods for high-temperature devices are time intensive and
limited to simple shapes. Additive manufacturing (AM) reduces lead times and opens the design
space to more complex geometries. Indirect laser sintering of siliconized silicon carbide (Si-SiC)
cermets was evaluated for creating devices compatible with combustion environments. Heat
recirculating combustors especially benefit from geometric flexibility. Si-SiC process
improvements are presented for the production of cermet combustors. The effect of flame on the
material was studied by directly exposing samples to hot combustion products at 1000°C and
1260°C for 10 hours. Subsequently, three experimental Si-SiC combustors were manufactured and
fired to evaluate the practical aspects of cermet applications. Each device was operated for 70
hours under excess-air methane flames with solid temperatures up to 1405°C. The surface
oxidation and phase changes were assessed. Operating temperatures between 1200°C and 1350°C
reduce damage to the material and give a promise of long-term, high-temperature operation.",,,,,,
"['Saari, M.', 'Galla, M.', 'Cox, B.', 'Krueger, P.', 'Cohen, A.', 'Richer, E.']",2021-10-21T15:17:08Z,2021-10-21T15:17:08Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89392,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['thermoplastic elastomers', '3D printing', 'soft parts', 'composite parts', 'feed extrusion']",Additive Manufacturing of Soft and Composite Parts from Thermoplastic Elastomers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/139a155e-64ae-420f-98bd-107c67b4dcf1/download,University of Texas at Austin,"Thermoplastic elastomers (TPEs) are low-durometer materials that can support large
strains without breaking, making them attractive materials for producing 3-D printed soft
components. However, prefabricated TPE filament, especially those with low hardness, cannot
be used in typical filament feed extrusion mechanisms that are popular in material extrusion-based 3-D printers today.
 Therefore, we have developed a mini-screw extruder, small enough to be incorporated on
a typical 3-D printer system, and capable of extruding various TPE formulations directly from
commercially available pellets. This paper presents the design and thermal analysis of the mini-extruder, experimental testing of the 3-D printing process for TPEs with nominal hardness in the
range of 5 – 52 Shore A, and compression and tension tests of the properties of printed parts. By
combining 3-D printing of soft TPEs with rigid thermoplastics, the new system also opens up
new possibilities in additive manufacturing of soft and hard composite parts.",,,,,,
"['Clymer, Daniel', 'Beuth, Jack', 'Cagan, Jonathan']",2021-11-01T20:48:43Z,2021-11-01T20:48:43Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89744,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['process design', 'process outcomes', 'metal-based additive manufacturing', 'additive manufacturing']",Additive Manufacturing Process Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac4c72e3-d199-483b-9062-8840e646a571/download,University of Texas at Austin,"A current issue in metal-based additive manufacturing (AM) is achieving consistent,
desired process outcomes in manufactured parts. When process outcomes such as strength,
density, or precision need to meet certain specifications, these specifications can be met by
changes in process variable selection. However, the changes required to achieve a better part
performance may not be intuitive, particularly because process variable changes can
simultaneously improve some outcomes while decreasing others. In this work, the tradeoffs
between multiple process outcomes are formalized and the design problem is explored
throughout the design space of process variables. User input for each process outcome is
considered and the best combination of process variables is found to achieve a user’s desired
outcome.",,,,,,
"['Moylan, Shawn', 'Land, Joshua', 'Possolo, Antonio']",2021-10-21T19:50:55Z,2021-10-21T19:50:55Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89434,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'round robin studies', '3D printers', 'geometric performance']",Additive Manufacturing Round Robin Protocols: A Pilot Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/949b4f41-9aa1-4e15-acc5-35eb0babeeff/download,University of Texas at Austin,"As the number of users of additive manufacturing (AM) steadily increases, and
considering their demand for material and process specifications, the need for standard protocols
for round robin studies is increasing accordingly. Researchers at the National Institute of
Standards and Technology (NIST) have conducted and participated in several AM round robin
studies with the aim not only to characterize the AM process, and material but also to improve
the understanding of AM round robin studies themselves. One simple study, a pilot round robin
study investigating geometric performance of NIST-owned consumer-grade 3D printers,
provides excellent examples of typical results and lessons learned. While individual printers
produced relatively consistent results, there was significant variability between the printers. This
variability existed despite best efforts to ensure participants followed consistent procedures in
building the test parts. Further, the variability made it apparent that collecting pedigree data
from each build was required to draw any conclusions about potential causes of the variability.",,,,,,
"['Porter, Daniel A.', 'Cohen, Adam L.', 'Krueger, Paul S.', 'Son, David']",2021-11-04T15:06:54Z,2021-11-04T15:06:54Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89981', 'http://dx.doi.org/10.26153/tsw/16902']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['stock ultraviolet curable silicone', 'stock UV curable silicone', '3D printing', 'extrude and cure additive manufacturing', 'ECAM']",Additive Manufacturing Utilizing Stock Ultraviolet Curable Silicone,Conference paper,https://repositories.lib.utexas.edu//bitstreams/277c930b-1308-4c06-8cb7-1ea667fa04de/download,University of Texas at Austin,"Extrude and Cure Additive Manufacturing (ECAM) is a method that enables 3D printing
(3DP) of common thermoset materials. Ultraviolet (UV)-curable silicone is an example of a
thermoset material with a large number of industrial and medical applications. 3D printed silicone
prototype parts are obtained using a custom high pressure ram, valve, and UV exposure system.
This paper will address issues with printing stock UV curable silicone such as electrostatic
repulsion, in-nozzle curing, and extrudate slumping. One solution that addresses two issues is
adding carbon black (CB) to the mixture to reduce electrostatic repulsion while also inhibiting UV
cure depth, hence preventing material from curing in the nozzle. Evidence shows that too much
carbon black can be detrimental to the structural stiffness of the resulting part.",,,,,,
"['Yigit, Ismail Enes', 'Isa, Mohammed', 'Lazoglu, Ismail']",2021-11-15T22:04:07Z,2021-11-15T22:04:07Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90287', 'http://dx.doi.org/10.26153/tsw/17208']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['support structures', 'modular', 'additive manufacturing', 'robotic']",Additive Manufacturing with Modular Support Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4274732c-1b94-4413-bdb6-3e516dabc4c3/download,University of Texas at Austin,"Additive manufacturing is praised to have low material waste compared to conventional
subtractive manufacturing methods. This is not always the case when the computer aided design
(CAD) model consists of large overhangs. In such cases, fabrication of support structures are
required to fill the space between the CAD model and the manufacturing bed. In post processing,
these support structures must be removed from the model. These supports become waste and reduce
the buy-to-fly ratio. In this paper, we present a pre-fabricated reusable modular support structure
system which minimizes the fabrication of conventional support structures. The conventional
supports are replaced with modular support blocks wherever possible. The blocks are stacked under
the overhang with a robot arm until the overhang of the model is reached. Conventional supports
can be fabricated on top when needed with fused filament fabrication. This strategy reduces
fabrication of conventional supports. Thus, faster fabrication times are obtained with higher buy-to-fly ratios.",,,,,,
"['Romero, L.', 'Guerrero, A.', 'Espinosa, M.M.', 'Jiménez, M.', 'Domínguez, I.A.', 'Domínguez, M.']",2021-10-12T20:37:49Z,2021-10-12T20:37:49Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88735', 'http://dx.doi.org/10.26153/tsw/15669']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['RepRap', '3D printer', 'open source rapid prototying', 'rapid prototyping', 'additive manufacturing']",Additive Manufacturing with RepRap Methodology: Current Situation and Future Prospects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6b179cb-2d4b-4e0f-b0e8-b9f9e16f3b0d/download,University of Texas at Austin,"In February 2004, Adrian Bowyer, from the University of Bath, began an open initiative
called RepRap, with the purpose of creating an open source rapid prototyping machine
which, moreover, could replicate itself. This article analyzes the current status of the
RepRap initiative, commenting the basic components of RepRap machines, the
differences between the different 3D printers developed by the RepRap community so
far, and the technical possibilities that opens this technology from the engineering point
of view. In addition we propose some improvements that could be perfectly feasible in
the short term. For this purpose, the assembly of a RepRap Mendel Prusa was
performed, but with some modifications.",,,,,,
"['Chen, Yong', 'Zhou, Chi', 'Luo, Jingyuan']",2021-09-30T13:13:31Z,2021-09-30T13:13:31Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88228', 'http://dx.doi.org/10.26153/tsw/15169']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '5-axis SFF', 'CNC accumulation', 'build around inserts']",Additive Manufacturing without Layers: A New Solid Freeform Fabrication Process based on CNC Accumulation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d201dda-a4e9-40f2-9bb2-c19d3d1aea3a/download,University of Texas at Austin,"Most current additive manufacturing processes are layer-based, that is building a physical model
layer-by-layer. By converting 3-dimensional geometry into 2-dimensional contours, the layer-based
approach can dramatically simplify the process planning steps. However, there are also drawbacks
associated with the layer-based approach such as inconsistent material properties between various
directions. In a recent NSF workshop on additive manufacturing, it is suggested to investigate alternative
non-layer based approaches. In this paper, we present an additive manufacturing process without planar
layers. In the developed testbed, an additive tool based on a fiber optics cable and a UV-LED has been
developed. By merging such tools inside a liquid resin tank, we demonstrate its capability of building
various 2D and 3D structures. The technical challenges related to the development of such a process are
discussed. Some potential applications including part repairing and building around inserts have also
been demonstrated.",,,,,,
"Diewald, Evan P.",2021-12-01T22:11:49Z,2021-12-01T22:11:49Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90634', 'http://dx.doi.org/10.26153/tsw/17553']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive OS', 'open-source platform', 'data management', 'IP protection', 'AM data']",Additive OS: An Open-Source Platform for Additive Manufacturing Data Management & IP Protection,Conference paper,https://repositories.lib.utexas.edu//bitstreams/16cff5b7-663e-4109-8638-33cbe64335d7/download,University of Texas at Austin,"The additive manufacturing (AM) digital thread presents unique challenges for data management
and security. While proprietary software packages solve many issues, they can be expensive and
lacking in customization. Additive OS is an open-source platform for importing, sharing,
organizing, and querying AM data. Man-in-the-middle attacks, secure print licensing, and IP theft
are addressed using custom smart contracts, ontology is preserved with a NoSQL database and
directed acyclic graph (DAG) representations, and peer-to-peer content delivery facilitates low-latency file transfer. The application includes a browser-based graphical user interface, but
developers can access the underlying API to invoke sophisticated queries, add functionality, or run
the lightweight client on low-resource hardware.",,,,,,
"['Frank, Matthew C.', 'Peters, Frank E.', 'Karthikeyan, Rajesh']",2021-09-30T14:17:24Z,2021-09-30T14:17:24Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88254', 'http://dx.doi.org/10.26153/tsw/15195']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Rapid Pattern Manufacturing', 'additive techniques', 'subtractive techniques', 'injection mold tooling', 'seam-free laminated aluminum', 'casting patterns']",Additive/Subtractive Rapid Pattern Manufacturing for Casting Patterns and Injection Mold Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a4dfef5-1b9e-4d57-8c3b-360aa6c27eb6/download,University of Texas at Austin,"This paper presents a Rapid Pattern Manufacturing system that involves both additive and
subtractive techniques whereby slabs are sequentially bonded and milled using layered toolpaths.
Patterns are grown in a bottom-up fashion, both eliminating the need for multi-axis operations and
allowing small features in deep cavities. Similar approaches exist in the literature; however, this system
is able to provide a larger range of both materials and sizes, from smaller conventional injection mold
tooling to very large wood or urethane sand casting patterns. This method introduces a novel sacrificial
support structure approach by integrating a flask into the pattern build process. The system has been
implemented in an automated machine capable of producing patterns in excess of several thousand
pounds in a build envelope over 1m3. In this current research, a new layer bonding method using friction
stir welding of aluminum plates is presented. In this manner, one can create seam-free laminated
aluminum injection mold tooling using a unique combination of industrial adhesives and friction stir spot
welding to secure the slab initially, then continuous friction stir welding of layer perimeters that are
subsequently machined in a layer-wise process.",,,,,,
"['Lee, Seungjong', 'Ghiaasiaan, Reza', 'Shao, Shuai', 'Gradl, Paul R.', 'Shamsaei, Nima']",2023-01-25T13:52:26Z,2023-01-25T13:52:26Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117285', 'http://dx.doi.org/10.26153/tsw/44166']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['316L stainless steel', 'Laser powder directed energy deposition', 'Heat treatment', 'Microstructure', 'Tensile properties']",Additively Manufactured 316L Stainless Steel: Effect of Heat Treatment on Microstructure and Tensile Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0bc49a77-f38c-418a-ae13-c5d73326453b/download,,"The microstructure and tensile properties of 316L stainless steel (SS) fabricated using the 
laser powder directed energy deposition (LP-DED) after various heat treatment (HT) steps such as 
stress-relief (SR), solution annealing (SA), and hot isostatic pressing (HIP) are characterized. 
Microstructures before and after HTs are analyzed using both optical and scanning electron 
microscopy (SEM). Both quasi-static uniaxial tensile and hardness tests are performed to measure 
mechanical properties. The tensile results indicate that the non-heat treated (NHT) condition 
possesses higher strengths but lower ductility as compared to the other HT conditions (i.e., SR, 
SA, HIP, SR+SA, and SR+HIP). By employing the two-step HT conditions (i.e., SR+SA and 
SR+HIP), no significant changes on tensile properties as compared to the individual single-step 
HT conditions (i.e., SA or HIP) are observed. The findings suggest that two-step HTs are not 
required for LP-DED 316L SS unless HIP is needed to minimize volumetric defect contents.",,,,,,
"['Debeau, D.A.', 'Seepersad, C.C.']",2021-11-04T19:37:30Z,2021-11-04T19:37:30Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90012', 'http://dx.doi.org/10.26153/16933']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['static mechanical performance', 'dynamic mechanical performance', 'honeycomb structures', 'conformal negative stiffness', 'additive manufacturing']",Additively Manufactured Conformal Negative Stiffness Honeycombs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fd8c96ba-b35d-44e4-893b-58f807f184ef/download,University of Texas at Austin,"This study investigates the static and dynamic mechanical performance of conformal
negative stiffness honeycomb structures. Negative stiffness honeycombs are capable of
elastically absorbing a static or dynamic mechanical load at a predefined force threshold and
returning to their initial configuration after the load is released. Most negative stiffness
honeycombs rely on mechanical loading that is orthogonal to the base of the structure. In this
study, a more three dimensional design is presented that allows the honeycomb to conform to
complex surfaces and protect against impacts from multiple directions. The conformal designs
are additively manufactured in nylon and stainless steel and subjected to quasi-static mechanical
loading and dynamic mechanical impact tests that demonstrate their impact protection
capabilities.",,,,,,
"['Dressler, Amber', 'Scharnberg, William', 'Abousleiman, Anthony', 'Harris, Samantha', 'New, Phil']",2021-10-28T22:10:06Z,2021-10-28T22:10:06Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89714,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fasteners', 'additive manufacturing', 'build-to-build', 'selective laser sintering']",Additively Manufactured Fasteners,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a06d840c-6e88-4b1b-8cbf-c2008b514e01/download,University of Texas at Austin,"Additive manufacturing (AM) has reached a critical point which enables production of
complex, high resolution, custom parts from robust materials. However, traditional fasteners are
still use to join these complex parts together. Integrating fasteners into additively manufactured
parts is beneficial for part production but there is uncertainty in their design. To understand how
the fasteners fit and function, mechanical property data was collected on the prototypes. This
data along with insights gained while building and testing the prototypes increased the
knowledge base of design for additive manufacturing and build-to-build variability in selective
laser sintering (SLS).",,,,,,
"['Slightam, Jonathon E.', 'Gervasi, Vito R.']",2021-10-11T22:44:26Z,2021-10-11T22:44:26Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88673', 'http://dx.doi.org/10.26153/tsw/15607']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additively manufactured flexible fluidic actuators', 'Selective Laser Sintered Nylon 12', 'novel fluid power actuators', 'Magnetic Resonance Imaging', 'surgery', 'rehabilitation']",Additively Manufactured Flexible Fluidic Actuators For Precision Control in Surgical Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ce03f338-c232-421b-b86b-249750b14ad1/download,University of Texas at Austin,"Previously, the Milwaukee School of Engineering (MSOE) demonstrated a dexterous
tele-operational robotic system where actuators, joints, and linkages were fabricated
simultaneously using Selective Laser Sintered Nylon 12. Primary motivation for this research
was to conceive novel fluid power actuators that were inherently safe, compact, and Magnetic
Resonance Imaging (MRI) compatible for surgery and rehabilitation. Although the concept of
fabricating MRI compatible fluid power devices was demonstrated, further proof of precision
control was needed. The design and implementation of additively manufactured flexible fluidic
actuators (AMFFA) for precision control, best practices, and the comparison of these actuators
with other actuation technologies are presented.",,,,,,
"['Muhammad, Muztahid', 'Ghiaasiaan, Reza', 'Gradl, Paul R.', 'Schobel, Andre', 'Godfrey, Donald', 'Shao, Shuai', 'Shamsaei, Nima']",2021-12-06T22:20:58Z,2021-12-06T22:20:58Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90696', 'http://dx.doi.org/10.26153/tsw/17615']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Hastelloy-X', 'microstructure', 'grain size', 'macrohardness']",Additively Manufactured Hastelloy-X: Effect of Post-Process Heat Treatment on Microstructure and Mechanical Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cad11fb7-0fd2-481a-a985-b9cf0c0861f3/download,University of Texas at Austin,"In this study, the effect of post-process heat treatment on the microstructure and
mechanical properties of Hastelloy-X superalloy fabricated via two different additive
manufacturing technologies, namely, laser beam powder bed fusion (LB-PBF) and laser
powder directed energy deposition (LP-DED), is investigated. Microstructure was
examined using scanning electron microscopy (SEM) and electron backscattered
diffraction (EBSD) analysis, while mechanical properties were evaluated by macro-hardness testing using the Rockwell B method. Microstructure of the alloys was studied
thoroughly after several heat treatments that involve stress-relieving (at 1066°C for 1.5
hours), hot isostatic pressing (HIP at 1163°C for 3 hours under 103 MPa pressure), and/or
solution treatment (at 1177°C for 3 hours). The results revealed that, for both LB-PBF and
LP-DED Hastelloy-X, the post-process heat treatments resulted in uniform grain structure
as well as partial dissolution of carbides, although they have different grain sizes.",,,,,,
"['Muhammad, Muztahid', 'Ghiaasiaan, Reza', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2021-12-06T22:23:59Z,2021-12-06T22:23:59Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90697', 'http://dx.doi.org/10.26153/tsw/17616']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder directed energy deposition', 'Haynes 230', 'microstructure', 'tensile behavior']",Additively Manufactured Haynes 230 by Laser Powder Directed Energy Deposition (LP-DED): Effect of Heat Treatment on Microstructure and Tensile Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/622f2ad6-a83d-4f30-b043-383e4e240f31/download,University of Texas at Austin,"The microstructure and tensile mechanical properties of Haynes 230 fabricated
through laser powder directed energy deposition (LP-DED) were investigated, varying
temperature heat treatments between 900°C to 1177°C following deposition. Scanning
electron microscopy (SEM) was employed for microstructural analysis, whilst tensile testing
was utilized to evaluate the room temperature mechanical properties of the alloy. In an as-deposited state, the initial microstructure consisted of cellular γ and M6C/M23C6 carbides. The
cellular regions seem to be fully dissolved upon solutionizing at 1177°C for 3 hours. Following
post-deposition heat-treatments, the carbides were observed to precipitate and grow along
the grain boundaries as well as in the interior of grains. Solutionizing at 1177°C for 3 hours
following stress-relieving yielded better ductility and had an insignificant effect on the
strength.",,,,,,
"['Zak, Gene', 'Wang, Wendy Xu']",2019-10-24T18:33:42Z,2019-10-24T18:33:42Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77423', 'http://dx.doi.org/10.26153/tsw/4512']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Adhesive Bonding,Adhesive Bonding of Sheet for Laminated Metal Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/779d4eea-4f48-4402-8f71-faf858d18c14/download,,"There exists a significant body of work on metal laminate tooling built by the “cut-stack-bond”
approach; however, automation with this method is difficult. Building laminations by ""stack-bond-cut""
sequence, on the other hand, is more amenable to automation. Two main challenges of ""stack-bond-cut""
sequence are blind contour cutting and bonding of the sheet. In this study, we investigate the hot-roller
method of thermoplastic adhesive bonding for the metal laminations. Metal sheet, having thermal
characteristics significantly different from paper, poses its own specific problems. During the bonding
process, in order to achieve good bond strength, appropriate heat and pressure must be applied. As the
stack builds up, thermal and mechanical properties change. This inconsistency of process conditions can
potentially lead to part warpage, unless carefully controlled. Temperature measurements with a
thermocouple embedded into lamination stack showed the effect of bonding process parameters on the
laminate temperature.","We gratefully acknowledge the financial support of Centre for Automotive Materials and
Manufacturing, Ontario Innovation Trust, and Canada Foundation for Innovation.",,,,,
"['Utela, Ben', 'Anderson, Rhonda L.', 'Kuhn, Howard']",2020-02-28T16:30:17Z,2020-02-28T16:30:17Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80117', 'http://dx.doi.org/10.26153/tsw/7138']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Three-Dimensional Printing,Advanced Ceramic Materials and Processes for Three-Dimensional Printing (3DP),Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1e6819c-8031-4e53-8535-c0c9d4e002c9/download,,"The University of Washington and ExOne, Inc. are collaborating in the
development of advanced ceramic materials and processes for three-dimensional printing
(3DP). The focus of the research to be presented is work funded by the National Science
Foundation to develop a biocompatible alumina-based system for medical and dental
applications. Materials design, characterization, and processing considerations will be
discussed.",,,,,,
"['Lyons, Alan', 'Krishnan, Shankar', 'Mullins, John', 'Hodes, Marc', 'Hernon, Domhnaill']",2021-09-29T18:17:14Z,2021-09-29T18:17:14Z,2009,Mechanical Engineering,,"['https://hdl.handle.net/2152/88207', 'http://dx.doi.org/10.26153/tsw/15148']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['heat sinks', 'heat sink designs', 'three-dimensional printing', 'monolithic copper structures']",Advanced Heat Sinks Enabled by Three-Dimensional Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e6ba00c-afce-483f-a4e1-db50217237a8/download,University of Texas at Austin,"With the rapid rise in power dissipated by integrated circuits, improved heat sinks designs
are needed to decrease the thermal resistance between them and forced air streams.
Manufacturing methods such as extrusion, machining and die-casting have been used to fabricate
conventional longitudinal fin designs. Although these technologies add relatively little cost, they
preclude the fabrication of more complex heat sink designs. We discuss novel heat sink designs
which increase surface area and/or modulate air flow streams. Fabrication of these
unconventional designs is enabled by using 3D printing technologies with the subsequent
conversion of the printed parts into monolithic copper structures by investment casting.",,,,,,
"['Weisensel, L.', 'Travitzky, N.', 'Greil, P.']",2020-02-13T19:41:42Z,2020-02-13T19:41:42Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79967', 'http://dx.doi.org/10.26153/tsw/6992']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Laminated Object Manufacturing,Advanced Laminated Object Manufacturing (LOM) of SiSiC Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/389142a4-face-4589-a8c2-c3e52948915a/download,,"Carbon sheets were used as a starting material for fabrication of SiSiC composites by
advanced LOM. This approach consists of three steps: First a preform was fabricated form
phenolic resin coated carbon paper with a LOM-device. Second the preform was turned into a
carbon preform by pyrolysis in N2-atmosphere. Third pressureless reactive melt infiltration of
silicon into the as fabricated carbon preform, which finally yielded a dense SiSiC composite.
SEM analysis revealed a microstructure consisting of uniformly dispersed β-SiC grains in a
matrix of silicon. The LOM fabricated material exhibited an average four point bending
strength and Youngs modulus of 115 MPa and 165 GPa, respectively.",,,,,,
"['Petrzelka, Joseph E.', 'Frank, Matthew C.']",2021-09-28T19:58:30Z,2021-09-28T19:58:30Z,2009,Mechanical Engineering,,"['https://hdl.handle.net/2152/88167', 'http://dx.doi.org/10.26153/tsw/15108']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Subtractive Rapid Prototying', 'STL models', 'layer-based removal processing', 'tool accessibility']",Advanced Process Planning for Subtractive Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cfbe24e4-e8ab-4024-9751-eba262a2ec7d/download,University of Texas at Austin,"This paper presents process planning methods for Subtractive Rapid Prototyping, which deals with
multiple setup operations and the related issues of stock material management. Subtractive Rapid
Prototyping (SRP) borrows from additive rapid prototyping technologies by using 2½D layer based
toolpath processing; however, it is limited by tool accessibility. To counter the accessibility problem,
SRP systems (such as desktop milling machines) employ a rotary fourth axis to provide more complete
surface coverage. However, layer-based removal processing from different rotary positions can be
inefficient due to double-coverage of certain volumes. This paper presents a method that employs STL
models of the in-process stock material generated from slices of the part along the rotation axis. The
developed algorithms intend to improve the efficiency and reliability of these multiple layer-based
removal steps for rapid manufacturing.",,,,,,
"['Hui, Du Zhao', 'Kai, Chua Chee', 'Sen, Chua Yew', 'Gek, Loh-Lee Keow', 'Tiak, Lim Ser']",2019-09-23T17:18:29Z,2019-09-23T17:18:29Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75980', 'http://dx.doi.org/10.26153/tsw/3079']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Manufacturing,Advanced Sheet Metal Manufacturing using Rapid Tooling 522,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2ff8c60-b253-4427-bcc4-6f8d12b8ddf3/download,,"A closed loop process is proposed for making sheet metal prototyping parts by using advanced computer aided techniques and computer controlled machines. The key aspect of this process is the method used to fabricate and modify the sheet metal
forming tools, which are not necessarily for mass production but should be suitable for short run production or design evaluation of sheet metal products where the prototyping cost and lead-time are greatly reduced. Various approaches are investigated in the preparation of the tooling for onward embossing on a sheet metal. The three indirect approaches use Selective Laser
Sintering (SLS), Stereolithography(SLA), and high speed Computer Numerical Controlled (CNC) milling to build the masters from computer data models. And the masters are then served in the vacuum casting process to generate the non-ferrous
tooling. The direct approach uses DTM’s RapidSteel to produce the metal tooling without going through any secondary process. Comparisons on quality, leading time and cost are presented.",,,,,,
"['Asiabanpour, Bahram', 'Khoshnevis, Behrokh', 'Palmer, Kurt', 'Mojdeh, Mehdi']",2019-11-08T15:30:24Z,2019-11-08T15:30:24Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78323', 'http://dx.doi.org/10.26153/tsw/5410']",eng,2002 International Solid Freeform Fabrication Symposium,Open,SIS Process 25,Advancements in the SIS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a041cdf7-afe3-470d-b02c-43f25936d5c9/download,,"Selective Inhibition of Sintering (SIS) is a new layer-based rapid prototyping process. This paper
reports the progress in research and development of the SIS process. Specific printer path
generation method, experimentation with various powder and inhibitor materials, and systematic
models leading to optimum performance given various factors affecting part strength, surface
quality, and dimensional accuracy are presented.",,,,,,
"['Mahela, T.', 'Cormier, D.', 'Harrysson, O.', 'Ervin, K.']",2020-03-09T15:23:46Z,2020-03-09T15:23:46Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80197', 'http://dx.doi.org/10.26153/tsw/7216']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Electron Beam Melting,Advances in Electron Beam Melting of Aluminum Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/92943da2-836d-4ab8-97fb-3aaf77fd0336/download,,"The high thermal conductivity and melt pool optical reflectivity associated with
aluminum alloys can pose significant challenges for direct-metal SFF processes. The use
of SFF processes to produce aluminum parts is often not cost effective relative to CNC
machining for simple geometries. However, the use of SFF techniques for aluminum
alloys is justified for some applications such as aerospace forgings or high surface area
heat exchangers. This paper describes recent progress in processing aluminum alloys
using the Electron Beam Melting process. Structure and properties will be discussed, as
well challenges associated with high vapor pressure alloying elements such as zinc and
magnesium.",,,,,,
"['Dutson, Alan J.', 'Wood, Kristin L.', 'Beaman, Joseph J.', 'Crawford, Richard H.']",2019-10-23T15:17:08Z,2019-10-23T15:17:08Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76758', 'http://dx.doi.org/10.26153/tsw/3847']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Functional Testing,Advances in Functional Testing with SFF Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4f9703f-d4d5-40e9-98e5-37dfd8accdd7/download,,"Functional testing of SFF parts represents an exciting area of research in solid freeform
fabrication. One approach to functional testing is to use similitude techniques to correlate the
behavior of an SFF model and a product. Previous research at UT Austin has resulted in
development of an empirical similitude technique to correlate the behavior of parts of dissimilar
materials and geometry. Advances in the empirical similitude technique are presented in this
paper. Sources of coupling between material and geometry characteristics that produce errors in
the current empirical similitude technique are outlined. A modified approach that corrects for
such errors is presented. Numerical examples are used to illustrate both the current and the
advanced empirical similitude methods.",,,,,,
"['Tompkins, J.V.', 'Laabi, R.', 'Birmingham, B.R.', 'Marcus, H.L.']",2018-10-03T18:43:19Z,2018-10-03T18:43:19Z,1994,Mechanical Engineering,doi:10.15781/T2WS8J53D,http://hdl.handle.net/2152/68678,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SALD', 'Solid free-form fabrication', 'DES']",Advances in Selective Area Laser Deposition of Silicon Carbide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e74dc268-0af2-46e9-85a1-85234b3b7907/download,,"Selective Area Laser Deposition (SALD) is a Solid Freeform Fabrication (SFF) technique which
uses a scanning laser beam to produce solid material by locally decomposing a gas precursor. In
this work, a focused C02 laser beam strikes a substrate in the presence oftetramethylsilane
(TMS) or diethylsilane (DES), producing silicon carbide objects with high density and no binder
phase. Recent investigation has yielded growth rates up to 2.7mlnJmin in the beam area, and has
eliminated previously noted contamination ofthe optics by a byproduct which mass
spectroscopy identifies as silicon dioxide. This paper reviews a cause of non-uniform growth and
delTIOnstrates the addition of hydrogen and reduced scan speeds to lTIake lTIultilayer parts. In
addition, it presents a lTIethod for in-situ measurement of height of deposited material.",,,,,,
"['Amado, A.', 'Schmid, M.', 'Levy, G.', 'Wegener, K.']",2021-10-05T13:30:38Z,2021-10-05T13:30:38Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88367', 'http://dx.doi.org/10.26153/tsw/15306']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'powder characterization', 'powder flow processing']",Advances in SLS Powder Characterization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7166d153-eff1-4b21-8889-c1a8a20c3b01/download,University of Texas at Austin,"This paper introduces a new Selective Laser Sintering (SLS) powder characterization
methodology. A better understanding regarding powder flow processing range is targeted.
Intrinsic properties of polymers are given from the basic chemical structure and non-intrinsic
ones describe characteristics caused from pre-processing and production. The non-intrinsic ones
are dedicated to the powder. Understanding the particle size distribution and shape coupled with
its ability to flow under the particular SLS processing conditions is desired. In this direction, a
system called Revolution Powder Analyzer is employed and the dynamic powder behavior is
characterized in nearly roll spreading conditions. This allows a sensitive differentiation of
powders regarding their flow-ability and predicts, to a certain extent, the behavior under SLS
conditions.",,,,,,
"['Jacobs, Paul F.', 'Richter, Jan']",2018-04-17T16:41:04Z,2018-04-17T16:41:04Z,1991,Mechanical Engineering,doi:10.15781/T25T3GH0J,http://hdl.handle.net/2152/64329,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['SLA', 'Windownpane', 'Weave', 'SLA-250']",Advances in Stereolithography Accuracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbf7f76c-0bd2-4566-90d4-5a18ad3d3460/download,,"It has been almost four years since the SLA - 1 ushered in the
new technology of StereoLithography, and about 2\ years since 3D
Systems introduced the SLA-250. Since then, nearly 300 systems
have been installed worldwide and are currently providing benefits
in a range of applications which might well be summarized by the
term ""Rapid Prototyping and Manufacturing"" or ""RPM"".
During the past year the accuracy of parts built with
stereoLithography has benefitted significantly from nine important
technological advances. The research and development efforts which
formed the foundation for this progress originated within the
Process, Chemistry and Software departments of 3D Systems.
The following is a listing, and brief description, of the key
features of each of these advances.",,,,,,
"['Sercombe, T.B.', 'Schaffer, G.B.']",2020-02-12T15:06:37Z,2020-02-12T15:06:37Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79934', 'http://dx.doi.org/10.26153/tsw/6960']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Advances in the Production of Infiltrated Aluminium Parts Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b41459fa-1a05-4505-9d85-699423d7b2c4/download,,"Recent advances in a rapid freeform fabrication process for the production of aluminium
parts are considered. The methodology involves the formation of an unconstrained, resin bonded
aluminium powder part by Selective Laser Sintering, the burnout of the resin, the partial
transformation of the aluminium into a rigid aluminium nitride skeleton by reaction with the
atmosphere under a magnesium/alumina blanket and the subsequent infiltration with a second
aluminium alloy. Here we describe the process and consider potential applications. Strategies for
controlling the growth of the aluminium nitride are also to be discussed.",,,,,,
"['Liu, Fei', 'Jingchao, Wang', 'Zhi, Tan', 'Bin, Liu', 'Yue, Guo', 'Zhang, David Z.']",2021-11-09T18:57:26Z,2021-11-09T18:57:26Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90119', 'http://dx.doi.org/10.26153/tsw/17040']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'selective laser melting', 'upper-stage cabin structure', 'integrated design and manufacturing']","An Aerospace Integrated Component Application Based on Selective Laser Melting: Design, Fabrication and Fe Simulation",Conference paper,https://repositories.lib.utexas.edu//bitstreams/9cb14418-ea21-4a16-b179-4999448e6fd8/download,University of Texas at Austin,"Developments in Additive Manufacturing (AM) technologies have enabled the
integrated manufacturing of complex structures with multifunctional performances. Selective
Laser Melting (SLM), as one of them, becomes the candidate for production of metallic aviation
spaceflight structures because of its high precision for controlling architecture and excellent
performance. An aerospace component named Upper-stage Cabin was selected for integrated
design without connectors, and then manufactured by a SLM system using Ti-6Al-4V powder.
The dimensional accuracy of the component was verified through testing; It’s mechanical
response was analyzed under compressive loading test, compared with the results of numerical
simulation. The study found that SLM technology is an effective means for integrated design
and manufacture of Upper-stage Cabin structures for aerospace. The dimensional precision of
the complex integrated structures formed by SLM meets the application requirements. The
formed integrated components have achieved good mechanical properties, which promote the
application of this technology in aerospace field.",,,,,,
"['Cho, Uichung', 'Wood, Kristin L.', 'Crawford, Richard H.']",2019-03-07T18:09:52Z,2019-03-07T18:09:52Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73566', 'http://dx.doi.org/10.26153/tsw/708']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping techniques', 'industries']",Agile Product Testing with Constrained Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8951b4bc-edc2-44c8-a19f-45538d564f4d/download,,"The means to acquire reliable functional information is a critical factor that differentiates product development time and cost. Thanks to advances in solid freeform
fabrication techniques, industries can produce geometrically complex parts within
dramatically reduced time and cost. Even though industries can save significant efforts by performing functional tests rapid prototypes, they still prefer full-scale product tests, especially in later design phases, due to inherent limitations in traditional
similarity methods (TSM). This paper describes a new method to perform reliable
functional tests with rapid prototypes that cannot be properly handled by the TSM.",,,,,,
"['Wudy, K.', 'Drummer, D.']",2021-10-27T22:15:58Z,2021-10-27T22:15:58Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89631,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['aging behavior', 'bulk values', 'part properties', 'interrelation', 'polyamide 12']",Aging Behavior of Polyamide 12: Interrelation Between Bulk Characteristics and Part Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a249bd79-2a3a-4c30-97b3-4474c8b83901/download,University of Texas at Austin,"The high process temperatures in combination with long building times during the laser
sintering process lead to chemical and physical aging mechanisms on the polymeric feed
material. The unmolten partcake material, which acts as a supporting structure, can be removed
after each building process and reused for further processes. However, material as well as bulk
properties are changed due to thermal and mechanical load during the laser sintering process.
Within this paper the interrelation between the aging state, bulk values and resulting
part properties like porosity, surface roughness and mechanical behavior are derived. Therefore,
polyamide 12 powder is used for at least five processing cycles without refreshing. Before and
after each building process, bulk characteristics and changes of the particle surface were
determined. Specimens were manufactured during the laser sintering process in order to study
the part density, roughness and mechanical behavior.",,,,,,
"['Palomino, Donald', 'Bian, Shijie', 'Salcedo, Pedro', 'Navarro, Erick', 'Gopalaiah, Bharath', 'Otis4, Richard', 'Li, Bingbing']",2023-01-26T22:00:35Z,2023-01-26T22:00:35Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117326', 'http://dx.doi.org/10.26153/tsw/44207']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Augmented Reality Training', 'Metal Additive Manufacturing', 'Text Recognition', 'Object Detection']",AI-Powered Augmented Reality Training for Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e9fea74-8767-4804-8338-8259b8eeb7c4/download,,"Metal additive manufacturing (AM) training can cost a company the considerable amount of 
time, cost, and resources. To resolve this challenge, the NSF funded HyperSkill platform was 
applied to create an innovative, immersive training program that integrates AI-powered object 
detection and text recognition into a comprehensive digital twin of the metal AM machine 
operation. This immersive digital twin will support the delivery of just-in-time guidance to 
trainees while also monitoring their actions and providing contextual and personalized feedback 
to accelerate training, foster retention, and maximize transfer to the actual job. The augmented 
reality (AR) training supports the import of 3D assets, no-code authoring of workflows, standard 
operating procedures (SOP), step-by-step instructions, and delivery across a wide variety of AR 
devices. For this study, the specific metal AM operation is based on the Renishaw AM400 in 
both its full and reduced build volume (RBV) configuration.",,,,,,
"['Cawley, J.D.', 'Wei, P.', 'Liu, Z.E.', 'Newman, W.S.', 'Mathewson, B.B.', 'Heuer, A.H.']",2018-10-03T19:18:23Z,2018-10-03T19:18:23Z,1995,Mechanical Engineering,doi:10.15781/T2HH6CR12,http://hdl.handle.net/2152/68681,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['CAM-LEM', 'Solid free-form fabrication', 'powder synthesis']",Al2O3 Ceramics Made by CAM-LEM (Computer-Aided Manufacturing of Laminated Engineering Materials) Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a17c37da-e696-40a4-bedb-e7c9d2cef556/download,,"The concept of CAM-LEM technology is presented and discussed in the context of the fabrication of Al2O3 ceramics. Particular attention is paid to the interplay of green tape characteristics and the unit operations involved in CAM-LEM. Examples of ceramic shapes
difficult to form by conventional methods are described.",,,,,,
"['Weiss, C.M.', 'Marcus, H.L.']",2021-09-30T13:37:30Z,2021-09-30T13:37:30Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88244', 'http://dx.doi.org/10.26153/tsw/15185']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'Selective Area Laser Deposition', 'SALD joining', 'carbides', 'nitrides', 'ceramics', 'CVD gas decomposition', 'aluminum oxide']",Al2O3 Precursor Evaluation for SALD Joining,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56ca323d-8241-49f2-9e4f-bb7a00a057d4/download,University of Texas at Austin,"SFF technology is not limited to the creation of components and objects. Freeform
technology can be a mechanism for joining of materials. By defining the space between two
objects as the boundary for a free-form object it is possible to form a three dimensional joint fill.
Selective Area Laser Deposition or SALD, has been used for free form and joining of carbides
and nitrides but has the potential to make other classes of ceramics. By selecting a metal-organic
precursor and an oxidizer, an oxide can be created by CVD gas decomposition. In this study such
oxide joint fill precursors are studied, particularly for alumina.",,,,,,
"['Bártolo, Paulo', 'Lagoa, Ricardo', 'Mendes, Ausenda']",2019-11-15T16:09:45Z,2019-11-15T16:09:45Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78419', 'http://dx.doi.org/10.26153/tsw/5506']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Alginate-Based,Alginate-Based Rapid Prototyping System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5177bf3-78b8-40e3-beaa-ee65a0d8fba1/download,,"Alginate hydrogels are an import class of ionic biopolymers for medical and biotechnological
applications, produced by the combination of alginate with a proper cross-linking agent.
During the gel formation, cross-links can be formed between the alginate chains and cationic
species, changing the elastic behaviour of the material that controls the volume change
phenomena of the gels.
This paper proposes a new rapid prototyping system to produce three-dimensional alginate
structures by extruding, layer-by-layer, a previously prepared solution of sodium alginate in
water mixed with a solution of calcium chloride, both of known concentration. The building
process to obtain these gel structures is described, from a chemical point of view, and some
obtained structures are shown. The alginate concentration over both the kinetics and accuracy
effects of the process is investigated. The preliminary findings of this research work promise
to open an exciting new area for medical applications.",,,,,,
"['Arndt, Alexander', 'Hackbusch, Heike', 'Anderl, Reiner']",2021-10-21T18:40:31Z,2021-10-21T18:40:31Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89423,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D nesting', 'optimization', 'algorithm']",An Algorithm-Based Method for Process-Specific Three-Dimensional Nesting for Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2cbf39ce-e17a-4ba0-b798-801640b56a89/download,University of Texas at Austin,"To achieve optimal and high-quality results through additive manufacturing, the process-and technology-specific orientation and positioning of components within the virtual space, the so-called nesting, is essential. Primarily the nesting step is examined in this paper. From a scientific
perspective it is a matter of examining this process and furthermore to analyze the optimal insertion
of supporting structures, since the critical machine-specific parameters have been insufficiently
studied. Within this paper a new multi-criteria optimization based on a conceptual algorithm is
proposed. The most important point is the consideration of a technical and not only geometric
nesting process. The objective is the demonstration of restrictions and boundary conditions and a
first developing for a new approach for the nesting process. As an example, the influence of the
orientation of the spring rate is presented with a sample component here. Furthermore, there will
be a prototype implementation and a short validation. Finally, a brief conclusion and an outlook is
given.",,,,,,
"['Gardner, J.A.', 'Nethercott-Garabet, T.', 'Kaill, N.', 'Campbell, R.I.', 'Bingham, G.A.', 'Engstrøm, D.S.', 'Balc, N.O.']",2021-11-15T21:24:49Z,2021-11-15T21:24:49Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90278', 'http://dx.doi.org/10.26153/tsw/17199']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '5-axis', 'tool path', 'material extrusion', 'G-code']",Aligning Material Extrusion Direction with Mechanical Stress via 5-Axis Tool Paths,Conference paper,https://repositories.lib.utexas.edu//bitstreams/71069994-e807-495b-9b05-b025680bc454/download,University of Texas at Austin,"Mechanical properties of parts fabricated via the Material Extrusion (ME) process can be
improved by optimising process settings, however, their properties are strongly influenced by
build orientation due to the stair-stepping effect initiating cracks whilst under load. 5-axis ME
enables the fabrication of parts without the layer-by-layer restrictions that conventional 3-axis
strategies impose. By aligning extrusion direction with high stress tensors, 5-axis tool paths can
be used to reduce the effects of weak inter-layer bonds.
To establish performance differences between parts manufactured by either strategy,
wave spring-inspired geometry was selected for production, due to the multi-directional tensile
loads acting throughout the material. 5-axis and 3-axis tool paths were generated via the
Grasshopper 3D virtual environment within Rhinoceros 3D and MakerBot Desktop, and
manufactured using a 5AXISMAKER and a MakerBot Replicator 2, respectively. To evaluate
performance differences between the two strategies, compression tests were conducted on the
parts.",,,,,,
"Drake, Samuel H.",2018-04-10T18:56:39Z,2018-04-10T18:56:39Z,1990,Mechanical Engineering,doi:10.15781/T22J68N1S,http://hdl.handle.net/2152/64247,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Alpha_1', 'SFF techniques', 'NURBs']","ALPHA_I, Remote Manufacturing, and Solid Freeform Fabrication",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c3ee93b8-37d9-4fa8-89ce-08c104274c3b/download,,"Alpha_l is a nonuniform rational B-spline (NURBs) based solid modeling system that
has been developed at the University of Utah over the past 10 years. In addition to being
useful in modeling objects that are described by simple rotation and extrusion operations,
the real power of Alpha_l is demonstrated in the modeling of complex parts with sculptured
surfaces. For the past several years, a major research thrust has been to use Alpha_l to
semi-automatically generate process plan information and numerical control code to manufacture
mechanical parts directly from the models. A long term goal is to support an on-line
remote manufacturing facility for producing prototype parts. Recently, a 3D Systems stereo
lithography machine has been added to the advanced manufacturing laboratory. The stereo
lithography process and other SFF techniques are of particular interest for supporting a
remote manufacturing facility in that these processes are inherently much safer than numerically
controlled machining. Special Alpha_l interfaces including a new slicing algorithm
are being developed for the SFF machine use. By generating a SFF part directly from
its NURBs description, Alpha_l should facilitate the manufacture of complex parts while
providing smoother surfaces.",,,,,,
"['Schnell, N.', 'Siewert, M.', 'Kleszczynski, S.', 'Witt, G.', 'Ploshikhin, V.']",2021-11-18T17:27:19Z,2021-11-18T17:27:19Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90437', 'http://dx.doi.org/10.26153/tsw/17358']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion of metals', 'LPBF-M', 'thermocouple', 'finite element modeling', 'FEM', 'validation', 'thermocouple', 'stainless steel 1.4542', 'GP1']",Alternative Approach on an In-Situ Analysis of the Thermal Progression During the LPBF-M Process Using Welded Thermocouples Embedded into the Substrate Plate,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3947858f-d621-41fc-afb4-309cb7acbeee/download,University of Texas at Austin,"Laser powder bed fusion (LPBF-M) is a very potent technology for creating highly individualized, complex, and functional metal parts. One of the major influencing factors is the thermal progression. It
significantly determines size accuracy, microstructure and process stability. Therefore, creating an enhanced understanding of thermal phenomena through measurements and simulations is crucial to increase the reliability of the technology. Current research is mainly based on temperature measurements
of the upper layer, leaving major scope for the conditions at the substrate-part-interface. This area is of
utmost technical importance because it serves as the main heat sink. Insufficient heat dissipation leads
to accumulations of heat, deformations, and process breakdowns. This contribution presents a simple
and flexible method to analyze the thermal progression close to the part inside the substrate plate. The
acquired data shows very high consistency. Additionally, the results are compared to a model created
using an ISEMP developed FEM-Software which shows promising results for validation studies.",,,,,,
"['Spratt, M.', 'Newkirk, J.', 'Chandrashekhara, K.']",2021-11-02T14:52:59Z,2021-11-02T14:52:59Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89817,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['syntactic foam', 'aluminum matrix', 'additive manufacturing', 'microsphere flotation', 'microsphere fracture']",Aluminum Matrix Syntactic Foam Fabricated with Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90e3d3fe-e31f-4d93-88e6-4540ebe39c4e/download,University of Texas at Austin,"Syntactic foams are lightweight structural composites with hollow reinforcing particles
embedded in a soft matrix. These materials have applications in transportation, packaging, and
armor due to properties such as relatively high specific stiffness, acoustic dampening, and impact
absorption. Aluminum matrices are the most widely studied of metal matrix syntactic foams, but
there is little to no research in regards to processing the foams with additive manufacturing. It is
theorized that the fast cooling rates and limited kinetic energy input of additive could reduce two
issues commonly associated with processing syntactic foams: microsphere flotation in the melt
and microsphere fracture during processing. In this study, 4047 aluminum blended with glass
particles was deposited on a 4047 Al substrate using an additive process. Characterization of the
foams include mechanical testing and microstructural analysis.",,,,,,
"['Qi, Yang', 'Zhang, Hu', 'Zhu, Haihong', 'Nie, Xiaojia', 'Zeng, Xiaoyan']",2021-11-18T00:47:12Z,2021-11-18T00:47:12Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90377', 'http://dx.doi.org/10.26153/tsw/17298']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['aluminum-lithium', 'Al-Li', 'laser powder bed fusion', 'LPBF']",An Aluminum-Lithium Allloy Produced by Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5ff4a4e-fb07-4515-84e6-6ef404dc0762/download,University of Texas at Austin,"Aluminum-lithium (Al-Li) alloys are promising to replace traditional high-strength
aluminum alloys in aerospace and military industries due to their low density, high specific strength,
and excellent corrosion resistance. However, there is little research focused on the laser powder
bed fusion (LPBF) of Al-Li alloys due to their poor weldability and high crack susceptibility. In
this study, the feasibility of the Al-Li alloy fabricated by LPBF was investigated. The effect of the
processing parameters on the densification and crack formation behavior was studied. Finally, after
optimizing the processing parameters, crack-free and nearly fully dense 2195 Al-Li alloy 3D-printed samples were obtained. A relative density of 99.92% and a microhardness of 89.1 HV were
achieved.",,,,,,
"['Zhang, Y.', 'Bernard, A.']",2021-10-18T22:36:23Z,2021-10-18T22:36:23Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89274,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'feature based process planning', 'knowledge based process planning', 'CAPP system']",AM Feature and Knowledge Based Process Planning for Additive Manufacturing in Multiple Parts Production Context,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b6cee97-2bc9-4f92-8383-4f91e2b48493/download,University of Texas at Austin,"Additive Manufacturing (AM) has played an important role in manufacturing, especially in
customized production. It is an ideal 'Concurrent Manufacturing' which enables fabricating a
group of same or even different multiple parts simultaneously within one build volume due to
its unique layer by layer processing way. However, there is very few available methods or
tools for users, e.g. the AM manufacturing service bureaus, to optimize the process and
production plan in multiple parts production context. To deal with this problem, this paper
introduces an AM feature and knowledge based systematic process planning strategy. The
main contents and key issues of process planning for AM in multiple parts production context
are analyzed. Then, a developing CAPP system based on a systematic process planning
framework for AM in this multiple parts production context is presented. Finally, some test
examples are applied to demonstrate the functions and effectiveness of some key modules of
the developing system.",,,,,,
"['Muhammad, M.', 'Masoomi, M.', 'Torries, B.', 'Shamsaei, N.', 'Haghsenas, M.']",2021-11-11T15:13:49Z,2021-11-11T15:13:49Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90215', 'http://dx.doi.org/10.26153/tsw/17136']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['instrumented indentation', 'additive manufacturing', 'Ti-6Al-4V', 'creep stress exponent']",Ambient-Temperature Indentation Creep of an Additively Manufactured Ti-6Al-4V Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b54a5218-389f-470c-b578-71a926cc632b/download,University of Texas at Austin,"Instrumented indentation testing technique is a robust, convenient, and non-destructive
characterization method to study time-dependent plastic deformation in metals and alloys at
ambient and elevated temperatures. In this current research, the depth-sensing indentation creep
behavior of additively manufactured Ti-6Al-4V alloy and its mechanism were studied at ambient
temperature for different additive manufacturing scan direction and scan size. Indentation creep
tests were conducted through a dual-stage scheme (loading followed by a constant load-holding)
at different peak load of 250, 350, and 450 mN with holding time of 400 s. In addition,
microstructural quantitative analyses, using optical microscopy and scanning electron microscopy,
were performed. Microstructural assessments and depth-sensing creep characterizations were then
used to assess processing parameter/ microstructure/ creep properties relationships for this alloy.",,,,,,
"['Espalin, David', 'Arcaute, Karina', 'Anchondo, Eric', 'Adame, Arturo', 'Medina, Francisco', 'Winker, Rob', 'Hoppe, Terry', 'Wicker, Ryan']",2021-09-29T22:38:08Z,2021-09-29T22:38:08Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88222', 'http://dx.doi.org/10.26153/tsw/15163']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['fused deposition model', 'additive manufacturing', 'bonding', 'bonding methods', 'thermoplastic material', 'FDM-manufactured parts', 'bonding strength']",Analysis of Bonding Methods for FDM-Manufactured Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a483bbc-75f5-40b8-a1fb-0ec631bd9c3b/download,University of Texas at Austin,"The fused deposition modeling (FDM) additive manufacturing (AM) technology has been
valuable for producing a variety of concept models, functional prototypes, end-use parts and
manufacturing tools using a range of durable thermoplastic materials. The largest individual
component that can be produced in FDM depends on the dimensions of the build chamber for the
specific FDM system being used, with a maximum build chamber size available of 914 x 610 x
914 mm. This limitation is not unique to FDM as all AM systems are constrained by a build
chamber. However, by using thermoplastic materials, individual components can be bonded
together using different methods to form a single piece. Bonding can be used to help reduce
building time and support material use, and also allows for the fabrication and assembly of final
products larger than the build chamber. This work investigated different methods for bonding
FDM-manufactured parts, including the use of five different adhesives and solvents as well as
two different welding techniques (hot air welding and ultrasonic welding). The available FDM
materials investigated included acrylonitrile butadiene styrene (ABSi, ABS-M30, ABS-M30i),
polycarbonate (PC, PC-ABS, PC-ISO), polyphenylsulfone (PPSF), and ULTEM 9085. Bonding
strengths were characterized by comparing ultimate tensile strengths at break and analyzing the
mode of failure. Overall, the bonding method of hot air welding produced the strongest bond for
all the materials investigated except for ULTEM 9085 for which the strongest bond was achieved
with the two-part epoxy adhesive Hysol E-20HP.",,,,,,
"['Isa, Mohammed A.', 'Yiğit, Ismail Enes', 'Lazoglu, Ismail']",2021-11-11T16:22:27Z,2021-11-11T16:22:27Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90235', 'http://dx.doi.org/10.26153/tsw/17156']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['freeform overhangs', 'build direction', 'mutli-axis additive manufacturing', 'additive manufacturing']",Analysis of Build Direction in Deposition-Based Additive Manufacturing of Overhang Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5be8db77-3358-4b8c-af21-96a0a263d228/download,University of Texas at Austin,"Additive manufacturing (AM) has gained repute as a direct method of fabrication of
complex parts. However, the requirement for each layer to be structurally supported can make parts with
overhangs hard to produce without alterations to the parts. This work proposes using multi-axis additive
manufacturing to fabricate and analyze freeform overhangs such as bridge structures. Multi-axis AM
allows reorientation of the build direction so that overhangs can be 3D printed. Consequently, decision on
the build orientation is necessary and its result should be analyzed. The effect of the AM build
direction with respect to the overhang’s local surface directions will be studied. A Rhinoceros® plugin is
designed to generate the path of the multi-axis AM for the unsupported components like roofs, bridges and
protrusions. The effects of the build direction on the surface quality and deformation of the components are
studied.",,,,,,
"['Fathi, S.', 'Dickens, P. M.', 'Hague, R. J. M.', 'Khodabkhski, K.', 'Gilbert, M.']",2020-03-11T15:13:14Z,2020-03-11T15:13:14Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80248', 'http://dx.doi.org/10.26153/tsw/7267']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['solid free-form fabrication', 'Ink-jetting']",Analysis of Droplet Train/Moving Substrate Interactions in Ink-Jetting Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/774a34be-0bbd-40b7-9429-0bce1c54b30a/download,,"Ink-jetting technology has been applied to several processes in solid free-form
fabrication (SFF) wherein droplets impinge onto a substrate to deposit the build material.
Droplet impact behaviour on a surface has been the interest of many researchers; however,
few studies have been undertaken to investigate the interaction of droplets with the moving
substrate. This paper reports the impact behaviour of the droplets jetted at different
frequencies onto a substrate moving over a range of velocities. The phenomena associated
with the interaction were classified into three main regimes.",,,,,,
"['Alqahtani, Hassan', 'Keller, Eric', 'Ray, Asok', 'Basak, Amrita']",2021-11-18T00:43:48Z,2021-11-18T00:43:48Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90376', 'http://dx.doi.org/10.26153/tsw/17297']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['fatigue damage', 'crack initiation', 'ultrasonic test', 'digital microscope', 'signal attenuation', 'discrete wavelet transform']",Analysis of Fatigue Crack Evolution Using In-Situ Testing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b292e60f-b871-4bbc-83bd-8c47207801ff/download,University of Texas at Austin,"The objective of the current work is to investigate the feasibility of an in-situ technique to
characterize the evolution of fatigue failure in conventionally manufactured aluminum parts in
real time. An in-situ fatigue testing setup integrated with ultrasonic transducers and a digital
microscope allows for the systematic study of fatigue crack evolution in aluminum specimens.
The resulting data from experimentation, characterization, and analysis are integrated to gain
unprecedented insights into the evolution of fatigue failure in wrought aluminum parts. The
learning from this work will be further implemented on additively manufactured specimens.",,,,,,
"['Gaytan, Sara M.', 'Cadena, Monica', 'Aldaz, Mayela', 'Herderick, Edward', 'Medina, Francisco', 'Wicker, Ryan']",2021-10-12T17:59:57Z,2021-10-12T17:59:57Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88708', 'http://dx.doi.org/10.26153/tsw/15642']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['ceramic fabrication', 'ferroelectric ceramics', 'binder jetting', 'dielectric capacitors', 'sensors', 'integrated circuits', 'M-Lab system', 'ExOne']",Analysis of Ferroelectric Ceramic Fabricated by Binder Jetting Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1329182a-eca5-470a-9bed-f0ab8c5ebb71/download,University of Texas at Austin,"The M-Lab system from ExOne was used to fabricate 3D structures of BaTiO3 ceramic
with applications that include dielectric capacitors, sensors, and integrated circuits. For this
project, layer thicknesses of 15 and 30 μm and various percentages of binder saturation were
used to fabricate components from powder. An organic binding agent was utilized during the
printing process and later burned out at ~600°C prior to sintering. Multiple building parameters
and sintering profiles were analyzed and compared in an attempt to obtain dense parts while
examining shrinkage percentage variations.",,,,,,
"['Rhodes, Andrew', 'Smith, Tyler', 'Sharpe, Christian', 'Kunc, Vlastimil', 'Duty, Chad']",2023-01-20T16:49:50Z,2023-01-20T16:49:50Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117265', 'http://dx.doi.org/10.26153/tsw/44146']",eng,2022 International Solid Freeform Fabrication Symposium,Open,LFAM,Analysis of Fiber Attrition and Mechanical Performance in Large-Format Additive Manufacturing of Long-Fiber Reinforced Polymer Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9008ad8-78ca-454a-849d-052bd8c36564/download,,"Understanding the residual fiber length of discontinuous fiber-reinforced thermoplastics in 
large-format additive manufacturing (LFAM) is of significant interest since the residual fiber 
length influences the mechanical properties of the final part. Currently, the attrition of long fiber 
reinforcement during screw-extrusion LFAM is an understudied subject, although the residual 
fiber length is among the most important microstructural properties of fiber-reinforced composites. 
A contributing factor the lack of focus in this area is the questionability and variety of convoluted 
fiber measurement methods. This study evaluates the relationship between printing speed, the final 
fiber length, and resultant mechanical properties for 4 mm pultruded thermoplastic polyurethane 
(TPU) pelletized feedstock and seeks to fully document a fiber length distribution (FLD) 
measurement method. Samples were printed at several processing speeds and subjected to fiber 
length analysis and tensile testing. Fiber length analysis was performed using a combination of 
novel and proven techniques for improved repeatability and reliability of results. This study seeks 
to improve understanding in the choice of machine design, material selection, and processing 
parameters for optimal mechanical properties.",,,,,,
"['Cholewa, S.', 'Jacksch, A.', 'Drummer, D.']",2024-03-25T22:01:08Z,2024-03-25T22:01:08Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124310', 'https://doi.org/10.26153/tsw/50918']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['flow', 'polymer', 'laser', 'powder bed', 'manufacturing', 'engineering', '2023 Solid Freeform Fabrication Symposium']","Analysis of Flow Additives in Laser-Based Powder Bed Fusion of Polymers: Implications for Flow Behavior, Processing, Temperature Profile, and Part Characteristics",Conference paper,https://repositories.lib.utexas.edu//bitstreams/6c4f9f85-4d9a-4bc9-966c-df447ff87c94/download,University of Texas at Austin,"Powder bed fusion of polymers requires the use of flow additives to ensure adequate flowability of the
feedstock material. However, information regarding flow additives and their load is limited, as is an
understanding of their impact on processing conditions. This study investigates the flow behavior using
static and dynamic measurements under process conditions, focusing on the influence of flow additives.
Subsequently, processing studies are conducted using thermography to analyze the laser-material interaction.
The characteristics of parts produced from Polypropylene and Polyamide 12 systems are also examined. The
findings of this research enhance the understanding of the impact of flow additives on the processing conditions
of laser-based powder bed fusion of polymers, potentially leading to optimized process parameters and
improved part quality and mechanical properties.",,,,,,
"Cunico, Marlon Wesley Machado",2021-11-04T18:14:34Z,2021-11-04T18:14:34Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89994', 'http://dx.doi.org/10.26153/16915']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'flexible manufacturing systems', 'production']",Analysis of Hybrid Manufacturing Systems Based on Additive Manufacturing Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/72e89985-b1c1-41a8-ad6a-e3bfb9f83a30/download,University of Texas at Austin,"Along the last year, additive manufacturing technologies has been proving to be a real game
changer in several market segments. Nevertheless, the main foundation of production and flexible
manufacturing systems generally considers classical technologies. For that reason, the present
work aim to propose and investigate manufacturing systems which includes additive manufacturing
technologies as part of the main or secondary production flow. As result, it was identified that
several marketing segments, types of components and different annual volumes tend to be better
attended by hybrid flexible manufacturing systems which includes additive manufacturing
technologies.",,,,,,
"['Pitz, K.', 'Anderl, R.']",2021-11-18T16:44:28Z,2021-11-18T16:44:28Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90422', 'http://dx.doi.org/10.26153/tsw/17343']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['dentures', 'CAD', 'CAM', 'layering strategies', 'thickness measurements']",Analysis of Layer Arrangements of Aesthetic Dentures as a Basis for Introducing Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63956822-c032-456c-9d57-856ef0b27503/download,University of Texas at Austin,"Aesthetic dentures are highly individual products, needing to adapt to the patient’s natural
dentition in both color and shape. In general, dentures are geometrically complex structures,
consisting of several layers of different materials, which are applied consecutively. This is why
efforts are being made to introduce additive manufacturing into the production process of aesthetic
dentures which is to date largely based on manual work of skilled professionals. In order to
successfully apply additive manufacturing accurate models of the denture to be produced are
essential. In this paper the layer arrangements of dental crowns from real patient cases are analyzed.
Different approaches, based on normal vectors, cylindrical coordinates, spherical coordinates and
paraxial rays, are compared to each other. The emphasis of this comparison lies on transferring
layering strategies from analyzed patient cases to future patient cases where the geometry might be
slightly different but a similar optical impression is desired. The most suitable approach for this
purpose has been identified, implemented and tested.",,,,,,
"['Johnston, Scott R.', 'Reed, Marques', 'Wang, Hongqing V.', 'Rosen, David W.']",2020-03-02T14:58:38Z,2020-03-02T14:58:38Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80129', 'http://dx.doi.org/10.26153/tsw/7150']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Stereolithography Apparatus,Analysis of Mesostructure Unit Cells Comprised of Octet-truss Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b33effd-6aba-4f63-a72b-b76eefdb89ea/download,,"A unit truss finite element analysis method allowing non-linear deformation is employed to
analyze a unit cell comprised of n
3
 octet-truss structures for their stiffness and displacement
compared to their relative density under loading. Axial, bending, shearing, and torsion effects are
included in the analysis for each strut in the octet-truss structure which is then related to the
mesostructure level (unit cell). The versatility of additive manufacturing allows for the
fabrication of these complex unit cell truss structures which can be used as building blocks for
macro-scale geometries. The finite element calculations are compared to experimental results for
samples manufactured on a Stereolithography Apparatus (SLA) out of a standard resin.",,,,,,
"['Lopes, Amit J.', 'Ramos, Luis C.', 'Saenz, David', 'Morton, Philip', 'Terrazas, Cesar A.', 'Choudhuri, Ahsan', 'Wicker, Ryan']",2021-11-30T20:46:03Z,2021-11-30T20:46:03Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90541', 'http://dx.doi.org/10.26153/tsw/17460']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['powder removal', 'Ti-6Al-4V', 'electron beam powder bed fusion', 'electron beam melting']",Analysis of Powder Removal Methods for EBM Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc789d5f-dbb5-45cc-b3af-2770523a2fed/download,University of Texas at Austin,"Additive Manufacturing (AM) allows the creation of complex geometries that are not
achievable through subtractive manufacturing. Regardless of the advantages that 3D Printing
offers, technology limitations often constraints the desired geometry. When fabricating Ti-6Al4V parts in Electron Beam Powder Bed Fusion (EBPBF), the electron beam is used to preheat the
powder bed to maintain the desired temperature gradient during the build. One disadvantage of
EBPBF during the fabrication process is the trapped powder within internal channels gets partially
sintered and require extra processing. This research analyzes several powder removal methods
and compares their effectiveness. This work utilizes two types of samples, both made of Ti-6Al4V in EBPBF; with geometries that resemble typical features when designing a component. The
target weight of each cylinder is calculated based on dimensions and effective density of the
sample. The results summarizing the effectiveness of each method are presented.",,,,,,
"['Mireles, Jorge', 'Adame, Arturo', 'Espalin, David', 'Medina, Francisco', 'Winker, Rob', 'Hoppe, Terry', 'Zinniel, Bob', 'Wicker, Ryan']",2021-10-04T21:16:01Z,2021-10-04T21:16:01Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88348', 'http://dx.doi.org/10.26153/tsw/15287']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'fluid pressure', 'Fused Deposition Modeling', 'sealant', 'end-use applications']",Analysis of Sealing Methods for FDM-fabricated Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90d5327d-5b37-431e-b5a6-4ca3ac8f19c2/download,University of Texas at Austin,"As a result of the layer-by-layer deposition characteristics of Additive Manufacturing
(AM) processes, fabricated parts exhibit limiting qualities and have yet to achieve the
requirements for end-use applications. Specifically, the use of AM-fabricated parts in fluid
pressure applications is limited due to part porosity as well as non-optimized building variables
(e.g., build orientation and material properties). In an effort to extend the use of AM in more
applications involving fluid pressure, parts manufactured with Fused Deposition Modeling
(FDM) were sealed with a variety of sealants and tested under applied pressure. Eleven sealants
with diverse chemical properties were applied to multiple geometries of FDM-fabricated
pressure caps through brushing or vacuum infiltration. The caps were installed on pressure
vessels and subsequently tested while safety precautions were taken to avoid catastrophic failure
(i.e., exploding) caused by pressure differentials. Results of the testing provides a sealing
method using BJB TC-1614 that enables FDM-fabricated parts to withstand pressures up to ~276
kPa (40psi) through brushing and ~138 kPa (20 psi) through vacuum infiltration. Other
noteworthy sealants (Minwax Sanding Sealer, Minwax Polyurethane Oil Based, PRO Finisher
Water-Base Polyurethane) that are readily available to consumers and easy to apply (i.e. no
mixing ratios to follow, long working times) also had notable results by withstanding pressures
up to ~207 kPa (30 psi). In addition, an analysis on dimensional changes was performed to
determine the absolute difference between as-built and surface-treated parts. Parts that were
infiltrated with BJB TC-1614 showed less dimensional changes (average absolute change of
0.104 mm) than parts that were brushed (average absolute change of 0.231 mm) however one-part sealants had smaller dimensional changes (maximum absolute change for one-part sealants
of 0.065 mm for infiltration and 0.171 for brushing) with noteworthy results in pressure testing.
Benefits of filling voids within FDM-manufactured parts enables end-use applications such as
hermetic housings for biomedical devices and pipes/covers for thermodynamic systems such as
heat exchangers.",,,,,,
"['Szucs, Tamas D.', 'Brabazon, Dermot']",2020-03-10T15:17:21Z,2020-03-10T15:17:21Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80215', 'http://dx.doi.org/10.26153/tsw/7234']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Tissue Engineering,Analysis of the Effects of 3DP Parameters on Part Feature Dimensional Accuracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69be293d-1c59-4a0a-9067-76ca858d519f/download,,"3D printing (3DP) is a widely investigated scaffold manufacturing process for Tissue
Engineering (TE). Useful scaffold geometries should have high porosity (60-80%) with small
(100-500 μm) interconnected pores. Therefore dimensional accuracy on the micron level is one
of the crucial parameters of the bone scaffolds. Previously it was shown that the behavior of
scaffold geometries can be well simulated with Finite Element Modeling (FEM) however the
prediction of actual strength and stiffness values are dependent on dimensional accuracy. This
accuracy is in turn dependent on several parameters including particle size and shape, powderbinder interaction, and machine setup. In this work different scaffold strut sizes (0.3 - 0.5 mm)
have been fabricated using two different plaster powders (zp102 and zp130) with variations in
shell saturation levels, part print position, and part print orientation. The parameters for each
powder were analyzed using a full 35
factorial experimental design. It was found that the part size
and orientation had a significant effect on the dimensional accuracy while the influence of the
shell saturation and position was relatively small. The results allow for better dimensional
specification for scaffold geometry fabrication by defining the process parameters in 3DP that
may be used further in scaffold accuracy optimization.",,,,,,
"['Jamal, N.M.', 'Dalgarno, K.W.']",2019-10-24T17:41:54Z,2019-10-24T17:41:54Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77404', 'http://dx.doi.org/10.26153/tsw/4493']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Viscoelasticity,Analysis of the Influence of Viscoelasticity in Curl Development in SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a60491fb-caba-4435-8ebc-97a123fc11c2/download,,"Curl in selectively laser sintered parts arises mainly from thermal distortion of parts within
the build volume during processing. This results in nominally flat surfaces which lie
horizontally in the part bed becoming warped. This paper reports on the use of finite element
techniques to model curl development in polymer materials, and in particular on the influence of
viscoelasticity on how curl develops. The development of time-dependent material models is
reported, and the results of the implementation of these models presented, together with a
comparison of the results with experimental data.",,,,,,
"['Hoppe, B.', 'Enk, S.', 'Schleifenbaum, J.H.']",2021-11-18T18:23:23Z,2021-11-18T18:23:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90456', 'http://dx.doi.org/10.26153/tsw/17377']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'schlieren', 'shadowgraph', 'process development', 'shielding gas flow', 'process stability', '316L stainless steel']",Analysis of the Shielding Gas Dependent L-PBF Process Stability by Means of Schlieren and Shadowgraph Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ab19423-1f87-496e-84db-218ae4a76bf5/download,University of Texas at Austin,"Ensuring a robust and reproducible Laser Powder Bed Fusion (L-PBF) process depends on
the design of the shielding gas flow in the corresponding manufacturing system. The gas flow
assures the removal of particles from the process zone that emerge from the interaction with the
laser irradiation. Minor disturbances may influence the stability of the L-PBF-Process and cause
defects in final parts produced. The objective of this work comprises visualizing the convection
processes and particle dynamics to analyze their influence on process stability. Therefore, a high
speed camera based Schlieren and Shadowgraph setup is used to visualize convection flows as well
as trajectories of metallic condensate and particles with up to 10,568 fps. This arrangement allowed
investigating the influence of shielding gas flow conditions on single melt tracks. Corresponding
results and studies on the interaction between laser irradiation and particles in varying shielding
gas flow conditions are contents of this work.",,,,,,
"['Lee, Cheol H.', 'Thomas, Charles L.']",2018-12-06T22:23:40Z,2018-12-06T22:23:40Z,1997,Mechanical Engineering,doi:10.15781/T28W38N9T,http://hdl.handle.net/2152/71436,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'manufacturability']",An Analysis Technique for Layered Manufacturing Based on Quasi-Wavelet Transforms,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aacf7bed-19c8-4c46-892b-d0149cb090b9/download,,"An analysis technique based on the Wavelet transform (WT) has been recently introduced
that allows the spatial frequency content of objects produced by layered manufacturing (LM)
techniques to be interpreted in terms ofmanufacturable features. (Lee and Thomas, 1997) Using
Haar's wavelet as a basis function, layers with vertical edges are modeled exactly. Using
analysis, a 3D model can be transformed, filtered, and inverse transformed resulting in an image
ofthe part as it would look if constructed from layers of a specific thickness. In order to extend
this analysis to construction techniques using higher order edges (ruled surface edges or curved
edges), the quasi-wavelet transform (QWT) is introduced. QWT analysis is conceptually the
same as WT analysis, except that the basis function can be selected by the user, allowing exact
analysis of layered manufacturing techniques using higher order construction algorithms. This
work is supported by a grant from the University ofUtah Research Foundation.",,,,,,
"Cunico, Marlon Wesley Machado",2021-11-03T20:19:15Z,2021-11-03T20:19:15Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89922,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'finite element method', 'anisotropy']",Analytical and Experimental Characterization of Anisotropic Mechanical Behaviour of Infill Building Strategies for Fused Deposition Modelling Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e8c1d21-9e0d-453a-acfc-daf30e3ff795/download,University of Texas at Austin,"As consequence of the 3d printing extraordinary rising along the last years, product development
fields are facing new challenges. In addition, it is notary that low cost additive manufacturing, as
such fused filament fabrication (FFF), result in objects with anisotropic mechanical behaviour.
Nevertheless, there is still lacking studies that highlight a proper specification of those mechanical
proprieties. For that reason, the main goal of this work is to present a mechanical characterization
of anisotropic behaviour of FFF objects as a function of infill strategy using a finite element
method. In this work, the main effect of building parameters were investigated in addition the
identification of generalized elasticity and failure mode formulations. By the end, the general
recommendation for objects building was sketched in order to support new strength based
developments.",,,,,,
"['Schonrath, Hanna', 'Wegner, Jan', 'Frey, Maximilian', 'Soares Barreto, Erika', 'Elspab, Arno', 'Schnell, Norman', 'Erdmann, Benjamin H.R.', 'Neises, Julian', 'Ellendt, Nils', 'Busch, Ralf', 'Kleszczynski, Stefan']",2024-03-26T16:56:27Z,2024-03-26T16:56:27Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124372', 'https://doi.org/10.26153/tsw/50980']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['bulk metallic glasses', 'additive manufacturing', 'PBF-LB/M', 'Rosenthal model']",Analytical Modeling of Cooling Rates in PBF-LB/M of Bulk Metallic Glasses,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd4ba854-85d5-43e8-b351-4026847cb444/download,University of Texas at Austin,"Additive manufacturing through laser powder bed fusion (PBF-LB/M) inheres great
potential for the processing of bulk metallic glasses (BMGs). The size-independent high cooling
rates during the process benefit the fabrication of large and elaborate amorphous components.
Albeit, partial crystallization poses a challenge in additively manufactured BMGs, potentially
limiting the resulting mechanical properties. In this matter, the complex thermal history during
processing often states a remaining uncertainty. Besides in situ measurements and numerical
estimations, analytical models can be used to achieve a deeper understanding of the transient
temperature evolution. In this work, an iterative solution to the analytical Rosenthal equation is
developed and applied to ZrCuAlNb- and CuTiZrNi-BMGs to predict melt pool dimensions
and cooling rates during PBF-LB/M. Therefore, temperature-dependent thermal properties are
determined via laser flash measurements. The effective absorptivity of the two materials is
measured, and single-line experiments were performed as a validation for the approach.",,,,,,
"['Lindermann, C.', 'Jahnke, U.', 'Moi, M.', 'Koch, R.']",2021-10-05T18:39:19Z,2021-10-05T18:39:19Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88402', 'http://dx.doi.org/10.26153/tsw/15341']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'product lifecycle', 'activity based costing', 'cost drivers']",Analyzing Product Lifecycle Costs for a Better Understanding of Cost Drivers in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e98472c-0a13-4fed-8db5-c965d9192dd1/download,University of Texas at Austin,"The costs of additive manufactured parts often seem too high in comparison to those of
traditionally manufactured parts, as the information about major cost drivers, especially for
additive manufactured metal parts, is weak. Therefore, a lifecycle analysis of additive
manufactured parts is needed to understand and rate the cost drivers that act as the largest
contributors to unit costs, and to provide a focus for future cost reduction activities for the
Additive Manufacturing (AM) technology. A better understanding of the cost structure will
help to compare the AM costs with the opportunity costs of the classical manufacturing
technologies and will make it easier to justify the use of AM manufactured parts. This paper
will present work in progress and methodology based on a sample investigated with business
process analysis / simulation and activity based costing. In addition, cost drivers associated
with metal AM process will be rated.",,,,,,
"['Yang, Zhuo', 'Lu, Yan', 'Lane, Brandon', 'Kim, Jaehyuk', 'Ndiaye, Yande', 'Krishnamruty, Sundar']",2021-12-01T22:32:45Z,2021-12-01T22:32:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90640', 'http://dx.doi.org/10.26153/tsw/17559']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['remelting conditions', 'melt pool monitoring', 'data fusion', 'overhang build', 'powder bed fusion']",Analyzing Remelting Conditions based on In-Situ Melt Pool Data Fusion for Overhang Building in Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fcd09475-e9b1-4fe3-a93b-c67017633e90/download,University of Texas at Austin,"Coaxial melt pool monitoring (MPM) images provide in-depth insights into the building process of laser
powder bed fusion additive manufacturing. An in-situ MPM image captures the independent melting condition
at specific positions within each build layer. However, identifying material defects such as horizontal lack-of-fusion using individual, discontinuous MPM images poses multiple challenges. This paper builds upon the
authors’ previous work on data registration and data fusion to analyze material remelting conditions based on
co-axial MPM images. MPM data are fused to formulate layerwise remelting ‘maps’ to evaluate printing
quality. A 3D part with various overhang features was built to verify the method. A regular layer with solid
support from the previous layers has around 30 % remelting ratio for the given laser scan conditions. In
contrast, overhang regions remelted at about 10 % with the same process setting, whichis too low to provide
sufficient material fusion, resulting in lack-of-fusion between melting tracks. The negative impact in
remelting would not immediately disappear in subsequent layers following the overhang regions. Results
shows three additional layers are required to fully recover the remelting condition back to normal. The
remelting results from MPM are also visible within layerwise optical images of the same surface.",,,,,,
"['de Smit, Bram', 'Broek, Han J.']",2020-02-17T14:42:54Z,2020-02-17T14:42:54Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79999', 'http://dx.doi.org/10.26153/tsw/7024']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Extruded Polystyrene Foam,Analyzing the Cutting Process of a Heated Flexible Blade in Extruded Polystyrene Foam,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9eeff267-8a09-4c50-9f58-f6b46bcc52b7/download,,"For the “Free Form Thick Layered Object Manufacturing” technology that is being
developed at the Delft University, it is vital that Extruded Polystyrene Foam (XPS) can be cut
accurately with a heated blade. The shape of the blade is actively controlled during the cutting
process, which results in double curved cutting surfaces. In order to make this cutting process
controllable it must be known how the cutting behavior is under varying conditions, like cutting
speed, cutting angle and heating power. The authors executed a range of experiments, analyzed
the results and describe a practical model for the cutting process of XPS with a heated blade.",,,,,,
"['Niebling, F.', 'Otto, A.', 'Geiger, M.']",2019-10-24T17:54:50Z,2019-10-24T17:54:50Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77409', 'http://dx.doi.org/10.26153/tsw/4498']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Macroscopic,Analyzing the DMLS Process by a Macroscopic FE-Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8be69f88-0c09-4d79-a0d5-a8526a6a0722/download,,"The presented macroscopic FE-model allows to analyze the thermal fields and the
resulting stress built up during Selective Laser Sintering. Process and material parameters are
focused on Direct Metal Laser Sintering (DMLS). The FE-model is introduced and the
assumptions for the model are given. Three different geometric models are discussed. The 3Dmodel shows the sintering of a single line, whereas 2D-models are used for longitudinal and
crosscuts of the sintering process. Aim of the investigation is a more basic knowledge about the
process, which will lead to a stabilization and optimization of the process.",These investigations were financially supported by the DFG.,,,,,
"['Hernandez, R.', 'Slaughter, D.', 'Whaley, D.', 'Tate, J.', 'Asiabanpour, B.']",2021-10-28T14:15:19Z,2021-10-28T14:15:19Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89645,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['tensile properties', 'compressive properties', 'flexural properties', 'ABS plastics', 'P430', '3D printing', 'printing orientation', 'fused deposition modeling']","Analyzing the Tensile, Compressive, and Flexural Properties of 3D Printed Abs P430 Plastic Based on Printing Orientation Using Fused Deposition Modeling",Conference paper,https://repositories.lib.utexas.edu//bitstreams/83296808-1f7d-4da6-9578-a5c0f923cecb/download,University of Texas at Austin,"To achieve the optimum functionality and mechanical properties in the AM-based parts, it is
vital to fully characterize parts under static mechanical loadings (tension, compression, and
flexure) that are built in different orientations. This research reports the results of the
compression (ASTM standard D695), 4-point flexure (ASTM D790), and tensile (ASTM D 638
Type I) tests on the ABS plastic specimens that are designed according to the ASTM standards
and are built in different orientations using the uPrint SE Plus 3D printer. This study examined
the effects that printing 3D parts in different orientations (build angles) has on the mechanical
properties of ABS P430 plastic. A total of 45 samples (15 tension, 15 compression, and 15
flexure) were printed in 5 orientations; 0 degrees in the XY plane, 45 degrees in the XY plane,
90 degrees in the XY plane, 45 degrees in the Z plane, and 90 degrees in the Z plane. The
hypothesis was that the samples printed 0 degrees in the XY plane would be the strongest in
compression and flexure, and also have the greatest modulus of elasticity. The samples printed
90 degrees in the XY plane were predicted to be the strongest in tension, having the largest
tensile strength and lowest modulus of elasticity. The findings showed that printing 90 degrees in
the XY plane resulted in the highest tensile strength compared to the other orientations, but not
by a significant margin. Printing 0 degrees in the XY plane significantly increased the
compressive and flexure strengths of the material compared to other orientations.",,,,,,
"['Jiang, T.', 'Lin, F.', 'Kaltman, Steven I.', 'Sun, W.']",2019-09-23T17:25:05Z,2019-09-23T17:25:05Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75983', 'http://dx.doi.org/10.26153/tsw/3082']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Reconstruction,Anatomical Modeling and Rapid Prototyping Assisted Surgical Reconstruction 555,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a11940a-c8c4-446e-b2f2-3bdb686ecfaa/download,,"A CAD-based approach to generate three-dimensional anatomical modeling and its application in analysis and rapid prototyping for surgical reconstruction is presented. The process of modeling technique, starting from processing computed tomography segmentation profiles, reverse engineering to reconstruct 3D anatomical model, and rapid prototyping to fabricate physical models are described. Methods of applying the least-square fitting criteria to simplify CT or MRI anatomical data, to generate NURBS based curves, surfaces, and solids, and to develop a CAD-based anatomical modeling for femur are introduced.
Feasibility of using finite element method for femur structural analysis and using rapid prototyping to reproduce tactical medical model for surgical reconstruction is also discussed.","We gratefully acknowledge the support from NSF 9980298 project funding to graduate student T.
Jiang during the course of this research.",,,,,
"['Conway, Kaitlynn M.', 'Romanick, Zachary', 'Cook, Lea M.', 'Morales, Luis A.', 'Despeaux, Jonathan D.', 'Ridlehuber, Marcus L.', 'Fingar, Christian', 'Doctor, Daquan', 'Pataky, Garrett J.']",2021-11-30T22:26:39Z,2021-11-30T22:26:39Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90570', 'http://dx.doi.org/10.26153/tsw/17489']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['cellular materials', 'anisotropy', 'yield envelope']",The Anisotropic Yield Surface of Cellular Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08e4611c-24d8-43aa-ad5f-1030ce8d2045/download,University of Texas at Austin,"Mechanical metamaterials are often limited in engineering applications because of uncertainty in
their deformation behavior. This uncertainty necessitates large factors of safety and behavior
assumptions to be included in mechanical metamaterial designs, detracting from the largest
benefit of metamaterials: their ultralight weight. In this study, a yield envelope was created for
both a bending dominated and a stretching dominated cellular material topology to improve the
understanding of the response of cellular materials under various load types and orientations.
Experimental studies revealed that the shear strength of a cellular material is significantly less
than that predicted by the Mohr’s criterion, necessitating a modification of the Mohr’s yield
criterion for cellular materials. Both topologies experienced tension-compression anisotropy and
anisotropy dependent on the topology orientation during loading with the stretching dominated
topology experiencing the largest anisotropies.",,,,,,
"['Kamatchi Subramanian, P.', 'Vail, N.K.', 'Barlow, J.W.', 'Marcus, H.L.']",2018-10-03T16:55:21Z,2018-10-03T16:55:21Z,1994,Mechanical Engineering,doi:10.15781/T29Z90X3G,http://hdl.handle.net/2152/68667,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['alumina powders', 'selective laser sintering', 'copolymer']",Anisotropy in Alumina Processed by SLS.,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1cf8e989-c83f-4525-8e81-ac02ddda3ef0/download,,"Alumina powders of 15~m size and 2~m size were processed by SLS using PMMA and a
copolymer. The 2~m powders were agglomerated and mixed with the polymer powder before
being processed by SLS. SLS bend strength specimens were made with parts built along
different orientations. The variation of the strength with incident energy density and with
orientation was studied.",,,,,,
"['Munguia, J.', 'Dalgarno, K.W.']",2021-10-11T22:41:55Z,2021-10-11T22:41:55Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88672', 'http://dx.doi.org/10.26153/tsw/15606']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Ankle-Foot-Orthoses', 'composite reinforncement', 'thermoforming polymer sheets']",Ankle Foot Orthotics Optimization by Means of Composite Reinforcement of Free-Form Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c37847b4-6714-456b-82c9-780231f6f23c/download,University of Texas at Austin,"Ankle-Foot-Orthoses (AFOs) are assistive devices prescribed for a number of physical and
neurological disorders affecting the mobility of the lower limbs. Traditional AFO design is
based on thermoforming polymer sheets around a plaster cast with a characteristic stiffness
depending on the selected trim-line with the inherent design limitations. Additive
Manufacturing has been explored as an alternative process; however it has proved to be
inefficient cost-wise. This work explores the possibilities of generating modular AFO
elements: calf, shank, and footplate with localized composite reinforcement that aids in the
optimization of the device in terms of functionality, aesthetics, rigidity and cost.",,,,,,
"['Dehghan-Niri, E.', 'Hespeler, S.C.', 'Juhasz, M.', 'Halliday, H.S.', 'Lang, M.']",2023-04-03T17:47:53Z,2023-04-03T17:47:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117730', 'http://dx.doi.org/10.26153/tsw/44609']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Anomal Detection for In-situ Quality Control of Directed Energy Deposition (DED) Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9448763b-3492-4d02-8e4c-5d01554d5a3b/download,,"One common cause for the rejection of parts produced during metal Additive 
Manufacturing (AM) is the presence of unacceptable defects within the part. While 
powerful, post-processing nondestructive techniques can be unapproachable due to time 
constraints or simply impractical for certain inspection and quality control applications of 
the AM, especially with parts of high complexity. The AM process requires a layer-by-
layer execution to build parts, allowing for a unique opportunity to collect data and monitor 
the process in real/semi-time. The incipient phase of AM monitoring and control typically 
consists of developing an automated unsupervised statistical anomaly detection 
algorithm that is capable of detecting irregularities through parameter measurement and 
sensing features. In this paper, we develop a simple and effective method for detecting 
anomalies through use of statistical distances from data collected during the laser-based 
Directed Energy Deposition (DED) AM process.",,,,,,
"['Prakash, Sashikanth', 'Boddu, Mallikharjuna Rao', 'Liou, Frank']",2019-11-20T16:35:29Z,2019-11-20T16:35:29Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78476', 'http://dx.doi.org/10.26153/tsw/5561']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Diagnostic Tool,Application of a Diagnostic Tool in Laser Aided Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e336f304-4b83-4aa6-9d63-87969a6e5a0d/download,,"Lasers play a vital role in producing parts with high dimensional accuracy, strength and
quality in today's rapid prototyping industry. In the process of Laser Metal Deposition, many
problems are encountered where the part quality does not meet the required standards. This could
be due to the nonconformity of control parameters or unnecessary interactions between the
control factors. This paper discusses the implementation of Dr. Genichi Taguchi’s optimization
techniques using Design of Experiments (DOE) where a series of fractional factorial experiments
are performed on the laser deposition process. The results from these experiments are evaluated
with respect to the rate of deposition alongside the part quality and the optimized level setting of
control parameters are determined efficiently. This tool can be used to detect and diagnose flaws
and discrepancies in the Laser Metal Deposition process and optimize it accordingly.","This research was supported by the National Science Foundation Grant Number
DMI-9871185, Missouri Research Board, and Army Research Office. Their support is gratefully
appreciated.",,,,,
"['Loughnane, Gregory T.', 'Kuntz, Sarah L.', 'Klingbeil, Nathan', 'Sosa, John M.', 'Irwin, Jeff', 'Nassar, Abdalla R.', 'Reutzel, Edward W.']",2021-10-20T21:31:26Z,2021-10-20T21:31:26Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89366,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Laser Engineered Net Shaping', 'Widmanstätten ⍺-lath', 'wall thickness', 'uncertainty quantification', 'Ti-6Al-4V']",Application of a Microstructural Characterization Uncertainty Quantification Framework to Widmanstätten ⍺-laths in Additive Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7c32e9c9-c76a-4e1e-8906-a50862f45d99/download,University of Texas at Austin,"This work applies statistical analysis and uncertainty quantification tools developed for
characterizing virtual microstructures in three dimensions to a two-dimensional experimental
investigation of Ti-6Al-4V Widmanstätten ⍺-lath thicknesses obtained from back-scattered
electron (BSE) or electron back-scatter diffraction (EBSD) images on two thin-walled samples
manufactured via the LENS® process. The Materials Image Processing and Automated
Reconstruction (MIPAR™) software optimizes unique recipes for conversion of the BSE or
EBSD images to binary data, and subsequently computes the inverse of the linear intercept for
each ⍺-lath. Mean ⍺-lath thicknesses and discrete probability density functions (PDFs) of
inverse intercepts are used to make quantitative comparisons of ⍺-lath structures at different
heights throughout the thin walls. Real-time thermal data collected during the LENS®
experiment is then compared to quantitative microstructural results in order to determine trends
between ⍺-lath structures, thermal gradients, and melt pool areas across experimental process
parameters.",,,,,,
"['Melvin, Lawrence S. III', 'Beaman, J.J.']",2018-04-19T17:10:13Z,2018-04-19T17:10:13Z,1992,Mechanical Engineering,doi:10.15781/T2Z31P56K,http://hdl.handle.net/2152/64386,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'microgravity', 'Department of Mechanical Engineering', 'magnetostatic system']",The Application of an Artificial Body Force to the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/da3efd8a-1c18-4529-8137-3c48c4ae247b/download,,"An artificial body force generated by a magnetic
field is applied to the green powder bed of a ferromagnetic
powder during the Selective Laser Sintering process.
Preliminary experiments and theory are formed to
determine whether the artificial body force is beneficial to
the Selective Laser Sintering process and if it is usable
within that process. Several applications are discussed
including microgravity situations and two phase sintering
processes. It is determined that the magnetic body force is
beneficial to the Selective Laser Sintering process.",,,,,,
"Pegna, Joseph",2018-10-03T20:19:41Z,2018-10-03T20:19:41Z,1995,Mechanical Engineering,doi:10.15781/T2M902N5H,http://hdl.handle.net/2152/68688,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['functional prototypes', 'multimodal structures', 'construction automation']",Application of Cementitious Bulk Materials to Site Processed Solid Freeform Construction,Conference paper,https://repositories.lib.utexas.edu//bitstreams/615cbbec-7f69-424a-9865-8e25860b693c/download,,"This paper reports a radical departure from generally accepted concepts in construction
automation and demonstrates that new techniques of layered manufacturing can be applied
effectively to construction. In the process, we also modified material processing of cement to
adapt it to the requirements ofSolid Freeform Fabrication.
Our purpose is illustrated with sample structures manufactured by incremental deposition of
reactive bulk materials (cement and Silica in this instance), a characterization of their material
properties, and an assessment of their potential for Solid Freeform Fabrication of large structures.
For example, we estimated that it would take about months to build a structure the size
ofa 3000 sq. ft. house.",,,,,,
"['Bitar, Isam S.', 'Aboulkhair, Nesma T.', 'Leach, Richard']",2021-11-02T19:11:49Z,2021-11-02T19:11:49Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89868,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['carbon fiber', 'through thickness', 'composite', 'mechanical behavior', 'additive manufacture']",The Application of Composite Through-Thickness Assessment to Additively Manufactured Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8257f635-2b40-404b-a4be-29c897d70199/download,University of Texas at Austin,"This study looks into the applicability of through-thickness assessment to additive
manufacturing (AM) carbon-fibre reinforced polymers (CFRPs). The study utilised a material
extrusion printer that uses fused filament fabrication and composite filament fabrication
technologies to manufacture functionally-graded polymer and composite polymer parts. The
matrix material of choice was nylon 6. Samples were printed exploring a range of
reinforcement volume content. In summary, this study presents an assessment of the
applicability of through-thickness testing to AM CFRP specimens and provides a performance
comparison between AM composite through-thickness properties and the properties of
equivalent CM CFRP specimens.",,,,,,
"['Weinmann, J.', 'Ip, H.', 'Prigozhin, D.', 'Escobar, E.', 'Mendelson, M.', 'Noorani, R.']",2019-11-20T16:55:05Z,2019-11-20T16:55:05Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78484', 'http://dx.doi.org/10.26153/tsw/5569']",eng,2003 International Solid Freeform Fabrication Symposium,Open,RapidPrototyped,Application of Design of Experiments (DOE) on the Processing of Rapid Prototyped Samples,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf67d8aa-effb-42d8-b1de-aca241ddae31/download,,"The purpose of this experiment was to improve the Fused Deposition Modeling Process by
examining the tensile strength of samples fabricated in a Stratasys FDM 1650 Machine utilizing
the methods of Design of Experiments. A two-level, four-factor, full factorial experiment was
conducted. The selected factors were temperature, air gap, slice thickness, and raster orientation.
A regression equation determined the level each factor should be set in order to optimize the
FDM machine settings. It was found that single factors - small air gap, small layer thickness
and low raster orientation, as well as the interaction between high temperature and small layer
thickness yielded the greatest effect the response.",,,,,,
"['Walish, J.', 'Sutaria, M.', 'Dougherty, M.', 'Vaidyanathan, R.', 'Kasichainula, S.', 'Calvert, P.']",2019-03-11T16:36:53Z,2019-03-11T16:36:53Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73581', 'http://dx.doi.org/10.26153/tsw/723']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['silicon nitride powders', 'DOE']",Application of Design of Experiments to Extrusion Freeform Fabrication (EFF) of Functional Ceramic Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2bf9343d-8a42-4a45-a09c-1cc5ace2471a/download,,"Extrusion Freeform Fabrication (EFF) is an adaptation of the Stratasys Fused Deposition
Modeling (FDM) process for the Solid Freeform Fabrication (SFF) of functional ceramic
prototypes. It is a complex process involving many process variables, including parameters that
are operation, machine, materials, and geometry specific. A Taguchi factorial Design of
Experiments (DOE) technique was utilized to study the effects of machine specific process
parameters as well as their interactions based on the mechanical and physical properties of
sintered ceramics specimens. Post-processing software was developed to control and modify these
parameters. This software interface wasdesigned to mimic the Quickslice™ interface for setting
motion parameters based upon the material and the operation. The results of this investigation
provided useful information for the experimental analysis of the machine specific process
parameters. Suitable parameters were selected for the EFF process for fabricating representative
ceramic prototypes. With the optimized parameters, complicated parts were successfully
fabricated using both Kyocera SN282 and Starck M-11 silicon nitride powders.",,,,,,
"['Deng, Xioaming', 'Beaman, Joseph J.']",2018-04-19T17:54:23Z,2018-04-19T17:54:23Z,1992,Mechanical Engineering,doi:10.15781/T2X34N85V,http://hdl.handle.net/2152/64394,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'Department of Mechanical Engineering', 'sintering geometry']",Application of Factorial Design in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fe9c566f-307c-491e-9118-d755f46708b9/download,,"Selective Laser Sintering (SLS) is a complex process involving many process parameters.
These parameters are not all independent. A factorial design technique is utilized to study the
effects of three main process parameters, laser power, laser beam scanning speed, and powder
packing density as well as their interactions on the sintering depth and fractional density. The
results of this investigation provide useful information for the further experimental analysis of
the process parameters and for selecting suitable parameters for SLS process.",,,,,,
"['Konig, Oliver', 'Fadel, Georges M.']",2019-03-12T16:41:02Z,2019-03-12T16:41:02Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73599', 'http://dx.doi.org/10.26153/tsw/741']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['FE""\'analysis', 'DOF']",Application of Genetic Algorithms in the Design of Multi-Material Structures Manufactured in Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/291ae70f-08c4-4f8d-b4c7-92faa047deea/download,,"Recent developments in the Rapid Prototyping technology establish it as a new
manufacturing technique, enabling localized material addition to build a part. Thus,
heterogeneous structures, consisting of more than one material can be produced. The aim of this
paper is to present an optimization tool to find the best material distribution in a multi-material
structure due to given objectives and constraints. The tool is based on genetic algorithms using a
discrete material model and FE""'analysis to evaluate the objective functions. It can optimize the
distribution materials in 2D-structures with up to 1500 DOF's at reasonable
computational costs. Its performance is shown on a bi-objective optimization of a turbine blade.",,,,,,
"['Ouyang, J.H.', 'Mei, H.', 'Valant, M.', 'Kovacevic, R.']",2019-10-22T18:00:05Z,2019-10-22T18:00:05Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76327', 'http://dx.doi.org/10.26153/tsw/3416']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Welding,Application of Laser-Based Additive Manufacturing to Production of Tools for Friction Stir Welding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91806466-1b99-4271-88d2-92922407539c/download,,"This paper presents a feasibility study of application of laser-based additive
manufacturing to production of tools for friction-stir welding (FSW) of materials. The design
and rapid manufacturing of powerful tools has become one of the major challenges in expanding
the application of FSW processes to new materials. The one-step laser cladding process is
capable of creating a novel, fully dense and metallurgically bonded near-net-shape tool with
microstructural and compositional gradients. In this paper, two kinds of FSW-tool materials are
developed and evaluated for the applications of welding different materials. A pure H13 tool
steel powder is used to build a FSW-tool for welding the materials with relatively low melting
temperatures, such as aluminum alloys. A WC-based ceramet/tool steel functionally graded
material (FGM) is synthesized to build a FSW-tool in order to weld the materials with higher
melting temperatures and highly abrasive materials such as MMC materials. By controlling the
amount of different supplied powders under the optimized laser cladding conditions, WC-based
ceramet/tool steel FGMs are successfully synthesized layer by layer. FSW experiments are
carried out to evaluate the deposited tools.","This work was financially supported by THECB, Grants 003613-0022-1999, 003613-
0016-2001, NSF Grants No. DMI-9732848 and DMI-9809198, and the U.S. Department of
Education, Grant No. P200A80806-98.",,,,,
"['Malone, Evan', 'Purwin, Oliver']",2020-02-13T21:02:36Z,2020-02-13T21:02:36Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79979', 'http://dx.doi.org/10.26153/tsw/7004']",eng,2004 International Solid Freeform Fabrication Symposium,Open,viscosity,Application of Machine Learning Methods to the Open-Loop Control of a Freeform Fabrication System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0605853-f5c0-4975-97fc-4e35567e1659/download,,"Freeform fabrication of complete functional devices requires the fabrication system to achieve well-controlled
deposition of many materials with widely varying material properties. In a research setting, material preparation
processes are not highly refined, causing batch property variation, and cost and time may prohibit accurate
quantification of the relevant material properties, such as viscosity, elasticity, etc. for each batch. Closed-loop
control based on the deposited material road is problematic due to the difficulty in non-contact measurement of the
road geometry, so a labor-intensive calibration and open-loop control method is typically used. In the present work,
k-Nearest Neighbor and Support Vector Machine (SVM) machine learning algorithms are applied to the problem of
generating open-loop control parameters which produce desired deposited material road geometry from a description
of a given material and tool configuration comprising a set of qualitative and quantitative attributes. Training data
for the algorithms is generated in the course of ordinary use of the SFF system as the results of manual calibration of
control parameters. Given the large instance space and the small training data set compiled thus far, the
performance is quite promising, although still insufficient to allow complete automation of the calibration process.
The SVM-based approach produces tolerable results when tested with materials not in the training data set. When
control parameters produced by the learning algorithms are used as a starting point for manual calibration,
significant operator time savings and material waste reduction may be achieved.",,,,,,
"['Hasan, S.', 'Rennie, A.E.W.']",2021-09-23T22:45:10Z,2021-09-23T22:45:10Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/88044', 'http://dx.doi.org/10.26153/tsw/14985']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Rapid Manufacturing', 'spare parts industry', 'e-business']",The Application of Rapid Manufacturing Technologies in the Spare Parts Industry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08d8f05a-05c0-4aa6-910e-7fa8aeec1020/download,,,,text,,,,
"['Bharadwaja, R.', 'Murugan, Aravind', 'Chen, Yitao', 'Liou, F W']",2021-11-18T18:26:50Z,2021-11-18T18:26:50Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90457', 'http://dx.doi.org/10.26153/tsw/17378']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['schlieren', 'visualization', 'shielding gas', 'additive manufacturing']",Application of Schlieren Technique in Additive Manufacturing: A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6765b25-515a-4723-8c53-66123153de35/download,University of Texas at Austin,"Additive manufacturing has gained a lot of attention in the past few decades due to its
significant advantages in terms of design freedom, lower lead time, and ability to produce complex
shapes. One of the pivotal factors affecting the process stability and hence the part quality is the
shielding gas flow in additive manufacturing. As extremely beneficial for the process, the shielding
gas flow is often set at maximum supply to achieve enough gas cover over the substrate. This
causes excessive quantity of shielding gas to be unutilized. Realizing the importance of shielding
gas, various studies have been carried out to monitor and visualize the shielding gas, and one such
technique is Schlieren imaging. Schlieren visualization has been used since the 1800s as a powerful
visualization tool to visualize fluctuations in optical density. The Schlieren technique is highly
effective for visualizing and optimizing shielding gas flow. This paper aims to provide an overview
of Schlieren technique used for visualization of shielding gas and highlights the application of
Schlieren in additive manufacturing.",,,,,,
"['Harryson, Ola', 'Cormier, Denis', 'Marcellin-Little, Denis', 'Jaja, Ketan']",2019-10-22T17:36:22Z,2019-10-22T17:36:22Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76322', 'http://dx.doi.org/10.26153/tsw/3411']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Preoperative Pllanning,Application of SFF to Preoperative Planning and Surgical Rehearsal for Treatment of Limb Deformities in Dogs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eeb250cc-9bf1-47b5-b400-9b79cae2bd1a/download,,"This report describes SFF-aided assessment and preoperative planning for treatment of
bilateral multifocal pelvic limb deformities in a one-year old German Shepherd dog. CT scans
were converted to solid models and stereolithography patterns were prototyped. RTV silicone
molds were constructed and three sets of polyurethane patterns were cast for pre-surgical
rehearsal. The paper compares traditional osteotomy planning procedures, planning via virtual
prototypes, and planning with full-scale physical prototypes.",,,,,,
"['Kinsella, M.E.', 'Lilly, B.W.', 'Bhagavatula, N.', 'Cooper, K.G.']",2019-10-22T18:07:57Z,2019-10-22T18:07:57Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76330', 'http://dx.doi.org/10.26153/tsw/3419']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Quantities,Application of Solid Freeform Fabrication Processes for Injection Molding Low Production Quantities: Process Parameters and Ejection Force Requirements for SLS Inserts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8acf9c49-e28c-4c8b-8d95-d5068e419d12/download,,"Studies are underway for the application of solid freeform fabrication processes for mold
inserts to be used in thermoplastic injection molding of low quantities of parts. This work
initially compares a laser sintered insert (LaserForm™ ST-100) with a steel insert. Models and
experiments determine process parameters, including molding latitude, and ejection force
requirements. Ejection force predictions are based on work by Menges, using values for elastic
modulus determined from tensile tests at ejection temperatures. Similar studies are planned for
stereolithography inserts (SL 5170).",,,,,,
"['Jayanthi, Suresh', 'Harwin, William', 'Keefe, Michael', 'Kumar, Vijay']",2018-11-02T16:16:03Z,2018-11-02T16:16:03Z,1995,Mechanical Engineering,doi:10.15781/T21R6NK6M,http://hdl.handle.net/2152/69334,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'cerebral palsy', 'rehabilitation engineering']",Application of Stereolithography in the Fabrication of Rehabilitation Aids,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e00c1557-6072-4ac7-aeaf-9b1265e927e3/download,,"Free form fabrication methods have a great potential to significantly
improve the design and manufacture of equipment for people
with physical disabilities, such as quadriplegia through spinal cord injury,
arthrogryposis, or cerebral palsy. Depending on the nature of
the disability a device may need to be designed or adapted. A person
with quadriplegia, for example, may benefit from an assistive device
that maps existing head movements, into the movements of a spoon
between a plate and his/her mouth. To be comfortable and effective
a person Iuay need a headband that can connect to a suitable linkage.
Stereolithography lends itself well to the fabrication of such one-of-akind
devices. Since the fabrication process time is considerably less
than conventional approaches a greater number of iterations can be
performed during the design to arrive at the most compatible device
for a particular disability. Some rehabilitation devices are fabricated
to establish the viability and linlitations of this approach. This paper
details the efforts underway to integrate stereolithography with the
needs of rehabilitation engineering.",,,,,,
"['Fisher, Joseph W.', 'Simpson, Timothy W.', 'Miller, Simon W.']",2023-03-01T17:15:32Z,2023-03-01T17:15:32Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117548', 'http://dx.doi.org/10.26153/tsw/44428']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Lattice  Structure,Application of Systems Engineering to Lattice Structure Design: A Framework for Requirements Flow Down,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2516141b-ebf3-47e3-aa00-bc4446fccb65/download,,"In the field of additive manufacturing, highly ordered cellular structures with repeating
patterns in space, known as lattice structures or simply “lattices”, have been shown to sig-
nificantly improve the performance per unit mass of engineered components compared to
traditionally machined designs. The characteristics of these lattices are dependent on many
design decisions, leading to challenges in determining how to best utilize them. This issue
is further complicated when the density, size, and topology of the lattice can spatially vary
in the design domain. Many methods have been proposed to optimally distribute material
within a lattice structure; however, these methods exist in a bubble, independent of broader
engineering design criteria and processes. In this paper, we introduce a framework based on
systems engineering to guide the design of lattice structures using the component requirements
as inputs and outputting a verified and validated design based on those requirements. The
framework translates component requirements down to the lattice structure and provides a
means to verify and validate that the final design meets those requirements. We provide a
walk-through of the framework by designing a lattice structure for an oil and gas component,
and discuss future research to extend, verify, and validate the framework.",,,,,,
"['Adnan, Muhammad', 'Lu, Yan', 'Jones, Al', 'Cheng, Fan Tien']",2021-11-16T16:25:11Z,2021-11-16T16:25:11Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90334', 'http://dx.doi.org/10.26153/tsw/17255']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fog computing', 'monitoring & control', 'functional architecture', 'control architecture', 'data analytics']",Application of the Fog Computing Paradigm to Additive Manufacturing Process Monitoring and Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d04ea32-cba5-4730-ba23-e3603beabaf8/download,University of Texas at Austin,"Monitoring and controlling Additive Manufacturing (AM) processes play a critical role in
enabling the production of quality parts. AM processes generate large volumes of structured and
unstructured in-situ measurement data. The ability to analyze this volume and variety of data in
real-time is necessary for effective closed-loop control and decision-making. Existing control
architectures are unable to handle this level of data volume and speed. This paper investigates the
functional and computational requirements for real-time closed-loop AM process control. The
paper uses those requirements to propose a function architecture for AM process monitoring and
control. That architecture leads to a fog-computing solution to address the big data and real-time
control challenges.",,,,,,
"['Chahine, Gilbert', 'Smith, Pauline', 'Kovacevic, Radovan']",2021-09-30T19:14:49Z,2021-09-30T19:14:49Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88284', 'http://dx.doi.org/10.26153/tsw/15225']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'modern additive manufacturing', 'Electron Beam Melting', 'functionally graded porosity', 'bio-adaptable dental implants']",Application of Topology Optimization in Modern Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/350d3d4c-51e8-48a0-9556-0af9dbbf25e7/download,University of Texas at Austin,"The current work examines the principle of topology optimization (TOP) and solving the problem
of minimal compliance, and its applications in modern additive manufacturing (AM). The theory of TOP
has been excessively investigated for the past few decades; however its practical use is hindered by
manufacturing limitations of manifesting the designs into physical parts. TOP numerically determines the
favorable topology configuration contained in a workspace that is constrained by a specific set of
external supports and applied loads. It overcomes conventional design traditions, and solves for finding
the path of least resistance, mimicking phenomenon found in natural structures, such as bone and wood.
The present research focuses on the different methodologies invested in the field, and also inspects the
possibilities and efficiency of using numerical design, which is powered by TOP, in modern AM processes
such as Electron Beam Melting enabling the production of highly complex parts. The major interest is the
production of functionally graded porosity (FGP) in bio-adaptable dental implants able to reduce stress
shielding, promote faster osseointegration, and provide micromotion between the dental prosthesis and
the root form of the implant. Future implications of the field include optimized porous structures aiming
towards application-defined stiffness and pore size, enabling a digital design with advances analogous to
modern AM.",,,,,,
"Winkelman, Wayne",2018-10-03T16:45:46Z,2018-10-03T16:45:46Z,1994,Mechanical Engineering,doi:10.15781/T2V11W50J,http://hdl.handle.net/2152/68663,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['CAD/CAM', '3D digitized data', 'reverse engineering']",Applications of 3D Laser Digitizing and Surfacing Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ad3ba3c-d02a-4c16-ae04-e78b0e77fd73/download,,,,,,,,
"['Mohammed, Mazher I.', 'Tatineni, Joseph', 'Cadd, Brenton', 'Peart, Greg', 'Gibson, Ian']",2021-10-28T21:43:23Z,2021-10-28T21:43:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89708,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['prosthesis', '3D printing', 'modelling', 'multi-material', 'soft tissue']",Applications of 3D Topography Scanning and Multi-Material Additive Manufacturing for Facial Prosthesis Development and Production,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e7c23dcc-8e62-4c68-9caf-737904a6565e/download,University of Texas at Austin,"Prosthetic based rehabilitation offers several advantages over surgical intervention,
however, devices are generally handmade using labour intensive and subjective manufacturing
techniques. We investigate the use of optical scanning to capture the surface topography from
a volunteer’s facial anatomy, reconstruct this into a 3D CAD model, and from that design a
patient specific prosthesis. This approach offers many advantages over existing techniques as
data collection is non-intrusive, rapid and provides anatomically precise information. A CAD
approach affords greater flexibility when evaluating design iterations and allows for the
creation of ‘parts libraries’ for use with patients with no initial reference anatomy. The final
prosthesis is realised through high resolution, multi-material 3D printing for precise model
reproduction and to add functionalities such as mimicry of soft and hard tissues. Ultimately,
we believe our approach provides an optimised, low-cost approach for streamlining the
complete methodology for prosthesis production.",,,,,,
"['Liou, Frank', 'Slattery, Kevin', 'Kinsella, Mary', 'Newkirk, Joseph', 'Chou, Hsin-Nan', 'Landers, Robert']",2020-02-27T19:14:59Z,2020-02-27T19:14:59Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80092', 'http://dx.doi.org/10.26153/tsw/7113']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Rapid Prototyping,Applications of a Hybrid Manufacturing Process for Fabrication and Repair of Metallic Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/adef9ef7-1ac2-4e5b-926b-c9b17f714025/download,,"Since its appearance, rapid prototyping technology has been of interest to various industries that
are looking for a process to produce/build a part directly from a CAD model in a short time.
Among them, the direct metal deposition process is the only process which directly manufactures
a fully dense metal part without intermediate steps. However, challenges of the direct metal
deposition process include building overhang structures, producing precision surfaces, and
making parts with complex structures. Coupled between the additive and the subtractive
processes into a single workstation, the integrated process, or hybrid process, can produce a
metal part with machining accuracy and surface finish. Therefore, the hybrid process is
potentially a very competitive process to fabricate and repair metallic structures. This paper
summarizes the current development of the hybrid process to process high temperature metallic
materials, including tool steel and Ti64. Research in simulation and modeling, process
development, and actual part building and repair are discussed.",,,,,,
"['Isanaka, Sriram Praneeth', 'Liou, Frank']",2021-10-05T19:23:30Z,2021-10-05T19:23:30Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88416', 'http://dx.doi.org/10.26153/tsw/15355']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Cyber Enabled Manufacturing', 'additive manufacturing technology', 'cyber-physical systems']",The Applications of Additive Manufacturing Technologies in Cyber-Enabled Manufacturing Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0cc996d3-09c5-422f-b222-c811d46fe2dc/download,University of Texas at Austin,"The application of networked sensors and control in various areas, such as smart grids
and infrastructures, has become a recent trend, called cyber-physical systems. The Cyber
Enabled Manufacturing (CEM) environment is to apply these technologies in manufacturing
systems to handle a significantly greater magnitude of manufacturing data. Additive
manufacturing techniques print or place material layer by layer to form a part, thus have a great
potential to help accelerate CEM process by printing or embedding sensors and actuators in the
proper locations. This paper summarizes the roles of additive manufacturing technologies to help
establish a CEM environment.",,,,,,
"['Wohlert, Martin', 'Bourell, David L.', 'Das, Suman', 'Beaman, Joseph J.']",2019-09-23T15:19:57Z,2019-09-23T15:19:57Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75933', 'http://dx.doi.org/10.26153/tsw/3032']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Densification,Applications of Powder Densification Maps to Direct Metal SLS/HIP Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7a26921d-94f6-431e-9cad-8e900e9b5ba9/download,,"Recent investigations have shown that Direct Selective Laser Sintering in conjunction with Hot Isostatic Pressing (HIP) is capable of producing fully dense, near net shape, high performance metal components. A key aspect of this combined processing method is the selection of appropriate HIP process parameters to obtain full density parts. Powder Densification Maps
provide a powerful tool for predicting the effect of time, temperature, pressure, and material properties on part density. This paper summarizes developments in Powder Densification Map production for Ti-6Al-4V and Inconel 625 materials. A comparison of theoretically predicted and experimentally determined densities for a variety of processing conditions is presented.",,,,,,
"['Thomas, J.P.', 'Bender, B.A.', 'Pique, A.', 'Cooper, K.P.', 'Rayne, R.J.', 'Richardson, A.C.']",2019-10-18T17:07:55Z,2019-10-18T17:07:55Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76264', 'http://dx.doi.org/10.26153/tsw/3353']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Applications of Solid Freeform Fabrication at the Naval Research Laboratory,Conference paper,https://repositories.lib.utexas.edu//bitstreams/efeacd08-1d4d-4e9f-b064-b1ae3ab37769/download,,"Solid Freeform Fabrication (SFF) and related techniques are used at the Naval Research
Laboratory (NRL) for a variety of materials related investigations. Research and applications
conducted over the past few years are described including: Helisys Laminated Object
Manufacturing System (LOMS) fabrication of: ceramic piezoelectric actuators, tooling for
multifunctional materials, and anatomical prototypes for surgical visualization; fabrication of
mesoscale electronic and sensor components using a laser forward transfer direct write
technique; and visualization of complex, 3-D microstructures using a Stratasys Fused-Deposition
Modeler. The paper closes with a brief overview of future SFF related work at the NRL.","Support for this work from DARPA, Office of Naval Research, and the Naval Research
Laboratory Core Research Program is gratefully acknowledged.",,,,,
"['Joshi, M.S.', 'Flood, A.', 'Sparks, T.', 'Liou, F.W.']",2021-11-16T16:17:50Z,2021-11-16T16:17:50Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90331', 'http://dx.doi.org/10.26153/tsw/17252']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['supervised learning algorithms', 'support vector machines', 'random forests', 'machine learning', 'additive manufacturing']",Applications of Supervised Machine Learning Algorithms in Additive Manufacturing: A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5e84fc3-f039-4f3d-8f2c-503624c84bdd/download,University of Texas at Austin,"Additive Manufacturing (AM) simplifies the fabrication of complex geometries. Its scope
has rapidly expanded from the fabrication of pre-production visualization models to the
manufacturing of end use parts driving the need for better part quality assurance in the additively
manufactured parts. Machine learning (ML) is one of the promising techniques that can be used to
achieve this goal. Current research in this field includes the use of supervised and unsupervised
ML algorithms for quality control and prediction of mechanical properties of AM parts. This paper
explores the applications of supervised learning algorithms - Support Vector Machines and
Random Forests. Support vector machines provide high accuracy in classifying the data and is
used to decide whether the final parts have the desired properties. Random Forests consist of an
ensemble of decision trees capable of both classification and regression. This paper reviews the
implementation of both algorithms and analyzes the research carried out on their applications in
AM.",,,,,,
"['Wang, Jia-Chang', 'Dommati, Hitesh']",2021-11-08T23:06:34Z,2021-11-08T23:06:34Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90071', 'http://dx.doi.org/10.26153/tsw/16992']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['slurry based stereolithography', 'high performance ceramics', 'non-self-supporting structures', 'earrings']",Applied Solvent-Based Slurry Stereolithography Process to Fabricate High-Performance Ceramic Earrings with Exquisite Details,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b0feaeeb-9f43-4a34-9880-c01327f0149b/download,University of Texas at Austin,"This paper discusses the application of Slurry based Stereolithography additive
manufacturing process in the fabrication of complex earring models without any support structures
requirement, using High-Performance Ceramic (HPC) materials. The earring model chosen in this
study is a Rose flower with blossomed petals. The petals have edge thickness in microns and
extreme overhangs with a custom text and logo on the bottom. Using any other ceramic additive
manufacturing process, it requires support structures to build this model. The support removal in
such minute structures is not easy and not always successful. Using Solvent based Slurry
Stereolithography (3S) process, models with the micron details and overhangs can be easily built.
This is enabling the neat and clean post-processing procedure to maintain the exquisite details and
also gain high surface quality. The ceramic material used in this application is alumina. With some
additives, it will show in different colors like sapphire. The resultant flowers are vividly shown in
white, pink, green, and blue. In this study, it is also discussed about the slurry process,
Stereolithography system, and proven applications of the 3S process.",,,,,,
"['Emery, B.', 'Revier, D.L.', 'Lipton, J.I.']",2021-11-30T22:29:11Z,2021-11-30T22:29:11Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90571', 'http://dx.doi.org/10.26153/tsw/17490']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['foams', 'viscous thread instability', 'viscous thread printing', 'cellular structures']",Applied Viscous Thread Instability for Manufacturing 3D Printed Foams,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68ca81b3-d9cc-45a1-98be-9ecaf4b86819/download,University of Texas at Austin,"Traditional foams are fabricated via stochastic chemical processes that yield homogeneous
material properties. Foams can exhibit a wide range of material properties by varying process
controls allowing them to be used in many industrial and commercial applications. Previously,
additive manufacturing could only produce foam approximations in the form of traditional lattice
infill. Our work employs viscous thread printing (VTP) of thermoplastic polyurethane (TPU) on a
fused filament fabrication (FFF) printer, exploiting the semi-viscous nature of extruded filament
to coil producing a new type of printed foam. Specimens were tested under compression to
determine uniformity along principal axes and behavior under strain when compared to infill
patterns, such as grid and cubic. This work establishes that VTP as applied to TPU can be used to
manufacture programmable stiffness foams as a function of density, suited to a variety of needs
and should be considered as an alternative to traditional foams and other printed lattice geometries.",,,,,,
"['Chiu, Y. Y.', 'Chang, J. H.']",2020-02-17T14:30:03Z,2020-02-17T14:30:03Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79998', 'http://dx.doi.org/10.26153/tsw/7023']",eng,2004 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,The Approach of Complex Insert Packaging Fabrication in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d7975c96-ac7d-43e9-bba2-e52ad356cffd/download,,"The approach of complex insert packaging fabrication in stereolithography is studied in the
paper. There are many difficulties being overcome, such as the dispensing shadowing problem
caused by the geometric shape of insert, the polymer feeding problem caused by greater insert
height than the layer thickness, and the positioning problem of insert that leads to instability of
packaging. These drawbacks led to unsatisfactory results of the insert packaging in
stereolithography. In order to solve the problems, a new method of complex inserts
packaging fabrication in stereolithography is proposed in this paper. Based on the geometric
information, function and assembly direction of the inserts, the packaging approach is developed.
The approach proposed in this paper has been verified by experiments. It brings considerable
contributions to the application of insert packaging in stereolithography. It is also favorable to
the improvement of insert packaging efficiency and assembly fabrication",,,,,,
"['Tarasova, A.', 'Wegner, A.', 'Witt, G.']",2021-11-18T02:19:44Z,2021-11-18T02:19:44Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90412', 'http://dx.doi.org/10.26153/tsw/17333']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['maximum filler volume packing fraction', 'laser sintering', 'polymers', 'reinforcement', 'fillers', 'additive manufacturing']",Approach to Defining the Maximum Filler Packing Volume Fraction in Laser Sintering on the Example of Aluminum-Filled Polyamide 12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/015c75c0-0de2-45a0-9561-a6e002ccde38/download,University of Texas at Austin,"Laser sintering is one of the most popular additive manufacturing techniques that uses
thermoplastic polymer powders to generate layer-by-layer complex structures. Despite its broad
application, some limitations exist restricting its further development. One such restriction is a
narrow assortment of commercially available materials that would allow the production of the parts
with the desired mechanical characteristics, which is the case with the widely used Polyamide 12
(PA12). Reinforcement of a matrix polymer with metal particles is routinely performed to achieve
better mechanical properties. In this work, a PA12 system enhanced with a 35% volume ratio of
aluminum was investigated. Mechanical characteristics, e.g. elastic and flexural moduli, were
examined with respect to variation of manufacturing process parameters. In addition, a new
methodology was tested, which should help determine the maximum filler packing volume fraction
corresponding to the highest mechanical characteristics of a polymer-filler mixture.",,,,,,
"['Rivette, M.', 'Mognol, P.', 'Hascoet, JY.']",2020-03-05T18:51:28Z,2020-03-05T18:51:28Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80142', 'http://dx.doi.org/10.26153/tsw/7163']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Rapid Prototyping,Approach Tolerance in the Assemblies of Evolutionary Hybrid Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7662fd9c-f37f-475c-b6e6-4a6f6da644ae/download,,"A new answer is proposed to replace the traditional “one shot” prototype (manufactured in
one piece with one process): the hybrid rapid prototype. It is used to highly reduce time,
cost and increase reactivity during the development times of new products.
The part is decomposed in several components which can quickly be changed and can be
manufactured with a process the most adapted.
The main objective of the presented method is to propose an available technological
assembly between the different components of the part in the respect of technological and
topological function, and initial tolerance.
Using a graph of representation, fuzzy logic and a tolerance point of view, some entities are
associated with a CIA (Assembly Identity Card) in accordance with evolutionary and
manufacturing analysis. This work will be illustrated by an industrial tooling for plastic
injection.",,,,,,
"['Dreifus, G.D.', 'Jin, Y.', 'Ally, N.', 'Post, B.K.']",2021-11-01T20:40:58Z,2021-11-01T20:40:58Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89739,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['geometric restrictions', 'big area additive manufacturing', 'fused deposition modeling', 'additive manufacture']",Approaches to Geometric Data Analysis on Big Area Additively Manufactured (BAAM) Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/916f64eb-e52a-45a9-aba3-3216012551c1/download,University of Texas at Austin,"The promise of additive manufacturing is that a user can design and print complex geometries
that are very difficult, if not impossible, to machine. The capabilities of 3D printing are restricted
by a number of factors, including properties of the build material, time constraints, and
geometric design restrictions. In this paper, a thorough accounting and study of the geometric
restrictions that exist in the current iteration of additive manufacturing (AM) fused deposition
modeling (FDM) technologies on a large scale are discussed. Offline and online methodologies
for collecting data sets for qualitative analysis of large scale AM, in particular Oak Ridge
National Laboratory’s (ORNL) big area additive manufacturing (BAAM) system, are
summarized. In doing so, a survey of tools for designers and software developers is provided. In
particular, strategies in which geometric data can be used as training sets for smarter AM
technologies in the future are explained.",,,,,,
"['Lao, Wenxin', 'Li, Mingyang', 'Masia, Lorenzo', 'Tan, Ming Jen']",2021-11-08T22:34:42Z,2021-11-08T22:34:42Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90058', 'http://dx.doi.org/10.26153/tsw/16979']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['rectangular extrudate', 'nozzle design', '3D printing for building and construction', 'extrusion based 3D printing']",Approaching Rectangular Extrudate in 3D Printing for Building and Construction by Experimental Iteration of Nozzle Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/608f8abe-dd66-4683-b77a-ea49ef0abf48/download,University of Texas at Austin,"In Extrusion based 3D Printing technology, the voids could be reduced and the surface finish of printed parts could be improved with extrudate shape optimization. For
large-scale 3D Printing technology like 3D Printing for Building and Construction, reducing printed layer height would increase the fabrication time drastically, while having
few effect on voids reduction and surface finish improvement. In this paper, an iterative
experimental approach to achieve the optimized nozzle design for rectangular shaped extrudate was proposed. Two nozzle prototypes were manufactured by Fused Deposition
Method and implemented for experimental tests, then a new nozzle design was created
based on the experimental extrudate shapes. This process iterated until a good rectangular extrudate shape was obtained. Printing tests were conducted with the optimized
nozzle, which showed the designed nozzle could help to eliminate the voids among the
printed parts and guarantee good surface finish without losing the speed of printing.",,,,,,
"['Mason, Michael S.', 'Huang, Tieshu', 'Landers, Robert G.', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Hayes, Michael W.']",2020-03-09T14:07:39Z,2020-03-09T14:07:39Z,9/4/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80180', 'http://dx.doi.org/10.26153/tsw/7199']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Aqueous-Based Extrusion Fabrication,Aqueous-Based Extrusion Fabrication of Ceramics on Demand,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38bfdf1c-5680-4788-83a8-7442207e2589/download,,"Aqueous-Based Extrusion Fabrication is an additive manufacturing technique that
extrudes ceramic slurries of high solids loading layer by layer for part fabrication. The
material reservoir in a previously developed system has been modified to allow for
starting and stopping of the extrusion process on demand. Design pros and cons are
examined and a comparison between two material reservoir designs is made. Tests are
conducted to determine the optimal deposition parameters for starting and stopping the
extrudate on demand. The collected test data is used for the development of a deposition
strategy that improves material deposition consistency, including reduced material
buildup at sharp corners. Example parts are fabricated using the deposition strategy and
hardware design.",,,,,,
"['Delfs, P.', 'Schmid, H.-J.']",2021-11-08T22:37:43Z,2021-11-08T22:37:43Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90059', 'http://dx.doi.org/10.26153/tsw/16980']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['process parameters', 'laser sintered parts', 'surface roughness', 'laser sintering']",Areal Surface Characterization of Laser Sintered Parts for Various Process Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a57f82c-d39b-4fa7-a6bf-1fa556d56926/download,University of Texas at Austin,"Laser sintered polymer parts consist of rough surfaces due to the layered manufacturing and adherence of
incomplete molten particles. The absolute roughness depend on various process parameters like build angle,
spatial position, build temperature, exposure order and layer time. Analyses with the help of several areal
roughness values of DIN EN ISO 25178-2 considering these parameters are introduced in this paper. Multiple
build jobs with 120 µm layer thickness and PA2200 powder were built on an EOS P396 machine using the same
build job design with varying process parameters. An individual sample part was designed to receive lots of
surface topography information with optical 3D measurements. The results show roughness dependencies for 0°
to 180° build angles in 15° steps and eleven distributed in-plane and three axial direction positions depending on
different build temperatures, reversed exposure order and layer times. Limitations of the varied parameters are
finally derived for the manufacturing of improved surface qualities.",,,,,,
"['Razdan, Anshuman', 'Henderson, Mark R.', 'Collins, Dan']",2019-02-19T20:28:07Z,2019-02-19T20:28:07Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73445', 'http://dx.doi.org/10.26153/tsw/597']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['PRISM', 'Anthropology']",Art to Engineering: Pervasive RP activities at Arizona State University,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dd3623a9-9a28-4363-9cc9-5e91b2b3913f/download,,"We present a sampling ofwidely diverse Rapid Prototyping activities at ASU. Through the interdisciplinary PRISM
project, RP is firmly involved in three areas: education, research and outreach. Two courses have been developed,
one teaches RP over the web and the other Visualization and RP as applied technologies aimed at interdisciplinary
graduates and seniors. Researchers and students from Engineering, Architecture and Industrial Design, Fine Arts
and Liberal Arts and Sciences and Business actively use RP. A recent formation ofthe PARfC (PRISM Advanced
Rapid-fabrication Consortium) Consortium with local industry will create a local and formal center for research,
education, service and training in Rapid Fabrication.",,,,,,
"['Stavroulakis, P.', 'Davies, O.', 'Tzimiropoulos, G.', 'Leach, R.K.']",2021-11-09T14:54:28Z,2021-11-09T14:54:28Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90087', 'http://dx.doi.org/10.26153/tsw/17008']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['artificial intelligence', 'data fusion', 'photogrammetry', 'fringe projection', 'deflectometry', 'segmentation network']",Artificial Intelligence-Enhanced Mutli-Material Form Measurement for Additive Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6efe19f6-3225-4e23-9852-1405e9892be6/download,University of Texas at Austin,"The range of materials used in additive manufacturing (AM) is ever growing nowadays.
This puts pressure on post-process optical non-contact form measurement systems as different
system architectures work most effectively with different types of materials and surface finishes.
In this work, a data-driven artificial intelligence (AI) approach is used to recognise the material of
a measured object and to fuse the measurements taken from three optical form measurement
techniques to improve system performance compared to using each technique individually. More
specifically, we present a form measurement system which uses AI and machine vision to enable
the efficient combination of fringe projection, photogrammetry and deflectometry. The system has
a target maximum permissible error of 50 μm and the prototype demonstrates the ability to measure
complex geometries of AM objects, with a maximum size of (10 × 10 × 10) cm, with minimal user
input.",,,,,,
"Gibson, I.",2021-10-05T15:46:10Z,2021-10-05T15:46:10Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88396', 'http://dx.doi.org/10.26153/tsw/15335']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Rapid Prototyping']",Ask Not What Additive Manufacturing Can Do For You...,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b319e394-28bb-4251-b449-faf06b176d02/download,University of Texas at Austin,"The paraphrase of John F Kennedy’s famous words is for 2 purposes. Firstly it is to
acknowledge that there are some people who have considered that it is a major part of their life’s
work to promote Additive Manufacturing (AM) technology as primarily a selfless act. AM
comprises an outstanding range of technology that should be brought to public attention as a true
revolution in how we design and manufacture products. The second purpose is to show that
technology development is only one part of this promotion process and that there are other ways
in which we can get involved.
This paper describes the author’s journey over the (approximately) 20 years since he was
introduced to what was then called Rapid Prototyping (RP). It is not a catalogue of research and
development projects but rather a list of activities that he has been involved in to help promote
and support AM technology over these years. It will describe the conferences, activities,
associations and publications that have been created to allow academics and professionals to
describe and discuss their work amongst themselves and to the larger society.",,,,,,
"['Deng, Dongping', 'Chen, Yong']",2021-10-07T17:32:07Z,2021-10-07T17:32:07Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88489', 'http://dx.doi.org/10.26153/tsw/15423']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'in-situ assembly', 'thin-shell structure', 'origami design', 'folding', 'fabrication speed']",Assembled Additive Manufacturing – A Hybrid Fabrication Process Inspired by Origami Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/507c9518-c8e8-4060-a218-539ca9cd8c03/download,University of Texas at Austin,"Inspired by the recent developments on origami structures, we investigated a fast AM process for
fabricating prototype models of thin-shell shapes. By combining the origami design and the additive
manufacturing technology, a new fabrication process named Assembled Additive Manufacturing (AAM)
is developed. In the process, a digital model is first analyzed to determine geometries that are fabricated
by the layer-based and origami-based approaches. The thin shell model for the origami-based approach is
then unfolded into a foldable 2D sheet. After the fabrication and folding of the 2D sheet, a postprocessing
process is developed before the final prototype is fabricated using the layer-based fabrication process.
Algorithms of analyzing and unfolding polygonal model and the details of the process are introduced in
the paper; design parameters, mechanics analysis and test cases are also discussed.",,,,,,
"['Telenko, Cassandra', 'Seepersad, Carolyn Conner']",2021-09-30T14:37:38Z,2021-09-30T14:37:38Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88258', 'http://dx.doi.org/10.26153/tsw/15199']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'Rapid Manufacturing', 'life-cycle', 'nylon powder material', 'material properties', 'environmental effects']",Assessing Energy Requirements and Material Flows of Selective Laser Sintering of Nylon Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6bc4c52-736c-42ff-8033-fbbc2aeab1af/download,University of Texas at Austin,"Selective laser sintering (SLS) is a prominent technology for rapid manufacturing (RM) of
functional parts. SLS and competitive RM technologies are generally assumed to be more
environmentally sustainable than conventional manufacturing methods because the additive
process minimizes tooling, material waste, and chemical fluids. A thorough life cycle analysis
(LCA) of the environmental impacts of SLS has yet to be published. This study focuses on a
section of the SLS part life-cycle. It tracks the nylon powder material flows from the extraction
and synthesis of the material to SLS part production. Basic material properties and
environmental effects are reported. Estimates of material waste and energy use are also reported
and compared with those of injection molding.",,,,,,
"['Cloots, M.', 'Spierings, A.B.', 'Wegener, K.']",2021-10-11T21:45:39Z,2021-10-11T21:45:39Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88654', 'http://dx.doi.org/10.26153/tsw/15588']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'SLM', 'metal parts', 'support structures', 'overhanging surfaces', 'support minimization', 'process heat', 'geometrical distortions', 'additive manufacturing']",Assessing New Support Minimizing Strategies for the Additive Manufacturing Technology SLM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67b73d0a-7b05-4b89-87c7-cc7d2f9f6e15/download,University of Texas at Austin,"To successfully produce metal parts by SLM, additional support structures are needed to
support overhanging surfaces in order to dissipate process heat and to minimize geometrical
distortions induced by internal stresses. These structures are often massive and require additional
post-processing time for their removal. A minimization of the extent to which support structures
are needed would therefore significantly reduce manufacturing and finishing efforts and costs. A
specific component segmentation strategy is developed. It allows the segmentation of critical
areas of the component by applying a specific scanning strategy with appropriate energy input
and optimized supporting strategies. The results indicate that the supporting effort can generally
be reduced, e.g. overhang geometries with an angle to the horizontal of less than 35° can be
manufactured without any support. The successful realization of the segmentation strategy in
combination with optimized support structures allows the implementation of a stacking strategy,
thereby using the available work space more efficiently.",,,,,,
"['Poudel, Arun', 'Yasin, Mohammad Salman', 'Shao, Shuai', 'Shamsaei, Nima']",2023-02-10T14:23:05Z,2023-02-10T14:23:05Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117453', 'http://dx.doi.org/10.26153/tsw/44334']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser powder bed fusion (L-PBF)', 'Non-destructive testing', 'X-ray computed tomography', 'Process window', 'Rockwell hardness']",Assessing the Feasibility of Process Window Estimation for L-PBF Ti-6Al-4V through Hardness Measurements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7764f1b3-b6c3-4f12-a73d-85e1049cde9a/download,,"Optimizing the process window for an additively manufactured material using X-ray 
computed tomography (XCT) is a time-, labor-, and capital-intensive process where a large number 
of coupons need to be analyzed in the process parameter space. Hence, as a cheaper and faster 
alternative, this study assessed the relationship between relative density and hardness of laser 
powder bed fused (L-PBF) Ti-6Al-4V. Coupons with different levels of porosity were fabricated 
by changing the recommended laser power in the range of ±20% in an interval of 10%. The 
martensitic microstructure didn’t vary significantly with the change in laser power. On the other 
hand, Rockwell C hardness (HRC) did. HRC was observed to be in good correlation with the defect 
content in the coupons. Higher defect content in the coupons resulted in lower HRC and vice versa. 
Hence, the hardness measurement technique can be used to estimate the process window of L-PBF 
Ti-6Al-4V.",,,,,,
"['Kletetzka, I.', 'Neitzel, F.', 'Schmid, H.-J.']",2024-03-25T22:31:21Z,2024-03-25T22:31:21Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124323', 'https://doi.org/10.26153/tsw/50931']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'powder', 'ceramic', 'additive manufacturing']",Assessing the Impact of the Powder Production Method on Ceramic-filled Polyamide Composites made by Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b2f310c-35c4-4afe-bcb7-8fa7f5e63515/download,University of Texas at Austin,"Polymer composites represent the industry standard in injection molding for the production
of plastic components with increased requirements in terms of heat resistance and stiffness. In the
field of laser sintering (LS), these materials are less common so far. In order to extend the available
material variety for the LS process, new ceramic-filled Polyamide 613 powders are investigated
within the scope of this work. Here, the resulting properties from two different powder production
methods are compared. One filled powder is produced by dry blending and the other powder with
the same filler and filling ratio is produced by encapsulating the filler particles inside the polymer
particles within the dissolution-precipitation process. It was found that encapsulating the filler
particles can provide certain benefits for the processability, for example an improved powder
flowability or better filler dispersion. However, encapsulating the filler also alters the thermal
properties of the precipitated powder.",,,,,,
"['Hauser, C.', 'Childs, T.H.C.', 'Dalgarno, K.W.', 'Eane, R.B.']",2019-03-12T17:54:01Z,2019-03-12T17:54:01Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73605', 'http://dx.doi.org/10.26153/tsw/747']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Metallography', 'Atmosphere']",Atmospheric Control during Direct Selective Laser Sintering of Stainless Steel 314S Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dabd68c4-c148-4594-8e64-fb48c74d4917/download,,"Stainless steel grade 314S powders have been Selective Laser Sintered (SLS) in three
different argon/air (oxygen) atmospheric mixtures. The amount of oxygen present during the
heating, melting and fusing of the metal powder strongly limits the range of laser powers and
scanning speeds for successful processing. As oxygen levels diminish, powder oxidation
reduces. This reduces absorption of laser energy as well as balling and other detrimental
surface phenomena. This paper reports the conditions for creating sintered layers and
observations of part quality variation within these conditions. Sintered microstructure
observations are also helpful in determining thermal history changes.",,,,,,
Koch,2018-05-03T18:25:19Z,2018-05-03T18:25:19Z,1993,Mechanical Engineering,doi:10.15781/T2ZC7SB82,http://hdl.handle.net/2152/65053,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['DIGIBOT 3D', 'laser digitizer', '3D systems', 'CAD', 'CAM', 'CAE']",Automated 4 Axis Adaptive Scanning with the Digibotics Laser Digitizer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ecadda3e-47bd-4e2a-b7f4-7160840e6fb6/download,,"The DIGIBOT 3D Laser Digitizer is a high performance 3D input device which
combines laser ranging technology, personal computing, and Microsoft Windows in an
attractive desktop package.
With its full four-axis scanning capabilities, the DIGIBOT provides a simple,
accurate, and quick way to copy or inspect complex, sculpted surfaces. The DIGIBOT
provides an effective solution for many industrial and academic problems involving 3D
design, inspection, replication, analysis, and visualization/animation. By measuring
sequential points and producing a standard list of x/y/z coordinates, the DIGIBOT
interfaces to any CAD/CAM/CAE imaging or animation software that reads 3D points,
contours, or triangular facets.",,,,,,
"['Zhao, Xiyue', 'Imandoust, Aidin', 'Khanzadeh, Mojtaba', 'Imani, Farhad', 'Bian, Linkan']",2021-12-01T22:39:34Z,2021-12-01T22:39:34Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90642', 'http://dx.doi.org/10.26153/tsw/17561']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['anomaly detection', 'melt pool monitoring', 'sparse representation', 'unsupervised learning', 'direct energy deposition', 'additive manufacturing']",Automated Anomaly Detection of Laser-Based Additive Manufacturing Using Melt Pool Sparse Representation and Unsupervised Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa2422df-92ff-4ec2-83e7-65a0e2b11b56/download,University of Texas at Austin,"Advanced thermal imaging is increasingly invested in direct energy deposition (DED) additive
manufacturing (AM) to cope with information visibility of melt pool and tackle process
inconsistency. However, there are key challenges regarding the feasibility of current image-guided
monitoring methodologies in the DED process. First, high-resolution thermal images consist of
millions of pixels captured by hundreds of frames lead to the curse of dimensionality in analysis.
Second, the presence of various exogenous noise, ill-structured data, and significant cluster
imbalance limit the capability of the current methodologies to perform real-time monitoring. The
objective of this research is to advance the frontier of melt pool monitoring in DED process by
designing an automated and unsupervised anomaly detection on high-dimensional thermal image
data. Specifically, we develop a variational autoencoder to generate a low-dimensional
representation of each input thermal image data. A Gaussian mixture model and K-Mean clustering
are integrated with the generative model to split latent space into homogenous regions and detect
anomalies. Experimental results show that the proposed methodology is highly effective in
detecting defective melt pools with accuracy up to 94.52% and a false alarm rate of less than 2.1%.",,,,,,
"['Khoshnevis, B.', 'Kwon, H.', 'Bukkapatnam, S.']",2019-10-18T16:37:59Z,2019-10-18T16:37:59Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76255', 'http://dx.doi.org/10.26153/tsw/3344']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Contour,Automated Construction using Contour Crafting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e21a2cda-7539-4e0c-884d-f0c2a14ea52e/download,,"This paper presents some concepts and initial investigation of a novel construction
automation approach using the Contour Crafting (CC) layered fabrication process, developed at
the University of Southern California. CC uses computer control to take advantage of the
superior surface forming capability of trowels, used by craftsmen and builders since ancient
times, to create large intricate structures with smooth and accurate surfaces. The potential of CC
became evident from the initial investigations and experiments with various materials and
geometries. Using this process, a single house or a colony of houses, each with possibly a
different design, may be automatically constructed in a single setup.",,,,,,
"['Ramin, E.', 'Harris, R. A.']",2020-03-10T14:49:22Z,2020-03-10T14:49:22Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80211', 'http://dx.doi.org/10.26153/tsw/7230']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Tissue Engineering scaffolds,Automated Design of Tissue Engineering Scaffolds by Advanced CAD,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fdae97c-8581-4cf8-a8b4-adb524e91907/download,,"The design of scaffolds with an intricate and controlled internal structure represents a
challenge for Tissue Engineering. Several scaffold manufacturing techniques allow the
creation of complex and random architectures, but have little or no control over geometrical
parameters such as pore size, shape and interconnectivity- things that are essential for tissue
regeneration. The combined use of CAD software and layer manufacturing techniques allow
a high degree of control over those parameters, resulting in reproducible geometrical
architectures. However, the design of the complex and intricate network of channels that are
required in conventional CAD, is extremely time consuming: manually setting thousands of
different geometrical parameters may require several days in which to design the individual
scaffold structures. This research proposes an automated design methodology in order to
overcome those limitations. The combined use of Object Oriented Programming and
advanced CAD software, allows the rapid generation of thousands of different geometrical
elements. Each has a different set of parameters that can be changed by the software, either
randomly or according to a given mathematical formula, so that they match the different
distribution of geometrical elements such as pore size and pore interconnectivity.
This work describes a methodology that has been used to design five cubic scaffolds with
pore size ranging from about 200 to 800 µm, each with an increased complexity of the
internal geometry.",,,,,,
"['Cooper, A.G.', 'Kang, S.', 'Kietzman, J.W.', 'Prinz, F.B.', 'Lombardi, J.L.', 'Weiss, L.']",2019-03-01T17:39:48Z,2019-03-01T17:39:48Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73519', 'http://dx.doi.org/10.26153/tsw/669']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Mold Shape Deposition', 'Ceramic materials']",Automated Fabrication of Complex Molded Parts Using Mold SOM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b6223daa-1c38-47d3-a09f-ef0fc87d8ff9/download,,"Mold Shape Deposition Manufacturing (Mold SDM) is a Solid Freeform Fabrication
technique for producing complex shaped fugitive wax molds. A vari~ty of castable. polymer and
ceramic materials have been used to make parts from these molds. ThIS paper descnbes the Mold
SDM method and an automated mold building machine based on a commercial CNC mill. Process
steps, material selection and equipment issues are explained. Alumina, silicon nitride, polyurethane
and epoxy parts with feature sizes ranging from 0.5 to 30 mm will be shown, as well as preassembled mechanisms and multi-material parts.",,,,,,
"['Klosterman, Don', 'Chartoff, Richard', 'Osborne, Nora', 'Graves, George']",2018-12-06T21:30:53Z,2018-12-06T21:30:53Z,1997,Mechanical Engineering,doi:10.15781/T2SX64W60,http://hdl.handle.net/2152/71432,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'CMC']",Automated Fabrication of Monolithic and Ceramic Matrix Composites via Laminated Object Manufacturing (LaM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d02a74e-fe28-45b7-a8a2-ff86af5265ed/download,,"This report summarizes recent developments in a research program for fabricating
advanced monolithic and ceramic matrix composite parts using Laminated Object
Manufacturing (LOM). Both silicon carbide (SiC) and SiC/SiC composites are
discussed. The LOM process is used to produce green forms that are then densified using
various post processing operations. The monolithic ceramic LOM process was advanced
through the implementation of an automated solvent spray bonding step, significant
improvement in decubing with new software, and an intensive round ofmechanical
characterization. The LOM process for making CMC green forms is fully developed.
This entailed implementing a process for making suitable SiC fiber preforms, a laser
cutting capability, a decubing strategy, and a binder resin cure procedure. Further
research is ongoing for the post processing pyrolysis and reaction bonding steps as
discussed herein.",,,,,,
"['Steidle, Cheri', 'Klosterman, Don', 'Osborne, Nora', 'Graves, George', 'Chartoff, Richard']",2019-02-27T17:45:00Z,2019-02-27T17:45:00Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73508', 'http://dx.doi.org/10.26153/tsw/658']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Chemical Engineering', 'LOM']",Automated Fabrication of Nonresorbable Bone Implants Using Laminated Object Manufacturing (LOM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/a85b69a2-e075-429e-bf3e-1865b83501cc/download,,,,,,,,
"['Mathewson, Brian B.', 'Newman, Wyatt S.', 'Heuer, Arthur H.', 'Cawley, James D.']",2018-11-02T14:59:11Z,2018-11-02T14:59:11Z,1995,Mechanical Engineering,doi:10.15781/T2959CT1S,http://hdl.handle.net/2152/69332,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'custom manufacturing', '3D Laminated Engineering Components']",Automated Fabrication ofCeramic Components from Tape-Cast Ceramic,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5be81cf5-85df-485e-bdb4-27b78ddc6aa9/download,,"This paper describes a machine and process for automated fabrication of functional 3-D
laminated engineering components, ceramics in the present example. A laser cuts successive layers
of a part derived from a CAD model description out of unfired tape-cast ceramic sheets
vacuum-clamped to an x-y sled. A material-handling robot uses a selective-area gripper to extract
only the desired part outlines from the surrounding waste material, then stacks the slices to build the
part. This system design enables rapid manufacture of functional engineering components with
arbitrarily complex internal and external geometries from virtually any material available in sheet
form.",,,,,,
"['Dakshnamoorthy, Vignesh', 'Taylor, Robert V.']",2021-11-01T21:19:33Z,2021-11-01T21:19:33Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89757,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['lattice structure', 'optimization', 'hinge fitting', 'goose neck door hinge', 'part design', 'stiffness', 'additive manufacturing']",Automated Lattice Optimization of Hinge Fitting with Displacement Constraint,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47d45fcc-d6dc-466c-a26b-98de52fb3e0c/download,University of Texas at Austin,"Additive manufacturing enables fabrication of complex lattice cell structures that are not
manufacturable using conventional methods. In order to exploit this lattice capability in
structural designs, the effect on structural performance must be considered. This paper uses a
goose neck door hinge component to illustrate the effects of lattice structure optimization when
stiffness criteria drive part design. The effect of intermediate lattice cell density parameters on
resulting lattice configurations from automated lattice structure optimization are studied and it is
found that the compliance of the model depends upon the range of intermediate density elements
present. The paper then compares the effect of a displacement constraint on optimized weight
from rib-stiffened and lattice-stiffened shell models. It is shown that optimized weight results
from the lattice configuration depend on part stiffness requirements. The results show that lattice
structures can be successfully implemented in weight-critical components where relaxation in the
displacement constraint is acceptable.",,,,,,
"['Chang, Y. C.', 'Pinilla, J. M.', 'Kao, J.H.', 'Dong, J.', 'Ramaswami, K.', 'Prinz, F.B.']",2019-03-11T16:45:53Z,2019-03-11T16:45:53Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73582', 'http://dx.doi.org/10.26153/tsw/724']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD']",Automated Layer Decomposition for Additive/Subtractive Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/35b09cd4-ffc4-4e0c-94b4-0c6cbc82d722/download,,"The new additive/subtractiye technology (Shape. Deposition Manufacturing) enhances Solid Freeform
Fabrication (SFF) capability inproducing near net-shape surface finish. This. technology also builds parts in fewer
layers compared with conventional layered manufacturing technology. However, to decompose a part into freeform
layers usually requires expensive geometric computation.. Also, to plan build. sequences often requires human
intervention because ofthe complicated spatial relationships among the freeform layers. At present decomposition and
build sequence planning are both performed by experienced designers/users. In this paper, a novel decomposition
approach based on surface splitting is proposed to facilitate .computation and planning of the additive/subtractive SFF
processes. The results shown in this paper are from models with 3D planar geometry. Continuous effort is devoted
into extending and implementing this new approach for models with 3Dfreeform.geometry",,,,,,
"['Wadidie, A.', 'Studer, G. M.', 'Villez, K.']",2024-03-27T03:18:46Z,2024-03-27T03:18:46Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124461', 'https://doi.org/10.26153/tsw/51069']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['large area additive manufacturing', '3D printing', 'thresholding', 'edge detection']",Automated layer identification in large area additive manufacturing (LAAM): A comparison of image thresholding and edge detection techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5981225d-ea2c-444f-9d76-bcc44c622817/download,University of Texas at Austin,"Our study aims to develop an automated method for identifying layers on images of 3Dprinted walls from a LAAM printer, as manual identification is subjective and can be timeconsuming. We applied three different image processing methods to identify edges between layers:
simple thresholding, Otsu thresholding, and Canny edge detection. Otsu thresholding was found
to be the most accurate and required minimal manual intervention. From our study, we propose a
new approach by going through essential steps for greater accuracy. This research demonstrates
the feasibility of using computer-based methods to automatically identify layers in 3D printing,
reducing manual time and effort and improving the strength and quality of 3D-printed parts.",,,,,,
"['Rasoolian, Behnam', 'Pegues, Jonathan', 'Shamsaei, Nima', 'Silva, Daniel']",2021-11-30T20:22:53Z,2021-11-30T20:22:53Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90535', 'http://dx.doi.org/10.26153/tsw/17454']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fatigue behavior', 'roughness', 'radius of curvature']",An Automated Method for Geometrical Surface Characterization for Fatigue Analysis of Additive Manufactured Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c63b0cb0-a249-48fa-bcb7-ed65d7280e50/download,University of Texas at Austin,"Recent interest to implement additive manufactured parts into structural applications has created
a critical need to better understand the fatigue behavior of these parts. Alloys such as Ti-6Al-4V
are popular in the aerospace and biomedical industries due to their superior strength to weight ratio
and biocompatibility. Previous works have associated fatigue behavior with surface roughness,
especially radius of curvature of notches. It is therefore important to develop a fast, reliable and
consistent methodology for extracting such curvatures. The contribution of this paper is in
providing an automated method for extracting radius of curvature using image processing
techniques and optimization. Results on fatigue life prediction indicates similar results between
the automated method and manually extracted radii in a significantly shorter period of time.",,,,,,
"['Borish, Michael', 'Roschli, Alex']",2023-01-26T14:51:21Z,2023-01-26T14:51:21Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117311', 'http://dx.doi.org/10.26153/tsw/44192']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['slicing', 'Additive manufacturing', 'wire coextrusion', 'wire embedding', 'self-heating molds', 'composite']",Automated Path Planning for Wire Feeding in Large Format Polymer Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eabf70cf-d5ed-40a4-9720-215ee4a304ba/download,,"Polymer-based large format industrial additive manufacturing (AM) technology continues to expand 
into new application areas. One area of interest is large scale composite molds and dies. These molds and dies 
can be used for out-of-autoclave tooling applications. However, at these sizes, several challenges remain that 
prevent the use of AM technology due to cost. One such challenge is the need to heat these molds in large 
thermal ovens. To address this challenge, researchers at Oak Ridge National Laboratory developed the 
necessary hardware to allow co-extruded wire to be embedded into the material during construction. Using this 
hardware, a demonstration mold was successfully constructed and subjected to mechanical testing. The 
construction of this object required a unique pathing solution to achieve success. In this paper, we describe the 
needed software development in ORNL Slicer 2.0 to allow the automated production of this unique pathing 
solution.",,,,,,
"['Dong, Jianpeng', 'Kao, Ju-Hsien', 'Pinilla, Jose M.', 'Chang, Yu-Chi', 'Prinz, Fritz B.']",2019-03-11T16:47:56Z,2019-03-11T16:47:56Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73583', 'http://dx.doi.org/10.26153/tsw/725']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'CAM']",Automated Planning for Material Shaping Operations in Additive/Subtractive Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f19fb637-eb29-4c87-8867-017897ac6dd2/download,,"Combining the advantages of layered manufacturing and material removal
processes, additive/subtractive solid freeform fabrication (A/S SFF) can build parts with
complex shapes without compromising precision requirements. However, preparing
material removal operations requires special expertise, which has in fact become one of the
bottlenecks of the A/S SFF manufacturing process. To achieve automated planning, a
shaping process planner is being developed based on. 3D solid representation and a surface
classification scheme. This planner can generate numeric control (NC) codes for CNC
milling in an automatic fashion on non-undercut features of arbitrary 3D input geometry.
Planning approaches are also presentedinorde~to>shape parts accurately and efficiently.
The proposed shaping planner thus delivers on the promise offully automated process
planning in A/S SFF.",,,,,,
"['Bohn, John Helge', 'Wozny, Michael J.']",2018-04-19T16:20:26Z,2018-04-19T16:20:26Z,1992,Mechanical Engineering,doi:10.15781/T2QJ78F8R,http://hdl.handle.net/2152/64380,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['CAD-models', 'de facto', 'CAD-models']",Automatic CAD-model Repair: Shell-Closure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8f26990e-8520-43f0-a295-e23658000bfe/download,,"Shell-closure is critical to the repair of CAD-models described in the .STL file-format,
the de facto solid freeform fabrication industry-standard. Polyhedral CAD-models that
do not exhibit shell-closure, i.e. have cracks, holes, or gaps, do not constitute valid solids
and frequently cause problems during fabrication. This paper describes a solution for
achieving shell-closure of polyhedral CAD-models. The solution accommodates nonmanifold
conditions, and guarantees orientable shells. There are several topologically
ambiguous situations that might arise during the shell-closure process, and the solution
applies intuitively pleasing heuristics in these cases.",,,,,,
"['Mireles, Jorge', 'Terrazas, Cesar', 'Medina, Francisco', 'Wicker, Ryan']",2021-10-11T22:09:27Z,2021-10-11T22:09:27Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88663', 'http://dx.doi.org/10.26153/tsw/15597']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Arcam A2 Electron Beam Melting', 'Electron Beam Melting', 'automatic feedback control', 'temperature stabilization', 'infrared camera']",Automatic Feedback Control in Electron Beam Melting Using Infrared Thermography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ccafcc0-24f5-4390-ad23-ceb4d77f518c/download,University of Texas at Austin,"An infrared (IR) camera has been installed in an Arcam A2 Electron Beam
Melting (EBM) system for improved layer-by-layer monitoring and feedback control of
the EBM build process. Previous work has demonstrated the temperature variations
possible during a build (e.g., part/powder bed temperature elevates as build height
increases) that have been shown to produce microstructural changes as well as a range of
defects that can be detected (e.g., temperature anomalies and porosity). A stabilization of
temperature during a build can lead to more uniform microstructure and mechanical
properties throughout the fabricated part. Further, full spatial and temporal control of
temperature could lead to controlled microstructural architectures in EBM-fabricated
parts. An automatic feedback control system was developed to acquire a temperature
matrix of the current layer and used as an input to a ‘ghost operator’ that modifies the
necessary parameters (speed function, beam current, melt cycle’s post-heating time) for
temperature stabilization to minimize microstructural variations.",,,,,,
"['Cook, D.', 'Knier, B.', 'Gervasi, V.', 'Stahl, D.']",2021-09-30T19:56:45Z,2021-09-30T19:56:45Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88289', 'http://dx.doi.org/10.26153/tsw/15230']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['solid-freeform-fabrication', 'finite-element analysis', 'minimal-mass lattice structures', 'structural performance', 'process parameters', 'multi-functional structures', 'high-performance-computing']","Automatic Generation of Strong, Light, Multi-Functional Structures from FEA Output",Conference paper,https://repositories.lib.utexas.edu//bitstreams/4563c28d-e4c0-44d1-8b63-2295b6c46382/download,University of Texas at Austin,"An automated process is being developed that will generate a minimal-mass lattice structure that
is fabrication-ready for a selected solid-freeform-fabrication (SFF) process. The results of a
standard, structural, finite-element analysis (FEA) are processed to define the selection,
alignment and sizing of unit lattice elements, such that a minimal-mass structure can be defined.
This process will allow for considerations of structural performance (e.g. safety factor), multiple
loads, as well as process parameters (e.g. materials and min./max. sizes). Further development
would lead to the definitions of composites and multi-functionality, as well as high-performance-computing (HPC) capabilities.",,,,,,
"['Ridwan, S.', 'Mireles, J.', 'Gaytan, S.M.', 'Espalin, D.', 'Wicker, R.B.']",2021-10-12T22:31:50Z,2021-10-12T22:31:50Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88756', 'http://dx.doi.org/10.26153/tsw/15690']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['layerwise monitoring', 'spatial monitoring', 'infrared camera', 'electron beam melting', 'infrared thermography', 'thermal data', 'geometric data']",Automatic Layerwise Acquisition of Thermal and Geometric Data of the Electron Beam Melting Process using Infrared Thermography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/133f5c95-d166-4694-8727-fd1232af5af1/download,University of Texas at Austin,"Layerwise monitoring has become an area of interest in the field of additive
manufacturing because of potential to further enable part qualification during every stage of
fabrication. Spatial monitoring and qualification during part fabrication has never before been
possible with traditional manufacturing processes such as milling or casting. An IR camera has
been externally annexed atop an EBM system to obtain layerwise thermographs throughout the
fabrication process. This paper demonstrates a process to compare each layer of fabrication using
automatically acquired thermal images to the corresponding CAD file for each fabricated object.
Two different methods of image analysis for part detection were compared (analysis on the basis
of color and analysis by edge detection). Detection allowed the quantification of processing
information (average temperature and surface anomalies) and geometric information (surface
area and perimeter). A percent error of the compared surface area was found to range from 5%-
17%, and automatically acquired temperature measurements were within 7.8K of the recorded
thermograph. The methods presented in this research showcase the beginning steps of integrated
metrology in advanced manufacturing systems and automatic monitoring of per-part thermal
behavior and part quality.",,,,,,
"['Thomas, Charles L.', 'Hayworth, Kenneth J.']",2018-11-14T17:23:11Z,2018-11-14T17:23:11Z,1996,Mechanical Engineering,doi:10.15781/T2C82508X,http://hdl.handle.net/2152/70245,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['3D object', 'thermoplastic droplet deposition process', '3D aliasing']",Automating Sheet-Based Fabrication: The Conveyed-Adherent Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/94788f8e-f1ae-4892-9e06-add8ab41e84e/download,,"A new automated fabrication technology is described which breaks the fabrication process into spatially separate
layer-formation and layer-bonding stages. The technique uses sheet material on a substrate as feedstock and cuts
cross-section contours into the material before conveying the material on the substrate to a stacking station.
Advantages include (a) speed, (b) versatility in fabrication materials, and (c) ability to fabricate hollows, embed or
cast secondary materials, and selectively enhance or degrade material properties on a regional basis.
A prototype fabricator has been built which automates all aspects ofthis process except weeding. Applications
demonstrated using this machine include traditional rapid prototyping and visualization-model creation as well as
functional machines taking advantage of embedding and cast-in-place techniques.",,,,,,
"['Stroble, J. K.', 'Landers, R. G.', 'Liou, F. W.']",2020-03-05T18:55:53Z,2020-03-05T18:55:53Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80143', 'http://dx.doi.org/10.26153/tsw/7164']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Aided Manufacturing Process,Automation of a Hybrid Manufacturing System Through Tight Integration of Software and Sensor Feedback,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ab004900-e7bf-4a6b-81f7-cab9563988d9/download,,"This paper presents a framework for the automation of the Laser Aided Manufacturing Process
(LAMP) lab at the University of Missouri-Rolla. The groundwork for the proposed system
involves the integration of the LabVIEW software package and a PXI-8195 real time controller
with several sensors and actuators. The incorporation of all key control parameters into one
virtual instrument will help achieve the goal of an automated hybrid system. To achieve this
goal, a five-phase plan, which will be further discussed in the paper, has been developed. The
first phase of this plan, which includes the deposition of a thin walled structure without DNC
communication between LabVIEW and the CNC has been achieved, and will be the focus of this
paper",,,,,,
"['Ye, Jiafeng', 'Yasin, Mohammad Salman', 'Muhammad, Muztahid', 'Liu, Jia', 'Vinel, Aleksandr', 'Slvia, Daniel', 'Shamsaei, Nima', 'Shao, Shuai']",2021-12-01T22:18:09Z,2021-12-01T22:18:09Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90636', 'http://dx.doi.org/10.26153/tsw/17555']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['nitinol', 'laser beam-powder bed fusion', 'process parameters', 'Bayesian optimization']",Bayesian Process Optimization for Additively Manufactured Nitinol,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dba1a8f6-d315-4aa0-88c3-40882cba161e/download,University of Texas at Austin,"Additively manufactured nitinol enables the design and rapid prototyping of the shape
memory alloy with great flexibility and cost-effectiveness in various applications. To achieve high-density fabrication of nitinol, we utilize a Gaussian process-based Bayesian optimization method
to efficiently optimize process parameters of the laser beam-powder bed fusion (LB-PBF) process
in this work. Specifically, Gaussian process regression is applied to formulate a surrogate model
between the critical process parameters (i.e., laser power, scanning speed) and the residual porosity
of the nitinol samples. Then Bayesian optimization is integrated to successively explore the design
space to search for the optimal process parameters. These two methods are integrated to find the
global optimum iteratively. Compared with the traditional trial-and-error methods, the proposed
method can quickly find the optimal process parameter for the high-quality nitinol samples,
especially with many process parameters, and accelerate the innovations with nitinol in additive
manufacturing.",,,,,,
"['Maskery, I.', 'Aremu, A.O.', 'Simonelli, M.', 'Tuck, C.', 'Wildman, R.D.', 'Ashcroft, I.A.', 'Hague, R.J.M.']",2021-10-13T20:45:58Z,2021-10-13T20:45:58Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88782', 'http://dx.doi.org/10.26153/tsw/15716']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'lattice', 'aluminum alloy']",The BCC Unit Cell for Latticed SLM Parts; Mechanical Properties as a Function of Cell Size,Conference paper,https://repositories.lib.utexas.edu//bitstreams/750511b9-39f2-48b7-b80c-5f45fe862d18/download,University of Texas at Austin,"The existing framework describing the mechanical properties of lattices places strong
emphasis on one important property, the relative density of the repeating cells. In
this work, we explore the effects of cell size, attempting to construct more complete
models for the performance of lattices. This was achieved by examining the elastic
modulus and ultimate tensile strength of latticed parts with a range of unit cell sizes
and fixed density. The parts were produced by selective laser melting (SLM). The
examined cell type was body-centred-cubic (BCC), a cell of high relevance for SLM
because of its self-supporting structure. We obtained power law relationships for the
mechanical properties of our latticed specimens as a function of cell size, which are
similar in form to the existing laws for the density dependence. These can be used
to predict the properties of latticed column structures comprised of BCC cells, and
may be easily amended for other situations. In addition, we propose a novel way to
analyse the elastic modulus data, which may lead to more general models, applicable
to parts of varying size. Lastly, our general methodology may be of use in future
studies which explore the other parameters that determine lattice performance; the
choice of cell type, the global shape of the lattice structure and the type of stress.",,,,,,
"['Ramirez-Chavez, Irving E.', 'Lee, Christine', 'Bhate, Dhruv']",2023-02-24T14:45:29Z,2023-02-24T14:45:29Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117524', 'http://dx.doi.org/10.26153/tsw/44404']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'beam deletion', 'cellular materials', 'densification strain', 'maximum transmitted stress', 'perturbation', 'energy absorption']",Beam Deletion in Square Honeycombs for Improved Energy Absorption Under Quasi-Static In-Plane Compression,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6d4caf4-d501-4750-839f-541dd5f30763/download,,"When selecting cellular materials for energy absorption applications, there have 
traditionally been two choices: a periodic structure such as a honeycomb, or a stochastic one, as 
seen in foams. Both choices involve a global definition governing the allocation of the members 
of the structure, be they beams or surfaces. With Additive Manufacturing, the exploration of more 
complex structures enables the creation of aperiodicity through the local modification of periodic 
structures. This paper explores one application of this approach by deleting beams in square 
honeycombs, with the aim of avoiding localization of failure that generates significant undulations 
in the stress plateau under in-plane quasi-static compression. These perturbed structures show 
improved energy absorption behavior by generating higher Specific Energy Absorption for a given 
transmitted stress and relative density than their periodic counterparts. This work thus argues for 
further exploration of localized aperiodicity as an approach to finely tune energy absorption 
performance.",,,,,,
"['Li, Yongqiang', 'Chen, Yong']",2021-09-30T20:00:56Z,2021-09-30T20:00:56Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88290', 'http://dx.doi.org/10.26153/tsw/15231']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'principal stress line', 'beam structures', 'minimum compliance']",Beam Structure Optimization for Additive Manufacturing based on Principal Stress Lines,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d06615f-9061-4db0-add4-682c5ae4adbb/download,University of Texas at Austin,"The benefits of component design with cellular structures have been demonstrated in a wide
variety of applications. The recent advances in additive manufacturing and high performance computing
have enabled us to design a product component with adaptive cellular structures to achieve significantly
better performance. However, designing a product component with such structures, especially its shape
and topology, poses significant challenges. Many approaches in topology optimization have been
developed before for the purpose. In this paper, we present a novel structural optimization method based
on the principal stress line analysis of a continuum domain. We first present the theoretical basis of our
optimization method. We then discuss the properties of principal stress lines and their computation in a
given design domain. Accordingly a novel structural optimization method is presented including size,
shape and topology optimization. Related mathematical formulations and algorithms are also given for
generating a beam structure with the minimum compliance. Three test cases are presented to illustrate
the presented method.",,,,,,
"['Johnson, W.M.', 'Rowell, M.', 'Deason, B.', 'Eubanks, M.']",2021-10-04T21:18:43Z,2021-10-04T21:18:43Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88349', 'http://dx.doi.org/10.26153/tsw/15288']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacaturing', 'benchmarking models', 'open source AM system', 'fused deposition modeling']",Benchmarking Evaluation of an Open Source Fused Deposition Modeling Additive Manufacturing System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/860a3433-80c5-49c1-9fe4-77299d93babf/download,University of Texas at Austin,"The availability of more affordable open source Additive Manufacturing (AM) systems has lead
to the increased awareness and use of AM technologies. However, further expansion will
necessitate improved reliability and an increased understanding in the limitations of these
systems. This paper will review previous benchmarking models, and present the development of
a new benchmarking model and its application in the evaluation of an open source AM system
based on fused deposition modeling (FDM). The proposed benchmarking model includes
various geometric features to evaluate the AM system in terms of dimensional accuracy, thermal
warpage, staircase effect, and geometric and dimensional tolerances.",,,,,,
"['Yasa, E.', 'Demir, F.', 'Akbulut, G.', 'Cızıoğlu, N.', 'Pilatin, S.']",2021-10-12T22:42:40Z,2021-10-12T22:42:40Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88760', 'http://dx.doi.org/10.26153/tsw/15694']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['powder-bed metal fusion', 'additive manufacturing', 'Inconel 625', 'AM machine']",Benchmarking of Different Powder-Bed Metal Fusion Processes for Machine Selection in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d85c45bf-72dc-4bb1-93c4-49556fca37c3/download,,"In the last decade, additive manufacturing has gained significant interest for direct part
production and started to change the way companies manufacture products; even in very
demanding sectors like aerospace. The biggest challenge for a wider industrial acceptance still
stands as the need for more reliable, repeatable and precise machines for additive manufacturing.
This paper presents a comprehensive benchmarking study for the selection of an additive
manufacturing machine for powder-bed metal fusion process, i.e. Selective Laser Melting or
Direct Metal Laser Sintering or Laser Cusing. Four different machine vendors for the same
technology to be employed for aeroengine part manufacturing using Inconel 625 powder have
been involved for comparing different machine specifications. Many aspects such as dimensional
accuracy, surface quality, need of support structures, density, hardness and process limits
(minimum wall thickness, overhang surfaces, inclinations and curvatures, etc.) are addressed in
the paper. The state-of-the-art in machines for powder-bed metal fusion process is presented
aiming at understanding the current limitations of the technology available today.",,,,,,
"['Jayaram, Dureen', 'Bagchi, Amit', 'Jara-Almonte, C.C.', 'Oreilly, Sean']",2018-09-27T19:48:41Z,2018-09-27T19:48:41Z,1994,Mechanical Engineering,doi:10.15781/T2BG2HV81,http://hdl.handle.net/2152/68608,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'SLS', 'LOM']",Benchmarking of Rapid Prototyping Systems - Beginning to Set Standards,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c427b662-4f55-4313-8d08-9289cf87eee6/download,,"Many rapid prototyping (RP) technologies are available today and more are being developed
around the world. The absence of benchmarking standards in the RP industry has led
manufacturers to use their own standards and make claims about superior performance. The need
for testing standards is already felt; standardization will become imperative in the near future. The
present work aims to lay the groundwork for the development of standards to measure various
performance factors. Issues such as appearance and finish are studied qualitatively; the test part
and some findings are presented. Issues such as repeatability, warpage, curl, creep, shrinkage and
tensile strength are proposed to be studied quantitatively; test parts designed for studying these are
described. Benchmarking standards will help users choose proper systems for their applications
and help operators in monitoring machine performance, enabling better control over part building.",,,,,,
"['Al Nabhani, Dawood', 'Kassab, Ali', 'Habbal, Osama', 'Mohanty, Pravansu', 'Ayoub, Georges', 'Pannier, Christopher']",2024-03-25T22:04:26Z,2024-03-25T22:04:26Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124311', 'https://doi.org/10.26153/tsw/50919']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'recycling', 'PLA', '2023 Solid Freeform Fabrication Symposium']",Benchmarking the Tensile Properties of Polylactic Acid (PLA) Recycled Through Fused Granule Fabrication Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc18f980-2e7a-4365-a034-a4c28a2df445/download,University of Texas at Austin,"To progress toward a circular economy of thermoplastic polymers, the adoption of 3D
printers to make functional articles can facilitate distributed recycling. To this end, the
mechanical degradation of polymers through multiple recycling cycles must be quantified. This
work presents a procedure and benchmark dataset of tensile property degradation for polylactic
acid (PLA) feedstock in multiple recycling passes with a fused granule fabrication process. To
establish recycling with minimal processing (shredding and sieving), modifications were
required to the granule feeding hopper of the 3D printer. Two distinct orientations were chosen
to obtain tensile test coupons. These coupons were die-cut from machined 3D printed rectangular
cross-section tubes, with one orientation along the bead (0°) and the other perpendicular to it
(90°). Tensile properties are presented for 3D printed virgin material and one, two, three, and
four passes of recycling. In terms of print orientation, the results indicate that samples pulled at
0° and 90° exhibited similar mechanical properties. However, there was an average decrease of
3.1% in ultimate tensile strength and a 1.7% decrease in elastic modulus for the samples along
90° orientation for all recycling passes. The samples along 0° demonstrated a 13.7% higher
strain at fracture compared to those along 90°. Regarding the number of recycling passes, the
findings suggest that the mechanical characteristics of PLA remain largely unaffected even after
undergoing four recycling cycles. However, when the material is pulled in the direction of the
bead, a 3.09% decrease in ultimate tensile strength is observed in the fourth recycling pass. The
elastic modulus and strain at fracture did not exhibit a clear trend. It is important to note that the
testing results display some variability, which can be attributed to a combination of stochasticity
in the printing process and the preparation procedure employed.",,,,,,
"Walczyk, Daniel F.",2019-02-19T19:36:41Z,2019-02-19T19:36:41Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73435', 'http://dx.doi.org/10.26153/tsw/587']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['RP methods', 'steel laminations']",Bevel Cutting Methods and Cutting Trajectory Control for Steel Laminations Used in Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/270a95fa-92c0-4da3-95da-2293556ce1b2/download,,"Bevel cutting of steel laminations used in profiled-edge laminated tooling allows for a more accurate
representation of the intended die surface, since stair-stepping at the edges is eliminated. Based on experiments
involving maximum cutting speed, bevel angle and kerf quality, the three recommended methods for bevel cutting
steel are (best to worst) pulsed Nd:YAG laser with hard-optic delivery, abrasive water jet, and machining with the
flute edge of an endmill. For each method, bevel angles of up to 80 degrees are possible. Further experimentation
was used to determine the optimal process parameters for kerf quality, with constant cutting speed being one ofthe
main requirements. Finally, a new techIlique to assure constant velocity along the entire lamination cutting trajectory
is developed.",,,,,,
"['Nassar, A.R.', 'Reutzel, E.W.']",2021-10-19T19:10:06Z,2021-10-19T19:10:06Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89326,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'layer-by-layer manufacturing', 'additive manufacturing', 'overhangs', 'Ti-6Al-4V']",Beyond Laser-by-Laser Additive Manufacturing - Voxel-Wise Directed Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15de08ed-f4e7-4206-a0ab-fb7722377a68/download,University of Texas at Austin,"Conventional additive manufacturing is a layer-by-layer process, reliant on the sequential
deposition of 2-1/2 D layers oriented along a build axis. During directed energy deposition a feedstock is directed into a continuous melt pool formed by a laser or electron beam. The ability to
produce overhangs is limited due to the gravitational, surface tensions, and fluid-flow force acting
on unsupported melt pools. Here, we present a novel, directed-energy-deposition technique where
vertical and overhanging structures are formed by laser power modulation and the motion of a
laser beam in three dimensional space along the build-up direction, rather than strictly in a single
layer. We demonstrate that highly-overhanging Ti-6Al-4V structure, i.e. in which the overhang
angle exceeds 45 degrees with respect to the x-y plane, can be deposited using the developed
technique. High-speed imaging is used to gain insight into the physics of the process. The use of
a pulsed or power-modulated beam is found to be critical to the formation of overhangs.",,,,,,
"['Post, Brian K.', 'Richardson, Bradley', 'Lind, Randall', 'Love, Lonnie J.', 'Lloyd, Peter', 'Kune, Vlastimil', 'Rhyne, Breanna J.', 'Roschli, Alex', 'Hannan, Jim', 'Nolet, Steve', 'Veloso, Kevin', 'Kurup, Parthiv', 'Remo, Timothy', 'Jenne, Dale']",2021-11-08T21:14:09Z,2021-11-08T21:14:09Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90043', 'http://dx.doi.org/10.26153/tsw/16964']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['big area additive manufacturing', 'wind turbine molds', 'wind turbine', 'tooling']",Big Area Additive Manufacturing Application in Wind Turbine Molds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4bd41921-cad5-4749-b193-587b24dccb3a/download,University of Texas at Austin,"Tooling is a primary target for current additive manufacturing (AM), or 3D printing,
technology because of its rapid prototyping capabilities. Molds of many sizes and shapes have
been produced for a variety of industries. However, large tooling remained out of reach until the
development of large-scale composite AM manufacturing processes like the Big Area Additive
Manufacturing (BAAM) system. The Department of Energy’s Oak Ridge National Laboratory
(ORNL) worked with TPI Composites to use the BAAM system to fabricate a wind turbine blade
mold. The fabricated wind turbine blade mold was produced in 16 additively manufactured
sections, was 13 meters long, had heating channels integrated into the design, and was mounted
into a steel frame post fabrication. This research effort serves as a case study to examine the
technological impacts of AM on wind turbine blade tooling and evaluate the efficacy of this
approach in utility scale wind turbine manufacturing.",,,,,,
"['Liggett, J.C.', 'Snelling, D.A.', 'Xu, M.', 'Myers, O.J.', 'Thompson, S.M.']",2021-12-06T21:37:22Z,2021-12-06T21:37:22Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90680', 'http://dx.doi.org/10.26153/tsw/17599']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['high chromium white iron', 'bimetallic castings', 'wear performance', 'lattice structures', 'metal additive manufacturing', '316L']",Bimetallic Castings for Wear Performance through Infiltration of Additive Manufactured Metal Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ee9c895-d990-4a67-9e51-1d969aa6aef6/download,University of Texas at Austin,"High chromium white iron is an alloy frequently employed in the production of abrasion
resistive wear components. Ground engaging components for mining or earthmoving frequently
require such materials, as well as slurry pumps for mining applications. Although high chromium
white iron alloy demonstrates excellent wear performance due to the formation of chromium
carbides, it is brittle and lacks toughness. Impact resistance is often of great importance for ground
engaging wear components; hence, this study will investigate a method by which high chromium
white iron wear components may be reinforced by the formation of a bimetallic composite. In this
research, an additively manufactured lattice structure of 316L stainless steel is infiltrated with high
chromium white iron via the metal casting process. This procedure results in a bimetallic casting
of reinforced white iron. Complete infiltration and metallurgical diffusion bonding were observed
between the two alloys, validating this method as a means of reinforcing high chromium white
iron castings for applications requiring high abrasion and impact resistance.",,,,,,
"['Chakravarthy, Kumaran M.', 'Bourell, David L.']",2021-09-30T18:28:16Z,2021-09-30T18:28:16Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88271', 'http://dx.doi.org/10.26153/tsw/15212']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['binder system', 'non metallics', 'bipolar plates', 'SLS', 'graphite-phenolic parts']",Binder Development for Indirect SLS of Non Metallics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e7647de-d636-44fa-8263-3e7abd675c1e/download,University of Texas at Austin,"In this work, a binder system for non metallics such as graphite has been developed and
tested. A graphite-phenolic mixture was used for making bipolar plates using SLS.
Phenolic resin melts (~90°C) instead of cross-linking (~165°C) in the SLS machine.
During post processing in a furnace, the SLS parts slumped due to remelting of phenolic
resin with no other binder present to hold the powder together. To prevent this slumping
and to increase the green strength of the SLS parts, a new binder system was developed
with Nylon/11 added. Nylon/11 has a melting point of ~185°C and is able to hold the
SLS part together until the phenolic can cross link, preventing slumping. Single layer
scan experiments with different compositions and SLS parameters were run to identify
optimum composition and SLS parameters. Three point bend specimens were prepared
with 70 wt. % Graphite-25 wt. % Phenolic- 5 wt. % Nylon/11 and 70 wt. % Graphite-20
wt. % Phenolic- 10 wt. % Nylon/11, tested and compared to graphite-phenolic parts. No
significant increase in green strength was attained with Nylon/11 addition.",,,,,,
"['Volpp, J.', 'Zhang, W.', 'Abbott, W.', 'Coban, A.', 'McConnell, S.', 'Marola, S.', 'Casati, R.', 'Padamati, R.', 'Lupoi, R.']",2024-03-25T23:26:43Z,2024-03-25T23:26:43Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124335', 'https://doi.org/10.26153/tsw/50943']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['powder sheet processing', 'laser materials processing', 'vaporization', 'spatter', 'additive manufacturing']",Binder evaporation during powder sheet Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/64aab548-a645-4f43-b0c4-49de6ce95ab3/download,University of Texas at Austin,"Several Additive Manufacturing methods are well established and found access into regular production in
multiple sectors. For processing metals, typically wire or powder is used as feedstock. Wire processing is typically
used for comparably large structure building, while powder processes offer, in general, a more precise metal
application. For Powder Bed Fusion processes, very fine powder is used (typical 20 µm to 65 µm), while for
Directed Energy Deposition powders are in the range between 50 µm and 160 µm. Such fine powders can be a
health risk for humans (aspiration, skin integration). Avoiding contact with the powders in a production
environment can be a big effort or not avoidable. Therefore, an alternative process was developed that provides
the powder not as free powder particles but in form of powder sheets. For enabling the necessary bonding between
the particles, a binder is used. In order to understand the impact of the binder during laser processing of the powder
sheets, single pulse and line treatments were produced and recorded with high-speed imaging. Recordings show
the vaporization of the binder and the related ejections of powder particles. At lower energy input, the binder
evaporation led to less spattering, which indicates that a binder heating at low heating rates induces less pressure
on the powder particles.",,,,,,
"['Pekin, Senol', 'Zangvil, Avigdor', 'Ellingson, William']",2019-03-01T17:21:42Z,2019-03-01T17:21:42Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73512', 'http://dx.doi.org/10.26153/tsw/662']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['FDC', 'EVA-wax']",Binder Formulation in EVA-wax system for Fused Deposition of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/732d6614-bf6b-46de-84ea-0359e2b6c5ac/download,,"Blends in the ethylene vinyl acetate (EVA) - wax system have been evaluated as potential
binders.to be used in fused deposition of ceramics (FDC). In order to obtain good handling
strength, it was indicated that the melting point of the polymer needs to be lower than that of the
wax. In this context, it was shown that the melting point of the EVA decreases as the vinyl
acetate content in the copolymer increases. By measuring the viscosity as a macroscopic
property, it was shown that 20 % vinyl acetate-containing EVA is miscible in microcrystalline
wax up to, atleast, 30 %.Binders used in FDC need to have low viscosity and it was pointed out
that the slumping can be one main problem associated with binders with low viscosity. Thus,
thermolysis of wax at low temperature is suggested as a solution. The volumetric thermal
expansion and melt strength of an EVA-wax blend were displayed as a function of temperature,
in the form of a penetration test.",,,,,,
"['Agarwal, Kuldeep', 'Vangapally, Sairam', 'Sheldon, Alexander']",2021-11-04T21:05:01Z,2021-11-04T21:05:01Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90028', 'http://dx.doi.org/10.26153/16949']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['binder jet additive manufacturing', 'binder jetting', 'biocomposite', 'tricalcium phosphate', 'stainless steel', 'bone scaffolds', 'implants']",Binder Jet Additive Manufacturing of Stainless Steel - Tricalcium Phosphate Biocomposite for Bone Scaffold and Implant Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c309633c-bad0-4473-aaad-d2304737a420/download,University of Texas at Austin,"Scaffolds are 3D biocompatible structures that mimic the extracellular matrix properties
(mechanical support, cellular activity and protein production) of bones and provide place for cell
attachment and bone tissue formation. Their performance depends on chemistry, pore size, pore
volume, and mechanical strength. Recently, additive manufacturing (AM) has been used as a
means to produce these scaffolds. This paper explores a new biocomposite manufactured using
Binder Jet AM process. Stainless steel and tricalcium phosphate are combined to form a composite
and used in different volume fractions to produce parts with varying densities. Layer thickness,
sintering time and sintering temperature are varied to study the effect of process parameters on the
microstructure, dimensions and mechanical properties of the resulting structure. It is found that the
resulting biocomposite can be tailored by varying the process to change its properties and mimic
the properties of scaffolds in bone tissue applications.",,,,,,
"['Rishmawi, I.', 'Salarian, M.', 'Vlasea, M.']",2021-11-09T14:48:28Z,2021-11-09T14:48:28Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90085', 'http://dx.doi.org/10.26153/tsw/17006']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', 'additive manufacturing', 'irregular iron powder', 'sintering schedule', 'part density']",Binder Jetting Additive Manufacturing of Water-Atomized Iron,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3255ea8e-1696-4572-9ebb-80403c82a6f7/download,University of Texas at Austin,"Binder jetting additive manufacturing (BJAM) was deployed to processing of low-cost, water-atomized
pure iron powder. Surface morphology and particle size distribution of the powder were fully characterized
using scanning electron microscopy (SEM) and particle dynamic image analysis via Retsch Camsizer X2.
Cylindrical samples were fabricated, and in the AM process, the effects of powder compaction, layer
thickness and liquid binder level on green part density were studied. Density analysis was performed
using x-ray computed tomography (µCT). The potential application and future research work will be
outlined based on the characterization results.",,,,,,
"['Caballero, K.', 'Medrano, V.A.', 'Arrieta, E.', 'Sandoval, H.', 'Wicker, R. B.', 'Medina, F.']",2023-04-03T17:42:08Z,2023-04-03T17:42:08Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117727', 'http://dx.doi.org/10.26153/tsw/44606']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Metal Additive Manufacturing', 'Binder Jetting', 'Sintering', 'Simufact Additive', 'Shrinkage']",Binder Jetting of 316L process simulation tools evaluation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99336320-019f-4849-9e81-14de881adc90/download,,"Binder Jetting has become one of the most popular Additive Manufacturing technologies 
over the years due to its low cost and fast production times, nevertheless this technology has a 
steep learning curve due to the shrinkage induced to parts during sintering. Since shrinkage is not 
uniform along the part, it’s hard to efficiently determine what areas will be distorted hence this 
needs to be taken into consideration when designing a new part and many iterations need to be 
printed until dimensional accuracy is achieved, as a result production time and cost significantly 
increase. New Binder Jetting simulation tools are being developed and tested; this software will 
help the technology be more robust and user-friendly for the industry. The software computes a 
sintering simulation and can provide displacement results making support positioning more 
efficient, in addition, newer versions of the software can export a compensated model which will 
be able to be sintered without supports. To evaluate the simulation software, a dimensional test 
artifact model was designed and printed, then compared with the software predicted model 
simulation results. The simulation software was used in an initial evaluation of the test artifact 
geometry to identify areas of concern in the model and document them so efficiency when 
predicting material behavior during the sintering process can be evaluated. In addition, an 
evaluation of the effects of different sintering process parameters on the physical and mechanical 
properties of the material will be analyzed considering the inert sintering atmosphere of the 
process. Finally, printing parameters of the machine such as layer thickness, binder saturation, and 
recoat speed among others will also be evaluated.",,,,,,
"['Diaz-Moreno, Carlos A.', 'Rodarte, C.', 'Ambriz, S.', 'Bermudez, D.', 'Roberson, D.', 'Terrazas, C.', 'Espalin, D.', 'Ferguson, R.', 'Shafirovich, E.', 'Lin, Y.', 'Wicker, Ryan B.']",2021-11-09T14:46:32Z,2021-11-09T14:46:32Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90084', 'http://dx.doi.org/10.26153/tsw/17005']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['ceramics', 'aluminum nitride', '3D components fabrication', 'thermal conductivity', 'binder jetting', 'additive manufacturing']",Binder Jetting of High Temperature and Thermally Conductive (Aluminum Nitride) Ceramic,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7960e4c-eca7-48e4-a4f7-1da3b5a46351/download,University of Texas at Austin,"This work reports on the novel fabrication of aluminum nitride (AlN) complex components using
binder jetting, on the use of sintering and hot isostatic pressing (HIPing) to increase their density,
and on the characterization of the printed material, including thermal conductivity. The HIPing
parameters employed were a temperature of 1900 °C using a rich nitrogen atmosphere at a
pressure of 30,000 psi during 8 h. Results show that the printed and HIPed AlN components had
a 1.96 g/cm3 (60.12%) density when compared to theoretical values. The thermal conductivity
for densified and HIPed components was measured in the range from 23 °C to 500 °C resulting
in values from 4.82 W/m*K to 3.17 W/m*K, respectively. Characterization using scanning
electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction was used to
investigate the ceramic structural morphology of the sintered and HIPed material, its chemical
composition, and crystal structure of the binder jetting manufactured AlN components.",,,,,,
"['Ruprecht, John', 'Agarwal, Kuldeep', 'Ahmed, Shaheen']",2021-11-16T16:05:12Z,2021-11-16T16:05:12Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90326', 'http://dx.doi.org/10.26153/tsw/17247']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['binder saturation', 'layer thickness', 'drying time', 'dimensional tolerance', 'density', 'cobalt chrome', 'tricalcium phosphate', 'biocomposite']","Binder Saturation, Layer Thickness, Drying Time and Their Effects on Dimensional Tolerance and Density of Cobalt Chrome - Tricalcium Phosphate Biocomposite",Conference paper,https://repositories.lib.utexas.edu//bitstreams/2c4450a0-4676-4753-a451-d235a2c2cec8/download,University of Texas at Austin,"Traditional metals such as stainless steel, titanium and cobalt chrome are used in
biomedical applications (implants, scaffolds etc.) but suffer from issues such as osseointegration
and compatibility with existing bone. One way to improve traditional biomaterials is to incorporate
ceramics with these metals so that their mechanical properties can be similar to cortical bones.
Tricalcium phosphate is such a ceramic with properties so that it can be used in human body. This
research explores the use of binder jetting based additive manufacturing process to create a novel
biocomposite made of cobalt chrome and tricalcium phosphate. Experiments were conducted and
processing parameters were varied to study their effect on the printing of this biocomposite. Layer
thickness, binder saturation and drying time affected the dimensional tolerance and the density of
the green samples. This effect is important to understand so that the material can be optimized for
use in specific applications.",,,,,,
"['Bai, Yun', 'Williams, Christopher B.']",2021-11-02T14:55:08Z,2021-11-02T14:55:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89818,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', 'nanoparticles', 'inkjet printing', 'sintering', 'copper']",Binderless Jetting: Additive Manufacturing of Metal Parts via Jetting Nanoparticles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/199dbb02-230a-4e60-a674-b8ebf54da9ab/download,University of Texas at Austin,"Binder Jetting AM has been used to fabricate metal parts by first jetting a binder into
powder bed; the resulting green part is then thermally post-processed wherein the binder is
removed and the metal particles are sintered. In this work, the authors replace conventionally-used polymeric binders with nanoparticle suspensions as a means for binding metal powder bed
particles together. After being deposited into the powder particles’ interstices, the jetted
nanoparticles are sintered at a low temperature via a heated powder bed to provide strength to the
printed green part. Regions of the powder bed that do not receive the jetted nanoparticle
suspension remain as loose powder as the sintering temperature of the nanoparticles is
significantly lower than the larger powder bed particles. The concept of printing metal by jetting
a nanoparticle binder made of the same material is demonstrated in the context of copper through
printing copper parts with satisfactory green strength.",,,,,,
"['Kruth, J. P.', 'Mercelis, P.', 'Froyen, L.', 'Rombouts, Marleen']",2019-12-05T17:23:45Z,2019-12-05T17:23:45Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78651', 'http://dx.doi.org/10.26153/tsw/5707']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Selective Laser,Binding Mechanisms in Selective Laser Sintering and Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d3cc6586-8609-4387-8b0f-d5ebbf5a91d6/download,,"Layer Manufacturing (LM) technologies like Selective Laser Sintering (SLS) were developed
in the late 80’s as techniques for Rapid Prototyping (RP). Today, SLS - as well as its derived
technology Selective Laser Melting (SLM) - is used as well for prototyping, tooling and
manufacturing purposes. This widening of applications is caused mainly by the possibility to
process a large variety of materials, resulting in a broad range of physical and mechanical
properties.
This paper presents a survey of the various binding mechanisms in SLS and SLM, which are
responsible for the broad range of materials and applications. Basic binding mechanisms involve
solid state sintering, chemically induced binding, liquid phase sintering, partial melting and full
melting. Many subcategories can be distinguished based on the type of structural or binder
powder composition: single component powder grains (single material or alloy), composite
powder grains, mixtures of different powder grains, distinct binder material (sacrificial or
permanent), etc. The paper will explain how these binding mechanisms apply for sintering
various types of materials: plastics, metal, ceramics and composites (e.g. glass reinforced
polymers, cermets, hardmetals, etc.). It gives a survey of research done at the University of
Leuven, Belgium, as well as at other European and non-European organizations.",,,,,,
"['Jameekornkul, P.', 'Panesar, A.']",2024-03-27T03:37:55Z,2024-03-27T03:37:55Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124470', 'https://doi.org/10.26153/tsw/51078']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'bouligand fiber arrangement', 'honeycomb structure']",BIO-INSPIRED AM STRUCTURE WITH CARBON FIBRE REINFORCEMENT,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5bfd2951-ff59-4ac7-b35f-3cf905d01146/download,University of Texas at Austin,"This study presents a novel design approach that introduces the bouligand fibre arrangement in a
honeycomb structure. This design is made possible by utilising AM technology which allows for the realisation
of complex design whilst ensuring precise control for fibre placement. Reinforced honeycomb structures with
varied incrementally twisted pitch angle of 0°,1.25°,5° and 15° were successfully fabricated and tested under outof-plane compression. Among the tested angles, the honeycomb structure oriented at 1.25° exhibited higher peak
load and higher specific energy absorption. Unlike the original untwisted honeycomb, the bio-inspired
honeycomb showed no noticeable buckling or delamination at the mid-plane, which may be due the microcracking
or resulting from a delay in crack propagation. However, the precise relationship between pitch angle and
honeycomb properties requires further investigation across a wider range of pitch angle with more focus
understanding the fracture propagation in fibre arrangement. Overall, the preliminary results indicate that the
proposed bio-inspired AM design present a promising approach to enhance the properties of honeycombs and
afford the flexibility to improve toughness and energy absorption capabilities.",,,,,,
"['Guo, Nannan', 'Leu, Ming C.', 'Wu, Maoliang']",2021-10-05T14:39:49Z,2021-10-05T14:39:49Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88382', 'http://dx.doi.org/10.26153/tsw/15321']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['fuel cells', 'polymer electrolyte membrane', 'flow fields', 'bipolar plate', 'finite element modeling']",Bio-Inspired Design of Bipolar Plate Flow Fields for Polymer Electrolyte Membrane Fuel Cells,Conference paper,https://repositories.lib.utexas.edu//bitstreams/142c716a-8625-4cbd-a51c-b749d74fe960/download,University of Texas at Austin,"The flow field of a bipolar plate distributes hydrogen and oxygen for polymer electrolyte
membrane (PEM) fuel cells and removes the produced water from the fuel cells. It greatly
influences the performance of fuel cells, especially regarding reduction of mass transport loss.
Flow fields with good gas distribution and water removal capabilities reduce the mass transport
loss, thus allowing higher power density. Inspired by natural structures such as veins in tree
leaves and blood vessels in lungs, which efficiently feed nutrition from one central source to
large areas and are capable of removing undesirable by-products, a mathematic model has been
developed to optimize the flow field with minimal pressure drop, lowest energy dissipation, and
uniform gas distribution. The model can be used to perform optimal flow field designs, leading
to better fuel cell performance for different sizes and shapes of bipolar plates. Finite element
modeling (FEM) based simulations and in-situ experiments were conducted to verify some of the
flow field designs obtained using the developed mathematic model.",,,,,,
"['Lee, G.', 'Barlow, J.W.', 'Fox, W.C.', 'Aufdermorte, T.B.']",2018-11-08T19:14:05Z,2018-11-08T19:14:05Z,1996,Mechanical Engineering,doi:10.15781/T2S46HR8S,http://hdl.handle.net/2152/69907,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'MRI', 'reconstruction']",Biocompatibility of SLS-Formed Calcium Phosphate Implants,Conference paper,https://repositories.lib.utexas.edu//bitstreams/907f6f0a-3cf2-4291-8891-429666d4a170/download,,"A method for fabricating artificial calcium phosphate bone implants by the Selective Laser
Sintering (SLS) process has been developed that can fabricate complex and delicate
calcium phosphate bone facsimiles from a variety of data inputs including Computed
Tomography(CT) files (1). This paper discusses two in vivo biocompatibility studies of
SLS-formed calcium phosphate implants in both rabbits and dogs. Histologic analysis
shows a high degree of biocompatibility and bone ingrowth in both studies.",,,,,,
"['He, Yinfeng', 'Kilsby, Sam', 'Tuck, Chris', 'Wildman, Ricky', 'Christie, Steven', 'Yang, Hongyi', 'Edmondson, Steven']",2021-10-18T21:21:06Z,2021-10-18T21:21:06Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89249,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['biodegradable polycaprolactone based ink', 'biodegradable polycaprolactone', '3D inkjet printing', 'Additive Manufacturing', 'biomedical applications']",A Biodegradable Polycaprolactone Based Ink Developed for 3D Ink Jetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/992bc183-550a-476b-b002-195c4048623a/download,University of Texas at Austin,"Biomedical applications are one of the driving forces for Additive
Manufacturing, however to extend the range of applications and markets new
materials are required. A new type of biodegradable Polycaprolactone (PCL) based
ink that is suitable for 3D inkjet printing was successfully developed. UV curable PCL
was synthesized and mixed with Poly(ethylene glycol) di-acrylated (PEGDA) to
prepare an ink with suitable viscosity for inkjet printing. Their mechanical properties
as well as the printing accuracy were measured by nano-indentation and scanning
electron microscopy. Post curing was applied to printed samples in order to study
how post curing may influence sample properties. It was found that within 30min
post-curing period, the sample’s surface which is direct illuminated by UV light
increased from 31.22MPa to 70.20MPa while the bottom surface showed less
incensement from 34.9MPa to 39.8MPa.",,,,,,
"['Starly, B.', 'Lau, A.', 'Sun, W.', 'Lau, W.', 'Bradburyq, T.']",2020-02-17T15:36:54Z,2020-02-17T15:36:54Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80012', 'http://dx.doi.org/10.26153/tsw/7037']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Interior Architecture Design,Biomimetic Design and Fabrication of Interior Architecture of Tissue Scaffolds Using Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85971b3e-5d43-4c7e-8621-6836b4756151/download,,"Modeling, design and fabrication of tissue scaffolds with intricate architecture,
porosity and pore size for desired tissue properties presents a challenge in tissue engineering.
This paper will present the details of our development in designing and fabrication of the
interior architecture of scaffolds using a novel design approach. The Interior Architecture
Design (IAD) approach seeks to generate scaffold layered freeform fabrication tool path without
forming complicated 3D CAD scaffold models. This involves: applying the principle of layered
manufacturing to determine the scaffold individual layered process planes and layered contour;
defining the 2D characteristic patterns of the scaffold building blocks (unit cells) to form the
Interior Scaffold Pattern; and the generation of process tool path for freeform fabrication of
these scaffolds with the specified interior architecture. Feasibility studies applying the IAD
algorithm to example models and the generation of fabrication planning instructions will be
presented.",,,,,,
"['Delwiche, Maia', 'Obielodan, John']",2023-02-10T13:51:54Z,2023-02-10T13:51:54Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117446', 'http://dx.doi.org/10.26153/tsw/44327']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Biopolymer', 'Dairy', 'Casein', 'Polymers']",Biopolymer Composites with Dairy Protein for Use in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/020f269d-1ed1-47e7-84f1-da571b902c97/download,,"As the popularity and versatility of additive manufacturing grows, so does interest in 
developing new materials, including biopolymers. Casein is a protein found in dairy and 
historically, has been used in food applications, but its use as a biomaterial for engineering 
structures is less common. This study investigates the development of composite materials for 
additive manufacturing with casein as a biomaterial filler. To observe the effects of casein on 
material properties, vat photopolymerization-based and fused filament fabrication-based matrix 
materials were combined with different weight fractions of casein. Test samples were fabricated 
to evaluate tensile properties. Test results show a maximum increase of 4% for FFF and 34% for 
SLA in the stiffness of the materials with casein compared to the neat matrix materials. However, 
the composite materials showed between 12% and 54% reductions in ductility, and marginal 
decreases in tensile strengths. The preliminary results indicate viability and prompt further 
investigation into casein-polymer composites for additive manufacturing.",,,,,,
"['Hoeges, S.', 'Lindner, M.', 'Meiners, W.', 'Smeets, R.']",2021-10-04T19:58:13Z,2021-10-04T19:58:13Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88330', 'http://dx.doi.org/10.26153/tsw/15269']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['bioresorbable implants', 'bone implants', 'additive manufacturing', 'Selective Laser Melting', 'bone surgery']",Bioresorbable Implants using Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e45a9a14-577d-4df0-be76-1d395bbcc2fb/download,University of Texas at Austin,"Using bioresorbable materials implants can be manufactured which dissolve in the human body
and are replaced by natural bone structure. For large implants an interconnecting porous structure
needs to be integrated in the implant for a good vascularisation. Using additive manufacturing
technology these internal structures can be directly manufactured. The structure can be designed
by consequent following the guidelines of the medical expert. This paper describes the development of Selective Laser Melting to process bioresorbable materials Poly(D,L-lactide) and B-Tricalciumphosphate. The properties of the parts concerning microstructure, mechanical and
biological properties after processing are analyzed in laboratory and animal tests. Possible
applications are demonstrated and include individual bone substitute implants in cranio-maxillofacial surgery.",,,,,,
"['Liu, J.', 'Fearon, E.', 'Edwardson, S.P.', 'Dearden, G.']",2021-11-04T14:12:12Z,2021-11-04T14:12:12Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89965,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['blown powder laser cladding', 'processing parameters', 'isotropic material', 'build height', 'powder delivery rate', 'additive manufacturing']",Blown Powder Laser Cladding with Novel Processing Parameters for Isotropic Material Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ebca7c3-6294-449d-948f-fef4e264b524/download,University of Texas at Austin,"A limitation for blown powder laser additive manufacturing in many applications is the
material properties of parts made tend to show anisotropy due to directional solidification of
the microstructure. Recent work reported here has identified novel low power processing
conditions that yield equiaxed grain structures in 316L stainless steel and thus potentially
eliminate material anisotropy. Initial observations show that the process window is affected by
build height, substrate choice, powder, powder delivery rates, laser power and processing speed.
A system has been developed to give precision layer height control via nozzle design and low
powder delivery rates through an in-house design of powder hopper. Mechanical tests have
been conducted under the novel processing parameters. Large amounts and uniform
distribution of equiaxed structures compared to standard process conditions in 316L are found
significantly. Moreover, cladding has been successfully produced with significantly low power
around 350W, thus potentially improving process efficiency and set-up cost.",,,,,,
"['Sriraman, M.R.', 'Hiromichi, Fujii', 'Gonser, Matt', 'Babu, S.S.', 'Short, Matt']",2021-09-30T15:27:12Z,2021-09-30T15:27:12Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88263', 'http://dx.doi.org/10.26153/tsw/15204']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Very High Power Ultrasonic Additive Manufacturing', 'aluminum alloys', 'copper alloys', 'layer bonding']",Bond Characterization in Very High Power Ultrasonic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1996184-5392-463a-b2bb-abc35960ffd3/download,University of Texas at Austin,"Solid parts were produced by Very High Power Ultrasonic Additive Manufacturing (VHP-UAM)
at room temperature using 150 μm thick tapes of 6061 aluminum and 110 copper alloys.
Processing was done at 20 kHz frequency over a range of parameters (26 –36 μm vibration
amplitude, 5.6 – 6.7 kN normal force, and 30.5 - 35.5 mm/s travel speed). Softening of materials
(up to about 14% in 6061 Al and 23% in 110 Cu) was noted facilitating enhanced plastic flow
and a reduction in interfacial voids. Evolution of fine recrystallized grains (0.3-4 μm in 6061 Al
and 0.3-10 μm in 110 Cu) from an initial coarser grain structure (up to 8 μm in 6061 Al and 25
μm in Cu) was observed at the build interface regions. Bonding between layers in both materials
seems to have occurred by dynamic recrystallization and movement of grain boundaries across
the interface. The energy required for the above physical processes is derived from interfacial
adiabatic plastic deformation heating.",,,,,,
"['Walczyk, Daniel F.', 'Dolar, Nathanael Y.']",2018-11-29T21:00:36Z,2018-11-29T21:00:36Z,1997,Mechanical Engineering,doi:10.15781/T2QR4P95D,http://hdl.handle.net/2152/70344,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['welding', 'laminations']",Bonding Methods for Laminated Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1be7e4e5-c0bb-4ae3-9353-0aef1950a707/download,,"Laminated tooling consists of an array of stacked laminations that are mechanically
clamped or bonded together, depending on the requirements of the manufacturing process.
Various manufacturing processes that can benefit from tooling constructed oflaminations include
sheet metal forming, thermoforming, composites molding, metal extrusion, injection molding,
resin transfer molding, and compression molding. When bonding of the laminations is required
(e.g., incorporation of conformal cooling passages for injection molding temperature control)
then laminations can be joined together by diffusion bonding, brazing and using adhesives.
However, for a tooling engineer to effectively design a laminated tool, the physical and
mechanical properties of these joints must be known. Consequently, a set of experiments is
outlined for determining the tensile, shear, and peel strengths, tensile and shear elastic moduli,
thermal contact resistance, and specific permeability (for gasses or liquids) ofthe aforementioned
bonded joints for both steel and aluminum laminations. Some preliminary results with aluminum
and future work are presented.",,,,,,
"['Ott, M.', 'Meihöfener, N.', 'Koch, R.']",2023-03-30T16:06:43Z,2023-03-30T16:06:43Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117696', 'http://dx.doi.org/10.26153/tsw/44575']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Boosting artificial intelligence in design processes by the use of additive manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c06599a6-b454-48f6-a52a-3e09575c2438/download,,"Additive manufacturing offers the option of converting digital prototypes into real 
structures as quickly as possible by the special property of tool-free manufacturing. However, this 
process can only be used at optimum speed if bottlenecks can be effectively avoided. One of these 
constraints is the design process. Although modern CAD systems allow a significant increase in 
many areas, this always requires a person with specific skills (e.g. engineer). In the field of AM in 
particular, more and more powerful software solutions have recently been published which 
accelerate the Design for Additive Manufacturing, including most CAD-tasks. In many areas, 
therefore, attempts are already made to automate relevant design steps as much as possible, more 
and more using neural networks and artificial intelligence. This paper presents how and why such 
techniques can be used to generate three-dimensional structures quickly and efficiently in cases of 
deep generative design tasks.",,,,,,
"['Lipton, Jeffrey I.', 'Cohen, Daniel', 'Lipson, Hod']",2021-09-29T18:04:36Z,2021-09-29T18:04:36Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88203', 'http://dx.doi.org/10.26153/tsw/15144']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['brick printing', 'modular architectural elements', 'embedded systems', 'open-architecture SFF']",Brick Printing: Freeform Fabrication of Modular Architectural Elements with Embedded Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/72ca5735-3301-4bab-89e8-83ebca726a1e/download,University of Texas at Austin,"We propose the use of modular, printed bricks to enable the integration of building
systems and various processing techniques through the use of scalable printer
platforms. This is enabled by a novel material platform comprised of clay, gypsum
cement, FabEpoxy™, and SS-26F conductive silicone. On an open-architecture SFF
system, a segment of cement wall with embedded electrical and fluidic conduits and
various processing techniques was fabricated. Electrical and fluidic tolerances were
comparable to traditionally constructed systems.",,,,,,
"['Luo, Junjie', 'Bender, Theresa', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Goldstein, Jonathan T.', 'Urbas, Augustine M.', 'Kinzel, Edward C.']",2021-10-28T14:31:28Z,2021-10-28T14:31:28Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89650,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['bubble formation', 'bubble entrapment', 'borosilicate glass', 'additive manufacturing']",Bubble Formation in Additive Manufacturing of Borosilicate Glass,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b97f2f04-6bed-4f4d-bbad-32cbae205df8/download,University of Texas at Austin,"Entrapped bubbles are an important problem in conventional glass manufacturing. It is also a significant
factor determining the quality of glass products produced using additive manufacturing (AM). This paper
reports on the bubble formation and entrapment in filament-fed AM printing of borosilicate glass. This process
involves maintaining a local molten region using a CO2 laser. A 2 mm filament is fed continuously into the
molten region while CNC stages position the workpiece relative to the laser and filament feed. Two different
bubble regimes are identified in experiments with borosilicate glass. These regimes can be related to different
physical phenomena, specifically, bubble entrapment at defects in the filaments and bubble formation due to
reboil. These can be overcome by selecting defect free filaments and by minimizing the temperature inside the
molten region to prevent breaking down the glass. Understanding these mechanisms allows bubble-free glass to
be printed. Finally, residual stress in the deposited glass pieces is removed using post-deposition annealing and
validated using a polariscope.",,,,,,
"['Roschli, Alex', 'Post, Brian K.', 'Atkins, Celeste', 'Stevens, Adam G.', 'Chesser, Phillip', 'Zaloudek, Kristin']",2023-01-27T13:59:03Z,2023-01-27T13:59:03Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117333', 'http://dx.doi.org/10.26153/tsw/44214']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['build plate', 'build surface', 'extrusion', '3D printer design']",Build Plate Design for Extrusion-Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eee89ba5-c62e-4bfc-a37a-b274a21b27ee/download,,"A fundamental part of machine design for large format polymer extrusion-based additive 
manufacturing (AM) systems is the substrate where the object is to be constructed, often referred 
to as the build plate. A good build plate is imperative for a successful build as it is used for 
supporting and positioning the part during the entire construction. For planar 3D printing, this 
build plate needs to be flat and in-plane with the X/Y motion of the 3D printer. Additional 
functionality can include heaters for preventing delamination or warping, vacuum to help prevent 
warping, removable build surfaces for quick part removal, and mounting features for helping 
position a part for subtractive operations. This paper reviews existing build plate designs and 
discusses the design considerations and materials for build plate fabrication.",,,,,,
"['McClurkin, Joel E.', 'Rosen, David W.']",2018-12-07T16:06:52Z,2018-12-07T16:06:52Z,1997,Mechanical Engineering,doi:10.15781/T2HD7PC8K,http://hdl.handle.net/2152/71442,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SLA', 'Build Style Optimization']",Build Style Decision Support for Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbe2b51b-3e0e-4fbf-ab0b-a15815fd48d8/download,,"When building parts in a stereolithography apparatus (SLA), the user is faced with many
decisions regarding how the part will be built. The quality of the build can be controlled by the
user via changing one of several build style variables, including part orientation, cross sectional
layer thickness, and laser hatch density. A user will probably have preferences for the part build
(Le., accuracy or speed), but may not understand how to vary the build style variables to produce
the desired results. A method based on response surface methodology and multi-objective decision
support is described in this paper for relating build goals to three build style variables, and the use
ofthese relationships in providing decision support for building a part on a SLA. The method is
applied to the build style of a circuit breaker handle.",,,,,,
"['Mensing, G.', 'Gibson, I.']",2019-02-22T19:58:47Z,2019-02-22T19:58:47Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73468', 'http://dx.doi.org/10.26153/tsw/618']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping systems', 'StereoLithography']",Build Time Estimations for Large Scale Modelling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9ccdbc7-9a63-431f-92ca-a285750f03c1/download,,"Achieving speedy results in model making is very much desired if not a necessity in ahnost any
manufacturing industry. There is no doubt that rapid prototyping contributes to this process. It is
generally considered that when compared to conventional machining techniques like nlilling, the
current rapid prototyping systems appear to be much faster. This is certainly true for complex,slnall
objects. I-Iowever, this is not alwaysa,pplicable to simple, large and bulky parts.
There are a number of projects and systems concentrating on the fabrication of large models. Work
is being carried out at the University ofHong Kong, using milling. along with slicing technology.
This.report compares some ofthe rapid prototyping systems witl1milling. Milling is an established
technology and recent developments in materials and nlachines used in Inilling nlake it a good
alternative to rapid prototyping when itcomes to largesyale nl0delling.",,,,,,
"['Li, Yingqi', 'Shen, Yiyu', 'Leu, Ming C.', 'Tsai, Hai-Lung']",2021-11-02T19:46:04Z,2021-11-02T19:46:04Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89880,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['metallic glass', 'titanium', 'laser welding', 'embrittlement', 'additive manufacturing']",Building Zr-Based Metallic Glass Part on Ti-6Al-4V Substrate by Laser-Foil-Printing Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/facfccd8-bb78-4ef6-b4b6-3892c4656cb0/download,University of Texas at Austin,"Through using Zr intermediate layers, Zr52.5Ti5Al10Ni14.6Cu17.9 metallic glass (MG) parts are
successfully built on Ti-6Al-4V substrate by laser-foil-printing (LFP) additive manufacturing
technology in which MG foils are laser welded layer-by-layer onto the substrate. The printed MG
part is free of porosity, cracking and crystallization, and its properties are very similar to the
original MG material. The Zr intermediate layers are aimed at preventing direct interaction
between the first layer of MG foil and the Ti substrate; otherwise, the welded MG foils would peel
off from the substrate due to the formation of brittle intermetallic compounds. With the use of Zr
intermediate layers, the bonding strength of the printed MG part and the Ti substrate can reach 758
MPa owing to the formation of α-Zr phase.",,,,,,
"['Choi, Sangeun', 'Hebbar, Ravi', 'Zheng, Yong', 'Newman, Wyatt S.']",2018-12-07T16:11:52Z,2018-12-07T16:11:52Z,1997,Mechanical Engineering,doi:10.15781/T2804Z53B,http://hdl.handle.net/2152/71444,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SDM']",CAD and Control Technologies for Computer-Aided Manufacturing of Laminated Engineering Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/74d442b8-0888-4062-8bac-8b51d3cd162a/download,,"This paper presents recent progress in software, material handling and tangent-cutting control in
support of Computer-Aided Manufacturing of Laminated Engineering Materials(CAM-LEM).
Progress in CAD focuses on the definition of a new layered file format for describing 3-D solids in
terms of thick slabs with ruled-surface edges. For material handling, we present new algorithms
for automatic generation of mask hole patterns used in selective-area vacuum gripping, which is
required for our laminated assembly process. Finally, we present recent results of object
fabrication using thick-slab, tangent-cut layers",,,,,,
"['Koch, P.', 'Korn, H.', 'Kordass, R.', 'Holtzhausen, S.', 'Schoene, C.', 'Mueller, B.', 'Stelzer, R.']",2021-11-09T20:22:10Z,2021-11-09T20:22:10Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90156', 'http://dx.doi.org/10.26153/tsw/17077']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['CAD-based workflow', 'CAD', 'mechanical characterization', 'lattice structures', 'laser beam melting', 'additive manufacturing']",A CAD-Based Workflow and Mechanical Characterization for Additive Manufacturing of Tailored Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2854ec4-ff96-42cc-8521-536b58fcf0ac/download,University of Texas at Austin,"Lattice structures are highly recommended for lightweight applications and cost reduction
in additive manufacturing (AM). Currently, parts with lattice structures are still mainly used for
illustrative purposes and rarely in industrial products. One important reason is that, due to their
high dependency on macro- and micro-geometry, the mechanical properties of manufactured
structures are difficult to predict. Thus, even and precise struts are needed. In this paper, a workflow
for fabrication of lattice structures with strut-diameters from 150 µm to 400 µm on commercial
laser beam melting (LBM) systems is presented. Based on a CAD-integrated user-interface for
lattice design, a customized slicing algorithm determines database-aided suitable exposure
parameters which ensure that the properties of the manufactured struts will just be as specified
upon design. Subsequently, compression tests are performed in order to verify the established
workflow. The developed tool enables designers to integrate AM-specific geometries into their
components with little specific experience in AM.",,,,,,
"['Quigley, Tiffany', 'Penney, Joshua', 'Goodspeed, Devon', 'Cornelius, Aaron', 'Hamel, William', 'Schmitz, Tony', 'Jared, Bradley']",2023-01-26T14:58:16Z,2023-01-26T14:58:16Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117313', 'http://dx.doi.org/10.26153/tsw/44194']",eng,2022 International Solid Freeform Fabrication Symposium,Open,WAAM,CAD-to-Scan Planning for Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/88468c5b-da74-442e-9dca-41587730f8c5/download,,"The University of Tennessee, Knoxville (UT) has developed a hybrid manufacturing work 
cell incorporating wire-arc additive manufacturing (WAAM), fringe projection scanning and 5-
axis machining. Integrating metrology into the hybrid manufacturing work cell enables 
optimization of printed part placement for machining and/or supplementary material, when 
necessary, via additional deposition. This presentation will explore path planning for efficient 
imaging of printed geometries. The acquired scans are then polygonized and compared to the 
desired geometry which is utilized in defining machining areas with excess material or underbuilt 
areas for additional material deposition via gas metal arc welding (GMAW).",,,,,,
"['Zhou, Chi', 'Chen, Yong']",2021-09-28T18:45:32Z,2021-09-28T18:45:32Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88150', 'http://dx.doi.org/10.26153/tsw/15091']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'large-area mask projection stereolithography', 'digital light processing', 'calibration']",Calibrating Large-area Mask Projection Stereolithography for Its Accuracy and Resolution Improvements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/94990696-ae14-459e-bf8d-91514dfb1d16/download,University of Texas at Austin,"Solid freeform fabrication (SFF) processes based on mask image projection such as digital
micro-mirror devices (DMD) have the potential to be fast and inexpensive. More and more research
and commercial systems have been developed based on such digital devices. However, a digital light
processing (DLP) projector based on DMD has limited resolution and certain image blurring. In order
to use a DLP projector in the large-area mask projection stereolithography, it is critical to plan mask
images in order to achieve high accuracy and resolution. Based on our previous work on optimized
pixel blending, we present a calibration method for capturing the non-uniformity of a projection image
by a low cost off-the-shelf DLP projector. Our method is based on two calibration systems, a
geometric calibration system that can calibrate the position, shape, size, and orientation of a pixel and
an energy calibration system that can calibrate the light intensity of a pixel. Based on both results, the
light intensity at various grayscale levels can be approximated for each pixel. Developing a library of
such approximation functions is critical for the optimized pixel blending to generate a better mask
image plan. Experimental results verify our calibration results.",,,,,,
"['Torabi, Payman', 'Petros, Matthew', 'Khoshnevis, Behrokh']",2021-10-12T22:20:23Z,2021-10-12T22:20:23Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88754', 'http://dx.doi.org/10.26153/tsw/15688']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Inhibition Sintering', 'Additive Manufacturing', 'piezo-electric printhead', 'metal parts', 'Design of Experiments']",Calibration of a Piezo-Electric Printhead in the Selective Inhibition Sintering (SIS) Process for Fabrication of High Quality Metallic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/30e6d444-6ac0-4faf-bb6d-c4b2533c28ed/download,University of Texas at Austin,"Selective Inhibition Sintering (SIS) is a disruptive Additive Manufacturing process capable of
printing parts from polymers, metals and ceramics. In this paper the application of a commercial
piezo-electric printhead in SIS-metal is studied. This replaces the single-nozzle solenoid valve
previously used in the process and allows the fabrication of high quality metallic parts due to
smaller droplet sizes as well as high resolution printing mechanisms. A Design of Experiments
(DoE) approach has been utilized to study the effects of important factors in printing the
inhibitor. These factors include: composition of the inhibitor, quality of the print, and amount of
fluid deposited for each layer. Based on the results of these experiments, parameters have been
identified for the creation of highly accurate three-dimensional parts.",,,,,,
"['Rangapuram, M.', 'Dasari, S.K.', 'Isanaka, S.P.', 'Buchely, M.F.', 'Newkirk, J.W.', 'Chandrashekhara, K.']",2023-03-30T16:09:16Z,2023-03-30T16:09:16Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117697', 'http://dx.doi.org/10.26153/tsw/44576']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Calibration of the Johnson-Cook Material Model for Additively  Manufactured 304L SS Parts: Modeling and Experiments,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9b9d708a-c1db-4c0c-a451-32809c81f71d/download,,"Selective laser melting (SLM) is a type of additive manufacturing technique which uses a powder 
bed to form complex metal parts in a layer-by-layer process. This study aims to understand the 
material flow of parts manufactured by SLM process using 304L stainless steel powder, which is 
widely used in numerous applications. The tensile specimens were manufactured using 304LSS 
powder through SLM process. Low strain-rates, high temperature tensile tests were carried out to 
calibrate the parameters of the constitutive Johnson-Cook strength model. To conduct the tensile 
tests, different temperatures (25 

oC, 150 oC and 250 oC) and strain-rates (0.1 s-1, 0.01 s-1 and 0.001 

s-1) were used. The material model developed was used in numerical simulation of the tensile tests 
and compared with the experimental results.",,,,,,
"['Liu, z. E.', 'Ko, T. C.', 'Bes, J.', 'Cawley, J. D.', 'Heuer, A. H.']",2018-12-05T18:00:46Z,2018-12-05T18:00:46Z,1997,Mechanical Engineering,doi:10.15781/T2930PF6W,http://hdl.handle.net/2152/71404,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAM', 'LEM']",CAM-LEM Processing: Materials Flexibility,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63157cf4-333c-4e65-8fca-3174694a4833/download,,"The cut-then-stack paradigm of computer-aided manufacturing of laminated engineering
materials (CAM-LEM) offers choice of feedstock material, ease of handling finely divided (and
therefore sinterable) powders, and the ability to mix materials. This combination of features was
exploited to process fluidic devices. CAM-LEM processing was used to render the Part in
aluminum oxide, silicon nitride, and stainless steel.",,,,,,
"['Lade, Robert K. Jr', 'Hippchen, Erik J.', 'Rodgers, Luke', 'Macosko, Christopher', 'Francis, Lorraine F.']",2021-10-21T22:07:15Z,2021-10-21T22:07:15Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89457,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'capillary flow', 'microchannel', 'flow dynamics']",Capillary-Driven Flow in Open Microchannels Printed with Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e98325a-af43-4f0b-8392-09358f0e3a81/download,University of Texas at Austin,"The fundamentals of fluid flow in 3D printed, open microchannels created using fused
deposition modeling (FDM) are explored. Printed microchannels are used in microfluidic devices
and have potential applications in embedding electronics in plastic substrates. However, FDM
parts possess rough surfaces, and in this study, surface topography is shown to have an important
impact on flow behavior, causing the liquid to travel down the channel with a characteristic
‘pulsing’ movement. We also analyze the influence of print orientation on capillary flow, where
microchannels printed in specific orientations are shown to exhibit different flow dynamics.",,,,,,
"['Basak, Amrita', 'Das, Suman']",2021-10-26T19:56:33Z,2021-10-26T19:56:33Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89569,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['MAR-M247', 'nickel-based superalloys', 'scanning laser epitaxy', 'carbide formation']",Carbide Formation in Nickel-Base Superalloy MAR-M247 Processed Through Scanning Laser Epitaxy (SLE),Conference paper,https://repositories.lib.utexas.edu//bitstreams/d1203693-1870-4cf3-8ee7-e62dc4af5d63/download,University of Texas at Austin,"Nickel-base superalloys develop high-temperature strength primarily due to the solid-solution-strengthening and the precipitation-strengthening mechanisms typically through cobalt/chromium
and aluminum/titanium respectively. Certain other elements such as boron and zirconium are
chosen for grain boundary strengthening. Such elements tend to segregate to the grain boundaries
reducing the grain boundary energy and resulting in better grain boundary cohesion and ductility.
Another form of grain boundary strengthening is achieved through the addition of carbon and
various carbide formers. The carbide formers are responsible for driving precipitation of carbides
at grain boundaries and thereby reducing grain boundary sliding. Various types of carbides such
as blocky, elongated, and Chinese-script are possible in the microstructures of nickel-base
superalloys depending on the composition of the superalloy and processing conditions. However,
in the SLE fabricated MAR-M247, only blocky carbides were predominantly observed. Scanning
electron microscopy and energy dispersive X-ray spectroscopy investigations were carried out and
the carbides were found to be tantalum-rich.","This work is sponsored by the ONR through grant
N00014-14-1-0658.",,,,,
"['Bai, Jiaming', 'Goodridge, Ruth D.', 'Hague, Richard J.M.', 'Song, Mo']",2021-10-05T15:50:36Z,2021-10-05T15:50:36Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88397', 'http://dx.doi.org/10.26153/tsw/15336']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'polymer nanocomposites', 'processing parameters', 'thermal conductivity']",Carbon Nanotube Reinforced Polyamide 12 Nanocomposites for Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd4ade4e-4d0c-407e-ad28-babd4f450a59/download,University of Texas at Austin,"In this work, Polyamide12 (PA12) and Carbon nanotube (CNT) added PA12-CNT
nanocomposites were laser sintered and investigated. The powder morphology and CNT
dispersion of the PA12-CNT were examined. Laser sintering process parameters: powder bed
temperature and laser power were studied and optimised. The effect of the addition of CNT on
the thermal properties of PA12 was identified. Compared to the laser sintered parts produced
from commercially available laser sintering PA12 powder, the laser sintered PA12-CNT parts
showed increased tensile modulus and tensile strength.",,,,,,
"['Jost, Elliott', 'Berez, Jaime', 'Saldaña, Christopher']",2023-02-17T14:42:38Z,2023-02-17T14:42:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117485', 'http://dx.doi.org/10.26153/tsw/44366']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,A Case Study in Component Redesign for Additive Manufacturing Process Workflows,Conference paper,https://repositories.lib.utexas.edu//bitstreams/00a7bd69-bba3-497e-94ee-a0d6934fd32a/download,,"Additive manufacturing (AM) has matured beyond limited use-cases in rapid prototyping 
into a process capable of competing with conventional manufacturing methods in the production 
of end-use components. As such, many manufacturers are evaluating candidate products for 
redesign for AM, with interest in improving component performance, streamlining manufacturing, 
and reducing costs. In this study, the authors argue for systematic use of opportunistic design tools 
such as generative design and for the inclusion of restrictions imposed by the entire manufacturing 
process workflow to be included in the design process. Emphasis is placed on how secondary 
processing steps, that is, those other than the primary AM process, inform design. A bicycle stem 
is used as an exemplar case study of component redesign for AM. Generative design is used to 
optimize the component’s weight given the design constraints. An end-to-end manufacturing 
process chain is consequently developed and analyzed for viability, covering design for additive 
manufacturing (DFAM) and post processing. Through this comprehensive case study, it is shown 
that significant weight savings, greater than 25% in the present case, can be achieved through the 
DFAM process. Guidelines from the DFAM process are generalized for application to further 
cases.",,,,,,
"Aubin, Richard F.",2018-04-19T18:09:14Z,2018-04-19T18:09:14Z,1992,Mechanical Engineering,doi:10.15781/T2HT2GV4P,http://hdl.handle.net/2152/64397,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['UTC', 'United Technologies Corporation', 'Pratt & Whitney']",A Case Study in Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dbdfed3a-5712-4bc5-9b7e-062bbbc9b641/download,,"Since the first quarter of 1988, Pratt & Whitney (P&W), a Division of United Technologies
Corporation (UTC), has been involved in the development for the use of rapid prototyping
technologies that use a ""layer-by-Iayer"" building approach. Based on over 4 1/2 years
experience with Stereolithography, this paper will address three aspects of our experience
including: Implementation, Current Operations, and Future Plans",,,,,,
"['Zhang, Haiou', 'Li, Runsheng', 'Wang, Rui', 'Fu, Youheng', 'Wang, Xiangping', 'Wang, Guilan', 'Tang, Shangyong']",2021-11-04T18:40:33Z,2021-11-04T18:40:33Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90000', 'http://dx.doi.org/10.26153/16921']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['casting-forging-milling composite', 'CFMC', 'additive manufacturing technology', 'additive manufacturing']",Casting - Forging - Milling Composite Additive Manufacturing Thechnology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cca03cb7-d3a9-4f78-9c51-c7ac51d5212f/download,University of Texas at Austin,"The current metal additive manufacturing has some drawbacks, such as poor performance in producing
forgings, low accuracy and efficiency, and high cost. This paper proposes a new technology called casting-forging-milling composite (CFMC) additive manufacturing, which uses the efficient and cheap arc as the heat
source. Synchronous arc welding and continuous semi-solid in-situ forging is achieved with micro-roller.
Milling is incorporated into this process to remove defects and complete the part. Workpieces with equiaxed
fine-grained microstructure and better performance than forgings have been obtained using CFMC. Testing
shows that the mechanical performance exceeds the standards for forgings and most indicators are above the
average levels. Trial products include titanium alloy aeronautical parts, a stainless steel propeller, and an aero-engine transition section which has passed the European standard x-ray inspection and test. The streamlined and
low-cost manufacturing process achieved by using metal wire, integrated equipment and low pressure makes
CFMC a green manufacturing model.",,,,,,
"['Gopal, Arjun', 'Parihar, Gaurav', 'Holt, McKay', 'Stinson, Tanner', 'Sharma, Manasvi', 'Bhate, Dhruv']",2021-11-30T19:44:25Z,2021-11-30T19:44:25Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90525', 'http://dx.doi.org/10.26153/tsw/17444']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'cellular optimization', 'topology optimization', 'beams', 'bending', 'design for additive manufacturing']",Cellular and Topology Optimization of Beams under Bending: An Experimental Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f48d6317-c69d-4629-80a0-3c2ddf8bc43b/download,University of Texas at Austin,"Design for Additive Manufacturing (AM) includes concepts such as cellular materials and
topology optimization that combine the capabilities of advanced computational design with those
of AM technologies that can realize them. There is however, limited experimental study of the
relative benefits of these different approaches to design. This paper examines these two different
approaches, specifically in the context of maximizing the flexural rigidity of a beam under
bending, while minimizing its mass. A total of 23 beams were designed using commercially
available cellular design, and topology optimization software. The Selective Laser Sintering (SLS)
process was used to manufacture these beams with Nylon 12, which were then tested per ASTM
D790 three-point bend test standards. The effect of varying the size and shape of cells on the
flexural rigidity was studied using 15 different cellular designs. These results were then compared
to six different topology optimized beam designs, as well as three solid and hollow baseline beams.
These preliminary findings suggest that topology optimized shapes underperform their cellular
counterparts with regard to specific stiffness, and that stochastic cellular shapes deserve deeper
study.",,,,,,
"['Engelbrecht, Sarah', 'Folgar, Luis', 'Rosen, David W.', 'Schulberger, Gary', 'Williams, Jim']",2021-09-29T20:27:37Z,2021-09-29T20:27:37Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88215', 'http://dx.doi.org/10.26153/tsw/15156']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['cellular materials', 'conformal lattice structures', 'selective laser sintering', 'additive manufacturing']",Cellular Structures for Optimal Performance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99019ca1-29b7-4e85-988f-fd861b3de816/download,University of Texas at Austin,"Cellular material structures, such as honeycombs and lattice structures, enable
unprecedented stiffness and strength characteristics, for a given weight. New design and CAD
technologies to construct cellular materials are presented in this paper. Such materials have very
complex geometries, hence the need for additive manufacturing processes to produce them. A
series of experiments was performed to build and test parts fabricated using Selective Laser
Sintering. Variations in mechanical properties were quantified and related to processing
conditions. Examples help illustrate the variety of applications of cellular materials in the
aerospace, automotive, motorsports, energy, electronics, and related industries. A software tool
is being developed to enable users to design and construct parts with cellular structures.",,,,,,
"['Yang, Li', 'Miyanaji, Hadi']",2021-11-02T19:19:39Z,2021-11-02T19:19:39Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89871,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['ceramics', 'additive manufacturing', 'review', 'applications']",Ceramic Additive Manufacturing: A Review of Current Status and Challenges,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d950305-2d9b-4830-920f-98e9c6fed90f/download,University of Texas at Austin,"In recent years, various additive manufacturing (AM) technologies that are capable of
processing ceramic materials have been demonstrated. On one hand, many of the AM ceramic
technologies have demonstrated geometry freedom capability and broad range of material
flexibility. In some of the ceramic AM processes the part accuracies have also been favorably
demonstrated. On the other hand, when reviewing the requirements of ceramic structures from
applications perspective, there still appears to exist a misalignment between the demonstrated
capability of ceramic AM and the required performance. The lack of critical microstructural
characteristic and performance evaluation results are likely setting significant barriers for the
broader adoption of ceramic AM, which should be addressed via close collaborations between
academia and industries.",,,,,,
"['Weiss, C.M.', 'Aindow, M.', 'Marcus, H.']",2021-09-28T18:15:12Z,2021-09-28T18:15:12Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88142', 'http://dx.doi.org/10.26153/tsw/15083']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Selective Area Laser Deposition', 'Vapor Infiltration', 'ceramic joints', 'gas phase pulsed laser', 'laser processing']",Ceramic Joining by Gas Phase Pulsed Laser Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b5081dc2-d65b-4861-bab4-f07d1ee8be90/download,University of Texas at Austin,"The method of Selective Area Laser Deposition (SALD) and Vapor Infiltration
(SALDVI) has been successfully used to fabricate small three-dimensional SiC/SiC and
SiC/metal powder parts. Ceramic joints made by this technique have been limited by the
throwing power of the laser resulting in incomplete joint penetration. Studies were performed to
show the effectiveness of a fiber laser, with a wavelength of 1070 nm, for a joining process. The
ability of the laser to penetrate a powder bed was utilized in the joint fabrication. The
combination of powder fill, and deep laser penetration into the powder bed shows potential in the
field of ceramic joining.",,,,,,
"['Tompkins, J.V.', 'Birmingham, B.R.', 'Marcus, H.L.']",2018-11-08T15:34:09Z,2018-11-08T15:34:09Z,1995,Mechanical Engineering,doi:10.15781/T2QB9VR4K,http://hdl.handle.net/2152/69889,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Selective beam deposition', 'SALD', 'deposition']",Ceramic Joining by Selective Beam Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/52d9a51d-7506-4d61-9b1b-20454ce78477/download,,"Current methods ofjoining of ceramic components may compromise the strength, chemical
resistance, or high temperature properties of the resulting ceramic parts. A new method of
joining, Ceramic Joining by Selective Beam Deposition, creates an all-ceramic joint
between two or more ceramic components through selective decomposition of a gas
precursor. An all-ceramic joint not only preserves the valuable properties of the ceramic
materials joined, but may be tailored to match the coefficient of thermal expansion ofthe
original material(s). The added material may be the same as one or both of the joined
Inaterials, or may be a composite material. This preliminary work explores the effect of
scanning speed and precursor pressure on Selective Beam Deposition ofsilicon carbide
using tetramethylsilane.",,,,,,
"['Rafi, Abid Hasan', 'Lakusta, Marharyta', 'Anthony, Vincenzo', 'Basler, Grace', 'Grier, Sophie', 'Moeller, Lauren', 'Lipke, David', 'Watts, Jeremy Lee', 'Hilmas, Greg', 'Leu, Ming C']",2023-01-20T14:11:45Z,2023-01-20T14:11:45Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117256', 'http://dx.doi.org/10.26153/tsw/44137']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Ceramic On-Demand Extrusion', 'High-temperature Ceramic', 'Compact Heat Exchanger', 'Microchannel', 'Paste Extrusion']",Ceramic On-Demand Extrusion of ZrB2-SiC Microchannels for Ultra High-Temperature Compact Heat Exchanger,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea8ebb4b-0c06-44c6-9e84-7f6f0f65c983/download,,"Ceramic On-Demand Extrusion (CODE) is a paste extrusion based additive manufacturing 
process that has been developed for the fabrication of dense ceramic components. This paper 
presents a study of using the CODE process to build microchannels with ZrB2-SiC aqueous paste 
for the fabrication of an ultra-high-temperature compact heat exchanger (CHE). The aqueous paste 
is developed from ZrB2 and SiC (70/30 vol%) powders to possess properties suitable for the 
extrusion process. The performance and properties of the microchannels are tested for use in the 
CHE, which features a large heat transfer area to volume ratio and has potential applications in 
aero-engines, microturbines, etc., as well as high-efficiency power generation systems.",,,,,,
"['Griffith, Michelle L.', 'Chu, Tien.Min', 'Wagner, Warren', 'Halloran, John W.']",2018-10-03T19:55:01Z,2018-10-03T19:55:01Z,1995,Mechanical Engineering,doi:10.15781/T20K26W76,http://hdl.handle.net/2152/68685,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['alumina', 'SLA', 'custom-made hydroxyapatite ceramic implants']",Ceramic Stereolithography for Investment Casting and Biomedical Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c213bad-7ea0-465c-bd6e-7a5bf32c93d2/download,,"Ceramic green bodies can be created using stereolithography methods by using an
ultraviolet curable suspension of ceramic powders in place of the usual resin -a ""ceramic resin"".
Weare developing ceramic resins from hydryoxyapatite ceramics, to enable custom made ceramic
implants by SLA, and from silica and alumina, to enable metal casting molds by SLA. We
demonstrate SLA ofsilica, a model refractory for metal casting molds, and SLA of alumina, which
present the rheological behavior and UV curing properties of several ""ceramic resins"", and discuss
silica parts made on an SLA-250.",,,,,,
"['Vail, N.K.', 'Barlow, J.W.']",2018-04-19T17:17:39Z,2018-04-19T17:17:39Z,1992,Mechanical Engineering,doi:10.15781/T2TB0ZC2F,http://hdl.handle.net/2152/64387,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'SLS', 'Selective Laser Sintering', 'high-temperature']","Ceramic Structures by Selective Laser Sintering of Microencapsulated, Finely Divided Ceramic Materials",Conference paper,https://repositories.lib.utexas.edu//bitstreams/817d8b43-60ab-4939-a2e5-78888678e5ce/download,,"The feasibility of producing ceramic green parts by Selective Laser Sintering
from microencapsulated, finely divide ceramic powders has been reported in
an earlier paper. Post-processing of a silica/zirconium orthosilicate system
and an alumina system, both utilizing a polymer binder in the form of a
coating, are discussed in this paper. Ceramic green parts require postprocessing
to remove the intermediate polymer binder and to impart strength
properties to the ceramic bodies. In this paper, the use of ceramic cements
and high temperature firing to realize strengths will be discussed. The effects
of cement concentration and controlled drying rates on the strengths and
dimensional accuracy of the ceramic bodies are also discussed.",,,,,,
"['Cheverton, Mark', 'Singh, Prabhjot', 'Smith, Scott', 'Chan, Kwok Pong']",2021-10-06T22:28:12Z,2021-10-06T22:28:12Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88459', 'http://dx.doi.org/10.26153/tsw/15396']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'ceramic polymers', 'ultrasound transducers', 'piezoelectric']",Ceramic-Polymer Additive Manufacturing System for Ultrasound Transducers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a86d0a19-7fb0-447d-9dff-58ec4007c69e/download,University of Texas at Austin,"A modified multi-layer lithography process is used to additively manufacture highresolution netshape ceramic structures by photopolymerizing a ceramic-polymer slurry using
structured light patterns. This paper will discuss the development of a low-cost, high speed
manufacturing process method for the fabrication of piezoelectric ceramic transducer elements in
the 1-25 MHz frequency range. The key considerations in the development of the process
including the selection and optimization of slurry materials for the deposition of PZT 5H
materials, optical exposure parameters, debinding/sintering profiles, process monitoring, and
post manufacturing processing. Ongoing work includes improvements to the materials
properties, improved throughput and geometric fidelity.",,,,,,
"['Khoshnevis, Behrokh', 'Zhang, Jing', 'Fateri, Miranda', 'Xiao, Zichen']",2021-10-12T20:50:52Z,2021-10-12T20:50:52Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88738', 'http://dx.doi.org/10.26153/tsw/15672']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Selective Inhibition Sintering', 'sintering inhibitor', 'ceramics 3D printing']",Ceramics 3D Printing by Selective Inhibition Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c05e41b3-8a2e-46d8-aaf1-c0abbd4ffbad/download,University of Texas at Austin,"Selective Inhibition Sintering (SIS) has been proven effective in producing polymeric and
metallic parts. Due to the low cost and high quality of SIS printing, the impact of SIS printing in
the 3D printing industry could be disruptive. The potential of SIS is further extended to ceramics,
an important but hard to print material, by the same mechanism of creating an easy-to-break
sacrificial mold. Due to the high sintering temperature of ceramics, fluid based inhibitors
delivered by inkjet printing tend to not be effective in SIS for ceramics. Accordingly, the new
concept of inhibition by dry powder delivery is implemented. Preliminary experiments have
shown the feasibility and ease of printing of simple ceramic parts. Additional experiments are
underway to increase the possible part complexity and accuracy, and to optimize the sintering process.",,,,,,
"['Taylor, Robert M.', 'Manzo, Joe', 'Flansburg, Lori']",2021-11-01T20:51:12Z,2021-11-01T20:51:12Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89745,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['certification process', 'strategy', 'structural fittings', 'additive manufacturing']",Certification Strategy for Additively Manufactured Structural Fittings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/517fc9fd-d3b4-49d1-ac88-34d6910613be/download,University of Texas at Austin,"While many opportunities exist to leverage additive manufacturing technology for design
improvement, structural component fabrication with additive technologies must
demonstrate reliability and integrity sufficient to satisfy certification authorities in order to
open the door for use on flight vehicles. This certification challenge is formidable given the
large number of process parameters, the magnitude of process variability, and the sensitivity
of mechanical properties to these process variables. Historical precedent in certification of
other materials and processes, such as composites, castings, and welded joints that exhibit
sensitivity to parameters, geometry, and operator skill provides a guide to certification of
additive structures. This paper discusses certification processes for these components and
applies lessons and methods from them to develop a strategy to certify an additively
manufactured structural fitting component.",,,,,,
"['Patel, Sagar', 'Keshavarz, Mohsen', 'Vlasea, Mihaela']",2021-12-06T23:12:26Z,2021-12-06T23:12:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90711', 'http://dx.doi.org/10.26153/tsw/17630']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'selective laser melting', 'titanium', 'Ti6242', 'density', 'roughness', 'cracking']",Challenges during laser Powder Bed Fusion of a Near-Alpha Titanium Alloy - Ti-6242Si,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66e1fd99-2a39-411d-9b3d-cf168888fba7/download,University of Texas at Austin,"Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242Si) is a near-α phase titanium alloy that has a greater strength up to 565
°C compared to the workhorse Ti-6Al-4V alloy with a typical service temperature of up to 400 °C. While there
is a wealth of literature to help understand the laser powder bed fusion (LPBF) of Ti-6Al-4V, only a few
research articles about LPBF of Ti-6242Si are available in the open literature. In this work, LPBF processing
diagrams and temperature prediction models were used to investigate the impact of process parameters such as
laser power, scan speed, and beam spot radius on macroscale characteristics of the builds such as density and
surface roughness. The use of processing diagrams allowed for exploration of density ranges between
99.55-99.98 %, and surface roughness, Sa, ranges between 8-16 μm in Ti-6242Si processed by LPBF.
Cracking in Ti-6242Si manufactured by LPBF is reported for the first time. Cracking during LPBF of Ti-6242Si
was observed to strongly depend upon the predicted melting mode (conduction, transition, and keyhole) for a
given set of LPBF process parameters.",,,,,,
"['Bekker, Anne C.M.', 'Verlinden, Jouke C.', 'Galimberti, Giorgia']",2021-10-26T19:23:01Z,2021-10-26T19:23:01Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89563,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['wire + arc additive manufacturing', 'WAAM', 'sustainability', 'life cycle assessment']",Challenges in Assessing the Sustainability of Wire + Arc Additive Manufacturing for Large Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b00c74bc-6b9a-48b6-a978-7d56f4ed8075/download,University of Texas at Austin,"Additive manufacturing is known as a disruptive technology, in enabling freedom in shape and on-demand
production with little human intervention. At present, large-scale digital manufacturing means are being
developed, such as Wire & Arc Additive Manufacturing (WAAM). These could be beneficial in aerospace,
automotive and construction industries. However, while the technology is rapidly developing, little is known on
the sustainability aspects. This article explores how such environmental effects could be assessed for a novel
technology, and the production of large-scale products by means of a Life Cycle Assessment (LCA). Forerunning
results show possible gains in material usage when compared to traditional manufacturing technologies, and in
power consumption when compared to different additive manufacturing technologies. Future research will focus
benchmarking WAAM against alternative manufacturing techniques, including green sand casting and CNC
milling.",,,,,,
"['Nycz, Andrzej', 'Noakes, Mark W.', 'Richardson, Bradley', 'Messing, Andrew', 'Post, Brian', 'Paul, Jonathan', 'Flamm, Jason', 'Love, Lonnie']",2021-11-04T18:49:37Z,2021-11-04T18:49:37Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90002', 'http://dx.doi.org/10.26153/16923']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['large-scale metal parts', 'additive manufacturing excavator', 'AME', 'case study', 'challenges']",Challenges in Making Complex Metal Large-Scale Parts for Additive Manufacturing: A Case Study Based on the Additive Manufacturing Excavator,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e6aed5a2-9e44-4d90-92fe-404860a0d897/download,University of Texas at Austin,"The Additive Manufacturing Excavator (AME) contained several key components that
were 3D printed at The Manufacturing Demonstration Facility (MDF) of Oak Ridge National
Laboratory (ORNL); it was presented at and performed a live demonstration for the CONEXPO
2017 exhibition in Las Vegas, Nevada in March of 2017. This paper presents challenges in building
functional, large-scale metal parts based on a case study of the excavator. The excavator’s metal
arm was 3D printed using a modified Wolf Robotics automated metal inert gas (MIG) welding
cell. Tasks included designing a new type of slicer for the metal additive manufacturing (AM)
process, integrating the slicing software with the Wolf Robotics system, developing the deposition
process, characterizing geometric features and material properties, managing heat, designing
mechanical components for metal AM, and developing a machining approach to achieve the final
part. Two fully functional excavator arms were printed and machined. Integrated hydraulics
passageways that also served as structural stiffeners were included in the build for demonstration
purposes. As a direct result of this project, Wolf Robotics is now working towards a commercially
available large-scale metal AM system.",,,,,,
"['Chesser, Phillip', 'Post, Brian K.', 'Lind, Randall', 'Lloyd, Peter', 'Love, Lonnie J.']",2021-11-04T14:46:58Z,2021-11-04T14:46:58Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89974,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['changing print resolution', 'nozzle diameter', 'selectable nozzle', 'BAAM', 'big area additive manufacturing']",Changing Print Resolution on BAAM via Selectable Nozzles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a00b5470-718a-422d-9b09-539153b952d5/download,University of Texas at Austin,"Big Area Additive Manufacturing (BAAM) is an additive manufacturing (AM) technique
that rapidly deposits polymer to fabricate large components. However, the increase in deposition
rates leads to a decrease in resolution and a consequent decline in part surface finish. A novel
technique has been developed where the nozzle diameter can be changed mid-print using a poppet
nozzle selector. With this technique, a course resolution can be employed to rapidly fabricate the
interior of a part, while a fine resolution can be used on the surface. This allows for improved
surface quality and resolution without significantly increasing print time. This work will explain
the development of the selectable nozzle and integration with the BAAM system to produce
selective high-resolution surfaces on parts.",,,,,,
"['Cunningham, C.R.', 'Wang, J.', 'Dhokia, V.', 'Shrokani, A.', 'Newman, S.T.']",2021-11-17T23:56:35Z,2021-11-17T23:56:35Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90361', 'http://dx.doi.org/10.26153/tsw/17282']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'additive manufacturing', 'interpass temperature', '316LSi', 'directed energy deposition']",Characterisation of Austenitic 316 LSi Stainless Steel Produced by Wire Arc Additive Manufacturing with Interlayer Cooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2eb5a961-e518-4f0b-8ebf-68e4120e86e4/download,University of Texas at Austin,"Wire arc additive manufacturing (WAAM) expands the possibilities of cost effectively producing
large-scale, complex metal objects at high deposition rates. Austenitic stainless steel is a
commonly used material and has many applications in the marine and nuclear industry due to its
high toughness and corrosion resistance. Processes parameters such as heat input and interpass
temperature can greatly affect the materials properties, part functionality and the economics of
WAAM production. However, the effect of these process parameters is not well understood for
WAAM of 316LSi. In this research, the effects of the interpass temperature and heat input process
parameters on WAAM of austenitic AISI 316LSi stainless steel are experimentally analysed and
evaluated. It was found that the heat input and interpass temperature influences the
cellular/dendritic morphology and the formation of macro-scale grains within the microstructure.
Additionally, use of higher heat input, resulted in a 28.7% improvement in average Young’s
modulus compared to lower heat input, although this remained lower than provided by wrought
annealed material.",,,,,,
"['Hoye, N.P.', 'Appel, E.C.', 'Cuiuri, D.', 'Li, H.']",2021-10-07T14:55:57Z,2021-10-07T14:55:57Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88470', 'http://dx.doi.org/10.26153/tsw/15407']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['metal deposition', 'additive manufacturing', 'gas tungsten arc', 'cold wire', 'aerospace']",Characterisation of Metal Deposition During Additive Manufacturing of Ti-6Al-4V by Arc-Wire Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5410e0e9-c23e-4a5b-be29-64ad06739eb4/download,University of Texas at Austin,"This study considers the use of the gas tungsten arc (GTA) welding process in
conjunction with ‘cold’ wire addition to give layer-wise build-up of thin walled structures,
simulating those commonly found in aerospace applications, which may in the future be
manufactured by additive means. Taguchi DOE and multiple regression analysis methods have
been applied to quantitatively establish relationships between common process parameters
including arc length, arc current, travel speed and wire feed speed and resulting weld bead
geometries and actual metal deposition rates. Mathematical expressions for build-up height,
thickness and surface roughness are presented and evaluated against experimental data, with
observations related to physical phenomena.",,,,,,
"['Tang, H. H.', 'Yen, H. c.', 'Chiu, M. L.', 'Jou, J. H.']",2020-03-11T15:08:10Z,2020-03-11T15:08:10Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80246', 'http://dx.doi.org/10.26153/tsw/7265']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Ceramic Laser Fusion,The Characteristics and Applications of Ceramic Laser Fusion and Ceramic Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/89c9af32-4633-4198-9daf-6a86f88dcdbc/download,,"The aim of present study is to investigate the possible application of the ceramic parts
which are fabricated with the process of Ceramic Laser Fusion or Ceramic Laser Sintering.
The experimental results reveal: (1) CLF can lead to a reduction in the porosity of the
ceramic part but also can induce micro-cracks. Therefore, this process cannot produce a part
with the required strength by a post-process of infiltration; (2) CLS is capable of fabricating a
ceramic part with high porosity. By adjusting the slurry formulation and varying the scanning
energy, the open porosity can be over 90vol% of the total porosity. After a post-process of
infiltration, the density can be increased to 95%; therefore, CLS can apply to produce a part
with high strength. Because the high open porosity leads to a good permeability, the process
of CLS is suitable for the fabrication of ceramic shell mold.",,,,,,
"['Masuo, Christopher', 'Nycz, Anddrzej', 'Nycz, Andrzej', 'Noakes, Mark W.', 'Love, Lonnie J.']",2021-11-09T16:36:49Z,2021-11-09T16:36:49Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90108', 'http://dx.doi.org/10.26153/tsw/17029']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['build characteristics', 'geometric features', 'wire-arc additive manufacturing', 'WAAM']",Characterization and Analysis of Geometric Features for the Wire-Arc Additive Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67403813-7581-4c19-b8f3-ad613e858515/download,University of Texas at Austin,"The wire-arc additive manufacturing (AM) process expands the possibilities of effectively
producing large-scale, complex metal objects through high deposition rates at low costs. However,
this process is prone to irregularities in geometric features that occur from improper thermal
conditions and build parameters that cause uneven build heights. This paper discusses a method to
obtain consistent build characteristics and near net shape geometric features for the wire-arc AM
process. Process parameters are established for each material printed to ensure characterization of
layer build height and even flow in the interior of parts. Various sections of the build including
perimeter, infill, and various wall thicknesses require different strategies to correctly build the part.
Open-loop build geometry is still not sufficient to build a part to near net shape of the original
model. Average layer height is determined and used with adaptive height control to print the
correct, modeled height.",,,,,,
"Srinivasan, Rohit K.",2021-10-28T22:06:34Z,2021-10-28T22:06:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89713,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'sprockets', 'robotics', 'plastic sprockets', 'Chap Research']",Characterization and Testing of 3D Printed Sprockets,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fed8a4f1-8f64-4a70-abca-b0c0e3321427/download,University of Texas at Austin,"Although arguably only 30 years old, 3D printing is already having a tremendous impact upon a
broad spectrum of industries, from medical products to consumer goods and nearly every industry in
between. The primary driver for growth has been the ability to rapidly prototype components at very
low cost. However, as 3D printing technology has matured, industry participants are experimenting
with printing components for production and long-term use as opposed to just prototypes.
Chap Research has created a web-based application used to 3D print a “sprocket” – a toothed wheel
used in chain-driven systems. This paper details our study to determine the applicability of these plastic
3D printed sprockets in production and for long-term use within certain robotics applications, an area
traditionally dominated by metal (aluminum) sprockets.
The study varied a range of design parameters and evaluated whether plastic (PLA) 3D printed
sprockets could withstand the torsional stresses and fatigue failure modes present in robotics
applications (specifically for FIRST competition robots). This paper also describes two custom test
rigs that were built, one to characterize torsional stress and the other for fatigue stress analysis.
Our study indicated that, for our target application, FIRST robotics competitions, 3D printed
sprockets were quite sufficient in production and for long-term use. Layer height and infill settings for
the 3D prints had the largest impact on the performance of these sprockets. While this is not a study to
comprehensively compare performance of 3D printed sprockets to their aluminum counterparts, the big
surprise was that 3D printed sprockets performed even better than metal sprockets for fatigue stress
modes of failure. Using these results, this study also makes some recommendations on infill and layer
height settings for achieving the desired performance for FIRST robotics applications.
The study also showed the relationship between the load applied to a 3D printed sprocket and the
number of cycles of continuous operation before a fatigue load related failure occurred and makes a
conjecture on a range of load for “infinite life” of operation.
Future extensions of this study may focus on additional fatigue loading tests, expanding to broader
sets of load and printer conditions, further optimization of build parameters, varying printing materials,
and different 3D printing technologies such as SLS.",,,,,,
"['Taminger, Karen M.B.', 'Hafley, Robert A.']",2019-10-24T18:29:28Z,2019-10-24T18:29:28Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77421', 'http://dx.doi.org/10.26153/tsw/4510']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Fabrication,Characterization of 2219 Aluminum Produced by Electron Beam Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ceb76f83-7724-4aaa-a5d9-6355f853b1e9/download,,"Researchers at NASA Langley Research Center are developing a new electron beam
freeform fabrication (EB F3
) technique to fabricate metal parts. This process introduces metal
wire into a molten pool created by a focused electron beam. Potential aerospace applications for
this technology include ground-based fabrication of airframe structures and on-orbit construction
and repair of space components and structures. Processing windows for reliably producing high
quality 2219 aluminum parts using the EB F3
 technique are being defined. The effects of
translation speed, wire feed rate, and beam power on the resulting microstructures and
mechanical properties are explored. Tensile properties (ultimate tensile strength, yield strength,
and elongation) show little effect over the range of processing conditions tested. Basic
processing-microstructure-property correlations are drawn for the EB F3
 process.",,,,,,
"['Mao, Q.', 'Coutris, N.', 'Fadel, G.']",2021-10-12T22:53:01Z,2021-10-12T22:53:01Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88763', 'http://dx.doi.org/10.26153/tsw/15697']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic additive manufacturing', 'acoustic softening', 'deformation', 'aluminum 6061']",Characterization of Acoustic Softening of Aluminum 6061 Within a Plasticity Framework,Conference paper,https://repositories.lib.utexas.edu//bitstreams/489ef854-6a7c-4986-a9ff-11a7cb5942f1/download,University of Texas at Austin,"Ultrasonic additive manufacturing (UAM) is a rapid prototyping technology that features
a metal joining process through ultrasonic welding. The bonding mechanisms and mechanics of
UAM have been investigated for decades. Meanwhile, the plastic deformations of metals were
extensively studied by many researchers for their significant roles in bond formation. However,
most of these research efforts considered solely the surface frictional effects on plastic
deformation whereas the volumetric effects of ultrasound were rarely considered. This paper
investigates the effects of ultrasound on deformation of Aluminum 6061 through experimental
studies and highlights the volumetric effects of ultrasound, i.e. the “acoustic softening”: a stress
reduction on the stress-strain relation of Aluminum 6061 upon application of ultrasounds. Based
on observations obtained from a designed experimental setup, a phenomenological model is
proposed to characterize the acoustic softening effects in terms of the ultrasonic intensities.
Additionally, by modifying Hockett’s plasticity model, a plasticity frame work is established to
characterize the deformation of Aluminum 6061 in UAM. The acoustic softening model is then
incorporated into the plasticity framework. The complete model is then validated by comparing
its predictions with experimental measurements.",,,,,,
"['Brown, Ben', 'Everhart, Wes', 'Dinardo, Joe']",2021-10-20T20:26:29Z,2021-10-20T20:26:29Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89354,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['powder bed additive manufacturing', 'bulk wall', 'thin wall', 'mechanical response', 'metals', 'process parameters']",Characterization of Bulk to Thin Wall Mechanical Response Transition in Powder Bed AM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/41c4e872-7c26-482c-b544-36ef7fabd5d0/download,University of Texas at Austin,"In the development of powder bed AM process parameters, the characterization of
mechanical properties is generally performed through relatively large mechanical test
samples that represent a bulk response. This provides an accurate representation of
mechanical properties for equivalently sized or larger parts. However as feature size is
reduced, mechanical properties transition from a standard bulk response to a thin wall
response where lower power border scans and surface roughness have a larger effect. This
study identifies this threshold between bulk and thin wall for 304L SS on the Selective
Laser Melting (SLM) platform and Ti-6Al-4V on the Electron Beam Melting (EBM) platform. A possible method for improving those properties and shifting the transition from
bulk to thin wall response to smaller wall thicknesses was investigated. Mechanical testing and fractography was performed on samples to characterize the effect of wall thickness.",,,,,,
"['Whiting, J.', 'Fox, J.']",2021-10-28T14:48:14Z,2021-10-28T14:48:14Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89655,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'particle size distribution', 'powder spreading']",Characterization of Feedstock in the Powder Bed Fusion Process: Sources of Variation in Particle Size Distribution and the Factors that Influence Them,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d55943cb-27be-43aa-a9ed-975481ae13ee/download,University of Texas at Austin,"Substantial efforts have been placed on characterizing and modeling additive manufacturing
processes. The wide scope of work already done has focused on the effects of process parameters
such as laser power, hatch spacing, scan speed and strategy, and layer thickness on the final part’s
properties. However, the characteristics of the actual powder should also be considered. The
particles’ size, morphology, roughness, and chemical composition will affect the final part
properties including surface texture, density, tensile strength, and hardness. This paper will share
some of the measurement methods used at the National Institute of Standards and Technology
(NIST) to better understand metal powder for additive manufacturing. These include the
striation/separation in transportation and handling, sampling procedures, and the actual spreading
of powder in the laser powder bed fusion process. Results are presented that illustrate variations
in the particle size distribution as a function of location on the build platform, substrate/part surface
condition, and vertical position.",,,,,,
"['Sutton, Austin T.', 'Kriewall, Caitlin S.', 'Leu, Ming C.', 'Newkirk, Joseph W.']",2021-11-02T14:58:05Z,2021-11-02T14:58:05Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89819,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['heat-affected powder', '304L', 'stainless steel', 'selective laser melting', 'characterization']",Characterization of Heat-Affected Powder Generated During the Selective Laser Melting of 304L Stainless Steel Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/679bbd0c-f68f-4941-908b-8d800e2aafa2/download,University of Texas at Austin,"The selective laser melting (SLM) process is an Additive Manufacturing (AM) technique that uses
a laser to fuse successive layers of powder into near fully dense components. Due to the large
energy input from the laser during processing, vaporization and instabilities in the melt pool occur
causing the formation of condensate and laser spatter, collectively known as heat-affected powder.
Since heat-affected powder settles into the powder bed, the properties of the unconsolidated
powder may be altered compromising its reusability. In this study, characterization of 304L heat-affected powder was performed through particle size distribution measurements, x-ray diffraction,
metallography, energy-dispersive spectroscopy mapping, and visualization of grain structure with
the aid of a focused-ion beam. The results show morphological, microstructural, and surface
chemistry differences between the starting powder and heat-affected powder formed during
processing which aid in the understanding of laser spatter and condensate that form in the SLM
process.",,,,,,
"['Cormier, Denis', 'Harrysson, Ola', 'West, Harvey']",2019-11-21T18:27:13Z,2019-11-21T18:27:13Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78559', 'http://dx.doi.org/10.26153/tsw/5615']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Beam Melting,Characterization of High Alloy Steel Produced Via Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15e4089e-8303-4fbc-875d-f948b8746f03/download,,"Electron Beam Melting (EBM) is a direct-to-metal freeform fabrication technique in
which a 4 kW electron beam is used to melt metal powder in a layer-wise fashion. As this
process is relatively new, there have not yet been any independently published studies of
the high alloy steel microstructural properties. This paper describes the EBM process and
presents results of microstructural analyses on H13 tool steel processed via EBM.",,,,,,
"['Weaver, Jason', 'Jones, Jason']",2021-11-09T15:29:35Z,2021-11-09T15:29:35Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90095', 'http://dx.doi.org/10.26153/tsw/17016']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['computer numerical controlled', 'CNC milling machine', 'high deposition polymer extrusion', 'hybrid manufacturing']",Characterization of High-Deposition Polymer Extrusion in Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2f22aeb5-cc8d-4997-bf11-557a2bbbe0b3/download,University of Texas at Austin,"Hybrid manufacturing processes that include additive and subtractive operations have
unlocked many of the design limitations that were not previously available. Additive processes
allow increased design flexibility, customization, and complexity. Subtractive processes enable
higher production speeds and improved accuracy and surface finish. This paper describes a hybrid
system that combines a computer numerically controlled (CNC) milling machine with a high
deposition rate polymer extruder to create artifacts using hybrid additive/subtractive processes.
Future research plans are described, including possible applications for this system in
multimaterial and multi-process manufacturing.",,,,,,
"['Karnati, Sreekar', 'Khiabani, Atoosa', 'Flood, Aaron', 'Liou, Frank', 'Newkirk, Joseph W.']",2021-11-11T14:59:27Z,2021-11-11T14:59:27Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90210', 'http://dx.doi.org/10.26153/tsw/17131']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['impact toughness', '304L', 'stainless steel', 'laser powder bed fusion', 'additive manufacturing']",Characterization of Impact Toughness of 304L Stainless Steel Fabricated Through Laser Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/854efced-253b-4e38-aba3-c6cbab7927c4/download,University of Texas at Austin,"In this research, the impact toughness of powder bed based additively manufactured 304L
stainless steel was investigated. Charpy specimens were built in vertical, horizontal and inclined
(45°) orientations to investigate the variation in toughness with build direction. These specimens
were tested in as-built and machined conditions. A significant difference in toughness was
observed with varying build directions. The lowest toughness values were recorded when the notch
was oriented in line with the interlayer boundary. The highest toughness was recorded when the
notch was perpendicular to the interlayer boundary. A significant scatter in toughness values was
also observed. The variation and distribution among the toughness values were modeled by
performing 3-parameter Weibull fits. The performance and variation of the additively
manufactured 304L were also compared with the toughness values of wrought 304 stainless. The
additively manufactured material was observed to be significantly less tough and more variant in
comparison to wrought material.",,,,,,
"['Perez, K. Blake', 'Williams, Christopher B.']",2021-10-12T20:11:33Z,2021-10-12T20:11:33Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88730', 'http://dx.doi.org/10.26153/tsw/15664']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['extrusion-based direct write', 'PolyJet', 'material jetting', 'in-situ', 'conductive traces', 'Direct Write', 'Additive Manufacturing']",Characterization of In-Situ Conductive Paste Extrusion on PolyJet Substrates,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2308841a-a6e9-44b1-9c42-88257d5ede45/download,University of Texas at Austin,"The integration of Direct Write technologies into Additive Manufacturing system enables the
in-situ deposition of conductive traces during part printing, and thus the creation of parts with
embedded electronics. In this paper, the authors detail their research of integrating an
extrusion-based direct write system into a PolyJet material jetting system to create multimaterial products with structurally integrated, functional electronics. An investigation of the
dispensing (e.g. orifice diameter, dispense pressure, and toolhead speed), drying (e.g., time and
temperature), and substrate parameters (e.g., VeroWhitePlus and TangoBlackPlus) on the
geometry of the deposited trace is presented. Additionally, the adhesive compatibility of the
conductive material on both rigid and elastomeric PolyJet substrate surfaces is investigated by
measuring wet and dry contact angles.",,,,,,
"['Pappas, John M.', 'Dong, Xiangyang']",2021-11-18T02:02:37Z,2021-11-18T02:02:37Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90406', 'http://dx.doi.org/10.26153/tsw/17327']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['transparent ceramics', 'magnesium aluminate spinel', 'laser direct deposition', 'additive manufacturing']",Characterization of Laser Direct Deposited Magnesium Aluminate Spinel Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/73d3fbf4-b26c-4794-8b40-fe24ca96c526/download,University of Texas at Austin,"An additive manufacturing (AM) approach, via laser direct deposition, is investigated in printing
transparent magnesium aluminate spinel (MAS) ceramics. Using AM, traditionally difficult or
expensive to manufacture shapes, such as optical lenses, can be rapidly manufactured to near net
shape, reducing time consuming and expensive post processing requirements. The transparency of
MAS ceramics is highly dependent on the microstructure, with porosity and microcracking having
the largest effect on the transparency of fabricated parts. With high localized heat inherent in the
laser deposition process, the microstructure of ceramic parts can be controlled by adjusting
processing parameters. In this study, thin wall MAS structures were fabricated by varying
processing parameters. Processing parameters including laser scan speed and laser power had a
large influence on the part quality. To fabricate transparent magnesium aluminate spinel ceramics
with high mechanical properties, the effects of processing parameters on part porosity, density,
and microstructure were studied. Dense MAS parts were successfully fabricated through the laser
direct deposition process. Low scan speed and high laser power showed the most promising results
in fabricating MAS parts of low porosity. Using a low powder flow rates of 0.58 g/min, a relative
density of nearly 98% was achieved. Directional cooling through the substrate and from the
powder conveying gas led to columnar grain growth at a tilt angle from the build direction. The
primary defects of fabricated MAS ceramics were found to be residual porosity and microcracking,
which negatively affected part transparency and mechanical properties. Typical microcracking
patterns included transverse and longitudinal cracking, with longitudinal cracks being more
prevalent due to the existence of columnar grains and intergranular fracture mode. A preliminary
study demonstrated that a certain degree of transparency was achieved in additively manufactured
MAS ceramic parts via laser direct deposition.",,,,,,
"['Basak, Amrita', 'Das, Suman']",2021-11-02T14:11:52Z,2021-11-02T14:11:52Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89809,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['nickel-base superally', 'MAR-M247', 'additive manufacturing', 'scanning laser epitaxy', 'SLE', 'microstructure', 'Vickers microhardness', 'residual stress']",Characterization of MAR-M247 Deposits Fabricated Through Scanning Laser Epitaxy (SLE),Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd71d8c3-e3c5-4efb-a72b-07d448a131f9/download,University of Texas at Austin,"This paper aims to characterize the microhardness and the process-induced residual stress in
nickel-base superalloy MAR-M247 fabricated using a laser-powder bed fusion (LPBF)-based
additive manufacturing (AM) process, scanning laser epitaxy (SLE). The SLE fabricated MAR-M247 samples are investigated using optical microscopy, scanning electron microscopy, x-ray
diffraction, and Vickers microhardness measurements. The results show that the average Vickers
microhardness values do not show any significant variation with changes in SLE processing
parameters. However, the microhardness values are unevenly distributed and show variations
along the build direction and the laser movement direction. Overall the hardness values are within
±2 limits for all the SLE deposited MAR-M247 samples. The effect of heat treatment on the
microhardness and the residual stress is also investigated. The results show that the microhardness
increases and the residual stress decreases after the heat treatment.","This work is sponsored by the
Office of Naval Research through grant N00014-14-1-0658.",,,,,
"['Martin, Julie P.', 'Kander, Ronald G.']",2019-09-20T18:18:34Z,2019-09-20T18:18:34Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75924', 'http://dx.doi.org/10.26153/tsw/3023']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Alloyed,Characterization of Mechanically Alloyed Polymer Blends for Selective Laser Sintering 92,Conference paper,https://repositories.lib.utexas.edu//bitstreams/312214db-2f70-4871-9184-d32a536cd053/download,,"Cryogenic mechanical alloying (CMA) is presented in this work as an effective technique for creating materials for selective laser sintering (SLS) applications. CMA offers a solid state method for creating micro-composites consisting of finely dispersed phases, which can then be selectively laser sintered into parts containing co-continuous phases. Particle size and shape, microstructure, and melting characteristics of mechanically alloyed particles are discussed in terms of applications to the SLS process. The
characteristics of several model polymer blend systems are investigated using scanning electron microscopy, light scattering particle size analysis, and differential scanning calorimetry. Although only polymer/polymer blend particles are studied here, the CMA process is also a viable technique for creating SLS powders using ceramics or metals.",,,,,,
"['Vu, Ivan', 'Bass, Lindsey', 'Meisel, Nicholas']",2021-10-21T15:19:57Z,2021-10-21T15:19:57Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89393,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['PolyJet', 'additive manufacturing', 'multi-material fabrication', 'acrylic layers', 'fabrication interface']",Characterization of Multi-Material Interfaces in PolyJet Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8c95f275-4e1c-4ddc-a012-733d0fe0dcb7/download,University of Texas at Austin,"Relatively few engineering devices and structures are monolithic, as combinations of
materials are often needed to obtain the necessary functionality, performance, weight, and cost
requirements. Progress in additive manufacturing now allows multiple materials and even
blends of materials to be produced in a single manufacturing process, opening new opportunities
for expeditiously achieving functional and performance targets. Just as interactions at interfaces
have long been of interest in the area of adhesive bonding, similar issues need to be addressed for
printed composite materials. In this study, a Stratasys PolyJet system was used to produce
configurations consisting of a soft acrylic layers (TangoBlackPlus) sandwiched by two stiffer
acrylic strips (VeroWhitePlus). Several test methods based on the double cantilever beam
specimen, a common experimental approach to characterize adhesive performance, were
evaluated to characterize the fracture resistance of the assembled layers. Failures nominally
occurred at the interface between the two types of materials. Further testing is providing insights
into the effects of print direction, postcuring, and interface architecture on the resulting fracture
energies. These studies suggest the opportunities for designing printed interfaces with improved
performance and durability for multi-material additive manufacturing products.",,,,,,
"['Obielodan, John', 'Vergenz, Kevin', 'Aqil, Danyal', 'Wu, Joseph', 'Ellistrem, Laurel Mc']",2021-11-18T02:24:29Z,2021-11-18T02:24:29Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90414', 'http://dx.doi.org/10.26153/tsw/17335']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['PLA', 'lignin', 'biocomposites', '3D printing', 'sustainability']",Characterization of PLA/Lignin Biocomposites for 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91a7a0c3-6876-415e-a8a0-61b7e42fdff7/download,University of Texas at Austin,"A greater proportion of polymer-based three-dimensional (3D) printing materials are
synthetic petroleum derivatives that are not biodegradable, contributing to environmental
pollution and have potential adverse effects on human health. Polylactic acid (PLA) is currently
the most widely used among the bio-based alternatives. This work explores alternative
environmentally friendly bio-based polymers sourced from sustainable crop and forest biomass
derivatives for 3D printing. Various blends of PLA/Organosolv lignin were extruded for fused
filament fabrication (FFF) 3D printing process. The processing parameters and results of
mechanical and thermal properties of fabricated test specimens of the biocomposite with up to
40wt% lignin concentration are presented. Results indicates that lignin, a low-cost waste product
of pulping for the paper industry and bioethanol fuel production could serve as a key component
of new biocomposite polymers for 3D printing applications.",,,,,,
"['Schmidt, J.', 'Dechet, M.A.', 'Gómez Bonilla, J.S.', 'Hesse, N.', 'Bück, A.', 'Peukert, W.']",2021-11-18T01:28:14Z,2021-11-18T01:28:14Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90393', 'http://dx.doi.org/10.26153/tsw/17314']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['powder characterization', 'polymer powders', 'selective laser sintering']",Characterization of Polymer Powders for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/694a86c2-ebd2-46b3-91dd-c4230ce6c7e6/download,University of Texas at Austin,"Flowability and packing properties are essential for powder spreading and resulting part properties in
powder bed fusion processes (PBF), such as selective laser sintering (SLS). In this contribution, powder
requirements for SLS, structure-property relationships and appropriate methods for powder characterization are
reviewed. Effects of particle size, particle shape and surface functionalization on flowability, packing density
and tribo-charging will be discussed for commercial PA12 laser sintering powders (virgin vs. aged), polyolefin
and polyester powders. The possibilities of dry particle coating as an efficient method to tailor powder
flowability, bulk density and charging behavior are demonstrated. The capabilities of a Schulze ring shear
tester, a powder tensile strength tester, a thermally controllable ring shear apparatus and a model experiment
mimicking the powder spreading are discussed to assess SLS processability.",,,,,,
"['Bhat, V.V.', 'Geetha, K.', 'Das, R.N.', 'Gurumoorthy, B.', 'Umarji, A.M.']",2019-09-18T16:50:56Z,2019-09-18T16:50:56Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75902', 'http://dx.doi.org/10.26153/tsw/3002']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Alumina,Characterization of Polyolefin – Alumina compounded mix for FDC processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf000f96-90fe-4071-b585-3719ffe8c943/download,,"Fused deposition of ceramics (FDC) uses thermoplastic binder and ceramic blend as
feed material. The geometry of the fused deposition machine restricts the workability of the
FDC feed material, which is in the form of a filament. The feasibility of the usage of these
filaments is mainly based on the viscosity at the working temperature and the compressive
modulus of the feed material at near room temperature. The polymers based on Polyethylene
(PE), having two molecular weights 3,000 (LDWAX) and 341,000 (LDPE) were mixed in
various weight proportions by solvent method using toluene as solvent, to develop a binder
system for Fused Deposition Modeling of alumina. Variation of viscosity as a function of
composition, temperature and solid loading was measured using spindle viscometer and
capillary rheometer. Dilatometric thermal expansion of 50 Vol% alumina compounded
binders is measured up to 120°C. The pronounced softening of the compounded mixture is
observed beyond 70°C, when the volume % of LDWAX is in excess of 50% total binder
content. The compression strength decreases from 720 N to 310 N for pellet having 1.2cm
diameter and 1.5 aspect ratio, when the percentage of LDWAX varies from 40 to 70% in the
binder composition. The suitability of the compounded mix of LDWAX and LDPE binder
with 40 Vol. % alumina for FDC is being evaluated in a StratasysTM1600 machine.",,,,,,
"['Gornet, T.J.', 'Davis, K.R.', 'Starr, T.L.', 'Mulloy, K.M.']",2019-10-25T16:07:18Z,2019-10-25T16:07:18Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77442', 'http://dx.doi.org/10.26153/tsw/4531']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Laser Sintering,Characterization of Selective Laser Sintering™ Materials to Determine Process Stability,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e2aca76a-6a16-4e21-9e92-f835aad687e3/download,,"The Selective Laser Sintering (SLS) process has proved to be an excellent method for
prototyping functional parts out of engineering thermoplastics such as polyamides. However, the
material undergoes physical and chemical changes due to repeated heating cycles in the SLS
equipment. This causes variations in powder characteristics and performance in the SLS process.
With the increased utilization of SLS for direct manufacturing it is necessary to develop a
characterization and testing system that can determine powder fitness to ensure process stability
and part quality. Current powder recycling methodologies use an average virgin-to-used powder
mixture. In a new approach, a testing mechanism to deliver a numerical, measurable material
characterization will be discussed. Experimental results of repeated reuse of material and its
resulting physical effects on mechanical properties, shrinkage, and chemical tests will be
presented. A definitive testing and measurement process control will be shown to improve
process stability and thus part quality and consistency.",,,,,,
"['Kambly, Kiran', 'Yuan, Dajun', 'Shao, Peng', 'Das, Suman']",2021-09-28T19:06:03Z,2021-09-28T19:06:03Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88156', 'http://dx.doi.org/10.26153/tsw/15097']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Large Area Maskless Photopolymerization', 'polymerization shrinkage', 'polymerization stresses', 'ceramic molds']",Characterization of Shrinkage and Stresses in Large Area Maskless Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/45440075-7fec-4ff5-9262-011db5946b63/download,University of Texas at Austin,"Large Area Maskless Photopolymerization (LAMP) is a high throughput direct digital
manufacturing technology being developed for producing ceramic investment casting molds.
Polymerization shrinkage and accompanying stresses developed during photopolymerization of
ceramic particle-loaded resins in LAMP can cause deviations from the desired geometry. The
extent of deviations depends on photoinitiator concentration, filler loading, degree of monomer
conversion and operating parameters such as energy dose. An understanding of shrinkage and
stresses built up in the part can assist in developing source geometry compensation algorithms
and exposure strategies to alleviate these effects. Real-time Fourier Transform Infrared
Spectroscopy (RTFTIR) operated in Attenuated Total Reflectance (ATR) mode is used to
characterize the three-dimensional shrinkage stresses. This work is sponsored by DARPA Grant
HR0011-08-1-0075.",,,,,,
"['Mei, H.', 'Valant, M.', 'Hu, D.', 'Kovacevic, R.']",2019-10-24T18:20:03Z,2019-10-24T18:20:03Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77417', 'http://dx.doi.org/10.26153/tsw/4506']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Powder Feeder,The Characterization of the Performance of a New Powder Feeder for Laser Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d5d91adf-8a0c-47ea-80f3-b27976669aed/download,,"Laser-based additive manufacturing (LBAM) requires precise control over the metal,
ceramic, or carbide powder added to the molten pool. The feeding rate of the powder must
be very consistent, and it must respond rapidly to commands to change the feeding rate.
LBAM also requires feeding rates as low as one gram per minute. Currently, commercially
available powder feeders are optimized for such tasks as feeding powder to thermal
spraying processes, which generally require a much higher feeding rate than LBAM, and
can usually tolerate much more variation in the feeding rate. These powder feeders are
therefore not suitable for the LBAM process. The Research Center for Advanced
Manufacturing at Southern Methodist University has designed and built a new powder
feeder capable of consistent, repeatable powder delivery at extremely small flow rates. The
powder feeder is regulated by a weight-based control system, which provides real-time
measurement of the mass remaining in the feeder as powder is transferred to the powder
nozzles. The powder feeder has been fully characterized to obtain correlations between the
input parameters, powder type and the resulting mass flow rates. The powder nozzles at the
laser head have also been characterized. The nozzle angle, standoff height, and carrier gas
flow rate have each been optimized experimentally to maximize the concentration of
powder arriving at the molten pool created by the laser beam, as detected using a sheet of
He-Ne laser light and a coaxial vision system. The powder delivery efficiency of the
system has been thus maximized, increasing both the deposition rate and the quality of the
deposited material.","This work was financially supported by THECB, Grants 003613-0022-1999 and 03613-
0016-2001, NSF, Grants No. DM1-9732848 and DM1-9809198, and the U.S. Department
of Education, Grant No. P200A80806-98.",,,,,
"['Cormier, Denis', 'West, Harvey', 'Harrysson, Ola', 'Knowlson, Kyle']",2020-02-14T15:28:40Z,2020-02-14T15:28:40Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79985', 'http://dx.doi.org/10.26153/tsw/7010']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Electron Beam Melting,Characterization of Thin Walled Ti-6Al-4V Components Reduced via Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2a943c0a-34ee-4ca2-84a5-8972863f6764/download,,"Direct-metal energy beam SFF processes typically produce layers by scanning the
contours and then filling in the area within the contour. Process parameters used to solidify
contours are often different from those for fill areas. It is to be expected, therefore, that the
contour and fill area regions will have different microstructures. This can have important
ramifications for thin walled components such as biomedical implants whose slices have very
little fill area. This paper characterizes the metallurgical differences in contour and fill areas in
titanium components produced via Electron Beam Melting. The implications of these properties
for thin walled components are described.",,,,,,
"['Linn, John', 'Weaver, Jason M.', 'Miles, Michael P.', 'Hovanski, Yuri']",2021-11-10T22:44:59Z,2021-11-10T22:44:59Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90197', 'http://dx.doi.org/10.26153/tsw/17118']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['strength property', 'interfacial bonds', 'interface', 'hybrid manuufacturing', 'metal additive manufacturing']",Characterizing Interfacial Bonds in Hybrid Metal AM Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e470ae43-3637-4808-b9f3-f32a6456c913/download,University of Texas at Austin,"The capabilities of various metal Additive Manufacturing (AM) processes, such as
Powder Bed Fusion - Laser (PBF-L) are increasing such that it is becoming ever more common
to use them in industrial applications. The ability to print atop a substrate broadens that scope of
applications. There is ongoing research regarding the mechanical properties of additively
processed materials, but not much regarding the interaction between additive material and its
substrate. An understanding of the mechanical and performance properties of the AM/substrate
interface is imperative. This paper describes a study of the strength properties of AM/substrate
interfaces, with respect to torsion and tension, and compares them to their fully wrought and
fully additive counterparts.",,,,,,
"['Mattingly, Frye L.', 'Franc, Alan', 'Kunc, Vlastimil', 'Duty, Chad']",2021-12-01T23:38:42Z,2021-12-01T23:38:42Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90659', 'http://dx.doi.org/10.26153/tsw/17578']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['internal porosity', 'fiber reinforced materials', '3D printing', 'big area additive manufacturing', 'BAAM']",Characterizing Internal Porosity of 3D-Printed Fiber Reinforced Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6ed67dc-8a25-4159-808b-e8d18911d55f/download,University of Texas at Austin,"As the functional requirements for 3D printed parts become more demanding, the use of fiber
reinforced materials in material extrusion printers is increasingly common. Although fiber-reinforced thermoplastics offer higher stiffness and strength, the internal volume of the extruded
material often has a high degree of porosity which can negatively impact mechanical properties.
This research surveys the internal porosity present across a range of material extrusion additive
manufacturing platforms, primarily those involving a single screw extruder, such as the Big Area
Additive Manufacturing (BAAM) system. The porosity within the volume of an extruded bead
was quantified through image analysis of cross sectional micrographs. The impact of extrusion
rate, transient vs steady state flow, multiple hardware configurations, and material conditions were
evaluated. Across the five systems studied porosities ranged from 0.1% to 18.4% with the greatest
reductions in porosity coming from two systems that added a vent to the extruder barrel which
lowered porosity 64% in one case and 98% in the other.",,,,,,
"['Sudbury, Zeke', 'Duty, Chad', 'Kunc, Vlastimil', 'Kishore, Vidya', 'Ajinjeru, Christine', 'Failla, Jordan', 'Lindahl, John']",2021-10-27T21:50:18Z,2021-10-27T21:50:18Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89627,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['functionally graded materials', 'large scale additive manufacturing', 'additive manufacturing', 'optimization']",Characterizing Material Transition for Functionally Graded Material Using Big Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ddd453d1-f898-4bbb-8b9d-afc7521b782c/download,University of Texas at Austin,"This study examines functionally graded materials (FGM) on a polymer based large scale
additive manufacturing system. FGM utilizes a less expensive material with sub-optimal
mechanical properties for the majority of the part, and uses more expensive higher performance
material in selected areas. This process aims to optimize cost with weight and mechanical
performance. FGM is already used a variety of industries, but is not common place in additive
manufacturing, specifically large scale additive manufacturing like Cincinnati Incorporated’s Big
Area Additive Manufacturing (BAAM). BAAM can use a variety of plastic injection molding
and extrusion style polymer pellets, which allows it to use both commodity materials and high
performance engineering polymers. This study is an initial assessment of FGM using glass fiber
reinforced ABS and carbon fiber reinforced ABS, and characterizes the performance of a density
gradient shape function to characterize the blending of materials.",,,,,,
"['Ziegelmeier, Stefan', 'Wöllecke, Frank', 'Tuck, Christopher', 'Goodridge, Ruth']",2021-10-07T18:49:25Z,2021-10-07T18:49:25Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88503', 'http://dx.doi.org/10.26153/tsw/15437']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'polyurethane', 'powders', 'laser sintering', 'flow properties', 'bulk behaviour']",Characterizing the Bulk & Flow Behaviour of LS Polymer Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/12e26f4c-fc5a-45d1-b44f-4c33a3b742e9/download,University of Texas at Austin,"The properties of laser sintering (LS) powders affect processability and the quality of parts
manufactured. This study compared three different methods used to quantify both the static
and dynamic powder properties – a Revolution Powder Analyzer, FT-4 Powder Rheometer
and Hausner Ratio. The aim of the work was to identify the most reliable method to
characterize powder properties in correlation to the dynamic conditions that occur during LS.
The experiments focused on different particle size distributions of a cryogenically ground
polyurethane powder compared to a standard polyamide 12 LS material, PA2200. The results
have led to a deeper understanding regarding powder interactions and therefore serve as input
for material design and quality assurance.",,,,,,
"['Brackett, James', 'Cauthen, Dakota', 'Condon, Justin', 'Smith, Tyler', 'Gallego, Nidia', 'Kunc, Vlastamil']",2021-11-18T01:25:23Z,2021-11-18T01:25:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90392', 'http://dx.doi.org/10.26153/tsw/17313']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['print parameters', 'volumetric porosity', 'mechanical performance', 'density', 'extrusion deposition additive manufacturing']",Characterizing the Influence of Print Parameters on Porosity and Resulting Density,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c61433d3-ae61-448e-9a34-9f1b01b33495/download,University of Texas at Austin,"Extrusion deposition additive manufacturing produces parts with inherent porosity, which
typically manifests as easily accessible voids between beads. This open porosity can also be
accompanied by voids within the beads themselves, and both types can impact a part’s desired
performance. Porosity is influenced by a variety of factors, including infill percentage, layer
height, nozzle diameter, print speed, and raster orientation. While their influence on mechanical
properties and porosity have been studied previously, there has been minimal work connecting
print parameters to porosity and subsequently to mechanical performance. This study
investigates the relationships between print parameters, volumetric porosity, and mechanical
performance. In addition, this study measures both open and closed porosity through use of a
helium pycnometer rather than image analysis of a cross-section. Thus, this study will identify
correlations between the volumetric density of parts and the resulting mechanical performance as
a function of print parameters.",,,,,,
"['Brackett, James', 'Hussein, Zaky', 'Charles, Elijah', 'Smith, Tyler', 'Hassen, Ahmed', 'Kim, Seokpum', 'Kunc, Vlastimil', 'Duty, Chad']",2021-12-06T21:40:47Z,2021-12-06T21:40:47Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90681', 'http://dx.doi.org/10.26153/tsw/17600']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['internal structure', 'transition regions', 'characterization', 'CF-ABS', 'big area additive manufacturing']",Characterizing the Internal Morphology of Transition Regions in Large-Scale Extrusion Deposition Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/92528331-aadb-42b8-b5ed-fa54cfa156c0/download,University of Texas at Austin,"A dual-hopper feed system that was developed for the Big Area Additive Manufacturing
(BAAM) system allows for transitioning between different materials while maintaining continuous
deposition. This technique creates a step-change in material feedstock by switching the pellet
feeding system to alternate which hopper is currently supplying material, allowing for multi-material construction. The step-change in feedstock material produces a transition region that is
characterized by a compositional gradient and blended internal morphology. Initial cross-sectional
imaging of the transition region revealed a non-homogenous blend of materials with distinct
domains of each material, likely due to incomplete mixing within the screw. This study used a
carbon fiber reinforced acrylonitrile butadiene styrene (CF-ABS) and an unfilled ABS to
characterize the internal structure and to correlate it to mechanical performance by tracking
microhardness across cross-sections of the transition region.",,,,,,
"['Corum, Tyler', 'O’Connell, Johnna', 'Brackett, James', 'Spencer, Ryan', 'Hassen, Ahmed', 'Duty, Chad']",2023-02-10T17:51:42Z,2023-02-10T17:51:42Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117457', 'http://dx.doi.org/10.26153/tsw/44338']",eng,2022 International Solid Freeform Fabrication Symposium,Open,polymer,Characterizing the Thermal-Induced Distortion of Large-Scale Polymer Composite Printed Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85b1f5ca-7b14-455b-a908-5983fc74216e/download,,"The Big Area Additive Manufacturing (BAAM) system has been used to print large-scale 
parts, such as automotive structures and molds for tooling, with fiber-reinforced polymer 
composites. Incorporating reinforcing fibers in printed parts is commonly used to increase 
stiffness and strength, but it also introduces significant anisotropy in the thermomechanical 
performance, which can lead to distortion and warping during thermal cycling. Characterizing and 
understanding how a printed tool distorts is crucial to maintaining tolerances and avoiding part 
failure. This study uses digital image correlation (DIC) to measure the coefficient of thermal 
expansion (CTE) of a printed part from room temperature and to a known steady state temperature. 
The samples were printed with carbon fiber reinforced acrylonitrile butadiene styrene (CF-ABS). 
Various nozzle geometries were evaluated in this study with the intent of minimizing the thermal-
induced distortion experienced by printed parts.",,,,,,
"['Corum, Tyler', ""O'Connell, Johnna"", 'Heres, Maximilian', 'Foote, Jeff', 'Duty, Chad']",2024-03-27T03:39:58Z,2024-03-27T03:39:58Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124471', 'https://doi.org/10.26153/tsw/51079']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['large-format additive manufacturing', 'LOCI-One', 'thermomechanics']",CHARACTERIZING THERMOMECHANICAL PROPERTIES OF LARGE-FORMAT PRINTED COMPOSITE POLYMER STRUCTURES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/87225841-2356-4230-a038-79f36e980450/download,University of Texas at Austin,"Large-format additive manufacturing (LFAM) is a manufacturing technique where a high
volume of material is extruded in a layer-by-layer fashion to form structures that typically measure
several meters in scale. The LOCI-One system is an LFAM-type system operated by Loci
Robotics, Inc. that features a high throughput extruder mounted on a 6-axis robot arm. This
research used the LOCI-One system to print single bead walls of 20% by weight carbon fiber
reinforced acrylonitrile butadiene styrene (CF-ABS) at various layer deposition methods, print
speed, layer times, and bead widths. The coefficient of thermal expansion (CTE) of the printed
structures was measured to quantify effects of print conditions on thermomechanical performance.
The CTE of the LFAM printed walls was measured using a large-scale digital image correlation
system to characterize the distortion of the fiber reinforced composite material in the x- (print
direction) and z- (between layers) directions. This study determined that with varying print
parameters the CTE measured in the x-direction was largely influenced by bead geometry with the
CTE measured in the z-direction relatively unaffected by either the varying parameters or the
method in which layer deposition occurred.",,,,,,
"['Bai, Di', 'Patil, Vineeth R.', 'Esterman, Marcos', 'Chang, Shu']",2021-10-13T20:11:27Z,2021-10-13T20:11:27Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88775', 'http://dx.doi.org/10.26153/tsw/15709']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['unconsolidated powders', 'electrophotographic printing toner', 'three-dimensional microstructures', 'additive manufacturing']",Characterizing Three Dimensional Microstructures Formed by Particles: An Example of Electrophotographic Printing Toner,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43498dfa-ab17-464e-a1f2-abdbbf87d5dd/download,University of Texas at Austin,"Additive manufacturing of objects using powders can result in microscopic structures based on the
properties of particles used. In additive manufacturing, piles of powder are consolidated by one or other
mechanisms in order to form a part. The resulting microstructure within the part can impact its engineering
performance. Predicting and controlling the engineering performance requires the characterization of the
part’s material interior microstructures. H owever, obtaining the microstructure is difficult since the
interior of a powder is a challenge to visualize.
In this paper, unconsolidated powders are characterized. We have used Confocal Laser Scanning
Microscopy to image three-dimensionally sediments of micron-sized poly-dispersed electro-photographic
printing particles. Using image analysis tools, we have extracted each particle’s position and radius in
selected sampling volumes. Through this methodology, we demonstrate the possibility to recreate the
three-dimensional particle structures and extract values for morphological parameters for powder systems.
The feasibility of direct and quantitative particle structural characterization can lead to much needed
methods and tools to relate particle structures to the process of fabrication, the design of materials, and
product performance in additive manufacturing.",,,,,,
"['Barroi, A.', 'Hermsdorf, J.', 'Kling, R.']",2021-10-04T21:05:49Z,2021-10-04T21:05:49Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88346', 'http://dx.doi.org/10.26153/tsw/15285']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['GMA cladding', 'additive manufacturing', 'laser deposition']",Cladding and Additive Layer Manufacturing with a Laser Supported Arc Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3cab5849-e3b4-48ac-93a8-9c34d440849f/download,University of Texas at Austin,"This paper describes the potential of a new process, combining the geometrical
precision of a laser technique and the deposition rates of GMA cladding. Dilutions as low
as 3 % can be achieved, leading to a high purity, in the first layer. Different material
combinations like mild steel with X45CrSi9-3 are presented. Microsections for
penetration depth determination show the high quality of the deposition layers. A
hardness of the coatings of 63 HRC is reached. Hardfacing of shafts serve as an
application example. The low heat input enables the process to build up structures. This
results in a process variant for additive layer manufacturing which is also presented. The
production of macro-sized structures is shown and discussed.",,,,,,
"['Mischliwski, S.', 'András, D.', 'Weigold, M.']",2023-04-05T13:39:09Z,2023-04-05T13:39:09Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117772', 'http://dx.doi.org/10.26153/tsw/44651']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['flexible clamping concept', '6-side machining', 'hybrid manufacturing']",Clamping Concept for 6 Side Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/55480564-5136-46e8-8590-739fc81d25a4/download,,"For most technical applications, the surface quality and tolerances that result directly from additive 
processes are not suitable. Hybrid manufacturing as a combination of additive and subtractive manufacturing 
process steps can help solving this issue. In this work, a conceptional adjustable cast clamping process is 
introduced for a combination of Laser-based Powder-Bed-Fusion (LPBF) and milling. For component clamping 
during the milling process, the components are cast in place with a low-melting metal alloy, creating form-fit and 
force-fit connection. To prove the applicability, a rough estimation of occurring milling forces was conducted. In 
a subsequent series of tests, validation of clamping force was carried out using complex part geometries. A 
prototype fixture designed for this cast clamping process has been developed and tested. This fixture allows 
complex non-restricted 6-side machining of parts without moving it relative to the fixture or the need of any 
additional manual rework on part surfaces.",,,,,,
"['Shafer, C.S.', 'Siddel, D.H.', 'Merriman, A.L.', 'Elliott, A.M.']",2021-10-28T19:38:05Z,2021-10-28T19:38:05Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89679,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'cleated print surface', 'build platform']",Cleated Print Surface for Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e39704a0-3d3b-4b6f-9592-8f118c6b6cb0/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) has become popular among Additive Manufacturing
technologies due to its low cost, speed, and geometric scalability; however, the primitive nature
of the FDM build surface fundamentally limits the utility of FDM in terms of reliability,
autonomy, and material selection. Currently, FDM relies on adhesive forces between the first
layer of a print and the build surface; depending on the materials involved, this adhesive bond
may or may not be reliable. Thermal contraction between the build plate and build materials can
break that bond, which causes warpage and delamination of the part from the build surface and
subsequent failure of the part. Furthermore, with each print, the user must use tools or special
maneuvering to separate the printed part from the build surface as well as retexture or replace the
used build surface. In this paper we present a novel build platform that allows for a mechanical
bond between the print and build surface by using dovetail-shaped features. The first layer of the
print flows into the features and becomes mechanically captivated by the build platform. Once
the print is completed, the platform is rolled or flexed open to release the part from the
mechanical bond. This design not only lowers the risk of delamination during printing but also
eliminates the need for a user to reset or replace the build surface between print jobs. The
effectiveness of each geometry was determined by measuring the distance at the pinch point
compared to the distance that the extrusion filled below the pinch point. The Captivation Ratio
was measured to compare the different geometries tested and determine which direction of
extrusion creates a better ratio.",,,,,,
"['Kirschman, Jill S.', 'Kirschman, Charles F.', 'Fadel, Georges M.', 'Greenstein, Joel S.']",2018-12-06T22:09:45Z,2018-12-06T22:09:45Z,1997,Mechanical Engineering,doi:10.15781/T2DN40G3K,http://hdl.handle.net/2152/71435,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'CAD']",The Clemson Intelligent Design Environment For Stereolithography-Cides 2.0,Conference paper,https://repositories.lib.utexas.edu//bitstreams/55770349-4ef7-4a75-b17a-cfb5bdcbc9fa/download,,"There are a large number of commercial Rapid Prototyping (RP) devices available today. All
ofthese machines begin with a Computer-Aided Design (CAD) model, which is tessellated,
sliced and then built layer-by-Iayer on the RP device. All ofthese operations, except the actual
building ofthe part, are completed on a computer. Therefore, many improvements to the RP
processes can be achieved through software, without affecting the RP devices or the warranties
on them. This has led to the development of a front-end software product to support the task of
preparing the part to be built. The Clemson Intelligent Design Environment for
Stereolithography (CIDES) is a user-centered interface between the CAD system and RP
systems, primarily the Stereolithography Apparatus (SLA).
CIDES 2.0 is designed to provide a variety oftools which are valuable to the users ofRP
systems, including the ability to view and modify tessellated (STL) files, generate supports, and
slice STL files into layer (SLI) files for use on an SLA. It also provides the ability to view SLI
and merged (V) files. Furthermore, CIDES offers additional translation capabilities that make it
valuable for other RP processes. The package has proven useful in the Laboratory to Advance
Industrial Prototyping (LAIP) at Clemson University. CIDES 2.0 is a new X Windows-based
release based on the original version ofCIDES with many additional features. A new HumanComputer
Interface is the major improvement to this release.",,,,,,
"['Rogers, Bill', 'Gitter, Andrew', 'Bosker, Gordon', 'Faustini, Mario', 'Lokhande, Mahendra', 'Crawford, Richard']",2019-10-18T16:40:30Z,2019-10-18T16:40:30Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76256', 'http://dx.doi.org/10.26153/tsw/3345']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Prosthetic,Clinical Evaluation of Prosthetic Sockets Manufactured by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b98de382-bf7e-44e3-9c03-2695bef67306/download,,"A pilot study was undertaken to evaluate the clinical acceptance of prosthetic limb sockets
manufactured using solid freeform fabrication (SFF). The fabrication of sockets for amputees is a
natural application for SFF. The socket is the part of the prosthetic limb that fits onto the
amputee’s residual limb. Each socket is custom manufactured for each individual amputee. Four
amputees were successfully fit with sockets created using selective laser sintering. The scope of
the study included software development, finite element analysis, materials testing, and clinical
evaluation. This paper discusses socket design issues and clinical testing results.",,,,,,
"['Hu, D.', 'Mei, H.', 'Tao, G.', 'Kovacevic, R.']",2019-10-09T16:24:43Z,2019-10-09T16:24:43Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76156', 'http://dx.doi.org/10.26153/tsw/3245']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Cladding,Closed Loop Control of 3D Laser Cladding Based on Infrared Sensing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/473bfd2b-6cd9-46b3-b178-68a2dc5fcd8c/download,,"In this paper, a heat input closed-loop control system based on infrared image sensing for 3D
laser cladding is introduced. A high frame-rate (up to 800 frames/s) camera is installed coaxially
on the top of the laser-nozzle setup. Complete of the infrared images of the molten pool can be
acquired with a short nozzle-substrate distance in different scanning directions, eliminating the
noise from the metal powder. The characteristics of the images show a clear relationship with the
parameter variations of the cladding process. A closed-loop control system is built based on the
feedback of the infrared image sensing. The control results show a great improvement in the
geometrical accuracy of the part being built","This work was financially supported by THECB, Grant 003613-0022-1999, NSF, Grants
No. DM1-9732848 and DM1-9809198, and the U.S. Department of Education, Grant No.
P200A80806-98.",,,,,
"['Hartman, Aja', 'Zhao, Zhao']",2023-01-27T17:41:55Z,2023-01-27T17:41:55Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117343', 'http://dx.doi.org/10.26153/tsw/44224']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Closed Loop Control Utilizing In-situ Pattern Printing and Reading for Quality Level Determination in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/65605e8f-9d92-4ff2-9f50-4ce299debab8/download,,"HP’s Multi Jet Fusion (MJF) is a powder-based technology that selectively melts 
polymer powder, using a fusing agent, in a layer-by-layer fashion to create 3D parts. One of 
the challenges for wide adoption of additive manufacturing is the assurance of the print process 
and part consistency through a cost-effective and non-destructive fashion. Non-destructive part 
quality measurements can be achieved through a method of printing two-dimensional patterns 
at desired locations throughout the part. The readability of these patterns provides either the 
signals to actuate process changes during the print or information on part quality during and 
after printing. This method can also be used for covert part marking to provide design 
intellectual property security.",,,,,,
"['Thompson, N.R.', 'Weaver, J.M.']",2023-03-30T16:23:25Z,2023-03-30T16:23:25Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117703', 'http://dx.doi.org/10.26153/tsw/44582']",eng,2022 International Solid Freeform Fabrication Symposium,Open,PETG,Closed Loop Recycling of PETG in Fused Granule Fabrication Large Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ff8c5b9-c258-458e-bea2-d372d41414fb/download,,"Plastic waste is a critical worldwide problem that impacts additive manufacturing (AM). 
Extensive research has explored how plastic waste in AM can be reduced by recycling prints into 
new filament, with varying success. An alternative to filament-based extrusion is “fused granule 
fabrication” (FGF), which extrudes from pellets or granules. This method is often used for large 
area additive manufacturing (LAAM) of polymers. This paper expands upon the knowledge base 
from previous research on LAAM and examines the extent to which PETG can be recycled and 
reprinted through the same FGF tool without significant loss to its material properties. The metric 
used for comparing material properties is tensile testing along the direction of deposition. Recycled 
material was granulized, filtered, and dehydrated. This resulted in effective printing of 100% 
recycled PETG, with recycled samples demonstrating 83% of the tensile strength of virgin PETG.",,,,,,
"['Cholewa, S.', 'Jaksch, A.', 'Drummer, D.']",2023-03-29T14:49:01Z,2023-03-29T14:49:01Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117675', 'http://dx.doi.org/10.26153/tsw/44554']",eng,2022 International Solid Freeform Fabrication Symposium,Open,PBF-LB/P,Coalescence Behavior of Polyamide 12 as Function of Zero-Shear Viscosity and Influence on Mechanical Performance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4763654-ac9f-4dc2-b788-9da23bcc0575/download,,"The favored material for powder bed fusion of polymers (PBF-LB/P) is polyamide-12. Its molecular weight 
increases from post-condensation at elevated temperatures in the building chamber, consequently having different 
properties when reused. An important aspect of PBF directly affected hereby is the coalescence behavior, as it 
significantly determines the surface quality, porosity, and thus the component’s mechanical properties. However, 
detailed studies on coalescence are limited to virgin powders with low viscosity; therefore, coalescence behavior 
of polyamide-12 with different molecular weights is investigated using hot stage microscopy. Additionally, the 
zero-shear viscosity is determined using the Carreau model, allowing comparison of experimental results to 
sintering models. Furthermore, the mechanical properties and surface qualities are analyzed, and components with 
adequate values are made with two-cycle reprocessed powder. Since surface flaws do not exist uniformly across 
all components, the orange peel effect is not attributed solely to the increased viscosity of the reused powder.",,,,,,
"['Liu, Zhien', 'Suppakarn, N.', 'Cawley, James D.']",2019-03-17T13:39:50Z,2019-03-17T13:39:50Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73698', 'http://dx.doi.org/10.26153/tsw/840']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['CAM-LEM', 'solid freeform']",Coated Feedstock for Fabrication of Ceramic Parts by CAM-LEM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e4ba2d9-2e3e-4274-9afb-0976c75fc044/download,,"In laminated object manufacturing of ceramic components, lamination is one of the most
important materials issues. Good lamination ensures monolithic component after firing.
Otherwise, lamination defects that inevitably will occur in the parts will affect the
properties of ceramic components. Adhesive (both liquid and non-liquid) lamination
processes were developed for the cut-then-stack (CAM-LEM) procedure. The non-liquid
adhesive lamination is discussed in detail.",,,,,,
"['Ming, Ling Wai', 'Gibson, Ian']",2019-09-23T15:44:44Z,2019-09-23T15:44:44Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75942', 'http://dx.doi.org/10.26153/tsw/3041']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Colour Rapid Prototyping Based on SLS Process 227,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e109bfec-ecab-40e7-a341-aad916f9d002/download,,"Currently, the colour of parts made by the Selective Laser Sintering (SLS) process depends on the colour of the material used. SLS cannot make multiple coloured prototypes because only homogeneous powder (or powder composites) can be used during the process. In this paper, an ink-jet based mechanism is designed to print multiple colours onto the prototypes. The surface tension of conventional ink used in bubble jet printers is so high that it cannot penetrate into the SLS powders. To reduce the surface tension, ethanol is added to it. The ratio of ink to ethanol for necessary penetration is determined by experiments. This paper will go on to describe how the ink affects the structure of SLS materials. The effect of temperature on the penetration of ink into powders will also be discussed.",,,,,,
"['Budde, L.', 'Merkel, P.', 'Prasanthan, V.', 'Bährisch, S.', 'Faqiri, M.Y.', 'Lammers, M.', 'Stonis, M.', 'Hermsdorf, J.', 'Hassel, T.', 'Uhe, J.', 'Behrens, B.-A.', 'Breidenstein, B.', 'Overmeyer, L.']",2023-04-03T15:43:50Z,2023-04-03T15:43:50Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117719', 'http://dx.doi.org/10.26153/tsw/44598']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser hot-wire cladding', 'Cladding', 'Hot forming', 'Residual stress', 'Microstructure', 'Hardness', 'Tailored  Forming']",Combination of Cladding Processes with Subsequent Hot Forming as a New Approach for the Production of Hybrid Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd9341c6-07be-4640-9c51-e23870b877b6/download,,"A new process chain for the manufacturing of load-adapted hybrid components is presented. The ""Tailored 
Forming” process chain consists of a deposition welding process, hot forming, machining and an optional heat 
treatment. This paper focuses on the combination of laser hot-wire cladding with subsequent hot forming to 
produce hybrid components. The applicability is investigated for different material combinations and component 
geometries, e.g. a shaft with a bearing seat or a bevel gear. Austenitic stainless steel AISI 316L and martensitic 
valve steel AISI HNV3 are used as cladding materials, mild steel AISI 1022M and case hardening steel AISI 5120 
are used as base materials. The resulting component properties after laser hot-wire cladding and hot forming such 
as hardness, microstructure and residual stress state are presented. In the cladding and the heat-affected zone, the 
hot forming process causes a transformation from a welding microstructure to a fine-grained forming 
microstructure. Hot forming significantly affects the residual stress state in the cladding the resulting residual 
stress state depends on the material combination.",,,,,,
"Boudreaux, J.C.",2020-02-17T14:25:29Z,2020-02-17T14:25:29Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79997', 'http://dx.doi.org/10.26153/tsw/7022']",eng,2004 International Solid Freeform Fabrication Symposium,Open,planar slices,A Combinatorial Parametric Engineering Model for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77cf7fe6-4b32-4959-a4a4-291fdd560c5a/download,,"Fabricated parts are often represented as compact connected smooth 3-manifolds with
boundary, where the boundaries consist of compact smooth 2-manifolds. This class of mathematical
structures includes topological spaces with enclosed voids and tunnels. Useful information about these
structures are coded into level functions (Morse functions) which map points in the 3-manifold onto their
height above a fixed plane. By definition, Morse functions are smooth functions, all of whose critical
points are nondegenerate. This information is presented by the Reeb graph construction that develops a
topologically informative skeleton of the manifold whose nodes are the critical points of the Morse function
and whose edges are associated with the connected components between critical slices. This approach
accurately captures the SFF process: using a solid geometric model of the part, defining surface
boundaries; selecting a part orientation; forming planar slices, decomposing the solid into a sequence of
thin cross-sectional polyhedral layers; and then fabricating the part by producing the polyhedra by additive
manufacturing. This note will define a qualitative and combinatorial parametric engineering model of the
SFF part design process. The objects under study will be abstract simplicial complexes K with boundary
∂K. Systems of labeled 2-surfaces in K, called slices, will be associated with the cross-sectional polyhedral
layers. The labeled slices are mapped into a family of digraph automata, which, unlike cellular automata,
are defined not on regular lattices with simple connectivities (cells usually have either 4 or 8 cell
neighborhoods) but on unrestricted digraphs whose connectivities are irregular and more complicated.",,,,,,
"['Baumers, M.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Rosamond, E.', 'Hague, R.']",2021-10-06T22:42:17Z,2021-10-06T22:42:17Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88464', 'http://dx.doi.org/10.26153/tsw/15401']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'estimator', 'direct metal laser sintering', 'build-time', 'energy consumption', 'production cost']","Combined Build-Time, Energy Consumption and Cost Estimation for Direct Metal Laser Sintering",Conference paper,https://repositories.lib.utexas.edu//bitstreams/312734ab-e18e-4ac0-acf5-501201223068/download,University of Texas at Austin,"As a single-step process, Additive Manufacturing (AM) affords full measurability
with respect to process energy inputs and production cost. However, the parallel character of
AM (allowing the contemporaneous production of multiple parts) poses a number of problems
for the estimation of resource consumption. A novel combined estimator of build-time, energy
consumption and production cost is presented for the EOSINT M270 Direct Metal Laser
Sintering system. It is demonstrated that the quantity and variety of parts demanded and the
resulting ability to utilize the available machine capacity impact process efficiency, both in
energy and in financial terms.",,,,,,
"['Johnson, Blake', 'Allcorn, Eric', 'Baek, Min G.', 'Koo, Joseph H.']",2021-10-05T13:56:33Z,2021-10-05T13:56:33Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88373', 'http://dx.doi.org/10.26153/tsw/15312']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['polyamide 11', 'nanocomposites', 'fire retardant', 'selective laser sintering', 'montmorillonite', 'carbon nanofiber']","Combined Effects of Montmorillonite Clay, Carbon Nanofiber, and Fire Retardant on Mechanical and Flammability Properties of Polyamide 11 Nanocomposites",Conference paper,https://repositories.lib.utexas.edu//bitstreams/1154978e-0206-4357-8b2f-97f233fa509a/download,University of Texas at Austin,"This paper is focused on the development of polyamide 11 (PA11) nanocomposites with
enhanced fire retardant (FR) properties for application in selective laser sintering (SLS). Test
specimens of PA11 containing various percentages of intumescent FR additive, montmorillonite
(MMT) clay, and carbon nanofiber (CNF) were prepared via the twin screw extrusion technique.
The combined effects of MMT clay, CNF, FR additives on the mechanical and flammability
properties of these PA11 nanocomposites are studied. Izod impact testing, tensile testing, and
SEM analysis of are used to characterize mechanical properties. UL-94 and SEM analysis of
char surfaces are used to characterize the flammability properties of these materials. Results are
analyzed to determine any synergistic effects among the additives to the material properties of
PA11.",,,,,,
"['Snyder, Jessica', 'Wang, Chengyang', 'Hamid, Qudus', 'Sun, Wei']",2021-10-05T14:36:31Z,2021-10-05T14:36:31Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88381', 'http://dx.doi.org/10.26153/tsw/15320']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'cell-laden microfluidic device', 'SFF patterning', 'replica molding', 'polydimethylsiloxane']",Combined SFF Patterning and Replica Molding for Microfabrication of Cell-Laden Microfluidic Device,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2aace3ed-7ec9-4b5e-8983-b3d0734c97eb/download,University of Texas at Austin,"We report on a novel technique using additive manufacturing to fabricate a cell-laden
polydimethylsiloxane (PDMS) microfluidic device by SFF processes and replica molding. We
demonstrate concept feasibility and present results using single and multiple layer patterns. 3-dimensional
channel architecture is achieved by CAD/CAM technology and tuning manufacturing process parameters.
Our microfluidic device is fabricated in two stages (1) print negative mold by thermal extrusion of
polycaprolactone (PCL) using layer-by-layer precision extrusion deposition then (2) casting PDMS. Cells
and matrix are selectively assembled inside microchannels using multi-nozzle printing to demonstrate
feasibility of chip as a culture environment. The objective of this work is to fabricate a cell-laden
microfluidic device by combined solid freeform patterning and replica molding with direct cell writing
into channels. This work has application as a 3D physiological model for in vitro pharmacokinetic study
in space environment in preparation for long term manned missions.",,,,,,
"['Perez, K. Blake', 'Williams, Christopher B.']",2021-10-12T18:44:40Z,2021-10-12T18:44:40Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88716', 'http://dx.doi.org/10.26153/tsw/15650']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['direct write', 'Additive Manufacturing', 'conductive materials', 'manual material patterning', 'hybrid material patterning', 'native material patterning']",Combining Additive Manufacturing and Direct Write for Integrated Electronics – A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ec1601d3-ff71-4c08-9cf6-f620ffdfd1fa/download,University of Texas at Austin,"Direct write (DW) of conductive materials in the context of Additive Manufacturing (AM)
enables embedded electronics within fabricated parts. Previous works use manual, hybrid, and
native material patterning systems to deposit conductive materials in parts fabricated by different
AM technologies. This capability could eliminate cabled interconnects and redundant electronics
packaging, resulting in a significant reduction of mass and assembly complexity. In this paper, the
authors explore applications of DW of conductive traces in the context of AM, review prior work
in the integration, and analyze the technical roadblocks facing their hybridization. Barriers to
integrating the two technology classes include material, process, and post-process compatibilities.",,,,,,
"['Ariadi, Y.', 'Campbell, R.I.', 'Evans, M.A.', 'Graham, I.J.']",2021-10-05T18:54:47Z,2021-10-05T18:54:47Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88407', 'http://dx.doi.org/10.26153/tsw/15346']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Computer Aided Consumer Design', 'Additive Manufacturing', 'consumers', 'easy-to-use design tools']",Combining Additive Manufacturing with Computer Aided Consumer Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8cba56f-e05c-43d2-888a-e865e77a7eb3/download,University of Texas at Austin,"This paper reports an investigation into the potential for consumers designing and
manufacturing their own products using a combination of “Computer Aided Consumer Design”
(CaCODE) and Additive Manufacturing (AM). Recent developments in the field of AM (cheaper
machines and new materials) have led to renewed interest in the manufacture of customised
products and, more specifically, allowing consumers to create their own bespoke products.
However, a persistent weak link in this paradigm is the inability of most consumers to create 3D
models as an input for AM. Operating a conventional CAD system requires a lengthy period of
specialist training and is therefore not viable in this context. Consequently, easy-to-use 3D
design tools are needed to make AM more accessible to consumers. This research study
investigated the suitability of such a system for enabling consumers to design their own pens for
manufacture using AM. The investigation also explored the consumer acceptance of current AM
capabilities when used for the production of consumer products. The results showed that careful
attention must be paid to the specific needs of consumers, both in terms of their product
preferences and their ability to use software. These will be used to guide the design of future
CaCODE systems.",,,,,,
"['Deckers, T.', 'Wolf, F.', 'Foret, P.', 'Witt, G.', 'Kleszczynski, S.']",2024-03-26T20:35:04Z,2024-03-26T20:35:04Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124399', 'https://doi.org/10.26153/tsw/51007']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['process monitoring', 'highspeed monitoring', 'thermal highspeed monitoring', 'process gas', 'helium', 'alloy 718']",Comparative Analysis of Process Stability in PBF-LB/M: (Thermal) Highspeed Imaging vs. Melt Pool Monitoring using Novel Gas Mixtures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6a313098-efef-4826-9dcf-b5b8f7e8bf53/download,University of Texas at Austin,"Powder bed fusion of metals using a laser beam (PBF-LB/M) is increasingly gaining
popularity in the industry. However, ensuring a consistent quality of parts processed by PBF-LB/M
is crucial to compete with established manufacturing processes. In-situ process monitoring
systems, such as coaxial melt pool monitoring (MPM), can contribute to this goal by minimizing
post-process quality control. Three monitoring systems, a commercially available MPM system,
an optical high-speed camera, and a thermal high-speed camera, were compared to identify process
phenomena. Secondly, the suitability of the MPM system for in-situ quality control was tested by
employing novel gas mixtures in the process. The mixtures include argon (Ar) with hydrogen (H2),
helium (He), and carbon dioxide (CO2). The first results showed the capabilities of the MPM
system to monitor relevant process anomalies. Also, the addition of He and H2 to the process gas
resulted in an improvement in the melt pool stability and a reduction of process by-products
compared to Ar.",,,,,,
"['Karasoglu, M.', 'Yasa, E.', 'Tan, E.', 'Yağmur, A.']",2021-12-06T23:05:57Z,2021-12-06T23:05:57Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90709', 'http://dx.doi.org/10.26153/tsw/17628']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'L-PBF', 'electron powder bed fusion', 'E-PBF', 'heat treatment', 'microstructure']",A Comparative and Experimental Study on the Effect of Heat Treatment Cycles for PBF Ti6Al4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee8c896f-f414-47c4-91e2-3f9feeb94617/download,University of Texas at Austin,"Powder bed fusion (PBF) presents the highest level of technological maturity and
industrialization level for metallic materials among other Additive Manufacturing technologies.
The advantages of high geometrical complexity, ability to produce internal cavities, reduced lead
time and buy-to-fly ratio enables a wide range of application areas from aerospace to biomedical.
Laser-PBF and Electron-PBF present different limitations and opportunities while they can both
build from Ti6Al4V powder. The performance of the E-PBF and L-PBF parts highly depends on
the resulting microstructures and differs significantly due to various mechanisms such as
preheating temperatures and processing environment. Moreover, the obtained material properties
generally necessitate heat treatments for reducing residual stresses, enhancing mechanical
properties and changing the microstructure. This study aims to investigate the effect of the same
heat treatment cycles on the E-PBF and L-PBF microstructure evolution and microhardness by a
comparative experimental work with several combinations of exposure durations, temperatures
and cooling rates.",,,,,,
"['Previtali, B.', 'Demir, A.G.', 'Bucconi, M.', 'Crosato, A.', 'Penasa, M.']",2021-11-08T23:22:06Z,2021-11-08T23:22:06Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90073', 'http://dx.doi.org/10.26153/tsw/16994']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['economic feasibility', 'manufacturing costs', 'selective laser melting', 'tube-forming tools', 'tube bending']",Comparative Costs of Additive Manufacturing vs. Machining: The Case Study of the Production of Forming Dies for Tube Bending,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b75df0a0-ce21-486f-915f-fc795bd7b1b1/download,University of Texas at Austin,"Additive manufacturing processes for metallic components become economically viable
when they substitute conventional processes that make use of moulds and dies to produce casting
or semi-finished parts with high added value. Common examples are: i) components in aerospace
or energy sectors obtained by investment casting in high-temperature alloys; ii) personalized
prostheses and implants in biocompatible metals in the biomedical sector. In both cases, the annual
batch size is low and often limited to a single or few pieces. However, for many other sectors
decision making for process substitution from conventional to AM processes requires a correct
economic analysis. The cost of AM processes depends also on the use of technological advantages.
The paper explores the economic feasibility of selective laser melting (SLM) process when
producing tube-forming tools. The analysed industrial case addresses the whole annual production
of bending tools, traditionally made by milling from a solid block. The aim of this work is to
identify the levers of the process that make additive production advantageous, even in more
traditional sectors like tooling when different tool materials are used (namely a tool steel and a
bronze alloy) and when hybrid manufacturing (subtractive plus additive) is carried out.",,,,,,
"['Telenko, Cassandra', 'Seepersad, Carolyn Conner']",2021-10-04T20:20:55Z,2021-10-04T20:20:55Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88337', 'http://dx.doi.org/10.26153/tsw/15276']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'selective laser sintering', 'injection molding', 'nylon parts', 'energy consumption']",A Comparative Evaluation of Energy Consumption of Selective Laser Sintering and Injection Molding of Nylon Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a262688a-d650-41ad-94b0-2196eb237b55/download,University of Texas at Austin,"Additive manufacturing is often advocated as a sustainable alternative to competing
manufacturing technologies. This research study focuses on estimating and comparing the
energy consumption required for different production volumes of nylon parts using either
selective laser sintering (SLS) or injection molding (IM). For IM & SLS, energy consumption is
estimated for nylon material refinement and part fabrication. For IM, energy consumption is also
estimated for manufacturing the injection molds and refining their metal feedstock. A paintball
gun handle serves as a representative part for calculating and normalizing material flows and
processing times. For different sets of assumptions, cross-over production volumes are
calculated, at which the per-part energy consumption of the two processes is equivalent. These
energy-based cross-over production volumes are compared to similar economic cross-over
production volumes available in the literature.",,,,,,
"['Aremu, A.O.', 'Maskery, I.', 'Tuck, C.', 'Ashcroft, I.A.', 'Wildman, R.D.', 'Hague, R.I.M.']",2021-10-18T22:28:07Z,2021-10-18T22:28:07Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89271,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'cubic unit cells', 'metal lattice structures']",A Comparative Finite Element Study of Cubic Unit Cells for Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b37e57f-c046-47b6-a4b4-8c17d988b3a1/download,University of Texas at Austin,"Selective laser melting (SLM) enables the utilization of complicated lattice structures
in metallic components. To exploit this capability, it is important to understand the structural properties of these lattices. Topological variations in lattices are diverse, however,
only a few are suitable for SLM since some lattices require supports during manufacture
while others self-support. Difficulties associated with the removal of these supports and
their detrimental effects on surface finish makes the latter group better suited for SLM.
In this work, we investigate the structural properties of some self-supporting unit cells
via a finite element study and show that the performance of a lattice structure is largely
dependent on the topology of the unit cell. Variants of the gyroid and face centred cubic
unit cells performed better than body centred cubic cells. This was also observed when
lattices, made of repeating unit cells were compared.",,,,,,
"['Nouri, H.', 'Khoshnevis, B.']",2021-11-11T15:35:37Z,2021-11-11T15:35:37Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90222', 'http://dx.doi.org/10.26153/tsw/17143']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['sintering methods', '3D printing', 'selective separation shaping', 'SSS', 'polymer']",A Comparative Investigation of Sintering Methods for Polymer 3D Printing Using Selective Separation Shaping (SSS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/5d205e19-4025-442d-8ce8-0c247c2e0fc0/download,University of Texas at Austin,"Selective Separating Shaping (SSS) is a novel additive manufacturing process which is capable of
processing polymeric, metallic, ceramic and cementitious materials. In earlier experiments, the capabilities of
SSS in fabrication of metallic, ceramic, cement-based and polymeric parts have been demonstrated. The focus of
this research has been on exploration of sintering methods in SSS for successful fabrication of polymeric parts.
The SSS machine has been used to build specimens made of polyamide (PA6) material. Bonds between layers
under two different thermal sintering methods are investigated to achieve better control over shrinkage and
maintain effective binding between layers. ImageJ platform and binary surface plots have been used for image
processing and evaluating final porosity under each heating mechanism. Further investigations are carried out on
properties of the base materials and the choice of sintering mechanism to further improve resolution of final parts.",,,,,,
"['Kaill, N.', 'Campbell, R.I.', 'Pradel, P.', 'Bingham, G.A.']",2021-11-30T19:27:50Z,2021-11-30T19:27:50Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90521', 'http://dx.doi.org/10.26153/tsw/17440']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['material extrusion', '3-axis', '5-axis', 'anisotropic behavior', 'compressive loading', 'additive manufacturing']",A Comparative Study Between 3-Axis and 5-Axis Additively Manufactured Samples and their Ability to Resist Compressive Loading,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb248f9c-3845-4fad-9be7-1957550ffa9b/download,University of Texas at Austin,"One of the main limitations of parts made with Material Extrusion (ME) is their
anisotropic mechanical behaviour. This behaviour limits the functionality of these components
in multi-directional loading conditions. A critical factor for this mechanical behaviour is the
poor bonding between layers. 5-axis ME has the capability to orientate the printed layers in
order to limit the effect of poor inter-laminar bonding. Previous studies have investigated 5-
axis ME, but not fully explored 5-axis capabilities of this manufacturing technique. To address
this gap, this paper compares the mechanical behaviour of 3-axis and 5-axis ME samples when
subjected to compressive loading. The results demonstrate how depositing material in “3D
layers” can improve the consistency of a sample’s mechanical behaviour. This study indicates
that 5-axis ME can enable more isotropic behaviour in printed samples.",,,,,,
"['Shanmugam, Ragavanantham', 'Chandran, Jishu', 'Vinayagam, Mohanavel', 'Fakron, Osama', 'Dennison, Seth', 'Romine, Seth']",2023-02-10T14:04:31Z,2023-02-10T14:04:31Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117449', 'http://dx.doi.org/10.26153/tsw/44330']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Direct energy deposition (DED)', 'AlSi12 alloy', 'Pressure die casting', 'ultimate tensile strength', 'hardness', 'building directions']",Comparative Study of Mechanical Properties of Aluminum Alloy A356 (Al-12Si) Fabricated by Directed Energy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0afe4fa9-8da4-422a-ae9e-faaf67c2e145/download,,"Additive Manufacturing technology is rapidly gaining traction in many manufacturing 
applications due to its process parameters control and wide range of applications. There are 
other AM technologies accessible, however Direct energy deposition (DED) is a critical 
approach in metal matrix additive manufacturing. The significant two mechanical properties 
tensile strength and hardness of additively created Al-12Si Aluminum alloy by DED process 
and pressure die casted Al-12Si components are compared in this study. The strength and 
modulus of the DED and PDC manufactured components were identical if the load direction 
in the UTM machine was the same as the construction directions, however other mechanical 
parameters differed slightly. Mechanical qualities of fabricated products made from reused 
powders were also comparable to those made from unused powder.",,,,,,
"['Baumers, M.', 'Tuck, C.', 'Hague, R.', 'Ashcroft, I.', 'Wildman, R.']",2021-09-30T14:33:05Z,2021-09-30T14:33:05Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88257', 'http://dx.doi.org/10.26153/tsw/15198']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['metallic Additive Manufacturing', 'selective laser melting', 'electron beam melting', 'electricity consumption', 'process efficiency']",A Comparative Study of Metallic Additive Manufacturing Power Consumption,Conference paper,https://repositories.lib.utexas.edu//bitstreams/94e9d739-bf06-4d58-a1c3-2755b00101b3/download,University of Texas at Austin,"Efficient resource utilisation is seen as one of the advantages of Additive
Manufacturing (AM). This paper presents a comparative assessment of electricity
consumption of two major metallic AM processes, selective laser melting and electron beam
melting. The experiments performed for this study are based on the production of a common
power monitoring geometry. Due to the technology’s parallel nature, the degree of build
volume utilization will affect any power consumption metric. Therefore, this work explores
energy consumption on the basis of whole builds - while compensating for discrepancies in
packing efficiency. This provides insight not only into absolute levels of power consumption
but also on comparative process efficiency.",,,,,,
"['Nezhadfar, P.D.', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2021-12-06T22:14:51Z,2021-12-06T22:14:51Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90694', 'http://dx.doi.org/10.26153/tsw/17613']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder directed energy deposition', 'LP-DED', 'laser powder bed fusion', 'L-PBF', 'stainless steel', 'microstructure', 'texture']",A Comparative Study on the Microstructure and Texture Evolution of L-PBF and LP-DED 17-4 PH Stainless Steel during Heat Treatment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f07a342-a034-4276-9f7b-0d3d21e66740/download,University of Texas at Austin,"This study aims to characterize the microstructure and crystallographic texture of 17-4
PH stainless steel (SS) manufactured with laser powder directed energy deposition (LP-DED)
and laser powder bed fusion (L-PBF), in both non-heat treated and heat treated conditions. It is
found that the non-heat treated LP-DED 17-4 PH SS possesses coarse columnar ferrite grains
decorated with Widmanstätten ferrite grains, whereas the L-PBF counterpart has very fine and
mostly equiaxed ferrite grains along with lath martensite. An identical stress relief (SR)
temperature is obtained for both the L-PBF and LP-DED 17-4 PH SS samples based on the
phase diagrams generated using Thermo-Calc. software. The SR step prior to CA-H1025 heat
treatment resulted in texture weakening and slightly refined the grain structure. The non-heat
treated L-PBF 17-4 PH SS sample possesses strong cube and γ-fiber textures, while the texture
transfers to weaker γ-fiber components after performing SR-CA-H1025 heat treatment.",,,,,,
"['Park, Sang-in', 'Rosen, David W.', 'Duty, Chad E.']",2021-10-19T15:19:45Z,2021-10-19T15:19:45Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89296,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['electron beam melting', 'lattice structures', 'lattice structure strength']",Comparing Mechanical and Geometrical Properties of Lattice Structure Fabricated Using Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a1a05be3-a385-4163-b10c-6fff15b63c73/download,University of Texas at Austin,"To design lattice structure, a uniform voxel based approach is widely used which divides
a part into unit volumes (e.g., cubes) and maps lattice topology into those volumes. In contrast,
conformal lattice structures represent a second design method for constructing lattices in which
unit cells are constructed parallel to the surface to be reinforced and are deformed in a manner
that enables them to conform to the surface. In this paper, the strength of lattice structures
designed using these two methods (uniform voxel based and conformal) are compared based on
additive manufacturing (AM) process effects. For this purpose, spheres filled with three types of
lattice structure are fabricated using electron beam melting technology and tested in compression.
Effects of AM processes are studied in two ways – volumetric and structural performance
equivalence. Struts in lattice structures are observed through a microscope to examine volume-equivalence and tests are simulated numerically and compared to identify structural equivalence.",,,,,,
"['Fulcher, Benjamin A.', 'Leigh, David K.', 'Watt, Trevor J.']",2021-10-12T22:46:58Z,2021-10-12T22:46:58Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88761', 'http://dx.doi.org/10.26153/tsw/15695']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Direct Metal Laser Sintering', 'aluminum alloys', 'AlSi10Mg', 'Al 6061', 'coefficient of thermal expansion']",Comparison of AlSi10Mg and Al 6061 Processed through DMLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d01d125d-ebe1-4cab-91c1-d1e084bf0bd5/download,University of Texas at Austin,"Direct Metal Laser Sintering (DMLS) processing of aluminum alloys has been primarily
limited to a casting grade of aluminum, AlSi10Mg. The reasons for the choice of AlSi10Mg by
machine manufacturers are presently unknown; however, it is suspected that the reduced
coefficient of thermal expansion (CTE) due to the presence of Silicon may enhance DMLS
processability. Aluminum 6061 (Al 6061) is a commonly used alloy across a wide range of
industries and applications, and Harvest has observed a high interest in DMLS-manufactured
Al 6061 products. However, the higher CTE value potentially presents greater challenges in
controlling the shrinkage-induced warp common during DMLS. The work presented in this
paper was performed in an effort to understand differences in manufacturability as well as
mechanical properties of DMLS-processed AlSi10Mg and Al 6061.",,,,,,
"['Snelling, Dean', 'Williams, Christopher', 'Druschitz, Alan']",2021-10-12T21:23:57Z,2021-10-12T21:23:57Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88743', 'http://dx.doi.org/10.26153/tsw/15677']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', 'sand molds', 'binder burnout', 'tensile strength', '3D printing']",A Comparison of Binder Burnout and Mechanical Characteristics of Printed and Chemically Bonded Sand Molds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8a66a255-7746-4041-955c-ae0338c7929e/download,University of Texas at Austin,"Various material systems have been created for Binder Jetting of sand molds; however, a
formal analysis comparing the materials to commonly used foundry molding materials has not
been conducted. In this paper the authors investigate potential differences in the material
properties from four different commercially available binders systems for chemically bonded
sand molds. Specifically, the authors compared the binder burnout characteristics and the tensile
strength of sand created by 3D printing and conventional chemically bonded molding materials.
Increased binder content can strengthen the mold but have adverse effect on part quality.
Understanding the binder characteristics of printed molds are essential due to the potential
defects from large amounts of gas generated from binder while pouring molten metal.",,,,,,
"['Hecker, F.', 'Driediger, C.', 'Hirsch, A.', 'Moritzer, E.']",2021-12-01T23:35:48Z,2021-12-01T23:35:48Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90658', 'http://dx.doi.org/10.26153/tsw/17577']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['arburg plastic freeforming', 'fused deposition modeling', 'economic efficiency', 'process', 'comparison']",Comparison of Component Properties and Economic Efficiency of the Arburg Plastic Freeforming and Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4380083-3ea0-4be0-a148-a74fb0c32468/download,University of Texas at Austin,"The additive manufacturing process Fused Deposition Modeling (FDM) is established
in the industry for many years. A new, similar process to FDM is the Arburg Plastic
Freeforming (APF). The main differences between both processes are the form of the starting
material (FDM: Filaments, APF: Conventional granulate) and the material deposition during
the layer formation (FDM: Melt strand, APF: fine molten droplets).
Since the two processes can be used in similar applications, the aim of this study is to
compare both processes in a holistic way. Furthermore, the advantages and disadvantages of
the processes are to be highlighted. The systematic comparison between a Stratasys 400mc and
the Freeformer 200-3X is divided into the areas of component properties, design limitations and
economic efficiency. The material ABS-M30 (Stratasys) is used in both processes. The results
show comparable component properties regarding mechanical and optical properties but also
differences in design limitations and cost efficiency.",,,,,,
"['Taghipour, Ehsan', 'Leu, Ming C.', 'Guo, Nannan']",2021-10-05T18:51:14Z,2021-10-05T18:51:14Z,8/18/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88406', 'http://dx.doi.org/10.26153/tsw/15345']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['bipolar plates', 'graphite-carbon-polymer composite compression molding', 'Selective Laser Sintering']",Comparison of Compression Molding and Selective Laser Sintering Processes in the Development of Composite Bipolar Plates for Proton Exchange Membrane Fuel Cells,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf4c0f55-6b4e-4f13-8dda-a0193c8bcded/download,University of Texas at Austin,"Bipolar plates are key components of Proton Exchange Membrane (PEM) fuel cells. They carry
current away from the cell and withstand the clamping force of the stack assembly. Therefore,
PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical
strength, in addition to being light weight and low cost in terms of both applicable materials and
production methods. In order to attain these goals, we have manufactured graphite-carbon-polymer composite plates using Compression Molding (CM), which is suitable for mass
production, and Selective Laser Sintering (SLS), which is suitable for making prototypes. In this
paper, the electrical conductivity and flexural strength of the bipolar plates fabricated using the
CM process versus constitutive materials are experimentally studied. The properties of bipolar
plates fabricated using the CM process are compared with those of plates fabricated using the
SLS process. Natural graphite (NG), synthetic graphite (SG), carbon black (CB), and carbon
fiber (CF) are used as the constitutive materials for both processes, with epoxy resin employed as
the binder matrix. By varying the volume fraction of each constituent, the distribution of the
electrical conductivity and flexural strength of parts made using the CM and SLS processes are
obtained, and the similarities and differences of the effects of the various constituents between
these two processes are compared.",,,,,,
"['Spierings, A.B.', 'Levy, G.']",2021-09-28T20:14:52Z,2021-09-28T20:14:52Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88172', 'http://dx.doi.org/10.26153/tsw/15113']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'additive manufacturing', 'density measurement', 'Stainless Steel 316L parts', 'powder grades']",Comparison of Density of Stainless Steel 316L Parts Produced with Selective Laser Melting using Different Powder Grades,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e5dd3f6e-d0e2-48f2-b716-59d3b9b1fb84/download,University of Texas at Austin,"Selective Laser Melting is a powder based additive manufacturing process where the metallic
powder particles are fused to 3D parts using a high energy laser beam. Much work has already
been conducted to investigate the details of the process, suitable materials and process parameters
and further more. As metallic powders are the raw material for this process, there are still a lot of
open questions relating to suitable grain size distributions for dense parts with regard to
productivity, surface quality, mechanical strength and ductility. The present work shows the
results of density measurements of parts, produced using three different particle size distributions
and different energy densities of the laser beam. Two layer thicknesses of 30μm and 45μm were
investigated.
It is shown that without a minimal amount of fine grains, which are able to fill the voids between
the coarse grains, lower scan speeds are needed in order to produce dense parts. Furthermore, the
differences in the relation of the powders to the densities, the layer thicknesses and laser scan
speeds indicate, that the powder grain size distribution plays an important role and that should be
taken into account for optimal results. This work is a contribution to the ASTM initiative F42 for
“Additive Manufacturing”.",,,,,,
"['Parvez, M.M.', 'Chen, Y.', 'Newkirk, J.W.', 'Liou, F.F.']",2021-11-17T23:35:33Z,2021-11-17T23:35:33Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90355', 'http://dx.doi.org/10.26153/tsw/17276']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['fatigue test', 'fatigue performance', '304L', 'stainless steel', 'wrought', 'additive manufacture']",Comparison of Fatigue Performance Between Additively Manufactured and Wrought 304L Stainless Steel Using a Novel Fatigue Test Setup,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c64ff25e-3cf9-44b1-95fd-e074ac6c5ebe/download,University of Texas at Austin,"In this research, a novel adaptive controlled fatigue testing machine was designed
for bending type high cycle fatigue test. A unique dual gauge section Krouse type mini specimen
was designed for simply supported transverse bending. Displacement controlled fatigue tests were
implemented using an electromechanical actuator. The variation in the control signal and load
observed during the test provides unique insights into realizing the deterioration of the specimen
due to fatigue. These analyses were utilized to compare the fatigue performance of wrought and
additively manufactured 304L stainless steel. The influence of the build direction on fatigue
performance was also investigated by testing specimens with 0, 45, and 90 degrees build direction.
These comparisons were carried out at different levels of displacement amplitude.",,,,,,
"['Gibson, A.', 'Weaver, J.M.']",2023-03-30T16:20:38Z,2023-03-30T16:20:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117702', 'http://dx.doi.org/10.26153/tsw/44581']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,A Comparison of Layer Deposition and Open Molding of PETG by Fused Pellet Fabrication in an Additive Manufacturing System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1615ba22-a9cd-4b13-813f-2d583e1ef09e/download,,"Additive manufacturing continues to offer new possibilities in both production and 
economics. The industry has quickly adopted it to rapidly produce parts that would be difficult or 
cost preventative otherwise. Recent innovation has expanded its capabilities, however there are 
still significant limitations. Most AM processes are restricted by materials available, in producing 
large parts, or by not achieving material deposition speeds to make certain products feasible. In 
addition, tight tolerances for features and surfaces cannot be produced without substantial post 
processing. High-speed Fused Pellet Fabrication (FPF) in combination with Hybrid Manufacturing 
(HM) offers expanded capabilities as additive and subtractive process are used within the same 
space. It also allows for a different kind of additive process where an open mold can be cut from 
a substrate and then filled using the FPF process to fabricate parts without layers. This, in 
combination with Large Area Additive Manufacturing (LAAM), enables parts that leverage the 
strengths of new and traditional methods at scales and speeds previously unavailable.",,,,,,
"['Alptug Tanrikulu, Ahmet', 'Ganesh-Ram, Aditya', 'Farhang, Behzad', 'Amerinatanzi, Amirhesam']",2024-03-25T23:29:06Z,2024-03-25T23:29:06Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124336', 'https://doi.org/10.26153/tsw/50944']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Ti6Al4V', 'preheating scan', 'post-heating scan', 'microstructure']",Comparison of Layerwise Preheating and Post-heating Laser Scan on The Microstructure and Mechanical Properties of L-PBF Ti6Al4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b8d491a-35e0-4b45-a742-39fd7198cd6c/download,University of Texas at Austin,"This study aimed to investigate the evolution of the microstructure and mechanical properties of asfabricated laser powder bed fusion (L-PBF) Ti-6Al-4V samples by introducing layerwise pre-heating or
post-heating laser scans. Multiple laser scans, varying in scanning speed at constant power, were examined
before the melting laser scan (pre-heating) or after it (post-heating). The analysis focused on microstructural
features such as porosity, and α-phases lath structure, as well as the hardness response of the material. The
results revealed the additional layerwise scans had a significant impact on reducing porosity by up to 98%
when the additional scan was applied prior to or upon the melting scan. Additional laser scans decreased
the microstructure and mechanical response variation along different orientations. Furthermore, these
findings highlight the potential of layerwise heating strategies to improve the overall quality and
performance of L-PBF Ti-6Al-4V components, thus paving the way for enhanced applications in various
industries such as aerospace.",,,,,,
"['Silverman, T. J.', 'Hall, A.', 'South, B.', 'Yong, W.', 'Koo, J. H.']",2020-03-10T14:18:01Z,2020-03-10T14:18:01Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80207', 'http://dx.doi.org/10.26153/tsw/7226']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Comparison of Material Properties and Microstructure of Specimens Built Using the 3D Systems Vanguard HS and Vanguard HiQ+HSSLS Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ccc9aca-466f-4d1a-be01-7b3018ac6d44/download,,"The HiQ upgrade to the 3D Systems Vanguard selective laser sintering (SLS) machine incorporates a revised thermal calibration system and new control software. The paper compares
the tensile modulus, tensile strength, elongation at break, flexural modulus, Izod impact resistance and microstructure of two batteries of standard specimens built from recycled Duraform
PA (Nylon 12). The first set is built on a Vanguard HS system and the second on the same
system with the HiQ upgrade installed. The upgrade reduces user intervention, decreases total build time and improves surface finish. However, using the default processing parameters,
tensile, flexure and impact properties are all found to decline after the upgrade is installed.",,,,,,
"['Gaytan, S.M.', 'Murr, L.E.', 'Martinez, E.', 'Martinez, J.L.', 'Machado, B.I.', 'Ramirez, D.A.', 'Medina, F.', 'Collins, S.', 'Wicker, R.B.']",2021-09-30T14:44:02Z,2021-09-30T14:44:02Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88259', 'http://dx.doi.org/10.26153/tsw/15200']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['electron beam melting', 'cobalt powder', 'cobalt-based alloy components', 'microstructures', 'mechanical properties', 'femoral implant prototype']",Comparison of Microstructures and Mechanical Properties for Solid Cobalt-Base Alloy Components and Biomedical Implant Prototypes Fabricated by Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/18363426-9113-4471-ba6f-98c8089c6ed5/download,University of Texas at Austin,"The microstructures and mechanical behavior of simple, as-fabricated, solid
geometries (with a density of 8.4 g/cm3), as-fabricated and fabricated and annealed
femoral (knee) prototypes all produced by additive manufacturing (AM) using electron
beam melting (EBM) of Co-26Cr-6Mo-0.2C powder are examined and compared in this
study. Microstructures and microstructural issues are examined by optical metallography,
SEM, TEM, EDS, and XRD while mechanical properties included selective specimen
tensile testing and Vickers microindentation (HV) and Rockwell C-scale (HRC) hardness
measurements. Orthogonal (X-Y) melt scanning of the electron beam during AM
produced unique, orthogonal and related Cr23C6 carbide (precipitate) cellular arrays with
dimensions of ~2μm in the build plane perpendicular to the build direction, while
connected carbide columns were formed in the vertical plane, parallel to the build
direction.",,,,,,
"['Sharma, Raghav', 'Le, Thao', 'Song, Jiaxu', 'Harms, Ethaniel', 'Sowa, Daniel', 'Grishin, Alex', 'Bhate, Dhruv']",2021-11-09T20:24:44Z,2021-11-09T20:24:44Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90157', 'http://dx.doi.org/10.26153/tsw/17078']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['modeling', 'elastic behavior', 'plastic behavior', 'honeycomb structures', 'fused deposition modeling', 'additive manufacturing', 'FEA']",A Comparison of Modeling Methods for Predicting the Elastic-Plastic Response of Additively Manufactured Honeycomb Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ed739cd-e7ca-41c0-ad72-3c5e35566e39/download,University of Texas at Austin,"Valid and accurate models describing the mechanical behavior of additively manufactured
cellular materials are crucial to enabling their implementation in critical-to-function parts. Broadly
speaking, the modeling approaches commonly used in the literature fall into three categories. Each
of these differs in the level of discretization at which the cellular behavior is modeled: at the level
of each material point, at the level of the unit cell or at the level of a connecting member that
constitutes a unit cell. Each of these three approaches relies on different characterization
techniques and the way in which the resulting data is leveraged in the development of the model.
In this work, we critically examine all three modeling approaches using FEA and compare their
accuracy in the prediction of the elastic and plastic behavior of experimentally characterized
hexagonal honeycomb structures made with Fused Deposition Modeling, and discuss the pros and
cons of each method.",,,,,,
"['Diaz, J.', 'Caballero, K.', 'Medrano, V.A.', 'Arrieta, E.', 'Benedict, M.', 'Godfrey, D.', 'Wicker, R. B.', 'Medina, F.']",2023-03-29T16:31:36Z,2023-03-29T16:31:36Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117682', 'http://dx.doi.org/10.26153/tsw/44561']",eng,2022 International Solid Freeform Fabrication Symposium,Open,aluminum F357,Comparison of Multiple Heat Treatments by Observing Mechanical Properties and Microstructure of LPBF Fabricated Aluminum F357,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4ab3b9c1-50f1-457c-b359-8135936007c1/download,,"In this paper, Aluminum F357 (AlSi7Mg), a material which is widely used in the 
automotive, aerospace, and additive manufacturing industries, will be analyzed after performing 
several heat treatments to enhance the properties of the material. However, there is currently no 
standard for the usage and heat treating of F357 alloy; for that reason, ASTM F3318 standard will 
be followed for heat treating it. Having a comprehensive study on the performance of 3D-printed 
F357 benefits the automotive, military and aerospace industries due to the numerous casted 
components already in service and many becoming legacy components. This work presents 
mechanical and microstructural properties of F357 specimens fabricated with SLM technology 
and subjected to heat treatments; as-built, stress-relief, T6, hot isostatic pressing (HIP), and 
HIP+T6 heat treatments were applied. Furthermore, with the interest of the alloy performance in-
service conditions, the specimens were subjected to artificial thermal aging.",,,,,,
"Leigh, David K.",2021-10-06T20:40:10Z,2021-10-06T20:40:10Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88438', 'http://dx.doi.org/10.26153/tsw/15375']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'compression molding', 'Polyamide-11', 'Ultimate Tensile Strength', 'Elongation at Break']",A Comparison of Polyamide 11 Mechanical Properties Between Laser Sintering and Traditional Molding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a419d0d-0d6f-4189-937f-d29e1e61ff5f/download,University of Texas at Austin,"Tensile properties of laser sintering grade Polyamide-11 are processed using laser
sintering, compression molding, and injection molding and the resultant mechanical properties
are reported. The primary contributor to the enhanced mechanical properties of injection molded
specimens is a fully healed polymer melt with preferred polymer chain orientation. It can be
shown that laser sintering and compression molding specimens have comparable to compression
molding specimens Ultimate Tensile Strength (UTS) and Elongation at Break (EOB).",,,,,,
"['Ameen, Ahamed', 'Janik, Vit', 'Nicholas, Joanna', 'Zhang, Xiang', 'Seow, Cui Er']",2024-03-26T23:06:32Z,2024-03-26T23:06:32Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124441', 'https://doi.org/10.26153/tsw/51049']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['wire-arc DED', 'low alloyed steel', 'interpass surface temperature', 'interpass dwell time', 'thermo-couple measurement']",Comparison of process control methods for wire-arc directed energy deposition of low carbon steels with in-situ temperature measurement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53101007-760e-4895-9b96-46330227d74b/download,University of Texas at Austin,"Additive manufacturing (AM) techniques enable the production of near-net shape parts.
Wire-arc direct energy deposition (WA-DED) can achieve a higher deposition rate among other
available metal AM methods. Conventional arc welding requires a maximum interpass
temperature to limit any reduction in mechanical properties, but this may not be practicable for
wWA-DED. In this study, two interpass process control methods, one with maximum interpass
surface temperature and the other with constant dwell time, were adopted to deposit low alloyed
steel walls while maintaining the same feedstock and heat input values. Thermocouples were
inserted at three different positions in the walls during deposition, to record the thermal
profiles. Test samples extracted from walls exhibited similar tensile strength (~10 MPa
difference) and hardness values. Microstructural evaluation showed the presence of interlayer
regions with alternating coarse and fine bands of ferrite grains, irrespective of the interpass
control method. These findings suggest that dwell time control is better for productivity.",,,,,,
"['Shrestha, Rakish', 'Simsiriwong, Jutima', 'Shamsaei, Nima']",2021-11-18T00:22:18Z,2021-11-18T00:22:18Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90368', 'http://dx.doi.org/10.26153/tsw/17289']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['stress gradient', 'fatigue', '316L stainless steel', 'surface roughness']",Comparison of Rotating-Bending and Axial Fatigue Behaviors of LB-PBF 316L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e72c83ca-00c4-46bd-a799-e67d70adf8ca/download,University of Texas at Austin,"Additive manufactured (AM) materials are prone to internal defects such as entrapped gas
pores and lack of fusions along with having a rough surface. There are different types of fatigue
tests that are used to characterize the effects of such defects on the structural integrity of AM parts.
The present study aims to investigate the effect of stress gradient on the fatigue behavior of 316L
stainless steel (SS), fabricated using a laser beam powder bed fusion (LB-PBF) process. Axial
fatigue tests are performed on as-built (non-machined) LB-PBF 316LSS round specimens with
uniform gage section, while rotating bending fatigue tests are conducted on hourglass specimens
(i.e. reduced gage section). Fatigue tests revealed that the specimens subjected to the axial loading
exhibited lower fatigue resistance compared to the specimens failed under rotating bending test.
Such differences in the fatigue life was attributed to the variation in the stress distribution resulting
from different loading types and its effect on the fatigue crack propagation. Fractography analysis
conducted to determine the failure mechanism showed that all of the cracks initiated from the
surface of the specimen irrespective to the loading conditions. Furthermore, fracture surface
observed for LB-PBF 316L SS specimens resembled a typical fracture surface of notched
specimens, which supports the fact that for the as-built specimens cracks initiates from the micro-notches as a result of layer wise fabrication in AM process.",,,,,,
"['Roach, Michael', 'Williamson, R. Scott', 'Pegues, Jonathan', 'Shamsaei, Nima']",2021-11-11T15:19:10Z,2021-11-11T15:19:10Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90217', 'http://dx.doi.org/10.26153/tsw/17138']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['stress corrosion cracking', 'environmentally assisted cracking', 'titanium alloy', 'tensile properties']",A Comparison of Stress Corrosion Cracking Susceptibility in Additively-Manufactured and Wrought Materials for Aerospace and Biomedical Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b28ef43d-a78a-4bb3-bba1-3cbd7d0914c4/download,University of Texas at Austin,"Additive manufacturing (AM) is becoming an increasingly popular method in both
aerospace and biomedical industries. Titanium alloys are increasingly common in additive
manufactured applications due to their excellent strength to weight ratio and biocompatibility.
Traditional wrought Ti-6Al-4V alloys show little sensitivity to stress corrosion cracking (SCC)
when subjected to in-vitro conditions. In AM applications the alloy powder is often sifted and
reused multiple times which often results in a degradation of the powder’s shape. Recent studies
have also shown that the oxygen content of additive powders increases with repeated powder use
which may increase the susceptibility of the resulting parts to SCC. This research compares the
microstructural characteristics and tensile SCC behavior of AM Ti-6Al-4V parts fabricated from
new and recycled powder in distilled H2O, salt water, and Ringers solution. Additionally, the effect
of surface finish is investigated for each microstructure comparing the as-built surfaces to
machined and polished surfaces.",,,,,,
"['De La Cruz, Alex', 'Medina, Francisco', 'Arrieta, Edel', 'Weston, Luke', 'Benedict, Mark', 'Gibson, Theo']",2024-03-27T03:42:25Z,2024-03-27T03:42:25Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124472', 'https://doi.org/10.26153/tsw/51080']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser powder bed fusion', 'Ti6Al4V', 'surface texture', 'surface morphology']",Comparison of Surface Texture from Various Surface Morphology Techniques for Evaluating As-Built Ti6Al4V Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d8669a2c-7452-4046-8cb6-dd9be6890d39/download,University of Texas at Austin,"Additive manufacturing (AM) is capable of creating unique and complex geometries that
conventional methods cannot achieve. The applications for AM have been rapidly increasing
across a variety of sectors, particularly for biomedical and aerospace components, the relatively
low production volumes and high demand for customizability in both sectors are especially
amiable to AM. However, without post-processing, AM components contain a variety of flaws,
such as surface roughness and porosity, that can partially be mitigated by process parameters like
scan speed and laser power. Surface roughness is a flaw present for every as-built AM surface
that serves as an array of sites for every mode of material failure to occur. Common surface
roughness measurements involve the use of optical and contact stylus profilometry. However, xray Computed Tomography (xCT) is already the most widely used method of analyzing AM
parts for porosity, inclusions, and various other flaws. In terms of resolution, xCT should be fully
capable of analyzing surface roughness and is the only method of the three investigated that can
inspect interior geometries. Therefore, evaluating xCT as a fully inclusive analysis method for
AM parts is advantageous. In this study, we compared three surface characterization
technologies, xCT, optical profilometry, and contact stylus profilometry. The comparison of
these technologies is being done on as-built Laser Powder Bed Fusion (L-BPF) Ti6AI4V fourpoint bending fatigue samples. Further understanding the difference among each of the
technologies will aid ongoing research on developing a standard for xCT surface characterization
while also providing more knowledge and insight into each technique and what can be expected.
Each of the samples was produced by varying scanning speed and laser power, resulting in
different surface textures. Preliminary results show deviations of Sa _%, Sz _%, Sv _%, and Sku
_% between the xCT and optical microscopy methods are comparable between these two
methods.",,,,,,
"['Chu, Jane', 'Engelbrecht, Sarah', 'Graf, Greg', 'Rosen, David W.']",2021-09-23T22:08:07Z,2021-09-23T22:08:07Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88035', 'http://dx.doi.org/10.26153/tsw/14976']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['cellular materials', 'lattice structures', 'design synthesis', 'particle swarm optimization', 'least square minimization', 'additive manufacturing']",A Comparison of Synthesis Methods for Cellular Structures with Application to Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5e7d7b2-681e-4db7-87ac-fdda3c82826a/download,,"Cellular material structures, such as honeycombs and lattice structures, have been
engineered at the mesoscale for high performance and multifunctional capabilities. We desire
efficient algorithms for searching the large, complex design spaces associated with cellular
structures. In this paper, we present a comparison of two synthesis methods, Particle Swarm
Optimization (PSO) and least-squares minimization (LSM), for the design of components
comprised of cellular structures. Computational characteristics of the algorithms are reported for
design problems with hundreds of variables. Constraints from SLS and direct-metal
manufacturing processes are incorporated to ensure that resulting designs are realizable. Two 2-
dimensional examples are used to study the characteristics of the proposed synthesis methods.",,,,,,
"['Zeng, Kai', 'Teng, Chong', 'Xu, Sally', 'Sublette, Tim', 'Patil, Nachiket', 'Pala, Deepankar', 'Stucker, Brent']",2021-10-18T21:56:44Z,2021-10-18T21:56:44Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89265,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['simulation infrastructure', 'simulation code', 'computational speed', 'metal-based additive manufacturing', '3DSIM', 'ANSYS', 'University of Louisville']",A Comparison of the Computational Speed of 3DSIM Versus ANSYS Finite Element Analyses for Simulation of Thermal History in Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e7297114-1d98-4428-b025-cd28a7cc0f22/download,University of Texas at Austin,"A new simulation infrastructure for predicting the effects of changes in process
parameters on mechanical properties, residual stress/strain, crystal structure, and other micro &
macro features of components made using metal-based AM techniques has been developed at the
University of Louisville (UofL) and is being commercialized by 3DSIM, LLC. Based upon its
MatLab and Fortran code, UofL personnel predicted their multi-scale, multi-physics finite
element solvers should solve for thermal history and residual stress evolution many orders of
magnitude faster than competing tools while achieving better solution accuracy. In order to test
this contention, a series of computational experiments were designed to benchmark the
performance of the code being commercialized by 3DSIM against a well-respected simulation
tool, ANSYS. The results of these initial studies indicate the 3DSIM architecture is significantly
faster than ANSYS for simulating metal-based AM processes.",,,,,,
"['Yang, Yu', 'Obahor, Omoghene Osaze', 'Bao, Yaxin', 'Sparks, Todd E.', 'Ruan, Jianzhong', 'Stroble, Jacquelyn Kay', 'Landers, Robert', 'Newkirk, Joseph', 'Liou, Frank']",2020-03-02T15:20:25Z,2020-03-02T15:20:25Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80131', 'http://dx.doi.org/10.26153/tsw/7152']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Flash,Comparison of Thermal Properties of Laser Deposition and Traditional Welding Process via Thermal Diffusivity Measurement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f388914f-ad1f-4766-bfa3-ecee9ac4f4eb/download,,"Laser deposition is an effective process for mold and die repair. In order to improve the part
repair qualityˈthe process impact on thermal diffusivity and thermal conductivity needs to be
understood for laser deposited, welded and virgin H13. In this paper, H13 tool steel samples
were made by laser deposition, welding and virgin H13 and then cut into pieces. Experiments
were conducted to investigate the thermal diffusivity and conductivity. A laser flash method is
used to test these samples. The future work and opportunities are also summarized.",,,,,,
"['Loeber, L.', 'Biamino, S.', 'Ackelid, U.', 'Sabbadini, S.', 'Epicoco, P.', 'Fino, P.', 'Eckert, J.']",2021-10-05T14:24:15Z,2021-10-05T14:24:15Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88377', 'http://dx.doi.org/10.26153/tsw/15316']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'electron beam melting', 'titanium aluminides']",Comparison off Selective Laser and Electron Beam Melted Titanium Aluminides,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03ec721a-a0bf-48bf-afb6-d0f66135474e/download,University of Texas at Austin,"In the following paper we present the investigation of microstructure and mechanical properties
produced by selective laser melting (SLM) and electron beam melting (EBM). The chosen alloy is a Ti-(46-
48)Al-2Cr-2Nb alloy which has a great potential in replacing heavy weight Ni-base superalloys in turbine
blades. Cylindrical specimens were produced and characterized by optical microscopy (OM), scanning electron
microscopy (SEM) and chemical analysis to determine the microstructure and composition. In addition
compression tests at room and elevated temperatures (700-800 °C) were carried out to identify the mechanical
properties of the alloy.",,,,,,
"['Dai, Kun', 'Li, Xiaoxuan', 'Shaw, Leon L.']",2019-11-20T16:30:55Z,2019-11-20T16:30:55Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78474', 'http://dx.doi.org/10.26153/tsw/5559']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Thermal Modeling,Comparisons Between Thermal Modeling and Experiments in Laser-Densified Dental Powder Bodies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ec597b85-4168-4b5c-a8b3-b8da0ab63b0e/download,,"A three-dimensional thermal finite element model including the effect of the powder-tosolid transition has been developed to investigate the transient temperature distribution during
laser densification of dental powder bed for the layer-by-layer fabrication. The model
encompasses the effects of the temperature- and porosity-dependent thermal conduction and
radiation as well as the temperature-dependent natural convection. The simulation result is
compared with the experiments which establish the temperature dependence of the dental
porcelain microstructure and utilize this dependence to construct the temperature distribution
profile. It is found that the trend of the simulation result matches the experiments very well.","The authors gratefully acknowledge financial support provided by
the National Science Foundation under Grant Nos: DMI-9908249 and DMI-0218169.",,,,,
"['Fearon, E.', 'Watkins, K. G.']",2020-02-14T15:50:03Z,2020-02-14T15:50:03Z,8/31/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79988', 'http://dx.doi.org/10.26153/tsw/7013']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Direct Laser Deposition,Compensation for Uneven Surfaces When Building Laser Deposited Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/46187ee2-951e-413e-82ee-d634d4837d3b/download,,"Direct Laser Deposition (DLD) is a blown-powder laser deposition process that can be
used to quickly produce, modify or repair fully-dense metallic parts by a layered manufacturing
method. However, uneven substrate surfaces often cause variation in the deposited layer which
is magnified by succeeding layers. Research carried out at the University of Liverpool has
resulted in a non-feedback layer height controlling process based on controlling the shape of the
powder streams emitted from a four-port side feed nozzle. This method limits deposited layer
height by causing a sharp reduction of catchment efficiency in the vertical plane at a fixed
distance from the powder feed nozzle, and is therefore capable of depositing a consistent layer
height in spite of power, powder flow or process velocity variation. This paper demonstrates
how this method of layer height control can compensate for irregular substrate surfaces in the
production of accurate DLD parts.",,,,,,
"['Manetsberger, K.', 'Shen, J.', 'Muellers, J.']",2019-10-18T15:25:53Z,2019-10-18T15:25:53Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76238', 'http://dx.doi.org/10.26153/tsw/3327']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Polymer,Compensation of Non-Linear Shrinkage of Polymer Materials in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5f3cc1c7-17b7-4eb4-9cc0-b06ad23cf663/download,,"Inaccuracies in the selective laser sintering (SLS) process using polymer materials are typically
caused by inhomogeneous shrinkage due to inhomogeneous temperature distribution in the
powder bed of the SLS machine. These shrinking effects lead to stress in the sintered parts,
causing the part to distort. The inhomogeneous shrinkage of benchmark parts has been
compensated empirically in a former work. The results cannot been transferred to all geometries,
because each geometry requires a specific temperature for laser sintering and, thus, has its own
related shrinkage distribution. In a new theoretical approach, shrinkage behavior is to be
integrated in a thermal simulation of the SLS process and the thermal shrinkage calculated prior
to the building process. In the following, experimental data of the temperature- and pressuredependent shrinkage of laser-sintered powder samples is presented. Possible theories for a
physical model of thermal shrinkage are discussed. In particular, these models have to consider
granular characteristics such as internal friction, particle sliding, and powder compaction.",,,,,,
"['Limaye, Ameya', 'Rosen, David W.']",2020-02-21T20:56:14Z,2020-02-21T20:56:14Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80071', 'http://dx.doi.org/10.26153/tsw/7092']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Mask Projection Stereolithography,Compensation Zone Approach to Avoid Z Errors in Mask Projection Stereolithography Builds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/49b18c6d-d459-446a-bf7a-b3b56cb62f95/download,,"Print-through results in unwanted polymerization occurring beneath a part cured using
Mask Projection Stereolithography (MPSLA) and thus creates error in its Z dimension. In this
paper, the ""Compensation zone approach"" is proposed to avoid this error. This approach entails
modifying the geometry of the part to be cured. A volume (Compensation zone) is subtracted
from underneath the CAD model in order to compensate for the increase in the Z dimension that
would occur due to Print-through. Three process variables have been identified: Thickness of
Compensation zone, Thickness of every layer and Exposure distribution across every image used
to cure a layer. Analytical relations have been formulated between these process variables in
order to obtain dimensionally accurate parts. The Compensation zone approach is demonstrated
on an example problem.",,,,,,
"['Zhang, Meng', 'Sun, Chen-Nan', 'Zhang, Xiang', 'Chin Goh, Phoi', 'Wei, Jun', 'Li, Hua', 'Hardacre, David']",2021-11-02T15:28:25Z,2021-11-02T15:28:25Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89829,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'porosity', 'microstructure', 'powder bed fusion', 'selective laser melting', 'stainless steel 316L']",Competing Influence of Porosity and Microstructure on the Fatigue Property of Laser Powder Bed Fusion Stainless Steel 316L,Conference paper,https://repositories.lib.utexas.edu//bitstreams/48e8051a-eb95-4ff1-9205-12cfdc4be7d2/download,University of Texas at Austin,"Crack initiation constitutes a large portion of the total life for parts under high cycle
fatigue loading. Materials made by the laser powder bed fusion (L-PBF) process contain
unavoidable process-induced porosity whose effect on the mechanical properties needs to be
considered for fatigue applications. Results from this work show that not all pores in L-PBF parts
promote fatigue crack initiation. The length scale of local microstructure defects, i.e. grain
boundary, could be larger than the pores and in such cases they are the primary cause for crack
initiation. Samples were produced in this work to demonstrate the critical defect size responsible
for the transition between the porosity-driven and microstructure-driven failure modes.",,,,,,
"['Morris, S.J.', 'Dudman, J.P.R.', 'Körner, L.', 'Melo, P.', 'Newton, L.H.', 'Clare, A.T.']",2021-11-01T22:48:11Z,2021-11-01T22:48:11Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89787,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['advanced surfaces', 'complex functional surface', 'additive manufacturing', 'methodology']",Complex Functional Surface Design for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cfbd5bdd-88b8-423d-ad13-fdd5d2009341/download,University of Texas at Austin,"This paper presents a new methodology for the creation of advanced surfaces which
can be produced by Additive Manufacturing (AM) methods. Since there is no cost for enhanced
complexity, AM allows for new capabilities in surface design. Micro-scale surface features
with varying size, shape and pitch can be manufactured by Two-Photon Polymerisation (2PP).
Computer-Aided Design (CAD) tools allowing for this variation to be incorporated into the
surface design are only just emerging. With the presented methodology, surfaces are created
from a single feature design. Variation is applied to the surface features through algorithmic
design tools, allowing for arrays of hundreds of unique features can be created by non-CAD
experts. The translation of these algorithmic expressions from CAD to a physical surface is
investigated. Using the proposed methodology, 2PP is used to create quasi stochastic surfaces
for the purpose of enhancing the biointegration of medical implants against current state-of-the-art.",,,,,,
"['Li, Longmei', 'Bellehumeur C., Sun', 'Gu, P.']",2019-10-10T17:01:54Z,2019-10-10T17:01:54Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76173', 'http://dx.doi.org/10.26153/tsw/3262']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Modeling,Composite Modeling and Analysis of FDM Prototypes for Design and Fabrication of Functionally Graded Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aad86b09-ab35-4444-8869-707364c683f1/download,,"Solid Freeform Fabrication technologies have potential to manufacture parts with locally controlled properties (LCP), which would allow concurrent design of part’s geometry and desired
properties. To a certain extent, Fused Deposition Modelling (FDM) has the ability to fabricate
parts with LCP by changing deposition density and deposition orientation. To fully exploit this
potential, this paper reports a study on the mechanical properties of FDM prototypes, and related
materials and fabrication process issues. Both theoretical and experimental analyses of mechanical
properties of FDM parts were carried out. To establish the constitutive models, a set of equations
is proposed to determine the elastic constants of FDM prototypes. An example is provided to
illustrate the model with LCP using FDM.","The financial support for this research was provided by the National Sciences and Engineering
Research Council of Canada (NSERC) through Research Grant OGP0192173.",,,,,
"['Gervasi, V.R.', 'Crockett, R.S.']",2019-03-01T17:41:46Z,2019-03-01T17:41:46Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73520', 'http://dx.doi.org/10.26153/tsw/670']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['gradient materials', 'stereolithography']",Composites with Gradient Properties From Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69a55609-9615-40ad-a3e8-599589580d87/download,,"TetraCast is a build style developed by Milwaukee School ofEngineering involving
stereolithography patterns produced with an open cellular structure inside a surface shell.
Composites are created using this pattern as a host fora filler material, generally epoxy matrices
loaded with various fibers or microspheres. Regions within a singleobjectrrray be separated by
thin barriers, allowing filling with different matrix materials.to create regiollsof differing.local
properties. The internal structure can also be continually graded in thickness to prodUl::e
composites with properties ranging from that ofthe fillermaterial to that ofthe TetraCast
material (currently stereolithography epoxy or FDM ABS)",,,,,,
"['Murphy, D.', 'Fashanu, O.', 'Spratt, M.', 'Newkirk, J.', 'Chandrashekhara, K.']",2021-11-30T21:10:20Z,2021-11-30T21:10:20Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90551', 'http://dx.doi.org/10.26153/tsw/17470']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'AlSi10Mg', 'compression', 'bending', 'tension']",Compressive and Bending Performance of Selectively Laser Melted AlSi10Mg Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9e08dbc-8f5e-4fd8-8cfd-f8f2c6a2b4e0/download,University of Texas at Austin,"Selective laser melting (SLM) is a widely used additive manufacturing technique that
effectively manufactures complex geometries such as cellular structures. However, challenges
such as anisotropy and mechanical property variation are commonly found due to process
parameters. In a bid to utilize this method for the commercial production of cellular structures, it
is important to understand the behavior of a material under different loading conditions. In this
work, the behavior of additively manufactured AlSi10Mg under compression, bending, and tension
loads was investigated. Vertical and horizontal build directions are compared for each type of
loading. Specimens were manufactured using the reduced build volume (RBV) chamber of the
Renishaw AM 250 SLM machine.",,,,,,
"['Meng, Liang', 'Wang, Zemin', 'Zeng, Xiaoyan']",2021-11-30T21:48:46Z,2021-11-30T21:48:46Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90561', 'http://dx.doi.org/10.26153/tsw/17480']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['bio-inspired structure', 'selective laser melting', 'NSGA-II', 'multi-layers']",Compressive Properties Optimization of a Bio-Inspired Lightweight Structure Fabricated via Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91484285-2bbc-473c-b8be-32195bf2c4c2/download,University of Texas at Austin,"Compressive properties optimization of a bio-inspired lightweight structure is
developed by Response Surface Methodology (RSM) and Non-dominated Sorting
Genetic Algorithm II (NSGA-II). Multi-layered bio-inspired structures of a Ti6Al4V
alloy are designed and fabricated by Selective Laser Melting. The results show that
the optimized structure parameters of bio-inspired structures can be obtained by RSM
and NSGA-II. The relative error rate of experimental results and response values is
less than 10%. Moreover, increasing the number of layers cannot effectively improve
energy absorption (EA) and specific energy absorption (SEA) for multi-layered
bio-inspired structures. The damage process of bio-inspired structures with different
core-arranged configurations fails layer by layer. The load-displacement curves and
damage process of FE simulations are consistent with the experimental results.",,,,,,
"['Hu, Yingbin', 'Wang, Hui', 'Ning, Fuda', 'Cong, Weilong', 'Li, Yuzhou']",2021-10-26T20:12:32Z,2021-10-26T20:12:32Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89573,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser engineered net shaping (LENS)', 'TiBw reinforcement', 'titanium matrix composites (TMCs)', 'compressive properties']",Compressive Property Comparisons Between Laser Engineered Net Shaping of In Situ TiBw-TMCs and Cp-Ti Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83aa182d-d408-49fa-92d4-8fa8c0786e85/download,University of Texas at Austin,"Titanium (Ti) and its alloys are widely used in chemical, astronautical, and biomedical
industries. However, their poor load endurance properties affect their fields of applications
especially under severe loading conditions. To enhance these properties, TiBw reinforcement
was synthesized by in situ chemical reaction between elemental Ti and boron. Strong interfacial
bonding between TiBw reinforcement and Ti matrix was obtained due to the in situ chemical
reaction. Owing to its capability of producing difficult-to-machine bulk composites with uniform
properties, laser engineered net shaping (LENS) technique was utilized to fabricate TiBw
reinforced Ti matrix bulk composites. Few researches have been reported on these three-dimensional metal based bulk composites by using LENS. In this work, effects of TiBw
reinforcement and laser power on compressive properties were investigated. The microstructures
of the fabricated parts were observed and analyzed by using scanning electron microscopy.",,,,,,
"['Gautam, Rinoj', 'Sridharan, Vijay Shankar', 'Teh, Wee Lee', 'Idapalapati, Sridhar']",2021-11-30T21:22:25Z,2021-11-30T21:22:25Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90552', 'http://dx.doi.org/10.26153/tsw/17471']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'strut-reinforced kagome', 'SRK', 'ABS', 'compressive loading', 'fused deposition modeling']",Compressive Response of Strut-Reinforced Kagome with Polyurethane Reinforcement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ff1f2d9-5b94-4e42-a99d-213f0083a10e/download,University of Texas at Austin,"Lattice structures find immense application in lightweight structures for their high specific
strength, modulus, and energy absorption. Strut-reinforced Kagome (SRK) structures provide
better compressive performance compared to many existing lattice structures. In this study, the
performance of acrylonitrile butadiene styrene (ABS) SRK lattice structures, fabricated by fused
deposition modeling, under compression loading is investigated. Further, SRK structures were
filled with different polyurethane in the empty space and their effect on the compressive
performance was examined. The SRK structure demonstrated abrupt failure at the joints in the
vicinity of face sheet, thereby reducing the energy absorption of the structure. The SRK with
flexible foam (low-density polyurethane foam) had no significant effect on peak failure load and
moduli, whereas energy absorption per unit mass was higher by 16.5%. The SRK with the rigid
foam (high-density foam) displayed not only the better energy absorption per unit mass (116%)
but also different failure behavior than SRK only.",,,,,,
"['Sereshk, Mohammad Reza Vaziri', 'Triplett, Kevin', 'St. John, Christopher', 'Martin, Keith', 'Gorin, Shira', 'Avery, Alec', 'Byer, Eric', 'St Pierre, Conner', 'Soltani-Tehrani, Arash', 'Shamsaei, Nima']",2021-11-30T21:26:43Z,2021-11-30T21:26:43Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90553', 'http://dx.doi.org/10.26153/tsw/17472']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['mechanical properties', 'lattice structures', 'finite element method', 'laser beam powder bed fusion']",A Computational and Experimental Investigation into Mechanical Characterizations of Strut-Based Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61d6f7cd-0fe7-4e50-a9ad-a9d1c57e8185/download,University of Texas at Austin,"Strut-based lattices are widely used in structural components for reducing weight. Additive
manufacturing has provided a unique opportunity to fabricate such complex geometries. In
addition to the unit cell type, the strut size and shape can significantly affect the mechanical
properties achieved. Therefore, furnishing a lattice structure library may help in selecting the
appropriate combination of lattice types and dimensions for targeted mechanical performance for
a specific application. This study presents a method for determination of mechanical properties,
including strength and stiffness, for lattice structures. Finite element (FE) simulations are used as
the main tool and the results of which are to be verified by mechanical testing of samples fabricated
using the laser beam powder bed fusion (LB-PBF) process. Proper lattices with the stiffness
matched with associated bone were determined. However, the result indicated that lattices made
from 316L SS are not strong enough for bone implants. The proposed procedure can be used for
other unit cells of interest due to its generality.",,,,,,
"['Das, Suman', 'Hollister, Scott J.', 'Flanagan, Colleen', 'Adewunmi, Adebisi', 'Bark, Karlin', 'Chen, Cindy', 'Ramaswamy, Krishnan', 'Rose, Daniel', 'Widjaja, Erwin']",2019-10-22T17:33:44Z,2019-10-22T17:33:44Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76321', 'http://dx.doi.org/10.26153/tsw/3410']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Scaffolds,"Computational Design, Freeform Fabrication and Testing of Nylon-6 Tissue Engineering Scaffolds",Conference paper,https://repositories.lib.utexas.edu//bitstreams/8288f87e-18aa-428c-a074-a7a36d780f22/download,,"Approximately 100,000 people in the US alone suffer from TMJ disease to the extent
that surgical reconstruction is needed. In order to reconstruct a whole joint such as the
TMJ, advanced, novel fabrication methods are needed to build complex, threedimensional scaffolds incorporating multiple, functionally graded biomaterials and
porosity that will enable the simultaneous growth of multiple tissues including blood
vessels. The aim of this research is to develop, demonstrate and characterize techniques
for fabricating such scaffolds by combining solid freeform fabrication and computational
design methods. When fully developed, such techniques are expected to enable the
fabrication of tissue engineering scaffolds endowed with functionally graded material
composition and porosity exhibiting sharp or smooth gradients. As a first step towards
realizing this goal, we have designed and fabricated scaffolds with various architectures
in Nylon-6, a biocompatible polymer using selective laser sintering. Results of biocompatibility, mechanical testing and implantation are presented.","The authors gratefully acknowledge Honeywell Plastics for a generous donation of
Nylon-6 powder.",,,,,
"['Basak, Amrita', 'Acharya, Ranadip', 'Bansal, Rohan', 'Das, Suman']",2021-10-21T18:15:59Z,2021-10-21T18:15:59Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89416,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['equiaxed superalloys', 'Scanning Laser Epitaxy', 'optimization', 'gas turbine']",Computational Modeling and Experimental Validation of Melting and Solidification in Equiaxed Superalloys Processed through Scanning Laser Epitaxy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f0302416-e7a2-403c-9e8d-f173649a69e5/download,University of Texas at Austin,"This paper focuses on simulation-based optimization of the Scanning Laser Epitaxy (SLE)
process applied to gas turbine hot-section components made of nickel-base superalloys. SLE
creates equiaxed, directionally-solidified and single-crystal microstructures from superalloy
powders melted onto like-chemistry substrates using a fast scanning, high power laser beam. In
this paper, a transient coupled flow-thermal approach is implemented to accurately simulate the
melting and solidification process in SLE. The laser movement is modeled as a Gaussian moving
heat source, and the thermophysical properties of the alloys are adjusted based on the thermal
field. Simulations for different superalloys such as IN100, René 80 and MAR-M247 are
performed and the instantaneous melt pool characteristics are recorded. Comparisons of the
simulations with experimental results show reasonably good agreement for the melt depth.
Feedback control is implemented, and demonstrated to produce superior quality SLE deposits.",This work is sponsored by the ONR through grants N00014-11-1-0670 and N00014-14-1-0658.,,,,,
"['Acharya, Ranadip', 'Bansal, Rohan', 'Gambone, Justin J.', 'Cilino, Paul', 'Das, Suman']",2021-10-06T21:38:23Z,2021-10-06T21:38:23Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88452', 'http://dx.doi.org/10.26153/tsw/15389']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Scanning Laser Epitaxy', 'nickel-based superalloys', 'single-crystal structures', 'equiaxed, directionally-solidified structures', 'CMSX-4 alloy']",Computational Modeling and Experimental Validation of Microstructural Development in Superalloy CMSx-4 Processed through Scanning Laser Epitaxy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d9fb5e6f-b2e9-40a4-9785-7d82c9473567/download,University of Texas at Austin,"This paper focuses on computational modeling of Scanning Laser Epitaxy (SLE), an
additive manufacturing technology being developed at Georgia Tech for the creation of
equiaxed, directionally-solidified or single-crystal structures in nickel-based superalloys. The
thermal modeling of the system, carried out in a commercial CFD software package, simulates a
heat source moving over a powder bed and dynamically adjusts the property values for
consolidating CMSX-4 alloy powder. For any given position of the beam, the geometrical
parameters of and the temperature gradient in the melt pool are used to estimate the resulting
solidification microstructure. Detailed study of the flow field also revealed formation of
rotational vortices in the melt pool. Microstructural predictions are shown to be in good
agreement with experimental metallography. This work is sponsored by the Office of Naval
Research through grant N00014-11-1-0670.",,,,,,
"['Zhang, Xiaobing', 'Tuffile, Charles', 'Cheng, Bo']",2021-11-18T17:47:05Z,2021-11-18T17:47:05Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90445', 'http://dx.doi.org/10.26153/tsw/17366']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'SLM', 'computational fluid dynamics', 'CFD', 'discrete phase method', 'DPM', 'gas flow', 'spatter']",Computational Modeling of the Inert Gas Flow Behavior on Spatter Distribution in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/74fb6b05-5f1e-4e86-bac6-535f5eb91df3/download,University of Texas at Austin,"In the selective laser melting (SLM) process, the spatter, introduced by moving melt pools,
can contaminate the build region and potentially reduce the part quality. A well-designed inert gas
flow system can help to effectively remove the process emissions. Therefore, it is critical to
understand the flow characteristics as well as the interactions between gas flow and spatter. In this
study, a Computational Fluid Dynamics (CFD) model for the SLM gas flow system has been
developed to simulate the complicated flow behavior in the chamber. The generation of spatter
over the build region has been simulated by a discrete phase model (DPM). The Eulerian-Lagrangian modeling technique has been applied to accurately capture the influence of gas flow
on ejected spatter. The process variables that can significant affect the gas flow efficiency in the
chamber, such as inlet design, volume flow rate and material property, have been numerically
investigated.",,,,,,
"['Rosser, J.', 'Megahed, M.', 'Mindt, H.-W.', 'Brown, S.G.R.', 'Lavery, N.P.']",2021-11-18T17:11:02Z,2021-11-18T17:11:02Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90432', 'http://dx.doi.org/10.26153/tsw/17353']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['line tracks', 'laser tracks', 'IN625', 'laser powder bed fusion']",Computational Modelling and Experimental Validation of Single In625 Line Tracks in Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e41c0b80-19d4-48ac-8ea2-fa6ff662d859/download,University of Texas at Austin,"Laser track experiments are performed using INCONEL® nickel-based powder alloy,
IN625, in a Powder Bed Fusion (PBF) system. Optical microscopy is used to obtain key track
dimensions and morphology for various machine parameters, allowing direct validation of ESI
Group’s ICME suite of tools for modelling AM. The high-fidelity powder bed model simulates
the melt pool formation based on solution of the Navier-Stokes equations and heat transfer,
radiative powder-laser interaction, phase change, surface tension, Marangoni forces and recoil
pressure. Models are enhanced by measured thermophysical material properties. Validation of
the solidified melt geometry showing that conductive mode melting and instabilities such as
balling can be captured with existing models and pave the way for models which capture the
onset of keyholing. Examination of the melt track microstructures can also be used to determine
local cooling rates, granting insight into the phase evolution differences between the alloys.",,,,,,
"['Gwynn, Daniel', 'Gundimeda, Sree Samhita', 'Menon, Nandana', 'Basak, Amrita']",2023-01-26T15:02:22Z,2023-01-26T15:02:22Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117314', 'http://dx.doi.org/10.26153/tsw/44195']",deu,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,A Computational Study Summarizing the Effects of Composition on the Melt Pool Geometry in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08d71bf5-38d0-4eea-a9bf-37be567c19f2/download,,"Thermophysical properties play a crucial role in controlling the melt pool dimensions in metal 
additive manufacturing (AM). It is, therefore, imperative to understand the impact of 
thermophysical properties on the melt pool dimensions for critical materials such as nickel-based 
superalloys. In this paper, a three-dimensional analytical model is used to predict the steady-state 
melt pool dimension over a range of process parameters for several nickel-based superalloys. The 
effects of composition, in terms of the thermophysical properties, on the melt pool dimensions are 
also studied. The results show that the melt pool dimensions correlate well with the liquidus 
temperature, density, and thermal conductivity of the alloy. By exploring the impact of process 
parameters and compositions on the melt pool dimension evolution, a framework can be 
established to maintain the desired melt pool dimensions during the fabrication of functionally-
graded parts with different alloys belonging to the same material class. ",,,,,,
"['Kelly, Brett E.', 'Bhattacharya, Indrasen', 'Shusteff, Maxim', 'Taylor, Hayden K.', 'Spaddacini, Christopher M.']",2021-11-02T20:41:27Z,2021-11-02T20:41:27Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89892,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['computed axial lithography', '3D parts', 'additive manufacturing']",Computed Axial Lithography for Rapid Volumetric 3D Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/075a1deb-26f8-43ba-ab04-0d6637aa873e/download,University of Texas at Austin,"The vast majority of additive manufacturing processes today operate by printing
voxels serially point-by-point to build up a 3D part. In some higher throughput
techniques, for example optical printing methods such as projection stereolithography [1],
[2], parts are printed layer-by-layer by curing full 2D (very thin in one dimension) layers
of the 3D part in each print step. In this work, we demonstrate a new technique which
prints entire parts all at once and eliminates layering. The approach, termed Computed
Axial Lithography (CAL), is based on tomographic reconstruction, with mathematical
optimization to generate a set of projections to optically define an arbitrary dose
distribution within a target volume and to cure the entire volume simultaneously.
Volume-at-once fabrication of complex geometries is achieved using a custom system
built from a DLP projector and a rotating resin volume. This technique can be used to
expand the range of printable geometries in additive manufacturing and relax constraints
on factors such as overhangs in topology optimization. The method also vastly increases
print speed for 3D parts. We show complex and overhanging geometries printed in situ
without layering.",,,,,,
"['Isanaka, Sriram Praneeth', 'Sridhar, Amar Bala', 'Liou, Frank', 'Newkirk, Joseph W.']",2021-09-30T18:53:13Z,2021-09-30T18:53:13Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88278', 'http://dx.doi.org/10.26153/tsw/15219']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['metal deposition', 'deposit contouring', 'coordinate measurement', '3D scanning', 'curve fitting', 'contact angle', 'ripple effect']",Computer Aided Contour Profiling of High Strength Deposits,Conference paper,https://repositories.lib.utexas.edu//bitstreams/183559fd-b5c4-464e-8364-b0ee2217acef/download,University of Texas at Austin,"Additive manufacturing processes suffer from the effect of ripples, edge rounding and
surface variations. To reduce their effect, ideal process parameters for the laser deposition
process were investigated. Also, a new method was identified to analyze deposits by accurately
plotting their contours. This was achieved through point cloud data of the deposits generated
using coordinate measurement and 3D scanning. Curve fitting was performed on the data in
Matlab to generate the contours of the deposit. The intercept values, heights, and contact angle of
the curves give an indication of the uniformity of deposits and aid in reducing defects.",,,,,,
"Crawford, Richard H.",2018-05-03T17:42:34Z,2018-05-03T17:42:34Z,1993,Mechanical Engineering,doi:10.15781/T2VM43F32,http://hdl.handle.net/2152/65046,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'SFF', 'Three Dimensional Printing', 'geometric models']","Computer Aspects of Solid Freeform Fabrication: Geometry, Process Control, and Design",Conference paper,https://repositories.lib.utexas.edu//bitstreams/ebff9bda-ddd3-400b-abdd-a807e75c64ee/download,,"Solid Freefonn Fabrication (SFF) is a class of manufacturing technologies aimed at the
production of mechanical components without part-specific tooling or process planning. Originally
used for creating modelsfor visualization, many industrial users of SFF technologies are realizing
the greater potentialofSFF as legitimate manufacturing processes for producing patterns and, in
some cases, functional.parts. Thus, SFF is becoming an important aspect of the product
realization process in these industries.
Solid Freefonn Fabrication arose from the dream of ""push-button"" prototyping, in which
solid reproductions of three-dimensional geometric models are created automatically under
computer control. Perhaps more than any other class of manufacturing technologies, computer
software development has been an integral part of the emergence of SFF. As SFF technologies
evolve toward the ability to create functional parts, computer issues gain more importance.
This paper discusses three aspects of software design for SFF: processing of geometric
data, global and local control of SFF processes, and computer-based analysis and design for SFF
manufacturing. The discussion of geometric processing issues focuses on accuracy and
completeness of input models, and the algorithms required to process such models. The interplay
between the physics of SFF processing and the desired output geometry is discussed in terms of
the development of model-based control algorithms for SFF. These two areas, geometric
processing and control, are necessary for the practical implementation of any SFF technology.
However, for SFF to realize its potential as an alternative for manufacturing functional parts,
engineers must be provided with analysis and design tools for predicting mechanical properties,
ensuring dimensional accuracy, choosing appropriate materials, selecting process parameter
values, etc. For each of these three different but related areas of software design, the state-of-theart
is assessed, contemporary research is summarized, and future needs are outlined.",,,,,,
"['Mohebi, Masoud M.', 'Yang, Shoufeng', 'Evans, Julian R. G.']",2020-03-02T15:36:48Z,2020-03-02T15:36:48Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80135', 'http://dx.doi.org/10.26153/tsw/7156']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Solid freeforming,"Computer Generation of Metal Components by Simultaneous Deposition of Mould, Cores and Part",Conference paper,https://repositories.lib.utexas.edu//bitstreams/03c936a0-e214-41da-9936-d9976d0a61f7/download,,"A new solid freeforming method based on co-delivery of mould powder materials and part
powder materials using vibration-controlled, dry powder valves is presented in this paper. Thin
layers of stainless steel powder are delivered to the forming area according to the cross-section of
the CAD file to produce the component. Mould powder which has low sinterability is delivered to
the non-forming areas of the same layer. All powders are delivered by computer-controlled,
acoustic powder valves. The flow rate and switching of the valves provides the composition and
shape control during fabrication. The stacked layers of loose powder are then sintered in a
conventional furnace. The mould materials are removed after sintering. This method avoids the
high thermal stress problem in selective laser sintering, avoids high capitalisation, makes use of
conventional furnaces and allows for the incorporation of three dimensional function gradients.
Test pieces including step wedge and Spierpinski’s cube were fabricated. Advantages, limitations
and problems are discussed.",,,,,,
"['Wang, Jia-Chang', 'Wang, Jun-Ming', 'Lin, Tsung Te', 'Jeng, Jeng-Ywan']",2019-10-18T16:00:33Z,2019-10-18T16:00:33Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76244', 'http://dx.doi.org/10.26153/tsw/3333']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Adaptive Slicing,Computer Integrated Adaptive Slicing and Vision Technologies for High Performance Rapid Prototyping System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/26e08cf1-98fe-4e8e-92ec-f3add531fcf6/download,,"This paper discusses the application of adaptive slicing algorithm and computer vision technology on Rapid Prototyping (RP) system to enhance fabrication performance of Model Maker (MM) RP system. Usually, the layer number determines the RP system performance in terms of fabrication time and accuracy. In this research, a new practically adaptive slicing algorithm is developed and easily implemented for RP system, because it only recalculates the scanning path according to the criterion of adjacent profile variation. The experimental results of the proposed adaptive slicing algorithm show that saving of 54% fabrication time is achieved and the model accuracy is still remained in the same level. MM presents a problem of stability because of a tiny nozzle. Computer vision technology is employed in this paper to on line inspect the layer accuracy and defect of a model fabricated by RP system. The results of vision inspection is used to close-loop monitor the process to increase the processing stability and accuracy. These new practically adaptive slicing algorithm and machine vision technology are implemented in the commercial Model Maker (MM) RP system to increase its fabrication speed, accuracy and stability, but not accuracy sacrifice. Hence, the performance of the MM RP system can be significantly enhanced using vision and practically adaptive slicing techniques.","The support of this research by the National Science Council of Taiwan, ROC under grant NSC-88-2212-E-011-026.",,,,,
"['Reiher, T.', 'Vogelsang, S.', 'Koch, R.']",2021-11-02T20:34:53Z,2021-11-02T20:34:53Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89890,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['geometry generation', 'computer integration', 'CAD system', 'optimization', 'additive manufacturing']",Computer Integration for Geometry Generation for Product Optimization with Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/477f6543-9156-4506-9288-f0647892bc53/download,University of Texas at Austin,"Designing parts for additive manufacturing (AM) offers a broad range of geometrical and
functional potentials. On the one hand the manufacturing technology offers the possibility of
manufacturing highly complex freeform shapes, often referred to as bionic shapes. By use of these,
perfect force fluxes without stress risings due to imperfect notches are realizable, getting the most
value of used material. On the other hand these complex structures require a reliable geometry
representation in compatible CAD-files. Conventional CAD systems were developed to generate
geometries that are manufacturable with conventional machining. These are not capable of
representing the high complex designs for AM. Especially for geometries generated by CAE like
from topology optimization the conventional CAD systems fail to take advantage of the
combination of CAE and AM.
This paper explains why there is a lack of compatibility of well-known CAD systems with the
potentials of AM. Therefore the AM-side of the problem is described by showing some potentials
of AM and the need of high complex structures for this manufacturing technology. For the other
side of the problem conventional methodologies for geometry representation of CAD systems are
described and their limitations with regard to AM are worked out. Finally a voxel based geometry
representation is presented as a solution for computer aided geometry generation of high complex
AM–structures.",,,,,,
"['Flach, Lawrance', 'Chartoff, Richard P.']",2018-04-12T17:18:53Z,2018-04-12T17:18:53Z,1990,Mechanical Engineering,doi:10.15781/T2MC8S000,http://hdl.handle.net/2152/64268,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical and Materials Engineering', 'Rapid Prototype Development Laboratory', 'Center for Basic and Applied Polymer Research']",A Computer Model for Laser Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ec0f045-a8a1-49c2-93b0-13c4008a984a/download,,"A computer model for a laser induced photopolymerization process has been established
which simulates stereolithography. The model couples irradiation, chemical reaction, and heat
transfer equations to provide insights into rate processes occurring in the volume element
contacted by the laser beam. Quantities predicted include the spatial variation in conversion of
monomer to polymer, depletion of photoinitiator, and local variations in temperature in and
around the spot contacted by the laser. This allows predictions to be made about the laser dwell
time, depth penetration and uniformity of the photopolymer formed in the process.",,,,,,
"['Bernard, Alain', 'Davillerd, Stephane', 'Sidot, Benoit']",2019-03-11T16:49:23Z,2019-03-11T16:49:23Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73584', 'http://dx.doi.org/10.26153/tsw/726']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['CAD', '3D-laser sensor']",Computer-Aided Process Planning for automatic generation of 3D digitizing process for laser sensors,Conference paper,https://repositories.lib.utexas.edu//bitstreams/caaad483-ba71-4ddd-aa85-24790db64965/download,,"This paper introduces some results of a research work carried out on the automation of digitization
process ofcomplex parts using a precision 3D-laser sensor.
It will be presented a new way to scan automatically a complex 3-D part in order to measure and to
compare the acquired data with the reference CAD model. Due to the fact that rapid prototyping
processes do not allow the direct manufacturing of high precision parts, it is very often necessary to
measure a first partin orderto modify the process parameters.
After introducing the digitization means, basedona CMM machine and a plane laser sensor, the
simulation environment will be presented as adapted for simulation and validation of 3D-laser scanning
paths. The CAPP (Computer Aided Process Planning) system used for the automatic generation·of the
laser scanning process will also be introduced.
Keywords: scanning process simulation, inspection, optimization",,,,,,
"['Xiong, Yi', 'Dharmawan, Audelia Gumarus', 'Tang, Yunlong']",2021-11-18T16:46:36Z,2021-11-18T16:46:36Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90423', 'http://dx.doi.org/10.26153/tsw/17344']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['process planning', 'directed energy deposition', 'knowledge-based engineering', 'design for additive manufacturing']",Computer-Aided Process Planning for Wire Arc Directed Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13ca29d4-c582-4d6a-8478-a441fb7027c9/download,University of Texas at Austin,"Wire arc directed energy deposition provides a rapid and cost-effective method for fabricating
low-to-medium complexity and medium-to-large size metal parts. However, the complex
nonequilibrium phase transformations, inherent to this process, make it a challenging task to
produce consistent and high-quality parts, especially for parts with materials or geometries that
have not been manufactured before. This study outlines a holistic and data-centric computer-aided process planning framework utilizing a knowledge base to assist engineers in selecting
optimal process parameters that reduce dimensional deviations, and therefore to obtain near-net-shape parts using directed energy deposition only. The knowledge base has a data-knowledge-service architecture and is proposed to synthesize information from various sources,
e.g., characterization tests. Based on these collected data, several knowledge representations,
including database, metamodels, and planning rules, are constructed to support decision-making in the process planning. The proposed framework is demonstrated in the fabrication of
components from industrial applications.",,,,,,
"['Cima, M.J.', 'Sachs, E.', 'Cima, L.G.', 'Yoo, J.', 'Khanuja, S.', 'Borland, S.W.', 'Wu, B.', 'Giordano, R.A.']",2018-10-03T15:25:24Z,2018-10-03T15:25:24Z,1994,Mechanical Engineering,doi:10.15781/T2959CS8Q,http://hdl.handle.net/2152/68644,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Microstructures', '3D Printing', 'Solid free-form fabrication']",Computer-derived microstructures by 3D Printing: Sio- and Structural Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d9cbed21-790b-4677-8490-1af1aa108dcf/download,,"3D Plinting is a rapid prototyping technique to manufacture functional components
directly from computer models. The process involves spreading the powder in thin layers
and then selective binding of the powder using a technology similar to ink-jet ptinting.
Layers are added sequentially until a part is completed. 3DP has been used to make
complex-shaped components from several monolithic matetials, including cOlnponents for
use in structural applications. This paper focuses, however, on the ability to control
microstlucture and local composition by 3DP. We envision cases where cOlnputer
delived-microstructlu'es can be created by approptiate control of the ptinting paralneters.
Thus, one can build components with the desired microstlucture independent of the
complexity of the desired shape. Examples for both structural matetials and biomedical
devices are discussed.",,,,,,
"Thompson, Scott M.",2021-11-16T15:43:56Z,2021-11-16T15:43:56Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90319', 'http://dx.doi.org/10.26153/tsw/17240']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['design for additive manufacturing', 'education', 'training', 'conceptual design']",Conceptual Design for Additive Manufacturing: Lessons Learned from an Undergraduate Course,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c58786fc-f646-4e80-b22d-81c2bc03dd70/download,University of Texas at Austin,"Design for additive manufacturing (DfAM) guidelines continue to emerge and evolve as various
additive manufacturing (AM) technologies, and the knowledge of their associated end-users/designers, matures. This work summarize important pedagogical and technical lessons
learned from the conceptual re-design of several, diverse parts/assemblies submitted by ~50
undergraduate students cognizant of recent DfAM strategies and guidelines. All students were
enrolled in a traditional, semester-long metals AM course designed by the author herein. Students
were instructed to select an existing, metallic product and provide a conceptual redesign of that
product for subsequent, effective laser-powder bed fusion (L-PBF). Students were instructed that
the redesigned concept should have enhanced functionality/specifications and consist of features
(e.g. thin walls, bore diameters, etc.) that can be fabricated with minimal risk via current L-PBF
systems. The presented results include the types of parts that attract an ‘AM redesign’ effort and
the most popular AM-enabled detailed design decisions made. To encourage a more detail-inspired design, DfAM topics were presented ‘backwards’; from post-manufacturing
considerations to conceptual design while considering emerging design rules and heuristics.
Results indicate that students can become preoccupied with DfAM rules to a point where the
design failure modes are not properly accounted for.",,,,,,
"['Yang, S.', 'Zhao, Y.F.']",2021-11-01T20:42:42Z,2021-11-01T20:42:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89740,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['assembly-level DFAM', 'conceptual design', 'additive manufacturing', 'functional design', 'FBS modeling']",Conceptual Design for Assembly in the Context of Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e552f158-8b8b-44ac-aa73-92636b7d935a/download,University of Texas at Austin,"As additive manufacturing (AM) emerges as an end-of-use product manufacturing process,
design for additive manufacturing (DFAM) as a new design philosophy receives more and more
attention. However, current DFAM research focuses on downstream and part-level design
activities such as structural optimization and design rules. Design freedom enabled by AM such
as, part consolidation and function integration has not been fully investigated. These design
freedom forces designers to rethink about assembly-level design so as to embrace integrated
functionality. To understand how to integrate AM characteristics into design process, three
questions are investigated: 1) why does conceptual design need to be redone for assembly? 2) what
has changed by AM in design concept generation? 3) how to do conceptual design in AM context?
Afterwards, a conceptual design framework is proposed to aid design flow management. In the
end, a throttle pedal redesign case is demonstrated as verification of the proposed design
framework.",,,,,,
"['Gobert, Christian', 'Arrieta, Edel', 'Belmontes, Adrian', 'Wicker, Ryan B.', 'Medina, Francisco', 'McWilliams, Brandon']",2021-11-16T16:12:15Z,2021-11-16T16:12:15Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90329', 'http://dx.doi.org/10.26153/tsw/17250']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['machine learning', 'additive manufacturing', 'conditional generative adversarial networks', 'in-situ monitoring']",Conditional Generative Adversarial Networks for In-Situ Layerwise Additive Manufacturing Data,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2948b08-58a6-490a-a826-bb4a20d9f4d0/download,University of Texas at Austin,"Conditional generative adversarial networks (CGANs) learn a mapping from conditional input to
observed image and perform tasks in image generation, manipulation and translation. In-situ
monitoring uses sensors to obtain real-time information of additive manufacturing (AM) processes
that relate to process stability and part quality. Understanding the correlations between process
inputs and in-situ process signatures through machine learning can enable experimental-driven
predictions of future process inputs. In this research, in-situ data obtained during a metallic powder
bed fusion AM process is mapped with a CGAN. A single build of two turbine blades is monitored
using EOSTATE Exposure OT, a near-infrared optical tomography system of the EOS M290
system. Layerwise images generated from the in-situ monitoring system were paired with a
conditional image that labeled the specimen cross-section, laser-scan stripe overlap and z-distance
to part surfaces. A CGAN was trained using the turbine blade data set and employed to generate
new in-situ layerwise images for unseen conditional inputs.",,,,,,
"['Gibbons, D.W.', 'Ko, H.']",2021-12-01T22:13:55Z,2021-12-01T22:13:55Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90635', 'http://dx.doi.org/10.26153/tsw/17554']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['configuration control', 'additive manufacturing', 'digital twins']",Configuration Control for Additive Manufacturing Digital Twins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e8d0dd2-ea51-4d00-8ecf-938161d2a135/download,University of Texas at Austin,"The additive manufacturing workflow is a ductile entity, often varying depending on the design,
the product, the process, the material, and the application. Information models and schemas have been
developed that can provide structure to data and information throughout the workflow. The result has been a
well-characterized outline of an additive manufacturing digital thread. However, implementation-specific
details are often missing from these characterizations, creating challenges in establishing part-specific
workflows necessary for product configuration control and management. While software vendors are
increasingly filling this gap, a software-agnostic workflow is yet to be defined. This paper investigates
the additive manufacturing workflow and establishes the fundamentals of a standardized,
configuration-control approach including formats and interoperability while addressing versioning, digital
rights, and ownership.",,,,,,
"['Hopkinson, Neil', 'Dickens, Phill']",2019-09-23T17:09:49Z,2019-09-23T17:09:49Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75976', 'http://dx.doi.org/10.26153/tsw/3075']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Sintered,Conformal Cooling and Heating Channels using Laser Sintered Tools 490,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6771c526-9d82-4307-be58-022cd63dcfd9/download,,"The EOS Direct Metal Laser Sintering (DMLS) and DTM Rapid Steel 2 processes may be used to create tools incorporating conformal channels behind the tool surface through which fluids may be passed. To date, a significant amount of work has been carried out to investigate the efficiency of using conformal channels to cool tools. This work suggests the use of conformal channels to both cool and heat a single tool. This may appear self-defeating at first but the selective nature by which conformal channels may make this a worthwhile means of generating hitherto unavailable thermal conditions within a tool. Such conditions may then allow the successful production of geometries which had previously been impossible to mould.",,,,,,
"['Nguyen, Jason', 'Park, Sang-In', 'Rosen, David W.', 'Folgar, Luis', 'Williams, James']",2021-10-05T15:58:51Z,2021-10-05T15:58:51Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88400', 'http://dx.doi.org/10.26153/tsw/15339']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Conformal Lattice Structures', 'computer-aided design', 'stress distributions', 'heuristic', 'Micro Air Vehicle']",Conformal Lattice Structure Design and Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/446e81f5-c1a0-4631-af72-897a0d6cf767/download,University of Texas at Austin,"One application of additive manufacturing is for fabrication of customized, light-weight material
called Conformal Lattice Structures (CLS), a type of cellular structure with dimensions of 0.1 to 10
mm. In this paper, two advances are reported for designing CLS. First, computer-aided design
technologies were developed for efficiently generating and representing CLS, given selected part
model surfaces. Second, a method is presented for efficiently optimizing CLS by utilizing a
heuristic that reduces the multivariate optimization problem to a problem of only two variables.
The heuristic is: stress distributions are similar in CLS and in a solid body of the same shape.
Software will be presented that embodies this process and is integrated into a commercial CAD
system. In this paper, the method is applied to design strong, stiff, and light-weight Micro Air
Vehicle (MAV) components.",,,,,,
"['Hayasi, Mohammad', 'Asisbanpour, Bahram']",2021-10-06T21:12:35Z,2021-10-06T21:12:35Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88445', 'http://dx.doi.org/10.26153/tsw/15382']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['sloped-edge adaptive slicing', '5-axis cutting', 'rapid functional part fabrication', 'rapid tooling', 'fully dense freeform fabrication (FDFF)']",Conformed-to-CAD Design Sloped-Edge Adaptive Splicing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d50a515a-c02d-4fc8-8781-6a4c81d8e943/download,University of Texas at Austin,"Many mathematical and simulation based researches have shown the effectiveness of
adaptive and angular slicing and layering in minimizing errors in layered manufacturing
processes and improving surface quality and build time. Recent technological advances such as
5-axis laser cutters, abrasive waterjets, and CNC machines have enabled physical part fabrication
beyond typical vertical layered manufacturing with staircase errors. In this paper, a new curvedform adaptive slicing method is presented. In this method, multiple cuts of the edge boundary of
each adaptive layer with variable cutting vector angles conform well to CAD model curved
surfaces. The proposed system is compatible with 5-axis abrasive waterjet machines. This system
has been successfully tested on several virtual 3D CAD models.",,,,,,
"['Kigure, T.', 'Yamauchi, Y.', 'Ninno, T.']",2024-03-25T22:22:01Z,2024-03-25T22:22:01Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124319', 'https://doi.org/10.26153/tsw/50927']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PEEK', 'laser sintering', 'temperature', 'additive manufacturing']",Considerations of internal void generation process by observation of melting and solidification behavior in low temperature laser sintering of PEEK,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6d880f5e-d1ca-48cb-a2f6-097bedbc2d33/download,University of Texas at Austin,"Laser sintering of PEEK performed below the crystallization temperature has been achieved in
previous study by low temperature process that anchors the part to a rigid base plate to suppress
warpage during processing. However, significant surface roughness and large internal voids are
sometimes generated in the parts built by low temperature process, and there are problems in
stability of parts quality. The purpose of this study is to contribute to quality improvement of
laser sintering of PEEK by low temperature process. It was attempted that clarify the process of
surface roughness and void generation by observing the melting and solidification behavior of
the material during process with a video camera. From these observation results, it was assumed
that the amount of volume change from powder to liquid due to melting and the amount of
shrinkage due to solidification affect part quality such as surface roughness and internal voids.",,,,,,
"['Schumacher, Christian', 'Schöppner, Volker', 'Guntermann, Jonas']",2021-11-02T17:50:01Z,2021-11-02T17:50:01Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89837,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['machine-specific influence', 'process-specific influence', 'custom-built', 'fused deposition modeling']",Considering Machine- and Process-Specific Influences to Create Custom-Built Specimens for the Fused Deposition Modeling Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53b73205-c410-49f7-9e9b-edd065fb0eaa/download,University of Texas at Austin,"Compared to conventional polymer processing technologies the material selection in the
Fused Deposition Modelling (FDM) process is restricted. To expand the range of materials the
requirements for the material properties and the semi-finished products (filaments) must be
clarified. For this, a machine- and process-independent rating of the processability is necessary.
The established standards for the tensile strength test apply to specimens with nearly isotropic
mechanical properties. The FDM process generates anisotropic parts. The properties are mainly
influenced by the machine quality and the data processing. It is not possible to test a material for
FDM independently of the machine and the data processing. In this paper, machine and process-specific influences are investigated. Considering these influences, a custom-built specimen is
created to test the tensile strength of the welding seams for polyamide 6. This procedure allows a
machine- and process-independent rating of the processability in terms of tensile strength for
different materials.",,,,,,
"['Khoshnevis, Behrokh', 'Yuan, Xiao', 'Zahiri, Behnam', 'Xia, Bin']",2021-10-21T22:02:09Z,2021-10-21T22:02:09Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89455,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Contour Crafting', 'sulfur concrete', 'planetary']",Construction by Contour Crafting Using Sulfur Concrete with Planetary Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/312e1f1d-0866-4842-9134-159c8902fc33/download,University of Texas at Austin,"This paper reports on the experiments with the Contour Crafting Automated Construction process using
sulfur concrete as the choice of construction material. Sulfur concrete has numerous terrestrial applications and
is potentially an ideal construction material for planetary construction. On Mars, sulfur can be found in
abundance and the range of temperature variation on the planet is within the safe zone for the structures to be
built and survive over reasonable length of time with sulfur concrete. Several experiments have been performed
at centimeter and meter scales. A FEA simulation model for the behavior of sulfur concrete based structures
has been developed. Experimental results were compared with the results of simulation.",,,,,,
"['Shen, Yiju', 'Li, Yingqi', 'Tsai, Hai-Lung']",2021-11-02T19:42:52Z,2021-11-02T19:42:52Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89878,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['metallic glass', 'laser-foil-printing', 'amorphous foils', 'foils', 'additive manufacturing']",Construction of Metallic Glass Structures by Laser-Foil-Printing Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/324f4cea-abc3-49b4-9d49-cadff220bd28/download,University of Texas at Austin,"Metallic glasses (MGs) have superior mechanical properties such as high tensile strength,
hardness, and corrosion resistance, as compared to crystalline metals. Although newly developed
MGs have significantly reduced critical cooling rates down to 10 K/s, products of MGs are still
limited to simple geometries such as foils/plates or rods with thin section-thickness which is
mainly caused by the decrease of thermal conductivities of the new MGs. Recently, we developed
a new Laser-foil-printing (LFP) additive manufacturing technology which welds foils, layer by
layer, to construct desired 3D structures. With the LFP and Zr-based amorphous foils, 3D, large
amorphous structures with complex geometry have been successfully manufactured. To better
understand the evolution of crystalline phase, we integrate the finite element based heat transfer
model and classic nucleation theory (CNT) based crystal nucleation/growth model. The model was
used to demonstrate the evolution of crystal phase as a function of time during laser welding at
different locations including the fusion zone (FZ) and heat-affected zone (HAZ). The model is also
compared favorably with the experiment results. The reported susceptibility to crystallization in
HAZ were discussed and explained.",,,,,,
"['Lawrence, Jacob', 'Peña Vega, Hector Andres', 'Stegman, Bryant', 'Roberts, Caleb', 'Spencer, Joseph', 'James, Clinton', 'Christensen, McKay', 'Crane, Nathan']",2023-01-31T13:52:42Z,2023-01-31T13:52:42Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117366', 'http://dx.doi.org/10.26153/tsw/44247']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Binder jetting,Construction of Open-Source Laboratory-Scale Binder Jetting System for High-Speed Synchrotron X-Ray Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4bf55d2-8f94-4994-a64b-db93293cd0ca/download,,"Although commercial binder jetting (BJ) printers are available, they typically do not allow 
sufficient control over process parameters needed to study fundamental process characteristics. 
This work presents an overview of the design and construction of a custom BJ system used to 
observe fundamental phenomena in the BJ process. CAD models for the design and information 
on the software of this system is also given.  This system will help elucidate the mechanisms that 
introduce part defects and other challenges unique to the BJ process. The BJ system was designed 
for both laboratory-scale experiments with a 100 x 100 mm build box and high-speed synchrotron 
X-ray imaging with a 500 μm thick powder bed, requiring high-accuracy motion stages and a 
controller with precise timing. The printer includes functionality for depositing and rolling powder, 
printing multi-layer parts, and direct observation of the jetting nozzle. This BJ system has enabled 
experiments that provide insight into the printing process that will aid future efforts to mitigate 
challenges associated with BJ.",,,,,,
"['Lawrence, Jacob', 'Peña Vega, Hector Andres', 'Stegman, Bryant', 'Roberts, Caleb', 'Spencer, Joseph', 'James, Clinton', 'Christensen, McKay', 'Crane, Nathan']",2023-01-27T18:04:50Z,2023-01-27T18:04:50Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117352', 'http://dx.doi.org/10.26153/tsw/44233']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Binder jetting,Construction of Open-Source Laboratory-Scale Binder Jetting System for High-Speed Synchrotron X-Ray Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69e75d53-cecd-4a1c-86f3-852e31c88878/download,,"Although commercial binder jetting (BJ) printers are available, they typically do not allow 
sufficient control over process parameters needed to study fundamental process characteristics. 
This work presents an overview of the design and construction of a custom BJ system used to 
observe fundamental phenomena in the BJ process. CAD models for the design and information 
on the software of this system is also given.  This system will help elucidate the mechanisms that 
introduce part defects and other challenges unique to the BJ process. The BJ system was designed 
for both laboratory-scale experiments with a 100 x 100 mm build box and high-speed synchrotron 
X-ray imaging with a 500 μm thick powder bed, requiring high-accuracy motion stages and a 
controller with precise timing. The printer includes functionality for depositing and rolling powder, 
printing multi-layer parts, and direct observation of the jetting nozzle. This BJ system has enabled 
experiments that provide insight into the printing process that will aid future efforts to mitigate 
challenges associated with BJ.",,,,,,
"['Hoglund, R.', 'Smith, D.E.']",2021-10-28T14:53:59Z,2021-10-28T14:53:59Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89657,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['topology optimiation', 'continuous fiber angle optimization', 'fused filament fabrication']",Continuous Fiber Angle Topology Optimization for Polymer Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de984a93-2713-4dab-9ae9-2f1b8de6f70b/download,University of Texas at Austin,"Mechanical properties of parts produced with the Fused Filament Fabrication (FFF) process are
known to be dependent on the printed bead direction, especially when short carbon fiber
reinforcement is added to the filament. Given that many FFF filament suppliers now offer
carbon-fiber filled products, a unique opportunity emerges in the design of polymer composite
FFF parts since bead and fiber direction can potentially be prescribed to give the best structural
performance. As FFF moves from a technology for rapid prototyping and the hobbyist to a viable
additive manufacturing method, it is important to also have a design tool that takes advantage of
the opportunities that present themselves when polymer composites are employed. This paper
presents a topology optimization method for continuous fiber angle optimization approach
(CFAO), which computes optimal material distribution (as in the well known SIMP method) in
addition to a preferred fiber angle direction by minimizing compliance of statically loaded
structures. Our computed results show the effects of variable orientation angle on fiber
reinforced microstructure for the topology of two-dimensional FFF parts. Optimal fiber
orientations are shown to align with the axis of structural members that form within the structure
as expected. Example design problems are solved and then printed on desktop 3D FFF printers
using the material distribution results and a simple infill method which approximates the optimal
fiber angle results by a contour-parallel deposition strategy. Mechanical stiffness testing of the
printed parts show improved results as compared to structures designed without accounting for
the direction of the composite structure. Future work includes extension of the method to three
dimensional structures for further application.",,,,,,
"['Mei, Junfeng', 'Lovell, Michael', 'Mickle, Marlin', 'Heston, Steve']",2020-02-13T20:44:18Z,2020-02-13T20:44:18Z,9/1/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79975', 'http://dx.doi.org/10.26153/tsw/7000']",eng,2004 International Solid Freeform Fabrication Symposium,Open,photolithography,Continuous ink-jet printing electronic components using novel conductive inks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/72de18f3-16ae-434c-b0dd-94b6d166cdca/download,,"To reduce the cost of electronics fabrication and to take advantage of numerous potential
specialized applications, a novel process of manufacturing three-dimensional electronic products
is introduced in the present investigation. This process, which is currently being patented by the
University of Pittsburgh, utilizes specialized continuous ink jet (CIJ) printing technology and
innovative conductive inks that are capable of producing high-resolution conductive traces.
Unlike drop-on-demand (DOD) techniques that are aimed at more precise features sizes (1
micron or less) and smaller scale applications, the present investigation demonstrates that the
new process can be used in mass production applications where larger feature sizes (~50
microns) are sufficient. It has been found that the traces produced by the process have excellent
adherence and have an electrical resistivity of only 2.9 times of bulk silver after curing. The
major advantage of the proposed CIJ process is that it not only provides a fast and cost-effective
method for applying electronic components (conductors, diodes, capacitors and resistors) on
existing products, but it also allows the printing of conductive traces in three-dimensional space.
With a throw distance that exceeds 10 cm, it demonstrates how the new fabrication process is not
only suitable for desktop microfabrication, but also for large volume applications such as automotive glass.",,,,,,
"['Yeung, H.', 'Lane, B.', 'Fox, J.', 'Kim, F.', 'Heigel, J.', 'Neira, J.']",2021-11-03T22:39:47Z,2021-11-03T22:39:47Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89953,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['continuous laser scan', 'build speed', 'laser powder bed fusion', 'National Institute Standards and Technology', 'NIST']",Continuous Laser Scan Strategy for Faster Build Speeds in Laser Powder Bed Fusion System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cde24878-27fc-41ea-a6be-131544f49b50/download,University of Texas at Austin,"Research has shown significant influence of laser scan strategy on various part qualities in the laser
powder bed fusion additive manufacturing process. The National Institute of Standards and Technology
developed the Additive Manufacturing Metrology Testbed, which provides open architecture for flexible
control and monitoring during a laser powder bed fusion additive manufacturing process. This allows
extended control of scan strategies, including control of laser power and speed within each scan line. A
‘continuous’ scan strategy can reduce build times and improve throughput by negating the need to turn the
laser off between scan tracks (e.g., sky-writing). Also, less frequent laser power interruption can potentially
improve the melt-pool continuity. Multiple experiments are performed utilizing the continuous and
traditional scan strategies, and comparisons are made between build time and measured melt-pool qualities.",,,,,,
"['Altenhofen, C.', 'Luu, T.H.', 'Grasser, T.', 'Dennstädt, M.', 'Mueller-Roemer, J.S.', 'Weber, D.', 'Stork, A.']",2021-11-11T16:32:25Z,2021-11-11T16:32:25Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90238', 'http://dx.doi.org/10.26153/tsw/17159']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['material gradients', 'property gradadtion', 'multi-materials', '3D printing']",Continuous Property Gradation for Multi-Material 3D-Printed Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8580c856-99cd-4fe5-b48f-e6b717de3b1e/download,University of Texas at Austin,"Modern AM processes allow for printing multiple materials. The resulting objects can be
stiff/dense in some areas and soft/porous in others, resulting in distinct physical properties. However, modeling material gradients is still tedious with current approaches, especially when smooth
transitions are required. Current approaches can be distinguished into a) NURBS-BReps-based
and b) voxel-based. In case of NURBS-BReps, discrete material distributions can be modeled
by manually introducing separate shells inside the object; smooth gradation can only be approximated in discrete steps. For voxel representations, gradation is discrete by design and comes
along with an approximation error. In addition, interacting on a per-voxel basis is tedious for the
designer/engineer. We present a novel approach for representing material gradients in volumetric
models using subdivision schemes, supporting continuity and providing elegant ways for interactive modeling of locally varying properties. Additionally, the continuous volumetric representation
allows for on-demand sampling at any resolution required by the 3D printer.",,,,,,
"['Dwivedi, Rajeev', 'Dwivedi, Indira', 'Dwivedi, Bharat']",2023-01-27T17:44:08Z,2023-01-27T17:44:08Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117344', 'http://dx.doi.org/10.26153/tsw/44225']",eng,2022 International Solid Freeform Fabrication Symposium,Open,staircase effect,Continuous Sculpting as a Novel Method to Reduce the Staircase Effect in Solidfreeform Fabrication Processes that  Are Dependent on Phase Transformation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1a187172-12f1-482b-b3df-c886047f35b4/download,,"Inherent to 2-1/2 axis deposition in Solid Freeform Fabrication is Staircase effect. The surface geometry 
of parts produced using Solid Freeform Fabrication, therefore is not smooth. Continuous sculpting is a 
novel method that combines additive manufacturing to surface modification by relative motion of a 
forming tool. Molten material is added to substrate. A forming tool that can tilt along different axes is 
connected to the end effector. The forming tool is oriented along a desired angle and then applies force 
on the molten material to give it desired 
shape on the fly. This paper introduces the novel method and a simple case studies.",,,,,,
"['Wu, Ying-Jeng Engin', 'Beaman, J.J.']",2018-04-10T19:15:04Z,2018-04-10T19:15:04Z,1990,Mechanical Engineering,doi:10.15781/T2T14V62C,http://hdl.handle.net/2152/64249,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['geometric contour', 'SFF application', 'speed']",Contour Following for Scanning Control in SFF Application : Control Trajectory Planning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7fb9c2b7-5ae9-4f9e-aadb-e1ba74cf6cec/download,,"Geometric contour following for scanning control in SFF application is used to
refine the boundary ofthe parts for increasing the accuracy or to develop the capability to
arrange various scanning directions and paths for improving the part strength. The scanners
must be driven to follow the prescribed path as fast as possible, limited by available
torques. In this paper the minimum time optimal control problem with specified path and
limited control torque is formulated. According to the trade-off between various
requirements, a control strategy is studied.",,,,,,
"['Tse, L.Y.L.', 'Kapila, S.', 'Barton, K.']",2021-10-28T15:45:51Z,2021-10-28T15:45:51Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89667,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fiber reinforced polymers', 'additive manufacturing', 'contoured 3D printing', '3D printing']",Contoured 3D Printing of Fiber Reinforced Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a74a686d-3bc4-471a-958b-dd4939ad0818/download,University of Texas at Austin,"Additive manufacturing (AM) is a cost effective approach for small-scale production,
providing higher design flexibility and less material waste than traditional manufacturing
techniques. Polymers constitute one of the most popular AM materials, yielding lightweight but
inherently weak components that cannot hold up against high tension and bending stresses. A need
for improved tensile strength has driven a recent interest in AM of fiber reinforced polymers
(FRPs). AM-FRPs reinforced with short fibers have demonstrated increased mechanical strength,
but with limited design and structural flexibility. AM-FRPs reinforced with continuous fibers
provide structural reinforcement within plane; as such, the fibers cannot be extruded along a
contoured profile, significantly minimizing the application space for these AM-FRP devices. In
this article, we address this current gap through the development of a new FRP additive
manufacturing process that is capable of continuous fiber deposition along contoured trajectories.
Experimental demonstrations validate the proposed process.",,,,,,
"['Seufzer, W. J.', 'Taminger, K. M.']",2020-03-09T13:16:09Z,2020-03-09T13:16:09Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80171', 'http://dx.doi.org/10.26153/tsw/7190']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Electron Beam Free Form Fabrication,Control Methods for the Electron Beam Free Form Fabrication Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8542016b-f8b5-45a9-a934-7f8601b77574/download,,"Engineering a closed-loop control system for an electron beam welder for additive
manufacturing is challenging. For earth and space based applications, components must work in
a vacuum and optical components must be protected from becoming occluded with metal vapor.
For extraterrestrial applications added components increase launch weight and increase
complexity. Here we present three different control methods for electron beam free form
fabrication. A relatively simple coarse feedback control method is introduced that couples path
planning and electron beam parameter controls into the build process to increase flexibility and
improve build quality. The different approaches may be applied separately or together to provide
enhanced EBF3 system performance.",,,,,,
"['Boddu, Mallikharjuna R.', 'Landers, Robert G.', 'Liou, Frank W.']",2019-10-18T16:19:50Z,2019-10-18T16:19:50Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76251', 'http://dx.doi.org/10.26153/tsw/3340']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Laser Cladding,Control of Laser Cladding for Rapid Prototyping--a Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/70109e14-caa4-45bf-8995-d0b4fac574f2/download,,"Lasers have wide–ranging applications in the manufacturing field (e.g., cladding,
welding, cutting, machining, drilling). Extensive work is being conducted to apply laser cladding
as a Rapid Prototyping (RP) process. In this paper the authors illustrate various principles of
laser cladding in rapid prototyping. Important process parameters for the control of the laser
cladding process are discussed as well as the experimental methods adopted, and results obtained
by, various authors.",,,,,,
"['Chin, R.K.', 'Beuth, J.L', 'Amon, C.H.']",2018-11-02T14:15:36Z,2018-11-02T14:15:36Z,1995,Mechanical Engineering,doi:10.15781/T2PG1J73P,http://hdl.handle.net/2152/69329,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Shape Deposition Manufacturing', 'carbon steel', 'inelastic compression-tension']",Control of Residual Thermal Stresses in Shape Deposition Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a8ca57b1-c209-4e55-a861-2dd9dd7b8e31/download,,"Layer-level thermal and mechanical modeling ofthe microcasting stage of ShaPe Deposition
Manufacturing is presented. Thermo-mechanical models of carbon steel deposited onto a carbon
steel substrate are described. Mechanics modeling addresses the issue of residual stress build-up.
The effects of substrate heating and bending constraint on the build-up of residual stresses are
shown. Results show that thermal cycling from newly applied droplets drastically changes the
stress state in the top of the substrate. Originally unstressed regions go through an inelastic
compression-tension stress cycle. Residual stresses reach values that may cause yielding in carbon
steel. Moderate heating of the substrate above room temperature prior to droplet deposition
reduces stresses significantly. Bending constraint during part manufacture allows partial relaxation
of stresses as the constraint is removed.",,,,,,
"['Yang, Feifei', 'Jiang, Tianyu', 'Chen, Xu', 'Lalier, Greg', 'Bartolone, John']",2021-12-01T23:50:07Z,2021-12-01T23:50:07Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90663', 'http://dx.doi.org/10.26153/tsw/17582']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'surface quality', 'polyamide 12', 'additive manufacturing']",A Control of Surface Quality in Selective Laser Sintering Additive Manufacturing with Reclaimed Polyamide Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a47d471-d13e-4d87-af94-bfd7ef098d30/download,University of Texas at Austin,"In selective laser sintering (SLS) additive manufacturing (AM), a substantial amount of
polyamide 12 materials remains un-sintered, recyclable, and reusable. However, using reclaimed
polyamide 12 powder in SLS results in undesirable part surface finish. Very limited research has
been done on the improvement of part surface quality and results barely exist on improving or
modifying the surface quality of parts using extremely aged powders (powders held close to the
heat-affected zones). Aiming to improve the surface quality, we propose a novel approach for
SLS with (extremely) aged polyamide 12 powders. By combining material preparation, powder
and part characterizations, and SLS with a customized method of post-heating, we obtain parts
with improved surface quality (e.g., reduced roughness and porosities, and eliminated un-sintered particles). Particularly, parts 3D-printed using the 30%-30%-40% new-aged-extremely
aged mixed powders exhibit the smoothest and flattest surface with no unmolten particles and
nearly zero porosity.",,,,,,
"['Wang, Jiwen', 'Shaw, Leon L.', 'Marcus, Harris L.', 'Cameron, T.B.']",2019-11-21T17:48:04Z,2019-11-21T17:48:04Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78543', 'http://dx.doi.org/10.26153/tsw/5599']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Cross Section,Control of the Cross Section Geometry of Extruded Dental Porcelain Slurries for Rapid Prototyping Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/06ad576b-bf4e-4b46-a1d5-3aa01017c6a8/download,,"This study investigates the dependence of the cross section geometry of extruded dental
porcelain slurries on the rheological property of the slurry and the extrusion conditions. It is
found that a pseudoplastic slurry is a basic requirement for obtaining extruded lines with
rectangular cross sections. The cross section geometry of the extrudate is also strongly affected
by extrusion parameters including the extrusion nozzle height, nozzle moving speed, and
extrusion rate. Proper combinations of these extrusion parameters are necessary in order to
obtain extrudates with near rectangular cross sections. The results obtained have been explained
in terms of the interactions among the rheological properties of the slurry, the shear rate imposed
on the slurry during extrusion, the wettability of the slurry on the substrate, and the forced flow
of the slurry during extrusion.","The authors gratefully acknowledge financial support provided by
the National Science Foundation under Grant Nos: DMI-9908249 and DMI-0218169.",,,,,
"['Capps, Nicholas', 'Goldstein, Jonathan', 'Landers, Robert', 'Kinzel, Edward']",2024-03-26T20:27:20Z,2024-03-26T20:27:20Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124396', 'https://doi.org/10.26153/tsw/51004']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'glass']",Control of Track Morphology in Digital Glass Forming,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8a88a902-81ae-421d-a01d-7e93c7eb50ae/download,University of Texas at Austin,"Digital Glass Forming involves locally heating a glass filament using a laser while continuously feeding relative to
the workpiece. This enables precise control of the viscosity of the molten region. This viscous melt pool is deformed
by forces from the filament and workpiece. This paper investigates the relationships between the input parameters,
laser power, feed rate, and scan speed, with the resulting track morphology. Tracks are used to build larger, more
complex structures. By underfeeding the filament relative to the able scan speed, the glass is locally drawn to
produce tracks with significantly smaller cross-sectional areas than the feedstock material. This technique allows for
the production of arbitrary geometries and surface features using a smaller equivalent diameter than the input
feedstock. The paper explores the available process zone for this underfed deposition mode and the limitations of
this method.",,,,,,
"['Comb, James W.', 'Priedman, William R.']",2018-05-03T17:11:43Z,2018-05-03T17:11:43Z,1993,Mechanical Engineering,doi:10.15781/T2CJ8836K,http://hdl.handle.net/2152/65042,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Stratasys', 'Fused Deposition Modeling', 'FDM']",Control Parameters and Materials Selection Criteria for Rapid Prototyping Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3bd0a48d-d944-45de-92c8-f76d39af5a92/download,,"Since the introduction ofrapid prototyping technology as a tool for time
compression and concurrent engineering in the design and manufacturing process, many
enhancements and refinements have been made based on the experience ofusers and
manufacturers ofrapid prototyping equipment. These improvements contribute
significantly to faster production of quality output from rapid prototyping systems.
There are diverse control and material selection parameters that affect prototype
models built using the Fused Deposition Modeling (FDM®) process. This paper reviews
the role of several ofthese parameters in the process. Data will be presented to help the
user choose the appropriate material for specific applications including density, tensile
stiffhess, flexural stiffhess, tensile strength, flexural strength, tensile ductility, shock
resistance, and hardness.",,,,,,
"['Nycz, Andrzej', 'Noakes, Mark W.', 'Masuo, Christopher J.', 'Love, Lonnie J.']",2021-11-11T16:19:33Z,2021-11-11T16:19:33Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90234', 'http://dx.doi.org/10.26153/tsw/17155']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['control system framework', 'control system', 'G-code', 'printing paths', '3D printing', 'robot manipulator', 'robotic arm', 'degrees of freedom']",Control System Framework for Using G-Code-Based 3D Printing Paths on a Multi-Degree of Freedom Robotic Arm,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6948cc90-39cc-4d0a-9533-1619a6e00f8e/download,University of Texas at Austin,"This paper describes a control system framework using G-Code-based 3D printing paths on
a serial link robot manipulator with multiple degrees of freedom. Usually, G-Code is created by a
software application, commonly referred to as a slicer, meant for gantry systems. However, G-Code does not address the kinematic complexity nor take advantage of the flexibility available in
serial link robot manipulators. This paper provides an overview of the additive manufacturing
process and G-Code, types of additive manufacturing deposition movements, common
terminology used, the roles of parsers and translators, step-by-step instructions on how to
implement this control system, and results and findings from this research. The presented
framework can be used for a number of additive manufacturing methods, hybrid solutions, or
applications not directly related to additive manufacturing. The implementation was successfully
tested on a manipulator with seven degrees of freedom that successfully performed hundreds of
hours of large-scale wire arc metal deposition.",,,,,,
"['Levy, Gideon N.', 'Boehler, Paul', 'Martinoni, Raffaele', 'Schindel, Ralf', 'Schleiss, Peter']",2020-02-21T14:38:53Z,2020-02-21T14:38:53Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80057', 'http://dx.doi.org/10.26153/tsw/7079']",eng,2005 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Selective Laser Sintering', 'Elastomer']",Controlled Local Properties in the Same Part with Sintaflex A New Elastomer Powder Material for the SLS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0c33c8bd-2c49-43e2-bb01-f7af105e54d9/download,,"A new powder material for the SLS (Selective Laser Sintering) process was recently released.
The material is a result of fruitful research programs involving industry and university. The
well known and widely used DuraFom™ (PA12) and theCastForm™ (PS) SLS-materials were
developed by the same team.
In the search for new powder materials many properties of the candidate polymer, e.g. the
pulverization, the laser absorption and sintering parameters have to be tuned carefully. Previous
Elastomer options materials were poor in strength, detailing, and long-term use. The new
product overcomes most of the known deficits. It open completely new practices in many
branches like: automotive, house appliances, office equipment, foot ware, medical, and many
more. The Sintaflex has a Shore hardness variability 45-75 A and Elongation up to around
300%. The attainable yield strength range is 1.3 - 4.2 MPa. The resolution on the SLS part is up
to 0.6 mm. It is positioned in good agreement compared with other commonly used injection
plastics.
Furthermore, the appeal of all SFF process beside geometry and complexity is thought in
varying locally the mechanical properties. Some published patents make suggestions in this
direction. The new material, due to the particular properties range in function of the sintering
parameter, allows first time to realize this wish. The generated part has controlled variable local
properties; a new and unique opportunity opens for the SLS process.
The paper describes the basic material properties. Further the main sintering parameters are
describes and indications on machine settings are given. RP (Rapid Prototyping) applications
and the recent practical experience are illustrated. Distinctive examples of local variable
properties in the same part and given limits are shown. Some conclusions are stated.",,,,,,
"['Liu, Y.', 'Beck, S.', 'Nicolleau, F.', 'Majewski, C.E.']",2021-10-12T18:04:16Z,2021-10-12T18:04:16Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88709', 'http://dx.doi.org/10.26153/tsw/15643']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Sierpinski pyramids', 'laser sintering', 'air flow', 'turbulence', 'fluid flow', 'flow control']",Controlled Multi-Scale Turbulence through the Use of Laser Sintered Sierpinski Pyramids,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e696ae79-c58c-41a7-ad2e-24eb85c25d02/download,University of Texas at Austin,"The research presented here is the result of a new collaboration between the Centre for
Advanced Additive Manufacturing (AdAM) and the Thermofluids group at The University of
Sheffield, regarding the use of fractal geometries for the control and influence of fluid flow. It is
believed that the use of multiscale objects can be used to introduce many different orders of
turbulence into a flow. However, whilst substantial simulations have been carried out in this area,
the complexity of the physical geometries means that to date these have not been validated via
physical testing.
In this work, varying orders of Sierpinski pyramids were produced using Laser Sintered
PA2200 and analysed in a wind tunnel with regards to their effects on air flow through the
structures. As predicted by theoretical analyses, the coarsest pyramids induced large vortices into
the air-stream, whereas the more complex orders induced vortices at a number of different scales,
rapidly developing into a standard turbulent flow. Further investigations are planned to isolate
the effects of the smaller-scale turbulence in this situation.",,,,,,
"['Zak, Gene', 'Shiu, Matthew']",2019-10-09T16:22:45Z,2019-10-09T16:22:45Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76155', 'http://dx.doi.org/10.26153/tsw/3244']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Laminated,Controlled-Depth Laser Cutting of Aluminum Sheet for Laminated Object Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/199d09b0-7ef3-4529-bdf8-5417483beaf6/download,,"Replacing paper with metal in laminated object manufacturing would bring improvements in terms of
part's longevity, and its mechanical and thermal properties. In fabricating laminated parts, a challenging
step is blind cutting of the metal sheet. Challenges to overcome are (1) maintaining consistent depth of cut,
(2) achieving good surface quality of the cut groove walls, and (3) minimizing the formation of recast.
Results are presented of an experimental investigation into controlled-depth laser cutting of aluminum
sheet. Thin (0.12-mm) aluminum sheet specimens were cut with a 10-W Nd:YLF laser while varying
scan speed and laser power. To accurately observe the cut profiles, specimens were mounted in resin
and sectioned. Special handling procedure was developed to handle thin sheet material while avoiding
damage. Relationship between cut profile and process parameters was established and shown to
conform to established theoretical models.","We gratefully acknowledge the financial support of Centre for Automotive Materials and
Manufacturing and Canada Foundation for Innovation.",,,,,
"['Liu, Bochuan', 'Gibbons, Gregory J.']",2024-03-25T23:31:12Z,2024-03-25T23:31:12Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124337', 'https://doi.org/10.26153/tsw/50945']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['L-PBF', 'preferential evaporation', 'chemical composition', 'AlSi10Mg', 'tensile properties', 'additive manufacturing']",CONTROLLING CHEMICAL COMPOSITION CHANGES IN LASER POWDER BED FUSION OF ALSI10MG,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4113aa3-b725-4bfa-b788-deb8cc177641/download,University of Texas at Austin,"Due to the large energy input during the laser powder bed fusion process, some elements
of metal alloy will reach vaporisation temperature. Significant differences between the volatility
of various elements in the alloy may change the chemical composition after manufacturing. This
study used this preferential evaporation effect to control the final composition to a targeted value,
potentially for alloy and component tracing. Different laser process parameter sets were studied,
and the mechanical properties changes associated with various compositions were investigated.",,,,,,
"['Palmer, E.', 'Rosser, J.', 'Ritchie, M.', 'Bromley, C.', 'Brown, S.G.R.', 'Lavery, N.P.']",2023-03-30T16:00:37Z,2023-03-30T16:00:37Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117694', 'http://dx.doi.org/10.26153/tsw/44573']",eng,2022 International Solid Freeform Fabrication Symposium,Open,IN625,Controlling Grain Evolution of IN625 Parts Produced by LPBF-AM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e256991-f838-498b-b0c5-f533f7ea6916/download,,"Laser Powder Bed Fusion (LPBF) Additive Manufacturing (AM) is rapidly being 
adopted globally due to its capability of producing complex net-shape parts in a range of alloys 
with mechanical properties as good as, or better than conventional processes. The alluring 
possibility is in controlling microstructural features during processing such as grain size, 
solidification morphology and texture, giving mechanical properties tailored for intended 
applications.  LPBF-AM microstructures are dominated by sizeable columnar growth, which 
along with even small levels porosity contribute to lower fatigue and creep strength in 
comparison to wrought. This would limit high temperature applications where IN625 is used 
in aeroengine exhaust sections. In contrast, the less dominating equiaxed grains lead to a 
reduction in crack propagation and improve fatigue performance at the surface. In this work a 
combination of physical experiments and modelling is used to study the controllability of grain 
growth and orientation of IN625 made by LPBF-AM.",,,,,,
"['Soylemez, Emrecan', 'Beuth, Jack L.']",2021-09-30T19:01:40Z,2021-09-30T19:01:40Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88280', 'http://dx.doi.org/10.26153/tsw/15221']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['electron beam-based additive manufacturing', 'melt pool dimension', 'material deposition rates', 'electron beam deposition', 'electron beam']",Controlling Melt Pool Dimensions Over a Wide Range of Material Deposition Rates in Electron Beam Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/084f5aa6-1f5c-4494-babc-58dfcad0c981/download,University of Texas at Austin,"Electron beam-based additive manufacturing processes are being seriously considered for
manufacturing and repair applications in the aerospace industry. To be successful, these
processes must work over a wide range of material deposition rates to combine affordability
(requiring high deposition rates) with the ability to precisely deposit fine geometries (requiring
low deposition rates). Melt pool size and shape are key characteristics to control in these
processes. Control of melt pool dimensions will greatly increase the ability to successfully build
shapes, and may play an important role in controlling solidification microstructure. In this paper,
we present an analytically-guided approach for maintaining melt pool cross sectional area and
thermal finite element simulation results are presented over a wide power range (1-5kW) to
evaluate the approach. Single bead finite element simulations include the effects of temperature-dependent properties, latent heat, material addition and the distribution of power by a rapidly
moving beam. Experiments were carried out on electron beam deposition equipment at NASA
Langley Research Center and results show the same trends as those seen in the models.
Ultimately, a map of curves of constant melt pool cross sectional areas and length-to-depth ratios
is presented, covering power and velocity ranges over roughly a factor of 5.",,,,,,
"['Starr, Thomas L.', 'Rafi, Khalid', 'Stucker, Brent', 'Scherzer, Christopher M.']",2021-10-06T19:55:31Z,2021-10-06T19:55:31Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88426', 'http://dx.doi.org/10.26153/tsw/15363']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'stainless steels', 'phase composition']",Controlling Phase Composition in Selective Laser Melted Stainless Steels,Conference paper,https://repositories.lib.utexas.edu//bitstreams/971821cb-85d6-43ad-9cbb-380adfe40b8c/download,University of Texas at Austin,"Commercially important stainless steels can be austenitic or martensitic and this phase
composition fundamentally controls the mechanical properties of the material. With selective
laser melting (SLM), 17-4 stainless steel can be produced in either phase depending on powder
composition, SLM conditions and post-build heat treatment. This behavior is examined using
optical and electron microscopy and high temperature x-ray diffraction in order to better
understand the formation of metastable austenite and its transformation to martensite. Control of
phase composition can produce a material with either extremely large strain-to-failure or high
yield strength and can provide a method for completely eliminating residual stress.",,,,,,
"['Fussell, P.S.', 'Kirchner, H.O.K', 'Prinz, F.B.', 'Weiss, L.E.']",2018-04-17T18:18:46Z,2018-04-17T18:18:46Z,1991,Mechanical Engineering,doi:10.15781/T2H41K447,http://hdl.handle.net/2152/64342,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['rapid tooling', 'NOODLES', 'stereolithography']",Controlling the Microstructure of Arc Sprayed Shells,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f313338-f9ad-47d0-8841-e33ce583859d/download,,"Techniques for controlling the microstructure of sprayed steel structures are
discussed in this paper. Steel is arc sprayed onto shaped substrates to form tooling. The
quality of the tool is greatly influenced by the microstructure of the material and the interlamella
regions of the deposit. This work is focused on characterizing the microstructure,
improving the state of the inter-lamella regions, and discusses our success in forming
pseudo-alloys and graded shells by mixing sprayed materials. Microstructure control has
interesting implications for other research as well, such as the MASK & DEPOSITS approach
of forming objects.",,,,,,
"['Rüsenberg, S.', 'Weiffen, R.', 'Knoop, F.', 'Schmid, H.-J.']",2021-10-07T14:59:58Z,2021-10-07T14:59:58Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88471', 'http://dx.doi.org/10.26153/tsw/15408']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['laser sintered parts', 'laser sintering', 'powder quality', 'cooldown phase', 'process quality']",Controlling the Quality of Laser Sintered Parts Along the Process Chain,Conference paper,https://repositories.lib.utexas.edu//bitstreams/521213c7-46fc-4fd8-b7b2-186321e26c73/download,University of Texas at Austin,"The quality of laser sintered parts, in this work, manufactured by polymer laser sintering by
using an EOSINT P395 Laser Sintering system, depends on several steps along the process chain.
The first step is the characterization of the powder quality, whereas the rheological and physical
investigations of nylon 12 powder are shown. By changing some important influencing factors,
for example the powder ratio, the powder ageing and the moisture content, the influence on
mechanical and physical properties, density and porosity, are investigated. The composition of
the used powder is known. The previous process (storage conditions, etc.) as well as the laser
sintering process (regarding energy density, temperature, etc.) is kept constant for the duration of
this work. Regarding the post process in this work the cooling down phase is investigated as well.
With an automatically blasting system it is possible to keep the post process parameters blasting
distance and blasting time, constant. All of the tests will be performed using dry and conditioned
test specimens.
This work is showing the dependence on mechanical, rheological and physical parameters by
varying important influencing factors along the laser sintering process quality chain.",,,,,,
"['Milward, S.S.', 'Swygart, H.', 'Eccles, L.', 'Brown, S.G.R.', 'Lavery, N.P.']",2021-11-04T19:30:16Z,2021-11-04T19:30:16Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90010', 'http://dx.doi.org/10.26153/16931']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['co-efficient of thermal expansion', 'CTE', 'lattice structures', 'high precision optical system', 'laser powder bed fusion']",Controlling Thermal Expansion with Lattice Structures Using Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d546d12d-39cb-41a1-a333-25c3865474fe/download,University of Texas at Austin,"Tuning the Co-efficient of Thermal Expansion (CTE) of a component is traditionally limited by material
choice. Laser Powder Bed Fusion (LPBF) enables the designer to create complex geometries including lattice
structures. When combined with a secondary material, these metallic lattice structures can be designed to
exhibit different CTE’s whilst retaining stiffness. This allows the designer the freedom to adjust the CTE by
changing CAD variables such as lattice angle, and member thicknesses.
This paper aims to develop an arrangement for CTE matched components for high precision optical systems.
Development pursued using a Static Thermo-Structural Finite Element Analysis model to determine the best
arrangements for the required CTE change.
The results are incorporated into a new design prototype of a full cylindrical lens system in metal on a Laser
Powder Bed Fusion machine.",,,,,,
"['Masoomi, Mohammad', 'Soltani-Tehrani, Arash', 'Shamsaei, Nima', 'Thompson, Scott M.']",2021-11-11T16:34:39Z,2021-11-11T16:34:39Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90239', 'http://dx.doi.org/10.26153/tsw/17160']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'convective heat transfer coefficient', 'temperature gradient', 'numerical simulation']",Convection Heat Transfer Coefficients for Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/abc68337-42aa-4b11-9426-6e7a88f61820/download,University of Texas at Austin,"This study investigates the effects of convection heat transfer during the laser-powder bed fusion
(L-PBF) additive manufacturing process. For the L-PBF process, parts are fabricated under a
purged, inert environment to avoid oxidation. Part of the delivered laser energy is transferred to
the process chamber/environment through radiation and convection during fabrication. In this
study, customized computational fluid dynamics (CFD) software is used to simulate the L-PBF of
a single layer of stainless steel 17-4 PH. Local temperature and temperature gradients, as well as
dimensionless numbers descriptive of important thermophysics, are provided in order to quantify
local convective heat transfer. The results are used to predict local heat transfer coefficients during
the L-PBF additive manufacturing process.",,,,,,
"['Zhu, Feng', 'Chen, Ke-Zhang', 'Feng, Xin-An']",2020-02-17T14:18:06Z,2020-02-17T14:18:06Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79994', 'http://dx.doi.org/10.26153/tsw/7019']",eng,2004 International Solid Freeform Fabrication Symposium,Open,functionally graded materials,Converting a CAD Model into a Manufacturing Model for the Components Made of a Multiphase Perfect Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/46d57997-59fa-4091-a36f-5651774c4977/download,,"To manufacture the component made of a multiphase perfect material (including homogeneous
and multi heterogeneous materials), it CAD model should be processed and converted into
layered manufacturing model for further transformation of numerical control (NC) coding. This
paper develops its detailed approaches and corresponding software. The process planning is made
first and includes: (1) determining the build orientation of the component; and (2) slicing the
component into layers adaptively according to different material regions since different materials
have different optimal layer thickness for manufacturing. After the process planning, the layered
manufacturing models with necessary information, including fabrication sequence and material
information of each layer, are fully generated.",,,,,,
"['Kim, C.Y.', 'Cuaron, A.', 'Perez, M.A.', 'Espalin, D.', 'MacDonald, E.', 'Wicker, R.B.']",2021-10-12T21:19:27Z,2021-10-12T21:19:27Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88742', 'http://dx.doi.org/10.26153/tsw/15676']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['cooperative fabrication', 'harmonic fabrication', 'embedded three-dimensional wire in', 'degrees of freedom', 'Cartesian coordinate']",Cooperative Fabrication Methodology for Embedding Wireon Corved Surfaces,Conference paper,https://repositories.lib.utexas.edu//bitstreams/675364f3-0458-48db-beff-9f1192c1117d/download,University of Texas at Austin,"In conventional additive manufacturing (AM), an object is fabricated by depositing material in a
layer by layer fashion. Typically, this process is retained so that deposition can occur on flat
surfaces and motion can be constrained to requiring only three degrees of freedom (DOF) in a
Cartesian coordinate system. When incorporating wire in three-dimensional (3D) objects, there is
sometimes a need for placement along curved surfaces on which positions are defined not only
by 3D Cartesian coordinates but also angular ones. Therefore, a minimum of two additional
DOFs are required allowing movement to be generated at the build platform as well as of the
extrusion head. This paper addresses a method for trajectory planning of both systems, that is,
the extrusion head and the movable build platform, allowing for cooperative and harmonic
motion between the two.",,,,,,
"['Rhodes, Andrew', 'Walker, Roo', 'Smith, Tyler', 'Lindahl, John', 'Kunc, Vlastimil', 'Duty, Chad']",2021-12-06T21:43:37Z,2021-12-06T21:43:37Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90682', 'http://dx.doi.org/10.26153/tsw/17601']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['print parameters', 'fiber length', 'mechanical properties', 'fiber-reinforced composites', 'big area additive manufacturing']",Correlating Large-Format AM Print Parameters to Fiber Length and Mechanical Performance of Reinforced Polymer Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cf90fc05-8f89-4840-9ae4-3dc581555251/download,University of Texas at Austin,"This paper aims to correlate processing conditions to fiber length and mechanical
properties in fiber-reinforced composites on the Big Area Additive Manufacturing (BAAM)
system at Oak Ridge National Laboratory. The processing of fiber-reinforced composites has a
significant influence on their microstructure, which dictates the properties of the final product.
The effect of processing is poorly documented in systems like the BAAM, leaving significant
opportunities to improve the mechanical performance of printed structures. In this work, fiber
length distributions from pelletized feedstock were compared against those of specimens
extruded under different processing speeds. The mechanical strength of each specimen was
evaluated to correlate processing speed to fiber length and mechanical properties. Experimental
results showed that fiber length decreases slightly with increasing screw speed. Mechanical
performance was not found to be affected by the decrease in fiber length. This research will
guide future modifications to hardware design and print parameters to maintain fiber length and
maximize mechanical performance.",,,,,,
"['Lee, Y.S.', 'Bandari, Y.', 'Simunovic, S.', 'Richardson, B.', 'Kirka, M.M.']",2021-11-09T19:44:02Z,2021-11-09T19:44:02Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90143', 'http://dx.doi.org/10.26153/tsw/17064']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['LMD-wire', 'distortion', 'inter-layer time', 'finite element method', 'additive manufacturing', 'plate oscillation', 'Ti-6Al-4V']",Correlations of Interlayer Time with Distortion of Large Ti-6Al-4V Components in Laser Metal Deposition with Wire,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ddb9727-07d8-4c1b-b85c-e5f889da3000/download,University of Texas at Austin,"Laser metal deposition with wire (LMD-w) is one of the emerging additive
manufacturing (AM) technologies for large-scale aerospace components due to high deposition
rates and material efficiency. However, it often results in undesired stresses and distortions due
to non-uniform expansion and contraction of material during printing. Controlling inter-layer
time, preheating, and clamping are the effective methods to mitigate the thermally induced stress
and deformation. In this study, the effect of inter-layer cooling time on part distortion is
investigated using a finite element method (FEM). The model accounts for actual tool paths,
power, and cooling conditions. The results show that the model effectively captures the
fluctuation of the Ti-6Al-4V plate during printing. Also, it shows an asymmetric distortion on the
plate edges. Ultimately, the sequentially coupled thermal-stress simulation provided a
quantitative understanding of the inter-layer cooling time on titanium plate distortion for the
large-scale LMD-w process.",,,,,,
"['Ertay, Deniz Sera', 'Ma, Henry', 'Vlasea, Mihaela']",2021-11-09T15:27:15Z,2021-11-09T15:27:15Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90094', 'http://dx.doi.org/10.26153/tsw/17015']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['pore defects', 'beam path', 'toolpath', 'border discontinuities', 'laser powder bed fusion']",Correlative Beam Path and Pore Defect Space Analysis for Modulated Powder Bed Laser Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d513f523-0fe0-45e6-9848-2946f15faf76/download,University of Texas at Austin,"There are ongoing challenges in achieving full density metal parts via Laser Powder Bed
fusion (LPBF). Numerous of studies have shown that the part density depends on the process
parameters, the powder characteristics and the process environment conditions. The scan strategy
and the interactions of scan paths at discontinuities such as borders, create regions with high
probability of pore occurrence. In this work, the complex relation between the defects and the
toolpath at border discontinuities is investigated for a print recipe which gives >99.95% solid
fraction in the core of the part. Samples are scanned by X-ray Computed Tomography (CT). The
pore space was analyzed to extract the pore frequency, size, shape and location with respect to the
scan path, border and contour strategies.",,,,,,
"['Lindemann, Christian', 'Koch, Rainer']",2021-10-26T18:01:37Z,2021-10-26T18:01:37Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89542,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'product development processes', 'PDPs', 'cost efficiency']",Cost Efficient Design and Planning for Additive Manufacturing Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5de7d8bb-0446-47a3-abc9-c80a974310c9/download,University of Texas at Austin,,,This paper discusses additive manufacturing with regards to the current available PDP's while setting a focus on the economic aspects of the integration.,,,,
"['Baumers, M.', 'Holweg, M.']",2021-11-01T20:38:22Z,2021-11-01T20:38:22Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89738,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['manufacturing costs', 'build failure', 'laser sintering', 'additive manufacturing']",Cost Impact of the Risk of Build Failure in Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/09a029e5-f9ad-484b-b957-d67609e8dbac/download,University of Texas at Austin,"While the feasibility of adopting Additive Manufacturing (AM) has been demonstrated in
a range of industrial sectors, the total costs associated with the operation of the technology are not
fully understood. This study reports the results of a series of build experiments in a controlled
environment for the analysis of the total cost of the AM technology variant Laser Sintering (LS).
Incorporating a structured representation of the process flow of LS, the developed cost model
shows for a LS system of the type EOSINT P100 that the expected cost impact of build failure has
a substantial effect, responsible for a share of up to 38% of total costs. The analysis further
demonstrates that, due to the adverse effects of such ill-structured costs, the cost efficient level of
build volume utilization is sub-maximal. This result is discussed in the context of the operational
reality of using LS technology and the availability of economies of scale.",,,,,,
"['Barclift, Michael', 'Joshi, Sanjay', 'Simpson, Timothy', 'Dickman, Corey']",2021-11-01T20:55:42Z,2021-11-01T20:55:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89747,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['cost modeling', 'depreciation', 'resused powders', 'powder feedstocks', 'powder bed fusion', 'additive manufacturing']",Cost Modeling and Depreciation for Reused Powder Feedstocks in Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2115481-a9ed-4649-8239-8340e5d73c29/download,University of Texas at Austin,"Cost modeling for Powder Fusion (PBF) has traditionally treated the material feedstock
as a fixed cost. Given that a built-up geometry in PBF must be in a bed filled with surrounding
powder, the material feedstock is susceptible to satellites, chemical contamination, and dissimilar
properties with each subsequent reuse. In this paper, we extend an existing PBF cost model and
propose a new financial depreciation model for reused metal powders. Using Sum-of-the-Years
Digits depreciation, powder feedstock is valued as a function of build cycles endured by the
material feedstock. A case study is presented on two example parts in Direct Metal Laser
Sintering (DMLS). Results show that cost models using a fixed material cost can undervalue
build jobs with a high value virgin powder by as much as 3-11% or 13-75% depending on the
material and its maximum build cycles in PBF.",,,,,,
"['Kearns, Alexa', 'Farahbakhsh, Nasim', 'Venditti, Richard', 'Jur, Jesse']",2021-10-27T22:57:00Z,2021-10-27T22:57:00Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89641,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'cotton', 'pulverized cotton', 'low-density polyethylene', 'nanofibrillated cellulose', 'NFC']",Cotton Fibers in 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02310db7-492e-4a9e-b46f-e9f7af17ab28/download,University of Texas at Austin,"This work explores the materials challenges of cotton-loaded with polymer composites
toward sustainable solutions in 3D printed free forms. A key step toward composite filament
development is the reduction in size of the original cotton fibers. Mechanical processing of the
cotton is introduced as a means of reducing the size of cotton fibers to form a material of an ultra-high aspect ratio (>250) structure that is nanometers in diameter and micrometers in length.
Mechanical advantages are low density polyethylene loaded with the high aspect ratio cotton and
is observed to maintain a mechanically robust material at loading up to 40 wt%. In addition,
attempts to print with 25 wt% cotton fillers (~10-15 aspect ratio) in LDPE is demonstrated.
Finally, considerations to processing challenges from a sustainable and practical viewpoint are
provided.",,,,,,
"['McCarthy, D.L.', 'Williams, C.B.']",2021-10-05T15:52:50Z,2021-10-05T15:52:50Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88398', 'http://dx.doi.org/10.26153/tsw/15337']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'electroless plating', 'electroforming', 'laser sintering']",Creating Complex Hollow Metal Geometries using Additive Manufacturing and Electroforming,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97319f36-4ae6-4fa7-9def-be3e74f18d5c/download,University of Texas at Austin,"Additive manufacturing introduces a new design paradigm that allows the fabrication of
geometrically complex parts that cannot be produced by traditional manufacturing and assembly
methods. In this paper, the authors investigate the combination of laser sintering with an
electroforming process using electroless nickel plating to produce complex, thin-walled, hollow,
metal geometries. The resulting geometries cannot be produced directly with other additive
manufacturing systems. The resulting process is used to produce a cellular nickel structure
featuring 800µm walls that is 65 vol% air from a polyamide substrate with 3mm pores.",,,,,,
"['Phillips, T.', 'Milroy, C.', 'Beaman, J.']",2021-12-06T21:28:45Z,2021-12-06T21:28:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90677', 'http://dx.doi.org/10.26153/tsw/17596']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['lithium batteries', 'composite materials', 'conductivity', 'electroactivity']",Creating Conformable Lithium Batteries Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0d694d62-7465-4032-8a05-1a31e81b4be5/download,University of Texas at Austin,"Selective laser sintering is an additive manufacturing technique that uses a laser to
consolidate powdered material and create complex three dimensional parts. Typically, SLS
utilizes thermoplastic polymer media to create dense plastic components (direct SLS). It is also
possible, however, to use composite powders with non-melting additives paired with a suitable
binder to create highly functional materials (indirect SLS). This paper will describe the
formulation of composite materials containing conductive and electroactive material additives to
fabricate lithium-ion battery components (i.e. anodes, cathodes, separators, and cases). Selective
laser sintering adds to the geometric flexibility of the lithium battery components and enables
batteries that conform to their surroundings, effectively reducing their geometric footprint.
Preliminary galvanostatic charge/discharge test results will be presented for the functional Li-ion
cathodes created using SLS, as well as next steps to improve capacity and reliability.",,,,,,
"['Dumene, Richard L.', 'Kennedy, Paul', 'Williams, Christopher B.', 'Sweeney, Dennis', 'Earle, Greg']",2021-10-21T22:05:17Z,2021-10-21T22:05:17Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89456,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['radiofrequency', 'RF structures', 'embedding', 'PolyJet', 'material jetting']",Creating Embedded Radiofrequency Structures Using PolyJet Material Jetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/04ceb5ed-3337-409c-a438-5d2a48eada45/download,University of Texas at Austin,"Embedding of integrated systems via Additive Manufacturing (AM) offers the potential to save
weight, space, and time in the production of electronics and vehicles. Of specific interest are
embedded electrical systems that operate in the radiofrequency (RF) range as they have great
potential utility in communication systems and aircraft avionics including navigation. However,
systems in this frequency range pose unique manufacturing challenges such as the need to
minimize impedance discontinuities in the system. In this work, the authors explore various
techniques for embedding RF structures such as antennas and filters via a multi-material jetting
AM process. Specifically, the dielectric constants and loss tangents of Vero White and Tango
Black polymers were determined to facilitate the design of RF structures with these materials. It
is shown that measurements of S-parameters of the resultant embedded RF structures approach or
match the performance of non-embedded electronics.",,,,,,
"['Frank, Matthew C.', 'Joshi, Ashish', 'Lei, Shuangyan', 'Anderson, Donald D.', 'Tochigi, Yuki', 'Brown, Thomas D.']",2021-10-05T19:18:48Z,2021-10-05T19:18:48Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88415', 'http://dx.doi.org/10.26153/tsw/15354']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Subtractive Rapid Prototying', 'bone implants', 'human allograft bone']",Creating Implants from Allograft Bone using Subtractive Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0efb0040-f1d4-4d48-ab05-6e14636b4c07/download,University of Texas at Austin,"This research involves the development of rapid manufacturing for bone implants using human allograft
bone in a Subtractive Rapid Prototyping process. Using CT-derived CAD models of missing bone due to
high energy trauma or tumor resection, surgical reconstruction could be improved with custom rapid
implants made from natural bone. The bone “stock” material is of arbitrary shape and material
distribution in the form of frozen donated cadaveric bones. Each is unique in shape and has highly
anisotropic material properties; likewise for each final bone implant geometry and its material
distribution. This work utilizes a PLY input file, instead of the more common STL, using color texture
information that can be utilized for advanced process planning depending on whether the surface is
fracture, periosteal or articular in origin. Moreover, we present a new PLY assembly model, called the
Matryoshka model, where successively nested PLY files are used to designate changing material
distributions in the donated bone; a method that could also aid in the use of multi-material additive RP
systems. Using color Matryoshka models and their subsequent color slice files; this work presents novel
solution methods for the selection of implant harvesting sites and automated process planning for the
physical rapid prototyping process. Early implementations using bone surrogate materials will be
presented.",,,,,,
"['Roschli, Alex', 'Post, Brian', 'Chesser, Phillip', 'Borish, Michael', 'Love, Lonnie', 'Kim, Seokpum']",2021-11-18T16:51:55Z,2021-11-18T16:51:55Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90425', 'http://dx.doi.org/10.26153/tsw/17346']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['toolpaths', 'extruder modification', '3D printing', 'extrusion-based systems']",Creating Toolpaths Without Starts and Stops for Extrusion-Based Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb0ed156-649d-4419-b27e-13bdefcc6f62/download,University of Texas at Austin,"Toolpath generation for extrusion-based additive manufacturing systems, called slicing,
involves operations on polygonal contours that are derived from an STL file. Slicing generates
multiple paths per layer (both closed-loop and open-loop) that are designed to optimally fill the
space outlined by the polygon(s). In the course of printing a layer, the extruder must start and stop,
the tip must be wiped, and the extruder must travel between paths without printing. Any amount
of time the printer spends moving without printing is considered wasted time because the part isn’t
being constructed. In addition, the start/stop point, known as the seam, is often a blemish on the
surface of the part that contributes to weaker material properties. Therefore, a single path for
creating multi-bead walled structures is desirable because it would save machine time and create
parts with better surface finish. This paper will cover one method of modifying the CAD file and
slicing engine to allow for parts to be printed without starting and stopping the extruder.",,,,,,
"['Moeskops, Eef', 'Kamperman, Nico', 'van de Vorst, Bart', 'Knoppers, Rik']",2019-12-05T18:26:15Z,2019-12-05T18:26:15Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78652', 'http://dx.doi.org/10.26153/tsw/5708']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Polyamide,Creep Behaviour of Polyamide in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d9beaf74-76f1-42f0-bc25-a13e71ddbc72/download,,"The use of Rapid Prototyping technology to produce fully-functional end use products
(Rapid Manufacturing) requires understanding of the material's time dependency. Creep is the
time dependent strain as a result of a constant load. Creep behaviour of sintered polyamide-12
processed by the Selective Laser Sintering process has been investigated. To study the effect of
temperature on this material, tests have been performed at room temperature as well as at
elevated temperatures of 60°C and 100°C. Although the SLS processed material is more sensitive
to creep than most other thermoplastics it is shown to be affected less than injection molded
polyamide-12, which has been tested as a reference. The results show an almost linear behaviour
on a logarithmic time scale, which enables the creep behaviour of SLS processed polyamide-12
to be predicted for at least 11 years.",,,,,,
"['Schultz, J.', 'Kander, R.', 'Suchicital, C.']",2019-03-13T16:19:43Z,2019-03-13T16:19:43Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73641', 'http://dx.doi.org/10.26153/tsw/783']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'Mechanical Alloying']",Cryogenic Mechanical Alloying of Poly (ether ether ketone) - Polycarbonate Composite Powders for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9978f603-04cf-442f-b686-ad4fcfdb58cc/download,,"Mechanical alloying is a solid state processing technique traditionally used in the
metallurgical industry to extend solubility limits in alloy systems. Mechanical alloying can also
be used to blend polymer systems at ambient or cryogenic temperatures. In this work, cryogenic
mechanical alloying was employed to create composite powders of Poly (ether ether ketone)
(PEEK) - Polycarbonate (PC) for use in selective laser sintering applications. The
microstructural development of the PEEK-PC system that occurs during laser sintering and the
effects of this microstructure on mechanical properties of the laser sintered parts was
investigated.",,,,,,
"Wudy, K.",2021-11-18T01:41:15Z,2021-11-18T01:41:15Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90397', 'http://dx.doi.org/10.26153/tsw/17318']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'thermoset', 'thermoplastic', 'multi-material part']",Curing and Infiltration Behavior of UV-Curing Thermosets for the Use in a Combined Laser Sintering Process of Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/031c8c40-5536-463d-bbd9-d1c1f17a664d/download,University of Texas at Austin,"The investigation in this study addresses a new additive manufacturing process, which enables the
production of multi-material parts consisting of thermosets and thermoplastics. A liquid thermoset resin will be
applied with a micro value syringe in the laser sintering (LS) system. The liquid thermoset reacts parallel to the
laser exposure of the thermoplastic powder. Therefore, in this study the UV curing and the infiltration behavior
of the thermoset will be investigated under process relevant conditions. The investigations show a strong
temperature dependent absorption of the liquid in the powder bed, whereas, the surface tension of the liquid plays
a minor role. Furthermore, the UV curing of the thermosets takes place at low interaction times and at lamp
powers between 100 and 300 mW/cm².",,,,,,
"['Brady, G. Allen', 'Chu, Tien-Min', 'Halloran, John W.']",2018-11-14T20:47:02Z,2018-11-14T20:47:02Z,1996,Mechanical Engineering,doi:10.15781/T28C9RQ08,http://hdl.handle.net/2152/70264,,1996 International Solid Freeform Fabrication Symposium,Open,"['SL technique', 'uv-polymerized binder', 'HA ceramics']",Curing Behavior of Ceramic Resin for Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9078d708-b07c-44ee-805a-b9a5b514daba/download,,"Ceramic green bodies have been created with stereolithography methods by using ultraviolet curable
suspension of ceramic powders, a ""ceramic resin"", on a Stereolithography Apparatus (SLA).
A minivat system with mini-recoater blade was designed to run small batch experiments on an
SLA-250/40 machine. With the ceramic resins developed from hydroxyapatite for biomedical application
and from alumina and silica for making metal casting molds, ceramic green bodies were
built. Diagnostic parts of these ceramic resins were made with the Accumax diagnostic kit (3D
Systems) and the curing parameters determined. The effect ofshrinkage stress and scattering will
be discussed.",,,,,,
"['Wudy, K.', 'Drummer, D.']",2021-11-09T15:41:22Z,2021-11-09T15:41:22Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90099', 'http://dx.doi.org/10.26153/tsw/17020']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['curing behavior', 'thermosets', 'multimaterial SLS parts', 'selective laser sintering', 'additive manufacturing']",Curing Behavior of Thermosets for the Use in a Combined Selective Laser Sintering Process of Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a3e4cc8e-0d87-4cbc-9bae-ed6d95bbc36a/download,University of Texas at Austin,"Selective laser sintering (SLS) of polymers is an additive manufacturing process,
which enables the production of functional technical components. Unfortunately, the SLS
process is restricted regarding the materials that can be processed and thus resulting
component properties are limited.
The investigations in this study illustrates a totally new additive manufacturing process
which combines reactive liquids like thermoset resins and thermoplastics to generates multi
material SLS parts. To introduce thermoset resins into the regular SLS process, the time-temperature-dependent curing behavior of the thermoset and the infiltration behavior has to be
understood in order to assess the process behavior. The curing behavior was analyzed by
rotational viscosimeter. Furthermore, the fundamental infiltration behavior was analyzed with
micro dosing infiltration experiments. Finally, a thermoset resin in combination with a dosing
system was chosen for integration in a laser sintering system.",,,,,,
"['Law, Andrew Chung Chee', 'Southon, Nicholas', 'Senin, Nicola', 'Stavroulakis, Petros', 'Leach, Richard', 'Goodridge, Ruth', 'Kong, Zhenyu']",2021-11-09T14:59:52Z,2021-11-09T14:59:52Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90089', 'http://dx.doi.org/10.26153/tsw/17010']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'polymer powder bed fusion', 'in-process monitoring', 'fringe projection', '3D point cloud processing', 'curvature', 'segmentation']",Curvature-Based Segmentation of Powder Bed Point Clouds for In-Process Monitoring,Conference paper,https://repositories.lib.utexas.edu//bitstreams/432050c5-d01a-43ff-bd43-66f110bf7fc7/download,University of Texas at Austin,"This paper presents a curvature-based analysis of point clouds collected in-process
with fringe projection in a polymer powder bed fusion process. The three-dimensional
point clouds were obtained from outside of the build chamber with a fringe projection
measurement system which was provided with access through an observation window.
The curvature-based thresholding of powder bed point clouds demonstrates the ability
to separate consolidated areas from the powder bed effectively. This segmentation of the
point clouds with masks enables the detection of changes in the outline of consolidated
areas between layers, computation of average drop due to the consolidation of the powder
bed and separate analysis of both powder bed and consolidated areas. The high-level
insights extracted from the analysis of the point clouds could improve process
control strategies, such as in-line defect detection during an additive manufacturing
build as well as an in-process feedback system for tuning the optimal values of
additive process parameters. In summary, we show curvature-based thresholding as an
effective segmentation for fringe projection point clouds, which can be further applied
to detect defects, such as geometric defects and dimensional inaccuracy.",,,,,,
"['Klosterman, Donald A.', 'Chartoff, Richard P.', 'Osborne, Nora R.', 'Graves, George A.', 'Lightman, Allan', 'Han, Gyoowan', 'Bezeredi, Akos', 'Rodrigues, Stan']",2019-03-01T17:27:06Z,2019-03-01T17:27:06Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73513', 'http://dx.doi.org/10.26153/tsw/663']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'rapid prototyping']",Curved Layer LOM of Ceramics and Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/87b9a3a5-76fc-4614-9c36-40e8d3c47daa/download,,"A novel rapidprototyping (RP) technology incorporating a curved layer building
style has been developed. The new process,based on Laminated Object Manufacturing
(LOM), is suited for efficient fabrication of curved layer structures made from ceramics
and fibrous composites. Anew LOM machine was developedithatuses ceramic tapes
and fiberprepregs as a feedstock and outputs at11fee dimensional green form. The green
ceramic is then processed to a seamless, fully dense ceramic structure using traditional
ceramic techniques. Thisreport summarizes the new LOM process. and necessary
hardware. Also reviewed is the development of ceramic preforms and accompanying
process technology for net shape fabrication of ceramic matrix composites (CMCs).
Compared to making curved objeds with the standard flat.layer LOMprocess, the curved
process affordsthe advantages of eliminated stair-step effect,increased build speed,
reduced waste,reduced need for decubing, and the ability to maintain continuous fibers
in the direction of curvature.",,,,,,
"Kalmanovich, Gary",2018-11-14T17:20:08Z,2018-11-14T17:20:08Z,1996,Mechanical Engineering,doi:10.15781/T2H12VT2W,http://hdl.handle.net/2152/70244,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'manufacturing process', 'curved-layer']","""Curved-Layer"" Laminated Object Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/1fd8fc07-fd5a-420d-97e1-9dafbff943c1/download,,"A process where a freeform solid object is built by bonding cut layers of material together is
called a Laminated Object Manufacturing process. Until today, all ofthe LOM processes utilized
straight forward planar cross-sections of the intended object for manufacturing. The ""CurvedLayer""
project's objective is to perform the LOM manufacturing process on a non-planar crosssection.
Thus, the layers are going to be bonded together as non-planar surfaces providing
additional strength to the built part as well as expedition ofthe built time for many objects. This
project entails both software and hardware development for the implementation of the
manufacturing process.",,,,,,
"['Nambiar, R.V.', 'Jones, R.E.', 'Gomez, J.R.']",2019-10-18T16:52:50Z,2019-10-18T16:52:50Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76259', 'http://dx.doi.org/10.26153/tsw/3348']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Reconstruction,Custom Fabrication of Hard Tissue Reconstructive Frameworks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2bb1971e-1d46-4bac-be00-dea8204bff10/download,,"The feasibility of fabricating custom frameworks for tissue regeneration utilizing
three-dimensional inkjet printing technology followed by slip casting was investigated. A
CAD solid model of mold was created with structures within the mold cavity to provide
variable, customized porosity in the cast framework. The polymer mold was printed using
a 3D ink-jet printer. The mold was then infiltrated by an aqueous suspension of
hydroxyapatite to produce porous frameworks that were tested for mechanical properties.",,,,,,
"['Remmers, Richard', 'Cook, Doug', 'Gervasi, Vito']",2021-10-01T00:14:19Z,2021-10-01T00:14:19Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88305', 'http://dx.doi.org/10.26153/tsw/15246']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fluid power industry', 'custom pneumatic rotary actuator', 'active ankle-foot orthosis']","Custom, Integrated, Pneumatic, Rotary Actuator for an Active Ankle-Foot Orthosis",Conference paper,https://repositories.lib.utexas.edu//bitstreams/6eab6d2a-4e2e-4c21-b30a-be46b92a3f49/download,University of Texas at Austin,"End-use objects produced via additive manufacturing (AM) are on the rise and new
applications in the fluid power industry are emerging. Recently, a custom, pneumatic, rotary
actuator was been designed and additively manufactured for integration into an active ankle-foot
orthosis that is being developed in the National Science Foundation’s Center for Compact and
Efficient Fluid Power. All necessary plumbing, between the valves and vanes, is integrated into
the additively-manufactured housing of the actuator; and, the silicone translating seals were
vacuum-transfer molded using additively-manufactured molds and inserts. This nonconventional actuator has more theoretical torque, and weighs less, than the off-the-shelf
component that it replaced. Further development will reduce seal leakage, and optimize designs
for additional mass reduction. Results-to-date are presented, in addition to several other
examples of the growing use of AM in the fluid-power industry.",,,,,,
"['Mohammed, Mazhar I.', 'Fitzpatrick, Angus P.', 'Malyala, Santosh K.', 'Gibson, Ian']",2021-10-28T21:50:29Z,2021-10-28T21:50:29Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89709,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['patient specific', 'mandible', 'implant', 'design', '3D printing']",Customised Design and Development of Patient Specific 3D Printed Whole Mandible Implant,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6502fcd6-dc4b-43f7-9e7c-5148eb259ccc/download,University of Texas at Austin,"In this study we assessed the design criteria for the creation of a patient specific, whole
mandible implant based on a patient’s medical imaging data and 3D printing. We tailor this
procedure to a patient who will undergo a mandibulectomy due to cancer infiltration of the jaw.
The patient CT scan data was used to generate a 3D representation of the patient’s skull, before
the corrupted mandible was extracted. We examined two approaches based on classical
symmetry matching and digital reconstruction of the defect to form the final model for printing.
The final designs were then 3D printed and assessed for efficacy against a patient specific
representative model of the skull and maxilla, where the final optimised design was found to
provide an excellent fit. Ultimately, this technique provides a framework for the design and
optimisation of a patient specific whole mandible implant.",,,,,,
"['Singh, J.', 'Hauser, C.', 'Chalker, P.R.', 'Sutcliffe, C.J.']",2021-09-29T20:25:24Z,2021-09-29T20:25:24Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88214', 'http://dx.doi.org/10.26153/tsw/15155']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['adaptive slicing algorithm', 'Digital Light Processing', 'micro chemical reactors', 'layer based manufacturing']",Customised Layer Deposition for Chemical Reactor Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/92bf59fc-5ac2-4671-a284-5eeab058c9e6/download,University of Texas at Austin,"This paper discusses the development and application of an adaptive slicing algorithm for
use with Digital Light Processing (DLP) for the manufacture of micro chemical reactors. Micro
reactors have highly complex constructions and DLP has a proven ability to deliver features at
the micro level with high accuracy. However, DLP fails to provide a truly smooth profiled
surface finish which could influence fluid flow through entrance and exit apertures and along
snaking micro channels. Ensuring smooth surfaces will minimise energy losses in the fluid flow
path. Generally, layer based manufacturing techniques incur a trade off between build time and
resolution. The algorithms used in this study attempt to mitigate this to some degree by
calculating locations where high resolution is required through surface profiling techniques and
adjusts the layer thickness accordingly. It is proposed that this adaptive layering technique may
improve surface roughness and reduce friction related energy losses along micro channels within
chemical reactor applications.",,,,,,
"['Jones, J.', 'Jones, C.L.', 'Wimpenny, D.I.']",2021-09-29T17:48:21Z,2021-09-29T17:48:21Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88200', 'http://dx.doi.org/10.26153/tsw/15141']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['customised rapid manufactured parts', 'Custom-Fit project', 'CAD packages', 'European Commission']",Customised Rapid Manufactured Parts: Technology and Case Studies from the Custom-Fit Project,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c457cd0c-623f-4f4d-ae8e-af9f52db675e/download,,"The design and manufacture of individually customised products is generally restricted to
bespoke clothing or footwear for very wealthy customers. The aim of the Custom-Fit project was
to develop a fast, flexible and economically viable route for the manufacture of individually
customised parts. These products not only provide improved comfort levels but also provide
better functional performance, including enhanced safety for the user. This 4.5 year, European
Commission subsidised €16 million project, supported by the EU, involving 30 partners across
the breadth of the Europe finished in early 2009. This paper will showcase the technology
developed: CAD packages which automate the design process and three new rapid
manufacturing methods. It will also include case studies on a range of customised products,
including customised Motorcycles helmets. The case studies not only demonstrate the
performance benefits of individual customisation but also show the potential for new approaches
to product design. More information at www.Custom-Fit.org.",,,,,,
"['Sturm, L.D.', 'Williams, C.B.', 'Camelio, J.A.', 'White, J.', 'Parker, R.']",2021-10-18T20:40:06Z,2021-10-18T20:40:06Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89238,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'cyber-physical attacks']",Cyber-Physical Vulnerabilities in Additive Manufacturing Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56503a7b-0693-4a53-8532-01a1e489b7bf/download,University of Texas at Austin,"One of the key advantages of additive manufacturing (AM) is its digital thread, which allows
for rapid communication, iteration, and sharing of a design model and its corresponding physical
representation. While this enables a more efficient design process, it also presents opportunities
for cyber-attacks to impact the physical word. In this paper the authors examine potential attack
vectors along the Additive Manufacturing process chain. Specifically, the effects of cyber-physical attacks, and potential means for detecting them, are explored. Based on the results of
this study, recommendations are presented for preventing and detecting cyber-physical attacks on
AM processes.",,,,,,
"['BenAzouz, Aymen', ""O'Connor, Richard"", 'Vasquez, Mercedes', 'Brabazon, Dermot', 'Paull, Brett']",2021-09-30T13:19:46Z,2021-09-30T13:19:46Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88230', 'http://dx.doi.org/10.26153/tsw/15171']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['mutli-layered fabrication', 'microfluidic chips', 'cyclic olefin copolymer', 'COC chips', 'xurographic processing', 'laser processing']",Cyclic Olefin Copolymer Strip Processing for Freedom Fabrication of Multi-Layered Microfluidic Sensing Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc7054de-9be5-4834-bb0f-f69c20ac7239/download,University of Texas at Austin,"Researchers have developed techniques for multi-layered fabrication of microfluidic chips which
allow for increased scope of channel geometries and associated improved sensing capabilities. In
these techniques, slits have been fabricated in thin layers of polymer or glass, typically of a
couple of hundred micrometers thick. These layers are then bonded to each other using adhesives,
hot embossing or a combination of bonding methods. This paper presents a new fast freeform
methodology for 3D channel geometries to be fabricated in COC chips using laser and
xurographic processing for slit formation and cyclohexane promoted bonding for multi-layer
joining at room temperature.",,,,,,
"['Fang, Wei', 'Siang Ngooi, Chan', 'Gong, Haiqing']",2018-12-07T16:05:22Z,2018-12-07T16:05:22Z,1997,Mechanical Engineering,doi:10.15781/T2N58D62B,http://hdl.handle.net/2152/71441,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', '3D objects']",A data format providing side wall orientation and adaptive slicing for use in stepless rapid prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1141909a-e385-47f0-a50f-f468de587896/download,,"Current Rapid Prototyping systems mainly use 2D layers building techniques that result
in the 'staircase' effect on slanted surface. A new method has been developed to eliminate the
'staircase' effect and to improve the surface quality by extending the 2D layers to 3D layers
building. In this approach, a new data format, Layer Transfer Interface (LTI), is introduced to
generate layers having slanted side wall. It provides a faster slicing algorithm and accurate
reconstruction of 3D objects. This format is independent of any particular RP machines.
Furthermore, adaptive slicing has been achieved using this format and implemented on a fiveaxis
milling RP system.",,,,,,
"['Perišić, Milica', 'Milenković, Dimitrije', 'Lu, Yan', 'Jones, Albert', 'Ivezić, Nenad', 'Kulvatunyou, Boonserm']",2021-12-07T17:59:01Z,2021-12-07T17:59:01Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90738', 'http://dx.doi.org/10.26153/tsw/17657']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['data integration framework', 'data integration', 'data management', 'additive manufacturing']",A Data Integration Framework for Additive Manufacturing Big Data Management,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e5faba3e-06ae-4390-8d14-fab302bbc210/download,University of Texas at Austin,"Large amounts of data are generated throughout the entire, AM, part-development lifecycle. Data
are generated by various functions within process monitoring, material characterization,
equipment status, and part qualification. Hence, data integration and management are critical in
streamlining, accelerating, certifying, and deploying these functions. However, achieving that
integration and management has several challenges because AM data embodies the four
characteristics of Big Data - volume, velocity, variety, and veracity. This paper proposes an AM
framework as a foundation for addressing those challenges. In the framework, AM data are
streamed, curated, and configured automatically for real-time analysis and batch processing, which
increases the effectiveness of archiving and querying that data. The framework also includes a
description of the associated AM metadata, which links the various data types and improves
browsing, discovering, and analyzing that data. Finally, the framework can be used to derive
requirements for standards that enable data sharing.",,,,,,
"['Baldwin, Martha', 'Meisel, Nicholas A.', 'McComb, Christopher']",2023-03-01T17:17:53Z,2023-03-01T17:17:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117549', 'http://dx.doi.org/10.26153/tsw/44429']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Lattice  Structure,A Data-Driven Approach for Multi-Lattice Transitions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1559df14-4360-4ce7-ba10-fa5906044501/download,,"Additive manufacturing is advantageous for producing lightweight components while 
maintaining function and form. This ability has been bolstered by the introduction of unit lattice 
cells and the gradation of those cells. In cases where loading varies throughout a part, it may be 
necessary to use multiple lattice cell types, also known as multi-lattice structures. In such 
structures, abrupt transitions between geometries may cause stress concentrations, making the 
boundary a primary failure point; thus, transition regions should be created between each lattice 
cell type. Although computational approaches have been proposed, smooth transition regions are 
still difficult to intuit and design, especially between lattices of drastically different geometries. 
This work demonstrates and assesses a method for using variational autoencoders to automate the 
creation of transitional lattice cells. In particular, the work focuses on identifying the relationships 
that exist within the latent space produced by the variational autoencoder. Through computational 
experimentation, it was found that the smoothness of transition regions was higher when the 
endpoints were located closer together in the latent space.",,,,,,
"['Sammons, P.M.', 'Bristow, D.A.', 'Landers, R.G.']",2021-10-21T18:34:54Z,2021-10-21T18:34:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89422,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Laser Metal Deposition', 'layer-to-layer stability', 'stability criterion', 'process planning', 'process control']",DC-Gain Layer-to-Layer Stability Criterion in Laser Metal Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e97acf2-7c1f-48b8-87f2-0014c39f7b91/download,University of Texas at Austin,"In Laser Metal Deposition (LMD), a blown powder metal additive manufacturing
process, functional metal parts are fabricated in a layer-by-layer fashion. In addition to the inlayer dynamics, which describe how the process evolves within a given layer, the additive-fabrication property of LMD creates a second set of dynamics which describe how the process
evolves from layer-to-layer. While these dynamics, termed layer-to-layer dynamics, are coupled
with both the in-layer dynamics and the process operating conditions, they are not widely
considered in the modeling, process planning, or process control of LMD operations. Because of
this, seemingly valid choices for process parameters can lead to part failure – a phenomenon
commonly encountered when undergoing the laborious procedure of tuning a new LMD process.
Here, a layer-to-layer stability condition for LMD fabrications is given, based on the shape of the
powder catchment efficiency function, which provides insight into the layer-to-layer evolution of
LMD processes and can be useful in process planning and control. The stability criterion is
evaluated for various operating points, allowing stable and unstable operating regions to be
identified. Simulation results are presented showing both stable and unstable layer-to-layer
LMD fabrications. The simulated behavior successfully predicts the results seen in both stable
and unstable experimental depositions.",,,,,,
"['Liu, X.', 'Mileo, A.']",2021-12-01T22:53:57Z,2021-12-01T22:53:57Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90645', 'http://dx.doi.org/10.26153/tsw/17564']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['deep learning', 'defect detection', 'titanium alloys', 'additive manufacturing']",A Deep Learning Approach to Defect Detection in Additive Manufacturing of Titanium Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/419fef57-4807-438c-98c9-f0d15ad29714/download,University of Texas at Austin,"In Additive Manufacturing (AM) of titanium alloys, the formation of defects in parts is typically related
to the stability of the melt pool. With increased instability and size of the melt pool comes an increase in the level
of emissions generated as the laser processes the material. Recent developments with in-situ monitoring and
process control allows the collection of large amounts of data during the printing process. This includes data about
emissions, which are made available as 2D representations in the form of colour images. However, it is still a
manual process to inspect these 2D representations to identify defects, which hinders scalability. Given recent
advances in Deep Learning for computer vision and the availability of large amounts of data collected from in-situ monitoring, our approach leverages Deep Learning techniques for characterizing abnormal emissions to
automatically identify defects during the printing process. One of the challenges to apply deep learning in AM is
the lack of proper labelled data for training the models. In this paper, we tackle this challenge by proposing an
approach that uses transfer learning and fine-tuning on a pre-trained Convolutional Neural Network (CNN) model
called VGG 16 to successfully train the deep model with a small labelled dataset. Results show good classification
accuracy on the emission images obtained from the in-situ monitoring system, and improvements in classification
of defects on a public industrial benchmark datasets named DAGM (Deutsche Arbeitsgemeinschaft für
Mustererkennung e.V., German chapter of the IAPR).",,,,,,
"['Khalid-Rafi, H.', 'Karthik, N.V.', 'Starr, Thomas L.', 'Stucker, Brent E.']",2021-10-06T20:03:38Z,2021-10-06T20:03:38Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88428', 'http://dx.doi.org/10.26153/tsw/15365']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['EBM parts', 'electron beam melting', 'defect formation', 'horizontal orientation']",Defect Formation in EBM Parts Built in Horizontal Orientation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/55f49f73-c39b-4543-a36c-092ae884df2b/download,University of Texas at Austin,"EBM built parts in a horizontal orientation, particularly with bottom curved surfaces, are prone
to variations in dimensional accuracy and defect formation. These defects likely occur due to the
nature of the supports utilized and the build strategy. To understand the effect of support
structures and scan direction on these defects, a series of cylindrical parts were built using
different diameters, support structures and scan strategies. The as-built samples were
mechanically tested and sample cross sections were analyzed. Pore formation and balling effects
were observed in the lower section of some samples. The study looks at the effects of supports,
geometry and scan strategy on the minimization of these defects and improving the dimensional
accuracy of horizontally built samples.",,,,,,
"['Gong, Haijun', 'Rafi, Khalid', 'Karthik, N.V.', 'Starr, Thomas', 'Stucker, Brent']",2021-10-11T20:31:29Z,2021-10-11T20:31:29Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88632', 'http://dx.doi.org/10.26153/tsw/15566']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'Electron Beam Melting', 'defects', 'morphology', 'process parameters', 'porosity']",Defect Morphology in Ti-6Al-4V Parts Fabricated by Selective Laser Melting and Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82fe1e59-cfd1-4332-98f1-cb3fa6db8f46/download,University of Texas at Austin,"In order to investigate the morphology of defects present in Selective Laser Melting (SLM)
and Electron Beam Melting (EBM) processes, Ti-6Al-4V specimens were fabricated with varying
porosity using non-optimum processing parameters. Defective specimens were sectioned and
polished for microscopy. Image processing was adopted for statistically analyzing the
characteristics of defects, such as distribution of defect area and dimensional proportion of each
defect. It is found that defect morphology is influenced by process parameters as a result of a
variation in the melt pool. Image processing of a cross-section could be a feasible way for
calculating porosity of specimens.",,,,,,
"['Gaja, Haythem', 'Liou, Frank']",2021-11-04T18:22:03Z,2021-11-04T18:22:03Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89997', 'http://dx.doi.org/10.26153/16918']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'acoustic emission', 'deposition defects', 'clustering analysis']",Defects Classification of Laser Metal Deposition Using Acoustic Emission Sensor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0d207cb7-0176-4e12-b0f5-e49dadd95378/download,University of Texas at Austin,"Laser metal deposition (LMD) is an advanced additive manufacturing (AM) process used
to build or repair metal parts layer by layer for a range of different applications. Any presence of
deposition defects in the part produced causes change in the mechanical properties and might
cause failure to the part. In this work, defects monitoring system was proposed to detect and
classify defects in real time using an acoustic emission (AE) sensor and an unsupervised pattern
recognition analysis. Time domain and frequency domain, and relevant descriptors were used in
the classification process to improve the characterization and the discrimination of the defects
sources. The methodology was found to be efficient in distinguishing two types of signals that
represent two kinds of defects. A cluster analysis of AE data is achieved and the resulting
clusters correlated with the defects sources during laser metal deposition.",,,,,,
"['Li, Anyi', 'Liu, Jia', 'Shao, Shuai', 'Shamsaei, Nima']",2023-02-09T15:46:21Z,2023-02-09T15:46:21Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117436', 'http://dx.doi.org/10.26153/tsw/44317']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser beam powder bed fusion', 'X-ray CT', 'Hierarchical graph convolutional  network', 'Defects classification']",Defects Classification via Hierarchical Graph Convolutional Network in L-PBF Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3d7305a2-e91c-4144-b5be-00a0496491e6/download,,"Three typical types of defects, i.e., keyholes, lack of fusion (LoF), and gas-entrapped pores 
(GEP), characterized by various features (e.g., volume, surface area, etc.), are generated under 
different process parameters of laser beam powder bed fusion (L-PBF) processes in additive 
manufacturing (AM). The different types of defects deteriorate the mechanical performance of L-
PBF components, such as fatigue life, to a different extent. However, there is a lack of recognized 
approaches to classify the defects automatically and accurately in L-PBF components. This work 
presents a novel hierarchical graph convolutional network (H-GCN) to classify different types of 
defects by a cascading GCN structure with a low-level feature (e.g., defect features) layer and a 
high-level feature (e.g., process parameters) layer. Such an H-GCN not only leverages the multi-
level information from process parameters and defect features to classify the defects but also 
explores the impact of process parameters on defect types and features. The H-GCN is evaluated 
through a case study with X-ray computed tomography (CT) L-PBF defect datasets and compared 
with several machine learning methods. H-GCN exhibits an outstanding classification 
performance with an F1-score of 1.000 and reveals the potential effect of process parameters on 
three types of defects.",,,,,,
"['Soar, R.C.', 'Dickens, P.M.']",2018-11-30T16:43:08Z,2018-11-30T16:43:08Z,1997,Mechanical Engineering,doi:10.15781/T2B56DQ7X,http://hdl.handle.net/2152/70598,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Laminated Tooling', 'Rapid Prototyping']",Deflection and the Prevention of Ingress within Laminated Tooling for Pressure Die-Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e86ee249-ccaf-47b3-a584-7f1d5128a6f7/download,,"Wrthin the context ofrapid tooling, we are currently assessing the fundamental limitations
oflaminated tooling for pressure die-casting (PDC) applications. The use ofindividual laminates
to form a die-cast tool presents it own problems, namely the prevention of excessive deflection
that may lead to the ingress of pressurised molten aluminium between laminates. Ultimate
solutions lie with bonding and clamping techniques of which work is already underway. This
paper describes an initial study to establish the fundamental laminated die behaviour in extreme
die-casting environments.",,,,,,
"['Crane, N.B.', 'Lusk, C.P.', 'Nussbaum, J.', 'Consuegra Reyes, Y.']",2021-10-07T17:50:42Z,2021-10-07T17:50:42Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88494', 'http://dx.doi.org/10.26153/tsw/15428']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'post processing', 'deformation', 'planar manufacturing', '3D printing']",Deformation Post-Processing of Additive Manufacturing Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69655cf5-e12e-4623-8dc9-b9514a5d4c79/download,University of Texas at Austin,"Parts produced by additive manufacturing (AM) often require post processing to improve
surface finish and mechanical properties. However, little attention has been given to including
deformation in the post processing. Deformation post-processing can address some part size,
manufacturing cost, and geometry limitations of 3D printing. Additionally, it could be used to
create 3D surfaces using planar manufacturing processes (such as printed circuit board
manufacturing). The challenge of deformation post-processing is the design of the correct
fabrication state to produce the desired final state and the accurate deformation of the parts to the
desired final state. This paper demonstrates the geometric capability, potential applications, and
methods for accurately and repeatedly deforming the initial geometry to the desired
configuration using features in the parts.",,,,,,
"['Lipkowitz, Gabriel', 'Desimone, Joseph M.']",2024-03-26T16:59:34Z,2024-03-26T16:59:34Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124373', 'https://doi.org/10.26153/tsw/50981']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['resin', '3D printing', 'paraflow', 'fluid dynamics', 'additive manufacturing']",Demonstrating Paraflow: Interactive fluid dynamics simulation with real-time visualization for augmented resin 3D printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7a959257-8c13-4222-952f-b96ba4ff2846/download,University of Texas at Austin,"While resin 3D printers are seeing growing adoption in both manufacturing and personal
fabrication settings, detecting print failures in real time remains challenging. Object-detection
neural networks have shown benefits in a variety of extrusion-based 3D printing methods. Here,
we extend such work to resin printing using a physics-informed machine learning data generation
pipeline. Our approach leverages our models of the fluid dynamics of the printing process at
every slice, in order to synthetically generate a library of print defects. We show such an
approach is capable of providing data sufficiently resembling real-world failures to fine-tune a
pre-trained custom defect detection neural network that can alert users of failure in real-time.
Finally, to allow novice users to take advantage of our simulation platform, we integrate our tool
into an interactive augmented reality interface, which displays simulation predictions to provide
guidance on design and machine parameters prior to printing.",,,,,,
"['Berzins, M.', 'Childs, T.H.C', 'Dalgarno, K.W.', 'Ryder, G.R.', 'Stein, G.']",2018-10-10T16:00:28Z,2018-10-10T16:00:28Z,1995,Mechanical Engineering,doi:10.15781/T2DB7W864,http://hdl.handle.net/2152/68759,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Thermal distortions', 'polycarbonate parts', 'selective laser sintering']",Densification and Distortion in Selective Laser Sintering of Polycarbonate,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d314871a-f26b-4a3e-b9ef-2ec5d11d5c6c/download,,"The creation of a 3D numerical model for real part accuracy simulations is the goal of
this work. An improvement of a first attempt to predict densification, which used a
classical moving heat source calculation and a viscous sintering model, is reported: it
includes a numerical thermal calculation with thermal properties allowed to vary with
temperature. A study of polycarbonate part 'curl' distortion is also reported. The
development of curl at part edges and with part thickness is followed. Mechanical and
thermal reasons are sought as to why the distortion is concentrated at edges.",,,,,,
"['Rao, T. Srinvasa', 'Bourell, D.L.', 'Marcus, H.L.']",2018-11-08T15:10:15Z,2018-11-08T15:10:15Z,1995,Mechanical Engineering,doi:10.15781/T2C53FM37,http://hdl.handle.net/2152/69884,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SLS', 'hot isostatic pressing']",Densification Behavior of SLS Processed Al2O3/Al Composite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3584cbb-034f-4987-820b-9feca7ab9b48/download,,"Production of structurally sound parts by any rapid prototype technique is essential, because
fully functional features are necessary where application testing is required. In the present work,
a powder blend of A1203/AI (3:1 by weight) was mixed with ammonium dihydrogen phosphate
and subjected to selective laser sintering (SLS) using a C02 laser. An attempt has been made
to increase the powder bed density by introducing vibration to the part cylinder. These SLS
processed preforms were then subj ected to a secondary heat treatment in a hydrogen
atmosphere and to hot isostatic pressing. Densification behavior of these Al20 3/Al composite
preforms is discussed.",,,,,,
"['Beaman, Joseph Jr.', 'Agarwala, Mukesh K.', 'Bourell, David L.']",2018-09-26T20:05:29Z,2018-09-26T20:05:29Z,1994,Mechanical Engineering,doi:10.15781/T2NV99W1V,http://hdl.handle.net/2152/68592,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['metal matrix alloy', 'selective laser sintering', 'three-dimensional fully functional parts']",Densification of Selective Laser Sintered Metal Part by Hot Isostatic Pressing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e60d4c4b-d83b-487c-a6e5-ecce1f5ba728/download,,"Metal matrix alloy composite parts were made from powders by Selective Laser Sintering (SLS).
In this study, partially dense (60%-80%) metal parts made by SLS were densified to full density
(>98%) by hot isostatic pressing (HIPping) without any loss of shape. HIPping was done by
vacuum sealing SLS samples in glass capsules. HIPping parameters, such as, temperature,
pressure, and time, were studied with respect to density, linear shrinkage, and microstructures.
Anisotropy in linear shrinkage was correlated to the SLS processing parameters. Densification
resulting from HIPping was correlated to microstructures and theoretical HIP densification maps.
A detailed analysis of such maps is presented.",,,,,,
"['Raghavan, S.', 'Nai, Mui Ling Sharon', 'Wang, Pan', 'Sin, Wai Jack', 'Li, Tao', 'Wei, Jun']",2021-10-27T21:41:14Z,2021-10-27T21:41:14Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89623,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['heat treatment', 'microstructure', 'tensile property', 'Ti-6Al-4V', 'electron beam melting']",Dependence of Microstructure and Mechanical Properties on Heat Treat Cycles of Electron Beam Melted Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11093d6e-1eb2-418c-af8e-eff9902a36fd/download,University of Texas at Austin,"The EBM Ti-6Al-4V alloy has generally superior mechanical properties, owing to finely
spaced α−β laths which give a good combination of strength and ductility. The grain structures in
the as-printed structures are long columnar which can give rise to anisotropic mechanical
properties. Moreover the non-uniformity in microstructure can also arise from part geometry
where the thin features have propensity to form martensite phase. Heat treatment provides a
viable solution to modify the microstructure and to tailor to the properties as desired. A wide
range of heat treatment experiments were performed, followed by microstructure and tensile
property analyses. It was observed that the microstructure and the tensile properties significantly
changed depending on the heat treat cycle performed. Tensile properties of solution treated air-cool plus aged samples yielded globular equiaxed grains with fine α−β lath structure, which were
found to be the best among the different heat treated samples and better than ASTM F1472
specifications.",,,,,,
"['Lammers, S.', 'Koers, T.', 'Magyar, B.', 'Zimmer, D.', 'Lieneke, T.']",2024-03-26T17:01:23Z,2024-03-26T17:01:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124374', 'https://doi.org/10.26153/tsw/50982']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['technical drawings', 'support structures', 'ISO 128-3', 'additive manufacturing']",DEPICTION OF SUPPORT STRUCTURES IN TECHNICAL DRAWINGS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08a37fcd-265a-4b5e-969d-839d63238c69/download,University of Texas at Austin,"To ensure uniform documentation of support structure information, a concept is presented that enables a
standardized depiction of support structures in technical drawings based on ISO 128-3. To this end, requirements
for a uniform depiction are defined and a procedure for drawing entry is presented. The drawing entry should
contain all production-relevant support structure information. The standardized documentation of support
structure information in technical drawings is intended to ensure a simple, clear and safe exchange of information
between business units or different companies along the value chain. As a result a possible drawing entry of
support structures was developed. To distinguish between different support structure types, a standardized
depiction of geometrical information in a specification field is shown. The specification field gives a detailed
description of the support structure type, the geometry as well as the connection to the part and the building
platform. Also uncommon support types like lattice structures or CAD based support structures can be
implemented. To ensure the usability the depiction is editable and extendable.",,,,,,
"['Watson, Nathan D.', 'Von Lockette, Paris']",2021-11-10T22:26:46Z,2021-11-10T22:26:46Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90192', 'http://dx.doi.org/10.26153/tsw/17113']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['deposition controlled', 'magnetic alignment', 'iron-PLA composites', 'fused filament fabrication']",Deposition Controlled Magnetic Alignment in Iron-PLA Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ee2debe-a602-431b-a74f-ccf897349e54/download,University of Texas at Austin,"By manipulating the print plane, infill direction, and geometry of Fused Filament
Fabricated (FFF) iron-PLA composite parts, the alignment of their magnetic axes can be
influenced. FFF printing allows control of deposition direction, which affects the arrangement of
the iron within the composite part in ways that induce preferred magnetic orientation, the so-called easy axis. Qualitative results show the direction of deposition of the composite iron-PLA
filament has significant effects on the response of the printed parts to an external magnetic field.
Results further show that across different geometries, the easy axis of a printed part can be
prescribed by setting the print plane and infill direction parallel to the desired
orientation. Expected part geometry effects, along with the print plane and infill
influences, suggest the phenomenon can be modeled using multi-scale demagnetizing field
theories to print magneto-sensitive devices that can perform localized, controlled actuation in a
uniform magnetic field.",,,,,,
"['Janaki Ram, G.D.', 'Yang, Y.', 'Stucker, B. E.']",2020-03-10T16:08:16Z,2020-03-10T16:08:16Z,9/5/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80220', 'http://dx.doi.org/10.26153/tsw/7239']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Laser Engineered Net Shaping,Deposition of Ti/TiC Composite Coatings on Implant Structures Using Laser Engineered Net Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/70acce11-de53-4b48-84e3-4097c4ee4603/download,,"A new method of depositing hard and wear resistant composite coatings on metal-onmetal bearing surfaces of titanium implant structures is proposed and demonstrated. The method
consists of depositing a Ti/TiC composite coating (~ 2.5 mm thick) on titanium implant bearing
surfaces using Laser Engineered Net Shaping (LENS®). Defect-free composite coatings were
successfully produced at various amounts of the reinforcing TiC phase with excellent interfacial
characteristics using a mixture of commercially pure Ti and TiC powders. The coatings consisted
of a mixture of coarser unmelted/partially melted (UMC) TiC particles and finer, discreet
resolidified (RSC) TiC particles uniformly distributed in the titanium matrix. The amounts of
UMC and RSC were found to increase with increasing TiC content of the original powder
mixture. The coatings exhibited a high level of hardness, which increased with increasing TiC
content of the original powder mixture. Fractographic studies indicated that the coatings, even at
60 vol.% TiC, do not fail in a brittle manner. Various aspects of LENS® deposition of Ti/TiC
composite coatings are addressed and a preliminary understanding of structure-property-fracture
correlations is presented. The current work shows that the proposed approach to deposit
composite coatings using laser-based metal deposition processes is highly-effective, which can
be readily utilized on a commercial basis for manufacture of high-performance implants.",,,,,,
"['Lee, Y.L.', 'Tompkins, J.V.', 'Sanchez, J.M.', 'Marcus, H.L.']",2018-11-08T15:42:35Z,2018-11-08T15:42:35Z,1995,Mechanical Engineering,doi:10.15781/T2B56DQ4G,http://hdl.handle.net/2152/69892,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SALD', 'CVD systems', 'TMS pressure']",Deposition Rates of Silicon Carbide by Selected Area Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/34350d68-771a-489a-a463-47287ed831da/download,,"The deposition rates using pure tetramethylsilane (TMS) as precursor are calculated numerically
for a ~od .grown by th~ .Selected Area Laser Dep?sition J?rocess. In particular, the dependence of
the kinettcs of deposItion on pressure of TMS IS examIned. The conditions for which volcano
d~pos~tion pr?files occur are also investigated. The results show that deposition rate increases
wIth IncreasIng pressure and then becomes saturated. In addition, adsorption-desorption
phenomena, rather than effects ofreactants depletion, are responsible for the volcano deposition
profile observed experimentally",,,,,,
"['Gaja, Haythem', 'Liou, Frank']",2021-10-19T21:16:54Z,2021-10-19T21:16:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89340,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['depth of cut detection', 'acoustic emission', 'artificial neural network']",Depth of Cut Monitoring for Hybrid Manufacturing Using Acoustic Emission Sensor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fe3c04e9-702c-45f5-b549-f6d775d3b70a/download,University of Texas at Austin,"Laser Metal Deposition LMD is a hybrid manufacturing process consist of a laser
deposition system combined with a 5-axis CNC milling system. During laser deposition many
parameters and their interaction affect the dimensional accuracy of the part produced, powder flow
rate, laser power and travel speed are some of these parameters. Sensing the acoustic emission
during milling marching gives feedback information regarding depth of metal being cut subsequent
part dimensions, if an error in dimensions is found certain actions, such as remaching, close loop
control, or laser remelting can be carried out to correct it. Thus a reliable hybrid manufacturing
management system requires that a depth-of-cut detection system be integrated with the milling
machine architecture. This work establishes, first a methodology to detect an acoustic emission
signal, so that the acoustic emission characteristics of the milling could be analyzed. Second, it
sought to relate these acoustic data to machining parameters to detect depth-of-cut.",,,,,,
"['Pallari, J.H.P.', 'Dalgarno, K.W.', 'Munguia, J.', 'Muraru, L.', 'Peeraer, L.', 'Telfer, S.', 'Woodburn, J.']",2021-10-01T00:21:14Z,2021-10-01T00:21:14Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88307', 'http://dx.doi.org/10.26153/tsw/15248']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['foot orthoses', 'ankle-foot orthoses', 'additive fabrication', 'additive fabrication technology']",Design and Additive Fabrication of Foot and Ankle-Foot Orthoses,Conference paper,https://repositories.lib.utexas.edu//bitstreams/95434e2e-169f-422f-bafb-7dc4cea77e8d/download,University of Texas at Austin,"Foot and ankle-foot orthoses are prescribed in order to promote mobility through supporting
and/or realigning the lower leg and alleviating pain in the foot in different parts of the gait
cycle. This paper will outline new approaches to the design and manufacture of personalised
foot and ankle-foot orthoses (FO and AFO) using additive fabrication technology. The
research is addressing the need for specific software design tools for orthosis design which
enable their properties to be locally tailored within a mass customisation framework.
Structure/material testing to support that activity is also being undertaken and will be
described.",,,,,,
"['Mulholland, T.', 'Felber, R.', 'Rudolph, N.']",2021-11-08T22:44:43Z,2021-11-08T22:44:43Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90061', 'http://dx.doi.org/10.26153/tsw/16982']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'FFF', 'thermal conductivity', 'additive manufacturing']",Design and Additive Manufacturing of a Composite Crossflow Heat Exchanger,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc8cc501-be97-4707-b926-3179e27683e3/download,University of Texas at Austin,"Additive manufacturing (AM) with composite materials reveals new possibilities for
direct manufacturing of end-use products, breaking the paradigm of 3D printing as only a
prototyping or pre-production technique that has been the norm for many AM technologies. A
crossflow air-to-water heat exchanger (HX) was designed for manufacturing via fused filament
fabrication (FFF). Design iterations improved the manufacturability, considering issues such as
geometric fidelity, watertightness, print time, support material, and manufacturing cost. Carbon
fiber fillers enhanced the thermal conductivity of the base polyamide resin, allowing for thermal
HX performance comparable to conventional aluminum finned tube heat exchangers. The
anisotropic thermal conductivity impacts the heat exchanger performance. The design and
manufacturing challenges reveal additional routes to continued performance gains as the HX is
scaled up to an 8 kilowatt product.",,,,,,
"['Mohammed, Mazher Iqbal', 'Fay, Pearse']",2021-11-09T20:57:16Z,2021-11-09T20:57:16Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90163', 'http://dx.doi.org/10.26153/tsw/17084']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['splint', '3D printing', 'CAD', 'patient specific', 'FFF', 'polymer', 'orthotic']",Design and Additive Manufacturing of a Patient Specific Polymer Thumb Splint Concept,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e22cffa-852e-40b6-8911-95f7cf998882/download,University of Texas at Austin,"Traditionally, upper limb splints often fall short of being optimal with respect fit and patient
expectations, resulting in a lack of use and no treatment of the underlying condition. In this study we
address several current limitations and examine the feasibility of using 3D optical scanning, Computer
Aided Design (CAD) and low cost 3D printing as a tool to create more ergonomic and efficacious splints
for patients suffering from compromised musculature or trauma of the thumb. Optical scanning allows
for a non-invasive and rapid means to reproduce the surface topology of a person’s hand and this data
was used as the template for the device design. We explore the use of CAD to create a more
aesthetically pleasing and functional splint, enhancing both comfort and potential moisture release.
Finally, we demonstrate that low cost polymer printing can allow for rapid design evaluation and
production of a final, usable device.",,,,,,
"['Yaple, Jordan', 'Noe, Cameron', 'Alenezi, Abdulmajeed', 'Phelan, Patrick', 'Bhate, Dhruv']",2023-02-10T13:59:34Z,2023-02-10T13:59:34Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117448', 'http://dx.doi.org/10.26153/tsw/44329']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Design and Additive Manufacturing of Bio-Inspired Copper Heat Sinks for Microelectronics Cooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/502b78b4-f695-4ddd-9f7c-70bb0bb5961c/download,,"The heat sink is a key component in thermal management of microelectronics and is 
traditionally designed with arrays of pins or fins. In this work, a bio-inspired approach to designing 
heat sinks was evaluated. A process was first developed on a 100W Laser Powder Bed Fusion 
(LPBF) system for the copper alloy CuNi2SiCr, which was found to have a tenfold deficit in 
thermal conductivity relative to commercially pure Copper. This process was then used to fabricate 
four heat sinks: two replicates of commercial heat sink designs, and two leveraging bio-inspired 
design approaches with the aim of increasing the available surface area per unit volume. The four 
designs were tested on a microelectronics package placed on a hot plate and their performance 
compared against commercially available heat sinks. The results demonstrated that despite their 
poor thermal conductivity, the bio-inspired heat sinks had equivalent performance to the 
commercial heat sinks.",,,,,,
"['Carbonell, R.M.', 'Crawford, R.H.']",2023-04-05T17:15:41Z,2023-04-05T17:15:41Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117781', 'http://dx.doi.org/10.26153/tsw/44660']",eng,2022 International Solid Freeform Fabrication Symposium,Open,gait,Design and Analysis of a Topology Optimized Transtibial Prosthetic Socket Using Combined Static Gait Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/682d029d-e429-47da-9a47-0941931bb2b7/download,,"This paper presents the design and analysis of an optimized transtibial prosthetic socket 
developed using the ground structure method of topology optimization (GSM). The socket wall 
between the distal 25% of the original socket and a proximal brim is replaced with an optimized 
truss geometry and a thin wall (1 mm). Separate trusses are developed for the loading conditions 
of three critical stances: heel strike, vertical (standing), and toe-off. The truss models are combined 
with critical components to create the final design. The proposed socket is 81.58% of the original 
socket volume and is designed for manufacturing using Selective Laser Sintering (SLS) and nylon-
12. The socket design is analyzed, with the material properties for sintered nylon-12, at 10% 
increments between heel strike and toe-off to determine the viability of both the socket and the 
corresponding methodology. Simulation results indicate that the design exceeds requirements for 
all tested stances.",,,,,,
"['Faustini, Mario', 'Crawford, Richard', 'Neptune, Richard R.', 'Rogers, William', 'Gitter, Andrew', 'Bosker, Gordon']",2019-11-21T17:50:57Z,2019-11-21T17:50:57Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78544', 'http://dx.doi.org/10.26153/tsw/5600']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Duraform/SLS,Design and Analysis of Orthogonally Compliant Features for DuraForm/SLS Manufactured Plates,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a99d8f4-a95a-49c5-9828-60022a0363d3/download,,"In many applications of parts manufactured by Solid Freeform Fabrication (SFF), compliance is
an important factor. In order to achieve given deformation goals with optimal shape, the design
of compliant mechanisms and elements fabricated with SFF techniques must take into account
the particular constraints and boundary conditions of the target application as well as the specific
material properties of the part. The present work focuses on the design and evaluation of
compliant features for a geometrically constrained thin-wall part subject to loads normal to its
tangent plane. Such features would need to be embedded in the object. The manufacture of
prosthetic sockets for lower-limb amputees is the specific application presented, where greater
compliance is needed at sites in contact with pressure sensitive tissues. Sample parts were
fabricated by selective laser sintering, and the material used was Duraform.","The authors gratefully acknowledge financial support for this work from the VA Rehabilitation
Research and Development Service.",,,,,
"['Meisel, Nicholas A.', 'Williams, Christopher B.']",2021-10-12T19:01:48Z,2021-10-12T19:01:48Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88722', 'http://dx.doi.org/10.26153/tsw/15656']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'material extrusion', 'vending machine', 'informal learning']",Design and Assessment of an AM Vending Machine for Student Use,Conference paper,https://repositories.lib.utexas.edu//bitstreams/754ef7e2-e036-42b3-945d-a5632745e709/download,University of Texas at Austin,"Due to prohibitive costs, access to Additive Manufacturing (AM) technologies at academic
institutions tends to be limited to upper-level courses that feature significant project-based
coursework, such as capstone design. However, with the decreasing cost of desktop-scale AM
technology, there is potential to improve student access to such technologies throughout a
student’s undergraduate career, and thus provide more opportunities for AM education. In this
poster, the authors present the design and implementation of an AM “vending machine” that is
powered by desktop-scale extrusion-based AM systems. The resulting machine allows for
unrestricted student use of AM equipment, and thus provides ample opportunity for informal
learning regarding AM. The results of a formal assessment of student use of the machine are
presented.",,,,,,
"['Yang, L.', 'Harrysson, O.', 'West, H. II', 'Cormier, D.']",2021-10-05T13:38:43Z,2021-10-05T13:38:43Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88369', 'http://dx.doi.org/10.26153/tsw/15308']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['electron beam melting', 'auxetic structures', 'Ti6Al4V', 'copper']",Design and Characterization of Orthotropic Re-Entrant Auxetic Structures Made via EBM Using Ti6Al4V and Pure Copper,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b0f48ff-c5e6-4f88-8fec-9b282bc660b9/download,University of Texas at Austin,"An orthotropic 3D re-entrant honeycomb structure that exhibits a negative Poisson’s ratio
was designed and fabricated via the electron beam melting (EBM) process. The modeling work
established the relationships between various structural parameters and the mechanical properties
of the auxetic structures. Compressive tests were performed on the re-entrant honeycomb
samples made with Ti6Al4V as well as pure copper. Results of the strength, modulus and energy
absorption for the two materials were compared with the theoretical models in order to verify the
theoretical predictions.",,,,,,
"['Grossman, James', 'Parad, Warren', 'Lipson, Hod']",2021-09-28T18:51:33Z,2021-09-28T18:51:33Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88152', 'http://dx.doi.org/10.26153/tsw/15093']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['freeform fabricator', 'six degree of freedom', 'fabrication design', 'fabrication construction']",Design and Construction of a 6-DoF Fabrication Platform,Conference paper,https://repositories.lib.utexas.edu//bitstreams/137e1018-cf28-4d29-b51d-3cee6479bb08/download,University of Texas at Austin,"This research demonstrates a working freeform fabricator with a six degree of freedom printhead capable of additive fabrication onto existing structures. A parallel actuation mechanism was
developed with stationary motors. Kinematic simulations of the printer’s motion were used to
analyze and optimize the design. The components of the printer are described, including the
control system and print head mechanism. A working fabricator was then constructed and tested.
An additive three dimensional structure is demonstrated and the accuracy and reliability of the
printer is analyzed.",,,,,,
"['Daruwala, Darius P.', 'Johnson, Christopher M.', 'Jacobsen, Donald R.']",2018-11-29T20:22:35Z,2018-11-29T20:22:35Z,1997,Mechanical Engineering,doi:10.15781/T21834N7T,http://hdl.handle.net/2152/70339,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['endoscopic', 'Tomography']",The Design and Construction of a Medical System to Optimize the Endoscopic Ultrasound Procedure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ae3b8c5-8946-445e-8254-6ddf47cd7b42/download,,"This project involved the use ofrapid prototyping to produce a model of a section ofthe
gastrointestinal (GI) tract which could be used for practice ofthe Endoscopic Ultrasound (EUS)
procedure.
Computed Tomography (CT) scans were obtained from Dr. Donald Jacobsen, Assistant
Professor ofRadiology at the Medical College ofWisconsin in Milwaukee. Apart from the final
testing, the entire project was performed at the Milwaukee School ofEngineering's Rapid
Prototyping Center. To convert the CT scans into files that are compatible with the rapid
prototyping machines, a software developed by Materialise, N.V., was used. The rapid prototype
models were used as master patterns for molds so that a polyurethane material with similar
properties to human tissue could be used for actual simulation. Finally, these polyurethane
models were placed in an enclosure and surrounded by a gelatin to simulate fatty abdominal
tissue. The system was tested at Froedtert Memorial Lutheran Hospital under the supervision of
Dr. Anthony Bohorfoush in conjunction with the Medical Physics Department ofthe Medical
College ofWisconsin.",,,,,,
"['Wagner, Grady W.', 'Bass, Lindsey B.', 'Rau, Daniel A.', 'Ziv, Scott B.', 'Wolf, Mitchell S.', 'Wolf, David L.', 'Meenakshisundaram, Viswanath', 'Williams, Christopher B.']",2021-11-04T18:44:55Z,2021-11-04T18:44:55Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90001', 'http://dx.doi.org/10.26153/16922']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['multi-tool additive manufacturing', 'additive manufacturing', 'design and development']",Design and Development of a Multi-Tool Additive Manufacturing System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ae712bef-de1d-43ba-b687-780ca0af3476/download,University of Texas at Austin,"Additive manufacturing (AM) makes complex parts with a single class of material. Each
AM technology encompasses specific techniques and requires diverse components to selectively
form each layer, which has segregated AM research by respective technologies. Multimaterial
AM exists, but it is the same class of material with the same deposition tool. To fully benefit
from AM, researchers must explore the combination of multiple AM modalities and materials
such that a multifunctional part may be fabricated using strengths of multiple
technologies. While the methods for fabricating each layer differ, all of the AM technologies
share the fundamental layer-based approach. By recognizing this universal similarity coupled
with the desire to make multifunctional parts, a single system has been created to combine five
different AM modalities. In this paper, the authors discuss the design and development of a
multi-tool AM system that includes binder jetting, material jetting, vat photopolymerization,
paste extrusion, and filament extrusion. Examples of multifunctional, multimaterial parts
fabricated by multiple AM processes in a single integrated process are demonstrated.",,,,,,
"['Chen, T.', 'Mueller, J.', 'Shea, K.']",2021-11-01T21:04:58Z,2021-11-01T21:04:58Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89751,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['bistable unit actuators', 'Von Mises Truss', 'bistability', 'material stiffness', 'multi-material additive manufacturing', 'additive manufacturing']",Design and Fabrication of a Bistable Unit Actuator with Multi-Material Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/81c616cc-c0b0-48f4-872f-27f896fa7156/download,University of Texas at Austin,"Bistable systems have two stable equilibrium states around which they can be perturbed.
Bistability in a mechanical system requires large deformation, which is commonly accommodated
by means of springs or soft joints. In this paper, the authors leverage the ability of advanced
Additive Manufacturing (AM) technology that enables printing of materials of varying stiffness
values to design and fabricate monolithic bistable unit actuators that maximize the stroke length.
A Von Mises Truss (VMT) based bistable structure utilizing snap-through buckling behavior is
designed and fabricated. By varying the material stiffness and length of the joints, the authors
are able to adjust the activation forces while keeping the geometry constant. 56 specimens are
fabricated and tested in tension and compression. Numerical simulation models are constructed
and the results are found to correlate well with experimental data. The required activation force
can be increased with a decrease in joint length or an increase in joint material stiffness.",,,,,,
"['Gervasi, Vito R.', 'Stahl, Douglas C.']",2020-02-20T18:42:26Z,2020-02-20T18:42:26Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80039', 'http://dx.doi.org/10.26153/tsw/7061']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Design and Fabrication of Components with Optimized Lattice Microstructures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/57ce3517-e9c4-4e67-855e-07d4f38ddae2/download,,"The design and fabrication of components with optimized lattice microstructures is a new
approach to creating lightweight high-performance objects. This paper introduces a unique and
complete integration of design and fabrication leading to the creation of structural components
with complex composite microstructures. Rather than a solid cast component with optimized
outer shape this new approach leads to a component with an inner skeleton  or microstructure 
maximizing one or more properties such as the stiffness-to-weight ratio. Three dimensional
gradient materials are a natural outcome of this approach. An introduction to the design
optimization and hybrid fabrication approach will be provided in addition to research progress
and challenges through Spring 2004.",,,,,,
"['Sun, C.N.', 'Choy, S.Y.', 'Leong, K.F.', 'Wei, J.']",2021-11-01T22:28:47Z,2021-11-01T22:28:47Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89783,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['functionally graded components', 'gradient lattice strucutres', 'unit cells', 'selective laser melting']",Design and Fabrication of Functionally Graded Components by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/da42230d-b853-4c98-8cf5-cdedf0436122/download,University of Texas at Austin,"The control of structure formation of additive manufacturing simplifies the fabrication of functionally
graded components (FGC), which changes in the physical properties can be achieved via structural design. In
this research, selective laser melting (SLM) technology was used to fabricate structures with gradient lattice
designs. The structure was varied in strut thickness continuously and linearly in single direction for cubic and
honeycomb unit cells. Results showed that the complex design was successfully built and achieved nearly full-dense strut. Compression test results showed that the stress-strain curves of both cubic and honeycomb lattice
structures oscillate with multiple peak loads, suggesting ductile characteristics. However, lattice structures with
graded thickness tend to oscillate upward as the strut diameter increases.",,,,,,
"['Chen, Xueyang', 'Yan, Lei', 'Newkirk, Joe', 'Liou, Frank']",2021-11-02T14:05:52Z,2021-11-02T14:05:52Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89807,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['functionally graded material', 'laser metal deposition', 'crack-free', 'titanium', 'γ-TiAl', 'TiAl']",Design and Fabrication of Functionally Graded Material from Ti to γ-TiAl by Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba36dd0c-1e8d-4ad9-a8ce-9906142632a3/download,University of Texas at Austin,"Functionally graded material (FGM) is one kind of advanced material characterized by a
gradual change in properties as the position varies. The spatial variation of compositional and
microstructure over volume is aimed to control corresponding functional properties. In this
research, when 100% γ-TiAl was directly deposited on pure Ti substrate, cracks were formed
within the γ-TiAl layer. Then a six-layer crack-free functionally graded material of Ti/TiAl was
designed and fabricated by laser metal deposition (LMD) method, with composition changing from
pure Ti on one side to 100% γ-TiAl on the other side. The fabricated FGM was characterized for
material properties by a variety of techniques. The chemical compositions, microstructure, phases,
and hardness of the composite were characterized by Scanning Electronic Microscope (SEM),
Optical Microscope (OM), Energy Dispersive X-ray Spectroscopy (EDS), and hardness testing.
The microstructure and chemical compositions in different layers were studied.",,,,,,
"['Maheshwaraa, Uma', 'Tradd, Catherine', 'Bourell, David', 'Seepersad, Carolyn Conner']",2020-03-05T19:17:01Z,2020-03-05T19:17:01Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80144', 'http://dx.doi.org/10.26153/tsw/7165']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Design and Freeform Fabrication of Deployable Structures with Lattice Skins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e91e0586-e0a6-4955-9c78-72a97a8bc4d9/download,,"Frontier environments—such as battlefields, hostile territories, remote locations, or outer
space—drive the need for lightweight, deployable structures that can be stored in a compact
configuration and deployed quickly and easily in the field. We introduce the concept of lattice
skins to enable the design, solid freeform fabrication (SFF), and deployment of customizable
structures with nearly arbitrary surface profile and lightweight multi-functionality. Using
Duraform FLEX® material in a selective laser sintering machine, large deployable structures are
fabricated in a nominal build chamber by either virtually collapsing them into a condensed form
or decomposing them into smaller parts. Before fabrication, lattice sub-skins are added
strategically beneath the surface of the part. The lattices provide elastic energy for folding and
deploying the structure or constrain expansion upon application of internal air pressure. Nearly
arbitrary surface profiles are achievable and internal space is preserved for subsequent usage. In
this paper, we present the results of a set of experimental and computational models that are
designed to provide proof of concept for lattice skins as a deployment mechanism in SFF and to
demonstrate the effect of lattice structure on deployed shape.",,,,,,
"['Yeung, Ho', 'Hutchinson, Keely', 'Lin, Dong']",2021-12-07T18:05:42Z,2021-12-07T18:05:42Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90741', 'http://dx.doi.org/10.26153/tsw/17660']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['testbed control software', 'testbed', 'laser powder bed fusion', 'National Institute of Standards and Technology']",Design and Implementation of Laser Powder Bed Fusion Additive Manufacturing Testbed Control Software,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee547614-48d8-465e-9736-b66549830ca6/download,University of Texas at Austin,"The National Institute of Standards and Technology developed a facility titled the Additive
Manufacturing Metrology Testbed to advance the research in laser powder bed fusion (LPBF)
processes. The testbed adopted an open control architecture which allows full access to all key
process parameters. Although LPBF control is a very important topic, very little literature can be
found on how this is implemented. This paper reviews the testbed control software design and
implementation. Scan path planning, galvo motion control, and laser power control are detailed
with select highlights. Comparison with commercial machine control software is made, and recent
experiments utilizing the advanced features of the testbed control software are also discussed.",,,,,,
"['Abdullah, J. Laeng aka Jamaluddin', 'Liou, Frank', 'Mohamad Ibrahim, M.N.', 'Wan Muhammad, W.M.']",2019-09-25T16:19:48Z,2019-09-25T16:19:48Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76002', 'http://dx.doi.org/10.26153/tsw/3101']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Deposition,Design and Integration of a Laser-Based Materials Deposition System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bed4ba6e-c79c-4579-b98e-b74a09543b6b/download,,"This paper aims to demonstrate the design process of an integrated five-axis Laser-Based Material Deposition (LBMD) system for rapid prototyping application. Several design evaluation methods are selected and applied to the design of the system. A three-dimensional graphical simulation software package was used as a decision making aid and as an analysis tool
in the design process. Hardware integration of a five-axis computer numerical controlled (CNC) vertical milling machine, a 2.5 KW Nd:YAG laser and a linear table is discussed. A brief introduction to the system software and control architecture is also summarized. Some important design issues and considerations specific to Laser Based Material Deposition process are suggested.",,,,,,
"['Jayashankar, Dhileep Kumar', 'Devarajan, Aarthi', 'Dong, Guoying', 'Rosen, David']",2021-12-06T21:46:36Z,2021-12-06T21:46:36Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90683', 'http://dx.doi.org/10.26153/tsw/17602']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['UAV wing', 'topology optimization', 'fiber reinforced composites', 'material extrusion', 'design for additive manufacturing']",Design and Manufacture of a Continuous Fiber-Reinforced 3D Printed Unmanned Aerial Vehicle Win,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e2918b6c-f663-4fa3-b284-85f9f777b10b/download,University of Texas at Austin,"The Markforged Mark Two 3D printer is capable of printing various orientations of
continuous fiber reinforcement. An initial study of how the orientation of the fiber influences the
strength characteristics (tensile and flexural properties) was conducted. Four combinations of
carbon fiber reinforcement orientations were tested, specifically unidirectional, isotropic,
concentric and a combination of isotropic and concentric, with the Markforged Onyx matrix
material. The results will aid in designing a wing with the optimum fiber configuration that will
give the desired mechanical properties based on the forces acting on the wing. Design for Additive
Manufacturing (DfAM) concepts and tools will be used to design and manufacture a large UAV
wing. Topology optimization, based on a CFD computed pressure distribution, was used to
determine geometric regions where carbon fiber reinforcement could be best utilized. From there,
a honeycomb structure was designed to ensure stiffness and light weight based on desired densities.
A wing section was fabricated using the Mark Two printer to identify the capabilities and
limitations of the system in realizing the design objectives.",,,,,,
"['Ilardo, Ryan', 'Williams, Christopher B.']",2021-09-29T20:10:14Z,2021-09-29T20:10:14Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88209', 'http://dx.doi.org/10.26153/tsw/15150']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'intake manifold', 'formula SAE']",Design and Manufacture of a Formula SAE Intake System Using Fused Deposition Modeling and Fiber-Reinforced Composite Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f91454b9-1b3a-418c-b11f-eb1ce6c51c6c/download,University of Texas at Austin,"In this paper, the authors discuss the design and manufacture of an intake system for a 600cc Formula
SAE engine. Specifically, Fused Deposition Modeling is used to create an intake system (consisting of a
plenum, plenum elbow, and cylinder runners) that is then later covered in layers of carbon fiber composite
fabric through vacuum bagging. As a result of this approach, the geometry of the intake system has been
redesigned to result in reduced weight (due to lower material density and lack of welds, hose clamps, and
silicon couples), improved charge distribution, and increased torque through a wide RPM range when
compared to its traditionally-manufactured aluminum counterpart.",,,,,,
"['Burhan, Danny', 'Crawford, Richard']",2020-02-20T18:27:19Z,2020-02-20T18:27:19Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80035', 'http://dx.doi.org/10.26153/tsw/7057']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Design and Manufacture of an Attachment Fitting for Transtibial Prosthetic Sockets Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a61e61f4-66a4-4531-9b94-b34b28086c2e/download,,"The focus of this work is using selective laser sintering to manufacture transtibial
prosthetics sockets with compliant features to relieve contact pressure in sensitive areas. Each of
these sockets requires an integrated attachment fitting to connect to the pylon and foot using
standard hardware. Several design concepts of an attachment fitting are presented and
compared. The design concepts were tested using a tensile test machine and analyzed using
ground reaction force data to ensure a structurally sound connection. The resulting design
employs standard hardware while maintaining the integrity of the connection for a normal gait
cycle.",,,,,,
"['Horn, Timothy J.', 'Harrysson, Ola L.A.', 'Little, Jeffrey P.', 'West, Harvey A. Jr', 'Marcellin-Little, Denis J.']",2021-10-01T00:31:43Z,2021-10-01T00:31:43Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88310', 'http://dx.doi.org/10.26153/tsw/15251']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['orthopedic implants', 'cadaveric bone specimens', 'direct metal freeform fabrication', 'bone analog models']",Design and Manufacturing of Bone Analog Models for the Mechanical Evaluation of Custom Medical Implants,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e47b668b-9ec8-49dc-9b3b-3a2031a7840e/download,,"The performance of orthopedic implants is often evaluated using cadaveric bone
specimens. The high inter-specimen variability of cadaveric bone properties requires large
sample sizes to obtain statistical significance. With recent focus on custom implants
manufactured using direct metal freeform fabrication techniques, the need for a customized bone
analog model is recognized. Data for bone geometry and internal structure were obtained from
computed-tomography imaging. Traditional rapid prototyping techniques are then used to
generate the rapid tooling from which composite bones that mimic the properties of the real bone
can be duplicated. This work focused on the manufacturing process of bone analog models.",,,,,,
"['VanHorn, Austin', 'Zhou, Wenchao']",2021-10-19T21:24:55Z,2021-10-19T21:24:55Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89341,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['inkjet deposition', 'high temperature microheater', 'microheater', 'thermal inkjet', 'design', 'optimization']",Design and Optimization of a High Temperature Microheater for Inkjet Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7dfe7257-84f8-4dc4-a9be-1b2c9a47db2d/download,University of Texas at Austin,"Inkjet deposition has become a promising additive manufacturing technique due to its fast
printing speed, scalability, wide choice of materials, and compatibility for multi-material
printing. Among many different inkjet techniques, thermal inkjet, led by Hewlett-Packard and
Canon, is the most successful inkjet technique that uses a microheater to produce a pressure
pulse for ejecting droplets by vaporizing the ink materials in a timespan of microseconds.
Thermal inkjet has been widely adopted in many commercial 3D inkjet printers (e.g., 3D
Systems ProJet X60 series) due to its low cost, high resolution, and easy operation. However, the
viscosity of the printable materials has been limited to less than 40cP due to insufficient energy
provided inside the nozzle to overcome the viscous dissipation of energy. This paper presents a
study on the design and optimization of a high temperature microheater with a target heating
temperature of more than 600˚C (compared to ~300 ˚C for current printhead) to increase the
energy supply to the nozzle. The benefits are fourfold: 1) higher temperature will lead to faster
vaporization of ink and thus higher jetting frequency and print speed; 2) higher temperature will
make it possible for jetting materials with higher boiling points; 3) higher temperature will
reduce the viscosity of the ink and thus the viscous dissipation of energy; 4) higher energy
supply will increase the magnitude of the pressure pulse for printing more viscous materials. In
this paper, a high temperature microheater was designed with the following objectives: to reduce
thermal stress in heaters, and to minimize uneven heat distribution. A literature survey was first
conducted on design, fabrication, and operation of thin-film resistive microheaters. A
multiphysics numerical model was then developed to simulate electrical, thermal, and
mechanical responses of the microheater. The model was validated by comparison to
experimental data and existing models obtained from literature. With proper parameterization of
the design geometry, the geometry of the microheater is optimized using a particle swarm
optimization method. Results show the optimized high temperature microheater successfully
operates at temperatures in excess of 600˚C. The design optimization enabled better
characteristics for even heat distribution and minimizing stress. The design approach can serve as
a fundamental means of design optimization for microheaters.",,,,,,
"['Sinha, Swapnil', 'Rieger, Kelsey', 'Knochel, Aaron D.', 'Meisel, Nicholas A.']",2021-11-08T23:08:50Z,2021-11-08T23:08:50Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90072', 'http://dx.doi.org/10.26153/tsw/16993']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['deployable mobile makerspace', 'design', 'evaluation', 'additive manufacturing education', 'additive manufacturing', 'STEAM', 'education']",Design and Preliminary Evaluation of a Deployable Mobile Makerspace for Informal Additive Manufacturing Education,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5539075a-62ac-4410-8948-372e80c9c25c/download,University of Texas at Austin,"Additive Manufacturing (AM) has played an integral part in the growth of makerspaces as
democratization of manufacturing continues to evolve. AM has also shown potential in enabling
the successful amalgamation of art (A) with science, technology, engineering, and math (STEM)
disciplines, giving new possibilities to STEAM subjects and its implementation. This paper
presents the conceptual design and development of a deployable, mobile makerspace curriculum
focused on AM education for a diverse range of participant backgrounds, ages, and locations. The
aim is to identify effective means of informal learning to broaden participation and increase
engagement with STEAM subjects through the context of AM. The curriculum is envisioned as
“material-to-form,” offering separate modules that present opportunities for self-directed learning
through all the stages of design, material use, and manufacturing associated with AM. Pilot studies
of the curriculum were performed to identify potential changes to improve the effectiveness of the
mobile makerspace.",,,,,,
"['Handler, Evan', 'Sterling, Amanda', 'Pegues, Jonathan', 'Ozdes, Huseyin', 'Masoomi, Mohammad', 'Shamsaei, Nima', 'Thompson, Scott M.']",2021-11-08T22:42:55Z,2021-11-08T22:42:55Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90060', 'http://dx.doi.org/10.26153/tsw/16981']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'heat transfer equipment', 'heat exchangers', 'additive manufacturing']",Design and Process Considerations for Effective Additive Manufacturing of Heat Exchangers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a05b4e06-f8d8-4e1a-a07e-98211909d5bc/download,University of Texas at Austin,"This paper provides some insights into using powder bed fusion (PBF) techniques for
additively manufacturing heat transfer equipment (HTE), such as heat pipes and heat sinks.
Background information is provided on the operating principles of PBF and the subsequent
features of parts fabricated via PBF. Examples of heat transfer equipment produced using PBF
are discussed. Some benefits and challenges associated in using PBF for generating effective
heat transfer equipment are summarized.",,,,,,
"['Kubalak, Joseph R.', 'Mansfield, Craig D.', 'Pesek, Taylor H.', 'Snow, Zachary K.', 'Cottiss, Edward B.', 'Ebeling-Koning, Oliver D.', 'Price, Matthew G.', 'Traverso, Mark H.', 'Tichnell, L. David', 'Williams, Christopher B.', 'Wicks, Alfred L.']",2021-10-28T19:30:49Z,2021-10-28T19:30:49Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89676,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['material extrusion', 'additive manufacturing', '3D printing', 'industrial robot', 'out of plane deposition']",Design and Realization of a 6 Degree of Freedom Robotic Extrusion Platform,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e50a5111-44bd-4052-b88b-554a6e7af3cb/download,University of Texas at Austin,"The layer-wise deposition of Additive Manufacturing (AM) processes allows for significant
freedom in the design of product geometry; however, the use of 3-axis deposition tools results
in layer interfaces that reduce material properties in the build direction. Adding additional
degrees-of-freedom (DOF) to the AM tool could remove this limitation by enabling out of
plane material deposition. For example, multi-DOF tool paths could align material extrusion
with a part's stress contours to circumvent inter-layer delamination. As a step towards this
goal, the authors designed, fabricated, and tested an AM extrusion system that leverages a
6-DOF robotic arm. In this paper, the authors detail the realization of this system including
the design of a high-temperature filament extruder, kinematics and tool path generation,
and user interface. The performance of the system is evaluated through layered deposition
of ABS thermoplastic.",,,,,,
"['Velu, Rajkumar', 'Vaheed, Nahaad', 'Raspall, Felix']",2021-11-10T21:39:10Z,2021-11-10T21:39:10Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90184', 'http://dx.doi.org/10.26153/tsw/17105']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['molds', 'design', 'fabrication', 'production workflow', 'fiber placement', 'composites', '3D printing']",Design and Robotic Fabrication of 3D Printed Moulds for Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/af3ab220-3a4a-4a1e-9bd8-39c27a58c006/download,University of Texas at Austin,"3D printing technologies have a direct impact on manufacturing the composite structures and in
particularly fabrication of molds. Molds produced through additive manufacturing methods would
greatly improve product features. The material selection and process conditions involved for
producing mold tooling, mainly towards Automated fiber placement (AFP) work cells. In this
study, the main objective is to improve the design and fabrication of composite parts through
complex molds as well as to assess and improve the production workflow through the development
of an effective design environment for the existing fiber placement operation. A robotic arm will
be used to hold the print surface and to follow a pre-programmed print path with a stationary
extruder to fabricate the mold tooling. This paper will present a review on the selection process for
mold materials and the initial experimental work carried out to investigate required properties of
3D printed molds.",,,,,,
"['Felber, R.A.', 'Rudolph, N.', 'Nellis, G.F.']",2021-11-01T21:55:55Z,2021-11-01T21:55:55Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89770,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['material extrusion', 'conductive fillers', 'air-cooled heat exchangers', '3D printing', 'design', 'simulation']",Design and Simulation of 3D Printed Air-Cooled Heat Exchangers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/23a96a01-1152-4322-b5c4-e3366d7e7411/download,University of Texas at Austin,"The use of material extrusion with conductive fillers is explored for air-cooled heat
exchangers. A general overview of the manufacturing tasks, design criteria, printability
constraints, and modeling techniques is given, along with experimental data from prototype
testing. The first sub-scale prototype design is an air-water crossflow heat exchanger designed to
transfer around 100 Watts. It was printed with unfilled conventional ABS and the air channels
designed with an array of round pin fins to enhance heat transfer. The prototype was also CT-scanned for inspection of the printed pin fin shapes.",,,,,,
"['Bales, Brenin', 'Walker, Roo', 'Pokkalla, Deepak', 'Kim, Seokpum', 'Kunc, Vlastimil', 'Duty, Chad']",2023-01-27T14:10:24Z,2023-01-27T14:10:24Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117335', 'http://dx.doi.org/10.26153/tsw/44216']",eng,2022 International Solid Freeform Fabrication Symposium,Open,z-pinning,Design and Use of a Penetrating Deposition Nozzle for Z-Pinning Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a05372c9-76ca-4207-ac92-062ef2295e03/download,,"Fused Filament Fabrication (FFF) involves depositing material layer-by-layer to create a 
three-dimensional object. This method often demonstrates high mechanical anisotropy in the 
printed structure, leading to a drop in the material strength of the part when comparing structures 
along the deposition plane (X/Y-Axis) versus across layers in the build direction (Z-Axis). Initial 
efforts to improve anisotropy led to the development of the Z-Pinning process, where continuous 
pins are deposited across layers in the Z-Axis. Z-pinning has demonstrated significant gains in 
toughness and inter-layer strength, particularly in fiber-reinforced materials. However, this 
process can also create flaws in the structure that increase in severity and frequency as the pins 
grow in length and diameter. To mitigate this, a penetrating nozzle has been developed that 
extends a fine-tipped extrusion nozzle deep into the pin cavity and simultaneously extrudes 
material as it retracts. This study investigates the printability of the penetrating nozzle for simple 
geometries and evaluates the resulting Z-pinning mesostructure. As a result of this study, the 
prototype penetrating nozzle design was analyzed and built. Through a pressure driven flow 
analysis it was determined that filament will flow through the penetrating nozzle as the system 
pressure drop of 9.3 Mpa is less then the minimum critical pressure of 12.07 Mpa. Additionally, 
it was after a transient thermal simulation, it was found that after a pause of 15 seconds the 
system can resume printing with no drop in heat at nozzle exit. This means the additional length 
of the penetrating nozzle, will not cause any clogs during any pauses in filament flow.",,,,,,
"['Hiller, Jonathan D.', 'Lipson, Hod']",2021-09-28T19:55:01Z,2021-09-28T19:55:01Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88166', 'http://dx.doi.org/10.26153/tsw/15107']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['multi-material printing', 'autonomous design', 'freeform shapes', '3D non-uniform structures', '3D compliant actuators']",Design Automation for Multi-Material Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f966abd6-519e-4f0b-aef0-34f83c956f67/download,University of Texas at Austin,"The advent of multi-material freeform fabrication technologies has exponentially
increased the mechanical design space available to engineers. The feature-based
paradigm of traditional CAD software is insufficient to take advantage of the
freedom of internal material distribution and gradients. Here we present a flexible
evolutionary design algorithm for 3D multi-material structures that fully utilizes
this expanded design space. The material distribution is optimized subject to high
level functional constraints, or simple constraints such as maximizing stiffness per
weight. The algorithm is inherently capable of shape optimization, or can simply
optimize material distribution within a given geometry. We demonstrate
autonomous design of freeform shapes, 3D non-uniform structures, and 3D
compliant actuators.",,,,,,
"['Lambert, Phillip M.', 'Campaigne, Earl A. III', 'Williams, Christopher B.']",2021-10-07T15:38:19Z,2021-10-07T15:38:19Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88484', 'http://dx.doi.org/10.26153/tsw/15418']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['mask projection', 'microstereolithography', 'stereolithography', 'vat polymerization', 'morphological matrix', 'functional decomposition', 'system design', 'system analysis', 'literature review']",Design Considerations for Mask Projection Microstereolithography Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3d3c81d3-5bed-4bdc-bd62-2d97530f702f/download,University of Texas at Austin,"Mask projection microstereolithography (MPµSL) uses a dynamic mask and focusing optics
to digitally pattern UV light and selectively cure entire layers of photopolymer resin. These
systems have been shown to be capable of creating parts with features smaller than 10µm. In this
paper, the authors analyze existing MPµSL systems using functional decomposition. Within the
context of a morphological matrix, these systems’ design embodiment decisions are compared
and the resulting performance tradeoffs are quantified. These embodiment decisions include the
dynamic mask, UV light source, projection orientation, and supporting optics. The aim of this
work is to provide a design guide for the realization of future MPµSL systems.",,,,,,
"['Speirs, M.', 'Pyka, G.', 'Kruth, J.-P.', 'Luyten, J.', 'Schrooten, J.', 'Wevers, M.', 'Van Humbeeck, J.']",2021-10-18T21:17:38Z,2021-10-18T21:17:38Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89248,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'biomedical scaffolds', 'TiAl6V4', 'node modification', 'design modification']",Design Enhancement of Biomedical Scaffolds Made By Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d7576252-57a7-492b-8801-3025554a2b79/download,University of Texas at Austin,"Selective laser melting (SLM) is increasingly used to fabricate biomedical scaffolds.
However, the intrinsic specifications of the process such as laser spot size, layer thickness,
and particle size limit the production accuracy, altering the geometrical characteristics and
mechanical properties of the scaffolds. This work attempts to assess and improve the
mechanical properties of TiAl6V4 biomedical scaffolds by eliminating/modifying the sharp
and thin nodes (as the main source of stress concentrations and lowering the mechanical
properties). This is carried out through a gradual increase of the beam (strut) thickness around
the nodes where corresponding struts meet. The compression performance of these scaffolds
was assessed and compared to common examples (unaltered struts) and to scaffolds designed
with thicker struts in the centre of the beams (demonstrating the largest contrast). The findings
prove that the thickening of the nodal points improves the strain distribution while maintains
the mechanical properties at an identical solid volume fraction. This can be used to improve
the scaffold design by a gradual strut thickness (in a comparable volume fraction) for an
improved bio-mechanical performance.",,,,,,
"['Williams, Christopher B.', 'Seepersad, Carolyn Conner']",2021-10-05T15:43:21Z,2021-10-05T15:43:21Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88395', 'http://dx.doi.org/10.26153/tsw/15334']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'engineering education', 'design education']",Design for Additive Manufacturing Curriculum: A Problem- and Project-Based Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8f43b5e7-c71c-4f0d-925a-976b266ad044/download,University of Texas at Austin,"Additive manufacturing education is of key importance because unfamiliarity with AM
technologies is one of the barriers to its widespread adoption. In this paper, the authors describe
their efforts to address this need via an undergraduate/graduate course in Additive
Manufacturing. Their courses, offered at the University of Texas at Austin and Virginia Tech,
cover the science of AM as well as principles of “design for additive manufacturing.” The
courses use both problem-based and project-based pedagogies to present students with
opportunities to gain hands-on experience with the technologies of AM. Examples of project
activities are presented along with student feedback.",,,,,,
"['Pareek, Shrey', 'Sharma, Vaibhav', 'Rai, Rahul']",2021-10-13T21:07:50Z,2021-10-13T21:07:50Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88785', 'http://dx.doi.org/10.26153/tsw/15719']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['kinematic pairs', 'fused deposition modeling', '3D printing', 'additive manufacturing', 'revolute pair', 'prismatic pair', 'cylindrical pair']",Design for Additive Manufacturing of Kinematic Pairs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/092e7eee-db56-4bae-9428-cf4feccac5a3/download,University of Texas at Austin,"While additive manufacturing processes are better suited for fabrication of parts with complex
geometries, they face serious challenges whilst fabricating parts that require relative motion with
respect to each other. The primary challenge in additive manufacturing of mechanisms is
preventing the mating parts from bonding with each other during the fabrication process. In this
paper the authors investigate design and additive fabrication of kinematic pairs that can move
relative to each other. The paper outlines fabrication of kinematic pairs based on optimal
clearance value for three basic lower order kinematic pairs, viz. revolute pair, prismatic pair, and
cylindrical pair. Using empirical testing functional relationships between extractive force and
clearance, and between moment and clearance have been developed. These functional
relationships can be used by users to fabricate kinematic pairs using FDM based 3D printing
processes. The efficacy of the proposed approach is demonstrated on 3D printed kinematic pairs
and experimental validation studies.",,,,,,
"Rosen, David W.",2020-03-10T14:20:28Z,2020-03-10T14:20:28Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80208', 'http://dx.doi.org/10.26153/tsw/7227']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Additive Manufacturing,Design for Additive Manufacturing: A Method to Explore Unexplored Regions of the Design Space,Conference paper,https://repositories.lib.utexas.edu//bitstreams/161728ed-4841-4cb1-9c3e-1774854e7fb6/download,,"Additive Manufacturing (AM) technologies enable the fabrication of parts and devices that
are geometrically complex, have graded material compositions, and can be customized. To take
advantage of these capabilities, it is important to assist designers in exploring unexplored regions
of design spaces. We present a Design for Additive Manufacturing (DFAM) method that
encompasses conceptual design, process selection, later design stages, and design for
manufacturing. The method is based on the process-structure-property-behavior model that is
common in the materials design literature. A prototype CAD system is presented that embodies
the method. Manufacturable ELements (MELs) are proposed as an intermediate representation
for supporting the manufacturing related aspects of the method. Examples of cellular materials
are used to illustrate the DFAM method.",,,,,,
"['Meisel, Nicholas A.', 'Williams, Christopher B.']",2021-10-13T21:30:27Z,2021-10-13T21:30:27Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88786', 'http://dx.doi.org/10.26153/tsw/15720']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Design for Additive Manufacturing (DfAM)', 'PolyJet', '3D printing', 'multiple materials', 'material jetting']",Design for Additive Manufacturing: An Investigation of Key Manufacturing Considerations in Multi-Material PolyJet 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/643201f1-7a1e-43be-b06f-ed82cee02bf1/download,University of Texas at Austin,"The PolyJet material jetting process is uniquely qualified to create complex, multi-material structures.
However, there is currently a lack of understanding and characterization regarding important
manufacturing considerations to guide designers in their use of the PolyJet process. This paper
investigates key considerations necessary to ensure that proposed designs are manufacturable and that
part properties are appropriate for the intended use. Considerations included in this paper include 1)
minimum manufacturable feature size, 2) removal of support material from channels, 3) survivability of
small features during water jet cleaning, and 4) the maximum self-supporting angle of printed parts in the
absence of support material. The result of this work is an understanding of which geometric and process
variables affect these manufacturing considerations. This understanding is crucial for the creation of a set
of Design for Additive Manufacturing (DfAM) guidelines to help designers create ideal, manufacturable
parts with less iteration and provide constraints for insertion into automated design processes such as
topology optimization.",,,,,,
"['Kim, Samyeon', 'Tang, Yunlong', 'Rosen, David W.']",2021-11-16T15:33:23Z,2021-11-16T15:33:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90315', 'http://dx.doi.org/10.26153/tsw/17236']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['design for additive manufacturing', 'designers', 'part consolidation', 'part identification', 'lifecycle', 'additive manufacturing']",Design for Additive Manufacturing: Simplification of Product Architecture by Part Consolidation for the Lifecycle,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99ecbe19-7841-444d-9b9e-a2cdcdd83b67/download,University of Texas at Austin,"Additive manufacturing (AM) can support the fabrication of the complex design and generate new
design opportunities for improving products. To identify and leverage these opportunities, design studies in early
product design stages are required. Since part consolidation is one of AM design potentials in conceptual and
embodiment design stages, this study proposes a design method to reconceptualize existing product design in
the context of part consolidation. Function requirements and physical relations between existing parts are
used to investigate AM design potential and identify candidates for consolidation. After identification of
consolidation candidates, function sharing between parts and modules is checked because they have high
possibilities to be consolidated if they share the same functions. Furthermore, AM design potential is identified
to help designers add value in part design. In order to support designers, it is required to link AM design
potential to the part candidates in order to explore AM design benefits. A case study with motorcycles is
performed to demonstrate the proposed method. The AM design potential for the case study contains the
lifecycle considerations related to fuel savings due to lightweight, and simplified and less expensive assembly
operations due to simplified product architecture by part consolidation.",,,,,,
"['Yang, L.', 'Harrysson, O.L.A.', 'Cormier, D.', 'West, H.', 'Zhang, S.', 'Gong, H.', 'Stucker, B.']",2021-11-01T21:37:45Z,2021-11-01T21:37:45Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89762,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['lightweight structure', 'additive manufacturing', 'cellular structure', 'unit cell', 'design']",Design for Additively Manufactured Lightweight Structure: A Perspective,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c810ea68-8ab4-413d-a9ec-5064ab1a050f/download,University of Texas at Austin,"The design of lightweight structures realized via additive manufacturing has been drawing
considerable amount of attentions in academia and industries for a wide range of
applications. However, various challenges remain for AM lightweight structures to be
reliably used for these applications. For example, despite extensive advancement with
geometric design, there still lacks adequate understanding with the process-material
property relationship of AM lightweight structures. In addition, a more integrated design
approach must also be adopted in order to take non-uniform material design into
consideration. In our works, a design approach based on unit cell cellular structure was
taken in the attempt to establish a comprehensive design methodology for lightweight
structures. Analytical cellular models were established to provide computationally efficient
property estimation, and various design factors such as size effect, stress concentration and
joint angle effect were also investigated in order to provide additional design guidelines.
In addition, it was also found that the geometry and microstructure of the cellular structures
are dependent on both the process setup and the feature dimensions, which strongly support
the argument to establish a multi-scale hierarchical cellular design tool.",,,,,,
"['Palomino, Donald', 'McClelland, Ryan', 'Grau, Mike', 'Watkins, Ryan', 'Li, Bingbing']",2024-03-27T03:44:25Z,2024-03-27T03:44:25Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124473', 'https://doi.org/10.26153/tsw/51081']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['metal additive manufacturing', 'generative design', 'internal lattice structure']",DESIGN FOR INTERNAL LATTICE STRUCTURES WITH APPLICATION IN ADDITIVE MANUFACTURING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a17e7382-7a18-4580-861d-089f5d5de06c/download,University of Texas at Austin,"Internal lattice structures have the potential to significantly reduce the mass of an existing metal
component, which is a desirable characteristic in the aerospace and automobile industries.
However, there are still uncertainties on whether or not internal lattice structures can outperform
a solid version of the same mass. Additionally, internal lattice structures can only be produced
via additive manufacturing methods, bringing more challenges to resolve. To determine the
viability of internal lattice structures, a study will be performed to compare its performance with
solid, hollow, and mass penalty designs of equivalent masses using Autodesk Fusion 360. A
performance baseline will be established by running multiple simulations on simple geometries
to obtain the maximum displacement, first four modes, and first buckling mode. A generative
design part, better known within NASA Goddard Space Flight Center as A15, will undergo the
same simulations and have its results analyzed to determine feasibility.",,,,,,
"['Jahnke, U.', 'Koch, R.', 'Oppermann, A.T.']",2021-11-08T21:31:31Z,2021-11-08T21:31:31Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90046', 'http://dx.doi.org/10.26153/tsw/16967']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['product piracy', 'design for protection', 'protective measures', 'product development', 'additive manufacturing']",Design for Protection: Systematic Approach to Prevent Product Piracy During Product Development Using AM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e66a82cd-50c6-48b5-8fd5-1ec3a0409ed3/download,University of Texas at Austin,"Although infringements of intellectual properties in terms of product piracy are growing
for years and threaten investments in research and development most companies still rely on
legal measures like property rights. A more preventive effect to protect against counterfeits can
be achieved using technical measures complicating reverse engineering, improving traceability
and assuring data protection. Additive Manufacturing can contribute a lot to the effectivity and
efficiency of those technical measures but presently they are often unconsidered during product
development. To support decision makers and designers through all the steps of a product
development process an integrated systematic approach has been developed. Protective
measures using AM are allocated to specific process steps and responsible persons in charge so
that the result is a guideline for “design for protection”. The main idea is to help developing
piracy-robust products for that the return of investment is not threatened by counterfeits and its
economical impacts.",,,,,,
"Rosen, David W.",2021-12-01T21:16:35Z,2021-12-01T21:16:35Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90615', 'http://dx.doi.org/10.26153/tsw/17534']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['design for additive manufacturing', 'manufacturing process chain', 'process chain map']",Design for the Additive Manufacturing Process Chain,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bcb70654-7a12-411f-932b-7743d07fe4d9/download,University of Texas at Austin,"Post-processing operations are required for most additive manufacturing (AM) processes. For production
parts, consideration of these post-processing operations during design is critical to achieve design
requirements. For both metal and polymer parts, the sequence of steps in the process chain can be extensive.
A design framework called the Process Chain Map (PCM) is introduced in this paper that explicitly relates
design requirements for the part to each step in the AM process chain. This PCM visually shows the role
of each step in the process chain and facilitates communication among design and manufacturing personnel.
Software implementation of the PCM enables generation of system-level problem formulations of
multidisciplinary design optimization problems. An example of a metal AM part demonstrates the PCM
and the formulation of such a design problem.",,,,,,
"Meisel, Nicholas",2024-03-27T16:08:38Z,2024-03-27T16:08:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124502', 'https://doi.org/10.26153/tsw/51110']",en,2022 International Solid Freeform Fabrication Symposium,Open,"['problem-based learning', 'design for additive manufacturing', 'DfAM']",DESIGN FOR(E!) ADDITIVE MANUFACTURING: IN SEARCH OF A COMPREHENSIVE DESIGN CHALLENGE SUITABLE ACROSS AM EDUCATION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ca1242ac-8a34-4f3d-ba5e-6842edeeea7c/download,University of Texas at Austin,"Modern engineering design education relies heavily on the concept of problem-based learning
(PBL). Driven by the constructivist theory of education, PBL enables students to build
knowledge organically, rather than through rote memorization. As such, design for additive
manufacturing (DfAM) education also tends to emphasize the use of PBL to encourage student
learning. Unfortunately, dedicated DfAM education is still nascent. The result is a wide range of
educators leveraging an equally wide, and often unproven, range of design challenges to support
DfAM PBL. Because of this, there is the possibility that a chosen design challenge will not
represent AM as a true end-use manufacturing process nor promote a design space that can
benefit from the full consideration of all opportunistic and restrictive DfAM concepts. In this
paper, the author discusses the creation and implementation of a comprehensive design challenge
that is suitable across the range of AM education. Specifically, the author proposes the use of a
golf putter DfAM design challenge. This concept draws from lessons learned over years of
DfAM instruction at undergraduate and graduate levels and is based in the need for three key
aspects for a successful DfAM challenge in education: (1) clarity, (2) applicability, and (3)
demonstrability.",,,,,,
"['Lammers, S.', 'Tominski, J.', 'Magerkohl, S.', 'Künneke, T.', 'Lieneke, T.', 'Zimmer, D.']",2021-11-09T19:11:35Z,2021-11-09T19:11:35Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90132', 'http://dx.doi.org/10.26153/tsw/17053']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['design guidelines', 'software algorithm', 'design check', 'robust production', 'additive manufacturing']",Design Guidelines for a Software-Supported Adaptation of Additively Manufactured Components with Regard to a Robust Production,Conference paper,https://repositories.lib.utexas.edu//bitstreams/35eb7f98-3cc9-4426-a406-f4d8b43b21cc/download,University of Texas at Austin,"The design of additively manufactured components requires a rethinking in the design
process. This is inhibited by a lack of knowledge about additive manufacturing technologies.
For this reason, a large number of design guidelines have been developed in recent years. In
their present form the design guidelines are not suitable for processing in a software algorithm,
since the guidelines have a certain redundancy and partly influence each other. This paper
describes several steps to consolidate the existing guidelines and to prepare them in a way that
they can be used in a software algorithm for a design check. Therefore, existing guidelines are
collected, prioritized and quantified with regard to their relevance for a robust production. To
quantify the guidelines, test specimens are developed, produced and evaluated in order to obtain
a limit value for the geometric properties. With these limit values, quantifiable design
guidelines can be applied to designers and software tools.",,,,,,
"['Hassani, Vahid', 'Rosen, David W.', 'Goh, Ethan', 'Sarwan, Sufiyan', 'Doetzer, Florian']",2021-11-30T20:25:10Z,2021-11-30T20:25:10Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90536', 'http://dx.doi.org/10.26153/tsw/17455']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['fiber-reinforced composites', 'additive manufacturing', 'synergies', 'design method']",A Design Method to Exploit Synergies Between Fiber-Reinforce Composites and Additive Manufactured Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f753b450-9bd2-4a07-b805-38011bb929d8/download,University of Texas at Austin,"This paper proposes a design method for devices composed of long fiber-reinforced composites
(FRC) and additive manufactured (AM) parts. Both FRC and AM processes have similar application
characteristics: suitable for small production volumes, additive in nature, and capable of being highly
automated. On the other hand, the classes have distinct characteristics. FRC components tend to be large
and of simple shapes, while AM components tend to be small with highly complex geometry. Their
combination has the potential for significant synergies, while mitigating their individual limitations. A
decision guide is proposed, in the form of a series of questions, to guide the designer to determine if their
application is a good candidate for FRC+AM. The decision guide is reformulated into a proposed design
process that guides the designer to advantageously benefit from AM and FRC characteristics. The tools
are illustrated with an example of a composite pressure vessel with integrated pressure reducer.",,,,,,
"['Singh, Prabhjot', 'Moon, Yong-Mo', 'Dutta, Debasish', 'Kota, Sridhar']",2019-11-20T16:37:51Z,2019-11-20T16:37:51Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78477', 'http://dx.doi.org/10.26153/tsw/5562']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Multi-Directional,Design of a Customized Multi-Directional Layered Deposition System Based on Part Geometry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2fd149b1-01b4-4d7b-b7b2-681c51c9f8dd/download,,"Multi-Direction Layered Deposition (MDLD) reduces the need for supports by depositing
on a part along multiple directions. This requires the design of a new mechanism to reorient the part, such that the deposition head can approach from different orientations.
We present a customized compliant parallel kinematic machine design configured to
deposit a set of part geometries. Relationships between the process planning for the
MDLD of a part geometry and considerations in the design of the customized machine
mechanism are illustrated. MDLD process planning is based on progressive part
decomposition and kinematic machine design uses dual number algebra and screw
theory.",,,,,,
"['Chang, Yu-Chuen', 'Crawford, Richard H.']",2021-11-04T14:53:59Z,2021-11-04T14:53:59Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89976,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['desktop wire-feed prototyping machine', 'desktop prototyping machine', 'wire processing', 'wire melting', 'additive manufacturing']",Design of a Desktop Wire-Feed Prototyping Machine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/614dc808-7fc8-44f1-87ec-7ea4666cb8dc/download,University of Texas at Austin,"Much additive manufacturing research focuses on systems suitable for industrial
applications, especially research on metal processing. Our research aims to design a desktop-scale
prototyping machine to process metal wire. Possible applications for this research include various
wire structures, such as wire sculptures.
The wire joining technology is the most important subsystem of the envisioned layer-based
process. In this research, three concepts are proposed and analyzed according to the power required
to fully melt the wire. The selected approach uses a wire bender to create the desired geometry of
the product, and a pulse TIG welder to join the metal wire to retain the shape. Experiments were
conducted to evaluate the joining strength of pulse TIG welds to verify the joining efficiency of
the method. The experimental results indicate that filler metal is required to produce acceptable
welding strength. A conceptual CAD model of the complete system is presented.",,,,,,
"['Wang, Hongqing Vincent', 'Johnston, Scott R.', 'Rosen, David W.']",2020-02-27T20:27:17Z,2020-02-27T20:27:17Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80101', 'http://dx.doi.org/10.26153/tsw/7122']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Unit Truss,Design of a Graded Cellular Structure for an Acetabular Hip Replacement Component,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2a30b2a-ee83-4610-b12b-6c2947bee12f/download,,"The state-of-the-art porous coatings become more and more popular in uncemented prostheses
to make bone grow into implants for biological fixation. In this paper, graded cellular structures are
proposed for uncemented prostheses to enhance stability on implant-bone interfaces. As an example
study, the authors develop a new acetabular implant with gradient porosity for hip replacement. A
gradient porous acetabular component with cellular structure could match the bone’s elasticity.
Material is adaptively distributed from high porosity at the bone-implant interface to solid metal at the
joint’s articulating surface. The new acetabular prosthesis would replace metal-on-polyethylene
bearing with metal-on-metal bearing for less wear. The design problem of acetabular component is
formulated and a requirement list is elaborated. A detailed design of the prosthesis with a graded
cellular structure is presented. The design concept is validated with a comparison to the existing
products according to the design requirements.",,,,,,
"['McWilliams, John', 'Hysinger, Christopher', 'Beaman, J.J.']",2018-04-19T17:03:27Z,2018-04-19T17:03:27Z,1992,Mechanical Engineering,doi:10.15781/T26H4D72P,http://hdl.handle.net/2152/64384,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'HTW', 'process chamber']",Design of a High Temperature Process Chamber for the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7d0ae54d-962a-482d-af0c-9ceab1392361/download,,,,,,,,
"['Das, Suman', 'McWilliam, John', 'Wu, Benny', 'Beaman, J.J.']",2018-04-17T16:48:36Z,2018-04-17T16:48:36Z,1991,Mechanical Engineering,doi:10.15781/T2SN01N0P,http://hdl.handle.net/2152/64332,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'Selective Layer Sintering', 'SLS', 'High temperature workstation', 'HTW']",Design of a High Temperature Workstation for the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee46c425-aadf-49c8-b7d5-d5145a69a808/download,,,,,,,,
"['Das, Suman', 'Santosa, James']",2019-10-09T16:31:35Z,2019-10-09T16:31:35Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76159', 'http://dx.doi.org/10.26153/tsw/3248']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Deposition,Design of a Micro-Hopper Array for Multi-Material Powder Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f6f7961-e8e9-43be-85db-c113e6f4a0f5/download,,"We present a concept for creating patterned beds of multi-material powder particles using
an array of small-scale hoppers. Using this technique, we propose that to place fine particles of
multiple fluidized powders discretely in a thin layer as opposed to depositing an entire powder
layer of uniform composition using a roller device or doctor blade. Processing and consolidation
of multiple, patterned powders can enable fabrication of composite objects with spatially varying
structural and multifunctional characteristics. Although theory on the design of small-scale
hoppers is lacking, our design for a hopper, its valving, and its particle delivery system are
guided by background theory for large hoppers. A hopper array configuration is proposed, and a
calculation for deposition time is presented. Delivery of powder was achieved on a prototype
hopper. Experimentally measured mass flow rates were used to justify the use of this hopper with
SLS and to guide further design improvements.",,,,,,
"['Roy, Nilabh K.', 'Foong, Chee S.', 'Cullinan, Michael A.']",2021-10-28T20:20:24Z,2021-10-28T20:20:24Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89689,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['microscale selective laser sintering', 'µ-SLS', 'feature-size resolution']",Design of a Micro-scale Selective Laser Sintering System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d6c1ec2-2ee9-40bb-adb9-dd6e4676d104/download,University of Texas at Austin,"Micro and nanoscale additive manufacturing methods employing metals and ceramics have
many promising applications in the aerospace, medical device, and electronics industries.
However, the present state of art metal additive manufacturing tools have feature-size
resolutions of greater than 100 µm, which is too large to precisely control the geometrical
and dimensional aspects of the parts they produce. The weakness is particularly profound
in application of additive manufacturing to the fabrication of fine pitch interconnects in the
packaging and assembly of integrated circuits. A new microscale selective laser sintering
(µ-SLS) is being developed in this research to improve the minimum feature-size resolution
of metal additively manufactured parts by up to two orders of magnitude, while still
maintaining the throughput of traditional additive manufacturing processes. This paper
presents a detailed design of the sub-assemblies of the µ-SLS system including innovative
design features such as the use of (1) ultra-fast lasers, (2) a micro-mirror based optical
system, (3) nanoscale particles, (4) a precision spreader mechanism, (5) long-range
precision XY nano-positioner and (6) a global positioner.",,,,,,
"['Thissell, W.Richards', 'Tompkins, James', 'Marcus, Harris L.']",2018-04-10T17:05:44Z,2018-04-10T17:05:44Z,1990,Mechanical Engineering,doi:10.15781/T2C24R501,http://hdl.handle.net/2152/64237,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'Center for Materials Science and Engineering', 'SFF', 'CAD', 'Computer aided designs']",Design of a Solid Freeform Fabrication Diamond Reactor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7627b3f-d701-44d5-8bf6-2e6347946644/download,,"Solid Freeform Fabrication (SFF) has progressed from the visualization aided
stage of computer aided designs (CAD) to rapid prototyping of structural parts.
Among the promising techniques for producing structural prototypes is the technology
ofchemical vapor deposition (CVD) ofpolycrystalline diamond. This paper
discusses the thermodynamic and kinetic theories that suggest that structural
diamond may be rapidly deposited at rates approaching 1 mmJhr from the vapor
phase at metastable thermodynamic conditions. The design of a reactor that will
produce structural diamond prototypes is discussed. This reactor combines downstream
microwave plasma enhanced chemical vapor deposition (DMWPECVD)
with a scanned CO2 laser that locally heats the substrate to diamond deposition
temperatures. The input:Fases are H2, 02' CH4, and Ar. The operating pressure range
of the reactor is 1 x 10- to 7 x 102 Torr. The reactor is designed for in situ determination
of deposit thickness while deposition occurs as well as having the capacity
of fitting on an existing resonance enhanced multiphoton ionization time of flight
mass spectroscopy (REMPITOFMS) apparatus that will allow for plasma diagnostics
immediately above the heated substrate. Plasma diagnostics will be
employed to determine the active metastable species that results in diamond
deposition so that optimization can be made ofthe operating parameters to maximize
diamond selectivity and deposition rate.",,,,,,
"['Martina, Filomeno', 'Williams, Stewart W.', 'Colegrove, Paul']",2021-10-11T22:07:00Z,2021-10-11T22:07:00Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88661', 'http://dx.doi.org/10.26153/tsw/15595']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['wire + arc additive manufacturing', 'pulsed tungsten inert gas', 'process parameters', 'deposition parameters', 'Ti-6Al-4V']",Design of an Empirical Process Model and Algorithm for the Tungsten Inert Gas Wire+Arc Additive Manufacture of Ti-6Al-4V Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ba5f47c-89e4-4ffb-a3a5-c778128ce1f9/download,University of Texas at Austin,"In the wire+arc additive manufacture process parameters can be varied to achieve a wide range
of deposit widths, as well as layer heights. Pulsed Tungsten Inert Gas was chosen as the deposition
process. A working envelope was developed, which ensures unfeasible parameters combinations
are excluded from the algorithm. Thanks to an extensive use of a statistically designed experiment,
it was possible to produce process equations through linear regression, for both wall width and
layer height. These equations are extremely useful for automating the process and reducing the
buy-to-fly ratio. For a given layer height process parameters can be selected to achieve the required
layer width while maximising productivity.",,,,,,
"['Yang, Li', 'Harrysson, Ola', 'Cormier, Denis', 'West, Harvey', 'Park, Chun', 'Peters, Kara']",2021-10-12T18:20:39Z,2021-10-12T18:20:39Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88713', 'http://dx.doi.org/10.26153/tsw/15647']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['auxetic sandwich structures', 'cellular sandwich structures', 'auxetic cores', 'structural applications', 'electron beam melting', 'selective laser sintering']",Design of Auxetic Sandwich Panels for Structural Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e0de36c8-4cf8-4afb-a8cf-f657519d149b/download,University of Texas at Austin,"Based on an analytical modeling analysis, a sandwich structure with a 3D re-entrant
auxetic core was designed. Auxetic samples were produced by electron beam melting (EBM) and
selective laser sintering (SLS), and compared to other regular cellular sandwich structures
through various experiments. It was shown that sandwich structures with pre-designed auxetic
cores could exhibit significantly improved mechanical properties such as bending compliance
and energy absorption, which are critical to many structural applications. This work
demonstrated an alternative of effectively designing 3D cellular structures, and also showed the
potential of this type of auxetic structure in applications via careful design.",,,,,,
"['Philip, Ravi', 'Sparks, Todd E.', 'Liou, Frank']",2020-03-09T13:34:31Z,2020-03-09T13:34:31Z,8/27/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80174', 'http://dx.doi.org/10.26153/tsw/7193']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Laser Deposition,Design of Embedded Resistance Heating Element Using Rapid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2e20fbe-bfd3-49f5-bf92-29f3c6c6922b/download,,,,,,,,
"['Wallace, T. A.', 'Bey, K. S.', 'Taminger, K.M.B.', 'Hafley, R. A.']",2020-02-12T15:23:25Z,2020-02-12T15:23:25Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79936', 'http://dx.doi.org/10.26153/tsw/6962']",,2004 International Solid Freeform Fabrication Symposium,Open,Microstructure,A Design of Experiments Approach Defining the Relationships Between Processing and Microstructure for Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8bff84f5-af99-4bfc-90e0-edb7eb493d78/download,,,,,,,,
"['Quintana, Rolando', 'Puebla, Karina', 'Wicker, Ryan']",2020-03-09T15:29:14Z,2020-03-09T15:29:14Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80199', 'http://dx.doi.org/10.26153/tsw/7218']",eng,2007 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,Design of Experiments Approach for Statistical Classification of Stereolithography Manufacturing Build Parameters: Effects of Build Orientation on Mechanical Properties for ASTM D-638 Type I Tensile Test Specimens of DSM Somos® 11120 Resin,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9d2b3fe-0760-4bf0-91a9-28aa772da300/download,,"A statistical design of experiments (DOE) approach was used to determine if specific build
orientation parameters impacted mechanical strength of fabricated parts. A single platform (10-
inch by 10 inch cross-section) on the 3D Systems Viper si2 machine was designed to hold 18,
ASTM D-638 Type I samples built in six different orientations (called Location) with three
samples built for each location. The DOE tested four factors: Location, Position, Axis, and
Layout. Each sample within a Location was labeled as Positions 1, 2, or 3 depending on the
distance from the center of the platform with Position 1 being the closest to the center. Samples
were fabricated parallel with the x-axis, y-axis, or 45o
 to both axes (called Axis 1, 2, and 3,
respectively) and were fabricated either flat or on an edge relative to the x-y plane (called Layout
1 and 2, respectively). The results from the statistical analyses showed that Axis, Location, and
Position had no significant effect on UTS or E. However, Layout (or whether a sample was built
flat or on an edge) was shown to have a statistically significant effect on UTS and E (at a 95%
level of confidence). This result was not expected since a comparison of the average UTS for
each Layout showed only a 1.2% difference (6966 psi versus 7050 psi for samples built flat and
on an edge, respectively). Because of the small differences in means for UTS, the statistical
differences between Layout most likely would not have been identified without performing the
DOE. Furthermore, Layout was the only factor that tested different orientations of build layers
(or layer-to-layer interfaces) with respect to the sample part, and thus, it appears that the
orientation of the build layer with respect to the fabricated part has a significant effect on the
resulting mechanical properties. This study represents one of many to follow that is using
statistical analyses to identify and classify important fabrication parameters on mechanical
properties for layer manufactured parts. Although stereolithography is the focus of this work, the
techniques developed here can be applied to any layered manufacturing technology.",,,,,,
"['Jorapur, Nikhil', 'West, Robert', 'Williams, Christopher B.', 'Druschitz, Alan']",2021-11-01T21:02:08Z,2021-11-01T21:02:08Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89750,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['tensegrity behavior', 'fiber-reinforced cellular structures', 'cellular structures', 'sand molds', '3D printing']",Design of Fiber-Reinforced Cellular Structures with Tensegrity Behavior Manufactured Using 3D Printed Sand Molds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4744a3fb-ee79-4a9e-b5d6-66a80287712c/download,University of Texas at Austin,"Tensegrity structures provide a high stiffness to mass ratio since all the comprising
elements are either in compression or tension. However, they have limited applications since
fabrication of such structures is challenging due to their complexity and mainly requires manual
assembly of components. The authors look to Additive Manufacturing (AM) as a means to
introduce tensegrity behavior in cellular structures to enhance structural performance. Specifically,
octet cellular structures are created by casting aluminum into 3D-printed sand molds embedded
with continuous wires. In this paper, the authors describe design and analysis of octet cellular
structures that feature high strength fibers held in continuous tension. Finite element analysis of 4-
point bending test is used to evaluate the effectiveness of embedded fibers. Also, the presence of
tensegrity behavior was evaluated using this analysis and testing. The structure with tensegrity
behavior was found to be 30 % stronger. The simulation and experimental results were shown to
match within 6 % error in the elastic region.",,,,,,
"['Modica, F.', 'Stöckli, F.R.', 'Shea, K.']",2021-10-21T19:57:24Z,2021-10-21T19:57:24Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89436,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'walking robots', 'passive dynamic walkers', 'additive manufacturing']",Design of Passive Dynamic Walking Robots for Additive Manufacture,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a5eec83-109b-497e-889a-8f67ef3a252a/download,University of Texas at Austin,"Ongoing research in the direction of printable, non-assembly mechatronic systems give
rise to the need for multi-material printing, including electronics. However, there are robotic
systems that do not use electronic components and still exhibit complex dynamic behavior. Such
passive dynamic systems have the potential to save energy and component cost in the field of
robotics compared to actuated systems. Ongoing research in computational design synthesis of
passive dynamic systems aims at automatically generating robotic configurations based on a
given task. However, an automated design-to-fabrication process also requires a flexible
fabrication method. Towards the goal of printing functional, non-assembly passive dynamic
robots using Fused Deposition Modeling (FDM), this paper explores designing and fabricating
passive walking robots and all necessary components using single material FDM. Two
configurations of passive dynamic walkers are re-designed and fabricated in this paper. For one
of them all components are printed in one job and only little assembly after printing is needed.
However, the gait cycle of the second configuration is much more sensitive to small parametric
changes and therefore more flexible prototyping is needed in order to allow adjusting of the robot
after printing. Moreover, FDM printed robotic joints with sufficient smoothness and axial
stiffness are required and a variety of different joint assemblies are designed and tested for the
robot prototypes. Even though the most stable gait for the second robot is achieved using a metal
bearing instead of the FDM printed ones, this is not necessary for the first robot example. The
approach to prototyping with FDM presented in this paper allows achieving functionality through
design iteration without incurring significant cost. To arrive at feasible solutions, a modular
design approach allows to combine different joints, legs, feet and balancing weights and the
connection points of the different elements are adjustable after printing, which makes it possible
to shift the center of gravity and other variables of the robot.",,,,,,
"['Kumar, Vikas', 'Manogharan, Guhaprasanna', 'Cormier, Denis R.']",2021-09-29T18:14:23Z,2021-09-29T18:14:23Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88206', 'http://dx.doi.org/10.26153/tsw/15147']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['powder based metal', 'additive manufacturing', 'heat exchangers', 'catalyst support structures', 'hexagonal periodic cellular structures', 'cellular structure orientation']",Design of Periodic Cellular Structures for Heat Exchanger Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9542a938-17c1-4d27-b638-a2eaf02c2548/download,University of Texas at Austin,"Powder based metal additive manufacturing processes generally produce parts with a textured
surface. Although surface roughness is undesirable in most cases, it can be advantageous for
applications such as heat exchangers or catalyst support structures. While stochastic metal foams
have been used for these applications, it is not possible to tailor the foam geometry to the
application. SFF techniques permit designers to use different cell geometries and orientations to
achieve specific performance objectives. More specifically, the unit cell type and size, ligament
size, and cell orientation have a considerable influence on surface area, volume, density and fluid
flow behavior of the lattice structure. This paper illustrates the effect of the orientation of
hexagonal periodic cellular structures on heat transfer and pressure drop. Finite element analysis
of air flowing through the hot hexagonal periodic cellular structures shows the effect of
orientation on heat transfer and pressure drop. The analysis indicates that the ideal orientation is
dependent on the specific application.",,,,,,
"['Wei, Chongyi', 'Smith, Douglas E.']",2024-03-27T03:46:26Z,2024-03-27T03:46:26Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124474', 'https://doi.org/10.26153/tsw/51082']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['triply periodic minimal surface', 'lattice structures', 'additive manufacturing']",Design of Spatially Varying Orientation Lattice Structures Using Triply Periodic Minimal Surfaces,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7205fec3-59d5-4a7e-8cc7-ddb7077748fa/download,University of Texas at Austin,"Interest continues to grow for lattice structures produced by additive manufacturing
methods that are described by triply periodic minimal surface (TPMS). Tunable parameters that
define the TPMS provide unique design flexibility where prior research has focused on designing
hybrid or functionally graded TPMS structures. In this paper, a new strategy is proposed to
include an orientation angle and volume fraction of each lattice cell simultaneously when
defining structures derived from TPMS. The algorithm iteratively solves an underlying partial
differential equation with the finite difference method to obtain a smooth, continuous lattice
structure with a spatially varying orientation angle. The resulting lattice structure can be
combined with other types of TPMS models using Gaussian radial basis and distance functions
to achieve multi-TPMS lattice designs. The spatially varying lattice structures can also take the
advantage of the directional effective modulus of TPMS to improve the strength the performance
of lattice design.",,,,,,
"['McDowell, Christopher S.', 'Boomer, Mark C.']",2018-11-14T17:47:00Z,2018-11-14T17:47:00Z,1996,Mechanical Engineering,doi:10.15781/T2V980B5V,http://hdl.handle.net/2152/70249,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'Investment casting', 'SL pattern generation']",Design of Stereolithography Trees for Use in the Investment Casting of Stereolithography Patterns,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbd342ee-c9e4-4ff6-8b21-3809d0f1db30/download,,,,,,,,
"['Gao, Feng', 'Koresawa, Hiroshi', 'Narahara, Hiroyuki', 'Suzuki, Hiroshi']",2019-10-30T16:51:25Z,2019-10-30T16:51:25Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78191', 'http://dx.doi.org/10.26153/tsw/5280']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Thermal Environment,Design of Thermal Environment in Plastic Injection Mold Based on Evaluation of Resin Cooling Uniformity,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f4bccce-4aff-47be-9bd2-0dc88563191d/download,,"Thermal state in plastic injection molds greatly influences the molding quality of products. This paper discusses the optimum design of thermal environment in the molds by observing and estimating the cooling uniformity of resin. Numerical analysis based on unsteady heat transfer is conducted to confirm the utility of the proposed evaluation method, and case studies show the comparison results of resin deformations under different cooling systems conditions and the improved designs.",,,,,,
"['Fitzpatrick, Angus', 'Mohammed, Mazher', 'Collins, Paul', 'Gibson, Ian']",2021-11-08T21:08:04Z,2021-11-08T21:08:04Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90041', 'http://dx.doi.org/10.26153/tsw/16962']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['patient specific', 'design', '3D printing', 'orthosis', 'optimisation']",Design Optimisation of a Thermoplastic Splint,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f470aba-2bcb-4c06-819a-5f06c87061ab/download,University of Texas at Austin,"Following partial hand amputation, a post-surgery orthosis is required to hold the
remaining ligaments and appendages of the patient in a fixed position to aid recovery. This
type of orthosis is traditionally handmade and fabricated using laborious and qualitative
techniques, which would benefit from the enhancements offered by modern 3D technologies.
This study investigated the use of optical laser scanning, Computer Aided Design (CAD) and
Material Extrusion (ME) additive manufacturing to manufacture a polymeric splint for use in
post-surgical hand amputation. To examine the efficacy of our techniques, we take an existing
splint from a patient and use this as the template data for production. We found this approach
to be a highly effective means of rapidly reproducing the major surface contours of the orthosis
while allowing for the introduction of advanced design features for improved aesthetics,
alongside reduced material consumption. Our demonstrated techniques resulted in a more
lightweight and lower cost device, while the design and manufacturing elements afford greater
flexibility for orthosis customisation. Ultimately, this approach provides an optimized and
complete methodology for orthosis production.",,,,,,
"['Chahine, Gilbert', 'Atharifar, Hosein', 'Smith, Pauline', 'Kovacevic, Radovan']",2021-09-29T17:34:51Z,2021-09-29T17:34:51Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88197', 'http://dx.doi.org/10.26153/tsw/15138']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['finite element analysis', 'dental implants', 'design optimization', 'Electron Beam Melting']",Design Optimization of a Customized Dental Implant Manufactured via Electron Beam Melting®,Conference paper,https://repositories.lib.utexas.edu//bitstreams/79a0b434-bfcf-470b-b4fe-12a861a5acec/download,University of Texas at Austin,"Finite Element Analysis (FEA) is a commonly used tool to evaluate biomechanics of traditional dental implants.
Biomechanics help predict bone response and implant retention which strongly affects the longevity of the
implant. The current research utilizes an analogues approach with FEA, to evaluate the biomechanics of a
customized dental implant design built by Electron Beam Melting®, and to contribute towards the implant’s
design optimization. The analysis consists of three distinct simulation models. The first model is established in
order to get an insight of the biomechanics produced by a biting force of 400 N on a second human molar in the
mandible, its corresponding superposed mate and the surrounding biomaterial. In the second model, the lower
jaw molar is replaced by a Ti-6Al-4V customized dental implant with a solid surface at the root. In the third
model, the customized dental implant has a modified outer-layer at the root with adjustable elasticity. By using a
deterministic optimization technique in the FEA, an elasticity of the modified layer can be selected in a manner
to minimize stress shielding from occurring.",,,,,,
"['Panesar, A.', 'Brackett, D.', 'Ashcroft, I.', 'Wildman, R.', 'Hague, R.']",2021-10-18T21:50:09Z,2021-10-18T21:50:09Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89261,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Topology Optimization', '3D printing', 'multifuctional parts', 'design optimization']",Design Optimization Strategy for Multifunctional 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/76e40d5f-cd12-4494-8a17-65e7978b2568/download,University of Texas at Austin,"An optimization based design methodology for the additive manufacture of multifunctional parts (for example, a structure with embedded electronic/electrical systems and
associated conductive paths) is presented. This work introduces a coupled optimization strategy
where Topology Optimization (TO) is combined with an automated placement and routing
approach that enables determination of an efficient internal system configuration. This permits
the effect of the incorporation of the internal system on the structural response of the part to be
taken into account and therefore enables the overall optimization of the structure-system unit. An
example test case is included in the paper to evaluate the optimization strategy and demonstrate
the methods effectiveness. The capability of this method allows the exploitation of the
manufacturing capability under development within the Additive Manufacturing (AM)
community to produce 3D internal systems within complex structures.",,,,,,
"['Gibson, I.', 'Goenka, G.', 'Narasimhan, R.', 'Bhat, N.']",2021-09-30T20:10:54Z,2021-09-30T20:10:54Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88293', 'http://dx.doi.org/10.26153/tsw/15234']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Additive Manufacturing', 'layer-based fabrication', 'AM constraints', 'AM technology', 'design rules']",Design Rules for Additive Manufacture,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6feb6d2d-2efe-4be0-903f-33fb9d04b0a9/download,University of Texas at Austin,"As Rapid Prototyping (RP) has evolved to become Additive Manufacture (AM) it has become
possible to exploit the effects of the layer-based approach to fabrication so that parts can become
easier to build and with greater functionality. Initially parts made in a manner that could not be
manufactured further using conventional processes were considered merely as a novelty to RP
machine users rather than of any wider benefit. With improvements in the technology and
increasing demand for more complex geometry products, AM is coming into its own. As a result,
we are now able to manufacture parts that have interlocking features, overlapping and
mechanistic properties as well as us not having to worry about constraints like draft angles and
overhanging features.
However, this does not mean we can completely ignore manufacturing constraints. More that we
have to concern ourselves with a different set of constraints. AM technologies are limited
according to the following (1): -
Speed of build
Accuracy
Surface geometry
Tolerances
Wall thickness and feature size
Material properties
Range of materials
These have always been an issue; it’s just that now improvements have now gotten to the stage
where parts are acceptable for final application. We must therefore concern ourselves with a new
set of design rules that allow us to understand how the technology can be best applied to the
advantage of the creator of the new products...",,,,,,
"['Kelly, S.', 'Paterson, A.M.J.', 'Bibb, R.J.']",2021-11-09T20:55:12Z,2021-11-09T20:55:12Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90162', 'http://dx.doi.org/10.26153/tsw/17083']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'wrist splints', 'finite element analysis', 'design of experiments']",Design Rules for Additively Manufactured Wrist Splints Created Using Design of Experiment Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9a249b9-e4ff-433f-b2be-b09447d54bde/download,University of Texas at Austin,"Research has shown that wrist splints can be made using Additive
Manufacturing (AM) with a similar or greater performance than splints created using
traditional manufacturing methods. By using AM, many of the problems associated with
traditional splinting such as poor aesthetics and poor ventilation could be mitigated.
However, work to date typically reviews splints with singular pattern designs (e.g. Voronoi
patterns), which have structural and safety implications if similar but untested patterns are
created. Using Design of Experiments (DOE) design rules were to enable clinicians to
confidently design splints alongside their patients.
Design rules were created by investigating variables of cut out patterns using DOE
methods. Finite Element Analysis (FEA) of various combinations of cut out variables was
conducted.",,,,,,
"['Jee, H.', 'Lu, Y.', 'Witherell, P.']",2021-10-21T19:33:40Z,2021-10-21T19:33:40Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89430,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['design rules', 'modularity', 'additive manufacturing']",Design Rules with Modularity for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9884ccbb-0d78-418d-b07f-1e0ad4576d77/download,University of Texas at Austin,"Design rules for additive manufacturing (AM) can help ensure manufacturability, which can be
viewed as compatibility between designs and the fabrication processes that produce those designs.
Additionally, such rules frequently provide direct guidelines or constraints for designing AMdestined parts. Here, we present design rules as sets of modular components and associated
formalisms. Independent of context, these representations can be more easily interpreted and
efficiently implemented. Given context, components are specialized to represent process-specific
parameters for different AM builds and processes. This method of specialization enables designers
to reconfigure design rules, rather than create new rules from scratch, thus preserving fundamental
AM principles while supporting customization and explicit representation.",,,,,,
"['Wang, Hongqing Vincent', 'Williams, Chris', 'David W., Rosen']",2020-03-02T15:16:11Z,2020-03-02T15:16:11Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80130', 'http://dx.doi.org/10.26153/tsw/7151']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Mesoscopic Cellular Structure,Design Synthesis of Adaptive Mesoscopic Cellular Structures with Unit Truss Approach and Particle Swarm Optimization Algorithm,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c269ce7a-a4d2-4246-9d01-14e2c7525b83/download,,"Cellular material structures have been engineered at the mesoscopic scale for high performance
and multifunctional capabilities. However, the design of adaptive cellular structures - structures with
cellular configurations, sizes, and shapes designed for a specific geometric and loading context - has
not been sufficiently investigated. In this paper, the authors present a design synthesis method with the
use of unit truss approach and particle swarm optimization algorithm to design adaptive cellular
structures. A critical review is presented to show the pros and cons of the new design synthesis method
and an existing homogenization method. The research extends the application of additive
manufacturing in the design of new materials for high performances and benefits its long-term growth.",,,,,,
"['Lane, B.', 'Mekhontsev, S.', 'Grantham, S.', 'Vlasea, M.L.', 'Whiting, J.', 'Yeung, H.', 'Fox, J.', 'Zarobila, C.', 'Neira, J.', 'McGlauflin, M.', 'Hanssen, L.', 'Moylan, S.', 'Donmez, A.', 'Rice, J.']",2021-10-28T15:24:16Z,2021-10-28T15:24:16Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89662,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing metrology testbed', 'AMMT', 'National Institute Standards and Technology', 'NIST', 'system design', 'system construction']","Design, Developments, and Results from the NIST Additive Manufacturing Metrology Testbed (AMMT)",Conference paper,https://repositories.lib.utexas.edu//bitstreams/114e208f-21a4-47be-81ac-155b507367f4/download,University of Texas at Austin,"The National Institute of Standards and Technology (NIST) is developing a facility titled
the Additive Manufacturing Metrology Testbed that will enable advanced research into
monitoring, controls, process development, and temperature measurement for laser powder bed
fusion additive manufacturing and similar processes. This system provides an open control
architecture as well as a plethora of sensor systems and calibration sources that are primarily
radiance-based and aligned co-axially with the laser beam and focused on the laser interaction
zone. This paper briefly reviews the system requirements, and details the current progress of the
facility design and construction. Mechanical, optical, and control systems designs are detailed
with select highlights that may be relevant to additive manufacturing researchers and system
developers. Recent experimental results from the prototype laser control and in-situ monitoring
system are also highlighted.",,,,,,
"['Kashdan, Lia', 'Seepersad, Carolyn', 'Haberman, Michael', 'Wilson, Preston S.']",2021-09-29T20:36:36Z,2021-09-29T20:36:36Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88218', 'http://dx.doi.org/10.26153/tsw/15159']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['constrained bistable structures', 'negative stiffness behavior', 'metamaterials', 'broadband imaging transducers', 'conventional manufacturing', 'selective laser sintering']","Design, Fabrication and Evaluation of Negative Stiffness Elements",Conference paper,https://repositories.lib.utexas.edu//bitstreams/15a9fec0-ba01-4eda-abb5-9068ff4b7fe8/download,University of Texas at Austin,"Recent research has shown that constrained bistable structures can display negative
stiffness behavior and provide extremal vibrational and acoustical absorptive capacity.
These bistable structures are therefore compelling candidates for constructing new
metamaterials for noise reduction, anechoic coatings, and backing materials for
broadband imaging transducers. To date, demonstrations of these capabilities have been
primarily theoretical, because the geometry of bistable elements is difficult to construct
and refine with conventional manufacturing methods and materials. The objective of this
research is to exploit the geometric design freedoms provided by selective laser sintering
(SLS) technology to design and construct constrained bistable structures with negative
stiffness behavior. The static and dynamic behaviors of resulting bistable structures are
experimentally investigated. Initial bistable designs and test results are presented in this
paper.",,,,,,
"['Alayavalli, Kaushik', 'Bourell, David L.']",2021-09-29T17:56:53Z,2021-09-29T17:56:53Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88202', 'http://dx.doi.org/10.26153/tsw/15143']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Direct Methanol Fuel Cells', 'clean energy', 'bipolar plate', 'graphite', 'indirect Selective Laser Sintering']","Design, Fabrication and Testing of Graphite Bipolar Plates for Direct Methanol Fuel Cells",Conference paper,https://repositories.lib.utexas.edu//bitstreams/a60b5d90-8bf7-4b09-97ca-41a34294034c/download,University of Texas at Austin,"Direct Methanol Fuel Cells (DMFCs) are clean energy devices that convert chemical energy into
electrical energy. The bipolar plate component of the DMFC is required to be fluid impermeable
to prevent fuel leakage and electrically conductive to collect the electrons produced within the
cell. Graphite possesses the properties of high electrical conductivity, low weight and resistance
to corrosion that make it an attractive material for bipolar plates. However, the poor mechanical
properties of graphite lead to prohibitive machining costs. The indirect Selective Laser Sintering
(SLS) process, involving the laser sintering of graphite powders mixed with a phenolic resin
binder, offers the advantage of complex part production and testing of prototype bipolar plates in
short times. The current research deals with the production of bipolar plates for DMFC's by
utilizing indirect SLS followed by post processing steps.",,,,,,
"['Geating, J.T.', 'Wiese, M.C.', 'Osborn, M.F.']",2021-11-08T21:18:09Z,2021-11-08T21:18:09Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90044', 'http://dx.doi.org/10.26153/tsw/16965']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'additive manufacturing', 'metal parts', 'quadruped robot', 'quadruped body', 'hydraulic manifold', 'mechanical interface', 'core structure', 'design', 'fabrication', 'qualification']","Design, Fabrication, and Qualification of a 3D Printed Metal Quadruped Body: Combination Hydraulic Manifold, Structure and Mechanical Interface",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c709eaf8-d9c2-4ee8-ae86-0c5d5e65d2d5/download,University of Texas at Austin,"Additive manufacturing allows designers to make complex, efficient parts that are not
achievable through conventional manufacturing techniques. Efficiencies are achieved by
combining structural members, component interfaces, and hydraulic power distribution elements
while eliminating redundant structural mass and volume. This paper documents the design,
fabrication, inspection and testing of complex additively manufactured metal components. Parts
utilizing AlSi10Mg aluminum alloy combine the roles of hydraulic manifold, mechanical
interface, and core structure for a meso-scale quadruped robot. These parts allow Naval Research
Laboratory (NRL) engineers to design and construct a highly capable quadruped robot that is
both dynamic and lightweight. Metal parts were designed with computer aided design (CAD)
and constructed using powder-bed direct laser metal sintering (DLMS). High-pressure hydraulic
lines with internal fluid passageways were printed into the body assembly seamlessly creating a
complex hydraulic manifold. After fabrication, a rigorous program involving post-processing,
inspection, and destructive and non-destructive testing was performed to validate the design and
manufacturing methods. The manifold has been approved for use and integrated on the
quadruped, awaiting system level testing.",,,,,,
"['Peng, Hao', 'Gao, Feng', 'Hu, Wenjing']",2021-11-30T22:05:54Z,2021-11-30T22:05:54Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90564', 'http://dx.doi.org/10.26153/tsw/17483']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['triply periodic minimal surface', 'additive manufacturing', 'heat exchanger', 'lattice structure']","Design, Modeling and Characterization on Triply Periodic Minimal Surface Heat Exchangers with Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/cee91e29-4578-4d2a-b49d-893c5bb562e3/download,University of Texas at Austin,"Next-generation power plants will generate heated fluids at significantly higher
temperatures than current-generation power plants, which challenges the state-of-the-art heat
exchanger design. In this study triply periodic minimal surfaces were combined with additive
manufacturing for next-generation heat exchanger design. Triply periodic minimal surfaces
separate three-dimensional space into two interpenetrating channels, creating high surface area to
volume ratios and low hydrodynamic resistance. Parametric design of triply periodic minimal
surface heat exchanger is straightforward because they are governed by simple implicit functions
with parameters such as periodic length and offset parameter. In this study a design workflow was
developed to streamline the design of triply periodic minimal surface heat exchangers and a
numerical model was developed to optimize triply periodic minimal surface heat exchanger design
for optimal performance. Finally, the optimized triply periodic minimal surface heat exchanger
was printed with EOS M290 DMLS machine and the performance was tested by experiment.",,,,,,
"['Magadum, Sunil', 'Gilorkar, Amol', 'Deepak, M.', 'Rakshith, B.S.', 'Navaharsha, P.', 'Nagahanumaiah', 'Somashekara, M.A.']",2021-11-30T22:18:30Z,2021-11-30T22:18:30Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90568', 'http://dx.doi.org/10.26153/tsw/17487']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'mechanical metamaterials', 'chiral', 're-entrant', 'hybrid model']","Design, Simulation and Experimental Investigation of 3D Printed Mechanical Metamaterials",Conference paper,https://repositories.lib.utexas.edu//bitstreams/0bdcd8f3-265f-430a-a249-e511113716ae/download,University of Texas at Austin,"Mechanical metamaterials have generated special interest recently due to their tailorable
structure, exceptional mechanical properties, and advancements in 3D printing processes that allow
the fabrication of intricately structured components. Designing innovative structures of metamaterials
will lead to the development of advanced materials with special properties. The experimental
investigation presented in this paper involves the design, simulation, fabrication, and testing of three
different mechanical metamaterial models i.e. Chiral, Re-entrant, and Hybrid printed in acrylonitrile
styrene acrylate (ASA) using fused deposition modeling (FDM). Subsequently, a uniaxial
compression test and ex-situ characterization was performed for studying the mechanical properties,
the types of fracture and crack propagation of the printed metamaterial models which may lead to the
development of metamaterials with tunable compressive/bending stiffness.",,,,,,
"['McMillen, Devin', 'Li, Wenbin', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Watts, Jeremy']",2021-10-28T14:11:09Z,2021-10-28T14:11:09Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89644,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['ceramic on-demand extrusion', 'zirconium diboride', 'ceramic powders', 'pre-ceramic organics']",Designed Extrudate for Additive Manufacturing of Zirconium Diboride by Ceramic On-Demand Extrusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5202f12e-1517-4cbe-a12d-af69da16abe4/download,University of Texas at Austin,"This work describes a process by which zirconium diboride (ZrB2) parts may be fabricated
using the Ceramic On-Demand Extrusion (CODE) process. An oxide-carbide-nitride system
consisting of ceramic powders and pre-ceramic organics, designed to yield ZrB2 after reaction
sintering, has been developed to produce an aqueous-based extrudate for subsequent processing in
the CODE system. Pressurelessly sintered test specimens containing 1 wt% PVA binder achieve
high relative density ≥ 99%. The viscoelastic response of the extrudate was characterized via
spindle rheometry with a small sample adapter. Batches with 1 wt% PVA and 0.5 wt% Methocel
show strong shear thinning characteristic, under shear rates of 1-28 s-1. XRD and SEM were
utilized for microstructural analysis to determine phase development and microstructural
morphology.",,,,,,
"['Seepersad, Carolyn Connor', 'Govett, Tyler', 'Kim, Kevin', 'Lundin, Michael', 'Pinero, Daniel']",2021-10-06T22:39:55Z,2021-10-06T22:39:55Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88463', 'http://dx.doi.org/10.26153/tsw/15400']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'selective laser sintering', 'tolerancing', 'dimensioning', 'design for additive manufacturing']",A Designer's Guide for Dimensioning and Tolerancing SLS Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5164ba51-213c-4976-a217-40d025680b0c/download,University of Texas at Austin,"Because additive manufacturing (AM) is a relatively novel industry, with the first
commercial machines introduced in the late 1980s, many designers are unaware of the
capabilities of AM technologies. Many engineers also find it difficult to utilize AM because of a
lack of “Design for AM” knowledge in the public domain. Reliable information on material
properties, dimensions and tolerances, and other process-related specifications is often scattered
throughout the literature, if it is publicly available at all. The objective of the research reported
in this paper is to begin to create a designer's guide for dimensioning and tolerancing parts that
are additively manufacturing using selective laser sintering (SLS) technology. The guide is
based on a series of experiments designed to determine the limiting feature sizes for various
types of features fabricated in commercially available SLS machines. The features include slits,
holes, letters, mating gears, and shafts built in a preassembled state. The impact of part
thickness, orientation, clearance, and dimensions on the resolvability of features is examined.
Results are reported in a series of matrices that relate realizable feature sizes to other important
variables such as part thickness.",,,,,,
"['Leutenecker-Twelsiek, B.', 'Klahn, C.', 'Meboldt, M.']",2021-10-28T22:48:28Z,2021-10-28T22:48:28Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89723,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['Concept Tool', 'additive manufacturing', 'product development']",Designing a Power Tool to Show the Potentials of Additive Manufacturing - Effects of Additive Manufacturing on the Product Development Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b98bae6-eacd-4a15-8e26-9ba036e07cf2/download,University of Texas at Austin,"Today Additive Manufacturing (AM) is mainly used for rapid prototyping and
specialized parts for industrial and end-user applications. To communicate the design potentials of
AM to a general audience it is useful to demonstrate it with a visionary product, similar to the
concept cars of the automotive industry. We have redesigned a power tool to show the benefits of
AM on an end-user product. This paper describes the Concept Tool, its different sub-systems and
highlights the range of AM’s applications. Furthermore we present our observations and findings
during the product development process. Based on these findings a design supporting system is
suggested to improve the development process for additive manufactured products.",,,,,,
"['kumar, Ashok V.', 'Lee, Jongho']",2019-09-23T16:54:11Z,2019-09-23T16:54:11Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75969', 'http://dx.doi.org/10.26153/tsw/3068']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Designing and Slicing Heterogeneous Components for Rapid Prototyping 428,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56fc56bb-5412-4351-9001-3e643706f8a5/download,,Many rapid prototyping techniques have the potential for fabricating components whose composition is non-uniform and varies in a desired fashion. A shape and composition modeling technique was developed to enable the representation and design of such heterogeneous components. Techniques for interactively and automatically designing such components are presented. Automatic design is made possible using optimization techniques where the optimal composition distribution is computed based on specified design objective and constraints. Software was also developed to slice 3D heterogeneous solids to generate cross-sectional images as well as composition distribution for each cross-section. Slicing and generation of cross-sectional data are essential to enable rapid prototyping of these components.,Partial funding from ONR contract N00014-98-1-0694 and NSF contract DMI-9875445 is gratefully acknowledged.,,,,,
"['Xu, Xiaorong', 'Sachs, Emanuel', 'Allen, Samuel', 'Cima, Michael']",2019-02-19T19:39:30Z,2019-02-19T19:39:30Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73436', 'http://dx.doi.org/10.26153/tsw/588']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['3D Printed tools', 'heat transfer']",Designing Conformal Cooling Channels for Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d00c1807-0c98-41c5-8ffb-7531bd6df5e6/download,,"SFF technologies have demonstrated the potential to produce tooling with cooling
channels which are conformal to the molding cavity. 3D Printed tools with conformal cooling
channels have demonstrated simultaneous improvements in production rate and part quality as
compared with conventional production tools. Conformal Cooling lines of high performance
and high complexity can be created, thus presenting a challenge to the tooling designer. This
paper presents a systematic, modular, approach to the design of conformal cooling channels.
Recognizing that the cooling is local to the surface of the tool, the tool is divided up into
geometric regions and a channel system is designed for each region. Each channel system is
itself modeled as composed of cooling elements, typically the region spanned by two channels.
Six criteria are applied including; a transient heat transfer condition which dictates a maximum
distance from mold surface to cooling channel, considerations of pressure and temperature drop
along the flow channel and considerations of strength of the mold. These criteria are treated as
constraints and successful designs are sought which define windows bounded by these
constraints. The methodology is demonstrated in application to a complex core and cavity for
injection molding.",,,,,,
"['Sato, Shoichi', 'Togo, Naoyuki', 'Yamanaka, Shunji']",2021-10-28T22:03:26Z,2021-10-28T22:03:26Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89712,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['functional beauty', 'mass-customized products', 'running-specific prostheses', 'additive manufacturing']",Designing Functional Beauty Through Additive Manufacturing: Prototyping of Running-Specific Prostheses Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b47ed3ae-1416-41a2-b670-b36ae4db4573/download,University of Texas at Austin,"The objective of this research is to establish a new methodology of designing
aesthetically and functionally satisfying mass-customized products that fit individual bodies. The
primal phase of this study, the prototyping of additive manufactured Running-Specific Prostheses
(RSPs), is shown in this paper. The focus of this work is to present the capability of
manufacturing such products by using Additive Manufacturing (AM), especially Laser
Sintering (LS). The first section describes the method in which a design process that uses AM
technologies is established, aiming mainly to achieve a functional product that is also
aesthetically pleasing. The latter section presents engineering verifications of previously designed
prostheses, and the application of structural improvements to achieve enough reliability for user
tests. The improved prosthesis was tested by a transtibial amputee runner; user review and
remaining issues are reported.",,,,,,
"['Spierings, A.B.', 'Wegener, K.', 'Levy, G.']",2021-10-06T19:58:09Z,2021-10-06T19:58:09Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88427', 'http://dx.doi.org/10.26153/tsw/15364']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Selective Laser Melting', 'stainless steel', 'material properties']",Designing Material Properties Locally with Additive Manufacturing Technology SLM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19c07a83-d9f5-4225-b6bc-4058df2482ce/download,University of Texas at Austin,"Additive Manufacturing technologies are known to allow the production of parts with an extreme
degree of complexity, enabling design and functional part optimization. So far the development of
processing parameters and analyze of corresponding materials focuses on dense materials for
maximized material properties. However, AM processes like Selective Laser Melting, allow also the
generation of materials with some degree of porosity affecting their mechanical properties. A DOE was
set up for SLM processed SS 17-4PH / AISI-630 material with porosity between 0% and about 26% in
order to analyze mechanical properties. The results presented show that the porosity significantly
affects material ductility and hardness, offering the possibility to design a material according to the
required mechanical behavior of the parts produced. Therefore, this AM enabling features allows a
multi-property component design by appropriate local parameter setting.",,,,,,
"['Koers, T.', 'Magyar, B.']",2024-03-25T22:06:38Z,2024-03-25T22:06:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124312', 'https://doi.org/10.26153/tsw/50920']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'fused deposition modeling', 'shrinkage', 'additive manufacturing', '2023 Solid Freeform Fabrication Symposium']",DETERMINATION AND COMPENSATION OF THE SHRINKAGE BEHAVIOR OF CYLINDRICAL ELEMENTS IN THE FDM PROCESS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/64cdbe9e-62a5-4a6d-a9f5-98ba768d23e8/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) is an additive manufacturing process to produce
complex thermoplastic geometries layer by layer. The filament is melted in a nozzle, iteratively
deposited, and then cools down. Due to the solidification process, the deposited filament strands
deviate from their intended position due to shrinkage, resulting in significant geometric deviations
in the final part. In terms of dimensional accuracy, there is a need for optimization, especially for
local curved geometries in relation to the global part with higher nominal dimensions. The aim of
this study is to investigate the size and shape deviations for cylindrical FDM elements and to
compensate the expected deformations by using an in-house software with adaptive scaling factors
in the x-y plane. Previous studies mainly focus on simple, non-curved objects, this study also
considers the influence of curvature and global as well as local deviations on the final part.",,,,,,
"['Zhang, Wei', 'Sui, Guanghua', 'Leu, Ming C.']",2019-09-23T17:15:08Z,2019-09-23T17:15:08Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75979', 'http://dx.doi.org/10.26153/tsw/3078']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Determination and Improvement of Building Speed in Rapid Freeze Prototyping 514,Conference paper,https://repositories.lib.utexas.edu//bitstreams/545bff11-7c01-446d-a7b8-81f42119b2d1/download,,"Rapid freeze prototyping (RFP) is a solid freeform fabrication process that builds an ice part by rapidly freezing water in a layer by layer manner. One advantage of this process is the ability to build ice parts faster than other SFF processes. The factors that affect the speed of contour building and interior filling in RFP are identified. The influence of these factors is
analyzed through heat transfer and material flow analyses. A model based on heat transfer analysis is proposed to determine the maximum achievable speed of contour building under stable conditions. Experiments are conducted to validate the performance of the proposed model for determination of building speed.",,,,,,
"['Le, Thao', 'Bhate, Dhruv', 'Parsey, John M.', 'Hsu, Keng H.']",2021-11-04T19:34:16Z,2021-11-04T19:34:16Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90011', 'http://dx.doi.org/10.26153/16932']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['honeycomb structures', 'material modulus', 'shape', 'size', 'additive manufacturing']",Determination of a Shape and Size Independent Material Modulus for Honeycomb Structures in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e8e76c3c-0155-4ad9-a9f6-642842ce68da/download,University of Texas at Austin,"Most prior work on modeling cellular structures either assumes a continuum model or
homogenizes “effective” cell behavior. The challenge with the former is that bulk properties do
not always represent behavior at the scale of the cellular member, while homogenization results in
models that are shape specific and offer little insight into practical design matters like transitions
between shapes, partial cells or skin junction effects. This paper demonstrates the strong
dependence of measured properties on the size of the honeycomb specimen used for experimental
purposes and develops a methodology to extract a material modulus in the presence of this
dependence for three different honeycomb shapes. The results in this paper show that the extracted
modulus for each shape converges as the number of cells in the specimen increases and further,
that the converging values of the material moduli derived from the three shapes are within 10% of
each other.",,,,,,
"['Sparks, Todd', 'Pan, Heng', 'Liou, Frank']",2020-02-21T16:10:46Z,2020-02-21T16:10:46Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80067', 'http://dx.doi.org/10.26153/tsw/7089']",eng,2005 International Solid Freeform Fabrication Symposium,Open,powder delivery system,Determination of Dynamic Powder Modeling Parameters via Optical Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b0e85c8-fde6-42f3-b916-115b58c876d0/download,,,,,,,,
"['Yamauchi, Yuki', 'Kigure, Takashi', 'Niino, Toshiki']",2024-03-25T22:08:30Z,2024-03-25T22:08:30Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124313', 'https://doi.org/10.26153/tsw/50921']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PBF-LB/P', 'laser', 'infrared', 'additive manufacturing']",DETERMINATION OF INPUT LASER ENERGY FOR MELTING POWDER LAYERS OF VARIOUS THICKNESSES IN HIGH-SPEED PBF-LB/P USING NEARINFRARED LASER AND ABSORBENT,Conference paper,https://repositories.lib.utexas.edu//bitstreams/96589552-a18d-4250-8ac5-558e6d1c5fb0/download,University of Texas at Austin,"The rate of production of PBF-LB/P can be increased by increasing the layer thickness.
However, this reduces the part resolution in the stacking direction. To obtain both a high rate
of production and high part resolution, layer thickness adjustment in accordance with part
geometry can be effective. Optimizing the input laser energy with respect to the layer thickness
ensures sufficient melting and part strength. According to previous studies, the use of a nearinfrared laser and absorbent can increase penetration depth or depth of fusion. However, the
optical properties of the powder bed can vary significantly depending on the layer thickness,
and, therefore, the input energy that actually contributes to melting also changes with layer
thickness. This study proposes a method for determining the input laser energy for various layer
thickness without trial and error by estimating the amount of energy required to melt the powder
layer while accounting for the optical properties of the bed.",,,,,,
"['Obielodan, J.O.', 'Stucker, B.E.']",2021-09-30T15:14:05Z,2021-09-30T15:14:05Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88261', 'http://dx.doi.org/10.26153/tsw/15202']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['dissimilar material systems', 'material systems joints', 'laser metal deposition', 'dual-material structures', 'Ti6Al4V', 'Ti6Al4V/10%TiC', 'laser engineering net shaping', 'tensile strength']",Determination of the Optimum Joint Design for LENS Fabricated Ti6Al4V and Ti6Al4V/TiC Dual-Material Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1bea6030-e104-4651-a093-d35e655aa68c/download,University of Texas at Austin,"Joints between dissimilar material systems made using laser metal deposition processes
have been investigated. The fusion of materials with different physical properties and chemical
compositions under high laser power often results in defects at the joints. Although some
solutions have been suggested in previous work for defect-free fabrications, most of the joints
studied have been characterized using qualitative techniques only. Quantitative study is
imperative for predicting the mechanical behavior of fabricated structures for real life
applications. In this work, tensile and flexural specimens made of different Ti6Al4V and
Ti6Al4V/10%TiC dual-material transition joint designs were fabricated using laser engineered
net shaping (LENS) and tested. It was found that transition joint design has a significant effect
on the tensile strengths of dual-material structures.",,,,,,
"['Vijayan, Ajay Panackal Padathu', 'Sparks, Todd', 'Ruan, Jianzhong', 'Liou, Frank']",2020-03-05T19:26:14Z,2020-03-05T19:26:14Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80145', 'http://dx.doi.org/10.26153/tsw/7166']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Aided Manufacturing Process,Determination of Transformation Matrix in a Hybrid Multi-Axis Laser-Aided Manufacturing System and its Practical Implementation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7927e540-cae4-4da6-9e13-67d36092a717/download,,,,,,,,
"['Morris, C.', 'Cormack, J.M.', 'Hamilton, M.F.', 'Haberman, M.R.', 'Seepersad, C.C.']",2021-11-02T17:57:10Z,2021-11-02T17:57:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89839,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['microstereolithography', ""complex young's modulus"", 'material parameters']",Determining the Complex Young’s Modulus of Polymer Materials Fabricated with Microstereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ace06d7-6760-4580-8b04-275c375efd10/download,University of Texas at Austin,"Microstereolithography is capable of producing millimeter-scale polymer parts having
micron-scale features. Material properties of the cured polymers can vary depending on build
parameters such as exposure time and laser power. Current techniques for determining the
material properties of these polymers are limited to static measurements via
micro/nanoindentation, leaving the dynamic response undetermined. Frequency-dependent
material parameters, such as the complex Young’s modulus, have been determined for other
relaxing materials by measuring the wave speed and attenuation of an ultrasonic pulse traveling
through the materials. This method is now applied to determine the frequency-dependent
material parameters of polymers manufactured using microstereolithography. Because the
ultrasonic wavelength is comparable to the part size, a model that accounts for both geometric
and viscoelastic effects is used to determine the material properties using experimental data.",,,,,,
"['Kumar, Jeevan', 'Huseynov, Orkhan', 'Fidan, Ismail', 'Rajabali, Ismail']",2024-03-25T22:33:18Z,2024-03-25T22:33:18Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124324', 'https://doi.org/10.26153/tsw/50932']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PLA', 'LCMMEX', 'iron', 'additive manufacturing']",Developing Additively Manufactured Iron Powder-filled PLA Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d22d998-fea6-459b-978b-7f8d55317a68/download,University of Texas at Austin,"The Low-Cost Metal Material Extrusion (LCMMEX) process has gained attention in
recent years to produce metallic parts with complex designs. High Iron concentration
composite materials have been extensively researched to improve their properties and
functionality for advanced manufacturing applications. This study aims to develop knowledge
blocks for producing composite parts with high iron percentages and analyze their physical
properties based on print parameters. A rectangular sample is manufactured using the Material
Extrusion (MEX) process, with variations in layer height, infill density, and print speed. The
investigation shows that a number of parameters affects the change in surface roughness,
weight, and dimensional accuracy of the printed parts. Furthermore, an increase in the infill
percentage leads to a significant increase in magnetic flux. This research study provides
insights into the influence of print parameters on the properties of high-iron-filled composite
parts, ideal for high-density applications.",,,,,,
"['Knapp, Mary E.', 'Wolff, Ryan', 'Lipson, Hod']",2021-09-23T22:50:51Z,2021-09-23T22:50:51Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88047', 'http://dx.doi.org/10.26153/tsw/14988']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['printable content', 'open wiki-style website', 'educational archive']",Developing printable content: A repository for printable teaching models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee82351f-cbe3-433c-bf1c-50a25dc576e5/download,,"Alongside the development of RP technology, there is an increasing need to develop and
share printable content. Like digital photography and digital music, content drives
technology as much as technology drives content. This paper describes the development
and population of an open wiki-style website (3Dprintables.org) that houses an archive of
printable models for education. Teaching models were chosen as the initial focus for this
effort for two key reasons. First, quality educational models are difficult for teachers to
obtain due to high prices, limited availability, and limited customization options; and
second, many studies have demonstrated that learning is enhanced when students interact
with physical models. Such models are also indispensible tools for teaching the visually
impaired and those with spatial reasoning difficulties. At present, the website contains
models relevant to mechanical engineering, aerospace, biochemistry, mathematics,
anatomy, and archaeology (e.g. proteins, airfoils, kinematics models, cuneiform tablets).
These models are intended to serve as ""seeds"" to encourage educators to further develop
and share printable models and the associated curricular materials.",,,,,,
"['Takagi, Tarou', 'Yashiki, Tatsuro', 'Nagumo, Yasushi', 'Numata, Shouhei', 'Sadaoka, Noriyuki']",2019-10-24T18:09:07Z,2019-10-24T18:09:07Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77414', 'http://dx.doi.org/10.26153/tsw/4503']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Hydraulic Pump,Development of 3D Bit-Map-Based CAD and Its Application to Hydraulic Pump Model Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e705fad-3c04-4ae0-8836-bda0028f6c89/download,,"A novel 3D bit-map-based CAD has been developed. This program, named CellCAD,
relies on techniques which provides easy manipulation of huge sized 3D bit-map, poly-triangle
and 2D bit-map data. It can be attached to various kinds of additional plug-in processors to
extend its functions and to customize it highly for broad applications. CellCAD can be applied
in fields using computed tomography digitizers and/or layering fabricators. The authors applied
CellCAD to hydraulic pump model fabrication. This paper reports the basic design concept and
implementation techniques of CellCAD from the viewpoint of design engineering, and also
introduces the methods and results of an actual CellCAD application.",,,,,,
"['Dwivedi, Indira', 'Dwivedi, Rajeev', 'Dwivedi, Bharat', 'Rebbapragada, Arun', 'Rebbapragada, Arka']",2024-03-27T16:10:22Z,2024-03-27T16:10:22Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124503', 'https://doi.org/10.26153/tsw/51111']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'robotics', 'education', 'competition', 'additive manufacturing']",Development of 3D Printable Part Library for Easy to Manufacture Components for Educational and Competitive Robotics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2180edc1-5bc0-4adb-b539-b500cb14fddd/download,University of Texas at Austin,"Educational and competitive robotics enable hands on learning and experimentation. Despite cost
effective and ease of access of open source micro-controllers, drives and sensors, the structural
components and brackets continue to be very expensive. Motivated by the Robotics for Everyone
initiative, we are developing many easy-to-manufacture parts that will allow learners to easily 3D
print parts for (1) Structural assembly of robot chassis (2) Sensor mounting (3) Electronic control
mounting (4) Power supply (5) Various power drives. The ecosystem of the robotic components is
developed around extrusion structures and tubular elements and 3D printing is used for building the
parts for testing and qualifying. Fixtures for mounting cameras for advanced machine learning and
computer vision experiments are provided.",,,,,,
"['Yang, Li', 'Zhang, Shanshan', 'Oliveira, Gustavo', 'Stucker, Brent']",2021-10-07T18:45:04Z,2021-10-07T18:45:04Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88502', 'http://dx.doi.org/10.26153/tsw/15436']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['dental restorations', 'additive manufacturing', 'porcelain powder', 'sintering', '3D printing']",Development of a 3D Printing Method for Production of Dental Application,Conference paper,https://repositories.lib.utexas.edu//bitstreams/773b4c3f-1c92-4d04-ae42-82513c1428da/download,University of Texas at Austin,"Traditionally, the manufacturing of dental restorations, including crowns, veneers and
other structures made by ceramics, is a labor‐intensive and time consuming process.
Additive manufacturing has the potential to significantly decrease the time and cost
associated with this process. This work performed preliminary investigation for the
feasibility of dental restoration parts printing using the ExOne M‐Lab system with a
commercialized dental porcelain powder. The porcelain powders were characterized,
and two measurements, including pre‐sintering and addition of flow agent, were taken
in the attempt to improve the processability of the original powder feedstock. The
results showed that while the addition of flow agent has more significant effects in
improving the flowability of the powder used, the post sintered parts exhibit
considerable shrinkage and residual porosity that necessitates further investigation.",,,,,,
"['McNulty, Thomas F.', 'Cornejo, Ivan', 'Mohammadi, Farhad', 'Danforth, Stephen C.', 'Safari, Ahmad']",2019-02-26T21:00:54Z,2019-02-26T21:00:54Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73503', 'http://dx.doi.org/10.26153/tsw/653']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['FDC', 'PZT']",Development of a Binder Formulation for Fused Deposition of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e548cca4-df05-4856-b3b0-6de8b4ce21f9/download,,"A new binder formulation has been developed for Fused Deposition of Ceramics
(FDC) which consists of commercially-available polymer constituents.. This formulation
was used. in conjunction with lead zirconate titanate (PZT) and hydroxyapatite (HAp)
powders. Adsorption studies were performed to test the effectiveness of several
carboxylic acids and alcohols on the dispersion ofthese powders in the binder system. In
both cases, it was found that stearic acid was most effective as a dispersant for the
ceramic powder / thermoplastic system. After a suitable dispersant was chosen, ceramic
powders were compounded with the binder formulation to yield 55 vol.% ceramic-loaded
materials. The resultant compound was·used to make filament suitable for use in a
modified StratasysTM 3D-Modeler. The filament was well suited for FDC usage, and the
parts made using FDC contained no detectable filament-related defects",,,,,,
"['Wang, Jia-Chang', 'Hitesh, D.']",2021-11-18T19:09:02Z,2021-11-18T19:09:02Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90472', 'http://dx.doi.org/10.26153/tsw/17393']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D printing', 'ceramics', 'slurry', '3S ceramics', 'alumina']",Development of a Circular 3S 3D Printing System to Efficiently Fabricate Alumina Ceramic Products,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1baf0dc7-01ad-4d57-b0b1-fa2f6599bcde/download,University of Texas at Austin,"The Solvent based Slurry Stereolithography (3S) system has the capability of fabricating high
quality objects using high performance ceramic (HPC) material. The 3S system is able to fabricate
intrinsic features without supporting structures; while its downsides exhibit consuming lot of time
(30 sec/layer) for fabrication compared to other DLP apparatuses and low efficiency raw material
consumption. A new system named as Circular - 3S (C3S) is developed by adapting the 3S
technology to improve the fabrication process. It consists of multiple DLP and a circular platform
where a paving blade paves the slurry in a circular manner. The demonstrated system has increased
the production rate to 200% with printing speed of 15sec/layer. In this paper, the development of
the C3S system is presented by simultaneously displaying the capabilities and raw material
efficiency of the new C3S system.",,,,,,
"['Kumar, Saripella Surya', 'Stucker, Brent']",2020-02-21T15:48:39Z,2020-02-21T15:48:39Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80064', 'http://dx.doi.org/10.26153/tsw/7086']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Intermetallic,Development of a Co-Cr-Mo to Tantalum Transition using LENS for Orthopedic Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9594083-498c-4bc0-8868-af20584c8f93/download,,"Biomedical implant material research using additive manufacturing is a popular field of
study. Many potential material combinations exist which, if implemented properly, could
have a significantly positive effect on implant life and functionality. One material
combination of interest is attaching porous Ta bone ingrowth material to a CoCrMo
corrosion and wear resistant bearing surface. An investigation of the ability of the LENS
process to join Ta to CoCrMo was undertaken. Direct joining of CoCrMo to Ta was
known to be problematic, and thus transitional layers of other biomedically-compatible
materials were investigated. It was determined that a transitional layer of zirconium
appeared to be the best transitional material for this application due to its excellent
biocompatibility, followed by stainless steel, with a lesser biocompatibility but better
adhesive properties.",,,,,,
"['Ma, Zhichao', 'Munguia, Javier', 'Hyde, Philip', 'Drinnan, Michael']",2021-11-09T18:48:07Z,2021-11-09T18:48:07Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90115', 'http://dx.doi.org/10.26153/tsw/17036']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['reverse engineering', 'additive manufacturing', 'CPAP mask', 'continuous positive airway pressure', 'obstructive sleep apnoea', 'customization']",Development of a Customized CPAP Mask Using Reverse Engineering and Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9636681-4afe-4002-a644-f4f7457d6544/download,University of Texas at Austin,"Continuous positive airway pressure (CPAP) therapy has been widely used to treat moderate
and/or severe Obstructive Sleep Apnoea (OSA) syndrome since its invention. However, CPAP
mask interface induced side effects, such as air leak, noise, discomfort and facial skin problem,
considerably affect the overall effectiveness of CPAP treatment. Conventional CPAP masks
designed with averaged individual facial characteristics have standard configuration and
limited material selection. Mask size ranges are limited, only coming with small, medium, and
large. The material used for the mask interface fabrication is mainly silicone-based material.
Besides the limitations on mask configuration and material, there are no comprehensive mask
selection templates and guidance offered by CPAP mask suppliers. Individuals have
completely different physical characteristics, such as face topology, skin sensitivity, the
severity of OSA syndrome, sleep habit and breathing pattern. Therefore, conventional masks
cannot properly fit individual’s physical characteristics. Customization of CPAP mask using
Reverse Engineering and Additive Manufacturing techniques offers the great potential to
minimize the CPAP mask interface induced side effects.",,,,,,
"['Boivie, K.', 'Sørby, K.', 'Brøtan, V.', 'Ystgaard, P.']",2021-10-04T21:03:35Z,2021-10-04T21:03:35Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88345', 'http://dx.doi.org/10.26153/tsw/15284']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'injection molding', 'tool production', 'insert production', 'CNC milling', 'hybrid process']",Development of a Hybrid Manufacturing Cell; Integration of Additive Manufacturing with CNC Machining,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ac15a0b-0f02-4c1e-b51a-419d1ae4e37b/download,University of Texas at Austin,"The application of Additive Manufacturing (AM) for production of injection molding
tools and tooling inserts enables significant improvements in regards to, for example, product
quality and cycle times. However, the AM based production of tools and inserts is most often
far from being rapid and the inserts are usually considerably more expensive than
conventionally produced. A combination of AM with CNC milling in a hybrid process route
allows for the application of each process to the production of the section of the product
geometry for which it is most advantageous. However, this approach also multiplies the
number of process steps and therefore also the limiting factors and possible causes of failure.
This paper describes the development of a Hybrid Manufacturing cell by integration of AM
with conventional CNC milling in a robust, streamlined production sequence.",,,,,,
"['Hill, Leon', 'Sparks, Todd', 'Liou, Frank']",2021-11-04T18:20:02Z,2021-11-04T18:20:02Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89996', 'http://dx.doi.org/10.26153/16917']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['metal parts', 'CNC-level precision', 'hybrid manufacturing', 'research & development', 'R&D']",Development of a Hybrid Manufacturing Process for Precision Metal Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/230c1726-7ab1-4ce2-b57c-5ded25f5131e/download,University of Texas at Austin,"This paper summarizes the research and development of a hybrid manufacturing process to
produce fully dense metal parts with CNC-level precision. High performance metals, such
as titanium alloys, nickel superalloys, tool steels, stainless steels, etc. can benefit from this
process. Coupling the additive and the subtractive processes into a multi-axis workstation,
the hybrid process, can produce and repair metal parts with accuracy. The surface quality
of the final product is similar to the industrial milling capability. To achieve such a system,
issues of the metal deposition process and the automated process planning of the hybrid
manufacturing process will be discussed.",,,,,,
"['Barua, Shyam', 'Sparks, Todd', 'Liou, Frank']",2021-09-30T13:16:00Z,2021-09-30T13:16:00Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88229', 'http://dx.doi.org/10.26153/tsw/15170']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition process', 'low-cost', 'vision system', 'melt pool size']",Development of a Low Cost Imaging System for a Laser Metal Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7020f0df-0e34-4c3e-8bdd-9caa988492a6/download,University of Texas at Austin,"The size of the melt pool created by the laser is one of the most important quality characteristic
in a laser metal deposition process. This paper discusses the development of a low-cost vision
system to automatically determine the size of the melt pool for in-process control. To cope
with the intense infrared signal from the laser and melt pool, external ultraviolet illumination
is paired with narrow bandpass filters on a usb microscope to achieve a clear image of the melt
pool. The sensitivity of the melt pool to changes in system parameters and various substrate
materials are also evaluated.",,,,,,
"['Hammond, C.', 'Greenstreet, J.', 'Gomez, W.', 'Dang, R.', 'Tate, J.']",2023-03-29T16:22:34Z,2023-03-29T16:22:34Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117678', 'http://dx.doi.org/10.26153/tsw/44557']",eng,2022 International Solid Freeform Fabrication Symposium,Open,SLA resin,Development of a Low Thermal Expansion Sla Resin for Nickel Plating Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd18c7fb-6863-4697-8893-ed9ec969f3f7/download,,"Stereolithography additive manufacturing is a method of producing parts by stacking layers 
of a photopolymer resin cured by exposure to UV light . This method of additive manufacturing 
gives great resolution, but often lacks the material properties of other techniques. One method to 
increase part performance is the addition of a thin nickel plating to increase strength, heat 
deflection, and chemical resistance. No solution has been proposed for using nickel-coated parts 
in harsh environments where the large difference in thermal expansion rates between the nickel 
plating and base resin cause internal stresses to form. The excellent chemical resistance of the 
nickel plating would also allow these parts to be used in high-temperature, oxygen-rich 
environments such as those presented in life support systems. Through the development of a high-
performance nanocomposite SLA resin, we hope to achieve parts with good mechanical properties 
and a CTE similar to nickel.",,,,,,
"['Song, Xuan', 'Pan, Yayue', 'Chen, Yong']",2021-10-07T18:21:04Z,2021-10-07T18:21:04Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88499', 'http://dx.doi.org/10.26153/tsw/15433']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'multi-direction', 'parallel kinematic machine', 'fused deposition modeling', 'building-around-inserts']",Development of a Low-Cost Parallel Kinematic Machine for Multi-Directional Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ce96c745-5475-4880-b1ad-b58807f89b39/download,University of Texas at Austin,"Most additive manufacturing (AM) processes are layer-based with three linear motions in the X, Y and Z
axes. However, there are drawbacks associated with such limited motions, e.g. non-conformal material
properties, stair-stepping effect, and limitations on building-around-inserts. Such drawbacks will limit
additive manufacturing to be used in more general applications. To enable 6-axis motions between a tool
and a work piece, we investigate a Stewart mechanism and developed a low-cost prototype system for
multi-directional additive manufacturing processes such as the Fused Deposition Modeling (FDM) and
CNC Accumulation. The technical challenges in developing such an AM system are discussed including
the hardware design, motion planning and modeling, platform constraint checking, tool motion simulation,
and platform calibration. Several test cases are performed to illustrate the capability of the developed
multi-directional additive manufacturing system.",,,,,,
"['Sparks, Todd', 'Tang, Lie', 'Liou, Frank']",2021-09-28T19:02:57Z,2021-09-28T19:02:57Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88155', 'http://dx.doi.org/10.26153/tsw/15096']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['vision system', 'melt pool tracking', 'laser metal deposition', 'temperature feedback control system']",Development of a Melt Pool Tracking Vision System for Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5dcadaa9-4c4b-433f-b0a5-be518fb4e1ad/download,University of Texas at Austin,"This paper chronicles the development of a vision system for tracking melt pool morphology in the laser metal deposition process. This development is to augment an existing
temperature feedback control system. Monitoring both the temperature and shape of the
melt pool is necessary because of the effects of local geometry on the cooling rate at the melt
pool. Temperature feedback alone cannot accommodate this effect without complex process
planning. The vision system’s hardware, software, and integration into the laser deposition
system’s controller is detailed in this paper. Preliminary testing and the effects on deposition
quality is also discussed.",,,,,,
"['Lammers, S.', 'Lieneke, T.', 'Zimmer, D.']",2021-12-01T22:04:28Z,2021-12-01T22:04:28Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90631', 'http://dx.doi.org/10.26153/tsw/17550']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['support structures', 'process parameters', 'design guidelines', 'laser powder bed fusion']",Development of a Method to Derive Design Guidelines for Production-suitable Support Structures in Metal Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90af2513-87c7-445f-87c8-0b725299aeff/download,University of Texas at Austin,"Solid support structures in metal laser powder bed fusion have a significant influence on the economic
applicability, component quality and process stability and represent a central challenge for widespread
industrial use. As the connection of the components to the building platform by supports is essential,
the negative effects must be minimized at the same time as the supporting effect is optimized. Within the
scope of this study, a standardized method is developed that allows the investigation of several support
structures and parameters with regard to their influence on the target variables: component quality, process
efficiency and stability. In addition to the proof of general suitability, the applicability is investigated
using so-called standard elements. Based on the experimental results, design guidelines are derived, which
will serve as a basis for decision-making during the selection of support structure for an individual
application.",,,,,,
"['Zhou, Chi', 'Chen, Yong', 'Yang, Zhigang', 'Khoshnevis, Behrokh']",2021-10-04T20:26:44Z,2021-10-04T20:26:44Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88339', 'http://dx.doi.org/10.26153/tsw/15278']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'multi-material fabrication', 'bottom-up projection', 'part separation']",Development of a Multi-Material Mask-Image-Projection-Based Stereolithography for the Fabrication of Digital Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/563335aa-9fb8-4bb7-961f-f9bd8662c63e/download,University of Texas at Austin,"Digital materials such as the ones shown by Objet’s Connex family demonstrate that a new material with
desired characteristics can be achieved by combining two different base materials with various
concentrations and structures. We investigate the feasibility of using additive manufacturing processes
based on digital mask projection in the fabrication of such digital materials. A multi-material mask-image-projection-based Stereolithography process has been developed. The related challenges on the
development of such a process are identified. Our approaches to address such challenges are presented. A
testbed has been developed to fabricate component with designed digital materials. Experimental results
illustrate desired material properties can be achieved based on the developed process. Several multi-material designs have been produced to highlight the capability of this promising technology for
fabricating three-dimensional, multi-material objects with spatial control over placement of both material
and structure. The limitations and challenges for future development have also been identified.",,,,,,
"['Jalui, Sagar S.', 'Zargar, Seyed Hossein', 'Moroney, Sheila', 'Putz, Marcus', 'Taylor, Mychal', 'Hatch, Serah', 'Manogharan, Guha']",2023-02-10T14:11:20Z,2023-02-10T14:11:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117450', 'http://dx.doi.org/10.26153/tsw/44331']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Conformal printing', 'test artifact', 'dual-DfAM', 'material extrusion', 'parametric design']",Development of a Novel Test Artefact for Conformal Material Extrusion Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77f485f7-b2d2-4592-934b-0562d734f030/download,,"Additive manufacturing (AM) allows for free complexity. However, the layer-by-layer 
manufacturing method traditionally relies on a G-code input to the machine, representing 2D 
planar slices of each layer, which eventually combines to represent the net-shape 3D geometry. 
Through modification of existing slicer software, thus modifying the G-code input to the machine, 
non-planar (conformal) shells can be generated on top of a traditional planar scaffolding. The 
objective of this work is to design a novel test artifact to aid in the creation of design rules and to 
identify machine limitations for conformal printing. With the use of non-conventional design 
features using trigonometric (sine) surfaces, this test artifact would allow for deeper insights into 
the print quality of organic shapes made possible using a commercial, low-cost, material extrusion 
3D printer. It would also enable the creation of design rules for conformal printing to push forward 
the true dual-Design for Additive Manufacturing (dual-DfAM) potential.",,,,,,
"['Liou, F.W.', 'Zhang, J.', 'Agarwal, S.', 'Laeng, J.', 'Stewart, J.']",2019-09-23T16:36:40Z,2019-09-23T16:36:40Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75959', 'http://dx.doi.org/10.26153/tsw/3058']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Precision,Development of A Precision Rapid Metal Forming Process 362,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8a940ae-8621-4465-885f-579a9d9b6b77/download,,This paper presents the important issues pertaining to the development of a precision rapid metal forming process. A five-axis configuration provides a flexible building capability to produce free-form fabrication capability. The laser cladding process is able to produce functional mechanical parts and machining capability is able to produce industrial grade surface quality. A machine configuration that combines the laser cladding and CNC machining processes is presented. The related parameters and components are discussed.,"This research was supported by the National Science Foundation Grant Number DMI-9871185, Missouri Research Board, and a grant from the Missouri Department of Economic Development through the MRTC grant.",,,,,
"['Watson, J.K.', 'Taminger, K.M.', 'Hafley, R.A.', 'Petersen, D.D.']",2019-10-24T18:22:37Z,2019-10-24T18:22:37Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77418', 'http://dx.doi.org/10.26153/tsw/4507']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Fabrication,Development of a Prototype Low-Voltage Electron Beam Freeform Fabrication System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ff5261cb-b479-4ae0-bc75-e74f43141f71/download,,"NASA’s Langley Research Center and Johnson Space Center are developing a solid
freeform fabrication system utilizing an electron beam energy source and wire feedstock. This
system will serve as a testbed for exploring the influence of gravitational acceleration on the
deposition process and will be a simplified prototype for future systems that may be deployed
during long-duration space missions for assembly, fabrication, and production of structural and
mechanical replacement components. Critical attributes for this system are compactness,
minimal mass, efficiency in use of feedstock material, energy use efficiency, and safety. The use
of a low-voltage (<15kV) electron beam energy source will reduce radiation so that massive
shielding is not required to protect adjacent personnel. Feedstock efficiency will be optimized
by use of wire, and energy use efficiency will be achieved by use of the electron beam energy
source. This system will be evaluated in a microgravity environment using the NASA KC-135A
aircraft.",,,,,,
"['Stephen, A.O.', 'Dalgarno, K.W.', 'Munguia, J.']",2021-10-07T15:25:32Z,2021-10-07T15:25:32Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88480', 'http://dx.doi.org/10.26153/tsw/15414']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'quality system', 'process monitoring', 'polymer based']",Development of a Quality System for Polymer Based Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24856157-d8b7-4ffb-8677-bdb91a0ac07c/download,University of Texas at Austin,"The aim of this study is to develop a quality system for selective laser sintering, based
on defining a minimum set of tests to qualify a build. MFI, impact and flexural tests were
assessed, along with density, dimensional measurements and SEM. A benchmark part was
designed for manufacture to track changes in key parameters from build to build, and tests on
this validated against ISO standards. It is concluded that a combination of measures of
flexural modulus, density and impact strength can be used for process monitoring and to infer
the quality of a build in SLS process.",,,,,,
"['Birmingham, B.R.', 'Tompkins, J.V.', 'Zong, G.', 'Marcus, H.L.']",2018-04-19T17:39:04Z,2018-04-19T17:39:04Z,1992,Mechanical Engineering,doi:10.15781/T25H7CB2F,http://hdl.handle.net/2152/64392,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SLS', 'SLRS']",Development of a Selective Laser Reaction Sintering Workstation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd929ae1-5d22-4125-b243-1ad56fc5bd4f/download,,"The purpose of this paper is to describe the design and operation
of a Selective Laser Reaction Sintering workstation developed at The
University of Texas. The workstation allows the study of solid freeform
fabrication of reaction sintered materials on a research scale. The
mechanical and control systems of the workstation are detailed, and
Selective Laser Reaction Sintering as a technique is discussed including
example material systems that are currently under study.",,,,,,
"['Forderhase, Paul', 'McAlea, Kevin', 'Booth, Richard']",2018-11-02T16:21:51Z,2018-11-02T16:21:51Z,1995,Mechanical Engineering,doi:10.15781/T2S757482,http://hdl.handle.net/2152/69336,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['polymer industry', 'SLS', 'fully-dense functional prototypes']",The Development of a SLS Composite Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e56ab381-7c0f-440b-acc4-ce703aa8c9ba/download,,"The development of a commercial SLS nylon-based composite material (LNC 7000) is
described. Nylon composite candidate systems with different volume fractions of a
number of glass fiber and glass bead reinforcements were screened. It was found that fully
dense SLS parts with excellent mechanical properties could be made from a number of
reinforced nylon materials. An optimized material containing 29 volume percent 35 Ilm
diameter glass beads was selected based on the processing behavior and mechanical
properties of the candidate systems. The performance of this optimized material is
described. In addition, complementary aspects of the composite nylon and unreinforced
nylon materials (LN 4010 and LNF 5000) are discussed.",,,,,,
"['Quinn, Paul', ""O'Halloran, Sinead"", 'Ryan, Catriona', 'Pamell, Andrew', 'Lawlor, Jim', 'Raghavendra, Ramesh']",2021-11-18T17:58:57Z,2021-11-18T17:58:57Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90448', 'http://dx.doi.org/10.26153/tsw/17369']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['metal additive manufacturing', 'powder bed fusion', 'in-situ process monitoring', 'defect detection']",Development of a Standalone In-Situ Monitoring System for Defect Detection in the Direct Metal Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/94d10d0f-99fd-4ce0-96f4-23917f5b6b59/download,University of Texas at Austin,"Direct metal laser sintering (DMLS) is a powder bed fusion (PBF) additive manufacturing process
commonly used within the medical device and aerospace industries where regulations drive the requirement for
stringent quality control. Using in-situ monitoring, the identification of defects, as well as the geometric and
dimensional measurement of the layers throughout the build allows for greater quality control, as well as a
reduction in the requirement for ex-situ measurement. A standalone monitoring system for the EOS M280 is
presented in this research, allowing for the build process to be monitored layer-by-layer. The system images the
build area after powder deposition and after laser exposure allowing for the identification of inefficiencies in both
the powder deposition and the laser exposure. The system has proven to be capable to identify in build defects
and work is ongoing to develop an automated program to identify these defects and notify the operator in real
time.",,,,,,
"['Yang, Chen-Wei', 'Kuan, Alexander', 'Li, Sheng-Yen', 'Lu, Yan', 'Kim, Jaehyuk', 'Cheng, Fan-Tien', 'Yang, Haw-Ching']",2024-03-27T16:12:44Z,2024-03-27T16:12:44Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124504', 'https://doi.org/10.26153/tsw/51112']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'data integration testbench', 'NIST']","Development of a Testbench for Additive Manufacturing Data Integration, Management, and Analytics",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0d044f4-ec29-4c42-a1c6-753c018fbdac/download,University of Texas at Austin,"The NIST Additive Manufacturing (AM) Data Integration Testbench is a platform
designed to evaluate data models, communication methods, and data analytics for AM
industrialization. This paper describes a reference framework for AM data integration, named
AMIF, and the design of the testbench based on AM Integration Framework (AMIF) for testing
the integration of in-process data acquisition, real-time feature extraction, process control, and
predictive models under a data management system. A specification of this testbench is developed
to manage and stream voluminous data captured by high-speed cameras and performing data
analytics using common information models and functional interfaces. The integration of the data,
models, and computer tools sends operational decisions to an AM machine in real time. On top of
the real-time control functions, AM data integration with MES and ERP systems is also included
using a high-performance data warehouse for long-term data archiving and metadata management.
The architecture of this testbench is illustrated in this work. AMIF can guide AM practitioners and
system integrators to build their integrated AM manufacturing systems for production. The NIST
AM testbench’s plug-and-play features allow both internal and external researchers and developers
to assess the effectiveness of their individual data models, data analytics, and decision-making
algorithms on the systems engineering level.",,,,,,
"['Obielodan, John', 'Helman, Joshua', 'Grumbles, Andrew']",2021-11-09T20:38:35Z,2021-11-09T20:38:35Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90161', 'http://dx.doi.org/10.26153/tsw/17082']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'biocomposite', 'thermoplastics', 'polylactic acid', 'PLA', 'organosolv lignin', 'filament extrusion']",Development of a Thermoplastic Biocomposite for 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99056ed5-8030-429e-b528-cae6945553a4/download,University of Texas at Austin,"Organosolv lignin, a natural cross-linked phenolic wood polymer is a by-product of the
pulping process in the paper industry. It is a renewable organic natural product with potential
application in many areas. It has attractive properties that make it a potential candidate for
fabricating useful parts using 3D printing. Also, polylactic acid (PLA), a biodegradable
thermoplastic derived from renewable sources is widely used in 3D printing polymer parts. This
work seeks to study the technical viability of extruding different blends of PLA and organosolv
lignin into filaments for 3D printing useful objects. Filament extrusions using different blends
were evaluated. Also, the mechanical properties of printed test samples are presented. Viable
blends of the biocomposite for 3D printing has the potential to provide an added-value to lignin
for expanded use in many applications.",,,,,,
"['Eschner, N.', 'Weiser, L.', 'Häfner, B.', 'Lanza, G.']",2021-11-15T21:56:12Z,2021-11-15T21:56:12Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90284', 'http://dx.doi.org/10.26153/tsw/17205']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['acoustic process monitoring', 'in-process integration', 'acoustic measurement', 'selective laser melting', 'design of experiments']",Development of an Acoustic Process Monitoring System for Selective Laser Melting (SLM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/2350ce7e-dbc9-41bd-a79d-31481de65a98/download,University of Texas at Austin,"The current selective laser melting (SLM) process lacks both process quality and reproducibility. Recent
research focuses on the integration of optical measuring technology, but acoustic sensors also seem promising.
Initial results on acoustic methods show their suitability. The further processing of the data still shows difficulties,
mostly due to the high sample rate. In this work a concept for an acoustic process monitoring system is developed
and integrated into the process. First results show its capability to distinguish different process qualities.
For this purpose, various configurations for in-process integration of acoustic measurement techniques
are discussed and evaluated. The most promising structure-borne sound concept is integrated and tested in a test
bed. In a Design of Experiments for specific parameter selection, cubes with different process qualities are
produced, and the acoustic signatures are evaluated. For a first prove of concepts a Neuronal Network is trained
to classify three different laser classes. Therefore, different NN topologies were tested and the best-found solution
had a precision of more than 90%.",,,,,,
"['Smith, P.C.', 'Rennie, A.E.W.']",2021-09-23T22:21:00Z,2021-09-23T22:21:00Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88038', 'http://dx.doi.org/10.26153/tsw/14979']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Additive Layer Manufacturing', 'design for rapid manufacture', 'selection tool', 'creative industry']",Development of an Additive Layer Manufacturing (ALM) Selection Tool for Direct Manufacture of Products,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4f1074e-5800-4213-be1a-44f692f0992c/download,,"Advancements in Additive Layer Manufacturing (ALM) technology and a broader knowledge
base of process and material capabilities make ALM increasingly, a more valid manufacturing
option.
Small creative industry and industrial designers in the UK, as well as experienced engineers,
can benefit from the freedom from design, manufacture and distribution constraints that ALM
technology offers, yet they are unaware of the opportunities available.
This paper present a method for selecting an ALM technology as a manufacturing method,
based on a part specification, as an ALM selection tool. Selecting appropriate processes,
materials and giving design for rapid manufacture advice are part of the recommendations offered
from this ALM selection tool.",,,,,,
"['Inamdar, Asim', 'Magana, Marco', 'Medina, Frank', 'Grajeda, Yinko', 'Wicker, Ryan']",2020-03-05T19:33:55Z,2020-03-05T19:33:55Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80146', 'http://dx.doi.org/10.26153/tsw/7167']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Multiple Material Stereolithography,Development of an Automated Multiple Material Stereolithography Machine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7f27fc0-a755-4931-8dbe-0a910a4714b3/download,,"An automated Multiple Material Stereolithography (MMSL) machine was developed by
integrating components of a 3D Systems 250/50 stereolithography (SL) machine in a separate
stand-alone system and adapting them to function with additional components required for
MMSL operation. We previously reported retrofitting a 250/50 SL machine with multiple vats
to accommodate multiple material fabrication for building a wide variety of multi-material
models (Wicker et al., 2004). In the MMSL retrofit, spatial constraints limited the multiple vats
located circumferentially on a vertical rotating vat carousel to cross-sectional areas of
approximately 4.5-inches by 4.5-inches. The limited build size of the retrofitted 250/50
motivated the full development of a new system with multiple material build capabilities
comparable to the build envelope of the original 250/50 machine. The new MMSL machine
required fabrication of a large system frame, incorporating various 250/50 components and
software, and adding a variety of new components and software. By using many existing
components and software, the previous engineering development of 3D Systems could be
directly applied to this new technology. Components that were transferred from an existing
250/50 to the MMSL machine included the complete optical system (including the optics plate
with laser, mirrors, beam expander, scanning mirrors, and focusing lens), the rim assembly
(including the laser beam profilers), the associated controllers (computer system, scanning mirror
controller, power supply-vat controller) and the wiring harness. In addition to the new frame, the
MMSL machine required the development of a new rotating vat carousel system, platform
assembly, multi-pump filling/leveling system, and a custom LabVIEW® control system to
provide automated control over the MMSL process. The overall operation of the MMSL system
was managed using the LabVIEW® program, which also included controlling a new vat leveling
system and new linear and rotational stages, while the 3D Systems software (Buildstation 4.0)
was retained for controlling the laser scanning process. As a demonstration of MMSL
technology, simple multi material parts were fabricated with vertically and horizontally oriented
interfaces. The fully functional MMSL system offers enormous potential for fabricating a wide
variety of multiple material functional devices.",,,,,,
"['Deppe, G.', 'Lindemann, C.', 'Koch, R.']",2021-10-21T20:28:49Z,2021-10-21T20:28:49Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89439,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'MRO workflows', 'aerospace']",Development of an Economic Decision Support for the Application of Additive Manufacture in Aerospace,Conference paper,https://repositories.lib.utexas.edu//bitstreams/428b9cb8-7e52-4ef8-8bbd-e398eafa5024/download,University of Texas at Austin,"Additive Manufacturing offers a high potential in aerospace industry due to its freedom of
design and the ability to manufacture complex and lightweight parts. The low number of
units, high quality standards and fast response time are special challenges that have to be met
especially in the Maintenance, Repair and Overhaul sector. Thus, companies have to decide at
which point it is economic to apply Additive Manufacturing. However, companies lack
experience on this new technology. This is why a tool is required that takes into account the
above mentioned crucial points and supports the decision process. The paper analyzes
aviation’s characteristics with regard to Additive Manufacturing. The structure of current
MRO repair workflows is investigated to identify a feasible application for Additive
Manufacturing. Additionally the supply chain will be examined to indicate the benefit which
the technology can generate in this highly demanding field. The findings are integrated into a
methodology that supports the decision whether to apply Additive Manufacturing on the basis
of costs, time and quality.",,,,,,
"['Hilton, Zachary T.', 'Newkirk, Joseph W.', ""O'Malley, Ronald J.""]",2021-11-10T22:37:26Z,2021-11-10T22:37:26Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90195', 'http://dx.doi.org/10.26153/tsw/17116']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['engineering diagram', 'stainless steel', 'stainless steel alloys', 'additive manufacturing']",Development of an Engineering Diagram for Additively Manufactured Austenitic Stainless Steel Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9aa05542-8660-473a-8388-e485d44231b4/download,University of Texas at Austin,"Austenitic stainless steels are the most widely applied types of stainless steels, due to their good
weldability and high corrosion resistance. A number of engineering diagrams exist for the
purpose of providing insight into the behavior of these steels. Examples of these diagrams are
constitution diagrams (aka Schaeffler Diagrams) which are used to approximate the solidification
path of the alloy and the amount of retained ferrite in the solidified matrix. Other diagrams are
the Suutala diagram, which approximates cracking susceptibility, and microstructural maps,
which predict the solidification path by varying a processing parameter, such as cooling rate. By
combining these diagrams, a much more concrete conclusion can be made as to the behavior of a
particular steel. This approach could be used to determine differences in behaviors between two
different compositions. The developed diagram would be intended for use with rapid
solidification phenomena as observed in the selective laser melting process.",,,,,,
"['Lohn, Johannes', 'Kummert, Christina', 'Schmid, Hans-Joachim']",2021-11-02T18:36:19Z,2021-11-02T18:36:19Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89863,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser sintering machine', 'laser sintering', 'processing']",Development of an Experimental Laser Sintering Machine to Process New Materials Like Nylon 6,Conference paper,https://repositories.lib.utexas.edu//bitstreams/74448d92-87e1-402d-b611-5d6db665ab57/download,University of Texas at Austin,"Selective Laser Sintering (SLS) is an Additive Manufacturing technology which allows the
production of functional polymer parts. Conventionally, Nylon 12 (PA 12), Polyamide 11 (PA 11),
glass- or aluminum filled materials are used. Those materials do not always meet the requirements
for direct production of serial parts by laser sintering. For the so called “Direct Manufacturing” of
high quality, functional parts, the laser sintering process needs to be further developed and the
choice of materials and needs to be expanded.
During this research, a laser sintering machine for material qualification has been built up. The
advantages are an optimized software solution, an innovative optical system with an adjustable
laserspot, an alternative powder coating system and an improved temperature control.
The functionality of the test equipment is proved with the standard material PA2200 and the new
laser-sintering-material, Polyamide 6X (PA6X) is investigated. The required process parameters
for processing PA6X are derived and the mechanical properties are determined by tensile tests.",,,,,,
"['Uhlmann, Eckart', 'Krohmer, Erwin', 'Hohlstein, Felix', 'Reimers, Walter']",2021-11-04T13:42:12Z,2021-11-04T13:42:12Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89957,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['strain evaluation', 'in situ', 'residual stress', 'selective laser melting', 'experimental test setup']",Development of an Experimental Test Setup for In Situ Strain Evaluation During Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/41cce3aa-8fe7-4878-ba2f-bef308030c15/download,University of Texas at Austin,"Selective Laser Melting (SLM) is an Additive Manufacturing (AM) process which still
underlies a lack of profound process understanding. This becomes obvious when deformation and
crack formation can be observed in SLM parts due to residual stresses. Controlling residual
stresses is therefore an important topic of recent research in AM of metals. In order to minimize
residual stresses further knowledge considering their cause and physical correlations of process
parameters needs to be generated. In this paper an approach of measuring strains layer by layer
during the SLM process by means of in situ X-ray diffraction is presented. For this purpose an
experimental test setup is being constructed at the Technische Universität Berlin. The system
requirements and operating principles are discussed in this paper. Furthermore, details of the
current progress of the construction are highlighted.",,,,,,
"['Ma, Guohua', 'Crawford, Richard H.']",2019-10-24T18:02:58Z,2019-10-24T18:02:58Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77412', 'http://dx.doi.org/10.26153/tsw/4501']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Integrated Graphical,The Development of an Integrated Graphical SLS Process Control Interface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7d118629-8c0d-4ddf-9711-9438f83001bd/download,,"This paper presents the systematic development of a man/machine interface for Selective
Laser Sintering. The interface developed integrates geometry design, process data/code generation, power
control and communication in a graphical environment. The objective of this interface is to
provide high flexibility and robustness to researchers to meet their special needs. For example,
the user can generate laser power profiles of any shape, or control the laser power by PWM or an
analog voltage. The control code for the machine is automatically generated with minimum
human input. Currently the interface is limited to use on a single layer machine, but can be
easily modified for multi-layer machines. LabVIEW™ is employed as the developing platform.",,,,,,
"['Cunico, Marlon Wesley Machado', 'Cavalheiro, Patrick Medeiros', 'de Carvalho, Jonas']",2021-11-04T18:28:15Z,2021-11-04T18:28:15Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89999', 'http://dx.doi.org/10.26153/16920']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'smoothing process', 'dimensional evaluation']",Development of Automatic Smoothing Station Based on Solvent Vapour Attack for Low Cost 3D Printers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9cc0f080-e263-4d42-be2b-9c9300f5af09/download,University of Texas at Austin,"Along the last years, 3d printing has been playing a new and important role in several market
segments. As consequence, finishing methods have been developed and applied in order to improve
surface roughness and mechanical strength. One of these methods is the solvent vapour attack.
Nonetheless, this process is still manual and might lead to object deformation or structural
damages. For that reason, the main goal of this work is to present a new approach that was
implemented in automatic smoothing station. In this new approach, a close-looping control system
identifies the vapour attack level in addition to controlling drying time and number of times that
cycle is repeated. By the end, this proposal was identified to advances in 3d printing field, being a
next step for domestic and distributed manufacturing.",,,,,,
"['Fuesting, T.', 'Brown, L.', 'Das, S.', 'Harlan, N.', 'Lee, G.', 'Beaman, J.J.', 'Bourell, D.L.', 'Barlow, J.W.', 'Sargent, K.']",2018-11-08T19:59:10Z,2018-11-08T19:59:10Z,1996,Mechanical Engineering,doi:10.15781/T2BZ61T84,http://hdl.handle.net/2152/69918,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['shrinkage', 'compositions', 'volumetric comparison']",Development of Direct SLS Processing for Production of Cermet Composite Turbine Sealing Components- Part II,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15e5f7a7-9073-4f67-a701-54f5c9782033/download,,,,,,,,
"['Oakes, Thomas', 'Kulkarni, Parimal', 'Landers, Robert G.', 'Leu, Ming C.']",2021-09-28T19:25:51Z,2021-09-28T19:25:51Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88160', 'http://dx.doi.org/10.26153/tsw/15101']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Freeze-form Extrusion Fabrication', 'extrusion-on-demand', 'ceramic FEF']",Development of Extrusion-on-Demand for Ceramic Freeze-Form Extrusion Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/06020cfe-6dc9-4429-a5c0-e29ff9e8fe3e/download,University of Texas at Austin,"In the Freeze-form Extrusion Fabrication (FEF) process, extrusion-on-demand (EOD)
refers to the ability to control the start and stop of paste extrusion on demand and is vital
to the fabrication of parts with complex geometries. This paper describes the
development of EOD for ceramic FEF through modeling and control of extrusion force,
selection of appropriate process parameters, and a dwell technique for start and stop of
extrusion. A general tracking controller with integral action is used to allow tracking of a
variety of reference forces while accounting for the variability in the paste properties.
Experiments are conducted to model the process and tune the controller. The developed
technique for EOD is demonstrated to fabricate a number of cross sections and three-dimensional parts from alumina paste.",,,,,,
"['Lee, Kwan H.', 'Park, Joung O.']",2019-09-23T16:05:45Z,2019-09-23T16:05:45Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75950', 'http://dx.doi.org/10.26153/tsw/3049']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Lamination,Development of Freeform Master I – a Desktop RP Machine Based on a New Sheet Lamination Process 283,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a775dcd-fd9d-4117-8f64-876b14af1ce9/download,,"A novel process was developed for building Rapid Prototyping(RP) parts using a sheet lamination technique. The building process of existing sheet lamination RP machines consist of the following steps : feeding, lamination and cutting. In this process, the laminated part of an object is often scratched by a cutter or damaged by a laser beam due to the cutting operation after the lamination step. In addition, decubing of the unused portion from the laminated block is difficult. In the new process, however, cutting is performed before lamination. The cutting operation takes place while a paper sheet is firmly attached, using electrostatic force on the plate. Then liquid glue is applied only to the calculated region of the given contour for lamination. This
new process aims to manufacture a $2k RP machine, what we call the Freeform Master I and can use A4 size or letter size sheets of paper. A prototyping machine that demonstrates the concept design was built and further research issues are discussed",,,,,,
"['Leu, Ming C.', 'Garcia, Diego A.']",2021-10-07T18:33:50Z,2021-10-07T18:33:50Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88501', 'http://dx.doi.org/10.26153/tsw/15435']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Freeze-form Extrusion Fabrication', 'sacrificial material', 'three-dimensional ceramic parts', 'methyl cellulose', 'alumina', 'computer-aided design']",Development of Freeze-Form Extrusion Fabrication with Use of Sacrificial Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/afd6068b-fa27-4cb5-b31f-ae775763cdb0/download,University of Texas at Austin,"The development of Freeze-form Extrusion Fabrication (FEF) process to fabricate three-dimensional (3D) ceramic parts with use of sacrificial material to build support sections during
the fabrication process is presented in this paper. FEF is an environmentally friendly, additive
manufacturing process that builds 3D parts in a freezing environment layer-by-layer by computer
controlled extrusion and deposition of aqueous colloidal pastes based on computer-aided design
(CAD) models. Methyl cellulose was identified as the support material, and alumina was used as
the main material in this study. After characterizing the dynamics of extruding alumina and
methyl cellulose pastes, a general tracking controller was developed and applied to control the
extrusion force in depositing both alumina and methyl cellulose pastes. The controller was able
to reduce the time constant for the closed-loop system by more than 65% when compared to the
open-loop control system. Freeze-drying was used to remove the water content after the part has
been built. The support material was then removed in the binder burnout process. Finally,
sintering was done to densify the ceramic part. The fabrication of a cube-shaped part with a
square hole in each side that requires depositing the sacrificial material during the FEF process
was demonstrated.",,,,,,
"['Brackett, James', 'Yan, Yongzhe', 'Cauthen, Dakota', 'Kishore, Vidya', 'Lindahl, John', 'Smith, Tyler', 'Ning, Haibin', 'Kunc, Vlastamil', 'Duty, Chad']",2021-11-30T19:17:21Z,2021-11-30T19:17:21Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90518', 'http://dx.doi.org/10.26153/tsw/17437']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['functionally graded materials', 'large-scale additive manufacturing', 'big area additive manufacturing', 'gradient']",Development of Functionally Graded Material Capabilities in Large-scale Extrusion Deposition Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5273f619-c423-4c74-8096-3d44886d87b4/download,University of Texas at Austin,"Additive manufacturing’s (AM) layer-by-layer nature is well-suited to the production of
Functionally Graded Materials (FGM) with discrete material boundaries. Extrusion deposition is
especially advantageous since multiple nozzles easily accommodate the inclusion of additional
materials. However, discrete interfaces and sudden composition changes can limit the
functionality of a printed part through inherently weak bonding. Furthermore, same-layer
transitions are not only difficult to execute, but also further amplify structural weaknesses by
creating multiple discrete interfaces. Therefore, successfully implementing a blended, continuous
gradient will greatly advance the applicability of FGM in additive manufacturing. The pellet-fed
nature and integrated screw design of the Big Area Additive Manufacturing system enables
material mixing needed for development of this capability. Using constituent content analysis,
this study evaluates the transition behavior of a neat ABS/CF-ABS material pair and
characterizes the repeatability of the mixing and printing process, which ultimately leads to
control of site-specific material deposition and properties.",,,,,,
"['Copenhaver, Katie', 'Lamm, Meghan', 'Hubbard, Amber']",2024-03-27T16:05:31Z,2024-03-27T16:05:31Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124500', 'https://doi.org/10.26153/tsw/51108']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['porosity', 'fiber alignment', 'sustainability', 'feedstock', 'additive manufacturing']","DEVELOPMENT OF HIGHLY FILLED BIO-BASED COMPOSITES FOR SUSTAINABLE, LOW-COST FEEDSTOCK: PROCESSING EFFECTS ON POROSITY AND FIBER ALIGNMENT",Conference paper,https://repositories.lib.utexas.edu//bitstreams/56b9a10f-a732-4c7b-aa3b-8cabfc478207/download,University of Texas at Austin,"A poly(lactic acid) composite with a high loading of bio-based fibers was developed using
a combination of high-aspect ratio (AR) wood pulp and low-AR wood flour along with viscosity
modifiers to maximize mechanical performance, maintain processability, and lower the cost and
embodied energy of the resulting feedstock. An optimized composite formulation containing 40
wt.% of a blend of high- and low-AR natural fibers with a rice bran-based wax processing aid was
scaled up to produce pellet feedstock using twin screw extrusion, and materials were compression
and injection molded to investigate the effect of fiber alignment on material performance. The
feedstock was then printed on the Big Area Additive Manufacturing system at Oak Ridge National
Laboratory. Print parameters including temperature gradients, screw and gantry speeds, layer
times, and nozzle designs were varied to minimize sharkskinning, warpage, and porosity of the
final parts. A strong effect of the nozzle size on the resulting porosity was observed, and consistent
trends between decreasing porosity, increasing fiber alignment, and increasing mechanical
performance were identified after printing with different nozzles, compression molding, and
injection molding.",,,,,,
"['Groh, Barbara', 'Lee, Kwon Sang', 'Cullinan, Michael', 'Chang, Chih-Hao']",2024-03-26T20:37:09Z,2024-03-26T20:37:09Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124400', 'https://doi.org/10.26153/tsw/51008']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['roll-to-roll fabrication', 'R2R', '3D printing', 'additive manufacturing']",Development of Joint Manufacturing and In-Line Metrology System for the Patterning of 3D Holographic Structures in Roll-to-Roll Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d879c96b-da27-4991-bc42-bfffad69a4bd/download,University of Texas at Austin,"Roll-to-roll (R2R) fabrication at the micro and nano scales promises to increase
manufacturing throughput and reduce unit cost while providing avenues for unique product
applications. By exploring the potential of creating 3D structures with a single lithography step
and being able to confirm success in-situ, existing multilayer patterning error can be mitigated,
since 3D features would be created in one step rather than many. This paper demonstrates steps
being taken to combine a R2R 3D nanolithography tool and an atomic force microscopy (AFM)-
based in-line metrology tool into a functional system for patterning precise 3D structures. An
existing manufacturing system will be adapted to pattern complex structures with a flexible PDMS
mask currently being proven on stationary substrates. Modifications to the AFM system will
include a focus on imaging patterns with varying mechanical properties and tailoring the system
to include gathering mechanical information as well as imaging. By mapping surface features, the
AFM tool will identify surface imperfections and predict failure modes occurring within the 3D
structure.",,,,,,
"['Garcia, D.', 'Watanabe, K.I.', 'Marquez, L.', 'Arrieta, E.', 'Wicker, R.', 'Medina, F.']",2023-03-30T16:25:52Z,2023-03-30T16:25:52Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117704', 'http://dx.doi.org/10.26153/tsw/44583']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Inconel 625', 'Inconel 718', 'Directed Energy Deposition (DED)', 'Cladding', 'Additive  Manufacturing (AM)']",Development of Laser Cladding Procedure through Experiment and Analysis Using Powder Blown Directed Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82f9bca8-d080-4040-a8dc-9a7ae732b137/download,,"Directed Energy Deposition (DED) is one of the categories in Additive Manufacturing 
(AM) that has increased its popularity due to the technological advancements in recent years 
mainly with advancements in laser power, application of multi-materials, and capability to print 
greater dimensions. We are experimenting with a particular process in DED, cladding. For our 
experiment, we implemented a powdered feedstock (Inconel 718) which was assessed with distinct 
types of substrates in an effort to reduce the time spent on trial-and-error development of cladding 
parameters. We developed a procedure to determine a good clad interaction after an examination 
of the microstructure and interaction of single beads and a hatched area. The results demonstrate 
the ideal powers to be applied in the three substrates assessed with correlation to the dilution 
percentage where our target ranged from 10 to 30%.",,,,,,
"['Vath, Carson', 'Masum Billah, Kazi MD', 'Manogharan, Guhprasanna']",2024-03-26T20:39:12Z,2024-03-26T20:39:12Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124401', 'https://doi.org/10.26153/tsw/51009']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['hybrid additive manufacturing', 'embedded electronics', 'additive manufacturing']",Development of Multimaterial Additive Manufacturing Systems for Embedded Electronics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8779640e-dbb0-4720-b6fa-01563295df9c/download,University of Texas at Austin,"Hybrid additive manufacturing (AM) to integrate discrete material systems and structures in a
monolithic part is a growing research interest. The layer-by-layer deposition system of the AM
build process allows users to integrate multiple materials using custom made tools added to the
gantry systems. State of the art machine development efforts are highly focused on thermoplastic
based material extrusion systems. Compared to the significantly matured thermoplastic material
extrusion AM system, thermoset systems are not well positioned in the market due to the lack of
integrated tooling. This research develops a wire deposition tool that is designed to embed wire
in a photocurable thermoset. Thermoset is relatively stable and does not require heat for
implanting wire. The proposed design method has a more rapid production rate as the extrusion
process can be conducted without any interruptions. The final design was manufactured in PLA
with a traditional FDM machine allowing multiple design iterations to be made quickly. The
final design will be printed on an SLA machine for more accurate, robust parts.",,,,,,
"['Kim, Hyo Chan', 'Saotome, Tsuyoshi', 'Hahn, H. Thomas', 'Bang, Young Gil', 'Bae, Sung Woo']",2020-03-10T14:07:03Z,2020-03-10T14:07:03Z,8/27/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80205', 'http://dx.doi.org/10.26153/tsw/7224']",eng,2007 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,Development of Nanocomposite Powders for the SLS Process to Enhance Mechanical Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fe3810cf-f00a-4576-880b-548a3a2ce879/download,,"In an effort to fabricate prototypes with improved mechanical properties in the dual laser
sintering process, functionalized graphite nanoplatelets were added to the PA-12 powder to
produce a nanocomposite powder. The PA-12 powder was chosen as the matrix polymer
because it has features conducive to laser sintering such as relatively low melting temperature
and high mechanical properties. The GNPs were oxidized through a nitric acid treatment to
improve the interfacial bonding. The resulting nanocomposite powder was layered and sintered
by laser without any sign of agglomeration. Although the result is preliminary, it nevertheless
shows the suitability of the nanocomposite powder for the laser sintering process.",,,,,,
"['Manthiram, A.', 'Chi, F.', 'Johnson, F.', 'Birmingham, B.R.', 'Marcus, H.L.']",2018-05-03T17:00:51Z,2018-05-03T17:00:51Z,1993,Mechanical Engineering,doi:10.15781/T2RV0DJ0N,http://hdl.handle.net/2152/65039,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'SLS', 'SLRS', 'nanocomposites']",Development of Nanocomposites for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d624522-5147-477a-8c56-0c2562adc332/download,,"Nanocomposites in which the constituents are mixed on a nanorneter scale can
provide important advantages in the Selective Laser Sintering (SLS) and Selective Laser
Reactive Sintering (SLRS) processes. The larger surface area and grain boundaries in the
nanocolnposites compared to that in the conventional microcomposites are expected to
enhance the solid state diffusion during laser irradiation as well as during any other
subsequent processes. Our strategy is to design and develop nanocomposites in which one
nanosize cOlnponent has a lower melting point than the other nanosize component, either of
which can serve as the matrix phase. The nanoscale dispersion of the low melting
component can aid the sintering process during SLS or SLRS. Nanocomposite powders of
AI203-COOx, Ab03-NiO, A1203-CO and A1203-Ni have been synthesized by sol-gel
processing and are evaluated by SLS.",,,,,,
"['Domack, M. S.', 'Baughman, J. M.']",2020-02-17T15:06:43Z,2020-02-17T15:06:43Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80005', 'http://dx.doi.org/10.26153/tsw/7030']",eng,2004 International Solid Freeform Fabrication Symposium,Open,titanium alloy,Development of Nickel-Titanium Graded Composition Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1300705e-76f6-4dbc-aeca-ce533aee79e3/download,,"The potential of various manufacturing methods was evaluated for producing nickel-titanium
graded composition material. The selected test case examined attachment brackets that join
nickel-based metallic thermal protection systems to titanium-based launch vehicle structure. The
proposed application would replace nickel-based components with graded composition
components in an effort to alleviate service induced thermal stresses. Demonstration samples
were produced by laser direct metal deposition, flat wire welding, and ultrasonic consolidation.
Microstructure, general bond quality, and chemistry were evaluated for the components.",,,,,,
"['Guo, C.', 'Lin, F.', 'Ge, W.J.', 'Zhang, J.']",2021-10-12T22:13:21Z,2021-10-12T22:13:21Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88752', 'http://dx.doi.org/10.26153/tsw/15686']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['electron beam selective melting', 'dual-material processing', 'additive manufacturing', 'vibration driven powder']",Development of Novel EBSM System for High-Tech Material Additive Manufacturing Research,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a162b49b-3525-40f4-ac73-d20a85788ff6/download,University of Texas at Austin,"Electron beam is more appropriate for metal additive manufacturing (AM) than laser
because of its high energy converting efficiency and high absorption for various materials. It
becomes a preference for AM study of high-tech material with high melting point, high
brittleness or graded material. A novel electron beam selective melting (EBSM) system with
dual-material processing capability has been developed in Tsinghua University to meet the wide
high-tech material AM research requirement. A vibration driven powder supplier was developed
and the supplier had a high compatibility to various powders. A stable supplying rate and a
supplying accuracy less than 7.5% were obtained with the supplier. Two powders can be supplied
individually to obtain a mixture with tailored proportion for each powder layer. The mixture is
homogenous and the actual proportion is close to the desired value. In order to prolong the
spreading comb’s lifetime and avoid tooth breaking, a low deformation powder spreading device
was designed based on dual inclined combs and a one-way scraping mechanism. The system
provides exchangeable building tanks with sizes of 100 ×100 ×100 mm3
and 250 × 250 × 250
mm3, which can save powder when the part is small and the powder is expensive. The novel
EBSM system is capable of building parts with single material and has a potential of
dual-material processing.",,,,,,
"['Caprio, L.', 'Chiari, G.', 'Demir, A.G.', 'Previtali, B.']",2021-11-15T22:42:29Z,2021-11-15T22:42:29Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90300', 'http://dx.doi.org/10.26153/tsw/17221']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'high temperature', 'preheating', 'TiAl']",Development of Novel High Temperature Laser Powder Bed Fusion System for the Processing of Crack-Susceptible Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2a984381-9b12-498e-8013-344aefbc59e4/download,University of Texas at Austin,"In the industrial panorama, Laser Powder Bed Fusion (LPBF) systems enable for the near net shaping of
metal powders into complex geometries with unique design features. This makes the technology appealing for
many industrial applications, which require high performance materials combined with lightweight design or
conformal cooling channels. However, many of the alloys that would be ideal for the realisation of these
functional components are classified as difficultly weldable due to their cracking sensitivity. Currently, industrial
SLM systems employ baseplate preheating to minimise these effects although this solution is limitedly effective
along the build direction and often does not achieve high enough temperatures for the realisation of crack-free
specimen. In this work, the design and implementation of a novel inductive high temperature LPBF system is
presented. Furthermore, preliminary results regarding depositions of Titanium Aluminide alloy with and without
preheating are reported, showing the potential of the solution developed.",,,,,,
"['Cohen, Julien', 'Bourell, David L.']",2021-11-01T22:14:44Z,2021-11-01T22:14:44Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89777,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['pin fin arrays', 'pin fin geometries', 'compact heat exchangers', 'heat exchangers', 'additive manufacturing']",Development of Novel Tapered Pin Fin Geometries for Additive Manufacturing of Compact Heat Exchangers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb46853b-d18f-4690-9153-9aa7f1f34587/download,University of Texas at Austin,"Pin fin arrays are widely used to enhance forced convection heat transfer across various
industries, finding application in turbine blade trailing edges, electronics cooling, and broadly for
compact heat exchange. Fin shape greatly affects flow separation and turbulence generation, and
optimizing performance relies on this balance between increased heat transfer and increased
pressure loss along the array. Straight circular and elliptical fins are well-characterized in the
literature, and there exist a scant few studies on tapered configurations with conventional cross-sections. Recent works have investigated straight pin fins with more complex shapes. Tapered,
complex fin geometries represent an avenue for overall performance gains, but manufacturing
them is difficult and time-consuming using traditional machining processes. The unique
capabilities of additive manufacturing now allow their economical fabrication in an increasing
number of fully-dense engineering materials. This work compares 21 pin fin arrays of varying
fin cross-section, taper angle, taper profile, and array patterns using experimental and
computational methods.",,,,,,
"['Vlasea, M.L.', 'Lane, B.', 'Lopez, F.', 'Mekhontsev, S.', 'Donmez, A.']",2021-10-20T20:34:05Z,2021-10-20T20:34:05Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89356,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'additive manufacturing', 'testbed', 'real-time', 'process control']",Development of Powder Bed Fusion Additive Manufacturing Test Bed for Enhanced Real-Time Process Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ae5a890-4cad-4b7c-9fda-c14360521078/download,University of Texas at Austin,"Laser powder bed fusion (PBF) is emerging as the most popular additive manufacturing (AM)
method for producing metallic components based on the flexibility in accommodating a wide
range of materials with resulting mechanical properties similar to bulk machined counterparts, as
well as based on in-class fabrication speed. Although this approach is advantageous, the current
limitations in achieving predictable and repeatable material and structural properties, geometric
and surface roughness characteristics, and the occurrence of deformations due to residual stresses
results in significant variations in part quality and reliability. Therefore, a better understanding
and control of PBF AM processes is needed. The National Institute of Standards and Technology
(NIST) is developing a testbed to assess in-process and process-intermittent metrology methods
and real-time process control algorithms, and to establish foundations for traceable radiance-based temperature measurements that support high-fidelity process modeling efforts. This paper
will discuss functional requirements and design solutions to meet these distinct objectives.",,,,,,
"['Zhang, Xinchang', 'Cui, Wenyuan', 'Hill, Leon', 'Li, Wei', 'Liou, Frank']",2021-11-09T15:35:36Z,2021-11-09T15:35:36Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90097', 'http://dx.doi.org/10.26153/tsw/17018']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['pre-repair machining', 'component repair', 'defects', 'additive manufacturing']",Development of Pre-Repair Machining Strategies for Laser-Aided Metallic Component Remanufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d78eb058-df67-458d-8fc6-cc665f871966/download,University of Texas at Austin,"Remanufacturing worn metallic components can prolong the service life of parts that need
frequent replacement but are extremely costly to manufacture, such as aircraft titanium
components, casting dies. Additive manufacturing (AM) technology enables the repair of such
valuable components by depositing filler materials at the worn area layer by layer to regenerate
the missing geometry. In general, damaged parts would be inspected and pre-machined prior to
material deposition to remove oil, residue, oxidized layers or defects located in inaccessible
regions. Therefore, the motivation of this paper is to introduce pre-repair machining strategies for
removing contaminated materials from damaged components and materials surrounding
inaccessible defects to ensure that the target damage is repairable. The current research targets at
common failures comprising surface indentations, erosion, corrosion, wear and cracking, and the
machining strategies for each defect were proposed. Each strategy takes the 3D scanned damaged
model as input and the cut-off volume around the defects is defined by using different approaches.
Pre-repair machining toolpath and program were generated based on the defined cut-off volume
and finally, damaged parts were machined using the proposed strategies.",,,,,,
"['Snarr, Scott E.', 'Snarr, Patrick L.', 'Beaman, Joseph Jr']",2023-01-20T16:29:38Z,2023-01-20T16:29:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117262', 'http://dx.doi.org/10.26153/tsw/44143']",eng,2022 International Solid Freeform Fabrication Symposium,Open,carbon fiber,Development of Processing Parameters for the Selective Laser Sintering of Carbon Fiber Reinforced Polyphenylene,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0bd0f0a2-9f4c-40b7-a8cc-bb48824acb53/download,,"The ongoing development of processing parameters for advanced thermoplastic materials
to be fabricated via selective laser sintering (SLS) is rapidly advancing the potential industrial
applications of the manufacturing method. This research focuses on the development of SLS
processing parameters and a tooling application for carbon fiber reinforced Polyphenylene
Sulfide (CF-PPS), a composite material that is novel to SLS. A high temperature SLS research
machine was used to identify suitable processing parameters for the material along with the
tensile strength and geometrical accuracy associated with those parameters. Utilizing the
previously identified parameters, a repair mold for an electronic cable assembly was fabricated.
Mechanical tests were performed on fabricated CF-PPS parts to evaluate the performance of the
material under the mold’s normal operating conditions. The additively manufactured CF-PPS
mold was deemed viable for production and was shipped to our sponsor for further evaluation.",,,,,,
"['Yashiki, Tatsuro', 'Takagi, Tarou']",2019-10-23T14:51:51Z,2019-10-23T14:51:51Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76752', 'http://dx.doi.org/10.26153/tsw/3841']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Reverse Engineering,Development of Reverse Engineering System for Machine Engineering Using 3D Bit-Map Data,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bddcf308-03aa-4ab7-bb19-a7662f0346b1/download,,"In this paper, the authors describe a reverse engineering system, named BitCAT, for machine
engineering using 3D bit-map data obtained from CT digitizers. BitCAT can compose B-Rep CAD
models by fitting parametric primitives, such as flat planes and cylinders, onto 3D bit-map surfaces.
To find boundaries of the primitives effectively, a novel interactive “growing surface method” is
developed and applied in the system. BitCAT is also provided with a method to determine
geometric constraints between the primitives during composition processes. BitCAT can make
very useful CAD models for manipulation and NC machining, because they are properly attached
with geometrical features. A demonstration verifies the faculty and usefulness of the system.",,,,,,
"['Nolan, Thomas', 'Lian, Yongsheng', 'Sussman, Mark']",2021-11-03T21:37:14Z,2021-11-03T21:37:14Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89939,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['simulation tool', 'selective laser melting', 'additive manufacturing']",Development of Simulation Tools for Selective Laser Melting Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b5d7c07f-422e-48df-82e0-8fad6afb4df1/download,University of Texas at Austin,"Two simulations tools have been developed to simulate selective laser melting. One is based on a
multiphase flow solver with dynamic mesh adaptation and massive parallelism. The simulation
tool is based on a first-principles approach to simulate complex additive manufacturing processes
at the entire built part/component level. The developed model takes into account of heating,
melting, powder-to-solid volumetric consolidation, cooling, as well as solidification and shrinkage
that are often ignored in current simulation tools. The second tool is to solve the heat equation only
without considering the flow field and volumetric changes. In both tools laser is modeled as a heat
source. The reported work is our first step toward the development of a complete software suite
that can be executed rapidly on workstations and clusters with accelerators. The simulation tool
can provide AM practitioners and researchers from industry and academic a fast and accurate
simulation-based approach to replace current trial-and-error based practices in industry for process
and material development.",,,,,,
"['Kim, Seongyeon', 'Kim, Kiseong', 'Shin, Jongho']",2024-03-26T20:41:02Z,2024-03-26T20:41:02Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124402', 'https://doi.org/10.26153/tsw/51010']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['deep reinforcement learning', 'soft gripper', 'additive manufacturing']",Development of Soft Gripper Pneumatic Control System Based on Deep Reinforcement Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/32d64e3e-1b79-4351-9b46-fd5140219332/download,University of Texas at Austin,"As interest in soft grippers soared, many studies have been performed to control the soft gripper. For the
soft gripper control, a soft gripper model is required first. Usually, the soft gripper modeling has been done
through finite element analysis, which takes lots of time and is effective only in limited situations. Therefore,
research on deep learning-based modeling with a small amount of FEM results has been extensively conducted,
and some satisfactory results have been reported. However, since the model is expressed in the form of a neural
network, it is difficult to utilize general control methods, so research on optimal control or deep reinforcement
learning is being attempted. In this study, we propose a pneumatic control system for the soft gripper control
based on the DRL. To this end, the soft gripper and DRL-based controller are directly developed, and experiments
are performed and the results are analyzed.",,,,,,
"['Brabazon, Dermot', 'Kennedy, Donal', 'Tyrell, Michael']",2021-10-01T00:06:54Z,2021-10-01T00:06:54Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88303', 'http://dx.doi.org/10.26153/tsw/15244']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'direct shell production', 'three dimensional printing', 'mould']",Development of Technique for 3D Printed Mould Intricate Rapid Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/364a0d1e-db88-4a3f-b969-cf8259834522/download,University of Texas at Austin,"The development of rapid prototyping (RP) technologies has proven highly significant in the
efforts to reduce production times for a number of casting processes. Although rapid prototyping
technologies have most commonly be used to produce patterns for investment and sand casting
this study demonstrated the use of direct shell production casting using three dimensional
printing technology. Statistical methods as well as thermal, visual and dimensional analysis were
also applied in order to optimise this rapid casting (RC) process for thin wall non-ferrous parts.
Mould dimensions within ± 0.22 mm were achieved with the developed technique. Higher melt
temperatures and pouring pressures produced castings with better dimensional accuracy. Mould
temperature was not found to affect the casting dimensional accuracy significantly. The results
allow for better dimensional specification of CAD file geometry for the rapid casting process.",,,,,,
"['Mohammed, Mazher Iqbal', 'Ridgway, Mark Gerard', 'Gibson, Ian']",2021-11-08T21:05:34Z,2021-11-08T21:05:34Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90040', 'http://dx.doi.org/10.26153/tsw/16961']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'resection guide', 'radius', '3D modelling', 'implant']",Development of Virtual Surgical Planning Models and a Patient Specific Surgical Resection Guide for Treatment of a Distal Radius Osteosarcoma using Medical 3D Modelling and Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e522a59c-0767-4b93-bc53-a0ebcf23fa35/download,University of Texas at Austin,"In this study we will assess the design and fabrication of a patient-specific resection guide to
augment surgical procedures, such as bone grafts and implant placement. Medical imaging data was
used to form a 3-dimensional, digital template model of the target anatomy to incorporate surface
topography information into the guide. The surgical guide was then designed to incorporate slots for
bone cutting, holes for drilling of fixation points, and an optimised geometry which ensure ease of
placement and use. The final device was then manufactured using additive manufacturing, to
accurately replicate the complex surface topography and design features. To validate the design, the
target patient anatomy was replicated using additive manufacturing and a ‘mock’ surgery was
performed to assess the device performance. We found our design allowed for efficient placement
and use during the mock surgery, confirming the potential of the devised process as a robust
methodology for clinical implementation.",,,,,,
"['Fuesing, T.', 'Brown, L.', 'Das, S.', 'Harlan, N.', 'Lee, G.', 'Beaman, J.J.', 'Bourell, D.L.', 'Barlow, J.W.', 'Sargent, K.']",2018-11-08T19:51:27Z,2018-11-08T19:51:27Z,1996,Mechanical Engineering,doi:10.15781/T2GQ6RN2H,http://hdl.handle.net/2152/69917,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'postprocessing', 'Microstructures']",Development ofDirect SLS Processing for Production ofCermet Composite Turbine Sealing Components - Part I,Conference paper,https://repositories.lib.utexas.edu//bitstreams/04924b29-4bef-4d58-9875-9de2cf08e33a/download,,"This paper presents the development to date of SLS (selective laser sintering)
technologies for production of cermet composite turbine sealing components, the particular
application being an abrasive blade tip. The component chosen for the application is an integral
part of the low pressure turbine in a IHP'TET (Integrated High Performance Turbine Engine
Technology) demonstrator engine. Both indirect and direct SLS techniques are being developed.
Initial trials and process development involved the use of fugitive polymeric binders. Sequential
refinements were performed to develop a binderless direct SLS process. Results from mechanical
testing indicate that acceptable microstructure and properties are attainable by SLS with
substantial cost savings as compared to the currently employed production method. This is the
rust instance ofdirect SFF methods applied to a functional component",,,,,,
"['Kyogoku, H.', 'Chiba, A.', 'Hashitani, M.', 'Kimijima, T.']",2021-11-18T18:53:37Z,2021-11-18T18:53:37Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90466', 'http://dx.doi.org/10.26153/tsw/17387']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['development status', 'TRAFAM', 'Japan', 'additive manufacturing']",The Development Status of the National Project by Technology Research Assortiation for Future Additive Manufacturing (TRAFAM) in Japan,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68b7911a-5d62-44e0-8b0b-7bfb5a733330/download,University of Texas at Austin,"The Ministry of Economy, Trade and Industry (METI) of Japan established Technology Research
Association for Future Additive Manufacturing (TRAFAM) in order to develop AM technology in
FY2014. The association’s mission is twofold; to develop metal Additive Manufacturing technology and
to develop binder jetting-type machine for the rapid production of sand molds. The goal of TRAFAM
project is the development of innovative metal AM systems that will meet the world’s highest standards and
the development of AM technology for high value-added products for aerospace, medical, and transportation
industries etc. In this paper, the latest development status of the project, especially the development status of
the electron beam PBF type machines, the laser PBF type machine and the laser DED type machines, is
introduced. In addition, the numerical simulation software for metal AM based on multi-scale and multi-physics model is introduced.",,,,,,
"['Klippstein, Helge', 'Duchting, Anne', 'Reiher, Thomas', 'Hengsbach, Florian', 'Menge, Dennis', 'Schmid, Hans-Joachim']",2021-11-30T20:01:23Z,2021-11-30T20:01:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90529', 'http://dx.doi.org/10.26153/tsw/17448']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'aircraft bracket', 'development', 'production', 'post-processing']","Development, Production and Post-Processing of a Topology Optimized Aircraft Bracket",Conference paper,https://repositories.lib.utexas.edu//bitstreams/226c5ee3-5824-4b5c-975b-df87ad424180/download,University of Texas at Austin,"Structural parts for aviation have very high demands on the development and production
process. Therefore, the entire process must be considered in order to produce high-quality AM
metal parts. In this case study, a conventional part was selected to be optimized for AM. The
process presented includes component selection, design improvement with a novel approach for
topology optimization based on the AMendate algorithm as basis of MSC Apex Generative Design,
component production on a SLM 250 HL and post-processing including heat treatment and surface
smoothing. With the topology optimization a weight reduction of ~60 % could be realized, whereby
the stress distribution is more homogeneous. Furthermore, the challenges of support optimization
and post-processing have to be addressed, in order to produce competitive parts.",,,,,,
"['Skszek, Tim', 'Lowney, M.T.J.']",2019-09-23T15:42:41Z,2019-09-23T15:42:41Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75941', 'http://dx.doi.org/10.26153/tsw/3040']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Reconfiguration,Die Reconfiguration and Restoration Using Laser-Based Deposition 219,Conference paper,https://repositories.lib.utexas.edu//bitstreams/86895360-b89a-4b00-8dc2-cc2cd8e04a27/download,,"POM Company, Inc., located in Plymouth, Mich., has successfully commercialized the laser-based, free form fabrication process known as DMD,™ or Direct Metal Deposition. Since the company incorporated in 1998, POM has been directed towards the commercialization of the DMD process equipment, and the demonstration of value-added, cost-effective applications specific to the fabrication, repair and reconfiguration of plastic injection molds and die cast tooling. POM currently operates as a service bureau and original equipment manufacturer (OEM), providing engineering analysis, design and fabrication services, as well as the sale of DMD process equipment. An overview of the POM closed-loop, laser-based DMD process, available services and several case study applications are presented.",,,,,,
"['Rudraraju, Anirudh', 'Das, Suman']",2021-09-28T20:01:18Z,2021-09-28T20:01:18Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88168', 'http://dx.doi.org/10.26153/tsw/15109']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Large Area Maskless Photopolymerization', 'bitmaps', 'data compression', 'digital data processing', 'CAD models', 'STL files']",Digital Data Processing Strategies for Large Area Maskless Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/257508e4-933f-43c4-907d-5386095dfdc7/download,University of Texas at Austin,"Large Area Maskless Photopolymerization (LAMP) utilizes scanning spatial light
modulators that require layer slice data in the form of high‐resolution bitmaps. Three different
strategies have been implemented to fill this need. First, bitmaps were generated by direct slicing
of CAD models using Spatial Technology’s ACIS kernel. Second, bitmaps were generated from
STL files through ray‐tracing. Finally, an approach involving reconstruction of topological
information from STL files for efficient slicing and image generation is being developed. This
paper gives a brief description and implementation details of each of these strategies as well as
data compression techniques being pursued by the authors. This work is sponsored by DARPA
grant HR0011‐08‐1‐0075.",,,,,,
"['Aznarte, E.', 'Ayranci, C.', 'Qureshi, A.J.']",2021-11-02T17:53:56Z,2021-11-02T17:53:56Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89838,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'additive manufacturing', 'mechanical characterization', 'digital light processing', 'DLP', 'vat-photopolymerization', 'stereolithography']",Digital Light Processing (DLP): Anisotropic Tensile Considerations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f974ff89-8fad-4361-8ed1-610e2c22f4d3/download,University of Texas at Austin,"Digital light processing (DLP) 3D printing is an additive manufacturing (AM) process
used to produce layered parts via photopolymerization. Anisotropy is a common characteristic of
parts produced by DLP. Furthermore, printing conditions affect widely the resulting mechanical
properties. This paper shows the effect of three printing factors on the final mechanical
properties of specimens manufactured using DLP 3D printing. A series of ISO compliant tensile
test specimens were designed, printed and tested. The properties analyzed were the elastic
modulus, ultimate tensile strength, ultimate strain and printing time. Preliminary findings on
design guidelines for Vat Photopolymerization processes are presented in addition to the
economic effect of the studied parameters in terms of the total printing time.",,,,,,
"['Lipkowitz, Gabriel', 'Samuelsen, Tim', 'Hsiao, Kaiwen', 'Dulay, Maria T.', 'Coates, Ian', 'Pan, William', 'Shaqfeh, Eric S.G.', 'DeSimone, Joseph M.']",2023-02-17T14:40:08Z,2023-02-17T14:40:08Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117484', 'http://dx.doi.org/10.26153/tsw/44365']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['injection continuous liquid interface production (iCLIP)', 'continuous liquid  interface production (CLIP)', 'generative design', 'parametric design', 'algorithmic design', 'additive manufacturing', 'microfluidics']",Digital Microfluidic Design for Injection Continuous Liquid Interface Production of 3D Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0abe7c17-9739-486b-99bc-e01170caf46a/download,,"In additive manufacturing, it is imperative to increase print speeds, use higher 
viscosity resins, and print with multiple different resins simultaneously. To this end, we 
introduce a new UV-based photopolymerization 3D printing process exploiting a 
continuous liquid interface—the deadzone—mechanically fed with resin at elevated 
pressures through microfluidic channels dynamically created and integral to the 
growing part. Through such mass transport control, injection continuous liquid 
interface production, or iCLIP, accelerates printing speeds 5 to 10-fold over current 
methods such as continuous liquid interface production (CLIP), can utilize resins an 
order of magnitude more viscous than can CLIP, and can readily pattern a single 
heterogeneous object with different resins in all Cartesian coordinates. We 
characterize the process parameters governing iCLIP and demonstrate use-cases for 
rapidly printing carbon nanotube-filled composites, multi-material features with length 
scales spanning several orders of magnitude, and lattices with tuneable moduli and 
energy absorption.",,,,,,
"['Hadipoespito, George W.', 'Yang, Yong', 'Choi, Hongseok', 'Ning, Guoqing', 'Li, Xiaochun']",2019-11-08T15:27:10Z,2019-11-08T15:27:10Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78322', 'http://dx.doi.org/10.26153/tsw/5409']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Digital Micromirror,Digital Micromirror Device Based Microstereolithography for Micro Structures of Transparent Photopolymer and Nanocomposites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/450da3a8-9142-44a6-9067-0d5b4dfda444/download,,"This paper describes a Digital Micromirror Device (DMD) based ultraviolet (UV)
microstereolithography (µ-SL) system developed for rapid prototyping and manufacturing of
micro 3D structures. Characterization experiments show that the developed the DMD-based
imaging system irradiates an entire photopolymer layer at once, providing reasonable curing
speed and good resolution at a low cost. 2D and 3D micro parts were fabricated. High frequency
ultrasonic vibration (above 20 kHz) was experimented and verified that it can be used to
significantly decrease the leveling time of viscous photopolymer. Furthermore, micro parts were
also fabricated in nanocomposites, which were obtained by ultrasonic mixing of the transparent
photopolymer and nano-sized ceramic particles. High quality micro models fabricated by this
novel process could be used for micro scale investment casting, tooling, devices, and medical
applications.",,,,,,
"['Borstell, D.', 'Friedhofen, B.', 'Kunz, D.']",2024-03-27T03:48:35Z,2024-03-27T03:48:35Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124475', 'https://doi.org/10.26153/tsw/51083']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'digital modeling', 'cast iron', 'additive manufacturing', 'Cast Iron museum']",DIGITAL MODEL GENERATION STRATEGY FOR PRINTING MINIATURIZED REPLICA OF HISTORICAL CAST IRON OBJECTS – A USE CASE STUDY,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3be34b22-aa98-47c8-9afe-a987a8947f63/download,University of Texas at Austin,"The Cast Iron Museum at Sayn (Germany) hosts a wide range of historic cast iron
objects ranging from highly detailed fly-size figures to oversize eagles and church bells.
Replicating the historical cast iron, i.e. free formed objects, as miniaturized 3D prints for a new
exhibition requires scanning to create the digital model.
High quality of the digital model is a fundamental prerequisite for the production of the
miniaturized 3D print. The influence of software selection and settings during data preparation
from point cloud, mesh and finally solid is highlighted. Printing process selection is the final
step in achieving the required print quality.
A scanning and model generation strategy is developed and described using several
exemplary objects from the Sayn Museum. The final print quality resulting from the selected
scanning process is evaluated.",,,,,,
"['Hinter, J.', 'Basu, D.', 'Flynn, D.F.', 'Harris, R.A.', 'Kay, R.W.']",2021-11-09T16:27:58Z,2021-11-09T16:27:58Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90105', 'http://dx.doi.org/10.26153/tsw/17026']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['hybrid manufacturing', 'digitally-driven', 'ceramics', 'production', 'engineering']",A Digitally-Driven Hybrid Manufacturing Process for the Flexible Production of Engineering Ceramic Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9d4272c8-40ec-47f1-87dc-2ef08e9e2a12/download,University of Texas at Austin,"Ceramic materials are a versatile class of materials with numerous applications across a
range of industrial sectors. Predominant methods of manufacturing ceramic components use
template-driven methods, which hampers responsiveness and impose significant design
constraints. This has driven significant interest towards digitally-driven manufacturing
approaches, primarily, additive manufacturing. Additive manufacturing has demonstrated the
rapid production of bespoke and highly complex geometries and designs direct from digital
data without the need for component specific tooling. Yet, when used in isolation these
techniques are restricted by uncontrollable porosity, high shrinkages during firing plus a lack
of process-compatible materials. This paper presents the research and development of a new
hybrid manufacturing process chain for the agile production of engineering grade ceramics
components. The combination of high viscosity ceramic paste extrusion, sacrificial support
deposition and subtractive micro-machining has yielded complex monolithic ceramic
components with feature sizes of 100µm, part densities of ~99.7%, surface roughness down to
~1µm Ra and 3-point bend strength of 218MPa. Since a wide range of materials can be
formulated into visco-elastic pastes they can be readily deposited using this approach.",,,,,,
"['Smith, Matthew A.A.', 'Fry, Nicholas R.', 'Kay, Robert W.', 'Harris, Russell A.']",2021-11-09T15:56:27Z,2021-11-09T15:56:27Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90103', 'http://dx.doi.org/10.26153/tsw/17024']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['microsurface patterning', 'digitally-driven', 'in-process machine vision', 'topographical compensation', 'alignment capability', 'deposition', 'hybrid manufacturing']",Digitally-Driven Micro Surface Patterning by Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63945dc4-19a5-4689-830a-1be8d89a5a96/download,University of Texas at Austin,"Aerosol Jet printing is a versatile direct-write method allowing selective deposition and
alteration of surface chemistry on a variety of substrates, making it suitable for incorporation
in a range of hybrid manufacturing processes. The digitally controlled nature of the presented
hybrid manufacturing process enables rapid turnaround of designs, and improvements in
flexibility and complexity compared to established methods. The apparatus and instrumentation
that has been created at the University of Leeds enables specific processing conditions that
result in deposition of features with critical dimensions smaller than 20µm. In this study the
analysis of the effect of process variables on deposition geometries is presented. The features
were assessed by a combination of optical microscopy and white light interferometry. Using in-process machine vision, topographical compensation, and alignment capability the deposition
of material into micropatterned features in poly(dimethylsiloxane) (PDMS) was demonstrated.
High-value applications of this technology for surface functionalisation include electronics and
bio-engineering.",,,,,,
"['Kniepkamp, Michael', 'Fischer, Jakob', 'Abele, Eberhard']",2021-10-28T20:26:08Z,2021-10-28T20:26:08Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89691,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['dimensional accuracy', 'sub-millimeter parts', '316L', 'steel powders', 'micro selective laser melting']",Dimensional Accuracy of Small Parts Manufactured by Micro Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7177d2d1-da73-4a11-ad6a-d545e9da4ba1/download,University of Texas at Austin,"While selective laser melting of metallic parts is already widely used in today’s industry, problems in this
process still occur when using small parts with dimensions of less than 5 mm. Micro selective laser melting can
fill gaps with layer sizes of less than 10 microns and powders with particle sizes smaller than 5 microns. In this
paper the dimensional accuracy of parts with sub millimeter features using 316L steel powder is investigated.
Test specimens with different features like slopes, overhangs and sharp radii were built applying different scan
strategies. The parts were 3D scanned and compared to the CAD data to analyze their accuracy. Based on the
results, optimized scan strategies for the different features were developed to increase the parts’ overall
dimensional accuracy.",,,,,,
"['Mitchell, W.F.', 'Lang, D.C.', 'Merdes, T.A.', 'Reutzel, E.W.', 'Welsh, G.S.']",2021-11-01T20:59:22Z,2021-11-01T20:59:22Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89748,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['dimensional accuracy', 'Ti-6Al-4V', 'direct metal laser sintering', 'production quality']",Dimensional Accuracy of Titanium Direct Metal Laser Sintered Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13156315-df48-4564-a809-954795f23340/download,University of Texas at Austin,"To address concerns regarding quality of production parts created using the Additive
Manufacturing (AM) process, a study was conducted to quantify the dimensional accuracy of said
parts. Fourteen AM builds were manufactured in Ti-6Al-4V material across two EOS DMLS
machines (EOSINT M 280 and EOS M 290). In addition to studying the impact of machine-to-machine variability, other factors potentially impacting final dimensional accuracy were studied,
including: powder state (virgin or reused); post-processing steps (heat treatment and part removal
from substrate); location of part on substrate; and nominal part size. The results of the dimensional
analysis showed that the individual machine itself was the dominant factor impacting dimensional
accuracy. Also, a non-linear relationship between dimensional accuracy and nominal part size was
identified, which would require a more complex machine calibration technique to correct.",,,,,,
"['Terry, Shane', 'Fidan, Ismail', 'Tantawi, Khalid']",2021-11-18T00:27:19Z,2021-11-18T00:27:19Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90370', 'http://dx.doi.org/10.26153/tsw/17291']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['fused filament fabrication', 'metal powder filament', 'polylactic acid', 'metal 3D printing']",Dimensional Analysis of Metal Powder Infused Filament - Low Cost Metal 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e11710f-5c28-4b2b-9e53-c94b18047aab/download,University of Texas at Austin,"The process of Additive Manufacturing (AM) is the newest form of fabrication with the
primary method being layer-by-layer production. The most common form of this technology is
Fused Filament Fabrication (FFF), where material is deposited layer by layer to produce a highly
customized part. When compared to subtractive manufacturing the production of waste is greatly
reduced. This study presents some innovations on a new metal fabrication technique for FFF
printing. By printing a PolyLactic Acid (PLA) compliant metal powder composite filament, a part
can be made with approximately 90% metal composition and sintered. The sintering process
removes the PLA bonding leaving a 100% metal part fabricated on a low cost FFF printer. Overall,
this study reports the initial findings on dimensional changes in low cost metal 3D Printing process.",,,,,,
"['Murray, R.A.', 'Foy, G.', 'Clemon, L.']",2021-11-18T17:37:19Z,2021-11-18T17:37:19Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90441', 'http://dx.doi.org/10.26153/tsw/17362']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['cold spray', 'scanning', 'part inspection', 'metal additive', 'high-velocity particle spray']",Dimensional Comparison of a Cold Spray Additive Manufacturing Simulation Tool,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2f2b0bd-2b97-48ea-9f33-73b6e3f0e1e6/download,University of Texas at Austin,"High-velocity particle spray greatly increases metal additive manufacturing deposition speed over
other commercial methods. Accurate prediction and measurement of this process will improve process
control. A LightSPEE3D machine fabricated symmetric copper components. On-board software
predicts the build geometry (.stl) given the input geometry and the build settings. Assessment of
prediction accuracy is needed to enable rapid part design and print setting optimization. White-light
3D-scanning and high-fidelity optical microscopy scans are compared to the simulation and intended
20mm cubes using hausdorf distance:
1. Control-repeated scans: 0.38±0.48mm, max:2.25mm
2. Intended-original vs. scans: 1.42±1.58mm, max:6.72mm
3. Software-predicted vs. scans: 0.44±0.66mm, max:3.97mm
Discrepancies up to 6.72mm and asymmetric fabrication artifacts were identified. The reduction in the
hausdorf distance for simulation vs intended-original, and larger distance of the simulation compared
to control, indicate the simulation tool may enable rapid optimization given over/under spray
quantification. Recommendations for reducing asymmetric fabrication artifacts and over/underspray
are provided.",,,,,,
"['Winmill, David L.', 'Hoopes, Daniel M.', 'Jayanthi, Suresh S.']",2019-02-22T17:32:32Z,2019-02-22T17:32:32Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73463', 'http://dx.doi.org/10.26153/tsw/613']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping technologies', 'stereolithography']",Dimensional Issues in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4d64ba71-9666-4471-85c6-b1ec0a6efa38/download,,"New stereolithography photopolymers have recently been introduced that provide a wider
range of functional properties similar to those of high-density polyethylene. One of the
important criteria for these materials is the dimensional accuracy and stability in end-use
applications as mold masters or the actual functional parts. This work investigates the
dimensional stability of one of these new materials with varying amounts of exposure during
build. The effect of aging on the part dimensions is reported. The result of environmental
humidity extremes at ambient temperature on part dimensions is investigated and compared for
parts made from two different families of stereolithography resins, namely DuPont Somos® 7100
and Somos® 8100.",,,,,,
"['Wang, Wanlong', 'Conley, James G', 'W Stoll, Henry']",2019-02-25T17:42:28Z,2019-02-25T17:42:28Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73476', 'http://dx.doi.org/10.26153/tsw/626']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD']",Dimensional Variability Analysis ln Post-Processing Of Rapid Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/133ba5a1-0725-4965-92ae-acc4a3263c0c/download,,"Rapid tooling for sand casting can be made by creating pattern with elements made by solid
freeform fabrication (SFF) devices. Using this approach, post-processing and hand finishing
remain as necessary steps to improve the surface finish quality of the pattern. For rapid·.tooling
using laminated object manufacturing (LOM) models, post-processing includes decubing,
sanding and sealing followed by integration with a match plate and/or conventional cope & drag
pattern elements. Since the critical finishing operations are intensively manual, it is difficult to
estimate the dimensional capability of rapid tooling by.LaM process. The Objective of this paper
is to use statistics to evaluate dimensional variability associated with postprocessing using the
accepted industry best practice.",,,,,,
"['Ruan, Jianzhong', 'Tang, Lie', 'Sparks, Todd E.', 'Landers, Robert G.', 'Liou, Frank']",2020-03-11T15:43:16Z,2020-03-11T15:43:16Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80257', 'http://dx.doi.org/10.26153/tsw/7276']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Direct 3D Layer Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8a3c7b63-8cc0-46e6-a3a0-91ee19b5a656/download,,,,,,,,
"['Frank, Matthew C.', 'Harrysson, Ola', 'Wysk, Richard A.', 'Chen, Niechen', 'Srinivasan, Harshad', 'Hou, Guangyu', 'Keough, Carter']",2021-11-04T15:51:00Z,2021-11-04T15:51:00Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89989', 'http://dx.doi.org/10.26153/tsw/16910']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['direct additive substrate hybrid manufactured', 'DASH', 'geometric specification', 'geometric accuracy', 'out of envelope']",Direct Additive Subtractive Hybrid Manufacturing (DASH) – An Out of Envelope Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03287dc0-dcb9-46fe-a9e5-73a4c2cd8915/download,University of Texas at Austin,"This work addresses a critical issue affecting the adoption of metal additive manufacturing (AM)
methodologies; creating a system that can produce a mechanical product to final geometric
specification. To date, almost all functional metal AM parts have required secondary processing
that in many cases can more than double the cost of the final part. A Direct Additive and
Subtractive Hybrid (DASH) manufacturing system using both additive and then subtractive
processing has been developed so that mechanical parts can be “digitally manufactured” to meet
the final required geometric accuracy. The approach includes the development of a software
system to link additive and subtractive manufacturing, using extensions to the AMF format, to
maintain product design features along with their tolerance specifications. It also introduces the
idea of sacrificial fixtures that are automatically designed into the parts to allow subsequent
fixturing in the CNC mill. Once in the milling machine, a part localization system identifies the
part and its location, along with capturing the geometry of any remaining AM support material left
on the part. Finally, all CNC code is automatically generated and the finishing process can be
executed in a lights-out operation. This work provides a drastic reduction in post processing time
and cost. It further enables expansion of metal AM and uniquely addresses the challenge of out-of-envelope hybrid manufactured parts.",,,,,,
"Frazier, William E.",2021-09-30T20:16:32Z,2021-09-30T20:16:32Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88294', 'http://dx.doi.org/10.26153/tsw/15235']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Navy Workshop', 'direct digital manufacturing', 'technical challenges', 'research & development', 'R&D', 'R&D roadmap', 'innovative structural design', 'maintenance and repair', 'qualification and certification methodology', 'DDM science & technology']",Direct Digital Manufacturing of Metallic Components: Vision and Roadmap,Conference paper,https://repositories.lib.utexas.edu//bitstreams/457c2d4d-90d2-410c-88f6-5cc3bb7e23d8/download,University of Texas at Austin,,,text,,,,
"['Chi, Xiaopeng', 'Yang, Hongyi', 'Shoufeng, Yang', 'Evans, Julian R. G.']",2020-02-28T20:40:17Z,2020-02-28T20:40:17Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80119', 'http://dx.doi.org/10.26153/tsw/7140']",eng,2006 International Solid Freeform Fabrication Symposium,Open,scaffolds,Direct Extrusion Freeforming of Ceramic Pastes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3efc3bb4-fba5-4a42-be9b-fb73429a4f20/download,,"Microextrusion freeforming of ceramic lattices from high solids ceramic pastes provides
multi-scale hierarchical void structures with the advantages of low shrinkage stress and high
sintered density. Alumina lattices were directly fabricated using 80-500 Pm diameter filaments.
We report here on the implementation of design and fabrication of these scaffolds for band gap
materials and micro fluidic devices.",,,,,,
"['Harrysson, Ola L.A.', 'Cormier, Denis R.', 'Marcellin-Little, Denis J.', 'Jajal, K.R.']",2019-11-21T18:00:41Z,2019-11-21T18:00:41Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78548', 'http://dx.doi.org/10.26153/tsw/5604']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Direct Fabrication,Direct Fabrication of Metal Orthopedic Implants Using Electron Beam Melting Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85fb7e27-cb2b-42e4-88f4-dc4db0b09195/download,,"Metal orthopedic implants have been used for many decades with great success.
Replacement joints and plates for bone fractures are usually made from titanium, cobaltchromium or stainless steel. Through recent advancements in biomodeling, custom orthopedic
implants can be designed. However, fabrication of these custom implants can be prohibitively
expensive with traditional processes. With the introduction of Electron Beam Melting (EBM),
direct fabrication of fully dense metal components is possible. In this paper, the development of
titanium for the EBM-process will be discussed, and direct fabrication of custom designed
orthopedic implants made out of steel and titanium will be demonstrated.",,,,,,
"['Klosterman, Donald', 'Chartoff, Richard', 'Agarwala, Mukesh', 'Fiscus, Ira', 'Murphy, John', 'Cullen, Sean', 'Yeazell, Mark']",2019-03-17T14:04:40Z,2019-03-17T14:04:40Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73699', 'http://dx.doi.org/10.26153/tsw/841']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'PMC']",Direct Fabrication of Polymer Composite Structures with Curved LOM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b3965f93-7cdf-46b9-bdda-20dda9fda7d6/download,,"This report describes the application of Curved LOM to the direct fabrication of polymer matrix
composites (PMCs). The overall methodology of directly fabricating PMC parts involved the use of the
Curved LOM machine to lay-up and shape ""green"" composite laminates from prepreg feedstocks,
followed by vacuum bag / oven cure and consolidation. The conventional Curved LOM laminator was
replaced with a vacuum thermoforming apparatus to better accommodate the bonding of commercially
available prepregs. The study also demonstrated that it is possible to interface a general composite design
sofiware package with the Curved LOM machine via the curved slice file (.CSF) format. Taken together,
these two improvements allow for improved flexibility in manufacturing PMC components, from both a
material handling and a design point-of-view. A simple C-shaped panel was fabricated and tested to
demonstrate the overall feasibility of the process for PMCs. A glass fiber 1 epoxy prepreg obtained from a
commercial supplier was used as a model material system. It was found that the cumulative accuracy of
the overall process was good, and the mechanical properties of the laminates were acceptable for nonstructural applications for which the material is normally used.",,,,,,
"['Maxwell, J. L.', 'Pegna, J.', 'Messia, D.', 'DeAngelis, D.']",2018-11-14T16:46:02Z,2018-11-14T16:46:02Z,1996,Mechanical Engineering,doi:10.15781/T28G8G34G,http://hdl.handle.net/2152/70238,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['Solid Area Laser Deposition', 'Chemical Vapor Deposition', 'Graphite']",Direct Feedback Control of Gas-Phase Laser-Induced Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4cb30558-e50a-466b-98d7-0509a2fae945/download,,"Three-dimensional laser Chemical vapor deposition (3D-LCVD) or SALD, was used to
prototype metallic and ceramic microstructures. Iron, nickel, and steel metal forms were grown
from organic and halogen based precursors. Through the simultaneous use of multiple precursors,
specific nickel-iron based alloys were produced. By observing the emission spectra during
growth, a measure ofthe volumetric growth rate, was obtained. Direct, PID control ofthe process
was then possible using the growth rate measurement as real-time feedback. Calibrated infrared
photographs of evolving microstructures were taken at various wavelengths, giving a measure of
the temperature gradient over the growth zone. While radiation contributes to heat losses at high
temperatures, enhanced convection is the dominant heat transfer mechanism due to the small
dimensions of the heated area. Enhanced growth rates, induced by convective flow, were also
observed. The heat and mass transfer coefficients were determinedfor various processing conditions,
and compare well with experimental data. Axi-symmetric rods may also be grown in both
the kinetic and transport-limited regimes, and a systematic study of the precursor pressure and
deposit temperature during growth yielded distinct growth regimes, influn, ced by the interplay of
heat losses and diffusive transport.",,,,,,
"['Cohen, D. L.', 'Malone, E.', 'Lipson, H.', 'Bonassar, L. J.']",2020-02-17T15:27:31Z,2020-02-17T15:27:31Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/80010', 'http://dx.doi.org/10.26153/tsw/7035']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Alginate gels,Direct Freeform Fabrication of Spatially Heterogeneous Living Cell-Impregnated Implants,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4b96184-0e7e-4a6d-aa06-eefa340e1a53/download,,"The objectives of this work are the development of the processes, materials, and tooling to
directly “3-D print” living, pre-seeded, patient-specific implants of spatially heterogeneous
compositions. The research presented herein attempts to overcome some of the challenges to
scaffolding, such as the difficulty of producing spatially heterogeneous implants that require
varied seeding densities and/or cell-type distributions. In the proposed approach, living implants
are fabricated by the layer-wise deposition of pre-cell-seeded alginate hydrogel. Although
alginate hydrogels have been previously used to mold living implants, the properties of the
alginate formulations used for molding were not suitable for 3-D printing. In addition to changing
the formulation to make the alginate hydrogels “printable,” we developed a robotic hydrogel
deposition system and supporting CAD software to deposit the gel in arbitrary geometries. We
demonstrated this technology’s capabilities by printing alginate gel implants of multiple materials
with various spatial heterogeneities, including, implants with completely embedded material
clusters. The process was determined to be both viable (94±5% n=15) and sterile (less than one
bacterium per 0.9 µL after 8 days of incubation). Additionally, we demonstrated the printing of a
meniscus cartilage-shaped gel generated directly from a CT Scan. The proposed approach may
hold advantages over other tissue printing efforts [5,9]. This technology has the potential to
overcome challenges to scaffolding and could enable the efficient fabrication of spatially
heterogeneous, patient-specific, living implants.",,,,,,
"Guduri, Sashidhar",2018-05-03T19:51:07Z,2018-05-03T19:51:07Z,1993,Mechanical Engineering,doi:10.15781/T2N010B19,http://hdl.handle.net/2152/65071,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'SFF', 'Three Dimensional Printing', 'computer models']",Direct Generation of Contour Files from Constructive Solid Geometry Representations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0a1b45a-417b-4679-8c27-4bb2bcfeee35/download,,"Geometry processing for layer-based Solid Freeform Fabrication consists of at least two
steps: slicing the geometry to obtain the part contours for each layer, and scan-converting the
layers for laser scanning (or other device-dependent in-layer processing). This paper discusses
the generation of contour files directly from Constructive Solid Geometry (CSG) representations
for the Selective Laser Sintering process. Previous work at The University of Texas focused on
slicing CSG representations composed of quadric primitives. This paper extends previous work
at UT to include the torus, a fourth degree surface, as one of the CSG primitives. Slicing a torus
results in a fourth degree equation in two variables, which represents a curve in two-dimensional
real space. For. some special cases, this fourth degree equation may be sub-divided into two
second degree equations. For the cases where the fourth degree equation cannot be sub-divided,
a method is presented to approximate the fourth degree curve with second degree curve
segments.",,,,,,
"['Nelson, Christian', 'Kepler, Jason', 'Booth, Rick', 'Conner, Phillip']",2019-02-26T16:33:34Z,2019-02-26T16:33:34Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73483', 'http://dx.doi.org/10.26153/tsw/633']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Rapid Tooling', 'DTM']",Direct Injection Molding Tooling Inserts from the SLS Process with Copper Polyamide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a25c9595-6d2f-4f27-b0a2-a49e033735ab/download,,"The ""RapidTool"" Short Run (SR) Tooling Process using the Copper Polyamide
material provides a route to mold inserts for injection molding made directly in
the Selective Laser Sintering machine. The STL files for the mold inserts are
shelled and conformal cooling lines and ejector pin guides are added before SLS
processing. Sintering of the material in the SLS machine provides quick
metal/plastic tooling with good thermal conductivity. Final preparation of the
tooling inserts includes sealing the surface with epoxy, final finishing using
sandpaper, and backing up the shells with a metal alloy. The Copper Polyamide
SR Tooling inserts are used to mold several hundred parts with common plastics
with injection cycle times similar to conventional molding cycle times.",,,,,,
"['Yan, Lei', 'Chen, Xueyang', 'Li, Wei', 'Liou, Frank', 'Newkirk, Joe']",2021-10-20T21:48:16Z,2021-10-20T21:48:16Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89370,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['direct laser deposition', 'powder blends', 'microstructure', 'composition distribution']",Direct Laser Deposition of Ti-6Al-4V from Elemental Powder Blends,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2558bedc-301b-4dfb-b385-e941075efb13/download,University of Texas at Austin,"A thin-wall structure composed of Ti-6Al-4V has been deposited using direct laser
deposition (DLD) from blended Ti, Al, and V elemental powders. The microstructure and
composition distribution along the build height direction were intensively investigated using
optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy
(SEM/EDS), and Vickers hardness testing. The microstructures of the as-deposited Ti-Al-V
were studied using EDS to determine appropriate weight percentage for Al and V in the blended
powders before mixing. The effects of laser power and laser transverse speed on the microstructure
were investigated and optimized laser processing parameters were concluded.",,,,,,
"['Das, Suman', 'P. Fuesting, Timothy', 'Danyo, Gregory', 'Brown, Lawrence E.', 'Beaman, Joseph J.', 'Bourell, David L.', 'Sargent, Kathleen']",2019-02-18T17:30:09Z,2019-02-18T17:30:09Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73391', 'http://dx.doi.org/10.26153/tsw/543']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['affordability', 'technique']",Direct Laser Fabrication of a Gas Turbine Engine Component - Microstructure and Properties - Part I,Conference paper,https://repositories.lib.utexas.edu//bitstreams/af208a6d-65c9-4b51-b019-da5158482253/download,,"This paper presents the development of a new technique for the production of abrasive
turbine blade tips by direct laser processing. This superalloy cermet component is an integral part
of the low pressure turbine sealing system in a demonstrator engine. Direct laser fabrication of
this component fiom a bed a loose powder results in significant cost savings and improved
performance over the currently employed production technique. The technology has been
demonstrated by fabricating a prototype lot of 100 blade tips, which will be subjected to an engine
test. This is the first instance of a direct fabrication method applied to the production of functional
engine hardware. This research was funded by the United States Air Force contract F33615-94-
C-2424 titled ""Affordable Turbine Blade Tips"".",,,,,,
"['Wohlert, Martin', 'Das, Suman', 'Beaman, Joseph J.', 'Bourell, David L.']",2019-03-12T19:58:24Z,2019-03-12T19:58:24Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73607', 'http://dx.doi.org/10.26153/tsw/749']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'Alloy 625']",Direct Laser Fabrication of High Performance Metal Components Via SLS/HIP,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba0202c1-c105-46ee-bfcf-eab883186930/download,,"Recent research in the area of direct freeform fabrication of components via selective laser
sintering/hot isostatic pressing (SLS/HIP) has focused on the processing of Alloy 625. Alloy 625
is a nickel-based superalloy which provides high temperature strength and corrosion resistance.
Alloy 625 test specimens were successfully SLS processed with an integral gas impenneable skin
or ""can"". These samples were subsequently HIPed to high density (>99.5%). Characterization of
the test specimens indicated that microstructures similar to conventionally processed P/M
materials are achieved in the HIP consolidated ""core"" region ofthe parts, while structures similar
to those found in cast materials are present in the SLS processed ""can"" regions. Mechanical
analysis of Alloy 625 SLS/HIP parts and production of complex structures will commence
shortly.",,,,,,
"['Klocke, F.', 'McClung, A.', 'Ader, C.']",2020-02-13T19:08:25Z,2020-02-13T19:08:25Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79961', 'http://dx.doi.org/10.26153/tsw/6986']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Direct Laser Sintering of Borosilicate Glass,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3234094a-3774-46b1-b8ef-f34b54ae6b2a/download,,"Despite the advantages that selective laser sintering (SLS) offers in terms of material
availability, many materials have yet to be explored for feasibility and even fewer are
available on a commercial basis. This paper presents initial investigations for one such
material, borosilicate glass, which could be of particular interest to filter manufacturers
because it presents an attractive alternative to the conventional, time-consuming way of
producing filters of various porosity classes. Process results are presented including a
determination of the optimal parameter window and the effect of processing parameters on the
density and surface quality. The effects of thermal post-processing and the inclusion of an
additive are also discussed.",,,,,,
"['Klocke, F.', 'Ader, Christoph']",2019-11-21T18:02:10Z,2019-11-21T18:02:10Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78549', 'http://dx.doi.org/10.26153/tsw/5605']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Ceramics,Direct Laser Sintering of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a52bcc83-70d9-4824-ac7c-4e30f08b80bd/download,,"For more than one decade layer manufacturing technologies assist the development of new
products. Due to a layer-wise build-up of a three-dimensional geometry, nearly every
complex design is producible in a short period of time. Selective Laser Sintering is a powderbased technique to produce plastic prototypes (Rapid Prototyping) or metal mould inserts
(Rapid Tooling). The laser sintering of ceramic powder is not yet commercialized but
applications could be both Rapid Prototyping and Rapid Tooling. The former involves the
laser sintering of investment casting shells and cores to cast metal prototypes and the latter the
laser sintering of ceramic master patterns for metal spray forming of steel mould inserts. The
advantage compared to actual processes are a faster availability of the final product. To
facilitate these applications, special ceramic powders as well as new process parameter
combinations were investigated. This paper will present achieved results within the abovedescribed applications.",,,,,,
"['Carter, William T.', 'Jones, Marshall G.']",2018-05-03T16:44:29Z,2018-05-03T16:44:29Z,1993,Mechanical Engineering,doi:10.15781/T2513VD0T,http://hdl.handle.net/2152/65036,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'laser beam', 'rapid prototyping', 'stereolithography']",Direct Laser Sintering of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dea2ff2e-bf4f-4ee5-acc1-f5ea3905b4d2/download,,"The use of a directed laser bealn source to selectively sinter multiple layers of
binderless metal powder for the purposes of rapid prototyping is described. The
work in this paper is restricted to -325 mesh iron powder, which was sintered
using a C\V 50 W Nd:YAG laser to approximately 3.5% density. A subsequent
post-treatlnent was perfornled to achieve a fully dense saulple. It is envisioned
that such a system can be used to manufacture functional metallic prototypes
directly from CAD without part-specific tooling.",,,,,,
"['Wilkening, C.', 'Sindel, M.', 'Pintat, T.', 'Greul, M.', 'Nyrhila, O.']",2018-09-26T20:36:38Z,2018-09-26T20:36:38Z,1994,Mechanical Engineering,doi:10.15781/T28P5VV59,http://hdl.handle.net/2152/68595,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['direct laser sintering', 'rapid prototyping', 'selective-laser sintering']",Direct Laser Sintering of Metals and Metal Melt Infiltration for Near Net Shape Fabrication of Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3421af5-4ba4-4997-a205-7bfbca3bbafb/download,,"Direct laser sintering of metal powders is a great challenge for Rapid Prototyping
(RP) because of the high potential of application, for example prototype tooling for
polymer extrusion.
Recent development in laser sintering ofmetal powders use polymer or low melting
alloys as a binder phase. Postsintering to strengthen the component produces
shrinkage ofthe part, hence the near net shape capability is limited.
The combination of direct laser sintering and infiltration with metal melts allows the
production ofstrong near net shaped components without shrinkage.
A composite metal powder consisting ofNi, Cu, Sn and P was successfully sintered
in a Selective-Laser Sintering unit in ambient atmosphere at room temperature. The
influence oflaser intensity on microstructure and sintering behaviour is discussed.
Infiltration experiments were done with partially sintered samples. Full density
could be achieved without shrinkage. Mechanical properties and microstructural
development will be discussed.",,,,,,
"['Klocke, Fritz', 'Wirtz, H', 'Meiners, W.']",2018-11-09T16:29:29Z,2018-11-09T16:29:29Z,1996,Mechanical Engineering,doi:10.15781/T2XS5K282,http://hdl.handle.net/2152/69931,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'polymer binder', 'metal build up']",Direct Manufacturing of Metal Prototypes and Prototype Tools,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e8ab4a32-dbdc-4e20-ba1b-b5be5ba96a1d/download,,"Due to the limited mechanical characteristics of the materials which can currently be
processed using industrially available Rapid Prototyping machines, a lot of research is focused on
the development of techniques which allow a direct manufacturing of metallic parts. These
include Selective Laser Sintering and Controlled Metal Build Up. Both methods produce the
workpiece not by removal of material but by a layerwise deposition and local melting or sintering
of a powder material without part-specific tooling.
Controlled Metal Build Up is a new Rapid Prototyping technique similar to Fused
Deposition Modeling combining laser generating/welding with conventional 2Y2 dimensional
milling. Due to the excellent surface quality and high dimensional and form accuracy achievable
with Controlled Metal Build Up, this technology offers an interesting alternative to the
conventional time consuming processes for the manufacture of prototype tools required for
limited production runs.
With respect to Selective Laser Sintering, a test facility was developed for experimental
investigations into the direct sintering of low and high melting metallic powders without the use
of a polymer binder as well as ceramic powders. Great potential is expected from Selective Laser
Sintering concerning the prototyping of molds and dies.
This paper will discuss current developments for these two techniques as well as point out
possible applications and future developments.",,,,,,
"['Ramos-Grez, Jorge', 'Sanz-Guerrero, Jorge', 'Larraín, Tomás', 'Ramírez, Andrés']",2020-02-28T15:58:54Z,2020-02-28T15:58:54Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80113', 'http://dx.doi.org/10.26153/tsw/7134']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Direct Metal Laser Fabrication,Direct Metal Laser Fabrication of Cu Slabs from Powder Precursor: Surface Depth of Melt and Furnace Temperature Issues,Conference paper,https://repositories.lib.utexas.edu//bitstreams/036e1e0a-e03f-4a3e-81f6-b09be34de1a0/download,,"A DMLF processing unit based on a raster-scanned 80 W CO2 laser beam has been
developed to process single layers of metallic powder precursor. The process chamber
provides atmosphere control (high vacuum and inert gas refill) besides temperature
elevation up to 700 o
C. In this work, copper powder precursor is confined inside a
refractory steel mask surrounded by an aluminum oxide jacket that acts as insulator. The
powder layers can have thicknesses of 0,5 and 1 mm. An infrared pyrometer measures
in real time the temperature at one location in the surface of the powder bed. Scan
speed, scan step, and furnace temperature have been varied to find combinations of such
parameters that render surface melting and maximum densification. Partially melted
samples were produced and their mass density was measured. Micro-hardness and
surface roughness were also measured along the resolidified surface, the first rendering
an average of 80,6 HV compared to the 90-105 HV of oxygen free copper, while the
second resulting in an 8 μm Ra value. Maximum melt of depth achieved is ~0,15 mm
followed by a sintered layer.",,,,,,
"['Carter, William T.', 'Graham, Michael E.', 'Hayden, Christopher', 'Jeong, Younkoo', 'Mamrak, Justin', 'McCarthy, Brian', 'Monaghan, William', 'Nieters, Edward J.', 'Ostroverkhov, Victor', 'Roychowdhhury, Subhrajit', 'Schmitz, Andrea', 'Tucker, Michael R.']",2021-11-18T19:00:16Z,2021-11-18T19:00:16Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90468', 'http://dx.doi.org/10.26153/tsw/17389']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['direct metal laser melting', 'DMLM', 'rotating powder bed', 'aircraft engine industry']",A Direct Metal Laser Melting System Using a Continuously Rotating Powder Bed,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ad054fe6-253a-4dbc-bff1-5aec61cd6001/download,University of Texas at Austin,"The aircraft engine industry manufactures many metal parts of large diameter, but small
cross-sectional area. Designers of these parts require increasingly complex geometries for
improved aerodynamic efficiency and cooling. The combination of large diameter and complex
geometric features inspired the development of a new Direct Metal Laser Melting (DMLM)
architecture with a rotating powder bed. The system coordinates the rotational motion of a powder
bed with an ascending laser scanner and recoater to build in a helical fashion. A single-point
powder feeder delivers metal powder near the inner radius of an annular build volume, and the
recoater spreads the powder to the outer radius in a “snow plow” fashion. Because the recoater and
laser scanner are installed at different angular positions, they operate independently and
simultaneously. A prototype system was built to demonstrate this concept for an aircraft engine
combustor liner (600-mm dia. x 150-mm ht.) and showed continuous laser utilization exceeding
97%.",,,,,,
"['Morgan, Rhys', 'Papworth, Adam', 'Sutcliffe, Chris', 'Fox, Pete', ""O'Neill, Bill""]",2019-10-18T15:03:36Z,2019-10-18T15:03:36Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76231', 'http://dx.doi.org/10.26153/tsw/3320']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Primitives,Direct Metal Laser Re-Melting of 316L Stainless Steel Powder Part 2: Analysis of Cubic Primitives,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47a416a6-d771-4510-8618-6894e204234f/download,,"Direct Metal Laser Re-Melting is a process variant of Selective Laser Sintering, whereby 316L
stainless steel powder fractions are melted by a high power Nd:YAG laser. Layers are built up as
a series of single lines to produce thin walled structures in the range »0.3-1.0mm thick. The
structures exhibit a periodic, angular roughness to the wall surfaces. The samples also display a
wave-like pattern on their upper surfaces. Further investigations reveal the angled ‘wave’ pattern
exists on a macroscopic level in the microstructure. The pattern is fully formed by the third or
fourth layer. Fern-like grain structures follow the orientation of the surface roughness and exist
across many layers. This is believed to be the effect of grain orientation within the samples. The
microstructure reveals long, needle, cell structures. The uni-axial needles grow epitaxially from
previous layers. The samples have been shown to exhibit very little or no thermally induced
residual stresses.
Introduction",,,,,,
"['Das, Suman', 'Wohlert, Martin', 'Beaman, Joseph J.', 'Bourell, David L.']",2018-11-28T19:45:04Z,2018-11-28T19:45:04Z,1997,Mechanical Engineering,doi:10.15781/T2PZ52629,http://hdl.handle.net/2152/70328,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SLS']",Direct Selective Laser Sintering and Containerless Hot Isostatic Pressing for High Performance Metal Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4ea0d668-9945-4e4c-bb4b-ce385409e227/download,,"A novel net shape manufacturing method known as SLSIHIP that
combines the strengths ofselective laser sintering (SLS) and hot isostatic pressing
(HIP) is presented. Direct selective laser sintering is a rapid manufacturing
technique that can produce high density metal components of complex geometry
with an integral, gas impermeable skin. These components can then be directly
post-processed to full density by containerless HIP. The advantages of in-situ
HIP encapsulation include elimination of a secondary container material and
associated container-powder interaction, reduced pre-processing time, a short HIP
cycle and reduction in post-processing steps compared to HIP of canned parts.
Results of research conducted on Inconel 625 superalloy, Ti-6AI-4V and Monel
are presented. This research is funded by DARPAlONR contract N00014-95-C0139
titled ""Low Cost Metal Processing Using SLSIHIP"".",,,,,,
"['Zong, G.', 'Wu, Y.', 'Tran, N.', 'Lee, I.', 'Bourell, D.L.', 'Beaman, J.J.', 'Marcus, H.L.']",2018-04-19T16:15:36Z,2018-04-19T16:15:36Z,1992,Mechanical Engineering,doi:10.15781/T2V980830,http://hdl.handle.net/2152/64379,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Department of Mechanical Engineering', 'SLS']",Direct Selective Laser Sintering of High Temperature Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/161858a9-ba25-4bd3-af3b-43224a390ef0/download,,"Selective Laser Sintering (SLS) involving a coexisting liquid and particulate solid during
the SLS processing can be used to produce freeform parts directly with high temperature
materials. Factors such as scanning laser power density, residence time, scan line spacing, the
interfacial energies between the liquid and solid phases, powder bed biasing temperature, and
sintering atmosphere greatly affect the microstructure evolution in the SLS process. Direct
SLS of high melting temperature mixed powder materials was demonstrated using a 1.1 kW
C02 laser SLS system. The relationship between the microstructures and the process
parameters will be described.",,,,,,
"['Meyers, Sebastian', 'Kruth, Jean-Pierre', 'Vleugels, Jef']",2021-10-21T22:00:17Z,2021-10-21T22:00:17Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89454,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['direct selective laser sintering', 'reaction bonded silicon carbide', 'silicon carbide']",Direct Selective Laser Sintering of Reaction Bonded Silicon Carbide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6267a2a0-b6c3-4128-912a-db5f182f5afa/download,University of Texas at Austin,"Three-dimensional reaction bonded silicon carbide (SiSiC or RBSC) parts have been
produced by direct selective laser sintering (SLS). Unlike previously investigated processing
routes, which make use of a sacrificial polymer binder to form green parts, the parts in this work
are built by scanning subsequent layers composed of a mixture of silicon and silicon carbide
powders. A fibre laser is used to selectively melt the silicon under an inert argon atmosphere,
resulting in porous preforms of sufficient strength for further handling and processing. After
impregnation with a graphite suspension and infiltration with liquid Si at 1450°C, highly dense
reaction bonded silicon carbide parts are obtained.",,,,,,
"['Klocke, Fritz', 'Wagner, Christian']",2019-10-23T14:33:31Z,2019-10-23T14:33:31Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76703', 'http://dx.doi.org/10.26153/tsw/3792']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Superalloys,Direct Selective Laser Sintering of Superalloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0f44ab7-c36b-4e15-a38d-53c46847611a/download,,"The advantages of powder metallurgy lie within the large degree of freedom for material design and
thus is especially used in the production of high performance parts. Layer manufacturing is an
appropriate method to produce complex parts rapidly. Direct Selective Laser Sintering (SLS) presents a
technology which combines both benefits. Therefore many efforts are done today to qualify new
materials for SLS [DAS 98, MEI 99, OVE 01, WOL 00]. Particulary materials, which are hard to cut, to
cast or to shape in any else matter, are of interest.
In the presented paper investigation results on Selective Laser Sintering of metals are shown on the
basis of the nickel base alloy INCONEL™ 718. First, a process model has been created to discribe the
mechanisms of SLS of metals. On the base of the model, process simulations and experimental
investigations have been performed. In some cases, affiliating a heat treatment after the laser sintering
step is favorably to improve the metallic structure and thus has also been tested. Finally, the
metallograhic structures and mechanical properties were analysed.",,,,,,
"['Hauser, C.', 'Childs, T.H.C.', 'Taylor, C.M.', 'Badrossamay, M.', 'Akhtar, S.', 'Wright, C.S.', 'Youseffi, M.', 'Kie, J.', 'Fox, P.', 'O’Neill, W.']",2019-11-21T18:48:45Z,2019-11-21T18:48:45Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78569', 'http://dx.doi.org/10.26153/tsw/5625']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Direct Selective,Direct Selective Laser Sintering of Tool Steel Powders to High Density: Part A - Effects of Laser Beam Width and Scan Strategy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ebb60ec0-1457-4c16-b383-a0bddabd801a/download,,"This paper describes progress on the Direct Selective Laser Sintering of M2 and H13 tool
steel powders, comparing this with previous and further observations on stainless steel powders.
The distinguishing feature is the melting of single tracks and layers in deep powder beds. The
paper focuses on changing characteristics of the melt pool (mass, volume, aspect ratio, stability)
and laser-powder interactivity as the laser beam width, power and scan speed change. It also
compares the melt pool of neighbouring tracks during single layer construction. Simulations
from a computer model to predict melt pool shape and dimension show reasonable agreement
with experimental results at low scan speeds (0.5mm/s). But unexpected increases in melt depth
above 1.0mm/s have been observed, suggesting higher values and more variability in laser
absorptivity than expected, even approaching 1.0 for the CO2 laser radiation used in this work.",,,,,,
"['Akhtar, S.', 'Wright, C.S.', 'Youseffi, M.', 'Hauser, C.', 'Childs, T.H.C.', 'Taylor, C.M.', 'Baddrossamay, M.', 'Xie, J.', 'Fox, P.', 'O’Neill, W.']",2019-11-21T18:51:29Z,2019-11-21T18:51:29Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78570', 'http://dx.doi.org/10.26153/tsw/5626']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Direct Selective,Direct Selective Laser Sintering of Tool Steel Powders to High Density: Part B -The Effect on Microstructural Evolution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e8ae3f3-cee5-45f1-ab8a-cc77f1ba5d88/download,,"This paper describes recent progress on the Direct Selective Laser Sintering of M2 [Fe6W-5Mo-4Cr-2V-0.8C] high speed steel (HSS) and H13 [Fe-5Cr-1V-1Si-1.5Mo-0.4C] tool steel
powders. Part B will focus on the microstructural evolution of laser scanned powder beds. It has
been found that H13 powders are more amenable to Direct Selective Laser Sintering than M2
powders. Densities up to 90% are possible with H13 powder compared with 70% for M2. The
relationship between alloy composition, microstructure, post-scanned density and scan
conditions will be discussed for single track, single layer and multi-layer constructions.","The research reported in this paper is a joint project between the Universities of Bradford, Leeds
and Liverpool, funded by the UK Engineering and Physical Sciences Research Council under
Grant Number GR/R32222.",,,,,
"['Dhar, Joni', 'Lopez, Lazaro', 'Zhang, Shanshan', 'Xu, Ben', 'Uddin, Jasim', 'Li, Jianzhi']",2021-12-06T22:29:59Z,2021-12-06T22:29:59Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90699', 'http://dx.doi.org/10.26153/tsw/17618']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'high entropy alloy', 'microstructure', 'additive manufacturing']",Direct Selective Laser Synthesis of CuCrFeNiTiAl High Entropy Alloy from Elemental Powders through Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fb39ec0-8e43-442a-8cfe-ceb77e4adbee/download,University of Texas at Austin,"This study investigated the synthesis of CuCrFeNiTiAl high entropy alloy (HEA) from pure
elements using selective laser melting (SLM). The objectives are to validate the feasibility of the
HEA fabrication from elemental powder materials, and to examine the effect of various process
conditions in SLM, such as laser power, point distance and laser exposure time, on the
microstructures formed. The as-built samples under high, medium and low energy densities were
characterized by X-ray diffraction (XRD), and the microstructures were observed using scanning
electron microscopy (SEM). The XRD results showed that five major crystal structure phases
(hexagonal, monoclinic, orthorhombic, body-centered cubic and rhombohedral) were present in
all samples. Fine-grained phases were noticed on the sample surface with non-uniform
microstructural distribution. Such phases in high and low energy density samples were observed
polygonal while round-shaped microstructures were observed for samples prepared under medium
energy density conditions. Also, the grain size was proportional to energy levels of the fabrication
process. Large size and clustered structures are prominent in samples produced under high energy
density.",,,,,,
"['Starly, B.', 'Lau, A.', 'Sun, W.', 'Lau, W.', 'Bradbury, T.', 'Youssef, A.', 'Gaylo, C.']",2019-11-20T16:06:00Z,2019-11-20T16:06:00Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78464', 'http://dx.doi.org/10.26153/tsw/5549']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Direct Slicing,Direct Slicing of STEP Based NURBS Models for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ffb9cdb-8839-4644-a84d-f7b90bc6bbd9/download,,"Direct slicing of CAD models to generate process planning instructions for solid freeform
fabrication may overcome inherent disadvantages of using STL format in terms of the process
accuracy, ease of file management, and incorporation of multiple materials. This paper will
present the results of our development of a direct slicing algorithm for layered freeform
fabrication. The direct slicing algorithm was based on a neutral, international standard (ISO
10303) STEP-formatted NURBS geometric representation and is intended to be independent of
any commercial CAD software. The following aspects of the development effort will be
presented: 1) Determination of optimal build direction based upon STEP-based NURBS models;
2) Adaptive subdivision of NURBS data for geometric refinement; and 3) Ray-casting slice
generation into sets of raster patterns. Feasibility studies applying the direct slicing algorithm to
example models and the generation of fabrication planning instructions involving multi-material
structures will also be presented.",,,,,,
"['Shishkovsky, IV.', 'Makarenko, A.G.', 'Petrov, A.L']",2018-11-28T20:51:26Z,2018-11-28T20:51:26Z,1997,Mechanical Engineering,doi:10.15781/T2K64BC7C,http://hdl.handle.net/2152/70329,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['direct SLS', 'eutectic powder compositions', 'control exothermic reaction of combustion.']",Direct SLS of powder compositions used for self-propagating high-temperature synthesis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e5d32d38-6eff-47be-a68d-2de4fbb97466/download,,"The conditions of a direct selective laser sintering (SLS) were resea;rched experimental in
a volume and by layers for the eutectic and near-eutectic powder compositions, which
usually used for the self-propagating high-temperature synthesis (SHS) technology. It was
shown a possibility to realise during SLS process a control exothermic reaction of
combustion exactly in the focus ofew-Iaser beam on Nd-YAG. The necessary parameters of
a laser influence (a power, scan velocity and diameter'of the laser beam), a dispersion and
composition of the powder mixtures were determined for the such regime. The 3D parts
from intermetallic compounds were created without any post-process procedures, that
expands the functional opportunities ofthe sintering models.",,,,,,
"['Sparks, Todd', 'Liou, Frank']",2020-03-11T15:33:06Z,2020-03-11T15:33:06Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80253', 'http://dx.doi.org/10.26153/tsw/7272']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Laser Metal Deposition,Direct-to-Part Machining Waste Recycling using Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e542d4a0-3355-48e1-bb20-8d6c49d13546/download,,,,,,,,
"['Dimos, D.', 'Yang, P.', 'Garino, TJ.', 'Raymond, M.V.', 'Rodriguez, M.A.']",2018-11-28T17:35:57Z,2018-11-28T17:35:57Z,1997,Mechanical Engineering,doi:10.15781/T2BN9XP08,http://hdl.handle.net/2152/70323,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['High reliability', '3-D architectures', 'fabrication processes']","Direct-Write Fabrication of Integrated, Multilayer Ceramic Components",Conference paper,https://repositories.lib.utexas.edu//bitstreams/ecb0271b-85e7-406e-880c-3cdb88279b16/download,,"The need for advanced (electronic) ceramic components with smaller size, greater
functionality, and enhanced reliability requires the ability to integrate electronic ceramics in
complex 3-D architectures. For rapid prototyping and small-lot manufacturing, traditional tape
casting and screen printing approaches are poorly suited. To address this need, we are developing
a direct-write approach for fabricating highly integrated, multilayer components using a
micropen to deposit slurries in precise patterns. With this technique, components can be
constructed layer by layer, simplifying fabrication. It can also be used to produce structures
combining several materials in a single layer. The parts are either cofired or sequentially fired,
after each layer is deposited. Since differential shrinkage can lead to defects in these multilayer
structures, we are characterizing the sintering behavior ofindividua1layers. This technique has
been used to fabricate devices such integrated RC filters, multilayer voltage transformers, and
other passive components. The direct-write approach provides the ability to fabricate
multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid
way.",,,,,,
"['Yang, M.', 'Parvez, M.M.', 'Sparks, T.', 'Babalola, S.', 'Newkirk, J.W.', 'Chandrashekhara, K.', 'Bartlett, L.N.', 'Liou, F.']",2023-03-29T16:51:00Z,2023-03-29T16:51:00Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117686', 'http://dx.doi.org/10.26153/tsw/44565']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Directed Energy Deposition (DED)', 'AF9628 Low Alloy Steel', 'Laser Power', 'Scan speed', 'Cooling Rate', 'Micro-tensile Test (YS, UTS, Elongation)']",Directed Energy Deposition Processing-Performance Relationship of AF9628,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7477535-3546-4dc6-83dc-a0cfdcee55b7/download,,"AF9628 low alloy steel is a novel steel known for its low cost, high hardness, and 
outstanding tensile performance. However, the processing methods of AF9628 have been less 
studied in the additive manufacturing field. As the balance of hardness and tensile results is closely 
related to the cooling process during manufacturing process window and its relationship to 
resultant tensile properties was explored. By using the DED method, specimens of this steel were 
successfully fabricated, and tensile test results were obtained. The AF9628 steel can be 
manufactured for tailored properties with the DED process by controlling the cooling method. This 
work was funded by ARL - GVSC under cooperative agreement W911NF-20-2-0251.",,,,,,
"['Imediegwu, Chikwesiri', 'Shaffer, Milo', 'Ryan, Mary', 'Panesar, Ajit']",2024-03-27T03:50:32Z,2024-03-27T03:50:32Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124476', 'https://doi.org/10.26153/tsw/51084']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['topology optimisation', 'nanoarchitecture', 'battery']",Discovery of next-generation battery electrodes using topology optimisation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/42edfa21-f380-4dd1-9bda-49d1b35d747e/download,University of Texas at Austin,"Energy storage systems (ESSs) are essential components for the delivery of uninterrupted
renewable energy of the future. A key stride towards the development of these systems revolves
around the design of insertion-electrode batteries (IEBs). However, battery cell performance
metrics of capacity and rate capability in these batteries are limited by inefficient ion and electron
transport due to the complex transport channels the ions must navigate to reach storage sites – a
fundamental limitation of slurry-cast (SC) type electrodes. We present a gradient-driven approach
to derive optimal electrode architecture, constrained only by the underlying multiphysics system
defining transport mechanisms in and across solid and liquid phases. The derived framework
challenges the traditional manufacturing techniques for electrodes, inspiring novel strategies for
deriving new high-performance electrodes.",,,,,,
"['Menezes, C.', 'Turner, C.']",2021-12-07T17:27:07Z,2021-12-07T17:27:07Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90730', 'http://dx.doi.org/10.26153/tsw/17649']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['discrete element modeling', 'printing parameters', 'fused deposition modeling']",Discrete Element Modeling of Fused Deposition Modeling Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/32e32f16-36da-484a-a3c3-d85a08ff14bb/download,University of Texas at Austin,"Fused Deposition Modeling components show anisotropic material properties as a result
of the difference in bonding strengths between inter- and intra-layer particles. This difference
occurs due to temperature gradient of the deposited filaments which affects the filament adhesion
as well as due to the presence of voids or other discontinuities in the printed object. Discrete
Element Modelling (DEM) is a discontinuous methodology which follows the idea of treating
filaments as discrete rigid particles with simplified geometries for calculating the thermal
interactions between the particles. Models using this approach allow the investigators to correlate
the adhesion effects between filaments based on experimental data which ultimately will allow for
optimization of the relevant printing parameters.",,,,,,
"['Jackson, Brad', 'Wood, Kris', 'Beaman, Joseph J.']",2019-09-23T15:28:05Z,2019-09-23T15:28:05Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75936', 'http://dx.doi.org/10.26153/tsw/3035']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Arrays,Discrete Multi-Material Selective Laser Sintering (M2 SLS): Development for an Application in Complex Sand Casting Core Arrays,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f266dfd7-b8f6-49c1-b4c6-16650801a8bc/download,,"Conventional sand casting processes often take many weeks or months to produce the tooling required for a casting, in particular the fabrication of sand core arrays for hollow features in a casting. SLS is already being applied to produce complex sand core geometries and reduce production times, but a new development of discretely laying down two different materials and removing one after sintering will allow even more complex geometries and drastically decrease the production times of sand cores. Two of the most significant problems in the current use of SLS for sand cores are the mechanical removal of unsintered powder and damage during part breakout. The second discrete material serves as a support medium through the build and fabrication of the sand core and is removed before casting; the sacrificial second material increases green strength and eliminates time consuming post-processing. The development and plan for implementation of the discrete M2 SLS process is presented.",,,,,,
"['Pal, D.', 'Stucker, B.E.']",2021-09-30T19:07:13Z,2021-09-30T19:07:13Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88282', 'http://dx.doi.org/10.26153/tsw/15223']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['dislocation density based model', 'crystal plasticity quasi-static finite element', 'Ultrasonic Consolidation', 'dislocation density']",Dislocation Density Based Finite Element Modeling of Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4fa1532-9f10-4279-8c93-94c2a0ffa28e/download,University of Texas at Austin,"A dislocation density based constitutive model has been developed and implemented into
a crystal plasticity quasi‐static finite element framework. This approach captures the statistical
evolution of dislocation structures and grain fragmentation at the bonding interface when
sufficient boundary conditions pertaining to the Ultrasonic Consolidation process are prescribed.
Hardening is incorporated using statistically stored and geometrically necessary
dislocation densities (SSDs and GNDs), which are dislocation analogs of isotropic and kinematic
hardening respectively. The GND considers strain‐gradient and thus renders the model
size‐dependent. The model is calibrated using experimental data from published refereed
literature and then validated for the Aluminum 3003 alloy.",,,,,,
"['Pal, D.', 'Stucker, B.E.']",2021-10-04T21:58:33Z,2021-10-04T21:58:33Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88363', 'http://dx.doi.org/10.26153/tsw/15302']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['dislocation density', 'crystal plasticity based finite element modeling', 'Ultrasonic Consolidation']",Dislocation Density Crystal Plasticity Based Finite Element Modeling of Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f4a528b-fdf9-4bff-ab29-4eef12651030/download,University of Texas at Austin,"A dislocation density based constitutive model has been developed and implemented into
a crystal plasticity quasi-static finite element framework. This approach captures the statistical
evolution of dislocation structures and grain fragmentation at the bonding interface when
sufficient and necessary boundary conditions pertaining to the Ultrasonic Consolidation (UC)
process are prescribed.
The hardening is incorporated using statistically stored and geometrically necessary
dislocation densities (SSDs and GNDs) which are dislocation analogs of isotropic and kinematic
hardening respectively. Since, the macroscopic boundary conditions during UC involves cyclic
sinusoidal simple shear loading along with constant normal pressure, the cross slip mechanism
has been included in the evolution equation for SSDs. The inclusion of cross slip promotes slip
irreversibility, dislocation storage and, hence, cyclic hardening during the UC. The GND
considers strain-gradient and thus renders the model size-dependent. The model is calibrated
using experimental data from published refereed literature for simple shear deformation of single
crystalline pure aluminum alloy and uniaxial tension of polycrystalline Aluminum 3003-H18
alloy. The model also considers the tension-compression asymmetry in case the model is applied
for deformation processes in hexagonal close packed pure Titanium and its alloy counterparts
which will be investigated further in our proposed research program. One of the significant
macroscopic contributions from this model development is to successfully accommodate the
elasto-plastic contact problem involved in UC.
The model also incorporates various local and global effects such as friction, thermal
softening, acoustic softening, surface texture of the sonotrode and initial mating surfaces and
presence of oxide-scale at the mating surfaces which further contribute significantly specifically
to the grain substructure evolution at the interface and to the anisotropic bulk deformation away
from the interface during UC in general. The model results have been predicted for Al-3003 H-18 alloy undergoing UC. A good agreement between the experimental and simulated results has
been observed for the evolution of linear weld density and anisotropic global strengths
macroscopically. Similarly, microscopic observations such as embrittlement due to grain
substructure evolution and broken oxide layer at the UC interface has been also demonstrated by
the simulation.",,,,,,
"['Göynük, T.', 'Onem, O.U.', 'Yasa, E.', 'Karakaya, I.']",2024-03-25T23:33:57Z,2024-03-25T23:33:57Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124338', 'https://doi.org/10.26153/tsw/50946']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['vacuum brazing', '17-4PH stainless steel', 'BNi-2 filler material', 'additive manufacturing']",DISSIMILAR VACUUM BRAZING OF ADDITIVE MANUFACTURED 17-4PH STAINLESS STEEL TO CONVENTIONAL 304 AND 17-4 STAINLESS STEEL BY BNI-2 BRAZING FILLER MATERIAL,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97ae3324-b4ce-458e-9a78-02e4745649ea/download,University of Texas at Austin,"Vacuum brazing process of 17-4PH stainless steel, which was manufactured using additive
manufacturing, as well as conventional AISI304 and 17-4PH stainless steel alloys was investigated. The brazing
process was conducted at 1050°C for 20 minutes under 10-6 Torr, using BNi-2 filler material. Various aspects of
the vacuum brazed parts were analyzed, including their microstructure, wetting behavior and mechanical strength.
To evaluate the wetting behavior, the contact angle and wetted area were measured using optical microscopy. The
microstructures were examined using Scanning Electron Microscopy and Energy Dispersive Spectroscopy
techniques. Additionally, tensile testing was performed on the joints to assess the influence of surface roughness
and brazing of different materials on the strength of the brazed parts.",,,,,,
"['Lefky, Christopher S.', 'Nassar, Abdalla R.', 'Simpson, Timothy', 'Hildreth, Owen J.']",2021-10-28T20:57:04Z,2021-10-28T20:57:04Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89698,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['direct energy deposition', 'powder bed fusion', 'dissolvable metal supports', 'metal supports', 'chemical stability', 'electrochemical stability']",Dissolvable Metal Supports for Printed Metal Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8247faaa-1218-4dcc-8159-1fe6cab92d5a/download,University of Texas at Austin,"Temporary support structures are an inconvenient necessity in Direct Energy Deposition (DED) and Powder
Bed Fusion (PBF) printed metal parts. Used to reduce thermal distortion and brace large overhands, support
structures often require post-print machining operations to remove, adding costs and processing delays. This
preliminary work demonstrates that soluble, sacrificial metal supports can be fabricated in DED and PBF
printers by taking advantage of small differences in the chemical and electrochemical stability between different
metallic alloys. For DED printing, we demonstrate this process by printing stainless steel bridge structure with
90˚ overhang and printed carbon steel acting as a sacrificial support. For PBF printing, a PBF printed stainless
steel part was first printed and then carburized to reduce the free chromium at the surface. Since the
support/component interface is only ~100 μm in size, this interface becomes highly susceptible to chemical and
electrochemical dissolution. In both cases, the component was separated from the supports in a solution of
nitric acid and KCl under mild electrochemical bias. No machining, grinding, or finishing operations were
required to remove the metallic supports. These novel approaches introduce new capabilities to additive
manufacturing that will drastically reduce the post-processing needed for 3D printed metal components.",,,,,,
"['Hlifka, Brian M.', 'Kinzel, Edward C.']",2024-03-26T20:43:09Z,2024-03-26T20:43:09Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124403', 'https://doi.org/10.26153/tsw/51011']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'optical fiber', 'fused filament fabrication']",Distributed Optical Fiber Testing for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e43ff7c0-7569-4bac-bb08-fa813e4d6fdb/download,University of Texas at Austin,"This paper explores optical fiber's use for in-situ inspection of additive manufacturing.
Single-mode SMF-28 optical fiber can be placed on the build plate to monitor the printing process
or embedded in the part. Distributed measurements using optical backscattering reflectometry
(OBR) resolve the strain along the optical fiber and the temperature. OBR-enabled sensing is
demonstrated for the fused filament fabrication (FFF) process. The small diameter (0.125 mm) of
SMF-28 lends itself to embedding in FFF prints. This enables laying the fiber into the part, which
provides continued sensing for the details in use. Knowledge of the process and the fiber
arrangement allows heating from the deposition head to be distinguished from stress-driven strain.
Calibration of the fiber arrangement is discussed, as well as a comparison with process modeling.",,,,,,
"['Brackett, D.', 'Ashcroft, I.', 'Hague, R.']",2021-10-05T14:55:31Z,2021-10-05T14:55:31Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88386', 'http://dx.doi.org/10.26153/tsw/15325']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['lattice cells', 'tetrahedral cells', 'dithering method', 'error diffusion', 'additive manufacturing']",A Dithering Based Method to Generate Variable Volume Lattice Cells for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb3b7811-a88f-48c7-a3f1-032427bd0e9a/download,University of Texas at Austin,"This paper covers the principles of a novel method to efficiently spatially vary the size of
tetrahedral cells of a lattice structure, based upon finite element analysis stress results. A
dithering method, specifically error diffusion, is used to represent a grayscale stress fringe with
variably spaced black dots. This enables linkage of the spacing between lattice cell vertices to
stress level thereby providing a functional variation in cell density. This method is demonstrated
with a simple test case in 2D and the steps involved for extension to 3D are described.",,,,,,
"['Nyrhilä, Olli', 'Kotila, Juha', 'Latikka, Maria', 'Hänninen, Jouni', 'Syvänen, Tatu']",2020-03-09T15:18:35Z,2020-03-09T15:18:35Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80195', 'http://dx.doi.org/10.26153/tsw/7214']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Direct Metal Laser Sintering,DMLS and Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2c42d9ba-1e5b-4812-a578-e543691d0d0c/download,,"Direct Metal Laser Sintering (DMLS) has been used for manufacturing
prototypes, functional metal components and prototype tools for more than 10 years.
During this period the technology has advanced to a level where direct production of
complex metallic parts for various applications is everyday life and manufacturing with
its various challenges is its main target. The shift from prototyping to production requires
changes in the technology and also in the organizations taking part in the shift.
This paper presents the latest status of the DMLS technology and materials
development trends for different application areas using EOSINT M270 laser sintering
machine. Commercially launched materials include presently biomedical materials like
Titanium and Cobalt Chrome alloys, ultra high strength Maraging Steel alloy, Stainless
Steels and other high-end engineering materials. In addition, there are many materials
which have been developed for evaluation purposes, waiting for industrial applications.",,,,,,
"['Ray, Nachiketa', 'Bisht, Manisha', 'Thijs, Lore', 'Van Vaerenbergh, Jonas', 'Coeck, Sam']",2021-11-15T22:33:04Z,2021-11-15T22:33:04Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90297', 'http://dx.doi.org/10.26153/tsw/17218']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Ti-6Al-4V', 'process optimization', 'monitoring', 'X-ray CT']",DMP Monitoring as a Process Optimization Tool for Direct Metal Printing (DMP) of Ti6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38eaf755-bb4f-4bf0-8c6d-64316922eaba/download,University of Texas at Austin,"Metal Additive Manufacturing (AM) has evolved as a production technique for rapid
prototyping as well as high volume precision manufacturing. In this work, DMP Monitoring, a
new feature of 3D Systems’ direct metal printer, ProX® DMP 320 has been used as a tool for
process parameter optimization. The effect of the variations of process parameters like layer
thickness, laser power, scan speed and hatch spacing on the physical and mechanical properties
of the additively manufactured Ti-6Al-4V samples have been investigated. In addition to the
conventional post-processing evaluation methods like Archimedes’ density, X-ray CT and
tensile testing, new in-situ process monitoring tools are assessed and compared with the
traditional evaluation methods.",,,,,,
"['Bertoldi, M.', 'Yardimci, M', 'Pistor, C. M', 'Guceri, S. I.']",2019-02-20T17:43:24Z,2019-02-20T17:43:24Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73456', 'http://dx.doi.org/10.26153/tsw/608']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['RP', 'PC-based controllers']",Domain Decomposition and Space Filling Curves in Toolpath Planning and Generation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/57ac4954-5e4e-4261-85f1-86f57cbe1e60/download,,"Ever increasing computer performance, along with significant developments in CADI
CAM technology and high precision digital motion controllers lead to rapid and significant
developments in the field ofrapid prototypingjfabrication. Together, these elements offer a wide
range of possible approaches in the toolpath planning issue; two main sets have been analyzed
and applied to Fused Deposition Modeling process.
Domain decomposition is a frequently used technique in computational methods. Within
the context of present study, this approach is used to divide arbitrary layer geometries into
smaller regions of simpler shape. A foreseeable advantage in such an approach is maximizing
strength characteristics through thermal management. This is achieved by utilizing space filling
curves which are mathematical entities that offer the possibility of building a wide range of
structures, covering the surface of a single layer with one continuous curve. To evaluate the
proposed concepts, ABS structures and ceramic green bodies have been successfully built.",,,,,,
"['Williams, Glen', 'Baldwin, Martha', 'Simpson, Timothy W.', 'Meisel, Nicholas A.', 'McComb, Christopher']",2024-03-27T03:20:54Z,2024-03-27T03:20:54Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124462', 'https://doi.org/10.26153/tsw/51070']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['machine learning', 'additive manufacturing', 'data augmentation']",Dreaming of Data: Examining Data Augmentation for Machine Learning in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7019185b-6aa7-4877-99ed-93c429809faf/download,University of Texas at Austin,"The data generated during additive manufacturing (AM) practice can be used to train machine
learning (ML) tools to reduce defects, optimize mechanical properties, or increase efficiency. In
addition to the size of the repository, emerging research shows that other characteristics of the data
also impact suitability of the data for AM-ML application. What should be done in cases for which
the data in too small, too homogeneous, or otherwise insufficient? Data augmentation techniques
present a solution, offering automated methods for increasing the quality of data. However, many
of these techniques were developed for machine vision tasks, and hence their suitability for AM
data has not been verified. In this study, several data augmentation techniques are applied to
synthetic design repositories to characterize if and to what degree they enhance their performance
as ML training sets. We discuss the comparative advantage of these data augmentation techniques
across several canonical AM-ML tasks.",,,,,,
"['Chianrabutra, S.', 'Mellor, B.G.', 'Yang, S.']",2021-10-12T20:03:04Z,2021-10-12T20:03:04Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88728', 'http://dx.doi.org/10.26153/tsw/15662']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['material delivery device', 'dry powder', 'dry powder printing', 'multiple material additive manufacturing', 'additive manufacturing']",A Dry Powder Material Delivery Device for Multiple Material Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/187aa596-ba26-44b8-9331-d1188c05608a/download,University of Texas at Austin,"This research is to develop a novel material delivery device for a next generation
additive manufacturing system which is capable of directly manufacturing objects by
depositing several materials layer by layer. The successful deposition of multiple material
layers by using this novel dry powder printing technique reveals its great potential as a means
of incorporating multiple materials in the traditional additive manufacturing process since
this technology is suitable for a wide range of materials and it has the capability to
manufacture 2D layers composed of multiple materials. This paper will outline the basics of
the dry powder printing technology and present and discuss selected experimental studies
from our research.",,,,,,
"['Lu, Xuesong', 'Yang, Shoufeng', 'Chen, Lifeng', 'Evans, Julian R. G.']",2020-03-05T19:39:22Z,2020-03-05T19:39:22Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80147', 'http://dx.doi.org/10.26153/tsw/7168']",eng,2006 International Solid Freeform Fabrication Symposium,Open,selective laser sintering,Dry Powder Microfeeding System for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/48c2971b-5da9-466c-ba85-951a1556c331/download,,"Second generation SFF techniques allow both composition and shape to be downloaded
directly from a computer file so that 3D functionally graded materials (FGM) can be assembled.
Methods for multi-material deposition are also needed in combinatorial research, colour
management and pharmaceutical dosing. In this work, computer-controlled microfeeding systems
using ultrasonic vibration of a capillary were built. A wide range of stable flow rate control and
switching control were achieved in the acoustic vibration system, and uniform powder doses
were obtained in the ultrasonic system. The experimental results show that the nozzle diameter,
transmission fluid depth, waveforms, voltage amplitude, frequency and oscillation duration all
influence the dose mass. Among these factors, the nozzle diameter, voltage amplitude and
oscillation duration can be used to control the dose mass. Raster printing of patterns with various
resolution and dot size are demonstrated.",,,,,,
"['Glazer, M.', 'Vail, N.K.', 'Barlow, J.W.']",2018-05-03T19:58:29Z,2018-05-03T19:58:29Z,1993,Mechanical Engineering,doi:10.15781/T2057D92D,http://hdl.handle.net/2152/65076,,1993 International Solid Freeform Fabrication Symposium,Open,"['Alumina', 'Silica Colloid', 'Drying']",Drying of Colloidal Binder Infiltrated Ceramic Green Parts Produced by Selective Laser Sintering™,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f217e37f-af94-4dd4-b254-43ab0a04f798/download,,"Colloidal ceramic binders have been used to strengthen ceramic
green shapes produced by Selective Laser Sintering. This paper
focuses on the effectiveness of the colloid infiltration with
respect to the physical properties of the colloidal binder. Mass
gains, strength gains, and dimensional changes resulting from
infiltration were monitored. Controlled drying experiments were
conducted to predict the factors influencing drying times for
complex shapes.",,,,,,
"['Marshall, G.', 'Young, W.J. Jr', 'Shamsaei, N.', 'Craig, J.', 'Wakeman, T.', 'Thompson, S.M.']",2021-10-19T19:05:58Z,2021-10-19T19:05:58Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89325,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Direct Laser Deposition', 'Laser Engineered Net Shaping', 'thermographic monitoring', 'dual monitoring', 'Ti-6Al-4V', 'titanium cylinders']",Dual Thermographic Monitoring of Ti-6Al-4V Cylinders During Direct Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2a02e019-64e6-454c-a58b-b41b54856ce4/download,University of Texas at Austin,"Understanding the thermal phenomena associated with Direct Laser Deposition (DLD) is
necessary to begin manipulating fabricated part properties. In this study, a thermally monitored
Laser Engineered Net Shaping (LENS) system is used with time-invariant (uncontrolled) build
parameters to construct Ti-6Al-4V cylinders with two different build paths. Both paths utilize a
circular contour with serpentine hatch fill; however, successive layer patterns are varied and the
effects compared between 90° and 120° angular pattern shifts. During fabrication, the part’s
thermal history and melt pool temperature are recorded via an in-chamber infrared (IR) camera
and a dual-wavelength (DW) pyrometer, respectively. These tools are used for non-destructive
thermographic inspection (NTI) of the part to ensure target quality and/or microstructure. A
unique calibration method for the IR camera utilizing the DW pyrometer data is presented and a
calibration correction factor was utilized for high temperature ranges. The melt pool was found
to be 40-50% superheated reaching temperatures up to 2500 ºC at times. Temperature
characteristics of two different layers were compared for different hatching patters, and the
results show that for a given point in time, maximum temperatures can vary based on laser raster.
Temperature gradients varied and peaked at about 1000 ºC/mm along the diameter of the small
rods. This can lead to anisotropy in microstructural and mechanical properties allowing for
unique property growth per build path. Cooling rates within the melt pool appear to increase as
maximum melt pool temperature increases, for instance, from 16,000 ºC/s – 41,000 ºC/s.",,,,,,
"['Obielodan, J.O.', 'Stucker, B.E.']",2021-09-29T22:43:24Z,2021-09-29T22:43:24Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88223', 'http://dx.doi.org/10.26153/tsw/15164']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'dual-material minimum-weight structures', 'ultrasonic consolidation', 'multi-material', 'fabrication']",Dual-Material Minimum Weight Structures Fabrication Using Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ca8fe7b6-0f96-4e99-884e-12e12ff521e1/download,University of Texas at Austin,"The multi-material capability of additive manufacturing (AM) processes has created opportunities for structural designs that would otherwise be impossible. This work involves the development of a methodology for fabricating dual-material minimum-weight structures using ultrasonic consolidation (UC). Sample structures were designed, fabricated and tested for load carrying capabilities. Analyses of results show that dual-material minimum weight structures made of Al3003/MetPreg® and Al3003/Ti composite material members can withstand significantly higher strain energy densities up to the point of failure than similar structures made
of Al 3003 alone. This is an indication that UC can be effectively used to fabricate multi-material structures for real life applications.",,,,,,
"['Yigit, Ismail Enes', 'Lazoglu, Ismail']",2021-11-18T18:35:35Z,2021-11-18T18:35:35Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90460', 'http://dx.doi.org/10.26153/tsw/17381']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['support structures', 'dynamic', 'additive manufacturing']",Dynamic Build Bed for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/416d24c3-012a-4c41-8581-8fd892817841/download,University of Texas at Austin,"Compared to subtractive manufacturing, additive manufacturing generally has low
material waste. However, models with large overhangs require manufacturing of support
structures which ends up as waste material. This paper proposes the use of a dynamic build bed
for reducing support structures. The bed consists of an array of actuated pins which move in the
build orientation. Each pin can be individually moved to the correct height for supporting the
given model. Two separate applications of the build bed are investigated. In the first application,
the dynamic build bed is used as support structures in deposition-based AM methods. The pins
individually raise out of the build bed to support the overhang geometry at the given deposition
height. The second application is in powder-based AM methods. In the second application, the
pins are used to fill the space of the powder where the geometry will not occupy. The pins are
individually lowered in the build orientation to make space for a new powder layer. Thus,
saving excessive deposition of powder.",,,,,,
"['Johnson, Kevin', 'Allen, Aimee', 'Blough, Jason', 'Barnard, Andrew', 'Labyak, David', 'Hartwig, Troy', 'Brown, Ben', 'Soine, David', 'Cullom, Tristan', 'Kinzel, Edward', 'Bristow, Douglas', 'Landers, Robert']",2021-11-18T17:30:19Z,2021-11-18T17:30:19Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90438', 'http://dx.doi.org/10.26153/tsw/17359']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['defect detection', 'FEA simulation', 'additive manufacturing', 'internal defects']",Dynamic Defect Detection in Additively Manufactured Parts using FEA Simulation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9cbfb33d-3673-4751-a0ba-c510578f574d/download,University of Texas at Austin,"The goal of this paper is to evaluate internal defects in additively manufactured (AM)
parts using FEA simulation. The resonant frequencies of parts are determined by the stiffness
and mass involved in the mode shape at each resonant frequency. Voids in AM parts will change
the stiffness and mass therefore shift the resonant frequencies from nominal. This paper will
investigate the use of FEA to determine how much a void size, shape, and location will change
the resonant frequencies. Along with where the optimal input and response locations are in order
to find these frequency changes. The AM part evaluated in this work includes a common tensile
bar and hammer shaped part evaluated individually and as a set of parts that are still attached to
the build plate.","This work was funded by the Department of Energy’s Kansas City National
Security Campus which is operated and managed by Honeywell Federal Manufacturing
Technologies, LLC under contract number DE-NA0002839.",,,,,
"['Pan, Yayue', 'Dagli, Chintan']",2021-10-19T19:01:18Z,2021-10-19T19:01:18Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89324,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'vat photopolymerization', 'stereolithography', 'resolution control', 'build size']",Dynamic Resolution Control in a Laser Projection Based Stereolithography System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59fbbbab-46c3-4d31-aa6b-4c82162c7915/download,University of Texas at Austin,"In a typical Additive Manufacturing system, it is critical to make a trade-off between the
resolution and build area for applications in which varied dimensional sizes, feature sizes, and
accuracies are desired. The lack of the capability in adjusting resolution dynamically during
building processes limits the use of AM in fabricating complex structures with big layer areas
and small features. In this paper, a novel AM system with dynamic resolution control by
integrating a laser projection in vat photopolymerization process is presented. Theoretical models
and parameter characterizations are presented for the developed AM system. Accordingly, the
process planning and mask image planning approaches for fabricating models with varied
dimensional sizes and feature sizes have been developed. Multiple test cases based on various
types of structures have been performed.",,,,,,
"['Terrazas, C.A.', 'Gaytan, S.M.', 'Mireles, J.', 'Frigola, P.', 'Espalin, D.', 'Wicker, R.B.']",2021-10-13T20:17:37Z,2021-10-13T20:17:37Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88776', 'http://dx.doi.org/10.26153/tsw/15710']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['high purity niobium', 'superconducting radio frequency', 'electron beam melting', 'additive manufacturing']",EBM Fabrication and Characterization of High Purity Niobium for Superconductor Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d11406f8-a4ff-4985-90ab-8c210fcdcf9d/download,University of Texas at Austin,"Superconducting radio frequency (SRF) cavities are used to accelerate charged particles
to near the speed of light for elemental studies. Currently, SRF cavities are typically fabricated
using different forming processes including deep-drawing and spinning to mechanically shape
niobium into the desired geometry. This research presents the development of processing
parameters for high purity niobium (powder size range of 25-125μm) using electron beam
melting additive manufacturing technology. Fabrication parameters were improved to obtain
dense parts in a time-efficient manner. A specific procedure was used to maintain powder
purity, and powder chemistry was monitored at different stages of fabrication. In addition, a
series of experiments were performed to obtain 99.9% dense parts and a maximum building
height of ~85mm.",,,,,,
"['Post, B.K.', 'Lind, R.F.', 'Lloyd, P.D.', 'Kunc, V.', 'Linhal, J.M.', 'Love, L.J.']",2021-10-28T15:36:23Z,2021-10-28T15:36:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89664,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['economics', 'processing time', 'fused deposition modeling', 'BAAM', 'additive manufacturing']",The Economics of Big Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/37595a23-1b45-46e4-bed7-82026e24d8b6/download,University of Texas at Austin,"Case studies on the economics of Additive Manufacturing (AM) suggest that processing time is the dominant
cost in manufacturing. Most additive processes have similar performance metrics: small part sizes, low
production rates and expensive feedstocks. Big Area Additive Manufacturing is based on transitioning polymer
extrusion technology from a wire to a pellet feedstock. Utilizing pellets significantly increases deposition speed
and lowers material cost by utilizing low cost injection molding feedstock. The use of carbon fiber reinforced
polymers eliminates the need for a heated chamber, significantly reducing machine power requirements and size
constraints. We hypothesize that the increase in productivity coupled with decrease in feedstock and energy
costs will enable AM to become more competitive with conventional manufacturing processes for many
applications. As a test case, we compare the cost of using traditional fused deposition modeling (FDM) with
BAAM for additively manufacturing composite tooling.",,,,,,
"['Martof, Ashley', 'Gullapalli, Ram', 'Kelly, Jon', 'Rea, Allison', 'Lamoncha, Brandon', 'Walker, Jason M.', 'Conner, Brett', 'MacDonald, Eric']",2021-11-09T14:39:15Z,2021-11-09T14:39:15Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90082', 'http://dx.doi.org/10.26153/tsw/17003']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'sand molds', 'sand casting', 'economics', 'CAD models', 'additive manufacturing']",Economies of Complexity of 3D Printed Sand Molds for Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/278b71cd-cfa5-405c-9b1d-861608150868/download,University of Texas at Austin,"Additive Manufacturing (more commonly referred to as 3D printing) is resulting in a
metamorphosis of the sand casting industry as 3D printed sand molds enable castings of
unmatched geometric complexity. The manifold benefits of these molds include: (1) the
integration of structural elements such as periodic lattices in order to optimize weight versus
strength; (2) the structural inclusion of unique features such as embossed part numbers and/or
other details of the production history; and (3) complex geometries that generate new casting
applications not possible previously. Additive Manufacturing is often described as providing
“complexity for free”, which may not be entirely precise but generally holds true and the
identification of castings that are sufficiently complex to benefit from 3D printing is generally
left to the intuition of the designer or foundry. New software tools are necessary for foundries to
discover opportunities in which the additional costs of 3D printing are compensated by the
benefits of increased structural complexity. This paper describes a complexity evaluation tool
that scores CAD models to determine the most economical casting approach based on slicing and
2D geometry evaluation. The three potential outcomes include (1) traditional sand casting,
(2) AM­-enabled sand casting and (3) a hybrid of the two with 3D printed cores in traditional
casting flasks.   Several case studies are described and evaluated.",,,,,,
"['Mohammed, Mazher Iqbal', 'Das, Anirudra', 'Gomez-Kervin, Eli', 'Wilson, Daniel', 'Gibson, Ian']",2021-11-02T18:24:08Z,2021-11-02T18:24:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89859,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'recycling', 'FDM', 'EcoPrinting', 'ABS']",EcoPrinting: Investigating the Use of 100% Recycled Acrylonitrile Butadiene Styrene (ABS) for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77b0e111-6ab9-4655-9a12-8f51b4cc0a65/download,University of Texas at Austin,"Many commonly found polymers have the potential to be recycled, such as Acrylonitrile
Butadiene Styrene (ABS), a prevalent 3D printing material. In this study we examine the potential of
using 100% recycled ABS to form filaments for use in Fused Deposition Modelling (FDM) 3D printing.
We then characterise the resulting changes in the printing quality and mechanical properties, over a
single recycling cycle. We found that ABS can undergo recycling and reforming into consistent printer
filaments without the addition of virgin material. However, notable changesin polymer characteristics
were observed, reflected by degradation in mechanical properties during tensile tests and a decrease
in the polymer melt flow, which required reduced raster speed to achieve repeatable prints. Despite
these limitations, we demonstrate that recycling and reprinting is possible with acceptable loss of
material integrity, and could provide unique opportunities for sustainable use of waste ABS using 3D
printing technology.",,,,,,
"['Ippolito, R.', 'Iuliano, L.', 'Gatto, A.']",2018-11-09T16:52:33Z,2018-11-09T16:52:33Z,1996,Mechanical Engineering,doi:10.15781/T25718739,http://hdl.handle.net/2152/69937,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'EDM', 'SEM microscope']",EDM Tooling by Solid Freeform Fabrication & Electroplating Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fd3db20-d2ee-4b90-8933-2c3af3b1e573/download,,"The term ""Rapid Tooling"" refers to the rapid creation of tools in much the same way as Solid
Freeform Fabrication (SFF) means the rapid creation of models. This revolutionary approach
offers both designers and manufacturers attractive advantages in the form of time compression
and cost reduction. Timesaving is of vital significance in the production of EDM electrodes for
the fabrication ofmoulds and dies. The employment ofSFF and electroplating for this purpose is
described. The performances of these new type of electrodes were compared with those obtained
conventionally in terms of dimensional tolerances, surface roughness and working time. The
surfaces ofboth electrodes and workpieces were also examined by SEM microscope.",,,,,,
"Yang, Li",2021-11-08T23:33:04Z,2021-11-08T23:33:04Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90077', 'http://dx.doi.org/10.26153/tsw/16998']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing education', 'additive manufacturing', 'education', 'literature review', 'mini-research projects', 'design competitions']",Education of Additive Manufacturing- An Attempt to Inspire Research,Conference paper,https://repositories.lib.utexas.edu//bitstreams/952490fa-5343-4c8c-b3d7-c26783035fd5/download,University of Texas at Austin,"Although additive manufacturing technologies have undergone significant development in
recent years, significant challenges remain in the understanding of the physics of the processes as
well as many other aspects. Therefore, in the education of the next generation AM workforce,
beside the instruction of existing AM knowledge, it is also of critical importance that the state-of-the-art research subjects and concepts are made aware to the students. In various classroom and
lab setups at University of Louisville, contemporary AM research subjects are introduced to
students via various tools including self-guided literature review, mini-research projects and
design competitions. Through literature review based studies the students not only become aware
of various research subjects, but also have the opportunity to practice critical analysis skills with
new AM knowledge. Through the mini-research and the design competition project-based learning
processes, the students not only gain hands-on experiences with AM practice but also learn about
the research methodologies employed with various AM research subjects.",,,,,,
"['Cohen, Adam', 'Zhang, Gang', 'Tseng, Fan-Gang', 'Mansfeld, Florian', 'Frodis, Uri', 'Will, Peter']",2019-02-19T19:51:59Z,2019-02-19T19:51:59Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73438', 'http://dx.doi.org/10.26153/tsw/590']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Microfabrication', 'micromachining']","EFAB: Batch Production of Functional, Fully-Dense Metal Parts with Micron-Scale Features",Conference paper,https://repositories.lib.utexas.edu//bitstreams/7b3b396e-2270-4378-8db4-de74180b7153/download,,"EFAB (Electrochemical FABrication) is a new SFF process with the potential to economically fabricate
prototypes or mass production quantities of functional, mesoscale-microscale parts and mechanisms. EFAB
generates an entire layer simultaneously-versus serially, as with most SFF. Based on electrodeposition,
EFAB allows ultra-thin layers (2-10 microns, or even submicron) that minimize stairsteps, and generates a
net-shape, fully-dense metal structure that can be homogeneous and isotropic. Minimum feature width is
approximately 25 microns, and can be reduced further. EFAB can be used to manufacture micromachines
and microelectromechanical systems (MEMS), offering significant advantages over current processes: e.g.,
true 3-D geometry, IC compatibility, low capital investment, and process automation.",,,,,,
"['Bontha, Srikanth', 'Klingbeil, Nathan W.']",2020-03-02T15:33:51Z,2020-03-02T15:33:51Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80134', 'http://dx.doi.org/10.26153/tsw/7155']",eng,2006 International Solid Freeform Fabrication Symposium,Open,laser-based material deposition processes,Effect of a Distributed Heat Source on Melt Pool Geometry and Microstructure in Beam-Based Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c687e426-972e-4efb-a042-cf2406bc5915/download,,"The ability to control geometric and mechanical properties of parts fabricated using laser-based
manufacturing processes requires an understanding and control of melt pool geometry and microstructure. With the development of electron beam manufacturing or future beam-based deposition processes, the user may have more control over the distribution of incident energy, so that
beam width becomes a potential process variable. As such, the focus of this work is the effect
of a distributed heat source on melt pool geometry (length and depth) and the thermal conditions
controlling microstructure (cooling rates and thermal gradients) in beam-based solid freeform fabrication. Previous work by the authors has employed the Rosenthal solution for a moving point
heat source to determine the effects of process variables (laser power and velocity) on solidification cooling rates and thermal gradients controlling microstructure (grain size and morphology) in
laser-deposited materials. Through numerical superposition of the Rosenthal solution, the current
work extends the approach to include the effects of a distributed heat source for both 2-D thinwall and bulky 3-D geometries. Results suggest that intentional variations in beam width could
potentially enable significant changes in melt pool geometry without affecting microstructure.",,,,,,
"['Silwal, Bishal', 'Gerdmann, Christopher', 'Migues, Stephen', 'Kardel, Kamram', 'Xu, Shaowen', 'Durrence, Andrew']",2021-11-04T14:14:47Z,2021-11-04T14:14:47Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89966,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'welding arc', 'GTAW', 'ABAM', 'maraging steel', 'PBF']",The Effect of Arc-Based Direct Metal Energy Deposition of PBF Maraging Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b776e4f6-8235-4bac-89ad-3f11fe1edbe0/download,University of Texas at Austin,"With the growing demand of metal based additive manufacturing it is inevitable that the
additively manufactured parts will be used in consolidation with different manufacturing process.
Arc based additive manufacturing is a process used to produce three-dimensional structure using
welding arc as a power source. Powder Bed Fusion (PBF) is an additive manufacturing process
using laser power to generate a three dimensional structure. In this paper, the effect of direct energy
deposition on the PBF has been investigated. The microstructure changes and the melting region
are characterized. A computational fluid dynamics model is used to predict the melt region and
temperature in PBF.",,,,,,
"['Kolan, Krishna C.R.', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Comte, Taylor']",2021-10-11T22:55:21Z,2021-10-11T22:55:21Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88676', 'http://dx.doi.org/10.26153/tsw/15610']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'porosity', 'architecture', 'bone scaffolds', 'borate glass scaffolds', 'bone repair', 'bone replacement']",Effect of Architecture and Porosity on Mechanical Properties of Borate Glass Scaffolds Made by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed1fa2d6-44e9-44f6-b082-bae986ab941a/download,University of Texas at Austin,"The porosity and architecture of bone scaffolds, intended for use in bone repair or
replacement, are two of the most important parameters in the field of bone tissue engineering.
The two parameters not only affect the mechanical properties of the scaffolds but also aid in
determining the amount of bone regeneration after implantation. Scaffolds with five different
architectures and four porosity levels were fabricated using borate bioactive glass (13–93B3)
using the selective laser sintering (SLS) process. The pore size of the scaffolds varied from 400
to 1300 µm. The compressive strength of the scaffolds varied from 1.7 to 15.5 MPa for porosities
ranging from 60 to 30%, respectively, for the different architectures. Scaffolds were soaked in a
simulated body fluid (SBF) for one week to measure the variation in mechanical properties. The
formation of the Hydroxyapatite and in-vitro results are provided and discussed.",,,,,,
"['Bai, Yun', 'Wagner, Grady', 'Williams, Christopher B.']",2021-10-20T22:30:03Z,2021-10-20T22:30:03Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89376,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', 'additive manufacturing', 'copper', 'sintering', '3D printing', 'powder metallurgy']",Effect of Bimodal Powder Mixture on Powder Packing Density and Sintered Density in Binder Jetting of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4f12eafa-bcc3-46a2-bda2-a746b51cfb01/download,University of Texas at Austin,"The Binder Jetting Additive Manufacturing process provides an economical and scalable
means of fabricating complex metal parts from a wide variety of materials. However, the
performance metrics of the resulting sintered parts (e.g., thermal, electrical, and mechanical
properties) are typically lower than traditionally manufactured counterparts due to challenges in
achieving full theoretical density. This can be attributed to an imposed constraint on particle size
and its deleterious effects on powder bed packing density and green part density. To address this
issue, the authors explore the use of bimodal powder mixtures to improve the sintered density and
material properties within the context of copper parts fabricated by Binder Jetting. The
effectiveness of using bimodal powder mixtures in an effort to improve sintered density is studied
in terms of particle size distribution and powder packing density.",,,,,,
"['Torries, Brian', 'Shamsaei, Nima', 'Thompson, Scott']",2021-11-02T13:57:38Z,2021-11-02T13:57:38Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89804,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'fractography', 'build orientation', 'additive manufacturing', 'Ti-6Al-4V']",Effect of Build Orientation on Fatigue Performance of Ti-6Al-4V Parts Fabricated via Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7902be18-2406-4888-b3b3-c28bfe1e1e72/download,University of Texas at Austin,"The effects of build orientation on the fatigue behavior of additively-manufactured Ti-6Al-4V using a Laser-Based Power Bed Fusion (L-PBF) process is investigated. Ti-6Al-4V rods were
manufactured in vertical, horizontal, and 45º angle orientations. The specimens were then
machined and polished along the gage section in order to reduce the effects of surface roughness
on fatigue behavior. Fully-reversed strain-controlled uniaxial fatigue tests were performed at
various strain amplitudes with frequencies adjusted to maintain an average constant strain rate
throughout testing. Results indicate slight variation in fatigue behavior of specimens fabricated in
the different orientations investigated. Fractography was conducted using scanning electron
microscopy after mechanical testing in order to investigate the crack initiation sites and determine
the defect responsible for the failure. The experimental program utilized and results obtained will
be presented and discussed.",,,,,,
"['Andurkar, M.', 'Prorok, B.C.', 'Thompson, S.M.']",2023-04-05T13:51:10Z,2023-04-05T13:51:10Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117774', 'http://dx.doi.org/10.26153/tsw/44653']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'Nickel Superalloy', 'EBSD', 'Misorientation', 'Microstrain']",Effect of Build Orientation on Residual Stress and Microstructure in Inconel 625 Fabricated via Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5844b908-74e8-4352-aa8f-d91f704a2e6c/download,,"The reliability of parts produced by Laser Powder Bed Fusion (L-PBF) is still not at a great 
acceptance level. One of the major defects inherited in parts fabricated from L-PBF is a high level 
of residual stress. In this study, two build orientations i.e., vertical and diagonal, were used to 
fabricate Inconel 625 specimens to observe its effects on the residual stress magnitude and grain 
growth. A novel, Cos-α X-ray diffraction method was used to measure residual stress values along 
the top surface of the samples. Electron Backscattered Diffraction (EBSD) and kernel average 
misorientation (KAM) maps were employed to explain residual stress trends and differences 
between samples. Results indicate that the as-printed vertical sample possessed a higher tensile 
residual stress (77 ± 15 MPa) compared to the diagonally-printed sample (52 ± 12 MPa). The KAM 
map of the as-printed vertically oriented sample showed more pronounced local misorientations 
caused by dislocations compared to the diagonally-printed sample.",,,,,,
"['Shrestha, Rakish', 'Simsiriwong, Jutima', 'Shamsaei, Nima', 'Thompson, Scott M.', 'Bian, Linkan']",2021-10-27T21:11:01Z,2021-10-27T21:11:01Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89615,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'tensile properties', 'fractography', 'build orientation', 'additive manufacturing']",Effect of Build Orientation on the Fatigue Behavior of Stainless Steel 316L Manufactured via a Laser-Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a0efbba-a915-4878-8fbc-4cf4038e9339/download,University of Texas at Austin,"n this study, the effects of build orientation on the mechanical properties and fatigue life
of stainless steel (SS) 316L, fabricated using the Laser-Powder Bed Fusion (L-PBF) additive
manufacturing (AM) process, were investigated under monotonic tensile and uniaxial strain-controlled fully-reversed (R = -1) cyclic loadings. Tensile tests were conducted at a strain rate of
0.001 s-1
, while fatigue tests were performed at strain amplitudes ranging from 0.1% to 0.4% at
various frequencies to have a nearly consistent average strain rate in all tests. The comparison
between the tensile properties of additively manufactured and wrought SS 316L revealed that L-PBF specimens exhibited higher yield and ultimate tensile stresses as compared to the wrought
specimen. In addition, the elongation to failure of the wrought specimen was similar to that of the
horizontally oriented specimen, while it was lower relative to specimens built in vertical and
diagonal directions. From the strain-life fatigue analysis, the diagonally oriented L-PBF specimens
generally exhibited lower fatigue strength as compared to vertical and horizontal specimens. The
fractography analysis revealed three major types of defects to be responsible for the crack initiation
and failure. These included (1) voids formed due to lack of fusion between the subsequent layers
and entrapped gas, (2) inclusions formed due to the partially melted powder particles, and (3) un-melted powder particles clustered near a void.",,,,,,
"['Mueller, J.', 'Shea, K.']",2021-10-21T15:22:40Z,2021-10-21T15:22:40Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89394,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'inkjet printing', 'build orientation']",The Effect of Build Orientation on the Mechanical Properties in Inkjet 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08945b59-d06e-497d-acbd-dfb3df1b0c5a/download,University of Texas at Austin,"It is known that part orientation plays an important role in 3D printing and especially in
inkjet 3D printing, where the layers are more distinct than in other processes. Despite many
investigations in this direction, previous research focused mainly on build orientations along the
three main axes X, Y and Z. For advanced purposes such as optimization, however, it is important
to know what happens in combined alignments between the main axes. The authors hypothesize
and show that the transition is not linear and that, despite prior studies, the weakest properties
are not found when the parts are aligned along the Z direction. The discovered effects can partially
be attributed to shear forces in the material, which act between the layers when the parts are not
aligned orthogonally to the main axes. To accurately characterize the three-dimensional space, the
mixture design method has successfully been introduced to the area of 3D printing and proven to
be an efficient tool that can also be used for other processes. With the results of this study,
designers and engineers are now able to analyze and predict part properties on a much higher
level than before.",,,,,,
"['Murr, L.E.', 'Gaytan, S.M.', 'Medina, F.', 'Martinez, E.', 'Hernandez, D.H.', 'Martinez, L.', 'Lopez, M.I.', 'Wicker, R.B.', 'Collins, S.']",2021-09-28T20:24:14Z,2021-09-28T20:24:14Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88174', 'http://dx.doi.org/10.26153/tsw/15115']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'electron beam melting', 'build defects', 'Ti-6Al-4V powder', 'microstructure-mechanical property', 'build examination']",Effect of Build Parameters and Build Geometries on Residual Microstructures and Mechanical Properties of Ti-6Al-4V Components Built by Electron Beam Melting (EBM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c69bcc2-7859-4b01-a387-63fdf9993c5b/download,University of Texas at Austin,"In this study, involving additive manufacturing (AM) using electron beam melting (EBM), we
have examined build defects which result from beam tripping, porosities (including unmelted or
unsintered zones) due to excursions from optimal build parameters (especially variations in melt
scan beam current and scan speed), and gas bubbles trapped in atomized Ti-6Al-4V starting
powder as well as recycled powder, and retained in the build. At optimized build conditions we
have also examined microstructure-mechanical property (hardness, tensile strength, and
elongation) variations for multiple rake building and multiple melt scans using optical
metallography and scanning and transmission electron microscopy (SEM and TEM). These
build variances cause cooling rate variances which promote α-phase growth and variations in
dislocation density, as well as α-to-α' (martensite) phase changes, all of which produce some
degree of mechanical property variations. These features (especially α-to-α' phase changes) are
notable on comparing solid builds in comparison with a variety of mesh arrays where strut
dimension and build-element complexities alter the cooling rates in a significant way. We
illustrate these microstructure variations with corresponding variations in microindentation
hardness measurements made directly on fine mesh (strut) structures. Finally, we have examined
Ti-6Al-4V powder chemistries and solid build chemistries which for single-pass melt scans at
optimized build conditions are shown to be relatively constant up to 40 cycles of powder reuse
with the exception of Al content which was reduced by 10 to 15% in solid builds at optimized
conditions. However, Al loss in solid builds approached 25% for multiple (2 and 3) melt scans,
while no changes in Ar gas-bubble density were observed with changes in α-phase (grain) width
which increased from 3 µm for a single melt scan to 4.5 and 6 µm for 2 and 3 melt scans,
respectively. Corresponding Rockwell C-scale (HRC) hardness varied from 37, 36, and 35,
respectively; with ultimate tensile strengths exceeding 1.2 GPa at elongations of 12% or higher
for this melt scan sequence.",,,,,,
"['Mason, L.', 'Leu, M.C.']",2021-11-30T21:28:45Z,2021-11-30T21:28:45Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90554', 'http://dx.doi.org/10.26153/tsw/17473']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['ABS', 'lattice structures', 'cell size', 'surface roughness', 'compressive properties', 'fused deposition modeling']",The Effect of Cell Size and Surface Roughness on the Compressive Properties of ABS Lattice Structures Fabricated by Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/594975b1-f92e-4e0e-98ad-ec6a15571bae/download,University of Texas at Austin,"Researchers looking to improve the surface roughness of acrylonitrile butadiene styrene
(ABS) parts fabricated by fused deposition modeling (FDM) have determined that acetone
smoothing not only achieves improved surface roughness but increases compressive strength as
well. However, the sensitivity of ABS parts to acetone smoothing has not been explored. In this
study we investigated FDM-fabricated ABS lattice structures of various cell sizes subjected to
cold acetone vapor smoothing to determine the combined effect of cell size and acetone
smoothing on the compressive properties of the lattice structures. The acetone-smoothed
specimens performed better than the as-built specimens in both compression modulus and
maximum load, and there was a decrease in those compressive properties with decreasing cell
size. The difference between as-built and acetone-smoothed specimens was found to increase
with decreasing cell size for the maximum load.",,,,,,
"['He, Haiyang', 'Pan, Yayue', 'Yu, Xiaoming']",2021-11-04T14:58:50Z,2021-11-04T14:58:50Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89978,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'projection stereolithography', 'surface texture', 'constrained surface']",Effect of Constrained Surface Texturing on Separation Force in Projection Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1bb203a-0571-4853-9cae-fd5dbf1657ec/download,University of Texas at Austin,"In projection stereolithography (SL) processes, the separation of a newly cured layer from
the constrained surface is a historical technical barrier and still greatly limits its printable size,
process reliability and print speed. This paper presents an approach to reduce the separation force
in projection stereolithography (SL) processes by texturing the constrained surface with radial
microgroove patterns. Separation forces with conventional smooth constrained surface and
textured surface are both modeled. The analytical model suggests that a proper design of micro
patterns of the constrained surface is capable of reducing separation forces greatly. Furthermore, a
projection SL testbed with online separation force monitoring unit is developed for experimental
study. Experimental results verified the effectiveness of micro surface textures in reducing
separation forces. Test cases also show that with the help of the proposed textured constrained
surface, parts with wide solid cross sections that could not be printed using conventional methods
were manufactured successfully. The influence of the textured constrained surface on the printed
parts’ surface roughness is studied, a grey scale projection approach is proposed to eliminate the
influence and improve the surface quality of printed parts. Hence, the presented methods can help
to improve the manufacturing capability of Projection SL processes.",,,,,,
"['Gong, Haijun', 'Rafi, Khalid', 'Starr, Thomas', 'Stucker, Brent']",2021-10-06T20:21:19Z,2021-10-06T20:21:19Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88432', 'http://dx.doi.org/10.26153/tsw/15369']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'part defects', 'fatigue performance', 'Ti-6Al-4V']",Effect of Defects on Fatigue Tests of As-Build Ti-6Al-4V Parts Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/81afac47-1c23-4946-b1f7-f28680e0210d/download,University of Texas at Austin,"Defects can be found in parts made using Selective Laser Melting (SLM) due to balling effects
and other types of localized irregularities. This study investigates how defects affect the fatigue
performance of Ti-6Al-4V samples in an SLM as-built surface finish condition. Fatigue samples
were built and heat treated for stress relief. In order to investigate the effect of defects, a series of
fatigue samples were designed with built-in cylindrical and double-conical defects. Tests were
carried out to correlate maximum stress to the number of cycles to failure. Optical and scanning
electron micrographs were utilized to compare and analyze crack initiation and propagation
characteristics. Based on the results, the influence of defects on fatigue properties is discussed.",,,,,,
"['Muhammad, Muztahid', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-25T18:40:43Z,2023-01-25T18:40:43Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117296', 'http://dx.doi.org/10.26153/tsw/44177']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Laser powder bed fusion (L-PBF/LB-PBF)', 'Ti-6Al-4V', 'Defects', 'Tensile properties']",Effect of Defects on the Mechanical Properties of Laser Powder Bed Fused Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67607c26-9a2d-48cd-84fb-d278f34e9646/download,,"Process-induced volumetric defects are inherent to additively manufactured parts. This study 
investigates the effect of volumetric defects on the tensile properties of the laser powder bed fused (L-
PBF) Ti-6Al-4V specimens fabricated with large variations in process parameters (a total of six sets of 
process parameters). Cylindrical rods of L-PBF Ti-6Al-4V specimens were stress-relieved before removal 
from plates and machined to tensile specimens. The defect distribution of specimens resulting from each 
set of process parameters was analyzed using a high-resolution X-ray computed tomography machine. 
Quasi-static tensile tests were performed at room temperature using a servo-hydraulic MTS machine. 
Tensile results were correlated with defect statistics. No apparent difference was observed in the yield 
strength of the L-PBF Ti-6Al-4V specimens despite the large variations in the process parameters resulting 
in significant differences in defect content. However, a considerable drop in ductility was observed for the 
specimens fabricated with insufficient energy.",,,,,,
"['Guo, Nannan', 'Leu, Ming C.']",2021-09-30T18:30:46Z,2021-09-30T18:30:46Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88272', 'http://dx.doi.org/10.26153/tsw/15213']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['graphite materials', 'bipolar plates', 'Proton Exchange Membrane', 'Selective Laser Sintering', 'layer-by-layer manufacturing', 'complex gas flow channels', 'electrical conductivity', 'flexural strength']",Effect of Different Graphite Materials on Electrical Conductivity and Flexural Strength of Bipolar Plates Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7324bb24-8b98-4583-9b83-1c7d43b10eec/download,University of Texas at Austin,"Graphite is an excellent material for bipolar plates used in Proton Exchange Membrane (PEM)
fuel cell due to its great chemical resistance, but the brittle nature makes it difficult to
manufacture. Selective Laser Sintering (SLS) based on layer-by-layer manufacturing technology
can fabricate graphite bipolar plates with complex gas flow channels. To improve the
performance of bipolar plates including electrical conductivity and flexural strength, different
graphite materials (natural graphite, synthetic graphite, carbon black, and carbon fiber) were
investigated to fabricate test samples. These samples then went through post processing
including carbonization and infiltration. The results show that bipolar plates with electrical
conductivity of 380 S/cm and flexural strength of 40 MPa are obtained from proper combinations
of natural graphite and carbon fiber, which are higher than the target values set by the
Department of Energy.",,,,,,
"['Olakanmi, E.O.', 'Sepako, M.', 'Morake, J.', 'Kutua, S.', 'Hoosain, S.E.', 'Pityana, S.L.']",2021-11-11T15:22:48Z,2021-11-11T15:22:48Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90218', 'http://dx.doi.org/10.26153/tsw/17139']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['functionally graded materials', 'FGM', 'laser cladding', 'LC', 'chemical composition', 'titanium aluminide', 'Ti-Al']",Effect of Energy Density on the Consolidation Mechanism and Microstructural Evolution of Laser Cladded Functionally-Graded Composite Ti-Al System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83d74bdf-5bc9-409c-bbb8-5aefcfd07c78/download,University of Texas at Austin,"The engagement of additive manufacturing (AM) technology in developing
intermetallic coatings involves additional heat treatment with a view to obtaining desirable
microstructure and mechanical properties. This eventually increases the lead time and the
manufacturing cost. To address these challenges, this study explores the fabrication of gradient
and laminar structures of titanium aluminide (Ti-Al) composite coatings deposited on Ti-6Al-4V
substrate via a single step laser cladding (LC). The alterations in microstructural properties,
chemical composition and phase analysis of the coatings reinforced with TiC were investigated as
a function of laser energy density. Evaluation of the deposited samples reveals that FGM
composite clads were fabricated from Ti-Al blended with TiC when LED was set at 17.50 J/mm2
.
At the selected LED, a thermo-positive reaction between the constituents’ materials was induced
and it resulted in the formation of intermetallic compounds (e.g. Ti2AlC, 𝛾𝛾 and 𝛼𝛼2 matrix phases)
with a microhardness more than that of the substrate (Ti-6Al-4V alloy). This study provides new
insights on the selection of process parameters for the coating manufacturers while employing low
cost- and time-effective LC process for fabricating functional graded Ti-Al coatings.",,,,,,
"['Flood, Aaron', 'Liou, Frank']",2021-11-15T20:53:36Z,2021-11-15T20:53:36Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90268', 'http://dx.doi.org/10.26153/tsw/17189']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['environmental factors', 'simulation', 'Ti-64', 'metal additive manufacturing']",Effect of Environmental Variables on Ti-64 AM Simulation Results,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4349941-6dfc-443a-8f2a-0eb8aa46fee7/download,University of Texas at Austin,"In metal AM the environment is critical and therefore care should be taken to ensure that
the simulation matches reality. This paper will investigate the effect that various environmental
factors have on the results of the simulation. This will help to determine their importance in
the simulation setup. The material properties which relate to this are the convective coefficient
and the emissivity. These material properties will be investigated to determine their effect on
the outcome of the simulation. In addition to these properties, the size of the substrate will
be investigated to determine if any results are altered. Lastly, the ambient temperature will be
investigated to determine the effect this has on the simulation results.",,,,,,
"['Heller, B.P.', 'Smith, D.E.', 'Jack, D.A.']",2021-10-21T18:03:54Z,2021-10-21T18:03:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89413,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'nozzle flow', 'melt flow', 'fiber orientation', 'convergence zone', 'extrudate swell', 'nozzle exit shape']","Effect of Extrudate Swell, Nozzle Shape, and Convergence Zone on Fiber Orientation in Fused Deposition Modeling Nozzle Flow",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4249cf2-9dd3-49c8-b5a2-4b600b901a6d/download,University of Texas at Austin,"Recent advances for improving the mechanical properties of materials used in Fused
Deposition Modeling (FDM) include the addition of carbon fibers to the filament feedstock.
During processing, the flow field within the polymer melt orients the fiber suspension, which is
important to quantify since fiber orientation influences mechanical and thermal properties. This
paper presents a computational approach for evaluating polymer melt flow and fiber orientation
within a FDM nozzle taking into consideration the converging flow in the nozzle, fluid
expansion caused by extrudate swell, and nozzle exit shape. Finite elements are used to evaluate
the Stoke’s flow in an axisymmetric nozzle and fiber orientation tensors are evaluated along
streamlines within the flow using the Fast Exact Closure and Folgar-Tucker isotropic rotary
diffusion. Fiber orientation is shown to increase in the shear-dominated flow through the nozzle,
however, alignment is found to decrease in the expansion flow of the die swell.",,,,,,
"['Davis, Joy E.', 'Klingbeil, Nathan W.']",2021-09-30T14:00:17Z,2021-09-30T14:00:17Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88253', 'http://dx.doi.org/10.26153/tsw/15194']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['laser beam-based fabrication', 'electron beam-based fabrication', 'additive manufacturing', 'repair applications', 'melt pool geometry', 'microstructure solidification', '3-D structures']",Effect of Free-Edges on Melt Pool Geometry and Solidification Microstructure in Beam-Based Fabrication of Bulky 3-D Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c374c9dc-e6e7-4aec-b726-6393b8ae6a1e/download,University of Texas at Austin,"The success of laser and electron beam-based fabrication processes for additive manufacture
and repair applications requires the ability to control melt pool geometry while still maintaining a
consistent and desirable microstructure. To this end, previous work by the authors has employed
point heat source solutions to investigate the effects of process variables (beam power and velocity)
on melt pool geometry and solidification microstructure (grain size and morphology) in beam-based fabrication of bulky 3-D structures. However, these results were limited to steady-state
conditions away from free-edges. The current work extends the approach to investigate transient
behavior in the vicinity of free-edges, and follows the authors’ recent work for 2-D thin-wall
geometries [1].",,,,,,
"['Noble, Christopher James', 'Ellis, Adam', 'Hopkinson, Neil']",2021-10-12T20:42:54Z,2021-10-12T20:42:54Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88736', 'http://dx.doi.org/10.26153/tsw/15670']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['High Speed Sintering', 'Additive Manufacturing', 'ink dosage', 'greyscale', 'part density']",Effect of Greyscale/Print Density on the Properties of High Speed Sintered Nylon 12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93b126e0-08ae-4581-ad59-6e7765eff171/download,University of Texas at Austin,"High Speed Sintering is an Additive Manufacturing process that creates parts by sintering
using inkjet and infra-red lamp technology, rather than the laser systems employed in Laser
Sintering. This research investigated the effects of altering the dosage of ink (greyscale/print
density) on the properties of parts produced. A clear pattern emerges that shows a ‘sweet spot’ for
correct dosage of ink to maximise properties. The work also shows that greyscale allows
considerable control of part density that could lead to substantial reductions in part mass beyond
those that may be achieved by conventional design optimisation approaches employed today.",,,,,,
"['Zhang, Bin', 'Ham, Kyungmin', 'Shao, Shuai', 'Shamsaei, Nima', 'Thompson, Scott M.']",2021-11-02T13:55:09Z,2021-11-02T13:55:09Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89803,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['heat treatment', 'hot isostatic pressing', 'Ti-6Al-4V', 'laser-based powder bed fusion', 'morphology', 'pore size', 'porosity']",Effect of Heat Treatment and Hot Isostatic Pressing on the Morphology and Size of Pores in Additive Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7f21d306-495d-46e3-8de7-e6c345474a7c/download,University of Texas at Austin,"Additive manufactured parts suffer from porosity, among other defects. The slit-shaped
pores due to lack of fusion are the most detrimental to fatigue and mechanical properties. Their
sharp edges generate severe stress concentration and serve as preferred sites for crack initiation.
The sharp edges also have low formation energy of surface adatoms, increasing their tendency to
spheroidize under elevated temperatures, such as during heat treatment (HT). In hot isostatic
pressing (HIP), the combined action of high temperature/pressure also reduces the size of the
pores. In this work, HT and HIP were performed on Ti-6Al-4V parts manufactured from laser-based powder bed fusion to investigate the effect of HT and HIP on morphology/size of pores.
Using scanning electron microscopy combined with X-ray computed tomography, special
attention is paid to the evolution of the shape of the pore1s under controlled exposures to elevated
temperature during HT. The results will be used, in our subsequent work, to validate a phase field
porosity evolution model based on density functional theory.",,,,,,
"['Montero Sistiaga, M.L.', 'Nardone, S.', 'Hautfenne, C.', 'Van Humbeeck, J.']",2021-10-26T20:24:42Z,2021-10-26T20:24:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89577,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'additive manufacturing', '316L', 'heat treatment']",Effect of Heat Treatment of 316L Stainless Steel Produced by Selective Laser Melting (SLM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa96c87e-d1b1-4afc-b22d-b7cfcc564aad/download,University of Texas at Austin,"Selective Laser Melting (SLM) shows a big potential within additive manufacturing of
metals. The competitive mechanical properties compared to conventional processes as well as the
geometry freedom are the main advantages of SLM. 316L stainless steel has been investigated in
previous works regarding microstructure and mechanical properties. However, the influence of
heat treatments has not been fully reported yet. This work studies the influence of different heat
treatments applied to 316L stainless steel produced by SLM. The microstructure evolution was
investigated for different conditions. Tensile, Charpy and hardness tests were performed on the as
built and heat treated samples.",,,,,,
"['Nandi, Indrajit', 'Ghiaasiaan, Reza', 'Ahmad, Nabeel', 'Gradl, Paul R.', 'Shamsaei, Nima']",2024-03-25T23:36:30Z,2024-03-25T23:36:30Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124339', 'https://doi.org/10.26153/tsw/50947']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Monel K500', 'Ni-base superalloys', 'microstructure', 'tensile properties']",Effect of heat treatment on the microstructure and mechanical properties of Monel K500 alloy fabricated via L-PBF and LP-DED,Conference paper,https://repositories.lib.utexas.edu//bitstreams/80a961c1-a24a-43c7-a433-3696372ed16c/download,University of Texas at Austin,"This study examines and compares the effect of different heat treatments (HT) on the microstructure
and mechanical properties of Monel K500 fabricated using laser powder bed fusion (L-PBF) and laser
powder directed energy deposition (LP-DED) technologies. The as-fabricated Monel K500 specimens
exhibited dendritic microstructure and elemental micro-segregation due to high cooling rates induced during
the fabrication process. The applicability of HT proposed in the literature for wrought Monel K500 was
investigated for L-PBF and LP-DED using four different HT procedures involving hot isostatic pressing
(HIP), solution annealing (SA), and aging. The mechanical properties of test specimens were evaluated
using uniaxial tensile testing at room temperature. The microstructural evolution of test specimens during
HT was analyzed using a scanning electron microscope. For all HT conditions investigated, L-PBF Monel
K500 specimens consistently displayed higher strength and lower ductility compared to the LP-DED
counterparts. The HT procedure involving HIP at 1160°C for 3hr at 100 MPa, SA at 1100°C for 15 min, and
three step aging at 610°C for 16 hr, 540°C for 6 hr, and 480°C for 8 hr resulted in highest strength for both
L-PBF and LP-DED fabricated Monel K500.",,,,,,
"['Baig, Shaharyar', 'Shao, Shuai', 'Gradl, Paul R.', 'Shamsaei, Nima']",2023-01-25T18:32:11Z,2023-01-25T18:32:11Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117295', 'http://dx.doi.org/10.26153/tsw/44176']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing (AM)', 'laser powder bed fusion (L-PBF)', 'Haynes 214', 'microstructure', 'tensile properties']",The Effect of Heat Treatment on the Microstructure and Tensile Properties of Laser Powder Bed Fused (L-PBF),Conference paper,https://repositories.lib.utexas.edu//bitstreams/114f6dee-e90c-45cc-8a87-04326193fa2f/download,,"The as-fabricated microstructure of Haynes 214 by laser powder bed fusion (L-PBF) is dendritic 
due to the high cooling rates, which is generally considered undesirable and removed via heat 
treatments. In this study, the effects of various heat treatments on the microstructure and tensile 
properties of laser powder bed fused Haynes 214 are investigated. Test specimens were fabricated 
on a L-PBF system in the vertical orientation. Multi-step heat treatments were performed including 
stress-relief, hot isostatic pressing, solution annealing and ageing. Examining the microstructures 
revealed columnar grains in the non-heat treated (NHT) condition with grain growth occurring 
after stress relief. Room temperature tensile tests showed the lowest strengths in the NHT 
condition. The highest strengths were seen in the aged condition which was attributed to gamma 
prime precipitation hardening. Finally, the tensile fracture surfaces indicated ductile failure mode 
in both the NHT and heat treated conditions with the measured elongation being the highest for 
NHT and lowest in the aged condition.",,,,,,
"['Basak, Amrita', 'Das, Suman']",2021-11-02T14:37:56Z,2021-11-02T14:37:56Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89812,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'scanning laser epitaxy', 'SLE', 'nickel-base', 'superalloys', 'CMSX-4', 'heat treatment']",Effect of Heat Treatment on the Microstructures of CMSX-4® Processed Through Scanning Laser Epitaxy (SLE),Conference paper,https://repositories.lib.utexas.edu//bitstreams/91f48016-61b0-4976-a43e-2cf27ce44840/download,University of Texas at Austin,"Engineered components made of superalloys routinely undergo heat treatment procedures
to tailor their microstructures and properties. In this study, the effect of heat treatment on the
microstructures and microhardness of single-crystal nickel-base superalloy CMSX-4® is
investigated. Samples of CMSX-4® are fabricated using scanning laser epitaxy (SLE), a laser
powder bed fusion (LPBF)-based additive manufacturing process. Microstructural
characterizations of the as-deposited and the heat treated CMSX-4® samples are performed using
optical microscopy, scanning electron microscopy, x-ray diffraction, and Vickers microhardness
measurements. The results show that the microstructure is homogenized with reductions in the
eutectic volume fraction after heat treatment. The microhardness values are also improved upon
heat treatment.","This work is sponsored by the Office of Naval Research through grant N00014-14-
1-0658.",,,,,
"['Nezhadfar, P.D.', 'Verquin, Benoit', 'Lefebvre, Fabien', 'Reynaud, Christophe', 'Robert, Maxime', 'Shamsaei, Nima']",2021-12-06T22:09:33Z,2021-12-06T22:09:33Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90692', 'http://dx.doi.org/10.26153/tsw/17611']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['metal binder jetting (MBJ)', 'stainless steel', 'microstructure', 'heat treatment', 'tensile']",Effect of Heat Treatment on the Tensile Behavior of 17-4 PH Stainless Steel Additively Manufactured by Metal Binder Jetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db0a8a75-44d6-476e-bff9-d04007659344/download,University of Texas at Austin,"Metal Binder Jetting (MBJ), a non-fusion-based powder bed additive manufacturing (AM)
process, enables the fabrication of complex geometries with minimum residual stresses. Various
materials have been successfully manufactured via the MBJ process; however, appropriate post-process heat treatments are required to enhance their mechanical performance as compared to the
wrought or other additively manufactured counterparts. This study aims to investigate the effect
of post-manufacture heat treatment on the microstructure and mechanical properties of MBJ 17-4
PH stainless steel (SS). Various heat treatment procedures following the standard routes for the
wrought 17-4 PH SS are conducted to evaluate their effects on the tensile behavior of MBJ 17-4
PH SS. The mechanical behavior of the MBJ 17-4 PH SS in various heat treatment conditions is
discussed based on their corresponding microstructure.",,,,,,
"['Gusain, Rukesh', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2024-03-25T23:39:04Z,2024-03-25T23:39:04Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124340', 'https://doi.org/10.26153/tsw/50948']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['LP-DED', 'precipitation hardened stainless steel', 'heat treatment effects', 'cryogenic temperature', 'tensile fracture']",EFFECT OF HEAT TREATMENTS ON THE TENSILE PROPERTIES OF ADDITIVELY MANUFACTURED 15-5 PH STAINLESS STEEL,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90bbabca-5fb3-4592-ad0e-126b1c69e900/download,University of Texas at Austin,"This study investigated the effect of post-manufacture heat treatments on the microstructure and
mechanical properties of 15-5 PH stainless steel (SS) fabricated by laser powder-directed energy deposition (LPDED). Various heat treatment procedures (CA-H900 and CA-H1150) were conducted to evaluate their effects on the
tensile behavior of LP-DED 15-5 PH SS. Scanning electron microscopy was used to characterize the
microstructural features and the fracture surfaces. Tensile tests were performed to evaluate the mechanical
properties at cryogenic and room temperatures. The mechanical behavior of the LP-DED 15-5 PH SS in different
heat treatment conditions is discussed based on their microstructures and fracture surfaces. Reduction in area of
CA-H1150 treated specimens after tensile tests was significantly higher than CA-H900 ones, while the ultimate
tensile and yield strengths of CA-H900 specimens were higher compared to the CA-H1150 ones. The CA-H1150
specimens had relatively coarser Cu-enriched precipitates, and exhibited greater necking compared to CA-H900
specimens.",,,,,,
"['Leigh, David K.', 'Bourell, David L.', 'Beaman, Joseph J. Jr']",2021-10-05T13:34:52Z,2021-10-05T13:34:52Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88368', 'http://dx.doi.org/10.26153/tsw/15307']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'rapid', 'polyamide', 'Selective Laser Sintering']",Effect of In-Plane Voiding on the Fracture Behavior of Laser Sintered Polyamide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0cd74f16-8881-4b64-90f8-b8cd4071bbe5/download,University of Texas at Austin,"The primary contributors to poor mechanical properties in polyamide materials used during Selective
Laser Sintering® are qualified. Methods to quantify the decreased mechanical properties, including
Scanning Electron Microscopy (SEM) of fracture surfaces, are compared against each other and against
mechanical properties of components fabricated using multiple process parameters. Of primary interest
are Ultimate Tensile Strength (UTS) and Elongation at Break (EOB) of tensile specimens fabricated
under conditions that produce varying degrees of ductile and brittle fracture.",,,,,,
"['Beyene, Shiferaw D.', 'Ayalew, Beshah', 'Pilla, Srikanth']",2021-11-10T22:30:36Z,2021-11-10T22:30:36Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90193', 'http://dx.doi.org/10.26153/tsw/17114']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['in-situ compaction', 'UV-induced curing', 'layer-by-layer', 'curing', 'glass fiber', 'fiber-reinforced polymer']",Effect of In-Situ Compaction and UV-Curing on the Performance of Glass Fiber-Reinforced Polymer Composite Cured Layer by Layer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c484095a-f6ff-425d-adb1-1beaa05bec05/download,University of Texas at Austin,"In this paper, the effect of in-situ compaction and UV-induced curing on the performance of
fiber-reinforced diglycidyl ether bisphenol A (DGEBA) based epoxy is studied for a layer-by-layer
curing process. The optimum percentage of photo-initiator concentration and UV-intensity were
obtained by conducting a different experiment for each of them. Fourier Transform Infrared
(FTIR) spectroscopy method is used to determine the degree of cure. Then, short beam shear (SBS)
test is conducted to measure the inter-laminar shear strength of the cured product under different
compaction load. The UV intensity and Photo-initiator concentration were kept constant during
the test. The result showed that thick composite parts fabricated with in-situ compaction and UV
curing process have showed increased inter-laminar shear strength with increased compaction load
up to a certain point. An increase in compaction beyond this point decreased the interlaminar-shear
strength.",,,,,,
"['Kishore, Vidya', 'Nycz, Andrzej', 'Lindahl, John', 'Duty, Chad', 'Carnal, Charles', 'Kunc, Vlastimil']",2021-11-18T18:38:23Z,2021-11-18T18:38:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90461', 'http://dx.doi.org/10.26153/tsw/17382']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['infrared preheating', 'mechanical properties', 'z-direction', 'anisotropy', '3D printed parts', 'large-format extrusion additive manufacturing']",Effect of Infrared Preheating on the Mechanical Properties of Large Format 3D Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53183dcf-bf2e-43a5-ad13-63d3288e6b31/download,University of Texas at Austin,"Anisotropy of mechanical properties is characteristic of components printed using processes
like extrusion deposition additive manufacturing, wherein the properties along the print direction
(x-direction) are superior when compared to the corresponding properties in the build direction (z-direction). This effect, influenced by the bond strength in the z-direction, can be more pronounced
for components with longer layer times, as the bottom layers tend cool below the glass transition
temperature (Tg) of the material, thereby restricting thermal fusion between the printed layers. The
work discussed here builds on the previous work by the authors, demonstrating infrared preheating
as a technique to actively control the bond temperature during printing to improve the mechanical
properties (z-direction) of parts printed on a large-format extrusion AM system. IR preheating was
used on the surface of printed layers just prior to the deposition of the next layer to increase the
surface temperature closer to the glass transition temperature. The current study explores the effect
of variation in bead surface temperatures (indicative of variations in layer times) prior to and after
pre-heating on the mechanical properties in z-direction.",,,,,,
"['Bandari, Y.K.', 'Lee, Y.S.', 'Nandwana, P.', 'Richardson, B.S.', 'Adediran, A.I.', 'Love, L.J.']",2021-11-09T16:39:11Z,2021-11-09T16:39:11Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90109', 'http://dx.doi.org/10.26153/tsw/17030']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive layered manufacturing', '3-D printing', 'direct energy deposition', 'laser metal deposition with wire', 'Ti-6Al-4V', 'laser scanner', 'distortion', 'residual stress']",Effect of Inter-Layer Cooling Time on Distortion and Mechanical Properties in Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/21cc7076-ab8f-4f31-b371-372e5bcd4662/download,University of Texas at Austin,"Laser Metal Deposition with wire (LMD-w) is one of the novel Direct Energy Deposition
(DED) processes that is gaining the attention of various industries, especially aerospace, due to the
potential cost and lead time reductions for complex parts. However, subjects of development
include optimization of process parameters (for example laser power, wire feed speed, robotic
travel speed, inter-layer cooling time etc.) for large scale adaption of this process. These
parameters influence residual stress which potentially results in distortion and subsequent
mechanical properties. Inter-layer cooling time is one of the main influences on production volume
and is typically used to help control the cooling conditions to mitigate part distortion. Therefore,
this paper is aimed at investigating different inter-layer cooling times on distortion and resulting
mechanical properties of the parts produced by LMD-w. Distortion of deposited Ti-6Al-4V walls
was measured automatically using a laser scanner, which was attached to the robotic arm itself.
Finally, suitable recommendations are discussed to optimize the inter-layer cooling time to
produce parts with desired mechanical properties.",,,,,,
"['Joy, Ranjit', 'Wu, Sung-Heng', 'Tariq, Usman', 'Mahmood, Muhammad Arif', 'Liou, Frank']",2024-03-27T03:52:30Z,2024-03-27T03:52:30Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124477', 'https://doi.org/10.26153/tsw/51085']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'residual stress', 'inter-layer dwell time', 'high strength steel alloy']",Effect Of Inter-Layer Dwell Time on Residual Stresses in Directed Energy Deposition of  High Strength Steel Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/125a716d-b4fe-40d0-922c-860abe98abeb/download,University of Texas at Austin,"Adoption of metal additive manufacturing by various industries is being hindered by the presence of
residual stresses and distortion in the deposited parts. Large thermal gradients during directed energy deposition
often led to residual stresses in the final deposit. Parameter optimization is predominantly used for residual
stress mitigation. However, the effect of process parameters is material specific. Current research aims to study
the effect of inter-layer dwell time on residual stresses in directed energy deposition of high strength steel alloy.
Specimens were deposited at three levels of inter-layer dwell time. Surface as well as bulk residual stresses
were measured using X-ray diffraction. Both surface as well as bulk residual stresses were found to increase
with an increase in the inter-layer dwell time.",,,,,,
"['Torries, Brian', 'Shao, Shuai', 'Shamsaei, Nima', 'Thompson, Scott M.']",2021-10-28T19:11:55Z,2021-10-28T19:11:55Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89672,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'fractography', 'tensile properties', 'microstructure', 'geometry effects']",Effect of Inter-Layer Time Interval on the Mechanical Behavior of Direct Laser Deposited Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2589182d-f6d3-4d40-8cad-dc9787b8c450/download,University of Texas at Austin,"Due to its wide applicability in the biomedical and aerospace fields, where unique and/or
difficult to machine geometries are required, Ti-6Al-4V continues to be a strong candidate for
additive manufacturing. In this study, the effect of inter-layer time interval on the mechanical
behavior of Ti-6Al-4V fabricated via Laser Engineered Net Shaping (LENSTM) is investigated.
Two sets of specimens were fabricated, each with their own inter-layer time interval, accomplished
by depositing either one or two specimens per operation. Tensile tests and fully reversed, strain
controlled fatigue tests were conducted on the specimens. Experimental results indicate that
specimens fabricated using longer inter-layer time intervals possess a higher ultimate tensile
strength, lower ductility, and finer microstructure relative to those fabricated using shorter time
intervals. Additionally, specimens fabricated using longer inter-layer time intervals possessed
shorter fatigue lives due to presence of more process defects, such as pores and lack of fusion,
inherent to additive manufacturing. Such effects are important to consider when producing multi-part assemblies or large parts.",,,,,,
"['Rafique, Muhammad Musaddique Ali', 'Brandt, Milan', 'Easton, Mark', 'Qiu, Dong', 'Cole, Ivan', 'John, Sabu']",2021-11-10T21:21:30Z,2021-11-10T21:21:30Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90179', 'http://dx.doi.org/10.26153/tsw/17100']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive', 'bulk metallic glass', 'composites', 'inoculation', 'phase']",Effect of Laser Additive Manufacturing of Microstructure Evolution of Inoculated Zr47.5Cu45.5Al5Co2 Bulk Metallic Glass Matrix Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02ef9a5d-503d-4050-8620-ee3d4edecd92/download,University of Texas at Austin,"Bulk metallic glass matrix composites are advocated to be material of future owing to their superior
strength, hardness and elastic strain limit. However, they possess poor toughness which makes
them unusable in any structural engineering application. Inoculation has been used as an effective
means to overcome this problem. Zr47.5Cu45.5Al5Co2 bulk metallic glass matrix composites
(BMGMC) inoculated with ZrC have shown considerable refinement in microstructure owing to
heterogeneous nucleation. Efforts have also been made to exploit modern laser-based metal
additive manufacturing to fabricate BMGMC parts in one step. However, the effect of laser
treatment on inoculated material is unknown. In this study, an effort has been made to apply laser
based additive manufacturing on untreated and inoculated BMGMC samples. It is observed that
laser treatment not only refined the microstructure but resulted in change of size, morphology and
dispersion of CuZr B2 phase in base metal, heat affected zone and fusion zone. This effect is
documented with back scattered electron imaging. This provides a basis for further research to
quantify this phenomenon and full-scale part development.",,,,,,
"['Lin, Yafu', 'Huang, Guohui', 'Huang, Yong', 'Tzeng, Jeremy', 'Chrisey, Douglas']",2021-09-29T17:38:16Z,2021-09-29T17:38:16Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88198', 'http://dx.doi.org/10.26153/tsw/15139']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Matrix-Assisted Pulsed-Laser Evaporation Direct-Write', 'laser fluence', 'cell viability']",Effect of Laser Fluence in Laser-Assisted Direct Writing of Human Colon Cell,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d6a7d316-4344-4ccf-9eff-fed82fee5862/download,University of Texas at Austin,"Matrix-Assisted Pulsed-Laser Evaporation Direct-Write (MAPLE DW) has been emerging as a
promising biological construct fabrication technique. The post-transfer cell viability in MAPLE
DW depends on various operation conditions such as the applied laser fluence. For wide
implementation of MAPLE DW-based biofabrication, the effect of laser fluence on the
post-transfer cell viability should be first carefully understood. This study investigates the effect
of laser fluence on the post-transfer cell viability in transferring of human colon cell HT-29. It
has been observed that: 1) the HT-29 cell viability decreases from 95% to 78% as the laser
fluence increases from 258 to 1,500 mJ/cm²; and 2) cell injury in this study is mainly from the
process-induced mechanical stress during the cell droplet formation and cell landing processes
while the effects of thermal influence and ultraviolet radiation are below the level of detection.",,,,,,
"['Lee, Seungjong', 'Bureš, Martin', 'Shao, Shuai', 'Wells, Douglas N.', 'Zetek, Miroslav', 'Kepka, Miloslav', 'Shamsaei, Nima']",2023-01-25T18:14:30Z,2023-01-25T18:14:30Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117292', 'http://dx.doi.org/10.26153/tsw/44173']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Inconel 718', 'Laser powder bed fusion', 'Laser-polishing', 'Surface roughness', 'Fatigue']",Effect of laser polishing on fatigue behavior of additively manufactured IN718,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3ec1a720-0619-4ce4-bdfc-badfbab4fdf1/download,,"This study investigates the effect of laser-polishing on the fatigue behavior of Inconel 718 
fabricated using laser powder bed fusion process. Three different conditions including as-built and 
laser-polished using two different process parameters are considered. Uniaxial tension-
compression fatigue tests are conducted in strain-controlled mode to examine the fatigue behavior 
for each condition. In addition, surface roughness measurements and fractography using optical 
microscopy and porosity measurements using the X-ray computed tomography are also performed 
for all conditions. The results indicate that laser-polishing alone does not improve fatigue 
performance, even though it can significantly reduce surface roughness. The beneficial effects of 
the smoother surfaces may have been countered by the volumetric defects close to the surface 
induced by laser-polishing. The fracture surfaces also reveal that fatigue cracks are initiated from 
the defects close to the surface, and therefore, fatigue behavior is not improved.",,,,,,
"['Layton, Andrew C.', 'Rosen, David W.']",2019-11-20T16:41:33Z,2019-11-20T16:41:33Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78479', 'http://dx.doi.org/10.26153/tsw/5564']",,2003 International Solid Freeform Fabrication Symposium,Open,Layer Orientation,The Effect of Layer Orientation on the Tensile Properties of Net Shape Parts Fabricated in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3388b601-a3f6-4973-b2c8-fc4a3ede5454/download,,"Stereolithographic technologies create parts in thermoset plastic polymeric mixtures of
acrylates and epoxies. In order to predict the mechanical behavior of these parts, it is critical to
understand the effects that build parameters have on the final properties of the polymer. Using a
statistics based approach, the build parameters of layer orientation, layer thickness, and resin
class are used as inputs. The response variables, peak stress, elongation at break and Young’s
modulus (modulus of elasticity), are examined using the methodology specified in ASTM D638-
01 with modifications as noted. An initial test in Somos 8120 showed the surprising (and
statistically significant) result that load bearing capability in the build direction was greater than
in the in-layer direction. Additional tensile tests in Somos 8120 and Vantico SL-5510 were
undertaken to verify this result, and determine if this effect is present across different classes of
resin. This report details the rationale behind this experiment, presents the results to date, and
outlines future efforts.",,,,,,
"['Majewski, Candice', 'Hopkinson, Neil']",2019-10-22T18:01:59Z,2019-10-22T18:01:59Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76328', 'http://dx.doi.org/10.26153/tsw/3417']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Ejection,The Effect of Layer Thickness on Ejection Forces for Injection Moulded Parts Made Using DMLS Tools,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9c327a5-90af-402f-a78c-5c14969823f8/download,,"Direct metal laser sintered (DMLS) parts have previously been shown to be suitable for
some tooling applications, in particular for injection moulding of plastics. This work shows that
recent developments in materials have increased the suitability of DMLS tools for injection
moulding processes, in terms of the force required to eject a part from a tool.
Tools were manufactured for testing from two bronze (DirectMetal 50 and DirectMetal
20) and two steel (DirectSteel 50 and DirectSteel 20) powders, and the forces required to eject
ABS parts from these tools were recorded. It can be seen that the more recent powder
developments, sintered in 20 µm layers, showed a dramatic improvement over the older powders,
sintered in 50 µm layers.",,,,,,
"['Fitzgerald, E.', 'Everhart, W.']",2021-10-26T20:28:42Z,2021-10-26T20:28:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89579,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', '316L', 'build location', 'tensile properties']",The Effect of Location on the Structure and Mechanical Properties of Selective Laser Melted 316L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/07ea44f5-1254-4dd1-9cad-33dd2c6657d6/download,University of Texas at Austin,,,,,,,
"['Yuksel, Anil', 'Cullinan, Michael', 'Murthy, Jayathi']",2021-10-26T19:05:48Z,2021-10-26T19:05:48Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89559,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['nanotechnology', 'surface plasmon polaritons', 'near-field energy enhancement']",The Effect of Nanoparticle Clustering on Optoelectronic Property,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47b18a19-33bc-4b16-9be6-3d21af6f25d2/download,University of Texas at Austin,"Metal nanoparticles have been extensively investigated for the applications in micro-nano electronics,
plasmonics, and chip packaging due to their enhanced thermal, mechanical and electrical properties at the nanoscale.
For instance, surface-to-volume ratio and particle distribution significantly affect the sintering and melting behavior of
nanoparticles relative to bulk properties. Hence, understanding the characteristic behavior of these materials is vital for
the use of these nanoparticles in existing and new applications. It has been shown that at the nanoscale van der Waals
forces are the dominant force between particles, which results in particle agglomeration and creates particle clustering.
In this paper, we show how this nanoparticle clustering effects the optoelectronic property of the domain by applying
the finite difference frequency domain method. This is the first step towards understanding the modeling of the heat
transfer that characterizes the laser particle interaction for additive manufacturing using nanoparticles.",,,,,,
"['Li, W.', 'Zhang, J.W.', 'Zhang, X.C.', 'Karnati, S.', 'Liou, F.']",2021-11-02T14:50:05Z,2021-11-02T14:50:05Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89816,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['functionally gradient material', 'pre-mixed multi-powder', 'laser metal deposition', 'powder separation', 'composition deviation']",Effect of Optimizing Particle Size in Laser Metal Deposition with Blown Pre-Mixed Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78dbfdc1-b00c-4474-9dfb-b14f13fe19ff/download,University of Texas at Austin,"Functionally Graded Material (FGM) is often fabricated by Laser metal deposition with
pre-mixed multiple powders (PMM-powder). Since the supplied PMM-powder directly affects
FGM’s composition, investigation on PMM-powder’s property is greatly needed. This paper
employed experimental method to observe an important problem: PMM-powder separation in
fabricating FGM. A novel particle size optimization method was introduced as solution to
eliminate the powder separation. Pre-mixed pure Cu and 4047 Al powders were used to do two
experiments. The first experiment result disclosed the existence of powder separation. By
optimizing the particle size, the PMM-powder separation was effectively solved in the second
experiment result.",,,,,,
"['Gomez Bonilla, Juan S.', 'Kletcher, Robin', 'Lanyi, Franz', 'Schubert, Dirk W.', 'Bück, Andreas', 'Schmidt, Jochen', 'Peukert, Wolfgang']",2021-11-18T01:34:20Z,2021-11-18T01:34:20Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90394', 'http://dx.doi.org/10.26153/tsw/17315']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['particle rounding', 'direct heating', 'optimized geometry', 'processability', 'polypropylene', 'selective laser sintering']",Effect of Particle Rounding on the Processability of Polypropylene Powder and the Mechanical Properties of Selective Laser Sintering Produced Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a135664f-d79c-498f-a45c-3c5b9bea1ad1/download,University of Texas at Austin,"Common techniques for the production of polymer powders for selective laser sintering (SLS) involve the
comminution of polymers. Comminution of polymers often results in powders made of irregular shaped particles
with a low bulk density and a bad flow behavior. With the aim to improve the flowability of grinded powders
and, thus, the SLS processability, a thermal process for particle shape modification was developed. This has been
applied successfully for a broad variety of thermoplasts. In this contribution, a modified design of a rounding
reactor with direct heating and optimized geometry is presented. The performance of the new design is assessed
by the rounding of commercially available polypropylene powders. The influence of the rounding process on the
packing density, flowability and particle size and shape distributions of the powders is investigated. Test
specimens produced by SLS were tested to assess the effect of the rounding process on the mechanical properties
of the produced parts.",,,,,,
"['Subramanian, Kamatchi', 'Barlow, J.W.', 'Marcus, H.L.']",2018-11-08T14:57:06Z,2018-11-08T14:57:06Z,1995,Mechanical Engineering,doi:10.15781/T2W37MF60,http://hdl.handle.net/2152/69880,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'copolymer', 'theoretical density']",Effect of Particle size on SLS and post-processing of Alumina with Polymer binders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be56a05b-172f-4d57-af2d-29b398985567/download,,"Alumina powders with mean particle size of 15 J.lm, 2 J.lm and 0.5 J.lm were processed by
SLS using polymer binders. The 2 J.lffi and 0.5 J.lm powders were given a thermal agglomeration
treatment before SLS. The green shapes after SLS were infiltrated with a colloid of aluminum
oxide. After infiltration the samples were given suitable heat-treatment to remove the polymer
binder by thermal decomposition followed by a sintering treatment at 16OOC. Green densities were
in the range of 45% of theoretical density for the agglomerates of 2 Jlm and 0.5 J.lffi powders while
it was about 36% of theoretical density for the 15 J.lffi powders. Sintered densities were about 55%
of theoretical density for the samples from agglomerates of 2 J.lffi and 0.5 Jlm powders while it was
42% of theoretical density for the samples from 15 J.lm powders. The strength of samples were
measured in the green state and after sintering to determine the effect of particle size.",,,,,,
"['Kerninon, J.', 'Mognol, P.', 'Hascoet, J.Y.', 'Legonidec, C.']",2021-09-23T21:11:53Z,2021-09-23T21:11:53Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88024', 'http://dx.doi.org/10.26153/tsw/14965']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['metal deposition processing', 'CAD systems', 'CAM systems', 'welding path strategies', 'mechanical engieering']",Effect of path strategies on metallic parts manufactured by additive process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e1d2da31-dd22-48ae-b80e-5ad414a89f4b/download,,"Metal deposition processing is well known for cladding by laser or welding process. 
Nevertheless, these systems are not optimized for direct manufacturing. One of the main lock 
is the need of dedicated CAD/CAM systems to slice and generate path strategies. 
Research at the IRCCYN laboratory (France) focus on the impact of cladding or welding head 
programming on dimensional properties and microstructure of the manufactured parts. In this 
context, path strategies are studied and different strategies are proposed and compared. 
This paper presents results for welding path strategies. The integration of deposition head on a 
6 axis robot system was used to improve slicing strategies and parts.",,,,,,
"['Vail, N.K.', 'Barlow, J.W.']",2018-04-17T18:09:12Z,2018-04-17T18:09:12Z,1991,Mechanical Engineering,doi:10.15781/T24X5504H,http://hdl.handle.net/2152/64337,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Microencapsulation', 'Glass', 'Sintering', 'Polymer', 'Spray Drying']",Effect of Polymer Coatings as Intermediate Binders on Sintering of Ceramic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d169afc9-b285-4ef7-b762-c7cbb69dc51b/download,,"It has been proposed that a thin polymer layer applied to the
surfaces of finely divided ceramic powders would serve as a suitable
intermediate binder for Selective Layer Sintering of ceramic pans. In this
study, the effects of completeness and fraction of coa nd particle size
distribution on sintering rates and strengths of coated ridized glass are
examined. The effect of the coating as a binder during Selective Layer
Sintering as well as the binder's burnout capability during post processing
steps are also investigated.",,,,,,
"['Wang, Z.', 'Smith, D.E.']",2021-11-03T20:50:19Z,2021-11-03T20:50:19Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89930,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['nozzle flow', 'fiber orientation', 'die swell', 'carbon fiber', 'extrusion', 'fused filament fabrication']",The Effect of Polymer Melt Rheology on Predicted Die Swell and Fiber Orientation in Fused Filament Fabrication Nozzle Flow,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4262946e-0a9e-402a-89ba-4561762703e1/download,University of Texas at Austin,"Short carbon fibers suspended in the polymer feedstock enhances the mechanical
performance of products produced with Fused Filament Fabrication (FFF). As the melted
filament is extruded and deposited on a moving platform, the velocity gradients within the
polymer melt flow orientate the fibers, and the final orientation has a direct effect on the
mechanical properties of printed bead. This paper numerically simulates an FFF nozzle flow,
including the extrudate material beyond the nozzle exit. Finite element simulations of the
extrusion process are performed with Generalized Newtonian Fluid (GNF) models and a
viscoelastic rheology model, included in ANSYS Polyflow, to evaluate the polymer melt
velocity field and predict die swell. Fiber orientation tensors are computed along streamlines
using the Fast Exact Closure and Folgar-Tucker isotropic rotary diffusion. The predictions
indicate that shear thinning behavior reduces the die swell but viscoelastic rheology significantly
intensifies the extrudate swell. Orientation tensor values calculated from the flow results of the
viscoelastic model yields lower principal alignment in printed beads than those computed with
GNF models.",,,,,,
"['Billah, Kazi Md Masum', 'Coronel, Jose Luis Jr', 'Wicker, Ryan B.', 'Espalin, David']",2021-11-09T15:44:07Z,2021-11-09T15:44:07Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90100', 'http://dx.doi.org/10.26153/tsw/17021']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['porosity', 'electrical insulation', 'heat dissipation', '3D printed electronics', 'embedded wires', 'fused deposition modeling']",Effect of Porosity on Electrical Insulation and Heat Dissipation of Fused Deposition Modeling Parts Containing Embedded Wires,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf6b3f18-1211-4ff8-a73c-7c49dea78783/download,University of Texas at Austin,"While the effects of porosity on the mechanical strength of fused deposition modeling (FDM) parts have
been thoroughly investigated, there exists a need for evaluating electrical and thermal properties. This work
describes the method of determining the effect of porosity that resembles 3D printed electronics. In addition to
mechanical strength, determination of desirable limit of electrical insulation and heat dissipation will allow the
additive manufacturing community to fabricate power electronics components with reduced cost and improved
performance. For experimentation, three different sets of coupons were fabricated using Polycarbonate (PC)
thermoplastic with embedded bare copper wire. Characterization included high electrical stresses and thermal
testing to determine the effect of porosity on insulation and heat dissipation, respectively. During electrical
characterization, higher wire density resulted in reduced breakdown strength. In thermal test, the comparisons
between as fabricated and heat-treated specimen showed that heat dissipation increased by an average of 30 % to
40 %.",,,,,,
"['Almangour, B.', 'Yang, J.M.']",2021-10-20T21:57:06Z,2021-10-20T21:57:06Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89372,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'selective laser melting', 'porosity', 'heat treatment', 'HIP']",Effect of Post-Processing on the Microstructure and Mechanical Properties of Ultra-Low Carbon Steel Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56fdcf2c-80b6-4624-848e-873413bd1367/download,University of Texas at Austin,"In this study, the effects of heat treatments and hot-isotactic pressing (HIP) on the
microstructure and mechanical properties of ultra-low carbon steel produced using selective laser
melting (SLM) were investigated. Powder and prototypes characterizations including XRD phase
analysis, microstructural observations, and hardness were performed. It was found that heat
treatments at 1000 ºC and HIP process improved inter-particle bonding very slightly. Significant
increases in the grain size were observed for the annealed specimens at 600ºC and above as well
as after HIP due to recrystallization and further grain growth, which coincide with the drop in
hardness.",,,,,,
"['Poudel, Arun', 'Soltani-Tehrani, Arash', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-25T14:10:36Z,2023-01-25T14:10:36Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117287', 'http://dx.doi.org/10.26153/tsw/44168']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Powder characteristics', 'Particle size distribution', 'Volumetric defects', 'Fatigue performance']",Effect of Powder Characteristics on Fatigue Performance of Additively Manufactured 17-4 PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f73b1f4e-0ee4-4048-802d-a8239a7cf421/download,,"The characteristics of powder feedstock used during laser powder bed fusion (L-PBF) influence 
the mechanical performance of the fabricated parts. The flowability, spreadability, and internal 
porosity of the powder can affect the porosity formation and thus, impact the fatigue performances. 
Two batches of 17-4 precipitation hardening stainless steel powders supplied by two different 
vendors were used to fabricate the L-PBF specimens and investigate the effect of powder 
characteristics on porosity and fatigue behavior. The powder batch with a wider particle size 
distribution, higher compressibility, higher cohesion between powder particles, and internal 
porosity resulted in a higher defect content in the fabricated specimens. Higher defect content led 
to inferior fatigue resistance along with more scatter in the fatigue lives. Fractography revealed the 
fatigue crack initiation from spherical pores as well as the lack of fusions in both batches.",,,,,,
"['Poudel, Arun', 'Sotani-Tehrani, Arash', 'Shao, Shuai', 'Shamsaei, Nima']",2021-12-06T22:07:14Z,2021-12-06T22:07:14Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90691', 'http://dx.doi.org/10.26153/tsw/17610']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'tensile properties', 'powder characteristics', 'powder flowability', 'LB-PBF']",Effect of Powder Characteristics on Tensile Properties of Additively Manufactured 17-4 PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/351d7255-8b30-4bd2-9593-2b06b4b48030/download,University of Texas at Austin,"Laser beam powder bed fusion (LB-PBF) process uses metallic powders as feedstock, whose
particle characteristics such as cohesion, compressibility, size distribution, etc., can vary and affect
the mechanical performance of the fabricated parts. In this study, two powder batches of 17-4
precipitation hardening (PH) stainless steel (SS) supplied by EOS (Batch 1) and Carpenter
Technology (Batch 2) were used to fabricate specimens using identical process parameters to
understand the effects of particle characteristics on defect content as well as tensile performance
of the LB-PBF specimens. Higher cohesion and compressibility as well as lower sphericity in
Batch 2 resulted in specimens with higher porosity levels. During tensile testing, the higher
porosity level in Batch 2 yielded lower ductility. In contrast, the microstructure was observed to
be less sensitive to particle characteristics because of which the tensile strengths of the specimens
were found to be comparable to each other.",,,,,,
"['Vunnam, S.', 'Dobson, S.', 'Saboo, A.', 'Frankel, D.', 'Sudbrack, C.', 'Starr, T.L.']",2021-11-18T00:06:37Z,2021-11-18T00:06:37Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90364', 'http://dx.doi.org/10.26153/tsw/17285']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['17-4 PH stainless steel', 'selective laser melting', 'electron backscatter diffraction', 'EBSD', 'phase composition', 'mechanical properties', 'H900 hardening']",Effect of Powder Chemical Composition on Microstructures and Mechanical Properties of L-PBF Processed 17-4 PH Stainless Steel in the As-Built and Hardened-H900 Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/924e6103-acec-42c1-8535-1d2e74efafb6/download,University of Texas at Austin,"Post-build heat treatments such as solutionizing and precipitation hardening are recommended
for selective laser melting (SLM) processed components to achieve a homogeneous
microstructure. In this study, the effect of powder elemental composition on microstructures and
mechanical properties of SLM processed 17-4 PH was studied in the as-built and precipitation
hardened (H900) condition without prior solutionizing. Microstructural characterization
demonstrated that H900 increased martensite phase composition for samples from powder with
low chromium to nickel equivalent (Creq/Nieq) value, whereas no significant difference was
observed for the samples from powders with high Creq/Nieq value. None of the specimens exhibited
austenite reversion and strain hardening behavior in the as-built and H900 conditions. Low
Creq/Nieq specimen exhibited higher yield and tensile strengths, and microhardness from H900,
which are comparable to H900 wrought sample. However, no significant improvement in total
elongation was observed other than uniform elongation for low Creq/Nieq specimen.",,,,,,
"['Niino, Toshiki', 'Sato, Kazuki']",2021-09-28T19:21:48Z,2021-09-28T19:21:48Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88159', 'http://dx.doi.org/10.26153/tsw/15100']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['powder compaction', 'plastic laser sintering fabrication']",Effect of Powder Compaction in Plastic Laser Sintering Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f757c9f8-faf6-4eb3-a499-114f378bb0e2/download,University of Texas at Austin,"Powder compaction is introduced into plastic laser sintering fabrication. Compaction was
carried out by using a roller of which rotation speed is independently controlled of its
traversing speed. This additional process improved packing density of powder bed by a
factor of 20% and reduced residual porosity of obtained parts by a factor of 30%. As an
advantage, powder compaction can improve mechanical strength of parts of
semi-crystalline powder, but increases excessive sinter to reduce fabrication accuracy
especially in fabrication of amorphous plastic. This paper presents characteristics of the
powder compaction process itself and its effects on performance of obtained parts.",,,,,,
"['Carrion, Patricio E.', 'Soltani-Tehrani, Arash', 'Thompson, Scott M.', 'Shamsaei, Nima']",2021-11-11T15:05:48Z,2021-11-11T15:05:48Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90212', 'http://dx.doi.org/10.26153/tsw/17133']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser-powder bed fusion', 'Ti-6Al-4V', 'fatigue life', 'powder degradation', 'powder recycling']",Effect of Powder Degradation on the Fatigue Behavior of Additively Manufactured As-Built Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9110d0df-b1ab-489b-8777-77cda3e9a761/download,University of Texas at Austin,"Additive manufacturing (AM) technology has enabled many industries to generate functional parts
with an increased level of complexity via a layer-by-layer melting. In laser-powder bed fusion (L-PBF), the most commonly used AM process for metals, powder is often recycled due to its high
cost. However, there is no comprehensive study on how recycling powder affects its rheological
properties, and the mechanical and fatigue behavior of the final manufactured part. In this study,
a comparison of new and used Ti-6Al-4V powder characteristics was made. The comparison
includes morphology, size distribution, as well as monotonic tensile and fatigue behavior of
fabricated specimens. Conclusions and suggestions on powder recycling are made. Results indicate
that the powder particle size distribution (PSD) becomes narrower and the morphology of the
particles change with recycling. However, no comparable effect was observed on the monotonic
tensile and fatigue behavior of the AM as-built Ti-6Al-4V specimens.",,,,,,
"['Heigel, J.C.', 'Lane, B.M.']",2021-11-03T22:09:14Z,2021-11-03T22:09:14Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89948,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['thermographic measurement', 'scan track', 'cooling rate', 'melt pool length', 'in-situ', 'powder bed fusion']",The Effect of Powder on Cooling Rate and Melt Pool Length Measurements Using In-Situ Thermographic Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/95a52c07-1d32-44ad-9075-7fe3df4e99b8/download,University of Texas at Austin,"High-speed thermal cameras enable in situ measurement of the temperatures in and
around melt pools generated during powder bed fusion processes. These measurements
can be used to validate models, to monitor the process, and to understand the
microstructure formed during the process. Unfortunately, pre-placed powder layers
complicate the measurement due to spatter and irregular surfaces that impact emissivity.
The objective of this work is to present high speed thermographic measurements of single
and multiple scan tracks on substrates with and without pre-placed powder and to analyze
and compare the impacts of powder on melt pool length and cooling rate measurements.",,,,,,
"['Chen, Xueyang', 'Yan, Lei', 'Li, Wei', 'Liou, Frank', 'Newkirk, Joe']",2021-10-27T21:43:34Z,2021-10-27T21:43:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89624,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['direct laser metal deposition', 'powder mixture', 'particle size', 'Ti-6Al-4V']",Effect of Powder Particle Size on the Fabrication of Ti-6Al-4V using Direct Laser Metal Deposition from Elemental Powder Mixture,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fdd8627d-fe9c-4586-bcc0-e17f7c5f92de/download,University of Texas at Austin,"Direct Laser Metal Deposition (LMD) was used to fabricate thin-wall Ti-6Al-4V using the
powder mixture of Ti-6 wt.%Al-4 wt.%V. Scanning electron microscopy (SEM), optical
microscopy (OM) and energy dispersive spectroscopy (EDS) were employed to examine the
chemical composition and microstructure of the as-deposited sections. Vickers hardness tests were
then applied to characterize the mechanical properties of the deposit samples which were
fabricated using pre-mixed elemental powders. The EDS line scans indicated that the chemical
composition of the samples was homogenous across the deposit. X-ray diffraction (XRD) was used
for the phase identification. After significant analysis, some differences were observed among two
sets of deposit samples which varied in the particle size of the mixing Ti-6wt.%Al-4wt.%V powder.
It could be found that the set with similar particle number for Ti, Al and V powder made
composition much more stable and could easily get industry qualified Ti-6Al-4V components.",,,,,,
"['Mahtabi, MohammadBagher', 'Yadollahi, Aref', 'Stokes, Ryan', 'Morgan-Barnes, Courtney', 'Young, Joseph', 'Doude, Haley', 'Bian, Linkan']",2023-01-26T14:12:44Z,2023-01-26T14:12:44Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117302', 'http://dx.doi.org/10.26153/tsw/44183']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Powder recycling', 'Virgin powder', 'Powder flowability', 'Powder size distribution']",Effect of Powder Reuse on Microstructural and Fatigue Properties of Ti-6Al-4V Fabricated via Directed Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4b964bd-b7b5-425e-a881-18d765c562be/download,,"In metal additive manufacturing (AM) processes, due to the high cost of metal powder, it 
is common to reuse the collected powder from the build envelope for future builds. Powder reuse 
may adversely affect the powder characteristics, including the flowability, size distribution, 
chemical composition, resultant microstructural, and consequently, mechanical properties of the 
fabricated parts. This study aims to investigate the effect of powder reuse on the microstructural 
features and fatigue performance of Ti-6Al-4V specimens fabricated using a directed energy 
deposition (DED) process. Characteristics of reused powder particles, such as the size distribution 
and chemical composition, were evaluated and compared with that of virgin powder. 
Microstructural features and characteristics of the process-induced defects were examined using 
scanning electron microscopy and x-ray computed tomography, respectively. Fatigue performance 
of the specimens fabricated using reused powder was evaluated and compared to their control 
counterparts, fabricated using virgin powder.",,,,,,
"['Mahtabi, MohammadBagher', 'Yadollahi, Aref', 'Stokes, Ryan', 'Morgan-Barnes, Courtney', 'Young, Joseph', 'Doude, Haley', 'Bian, Linkan']",2023-01-19T16:02:58Z,2023-01-19T16:02:58Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117246', 'http://dx.doi.org/10.26153/tsw/44127']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Powder recycling', 'Virgin powder', 'Powder flowability', 'Powder size distribution']",Effect of Powder Reuse on Microstructural and Fatigue Properties of Ti-6Al-4V Fabricated via Directed Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9aef631-883c-481e-9ae3-1e39ee42754a/download,,"In metal additive manufacturing (AM) processes, due to the high cost of metal powder, it 
is common to reuse the collected powder from the build envelope for future builds. Powder reuse 
may adversely affect the powder characteristics, including the flowability, size distribution, 
chemical composition, resultant microstructural, and consequently, mechanical properties of the 
fabricated parts. This study aims to investigate the effect of powder reuse on the microstructural 
features and fatigue performance of Ti-6Al-4V specimens fabricated using a directed energy 
deposition (DED) process. Characteristics of reused powder particles, such as the size distribution 
and chemical composition, were evaluated and compared with that of virgin powder. 
Microstructural features and characteristics of the process-induced defects were examined using 
scanning electron microscopy and x-ray computed tomography, respectively. Fatigue performance 
of the specimens fabricated using reused powder was evaluated and compared to their control 
counterparts, fabricated using virgin powder.",,,,,,
"['Nezhadfar, P.D.', 'Soltani-Tehrani, Arash', 'Shamsaei, Nima']",2021-11-17T23:54:01Z,2021-11-17T23:54:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90360', 'http://dx.doi.org/10.26153/tsw/17281']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser beam powder bed fusion', 'LB-PBF', 'preheating', 'stainless steel', 'porosity', 'mechanical properties', 'microstructure']",Effect of Preheating Build Platform on Microstructure and Mechanical Properties of Additively Manufactured 316L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/627329fa-e9c1-411e-b85b-f8d67c447fd9/download,University of Texas at Austin,"This study aims to understand the effect of build platform preheating on the microstructural
features and mechanical properties of 316L stainless steel (SS) fabricated via laser beam powder
bed fusion (LB-PBF) process. Two sets of specimens were fabricated on a non-preheated build
platform and the build platform preheated to 150 °C. Thermal simulations are carried out using
ANSYS using additive manufacturing module to investigate the variation in thermal history
experienced by the specimens in each condition. Microstructural features are analyzed via
simulation, and the results are validated experimentally. In addition, the effect of preheating on the
porosity size and distribution is evaluated using digital optical microscopy. Mechanical properties
of specimens from each condition are further assessed and correlated to the variations in
microstructure and defect size distributions.",,,,,,
"['Myers, K.', 'Paterson, A.', 'Iizuka, T.', 'Klein, A.']",2021-11-16T15:59:44Z,2021-11-16T15:59:44Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90324', 'http://dx.doi.org/10.26153/tsw/17245']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['print speed', 'surface roughness', 'density uniformity', 'binder jetting', 'binder jet 3D printing']",The Effect of Print Speed on Surface Roughness and Density Uniformity of Parts Produced Using Binder Jet 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4287838f-ef54-4cae-b8b5-f21c506c7864/download,University of Texas at Austin,"One of the main benefits of binder jetting is the ability to print quickly compared to other
metal additive manufacturing methods. Demand for higher throughput continues to increase, but
the effects of faster print speeds on part outcomes are not yet clearly understood. MIM powders
are used to achieve optimal density and surface finish. Printing at slower speeds results in densities
near 98% and average surface roughness values as low as 4 μm (Ra), in the as-sintered condition.
In this study, spread speeds were varied in order to understand the effect of print speed on surface
roughness. 316L D90 -22 μm powder was used to print with 3 different spread speeds, 2 different
layer thicknesses, and 2 different printhead droplet sizes. The surface finish and density were
quantified for the sintered parts that were oriented at 0, 22.5, and 45 degrees with respect to the Z-direction.",,,,,,
"['Moreno-Núñez, Benjamin A.', 'Trevino-Quintanilla, Cecilia D.', 'Esponiza-Garcia, Juan Carlos', 'Uribe-Lam, Esmeralda', 'Cuan-Urquizo, Enrique']",2024-03-27T03:55:34Z,2024-03-27T03:55:34Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124478', 'https://doi.org/10.26153/tsw/51086']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fused filament fabrication', 'statistical analysis', 'fractional fractorial design', 'internal geometry', 'thermoplastics']",Effect of Printing Parameters on the Internal Geometry of Products Manufactured by Fused Filament Fabrication (FFF),Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e98090f-4507-4ea4-823a-cb4b47bf1710/download,University of Texas at Austin,"The internal geometry of a 3D-printed product determines its mechanical properties. In Fused
Filament Fabrication (FFF) the filaments that build up the internal geometry suffer from variations
that have not been sufficiently studied. This research focused on identifying the parameters that
most affect the filaments and finding the optimum values to reduce their variations. A fractional
factorial design of experiments was used to detect the printing parameters of FFF that most affect
the width of extruded filaments, these results were also statistically analyzed. A response
optimization was done to obtain the values of the printing parameters that will give the closest
width of extruded filaments to the nozzle of the 3D printer used. Results showed layer height has
the largest impact on filament width variation.",,,,,,
"['Bauer, D.M.', 'Dietrich, K.', 'Walter, M.', 'Forêt, P.', 'Palm, F.', 'Witt, G.']",2021-10-26T19:27:34Z,2021-10-26T19:27:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89564,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['process gas', 'oxygen levels', 'powder quality', 'aluminum alloys', 'laser based powder bed melting', 'powder bed']",Effect of Process Gas and Powder Quality on Aluminum Alloys Processed by Laser Based Powder Bed Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50f7c352-076c-407a-81e6-b01d6684f367/download,University of Texas at Austin,"The production of parts and components by Additive Layer Manufacturing (ALM) offers potential cost benefits
for aeronautic applications. Laser Based Powder Bed Melting Process offers design flexibility while enabling
weight reduction due to topological optimization by substitute conventional design and manufacturing routes.
Especially aluminum alloys are highly sensitive to oxygen and hydrogen impurity during the process. Due to
this, it is mandatory to control precisely and hold a low oxygen level while processing. Hereby it is possible to
avoid any negative impact on the final mechanical properties as tensile strength and fatigue resistance.
For the investigations, aluminum powder (Al-Si-Mg) is used. This paper will present the influence of the
oxygen level during processing on the final mechanical properties of the part. Even if pure Argon is commonly
used to inert the chamber, different sources of oxygen like powder, equipment and gas supply have a negative
impact and will be investigated. [1]–[4]",,,,,,
"['Pegues, Jonathan', 'Leung, Kelvin', 'Keshtgar, Azadeh', 'Airoldi, Luca', 'Apetre, Nicole', 'Iyyer, Nagaraja', 'Shamsaei, Nima']",2021-11-02T13:43:33Z,2021-11-02T13:43:33Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89800,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['mechanical properties', 'microstructure', 'additive manufacturing', 'ICME', 'titanium alloys']",Effect of Process Parameter Variation on Microstructure and Mechanical Properties of Additively Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c30b2797-2968-4267-b82c-59fe027ab25b/download,University of Texas at Austin,"As additively manufactured (AM) parts become viable options for various structural
applications, it is essential to fully understand how various process parameters affect their
subsequent mechanical behavior. In this study, a process simulation package is utilized to model
the heat transfer during the laser-based powder bed fusion (L-PBF) process. Along with
mechanical properties, the model is capable of estimating porosity, density, and microstructural
evolution during the rapid cooling phases associated with L-PBF. Simulation results were
validated using experimentally measured mechanical properties of L-PBF Ti-6Al-4V specimens.
Tensile tests and microscopy were conducted for determining the effects of process parameters
(i.e. laser power, laser scan speed, hatch distance) on microstructure, strength, and ductility of
fabricated parts. Predictions from process simulations were compared with experimental results.
Validated process simulation packages, used and developed herein, can provide a low-cost means
for the quality control of AM parts.",,,,,,
"['Dilip, J.J.S.', 'Stucker, Brent', 'Starr, Thomas L.']",2021-10-13T20:24:33Z,2021-10-13T20:24:33Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88777', 'http://dx.doi.org/10.26153/tsw/15711']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['HY100 steel', 'selective laser mleting', 'process parameters', 'tempering treatment', 'temper heat treatment']",Effect of Process Parameters and Heat Treatment on the Microstructure and Mechanical Properties of SLM-built HY100 Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b8c89cb-bac2-4dab-90bd-ee214ff9e7d2/download,University of Texas at Austin,"HY100 is a high strength low alloy steel used for naval and pressure vessel applications. In general, the
alloy is used in the quenched and tempered condition. In the present work, fully dense metallic samples
were produced from HY100 pre-alloyed powders using selective laser melting (SLM). Test
samples were built with varying process parameters (scan speed and laser power). The SLM-built
samples were given direct tempering treatment and a standard quench and temper heat treatment.
Tensile properties of the samples were evaluated in direct temper, and quench and temper conditions.
The study investigates the influence of process parameters and heat treatment on the microstructure and
mechanical properties of SLM-built HY100 steel.",,,,,,
"['Izadi, Mojtaba', 'Farzaneh, Aidin', 'Gibson, Ian', 'Rolfe, Bernard']",2021-11-03T20:44:28Z,2021-11-03T20:44:28Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89928,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['stainless steel 316', 'process parameters', 'macrostructure', 'mechanical properties', 'direct energy deposition']",The Effect of Process Parameters and Mechanical Properties of Direct Energy Deposited Stainless Steel 316,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee88a340-0fcc-4191-9c87-d5968f7e7408/download,University of Texas at Austin,"Process parameters in Direct Energy Deposition (DED) Additive Manufacturing are
playing an important role in order to fabricate desired parts. In this research, we studied the
effect of 3 process parameters, namely laser power, scan speed and powder feed rate. Based on
variation of these parameters, we examined macrostructure and mechanical properties of
stainless steel 316 fabricated parts, employing an orthogonal L9 array using the Taguchi
technique. The results showed laser power to be the most effective factor whereas scan speed
and powder feed rate were respectively less effective. In addition, effect of height of deposition
was also considered. The results indicated change in macrostructure with increasing height.
Finally, validation of a previously defined energy density equation for the DED process was
studied. The results clearly showed the current energy density equation cannot fully represent
a relation between input energy and output geometry, macrostructure, and mechanical
properties.",,,,,,
"['Kanger, Cody', 'Hadidi, Haitham', 'Akula, Sneha', 'Sandman, Chandler', 'Quint, Jacob', 'Alsunni, Mahdi', 'Underwood, Ryan', 'Slafter, Cody', 'Sonderup, Jason', 'Spilnek, Mason', 'Casias, John', 'Rao, P.', 'Sealy, M.P.']",2021-11-02T18:00:29Z,2021-11-02T18:00:29Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89840,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['fused filament fabrication', 'shot peening', 'ABS', 'strength', 'elongation']",Effect of Process Parameters and Shot Peening on Mechanical Behavior of ABS Parts Manufactured by Fused Filament Fabrication (FFF),Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b3ca70e-79aa-4ff2-a083-1cb4828a15b3/download,University of Texas at Austin,"The goal of this research was to understand how shot peening affected the tensile strength and
elongation of ABS polymer parts between three process parameters: layer height, infill angle, and
outer shell quantity. Experiments were conducted using a Hyrel 30M fused filament fabrication
(FFF) printer to produce ASTM 638D-IV samples. This is an important area of research because
3D printed polymers have typically been limited to prototyping applications due to low strengths
and stiffness. Traditional means of improving a polymer’s mechanical properties are changing the
structural or chemical makeup. However, shot peening, a surface treatment commonly used to
improve mechanical properties of metals, was hypothesized to have a statistically significant effect
on the tensile strength and elongation of polymer parts. Results showed that shot peening had a
significant effect on decreasing the tensile strength. Although not statistically significant, samples
did show an increase in elongation after shot peening.",,,,,,
"['Madireddy, G.', 'Montazeri, M.', 'Curtis, E.', 'Berger, J.', 'Underwood, N.', 'Khayari, Y.', 'Marth, B.', 'Smith, B.', 'Christy, S.', 'Krueger, K.', 'Sealy, M.P.', 'Rao, P.']",2021-11-04T15:04:00Z,2021-11-04T15:04:00Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89980', 'http://dx.doi.org/10.26153/tsw/16901']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'shot peening', 'polymer', 'strength', 'deflection']",Effect of Process Parameters and Shot Peening on the Tensile Strength and Deflection of Polymer Parts Made Using Mask Image Projection Stereolithography (MIP-SLA),Conference paper,https://repositories.lib.utexas.edu//bitstreams/24ca5417-24e1-4339-82dd-02c0189e9d99/download,University of Texas at Austin,"Mask Image Projection Stereolithography (MIP-SLA) is an additive manufacturing technique
in which a liquid photopolymer resin is hardened from exposure to ultraviolet (UV) light. Shot
peening is a surface treatment to improve the mechanical properties of components. The goal of
this work was to quantify the effect of SLA print process parameters, namely layer height and UV
exposure, and shot peening on the longitudinal tensile strength of ASTM D638 Type 5 test
artifacts. Test parts were created using a central composite experimental plan on a B9 Creator
desktop SLA machine. Deflection of the pseudo-Almen strips after shot peening was measured
using a digital camera to identify desired peening condition. Post-shot peening tensile strength was
measured for the ASTM D638 Type 5 parts. Shot peening generally decreased the strength of MIPSLA parts.",,,,,,
"['Liao, Hailong', 'Zhu, Haihong', 'Zhu, Junjie', 'Chang, Shijie', 'Zeng, Xiaoyun']",2021-11-18T02:14:40Z,2021-11-18T02:14:40Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90410', 'http://dx.doi.org/10.26153/tsw/17331']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['process parameters', 'relative density', 'loss rate', 'loss mechanism', 'Al2O3', 'Al2O3-Al cermet', 'selective laser melting']",Effect of Process Parameters on Selective Laser Melting Al2O3-Al Cermet Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e753ae1-8e5f-4dcd-ae17-a37101488a2e/download,University of Texas at Austin,"The cermet composite material is one of the researches focuses in the field of materials, for it can combine
the toughness of metal and the hardness of ceramics. In this work, Al2O3-Al cermet composite with a mass
ratio of 1:1 was fabricated by selective laser melting process. The effect of process parameters on the relative
density and Al2O3 loss rate, as well as the Al2O3 loss mechanism, was investigated in detail. The results show
that Al2O3 undergoes melt recrystallization and is significantly aggregated. The aggregated Al2O3 exhibits a
network distribution in the metal matrix. The process parameters have a great influence on the relative density
and the Al2O3 loss rate. As the scanning speed decreases, the relative density and the Al2O3 loss rate are
changed with a contrary tendency. The loss mechanism is that the aluminum acts as a reducing agent, causing
the Al2O3 becoming a gaseous substance Al2O during selective laser melting process.",,,,,,
"['Xue, Fangkai', 'Robin, Guillaume', 'Boudaoud, Hakim', 'Cruz Sanchez, Fabio A.', 'Daya, El Mostafa']",2021-12-01T23:25:15Z,2021-12-01T23:25:15Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90654', 'http://dx.doi.org/10.26153/tsw/17573']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['vibration properties', 'fused filament fabrication', 'FFF', 'modal analysis', 'poylactic acid', 'PLA', 'design of experiments', 'DoE']",Effect of Process Parameters on the Vibration Properties of PLA Structure Fabricated by Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/920520b7-c8ac-4f0e-b084-cd7ec4227e98/download,University of Texas at Austin,"Advances in Fused Filament Fabrication (FFF) enable the design and manufacturing of
multi-material and multi-functional structure that can potentially be used to develop light weight
and high damping structures for vibration control. However, very few studies mention the
vibration characteristics of FFF printed structures. This paper investigates the effect of four
process parameters, raster angle, nozzle temperature, layer height and deposition speed, on the
vibration properties of FFF printed Polylactic Acid (PLA) structure through modal
analysis and design of experiment. The effects of all four parameters show a good
agreement on the first fives modes of resonance. It was found that raster angle significantly
affects both resonance frequency (16.6%) and loss factor (7.5%). Meanwhile, the impact of
the other three parameters is relatively low (less than 4%), which is different from previous
research results on static mechanical properties. All these results provide a guidance for further
application of FFF in vibration field.",,,,,,
"['Nie, Xiaojia', 'Zhang, Hu', 'Zhu, Haihong', 'Hu, Zhiheng', 'Zeng, Xiaoyan']",2021-11-10T22:57:15Z,2021-11-10T22:57:15Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90201', 'http://dx.doi.org/10.26153/tsw/17122']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['processing parameter', 'zirconium modified', 'Al-Cu-Mg alloys', 'selective laser melting']",The Effect of Processing Parameter on Zirconium Modified Al-Cu-Mg Alloys Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/290b3450-f0b9-4ae7-9e75-fc412635ea55/download,University of Texas at Austin,"The newly designed alloy compositions for selective laser melting (SLM) have
aroused great interest. In this study, zirconium modified Al-Cu-Mg alloys were
fabricated by SLM. Results show that crack-free samples with relative density of nearly
100% were obtained by optimizing the processing parameters. With the increase of
scanning speed, the relative density decreases due to insufficient energy input. In
addition, the microstructure transforms from homogeneous to bio-modal, the reason is
the unstable flows caused by the high scanning speed. The small hatching space will
provide more energy input and preheat, leading to the coarse surface.",,,,,,
"['Badrinarayan, B.', 'Barlow, J.W.']",2018-10-04T19:32:59Z,2018-10-04T19:32:59Z,1995,Mechanical Engineering,doi:10.15781/T28W38M8W,http://hdl.handle.net/2152/68706,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'laser processing', 'CAD']",Effect of Processing Parameters In SLS Of Metal-Polymer Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5df7e1c7-c167-4fb0-8fe6-cce5a913378d/download,,"This paper describes the effect of processing parameters in SLS of metal-polymer powder
mixtures. Test bars for measurement of strength and density were made from copper-PMMA
powder mixtures using SLS. The effect of Energy Density during laser processing, effect of
vector length, bed temperature, polymer melt index and initial binder content on part strength and
density are discussed in this paper. The green part strengths and densities were found to increase
with Energy Density upto a value of 6.0 caVcm2 and then they drop off due to polymer
degradation. Parts made with lower vector lengths yielded higher strengths and densities than
those with higher vector lengths. Parts processed with a low melt index polymer binder (around
6.0 gmllOmin) showed higher strengths than parts processed with higher melt index binders.
High strength values were obtained for green parts made from powders that had a greater initial
binder content. Bed temperature did not have a very significant effect on part strength and
densities.",,,,,,
"['Olakanmi, E. O.', 'Cochrane, R. F.', 'Dalgarno, K. W.']",2020-03-09T15:20:20Z,2020-03-09T15:20:20Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80196', 'http://dx.doi.org/10.26153/tsw/7215']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Densification,Effect of Processing Parameters on the Density and Microstructure of Direct Laser Sintered Al-12Si Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/84136423-1739-4091-ad9f-aa12b5d0b48e/download,,"The effect of processing parameters on the sintering behaviour of gas atomised Al-12Si
powders has been investigated. Laser power, scanning rate, scan spacing and layer
thickness are found to control the densification and the resultant microstructural
characteristics of the laser sintered parts. It was found that sintered density increased as
the energy density increased reaching a maximum of 80.2% at an energy input per unit
volume of 67 J mm-3. For parts produced with a slightly lower power density (50 J mm-3), the microstructure consisted of fine dendrites with interconnected porosity while parts
fabricated with a slightly higher power density (100 J mm-3) were noted to have a
preponderance of coarse dendrites with a discontinuous network of irregular shaped pores
surrounded by a fully dense aluminium-silicon matrix.",,,,,,
"['Ge, Wenjun', 'Lin, Feng', 'Guo, Chao']",2021-10-13T19:27:18Z,2021-10-13T19:27:18Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88768', 'http://dx.doi.org/10.26153/tsw/15702']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['electron beam selective melting', 'Ti47Al2Cr2Nb', 'scan patterns', 'microstructure evolution', 'Ultimate Tensile Strength']",The Effect of Scan Pattern on Microstructure Evolution and Mechanical Properties in Electron Beam Melting Ti47Al2Cr2Nb,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ff1c6d4-8e64-4a6c-a9f3-b2be8ccd272c/download,University of Texas at Austin,"Ti47Al2Cr2Nb alloy square samples with dimensions of 20mm x 20mm x 5mm were
fabricated by electron beam selective melting. In order to study the effect of electron
beam scan pattern on the microstructure evolution, three different scan patterns were
employed: S-shaped scan line, Z-shaped scan line and interlayer orthogonal S-shaped
scan line. Microstructural and chemical analyses were conducted using optical
microscopy, scanning electron microscopy and energy differential system. It is worth
noting that the element Al loss rate was about 8% under different process parameters.
As a result, the microstructures of EBSM Ti47Al2Cr2Nb samples were composed of
columnar β grains, α/α2and α2/γ lamellar. Tensile tests were carried out to understand
the mechanical properties to the corresponding microstructures. Ultimate Tensile
Stress (UTS)at room temperature is much lower than that at a high temperature.",,,,,,
"['Anam, Md Ashabul', 'Dilip, JJS', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-12T22:37:31Z,2021-10-12T22:37:31Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88758', 'http://dx.doi.org/10.26153/tsw/15692']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'Inconel 625', 'scan patterns', 'microstructure', 'Nb grains', 'Mo grains']",Effect of Scan Pattern on the Microstructural Evolution of Inconel 625 during Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/64cccc2e-f959-41ee-9b2b-f96b2fca48c3/download,University of Texas at Austin,"Selective laser melting (SLM) involves highly localized heat input and directional solidification,
which enables novel microstructure control through the development of scanning strategies and
related process variables. A careful study of scan pattern is important to understand
microstructural evolution during SLM. In this study, various types of scanning strategies were
used to build samples of Inconel 625. Microstructure differences due to different scan patterns in
as-built Inconel 625 samples were then studied in detail. Microstructure samples showed grains
with cellular substructure with enriched regions of Nb and Mo in the inter arm spacing. The
grains were observed to grow preferentially in the build direction, but there were also clear
effects of grain orientation differences due to scan direction effects.",,,,,,
"['AlMangour, B.', 'Grzesiak, D.', 'Yang, J.M.']",2021-10-26T20:26:41Z,2021-10-26T20:26:41Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89578,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'porosity', 'microstructure', 'hardness']",Effect of Scanning Methods in the Selective Laser Melting of 316L/TiC Nanocomposites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68c69b88-6708-4bc7-917a-acc4b5b5af31/download,University of Texas at Austin,"Selective laser melting (SLM) is a promising additive manufacturing process that allows
for the fabrication of complex functional components by the selective layer-by-layer melting of
particles on a powder bed using a high-energy laser beam. In this study, the SLM process was
used to fabricate components of TiC/ 316L stainless steel nanocomposite using various laser
scanning methods. The results showed that the laser-scanning method used for the SLM process
affects the degree of densification, microstructure, and the hardness of the components produced.
We believe that the alternative fabrication route presented in this study should significantly
increase the use of nanocomposites.",,,,,,
"['Niu, F.Y.', 'Wu, D.J.', 'Ma, G.Y.', 'Zhou, S.Y.', 'Zhang, B.']",2021-10-13T19:59:18Z,2021-10-13T19:59:18Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88773', 'http://dx.doi.org/10.26153/tsw/15707']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['second-phase doping', 'Al2O3 ceramics', 'laser deposition', 'additive manufacturing', 'laser engineering net shaping']",Effect of Second-Phase Doping on Laser Deposited Al2O3 Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7dd4673e-f758-40f0-8cf0-664f8269ce39/download,University of Texas at Austin,"Direct fabrication of engineering ceramic components by additive manufacturing (AM) is a
relatively new method for producing complex mechanical structures. This study investigates how
a second-phase doping may affect Al2O3 ceramic parts deposited by AM with a laser engineered
net shaping (LENS) system. In this study, ZrO2 and Y2O3 powders are respectively doped into
Al2O3 powders at the eutectic ratio as second-phases to improve the quality of a deposited part.
The deposited Al2O3, Al2O3/ZrO2 and Al2O3/YAG (yttrium aluminum garnet) parts are examined
for their micro-structures and micro-hardness, as well as defects. The results show that doping of
ZrO2 or Y2O3 as a second-phase performs a significant role in suppressing cracks and in refining
grains of the laser deposited parts. The micro-hardness investigation reveals that the
second-phase doping does not result in much hardness reduction in Al2O3 and the two eutectic
ceramics are both harder than 1500 Hv. The study concludes that the second-phase doping is
good for improving laser deposited ceramic parts.",,,,,,
"['Majewski, C.E.', 'Hopkinson, N.']",2021-09-30T15:46:40Z,2021-09-30T15:46:40Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88268', 'http://dx.doi.org/10.26153/tsw/15209']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['section thickness', 'Laser Sintered parts', 'mechanical properties', 'tensile properties', 'Fracture Toughness', 'Additive Manufacturing']",Effect of Section Thickness and Build Orientation on Tensile Properties and Material Characteristics of Laser Sintered Nylon-12 Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a0fb70fb-0cb2-4499-9ca1-11a049b0a595/download,University of Texas at Austin,"It has been suggested that different section thicknesses in Laser Sintered parts may cause
variations in mechanical properties, and this has previously been demonstrated for some
properties (e.g. fracture toughness). The research presented here investigates whether the same
is true of tensile properties, and whether the orientation of parts within the build volume has any
effect on this. Results are presented for three different orientations of tensile specimens, at a
range of thicknesses from 2mm to 6mm, showing that, at any of the orientations tested, the
section thickness had no significant effect on any of the main tensile properties.
These results are in direct contradiction with related research investigating the effect of section
thickness on Fracture Toughness, where an increase in thickness also increased the toughness of
the parts. This highlights the importance to Additive Manufacturing users of identifying the
correct properties to assess when choosing a suitable process or material, and when designing
complex parts.",,,,,,
"['Fulcher, Ben', 'Leigh, David K.']",2021-10-06T20:33:27Z,2021-10-06T20:33:27Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88436', 'http://dx.doi.org/10.26153/tsw/15373']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'Melt Flow Index', 'Differential Scanning Calorimetry', 'polymer parts']",Effect of Segregated First and Second Melt Point on Laser Sintered Part Quality and Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2feea4d1-ee71-479b-a362-90a221c8ed28/download,University of Texas at Austin,"Efforts to tailor laser sintering polymers to enhance part quality, performance, and
processing have relied on the characterization of the polymers using Melt Flow Index (MFI) and
Differential Scanning Calorimetry (DSC). Two grades of laser sintering nylon polyamide are
compared and the resultant processing window, part quality, and mechanical behavior are
discussed. A better understanding of characterization techniques and the processing of laser
sintered polymers is leading to engineering thermoplastics for exclusive use in additive
manufacturing.",,,,,,
"['Hoskins, Dylan', 'Ajinjeru, Christine', 'Kunc, Vlastimil', 'Lindahl, John', 'Nieto, Daniel Moreno', 'Duty, Chad']",2021-11-10T21:54:06Z,2021-11-10T21:54:06Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90189', 'http://dx.doi.org/10.26153/tsw/17110']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['shear strain', 'extrusion viscosity', 'fiber reinforced polymers', 'acrylonitrile butadiene styrene', 'ABS', '3D printing', 'big area additive manufacturing', 'BAAM']",The Effect of Shear-Induced Fiber Alignment on Viscosity for 3D Printing of Reinforced Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db9eaddd-b3c6-4727-854a-a16f42e36d17/download,University of Texas at Austin,"Material printed with large scale additive manufacturing systems such as the Big Area
Additive Manufacturing (BAAM) system experience a wide range of shear rates during the
extrusion process. The shear rate can vary over five orders of magnitude as the material passes
through the single screw extruder and is deposited onto previous layers. When fiber reinforced
materials are deposited, the fibers can become highly aligned in the direction of flow due to the
high shear stresses experienced as the material passes through the nozzle. Therefore, accurate
analysis of the viscoelastic response of a polymer during extrusion should replicate these
conditions as closely as possible. This study evaluates the effect of a pre-conditioning shear
strain on the extrusion viscosity of carbon fiber reinforced acrylonitrile butadiene styrene (ABS).",,,,,,
"['Montgomery, Colt', 'Farnin, Christopher', 'Mellos, Greg', 'Brand, Michael', 'Pacheco, Robin', 'Carpenter, John']",2021-11-09T18:35:34Z,2021-11-09T18:35:34Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90112', 'http://dx.doi.org/10.26153/tsw/17033']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['surface finish', 'shield gas', 'metal powder', 'laser powder bed fusion', 'L-PBF']",Effect of Shield Gas on Surface Finish of Laser Powder Bed Produced Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2cd3bd39-eb04-465b-b4fe-76fb315bb712/download,University of Texas at Austin,"Additive manufacturing (AM) of metals is a novel manufacturing technique that allows
for net-shape or near net-shape parts to be produced quickly. Within additive manufacturing a
large concern is the produced surface finish, especially for upward and downward facing
surfaces on complex geometries. Surface finish is of utmost importance for many engineering
applications. In melting of powders, the gas used dominates the thermal conductivity of the metal
powder. Manipulation of the type of shield gas may provide a means to modify the surface finish
without adjustment of established lasing parameters and thereby produce a higher quality part
with minimal post processing. These results have potential applications in aerospace,
automotive, and biomedical sectors where surface finish requirements coupled with complex
geometries are extremely common.",,,,,,
"['Engeli, R.', 'Etter, T.', 'Geiger, F.', 'Stankowski, A.', 'Wegener, K.']",2021-10-20T22:46:53Z,2021-10-20T22:46:53Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89381,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'IN738LC', 'gas turbine', 'silicon', 'hot cracking']",Effect of Si on the SLM Processability of IN738LC,Conference paper,https://repositories.lib.utexas.edu//bitstreams/263116e2-82ca-4a40-bf5e-ab7a4cd34169/download,University of Texas at Austin,"Selective laser melting of high gamma-prime strengthened superalloys such as IN738LC is of interest in
stationary gas turbine applications. Differences have been obtained for the hot cracking susceptibility of
different powder batches during SLM processing and indications were found that also minor elements influence
the SLM processability. By processing a specific powder batch blended by different amounts of pure silicon, the
detrimental effect of this element during SLM could be shown. Therefore, the control of this minor element is
crucial to decrease the hot cracking tendency and can extend the SLM processing window of this alloy.",,,,,,
"['Norazman, Farhana', 'Hopkinson, Neil']",2021-10-07T18:53:19Z,2021-10-07T18:53:19Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88504', 'http://dx.doi.org/10.26153/tsw/15438']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['high speed sintering', 'thermoplastic elastomer', 'tensile properties', 'sintering power', 'flow agent']",Effect of Sintering Parameters and Flow Agent on the Mechanical Properties of High Speed Sintered Elastomer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fe3450d-f2ac-4883-a284-da8a39fea5b4/download,University of Texas at Austin,"High Speed Sintering (HSS) is an Additive Manufacturing process that creates parts by
sintering using inkjet and infra-red lamp technology rather than laser systems employed in
Laser Sintering (LS). This research investigated the effects of machine parameters (sintering
power, bed temperature) and the addition of fumed silica flow agent on the tensile properties
of thermoplastic elastomer parts processed using HSS. The results showed improved
elongation at break values by a factor of more than 2X compared to reported values for LS of
the same thermoplastic elastomers. At constant parameters, improved tensile strength and
tensile modulus were observed with the addition of flow agent into the sintering mixture.",,,,,,
"['Meng, S.', 'Mason, L.', 'Taylor, G.', 'Wang, X.', 'Leu, M.C.', 'Chandrashekhara, K.']",2021-11-01T22:17:18Z,2021-11-01T22:17:18Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89778,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['sparse-build tool', 'pressure', 'topology optimization', 'Ultem 9085', 'fused deposition modeling']",Effect of Sparse-Build Internal Structure on Performance of Fused Deposition Modeling Tools Under Pressure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a27c4ea-f7ab-44be-bd09-22f087bc6859/download,University of Texas at Austin,"Two different approaches to design a sparse-build tool for fabrication by the fused
deposition modeling (FDM) process are compared. One approach uses a 2D lattice structure and
the other approach is inspired by topology optimization. Ultem 9085 is used as the material, and
the amount of material used to build the tool is kept constant to ensure a fair comparison. A solid
tool is also included in the comparison. The performance of the tool under uniform pressure is
simulated using finite element analysis (FEA) and the accuracy of the FEA results is verified by
comparing them with experimentally measured data for a similar tool. The build material,
support material, build time, maximum displacement, and maximum von Mises stress are
compared for the three build approaches, with an emphasis on the pros and cons of each sparse-build tool with regards to performance under uniform pressure and fabrication by FDM.",,,,,,
"['Pegues, Jonathan', 'Roach, Michael', 'Williamson, R. Scott', 'Shamsaei, Nima']",2021-11-02T14:00:22Z,2021-11-02T14:00:22Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89805,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'additive manufacturing', 'surface effects', 'microstructure', 'titanium alloys']",Effect of Specimen Surface Area Size on Fatigue Strength of Additively Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/80824146-cb62-46dd-abb1-771da55a277a/download,University of Texas at Austin,"As additive manufacturing becomes an increasingly popular method for advanced
manufacturing of components, there are many questions that need to be answered before these
parts can be implemented for structural purposes. One of the most common concerns with
additively manufactured parts is the reliability when subjected to cyclic loadings which has been
shown to be highly sensitive to defects such as pores and lack of fusion between layers. It stands
to reason that larger parts will inherently have more defects than smaller parts which may result in
some sensitivity to surface area differences between these parts. In this research, Ti-6Al-4V
specimens with various sizes were produced via a laser-based powder bed fusion method. Uniaxial
fatigue tests based on ASTM standards were conducted to generate fatigue-life curves for
comparison. Fractography on the fractured specimens was performed to distinguish failure
mechanisms between specimen sets with different sizes.",,,,,,
"['Lu, Bing', 'Li, Mingyang', 'Lao, Wenxin', 'Weng, Yiwei', 'Qian, Shunzhi', 'Tan, Ming Jen', 'Leong, Kah Fai']",2021-11-15T21:21:27Z,2021-11-15T21:21:27Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90277', 'http://dx.doi.org/10.26153/tsw/17198']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D cementitious material printing', 'spray', 'material distribution', 'modelling']",Effect of Spray-Based Printing Parameters on Cementitious Material Distribution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ccd75d24-8487-4f30-8664-7641b59b8150/download,University of Texas at Austin,"In the past decade, 3D printing is getting into more and more industry areas including
building and construction. However, most 3D cementitious material printing processes are
limited in horizontal printing surface. Due to the nature of building and construction industry,
3D spray cementitious material printing process was developed to apply material in vertical or
even overhang surfaces. Unlike traditional manually operated spray method in building and
construction industry, 3D spray cementitious material printing process requires higher
accuracy on material distribution. In this paper, the effects of four printing parameters
(cementitious material flow rate, air flow rate, nozzle travel speed, nozzle standoff distance)
on material distribution in 3D spray cementitious material printing process were investigated
experimentally. An experimental model, which can be further used in the control of 3D spray
cementitious material printing process, was then developed upon on the results.",,,,,,
"['El Fazani, H.H.', 'Coil, J.D.A.', 'Shah, R.R.', 'Laliberte, J.F.']",2021-12-01T23:43:47Z,2021-12-01T23:43:47Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90661', 'http://dx.doi.org/10.26153/tsw/17580']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fused deposition modelling', 'fatigue crack', 'fatigue coupons', 'stress intensity factor']",The Effect of Stress Intensity Factor on Fatigue Life of AM Parts Made from Polymer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/abffc11b-3bfc-4698-8de3-a95dbde79848/download,University of Texas at Austin,"The fatigue characteristics of additively manufactured specimens was investigated. A
commercial acrylonitrile-butadiene-styrene (ABS) polymer (P430) was selected to manufacture
AM fatigue coupons due to its low cost and wide applications. A total of 30 fatigue coupons were
built on flat and on edge using a Stratasys SST 1200es fused deposition machine. The AM samples
were manufactured at different build orientations of 0°, 22.5°, 45°, 67.5°, and 90°. The objective
of this experiment is to investigate the influence of stress intensity factor on fatigue life of AM
polymer parts. The specimens were tested under low sinusoidal tension-tension fatigue loading.
The fatigue crack behaviour was monitored using a travelling microscope method. The stress
intensity factor was investigated as the cycles accumulated. The effect of stress intensity factor on
fatigue life was examined. The investigation of fatigue crack growth as a function of the number
of fatigue cycles was discussed. It was found the fatigue coupons manufactured at 0° build
orientation have a better fatigue life compared with the other build orientations. More investigation
is required for other AM parameters such as layer thickness, infill density, manufacturing process
to help better understand the fatigue performance of AM part made by polymer material. The
Scanning Electron Microscope (SEM) technology was used to characterize the fractured surfaces and void
distribution of AM fatigue parts. The void percentage was estimated. The results showed that AM fatigue
parts built on flat has a higher void percentage compared to the AM parts manufactured on edge.",,,,,,
"['Sparks, Todd', 'Ruan, Jianzhong', 'Fan, Zhiqiang', 'Bao, Yaxin', 'Liou, Frank']",2020-02-28T16:18:03Z,2020-02-28T16:18:03Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80114', 'http://dx.doi.org/10.26153/tsw/7135']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Aided Manufacturing Process,Effect of Structured Laser Pulses on Grain Growth in H13 Tool Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/92afa2e7-eb4b-41f0-a84e-cf3b7b27afcd/download,,,,,,,,
"['Joseph, Shine', 'Quiñones, Stella', 'Medina, Frank', 'Wicker, Ryan']",2020-03-10T14:13:08Z,2020-03-10T14:13:08Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80206', 'http://dx.doi.org/10.26153/tsw/7225']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Stereolithography,Effect of Surface Preparation Methods on Mechanical Properties of 3D Structures Fabricated by Stereolithography and 3D Printing for Electroless Ni Plating,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03b7ad0c-81ab-40e3-bd50-6e67467ba9e8/download,,"Stereolithography (SL) and 3D Printing (3DP) are useful technologies for
three-dimensional prototyping applications, providing highly accurate and detailed part
geometries with high quality surface finishes. It is desired to improve the materials
performance of the existing photocurable SL and 3DP resins for rapid tooling and other
functional applications by applying a nickel (Ni) coating. In this work, surface
preparation methods for electroless plating of commercial photopolymer resins such as
NanoFormTM15120 (NanoForm) and Objet FullCure®840 (Veroblue) were explored in
order to enhance the structural integrity of RP components. This study examined
different surface preparation methods (chemical etching) and their effect on the surface
morphology and mechanical strength of the polymers. It was observed that surface
preparation of the resins significantly affected the mechanical properties and Ni plating of
the substrate polymers. This is a critical step, since the Ni film takes on the surface
structure of the substrate.",,,,,,
"['Ordnung, D.', 'Metelkova, J.', 'Van Hooreweder, B.']",2024-03-25T23:41:42Z,2024-03-25T23:41:42Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124341', 'https://doi.org/10.26153/tsw/50949']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'surface quality', 'surface state', 'additive manufacturing']",Effect of surface state and material on surface quality enhancement by Dual Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf58b450-1138-47cc-a267-36d95f2544d1/download,University of Texas at Austin,"Parts produced by Laser Powder Bed Fusion typically exhibit a limited surface quality often requiring
systematic post-processing. The KU Leuven AM team recently developed a Dual Laser Powder Bed Fusion
strategy to improve the quality of inclined up-facing surfaces during building. It consists of two steps: (1) a pulsed
laser induces shock waves to remove powder from inclined surfaces, followed by (2) in-situ laser remelting of
the newly exposed surfaces. The first part of this paper covers the powder removal efficiency using shock waves
depending on the used material. A design of experiments was performed for horizontal samples of tool steels,
titanium and aluminium alloys. The second part deals with the effect of the initial surface state on the powder
removal efficiency for inclined surfaces (SaR,LT60=16.2 µm, SaR,LT120=24.0 µm). Finally, the third part
demonstrates the surface quality improvement, resulting in a reduction of Ra up to 61% for 15° inclinations.",,,,,,
"['Taminger, Karen M. B.', 'Hafley, Robert A.', 'Fahringer, David T.', 'Martin, Richard E.']",2020-02-14T15:47:59Z,2020-02-14T15:47:59Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79987', 'http://dx.doi.org/10.26153/tsw/7012']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Electron beam freeform fabrication,Effect of Surface Treatments on Electron Beam Freeform Fabricated Aluminum Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d22ce4d8-9f49-4e44-bafa-d15e6ccef846/download,,"Electron beam freeform fabrication (EBF3) parts exhibit a ridged surface finish typical of
many layer-additive processes. Thus, post-processing is required to produce a net shape with a
smooth surface finish. High speed milling, wire electrical discharge machining (EDM), electron
beam glazing, and glass bead blasting were performed on EBF3-built 2219 aluminum alloy parts
to reduce or eliminate the ridged surface features. Surface roughness, surface residual stress
state, and microstructural characteristics were examined for each of the different surface
treatments to assess the quality and effect of the surface treatments on the underlying material.
The analysis evaluated the effectiveness of the different surface finishing techniques for
achieving a smooth surface finish on an electron beam freeform fabricated part.",,,,,,
"['Sayah, Neshat', 'Smith, Douglas E.']",2024-03-25T22:36:42Z,2024-03-25T22:36:42Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124325', 'https://doi.org/10.26153/tsw/50933']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['SCF/ABS', 'carbon', 'LAAM', 'additive manufacturing']",Effect of the Print Bed Temperature on Void Distribution within the Microstructure of Short Carbon Fiber Reinforced/ABS Manufactured via Large Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e62fa1b4-7046-4e6a-817d-f13dec00cd53/download,University of Texas at Austin,"Short carbon fiber-reinforced polymer composite structures produced using Large Area Additive
Manufacturing (LAAM) have garnered significant attention due to the design flexibility, energy
savings, and materials selection associated with this process. However, the physical and
mechanical properties of the additively manufactured composite parts often fall below
expectations due to void formation between printed beads and within the microstructure of
individual beads. This study aims to investigate the effect of bed temperature on the microstructure
within the beads of two-layer Short Carbon Fiber reinforced Acrylonitrile Butadiene Styrene
(SCF/ABS) beads manufactured via the LAAM system. This study employs high-resolution 3D
micro-computed tomography (µCT) to evaluate the void shape and distribution within the
microstructure of composite parts printed at various bed temperatures. The results of this study
demonstrate substantial variation in the void volume fraction among four bead sets deposited at
different print bed temperatures. Moreover, within each part, a noticeable discrepancy in void
volume fraction is observed between the top and bottom bead of the two-bead test samples.
Preliminary results indicate that increasing the bed temperature from 25°C to 75°C reduces void
volume fraction within the microstructure of the composite parts. However, an opposite trend
emerges when the bed temperature is further increased to 100°C, increasing void volume fraction,
which needs further investigation to understand. This study also evaluated the void shapes through
the calculation of their sphericity. The preliminary results reveal that as the bed temperature
increases from 25°C to 75°C, the voids exhibit higher sphericity within the printed parts as the
interconnected voids decrease.",,,,,,
"['Nabil, S. T.', 'Arrieta, E.', 'Wicker, R. B.', 'Benedict, M.', 'Medina, F.']",2023-03-29T16:33:59Z,2023-03-29T16:33:59Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117683', 'http://dx.doi.org/10.26153/tsw/44562']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser Powder Bed Fusion(L-PBF)', 'Fatigue Life', 'Thermal Aging', 'AlSi10Mg', 'Hot-Isostatic Pressing']",Effect of Thermal Aging in the Fatigue Life of Hot Isostatic Pressed AlSi10Mg Fabricated by Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2567daf0-96b1-467e-b429-7a62b62a7373/download,,"AlSi10Mg is a widely used material in the aerospace industry. Extended exposure to elevated 
temperatures can have a detrimental effect on it. In this work, multiple AlSi10Mg horizontal bars 
and vertical rods were fabricated using an L-PBF system. Following ASTM F3318-18, the material 
blanks were HIPed (Hot Isostatic Pressed). Emulating service temperatures, these blanks were 
aged at 177°C for 10, 100, and 1000h. Fatigue test specimens were machined down from the aged 
blanks. The machined specimens were subjected to a force-controlled fatigue test as per ASTM 
E466-15 with two stress levels: one within the elastic range (62MPa) of the material and another 
close to UTS (124MPa). The results indicated that even aging for 10h can dramatically reduce the 
fatigue life of the alloy. The work concludes with discussion on the reduction of fatigue life and 
visible progressive change in the ductility of the alloy with respect to the aging time.",,,,,,
"['Khan, Md Faysal', 'Baig, Shaharyar', 'Ghiaasiaan, Seyed R', 'Gradl, Paul R', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-23T13:51:23Z,2023-01-23T13:51:23Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117277', 'http://dx.doi.org/10.26153/tsw/44158']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser powder bed fusion (L-PBF)', 'AlSi10Mg', 'Scalmalloy', 'Hot isostatic pressing  (HIP)', 'Microstructure', 'Tensile properties']",Effect of thermal post-processing on microstructure and tensile behavior of additively manufactured aluminum alloys (AlSi10Mg and Scalmalloy) via L-PBF: A comparative study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7c33099-07be-4516-9248-851913d1c73e/download,,"Additively manufactured aluminum (Al) alloys have recently received growing interest 
from different industrial sectors. This study compares the microstructure and tensile properties of 
two laser powder bed fused Al alloys, namely AlSi10Mg and Scalmalloy, in different heat-treated 
(HT) conditions i.e., stress-relief, T6, and hot isostatic pressing (HIP), as well as the non-heat-
treated condition. The microstructures were examined using scanning electron microscope, and 
the mechanical properties were evaluated using uniaxial tensile testing. For AlSi10Mg, Si-
networks were observed to break down, and Si- and Fe-rich particles precipitates form during HIP 
followed by T6. For Scalmalloy, the density of nanometer-sized intergranular Al3(ScxZr1-x) 
precipitates increased after only HIP. Furthermore, it was observed that the addition of HIP 
improved the tensile strengths of both alloys as compared to their AM as well as wrought 
counterparts in similar HT conditions.",,,,,,
"['Jandric, Z.', 'Ouyang, J.H.', 'Kovacevic, R.']",2019-10-24T17:32:16Z,2019-10-24T17:32:16Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77402', 'http://dx.doi.org/10.26153/tsw/4491']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Welding,Effect of Volume of Heat Sink on Process and Physical Properties of Parts Built by Welding Based SFF,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f09f9223-3946-44a3-bbbd-50d6a596631b/download,,"A new numerical simulation of the effect of the volume of the heat sink on the welding–based
deposition process is performed. For this purpose, the ANSYS parametric design language
(APDL) is applied. Due to the complex internal and/or external shapes of the designed threedimensional (3D) part, different heat transfer conditions are met during the building process.
The influences of the different heat transfer conditions on the physical part properties are also
investigated. The influence of the volume of the heat sink on the process and on the physical
properties is significant and can not be neglected. Extensive experiments are designed and
executed in order to verify the conclusions derived from the finite elements model results and to
investigate the material properties of the built part.",,,,,,
"['Uí Mhurchadha, S.M.', 'Marques, S.', 'Givet, L.', 'Raghavendra, R.']",2021-11-30T22:20:59Z,2021-11-30T22:20:59Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90569', 'http://dx.doi.org/10.26153/tsw/17488']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['high-cycle fatigue', 'metamaterials', 'laser powder bed fusion', 'fatigue life']",Effect of Voronoi Lattice Geometry on the Fatigue Performance of Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c467350b-a01a-4e7c-8032-e319e166627b/download,University of Texas at Austin,"This paper investigates the effect of strut thickness and number of pores on the fatigue performance of
Ti-6Al-4V voronoi lattice structures designed with the same part volume. The aim of this study is to establish
the variation in high cycle fatigue parameters for constant volume lattice structures designed with various
lattice parameters. Voronoi geometries were designed with varying strut thicknesses and number of pores to
maintain a constant specimen volume. The geometries were tested under compressive fatigue conditions at a
reversal ratio, R, of 0.1. It was found that the strut thickness has a significant influence on the fatigue life of
the lattice. An increase in the strut thickness by 100 µm can result in a reduction in fatigue life by up to a factor of
10. The results from this research can influence the design of lattice structures for osteointegration in loadbearing biomedical implant applications.",,,,,,
"['Spratt, Myranda', 'Anandan, Sudharshan', 'Hussein, Rafid M.', 'Newkirk, Joseph W.', 'Chandrashekhara, K.', 'Misak, Heath', 'Walker, Michael']",2021-11-09T20:04:21Z,2021-11-09T20:04:21Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90150', 'http://dx.doi.org/10.26153/tsw/17071']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['wall thickness', 'build quality', 'strength', '304L', 'thin-walled structures', 'lattice structures', 'selective laser melting', 'finite element analysis']",Effect of Wall Thickness and Build Quality on the Compressive Properties of 304L Thin-Walled Structures Fabricated by SLM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d878e105-33fe-4dab-9c0a-db87bbab7af0/download,University of Texas at Austin,"The specific strength of lightweight lattice structures built with SLM is of interest to the
aerospace industry. Honeycombs were manufactured with increasing wall thicknesses (which
increases density) and tested under compression. The optimal strength to density ratio was
determined from the resulting data. The build quality was also evaluated to determine how/if the
results were influenced by the specimen quality. Differences between the nominal and as-built
geometry were identified, but considered to be minimal. Microstructural evaluation of the
specimens revealed a possible dependence on the ‘border scan’ properties, as the thickness of the
specimens was such that the board scan made up most of the part. This work was used to validate
the results of a finite element analysis of this geometry.",,,,,,
"['Davis, Joy E.', 'Klingbeil, Nathan W.', 'Bontha, Srikanth']",2021-09-28T20:07:48Z,2021-09-28T20:07:48Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88170', 'http://dx.doi.org/10.26153/tsw/15111']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['laser beam-based fabrication', 'electron beam-based fabrication', 'additive manufacturing', 'repair applications', 'melt pool geometry', 'thin-wall structures', 'free-edges']",Effect on Free-Edges on Melt Pool Geometry and Solidification Microstructure in Beam-Based Fabrication of Thin-Wall Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e52529a4-08b2-4e65-a08b-2d1d7f548959/download,University of Texas at Austin,"The success of both laser and electron beam-based fabrication processes for additive manufacturing and repair applications requires the ability to control melt pool geometry while still maintaining a consistent and desirable microstructure. To this end, previous work by the authors has
employed point-heat source solutions to investigate the effects of process variables (beam power
and velocity) on melt pool geometry and solidification microstructure (grain size and morphology) in beam-based fabrication of thin-wall structures. However, these results were limited to
steady-state conditions away from free-edges. The current work extends the approach to investigate transient behavior in the vicinity of a free-edge.",,,,,,
"['Kolan, Krishna C.R.', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Velez, Mariano']",2021-10-05T14:14:56Z,2021-10-05T14:14:56Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88375', 'http://dx.doi.org/10.26153/tsw/15314']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', '13-93 bioactive glass', 'particle size', 'binder content', 'heat treatment']","Effect on Particle Size, Binder Content and Heat Treatment on Mechanical Properties of 13-93 Bioactive Glass Scaffolds",Conference paper,https://repositories.lib.utexas.edu//bitstreams/768fa75e-bfd0-4b0b-a25c-719c5b585e97/download,University of Texas at Austin,"Particle size, binder content and the post-processing schedule are important parameters
that affect the microstructure, and, hence, the mechanical properties of parts produced using the
indirect selective laser sintering process. 13-93 bioactive glass, with mean particle sizes ranging
from 10 µm to 44 µm, is mixed with different amounts of stearic acid binder to fabricate green
scaffolds. Through the design of the post-processing schedule, the time required for postprocessing the green scaffolds is reduced from the initial 80 hrs to 12 hrs. The compressive
strength varies from 41 MPa for a part with ~60% porosity to 157 MPa for a part with no
designed porosity. Several batches of 13-93 scaffolds are soaked in a simulated body fluid for
different time intervals ranging from 1 week to 6 weeks. The amount of hydroxyapatite formed
and subsequent mechanical properties are provided and discussed.",,,,,,
"['Song, Yong-Ak', 'Park, Sehyung', 'Kwon, Yongsin']",2019-10-09T16:04:49Z,2019-10-09T16:04:49Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76147', 'http://dx.doi.org/10.26153/tsw/3236']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Casting,Effective Cooling Method for Spin Casting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9db5f08e-2acd-412f-932a-4e7ed5ca4bee/download,,"Spin casting has been widely used in prototyping industry as a secondary process to convert
a master model into a functional metal or plastic part. The main problem of the spin casting
process consists in the poor thermal conductivity of silicone rubber as mold material which
leads to a long cooling time between each casting processes and also to a short life time of
mold. To solve this problem, different cooling methods have been developed and compared to
each other experimentally. First, air cooling channel has been integrated into the spin casting
mold to enhance the heat removal. Secondly, the silicone rubber has been mixed with different
metal and ceramic powders to increase its thermal conductivity. The results so far prove an
applicability of the developed cooling methods.",,,,,,
"['Fashanu, O.', 'Murphy, D.', 'Spratt, M.', 'Newkirk, J.', 'Chandrashekhara, K.']",2021-11-30T21:31:06Z,2021-11-30T21:31:06Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90555', 'http://dx.doi.org/10.26153/tsw/17474']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['unit-cell', 'elasticity', 'lattice structures', 'octet-truss', 'selective laser melting']",Effective Elastic Properties of Additively Manufactured Metallic Lattice Structures: Unit-Cell Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fc16870-d5fd-4c7c-82af-ddf940660996/download,University of Texas at Austin,"Lattice structures are lightweight materials, which exhibit a unique combination of properties such
as air and water permeability, energy and acoustic absorption, low thermal conductivity, and
electrical insulation. In this work, unit-cell homogenization was used to predict the effective elastic
moduli of octet-truss (OT) lattice structures manufactured using selective laser melting (SLM).
OT structures were manufactured using a Renishaw AM 250 SLM machine with various relative
densities. Compression test was carried out at strain rate 5 × 10-3 m-1 using an MTS frame. Finite
element analysis was used in the determination of the OT’s effective elastic properties. Results
from the finite element analysis were validated using experiments. It was observed that the finite
element predictions were in good agreement with the experimental results.","This work was funded
by the Department of Energy’s Kansas City National Security Campus which is operated and
managed by Honeywell Federal Manufacturing & Technologies, LLC under contract number DENA0002839.",,,,,
"['Loose, Kai', 'Niino, Toshiki', 'Nakagawa, Takeo']",2019-02-19T19:55:43Z,2019-02-19T19:55:43Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73440', 'http://dx.doi.org/10.26153/tsw/592']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LED', 'MPC']",Effective Mechanisms of Multiple LED Photographic Curing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dabce9a1-7148-41f0-bc50-abaea20ff70b/download,,"Multiple LED Photographic Curing (MPC) has proven capable of drawing cross sections of
three-dimensional objects like printing a sheet of paper. Using raster scanning, however, simultaneously exposing a photopolymer with 1,024 beams of light involves various unknown issues. The
aim of this research work was to examine the formation of individual strings and the connecting
mechanisms between strings and layers. At light power ranging from 19.0 to 30.3flW and at various scan speeds, string formation perpendicular to scan direction differs greatly from that in scan
direction. Curing of plane layers happens by curing strings side-by-side with a constant spacing of
62.5flm.",,,,,,
"['Cook, D.', 'Newbauer, S.', 'Pettis, D.', 'Knier, B.', 'Kumpaty, S.']",2021-10-05T15:03:33Z,2021-10-05T15:03:33Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88388', 'http://dx.doi.org/10.26153/tsw/15327']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['multi-functional components', 'unit-lattice structures', 'thermal conductivities', 'orthosis', 'additive manufacturing', 'orthosis device']",Effective Thermal Conductivities of Unit-Lattice Structures for Multi-Functional Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f31e6774-364f-4b5a-9eba-79c0d0d4ab14/download,University of Texas at Austin,"Approaching the goal of automatically generating optimized multi-functional
components, previously-identified unit-lattice structures are being characterized for their
geometry-dependent, effective, thermal conductivities. This knowledge base will allow for the
definition of low-mass, load-bearing, thermal-management structures. One application is a
wearable power source for a custom, portable, active orthosis. The function of this structure is to
bear mechanical load while dissipating heat from the source, without burning the wearer.
Additive manufacturing affords the capability of fabricating the resultant complex structures.
Current research efforts are using finite-element analysis and physical testing to validate the
characteristic models, and determining the scale dependence of internal-convective-flow
development. Future work will include composites.",,,,,,
"['Hasbrouck, C.R.', 'Bartolai, Joseph', 'Pagan, Darren C.', 'Miller, Simon W.']",2024-03-25T23:43:51Z,2024-03-25T23:43:51Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124342', 'https://doi.org/10.26153/tsw/50950']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', '17-4PH stainless steel', 'thermal history', 'heat treatment']",EFFECTIVENESS OF EX-SITU HEAT TREATMENT OF L-PBF AM 17-4PH STAINLESS STEEL SPECIMENS INTENTIONALLY EXPOSED TO DIFFERENT AS-BUILT THERMAL HISTORIES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2729e662-9e7b-4f12-8c78-977b9f1820e5/download,University of Texas at Austin,"The presented research demonstrates the effectiveness of H900 heat treatment in
eliminating microstructural and mechanical property differences between additively manufactured
17-4PH stainless steel samples of varying thermal histories. For this effort, 17-4PH stainless steel
was manufactured using laser-based powder bed fusion on an EOS M280 machine in two
geometries: ASTM Standard E8 subsize rectangular tensile specimen geometry with thicknesses
of 2mm and 6mm. Thermal histories were manipulated by adding secondary laser passes on each
layer at varying levels of reduced power. All samples were heat treated after the build following
H900 procedures. Mechanical performance was evaluated with uniaxial quasi-static tensile testing
and Vickers microhardness measurements. Metallography was examined qualitatively with optical
and electron microscopy as well as quantitatively through electron backscatter diffraction. No
statistically significant mechanical property or microstructural differences were discovered,
suggesting a successful ex-situ heat treatment.",,,,,,
"['Register, Matthew', 'Priddy, Matthew W.']",2023-01-27T17:50:40Z,2023-01-27T17:50:40Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117347', 'http://dx.doi.org/10.26153/tsw/44228']",eng,2022 International Solid Freeform Fabrication Symposium,Open,WAAM,Effects Due to Variations in Thermal Properties of Maraging Steel for Finite Element Modeling of the WAAM Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ab92b0b7-5d7e-451b-82d3-97453ed78cbd/download,,"Finite element (FE) thermal simulations of the wire arc additive manufacturing (WAAM) process have 
been widely used to predict the temperature history of as-built parts. Temperature-dependent thermal properties 
like density, conductivity, specific heat, and latent heat are required to accurately simulate the solidus to liquidus 
transition seen in the heat affected zone. Current research has shown that thermal properties measured 
experimentally or simulated using material database software can be used for thermal modeling; however, there 
has been no direct comparison shown to determine which is most appropriate for WAAM modeling. The focus 
of this research is to compare the temperature variation of the FE thermal simulations with experimentally 
measured and computer-generated properties for M250 grade maraging steel. The thermal history for thin wall 
builds are compared with differing temperature-dependent thermal properties to examine the relationship between 
thermal properties and history. It was shown that constant values at room temperature result in an increased 
thermal response for WAAM thermal simulations and linearized properties decreased the temperature when both 
were compared with the experimental thermal property inputs. Further work needs to be performed before 
determining the most appropriate source for thermal properties (wrought, wire, as-built, or material database), but 
it can be concluded that the form of material does affect the thermal response for maraging grade 250 steel.",,,,,,
"['Ottemer, Xavier', 'Colton, Jonathan S.']",2019-10-18T14:50:20Z,2019-10-18T14:50:20Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76228', 'http://dx.doi.org/10.26153/tsw/3317']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Epoxy-Based,Effects of Aging on Epoxy-Based Rapid Tooling Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1bc1ef36-df6d-4b98-a7c4-731adbeab18c/download,,"This study shows the effects of aging on epoxy-based rapid tooling materials. Two
epoxy-acrylate resins used for stereolithography and one aluminum powder-filled epoxy used
for the high speed machining of plastic injection molds were selected to investigate their aging
behavior in different environments. Four different conditions, each characterized by a specific
relative humidity, were used to perform a seven week long aging study. Temperature was kept
constant at 30°C. Both stereolithographic resins showed a drop in mechanical properties and in
their glass transition temperatures in wet environments, whereas aging time showed little
influence on these properties. Moisture uptake is mainly responsible for that drop and
coefficients of water diffusion were determined. On the other hand, the aluminum powder-filled
epoxy showed little humidity-dependent drop in mechanical properties and in its glass transition
temperature during aging. This result correlates well with the very low moisture absorption of
this material.",This work has been made possible thanks to the National Science Foundation (DMI9618039) and the Rapid Prototyping and Manufacturing Institute.,,,,,
"['Kriewall, Caitlin S.', 'Sutton, Austin T.', 'Karnati, Sreekar', 'Newkirk, Joseph W.', 'Leu, Ming C.']",2021-11-02T15:00:30Z,2021-11-02T15:00:30Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89820,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['304L', 'stainless steel', 'area fraction', 'part spacing', 'selective laser melting']",Effects of Area Fraction and Part Spacing on Degradation of 304L Stainless Steel Powder in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ce13f34d-5178-4886-9e90-96e15cdcd67b/download,University of Texas at Austin,"In selective laser melting (SLM) systems, a large portion of powder remains
unconsolidated and therefore recycling powder could make SLM more economical. Currently, a
lack of literature exists specifically targeted at studying the reusability of powder. Furthermore,
the definition of powder reusability is complex since powder degradation depends on many factors.
The goal of the current research is to investigate the effects of area fraction and part spacing on
the degradation of 304L powder in SLM. An experimental study was conducted where various
area fractions and part distances were chosen and powder characterization techniques for
determination of particle size distributions, tap and apparent densities, and x-ray diffraction were
employed to track evolving powder properties for the purpose of reuse. The results show that the
recyclability of 304L powder depends on the utilization of the build area causing varying degrees
of particle size coarsening and delta ferrite formation.",,,,,,
"['Andurkar, Mohanish', 'O-Donnell, Valentina', 'Gahl, John', 'Prorok, Bart', 'Keya, Tahmina', 'Harvill, Greyson', 'Thompson, Scott']",2021-12-06T22:51:29Z,2021-12-06T22:51:29Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90705', 'http://dx.doi.org/10.26153/tsw/17624']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'nickel superalloy', 'nuclear radiation damage', 'Vickers microhardness', 'additive manufacturing']",Effects of Build Orientation and Heat Treatment on Neutron Irradiation Hardening in Inconel 625 Fabricated via Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f227329-f912-4c09-99ef-1c8a20e14be2/download,University of Texas at Austin,"Various Inconel 625 coupons fabricated via Laser Powder Bed Fusion (L-PBF) were
neutron irradiated using the inside reflector of the reactor at the University of Missouri Research
Reactor (MURR). Effects of build orientation and heat treatment on neutron-induced hardening
were investigated by inspecting L-PBF samples built vertically or at a 45º angle in the following
heat-treated conditions: as-built (no heat treatment), 700 ºC for 1 hour, 900 ºC for 1 hour, and
1050 ºC for 1 hour. The microhardness results of L-PBF samples before and after neutron
irradiation were compared with traditional wrought Inconel 625. All samples underwent an
irradiation flux of 6.61 x 1013 neutrons/cm²/s for 310 hours for an estimated damage of 0.012 dpa.
Results indicate that as-built L-PBF specimens are less prone to radiation hardening relative to
their wrought counterparts. As-printed diagonal specimens were shown to harden by 8% as
compared to 1.2% hardening in as-printed vertical specimens.",,,,,,
"['Andurkar, Mohanish', 'Prorok, Bart', 'Gahl, John', 'Thompson, Scott']",2024-03-25T23:46:29Z,2024-03-25T23:46:29Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124343', 'https://doi.org/10.26153/tsw/50951']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'x-ray CT', 'porosity measurements', 'pore morphology']",Effects of Build Orientation and Heat Treatment on the Porosity Distribution and Morphology within Inconel 625 Fabricated via Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82089975-1ff6-4146-8fb2-e8c6cd5df93e/download,University of Texas at Austin,"The effects of build orientation, i.e., vertical, or diagonal (45º), and heat treatment on the
porosity characteristics within Inconel 625 (IN625) fabricated via laser powder bed fusion (LPBF) was experimentally investigated. Selected samples were heat treated at 1050 ℃ for 1-hour
to promote evolution of pores. X-Ray Computed Tomography (XCT) was performed on samples
to generate three-dimensional porosity maps. Volume Graphics (VG) software was used to inspect
and quantify porosity distributions. Results indicate that build orientation and heat treatment
influence measured porosity count. As-built (no heat treatment) sample microstructure was
observed to have lower porosity count when compared to heat-treated samples. The vertically built
sample was observed to have lower porosity relative to its diagonally built counterpart. The
porosity morphology or diameter was observed to vary after heat treatment. On the other hand, the
sphericity of pores was not affected by different build orientation and heat treatment.",,,,,,
"['Motaparti, Krishna P.', 'Taylor, Gregory', 'Leu, Ming C.', 'Chandrashekhara, K.', 'Castle, James', 'Matlack, Mike']",2021-10-28T14:22:01Z,2021-10-28T14:22:01Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89647,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['compression properties', 'build parameters', 'ULTEM 9085', 'fused deposition modeling']",Effects of Build Parameters on Compression Properties for ULTEM 9085 Parts by Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/09236221-0f00-41b0-9ea1-49e6a37e3bbb/download,University of Texas at Austin,"It has been observed by various researchers that parts fabricated by the Fused Deposition
Modeling (FDM) process have anisotropic properties. The research presented in the present
paper was aimed to study the compression properties of FDM parts and to comprehend their
dependence on build parameters. In this study Ultem 9085 was used as the material to fabricate
both solid and sparse-build coupons with variations in build direction, raster angle and air gap. A
full factorial experimental design was used to study the individual and combined effects of these
build parameters on the mechanical properties of the coupons. The mechanical properties studied
include compressive yield strength, compressive modulus, compressive strength/mass ratio, and
compressive modulus/mass ratio. Besides the obtained test data, qualitative observation and
reasoning was used to help understand how the compression properties are affected by the build
parameters.",,,,,,
"['Munaganuru, Sai Sri Nidhi', 'Elenchezian, Muthu Ram Prabhu', 'Vadlamudi, Vamsee', 'Shaik, Rauhon Ahmed', 'Adluru, Hari Kishore', 'Raihan, Rassel', 'Reifsnider, Kenneth']",2021-11-11T16:02:21Z,2021-11-11T16:02:21Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90227', 'http://dx.doi.org/10.26153/tsw/17148']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['build parameters', 'mechanical properties', 'di-electrical properties', 'additive manufacturing']",Effects of Build Parameters on the Mechanical and Di-Electrical Properties of AM Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc32c38c-580e-486c-b7fc-e1ecd1aa9282/download,University of Texas at Austin,"Additive manufacturing (AM) revolutionized many industries, i.e., Automotive,
Biomedical, Aerospace and Defense. As opposed to traditional manufacturing methods, a part is
manufactured layer by layer from 3D CAD models in AM. Though the vision of AM is impressive,
there are many challenges that are hindering the widespread use of these complex parts. One of
the challenges in these materials is defects grow and their orientation during the manufacturing
process. In this paper we are going to investigate the effect of Build Parameters and their effects
on the mechanical and electrical properties of the additively manufactured heterogeneous material
system. We will study the electrical properties to find out the material state of additively
manufactured part.",,,,,,
"['Fan, Foxian', 'Soares, Nicholas', 'Jalui, Sagar', 'Isaacson, Aaron', 'Savla, Aditya', 'Manogharan, Guha', 'Simpson, Tim']",2021-12-07T19:04:52Z,2021-12-07T19:04:52Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90759', 'http://dx.doi.org/10.26153/tsw/17678']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['centrifugal disc finishing', 'AM surface finishing', 'AM gears', 'surface roughness', 'CT roughness measurements', 'powder bed fusion']",Effects of Centrifugal Disc Finishing for Surface Improvements in Additively Manufactured Gears,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1bda4710-1aaf-4af4-9f61-f99b7a9f309b/download,University of Texas at Austin,"Additive Manufacturing (AM) is well suited to rapidly produce complex and customized
geometries economically for low production runs. However, there is an inherent need for post-AM machining and surface finishing in most metal AM applications. Centrifugal Disc Finishing
(CDF) is a media-based mass finishing process that can be employed to improve surface finish of
external surfaces of AM parts with complex geometry. This original study aims to understand the
influence of CDF processing conditions on Ti64 gear teeth fabricated via Powder Bed Fusion
(PBF). A detailed statistical analysis is conducted to analyze the effectiveness of CDF to
improve surface roughness of different build surfaces of the AM gear teeth. In addition, both
contact profilometer and X-ray Computer Tomography (CT) techniques are applied to evaluate
its effectiveness to measure CDF and AM surface finishing. Findings from this study on CDF of
gear AM will benefit metal AM community by better understanding the impact of CDF
processing conditions for surface improvements in mass finishing of metal AM parts.",,,,,,
"['Fuentes, F.', 'Gallardo Jr., A.', 'Martinez, J.', 'Bullman, J.', 'Foyos, J.', 'Mendelson, M.', 'Noorani, R.', 'Fritz, B.']",2019-10-22T18:17:24Z,2019-10-22T18:17:24Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76333', 'http://dx.doi.org/10.26153/tsw/3422']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Cryogenic,Effects of Cryogenic Aging on a Rapid Prototyped (RP) Polymer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/802364f2-948a-47d9-af0c-1c9260db8a31/download,,"Little research has been done on the post-processing (aging) of rapid prototyped (RP)
polymers at temperatures below 123K (–238˚F). Test specimens of RP thermosetting resin
(DSM-Somos 8110) were fabricated and cryogenically aged from 10-25 hours. The tensile
strength and impact toughness were measured. This work will study the effect of cryogenic
aging on yield strength of Somos 8110. This paper will also discuss our interpretation of the data
based on fractography.","The work was funded by an NSF Grant under Research Experiences for Undergraduates
(REU).",,,,,
"['Jackson, J.', 'Chapple, G.', 'Do, J.', 'Zhuang, X.', 'Bulman, J.', 'Foyos, J.', 'Mendelson, M.', 'Noorani, R.', 'Fritz, B.']",2019-11-21T18:42:37Z,2019-11-21T18:42:37Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78565', 'http://dx.doi.org/10.26153/tsw/5621']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Prototyping Materials,Effects of Cryogenic Processing on Rapid Prototyping Materials (DSMSomos-8110 and DuraForm PA),Conference paper,https://repositories.lib.utexas.edu//bitstreams/186d87c6-d505-4cd3-b358-b85d589f47d4/download,,"This research investigates the effects of cryogenic processing on the properties of rapid
prototyped materials. Not much research has been done on the post-processing (aging) of rapid
prototyped (RP) polymers at temperatures below 159K (–173˚F). Test specimens of RP
thermoplastic resin DSM-Somos 8110 and DuraformPA Nylon were fabricated and
cryogenically aged from 5-30 hours. The tensile strength and impact toughness were measured.
The goal of this work was to study the effect of cryogenic aging on yield strength and ductility.
This research investigated (1) the cryogenic aging of DSM-Somos 8110 and DuraformPA Nylon,
(2) the effects of controlled ramp-downs/ups on the ultimate and tensile strengths of samples, (3)
the experimental methods, and (4) the analysis and interpretation of the data.","Part of this work was funded by a NSF Grant under Research Experiences for
Undergraduates.",,,,,
"['Fan, K.M.', 'Cheung, W.L.']",2019-09-20T18:23:38Z,2019-09-20T18:23:38Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75926', 'http://dx.doi.org/10.26153/tsw/3025']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Sintering,Effects of Cu and SiO2 on Laser Sintering of Polycarbonate 110,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11f10eaa-20ff-47b3-b318-3b00c160c0a6/download,,"Additives of different thermal properties, Cu and SiO2 (amorphous and crystalline), were blended to polycarbonate (PC) powder to modify its heat transfer properties and fusion behavior during laser sintering. The blends were sintered under different energy densities of the laser beam to produce mono-layer films. The surface morphology and the thickness of the films were
studied. When sintering under the same condition, the composite films which contained a high content of Cu powder exhibited a more porous surface structure. This was caused by the increased heat loss because the Cu powder has a higher thermal conductivity. Also, the solid Cu particles would hinder the flow of the molten polymer, resulting in a low degree of fusion. For a given Cu powder content, reducing its particle size gave a more porous surface structure and a smaller thickness of the sintered films. This was probably due to a more even distribution of the fine Cu particles, which increased the heat loss and reduced the effective amount of energy for fusion. On the other hand, fine SiO2 and quartz powders caused degradation of the polymer
because of the increased energy dissipation near the film surface and poor heat transfer properties of the additives comparing with Cu.",,,,,,
"['Majewski, C. E.', 'Zarringhalam, H.', 'Hopkinson, N.']",2020-03-10T17:04:53Z,2020-03-10T17:04:53Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80230', 'http://dx.doi.org/10.26153/tsw/7249']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Differential Scanning Calorimetry,Effects of Degree of Particle Melt and Crystallinity in SLS Nylon-12 Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/118e0bfa-74e8-4d49-b646-8c3d96ad9c02/download,,"Differential Scanning Calorimetry (DSC) traces for SLS Nylon-12 parts display two
distinct melt peaks, which have been related to the presence of both melted and crystallised
regions, and un-melted particle cores within the part. The relative proportions of each region are
defined by the term ‘Degree of Particle Melt’ (DPM), and have a large effect on the mechanical
properties of a part. This paper demonstrates that the % crystallinity of SLS Nylon-12 parts is
dependent on the DPM. Crucially, research has also shown that the trends for some tensile
properties (notably Tensile Strength and Young’s Modulus) change once full melting is
complete.",,,,,,
"['Shrestha, Rakish', 'Nezhadfar, P. Dastranjy', 'Masoomi, Mohammad', 'Simisiriwong, Jutima', 'Phan, Nam', 'Shamsaei, Nima']",2021-11-10T23:08:47Z,2021-11-10T23:08:47Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90205', 'http://dx.doi.org/10.26153/tsw/17126']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'thermal simulation', 'additive manufacturing', 'laser-based powder bed fusion', 'L-PBF']",Effects of Design Parameters on Thermal History and Mechanical Behavior of Additively Manufactured 17-4 PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02b026f1-7940-438e-b232-4acf7a9e39ea/download,University of Texas at Austin,"In this study, the effects of part size on thermal history and mechanical properties of
additively manufactured 17-4 PH stainless steel were investigated under monotonic tensile and
strain-controlled fatigue loadings. Two sets of specimens were machined from square rods and
oversized specimens, which were fabricated using a laser bed powder fusion (L-PBF) process, to
introduce variation in specimen geometry and consequently thermal history. Monotonic tensile
tests were conducted at a strain rate of 0.001 s-1
. Fully-reversed (Rε = -1), strain-controlled fatigue
tests were performed at 0.003 and 0.0035 mm/mm, and varying test frequency to maintain a
constant average strain rate in all tests. Experimental results indicated minimal effect of specimen
geometry on the tensile properties of L-PBF 17-4 PH SS, which were also found to be comparable
to the wrought material. On the other hand, some influence of specimen geometry on fatigue
behavior was observed. Specimens machined from square rods exhibited slightly higher fatigue
resistance as compared to specimens machined from oversized specimens. Furthermore, thermal
simulations demonstrated higher bulk heating in specimens machined from oversized specimens
as compared to those from square rods, which indicated the effect of part geometry on thermal
history experienced by the fabricated part.",,,,,,
"['Lares, J.', 'Godinez, D.', 'Arrieta, E.', 'Medina, F.', 'Wicker, R.', 'Gradl, P.', 'Katsarelis, C.']",2024-03-25T23:02:19Z,2024-03-25T23:02:19Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124333', 'https://doi.org/10.26153/tsw/50941']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['NASA HR-1', 'direct energy deposition', 'deposition parameters', 'microstructure']","EFFECTS OF DIFFERENT PARAMETERS ON DED HR-1 ON LOW CYCLE FATIGUE, TENSILE STRENGTH, AND MICROSTRUCTURE",Conference paper,https://repositories.lib.utexas.edu//bitstreams/fac45921-e0ff-445b-b11d-cdb3cddc4bc1/download,University of Texas at Austin,"NASA HR1 alloy is an iron-nickel based material designed by NASA and derived from A286
and JBK-75 alloys. At extreme conditions, NASA HR1 possess high strength, high fatigue resistance,
and high resistance to corrosion and hydrogen embrittlement. The main applications include
structural components and liquid rocket engine nozzles with internal cooling channels. NASA has
produced HR1 using vacuum induction melting (VIM), a considerably expensive fabrication method.
Aimed to explore other more affordable and accessible manufacturing methods, HR1 specimens were
fabricated under different parameters using Laser-Powder Directed Energy Deposition (LP-DED) and
were heat treated through stress relief, homogenization, solution treatment and aging. The feasibility
of this AM process was investigated by evaluating mechanical and microstructural analysis on
specimens. This work finalizes with discussion and remarks on tensile and low-cycle fatigue
properties and its relationship with microstructural features.",,,,,,
"['George, Mitchell J.', 'Crawford, Richard H.']",2021-10-04T19:55:01Z,2021-10-04T19:55:01Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88329', 'http://dx.doi.org/10.26153/tsw/15268']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'medical sterilization', 'nylon parts', 'dry heat sterilization', 'surgical tooling', 'bone matrices']",The Effects of Dry Heat Sterilization on Parts Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a94a355b-488b-4d66-b8b4-7371b76a4d1a/download,University of Texas at Austin,"Selective Laser Sintering (SLS) is a manufacturing process that can build arbitrarily shaped parts
without part specific tooling. Its advantages have been employed in many different fields, one of
these being medical surgery. Currently, SLS is limited in medical applications as a pre-operative
modeling tool. For SLS manufacturing to progress in areas like compliant surgical tooling and
patient specific bone matrices, concurrent work is needed to investigate the effects of medical
sterilization on SLS materials. This paper presents the results of sterilization experiments on SLS
parts built from nylon 11. To simulate the process of introducing tools into a sterile environment,
these specimens were subjected to multiple rounds of dry heat sterilization. Changes to the
dimensions, tensile strength and flexibility were recorded and analyzed. It was found that the
specimens’ dimensions remained relatively constant. Both the tensile modulus and the flexural
modulus decreased as the sterilization cycles progressed. The tensile modulus decreased by 25%
and the flexure modulus decreased by 19% after ten rounds of sterilization.",,,,,,
"['Hagen, Deborah', 'Kovar, Desiderio', 'Beaman, Joseph J.']",2021-11-09T21:03:12Z,2021-11-09T21:03:12Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90166', 'http://dx.doi.org/10.26153/tsw/17087']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['electric field', 'laser scanning', 'selective laser sintering', 'ceramic powder', 'yttria-stabilized zirconia']",Effects of Electric Field on Selective Laser Sintering of Yttria-Stabilized Zirconia Ceramic Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d567f84d-6052-4d11-b75e-4379fa8c1437/download,University of Texas at Austin,"Selective laser sintering (SLS) of ceramic material is particularly challenging. High
sintering temperatures and slow sintering kinetics of ceramic material combined with poor
thermal shock resistance have resulted in cracking when ceramics are sintered to full density one
layer at a time. This work investigates the use of an electric field applied simultaneously with
laser scanning to accelerate the kinetics of sintering to produce a multi-layer SLS ceramic part.
Ceramic sintering rates have been shown to increase by orders of magnitude during conventional
furnace-based flash sintering, in which electric field applied simultaneously with furnace
heating. In this work, we investigate the effects of an electric field applied during SLS
processing of yttria-stabilized zirconia ceramic.",,,,,,
"['Andurkar, M.', ""O'Donnell, V."", 'Keya, T.', 'Prorok, B.C.', 'Gahl, J.', 'Thompson, S.M.']",2023-03-30T16:04:30Z,2023-03-30T16:04:30Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117695', 'http://dx.doi.org/10.26153/tsw/44574']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'Nickel Superalloy', 'Vickers Microhardness', 'Radiation  Embrittlement']",Effects of Fast Neutron Irradiation on the Microhardness of Inconel 625 and Inconel 718 Fabricated via Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90692cb0-34b9-4e37-b78a-912445aeec28/download,,"The demand for advanced materials in constructing next generation nuclear reactors 
has intensified the need to explore additive manufacturing (AM) processes as an alternate 
means of fabricating components. In this study, Inconel 625 (IN625) and Inconel 718 (IN718) 
samples fabricated using Laser Powder Bed Fusion (L-PBF) were irradiated using fast 
neutrons. Samples investigated included as-printed and heat-treated at either 700, 900, or 1050 
℃ for 1 hour to understand the impact of heat treatment on any neutron irradiation hardening. 
Wrought IN625 and IN718 samples were also inspected for experimental control. All samples 
were irradiated for 7 weeks resulting in a total fluence 2.74x10

15 neutrons/cm

2. To quantify 
radiation damage, the Vickers microhardness was measured before and after fast neutron 
irradiation. Results show that the IN718 samples experienced less change (-2.5 to 3.24 %) in 
microhardness. On the other hand, IN625 samples underwent more (0.9 to 7.21%) change in 
microhardness post fast neutron irradiation.",,,,,,
"['Burkert, T.', 'Fischer, A.']",2021-10-20T22:08:50Z,2021-10-20T22:08:50Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89375,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'Direct Metal Laser Sintering', 'Lasercusing', 'Maraging Steel', 'heat balance', 'mechanical properties', 'energy input', 'preheat temperature', 'void', 'defect']",The Effects of Heat Balance on the Void Formation within Marage 300 Processed by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/398d648b-d4fd-40ff-af87-7474059eb078/download,University of Texas at Austin,"This contribution shows the results of a study that was conducted on the effects of varying
selective laser melting (SLM) process parameters on the formation of microstructural voids
within a maraging steel (type: Marage 300, 1.2709, AMS6514). Due to the large number of
process variables the most influential parameters were identified first. These were energy input
resulting from scanning speed, hatch distance, and layer thickness as well as the preheating of the
platform. On the basis of the variation of these parameters the most abundant voids were
identified and characterized by metallographic investigations. Subsequently tensile tests derived
information about the influence of such voids on the mechanical properties. Based on these
analyses the reasons for the generation of such voids are discussed followed by strategies in order
to prevent them. This allowed for the well-aimed optimization of the processing parameters
resulting in a nearly void-free SLM processing of such maraging steel parts.",,,,,,
"['Keya, T.', ""O'Donnell, V."", 'Lieben, J.', 'Romans, A.', 'Harvill, G.', 'Andurkar, M.', 'Gahl, J.', 'Thompson, S.M.', 'Prorok, B.C.']",2021-12-06T22:54:26Z,2021-12-06T22:54:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90706', 'http://dx.doi.org/10.26153/tsw/17625']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['heat treatment', 'neutron irradiation', 'Inconel 625', 'microstructure', 'microhardness', 'laser-powder bed fusion', 'L-PBF']",Effects of Heat Treatment and Fast Neutron Irradiation on the Microstructure and Microhardness of Inconel 625 Fabricated via Laser-Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/01b3261f-159d-4c8f-81a8-529a024962d6/download,University of Texas at Austin,"The microstructure of Inconel 625 fabricated via Laser-Powder Bed Fusion (L-PBF) was
investigated in as-printed and heat-treated conditions. The very high cooling rates inherent to the
L-PBF process generally result in fine microstructures and complex residual stress fields which
requires annealing to reduce stress and tailor the microstructure to obtain the desired mechanical
properties. Inconel 625 alloy, a nickel-based superalloy, continues to be a common material
employed with the L-PBF process. The unique microstructure produced by the L-PBF process and
different phases introduced by different heat treatment processes require investigation to facilitate
the material’s wide range of applications. This paper investigates the influence of heat treatments
at 700°C, 900°C and 1050°C for one hour on the microstructure and microhardness of the L-PBF
parts. The parts were irradiated using ‘fast’ neutrons in University of Missouri Research Reactor
Center (MURR). The microhardness before and after radiation are also compared.",,,,,,
"['Cullom, Tristan', 'Hartwig, Troy', 'Brown, Ben', 'Johnson, Kevin', 'Blough, Jason', 'Barnard, Andrew', 'Landers, Robert', 'Bristow, Douglas', 'Kinzel, Edward']",2021-11-15T22:35:53Z,2021-11-15T22:35:53Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90298', 'http://dx.doi.org/10.26153/tsw/17219']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['build plate', 'coupling', 'modal analysis', 'frequency response function', 'selective laser melting']",Effects of Identical Parts on a Common Build Plate on the Modal Analysis of SLM Created Metal,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c198cf13-e563-4fc4-a5fc-55d2e35d9eb7/download,University of Texas at Austin,"The frequency response of parts created with Additive Manufacturing (AM) is a function of not
only process parameters, powder quality, but also the geometry of the part. Modal analysis has the
potential to evaluate parts by measuring the frequency response which are a function of the
material response as well as the geometry. A Frequency Response Function (FRF) serves as a
fingerprint of the part which can be validated against the FRF of a destructively tested part. A
practical scenario encountered in Selective Laser Melting (SLM) involves multiple parts on a
common build plate. Coupling between parts influences the FRF of the parts including shifting the
resonant frequencies of individual parts in ways that would correspond to changes in the material
response or geometry. This paper investigates the influence of the build plate properties on the
coupling phenomena.","This work was funded by the Department of Energy’s Kansas City National
Security Campus which is operated and managed by Honeywell Federal Manufacturing
Technologies, LLC under contract number DE-NA0002839.",,,,,
"['Nigam, Aman', 'Tai, Bruce L.']",2021-12-07T18:51:47Z,2021-12-07T18:51:47Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90756', 'http://dx.doi.org/10.26153/tsw/17675']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['fiber-reinforced polymer', 'fused filament fabrication', 'FFF', 'hybrid process', 'polishing', '3D printing', 'surface roughness']",Effects of In-Situ Mechanical and Chemical Polishing on Surface Topography of Additively Manufactured Fiber-Reinforced Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8fd121c8-285d-4dc2-97a5-1f3e113d2b02/download,University of Texas at Austin,"Additive manufacturing of fiber-reinforced polymers (FRPs) has revolutionized fused filament
fabrication (FFF) by producing polymeric parts with enhanced mechanical properties. However,
FFF suffers from poor surface quality and dimensional accuracy, particularly for FRPs, due to their
abrasive and rheological nature. This examines an in-situ polishing scheme for FRPs in the FFF
configuration. Glass-fiber-reinforced Nylon was used as the study material. Three polishing
schemes, mechanical, chemical, and a combined thereof, were adopted along with various
parameters in each case. The results show significant surface improvements in all cases, and the
combined process can further reduce the Ra value to around 2 μm and the dimensional error to 0.2
mm and less. The combined process also enhances surface uniformity (i.e., similar Ra in all
directions). In particular, with the combined approach, the in-situ polishing scheme is expected to
improve the quality of 3D printed FRPs significantly.",,,,,,
"['Masoomi, Mohammad', 'Thompson, Scott M.', 'Shamsaei, Nima', 'Bian, Linkan']",2021-10-26T18:16:11Z,2021-10-26T18:16:11Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89548,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['temperature gradients', 'directed energy deposition', 'Ti-6Al-4V', 'residual stress']",Effects of Inter-Layer Time Interval on Temperature Gradients in Direct Laser Deposited Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1500151-387e-4bb8-9f97-b504b43711c5/download,University of Texas at Austin,"Parts fabricated via additive manufacturing (AM) methods are prone to experiencing high
temperature gradients during manufacture resulting in internal residual stress formation. In the
current study, a numerical model for predicting the temperature distribution and residual stress in
Directed Energy Deposited (DED) Ti–6Al–4V parts is utilized for determining a relationship
between local part temperature gradients with generated residual stress. Effects of time-interval
between successive layer deposits, as well as layer deposition itself, on the temperature gradient
vector for the first and each layer is investigated. The numerical model is validated using
thermographic measurements of Ti-6Al-4V specimens fabricated via Laser Engineered Net
Shaping® (LENS), a blown-powder/laser-based DED method. Results demonstrate the
heterogeneity in the part’s spatiotemporal temperature field, and support the fact that as the part
number, or single part size or geometry, vary, the resultant residual stress due to temperature
gradients will be impacted. As the time inter-layer time interval increases from 0 to 10 second,
the temperature gradient magnitude in vicinity of the melt pool will increase slightly.",,,,,,
"['Fulcher, Ben', 'Leigh, David K.']",2021-10-07T15:50:20Z,2021-10-07T15:50:20Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88487', 'http://dx.doi.org/10.26153/tsw/15421']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['laser power', 'laser sintering', 'laser window', 'laser distribution', 'degradation']",Effects of Laser Window Degredation on Laser Power and Distribution in Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/29ccf6ba-4fb7-45f2-b375-8ae7c1f29098/download,University of Texas at Austin,"Laser power is a key parameter in the laser sintering (LS) process, and tight control on
laser power is necessary to produce quality parts with desirable mechanical properties.
Unfortunately, temperature limitations hinder real-time monitoring and feedback of laser power
within the process chamber. Therefore, in order to maintain consistent laser power during an LS
build, the laser window, which provides a barrier between the processing chamber and the laser
housing, must remain clean throughout the build. However, material outgassing leads to the
buildup of condensation on the window, thereby reducing the amount of energy imparted to the
powder bed. The buildup of condensation also necessitates frequent cleaning of the laser window
and significantly reduces its life. Thus, laser window replacement is a large source of cost in a
production environment. To compensate for the loss of laser power through the window, current
practice is to steadily increase the laser power at the laser source during the build. This practice
can be largely inaccurate, as it is difficult to predict the loss of laser power through the window
at various stages in a given LS build. Thus, to achieve consistent mechanical properties in this
manner, a trial and error-based approach is used. The study presented in this paper aims to
characterize laser power and distribution for various levels of laser window degradation. In
addition, methods to reduce or eliminate the buildup of condensation on the laser window are
explored in an effort to improve the consistency of part quality, as well as to reduce maintenance
requirements and costs.",,,,,,
"['Carrion, Patricio', 'Imandoust, Aidin', 'Simsiriwong, Jutima', 'Shamsaei, Nima']",2021-11-11T15:10:32Z,2021-11-11T15:10:32Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90214', 'http://dx.doi.org/10.26153/tsw/17135']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'failure mechanisms', 'mutliaxial fatigue', 'titanium']",Effects of Layer Orientation on the Multiaxial Fatigue Behavior of Additively Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d1088aba-472f-4728-9e25-9c4568711ec3/download,University of Texas at Austin,"Additive manufacturing (AM) allows for fabrication of components with complex
geometries that cannot be fabricated using conventional manufacturing techniques. These
components are often subjected to multiaxial stress states due to their typically complex design
accompanied by residual stresses and/or multiaxial external loading. Therefore, understanding the
fatigue behavior of AM materials under multiaxial-type loadings is necessary for ensuring reliable
in-service component performance. In this study, the effects of layer orientation on the multiaxial
fatigue behavior of Ti-6Al-4V fabricated via a laser-powder bed fusion (L-PBF) process was
investigated. Tubular thin-walled multiaxial specimens were fabricated in vertical and diagonal
orientations with respect to the build plate. Specimens were tested under axial, torsional, in-phase
axial/torsional, and 90° out-of-phase axial-torsional cyclic loadings. Upon failure, the crack
orientation of vertical and diagonal specimens was correlated to the type of loading, which
illustrated the failure mechanism of L-PBF Ti-6Al-4V and justified the variations in the fatigue
lives of specimens.",,,,,,
"['Wang, Zhaogui', 'Fang, Zhenyu', 'Smith, Douglas E.']",2021-12-07T17:50:28Z,2021-12-07T17:50:28Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90735', 'http://dx.doi.org/10.26153/tsw/17654']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['fiber orientation state', 'polymer deposition', 'material properties', 'mechanical properties', 'large area additive manufacturing']",Effects of Local Fiber Orientation State on Thermal-Mechanical Behaviors of Composite Parts Made by Large Area Polymer Deposition Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/70d09119-a475-4a68-9c60-38fa3fafe94a/download,University of Texas at Austin,"Short carbon fiber enhances the dimensional stability and material strength of composite
parts created via large area polymer deposition additive manufacturing, which has been used for
rapid fabrications of large-dimension composite parts and tooling. Nevertheless, the flow-induced
fiber orientation formed during the material extrusion and deposition leads the deposited
composites exhibit non-homogeneous thermal-mechanical behaviors. This study evaluates the
fiber orientation state of a 20 wt.% CF-PEI composite fabricated by polymer deposition using the
fully coupled flow/orientation approach. The material properties are computed by considering the
deposited bead as heterogeneous segments with different local fiber orientation states. The
heterogeneous thermal conductivity and expansion coefficient exhibit maximum local differences
of 29% and 21%, respectively. The orientation-homogenized material properties are implemented
to the finite element simulation for a large area additive manufacturing process of a single bead
and notable differences are seen between results computed by employing the homogenous and
heterogeneous properties.",,,,,,
"['Zhang, Ying', 'Jariwala, Amit', 'Rosen, David W.']",2021-10-19T20:24:23Z,2021-10-19T20:24:23Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89332,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Exposure Controlled Projection Lithography', 'process planning', 'post-processing', 'oxygen inhibition']",Effects of Oxygen Inhibition and Post-Processing on Exposure Controlled Projection Lithography Process Accuracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/331fbefe-39a6-4547-85ce-016b54be775c/download,University of Texas at Austin,"Exposure Controlled Projection Lithography (ECPL) is a mask-projection
stereolithography process which can be used to create micro lenses on flat or curved substrates.
In the ECPL process, the ultraviolet light patterned by the dynamic mask passes through a
transparent substrate to cure the photopolymer resin to a certain shape. The dimensions of the
part can be controlled by the exposure time and functional pixels in the dynamic mask. In this
paper, a modified process planning method is presented with the considerations of postprocessing and oxygen inhibition, which can vary part dimensions significantly. The effects of
post-processing and oxygen inhibition are studied and characterized. The accuracy of the lateral
and vertical dimensions of the cured part are improved by the revised method. Experimental
validation is obtained by fabricating samples using the ECPL system.",,,,,,
"['Lim, J.H.', 'Khan, N.A.']",2021-11-30T20:20:48Z,2021-11-30T20:20:48Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90534', 'http://dx.doi.org/10.26153/tsw/17453']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['particle size distribution', 'surface finish', 'Inconel 625', 'selective laser melting']",Effects of Particle Size Distribution on Surface Finish of Selective Laser Melting Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/860839a0-b54e-4e96-896e-5eb722a183c8/download,University of Texas at Austin,"Metal parts produced by Selective Laser Melting (SLM) usually exhibit poor surface
finish compared to conventional manufacturing processes. There is a growing need for parts to
have good surface quality in the as-built condition to minimise post-processing costs and reduce
lead time. There are many studies done on the effects of processing parameters on surface finish
but very little on the influence of powder characteristics. This study aims to investigate the
effects of Particle Size Distribution (PSD) on surface finish of AM parts by printing coupons
with Inconel 625 powders of varying PSD. It was found that roughness of internal surfaces was
mainly caused by the presence of partially sintered particles. Whilst a smaller particle mean
size and wider particle size range are preferred for better surface finish, a powder that is too
fine may result in poor flowability affecting its processability in terms of layering and powder
bed quality.",,,,,,
"['Obielodan, J.O.', 'Stucker, B.E.']",2021-09-29T14:11:46Z,2021-09-29T14:11:46Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88177', 'http://dx.doi.org/10.26153/tsw/15118']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic consolidation', 'post processing heat treatment', 'titanium material', 'aluminum material', 'bond quality', 'mechanical strength', 'Ti/Al3003']",Effects of Post Processing Heat Treatments on the Bond Quality and Mechanical Strength of Ti/Al3003 Dual Materials Fabricated using Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4cb691fc-01e1-415a-86ec-9a55a029eb89/download,University of Texas at Austin,"The interface between layers in ultrasonically fabricated parts is often poor for desirable
material combinations, resulting in relatively low bond strength. This makes these fabrications
unsuitable for structural applications. This work discusses a study of the effects of post
processing heat treatment of ultrasonically consolidated titanium and aluminum dual-material
specimens. The shear strengths of as-deposited specimens as well as heat treated ones were
tested. The results show that there is significant improvement of the strengths of post processed
specimens over the as-fabricated ones. The improvement is as a result of interactions of the base
materials across the interfacial boundaries at elevated temperatures, leading to stronger bonds.
The study highlights the role of post processing for improving the mechanical properties of
ultrasonically consolidated structures.",,,,,,
"['Koju, Naresh', 'Hermes, Jonah', 'Paul, Sumit', 'Saghaian, Sayed Ehsan', 'Yang, Li']",2023-02-24T14:49:39Z,2023-02-24T14:49:39Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117525', 'http://dx.doi.org/10.26153/tsw/44405']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Lightweight features', 'thin struts', 'powder feedstock', 'powder bed fusion', 'porosity', 'microstructure', 'strength']",The effects of powder feedstock and process parameters on the material characteristics of Ti6Al4V thin strut features fabricated by laser powder bed fusion additive manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aa616203-8e72-44dc-9047-f8fdf7d50404/download,,"In this work, three different types of Ti6Al4V powder feedstock of different particle size 
ranges (fine, medium, and coarse) were utilized to fabricate thin strut lightweight features using 
laser powder bed fusion additive manufacturing (L-PBF-AM) using different process parameter 
settings. Thin strut features of varying dimensions from 0.1mm to 0.5mm were fabricated. The 
resulting sample sets allow for the analysis of the compound powder feedstock-process-
geometry-material (PPG-M) characteristics for lightweight features fabricated by L-PBF-AM, 
which have not been previously explored. Various material characteristics were experimentally 
determined and analyzed, including success rate, geometry quality, porosity, pore size, grain 
size, and mechanical properties of the lightweight thin strut samples. The results clearly 
demonstrated the significance of the compound PPG-M relationships for lightweight structures, 
which calls for further studies to “re-establish” the knowledge base for L-PBF-AM materials at 
small dimension scales.",,,,,,
"['Nezhadfar, Pooriya Dastranjy', 'Soltani-Tehrani, Arash', 'Sterling, Amanda', 'Tsolas, Nicholas', 'Shamsaei, Nima']",2021-11-10T23:23:36Z,2021-11-10T23:23:36Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90206', 'http://dx.doi.org/10.26153/tsw/17127']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['17-4 PH stainless steel', 'laser powder bed fusion', 'powder characterization', 'powder recycling', 'mechanical properties', 'tensile behavior']",The Effects of Powder Recycling on the Mechanical Properties of Additively Manufactured 17-4 PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e6b45358-89d3-4a0e-9f2f-50684d29dc5a/download,University of Texas at Austin,"The booming interest in Additive Manufacturing (AM), is seeing a rising number of
industries and research entities adopting this technology into their manufacturing practices. Of
particular interest is Laser Powder Bed Fusion (L-PBF) process, a common AM method for
fabricating metallic components. However, one obstacle is the high cost of powder feedstock. A
popular tactic to offset this cost is to reuse the powder between prints, but there is no in-depth
understanding of how the powder feedstock may change or affect the mechanical properties of the
produced parts. By incorporating unique powder/part characterization methods, this study
quantifies the rheological properties of continually recycled 17-4 precipitation hardening (PH)
stainless steel (SS) powder through successive printing of mechanical test specimens. The AM
specimens are subjected to tensile tests, to correlate mechanical behavior to changing powder
quality, including particle size/shape distribution, flowability, and density.",,,,,,
"['Soltani-Tehrani, Arash', 'Yasin, Mohammad Salman', 'Shao, Shuai', 'Shamsasei, Nima']",2021-12-06T23:08:52Z,2021-12-06T23:08:52Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90710', 'http://dx.doi.org/10.26153/tsw/17629']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'L-PBF', 'powder recycling', 'Ti-6Al-4V', 'particle size distribution', 'PSD', 'location dependency', 'packing state', 'powder flowability']",Effects of Powder Reuse and Spatial Location Dependency on the Powder Characteristics and Defect Structure of Additively Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13d67006-9662-4b26-8c0e-1d754de6d26b/download,University of Texas at Austin,"In laser powder bed fusion additive manufacturing (L-PBF AM), different powder characteristics
including particle size and morphology may yield different packing states and thus different defect
content in the resulting parts. As the powder is spread by the recoater, the packing state may not
be uniform on the powder bed, giving rise to location-dependent part performance. In addition, as
the powder is reused (a common practice in AM industry), its characteristics continuously evolve,
causing the defect content to change from build to build. This study aims to investigate the effects
of powder reuse and part location on powder characteristics as well as the defect structure of the
parts. Results indicate powder reuse in an L-PBF system may reduce the number of defects in the
as-fabricated parts due to the superior packing state of reused powder. Part density was also found
to be location-dependent, with more defects near the gas outlet.",,,,,,
"['Gu, Hengfeng', 'Gong, Haijun', 'Dilip, J.J.S.', 'Pal, Deepankar']",2021-10-13T19:20:54Z,2021-10-13T19:20:54Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88766', 'http://dx.doi.org/10.26153/tsw/15700']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['powder variation', 'metallic powder', 'Selective Laser Melting', 'Ti6Al4V', 'microstructure', 'tensile strength']",Effects of Powder Variation on the Microstructure and Tensile Strength of Ti6Al4V Parts Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/57ba353e-7ea4-4158-afda-6989d2c1cd41/download,University of Texas at Austin,"Metallic powders are used as raw materials in the Selective Laser Melting (SLM) process. These
metal powders are typically available from more than one powder vendor. Even when powders
have the same nominal chemical compositions, powders produced by different companies
typically result in different powder particle size distributions and morphologies. These powder
differences result in different powder bed thermophysical properties, which affect how the powder
melts and solidifies. This paper studies the effect of powder variation on the microstructure and
tensile strength of as-built SLM Ti6Al4V parts. Ti6Al4V powders from different vendors were
used to fabricate parts via SLM. Powder characteristics, such as particle size distribution,
morphology, and flowability, were obtained. Powder bed densities and thermal conductivities were
measured and compared. The microstructures and tensile strengths were investigated by standard
metallographic and tensile testing methods. Based on the experimental results, a correlation
between the powder characteristics and part properties are discussed.",,,,,,
"['Akhtar, SP', 'Wright, CS', 'Youseffi, M']",2020-02-12T15:36:33Z,2020-02-12T15:36:33Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79940', 'http://dx.doi.org/10.26153/tsw/6966']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,The Effects of Pre-Alloyed Steels Powder Compositions on Build Quality in Direct Metal Laser Re-Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b999c053-9596-47dd-95ca-dfde5182358c/download,,,,,,,,
"['Mahtabi, MohammadBagher', 'Yadollahi, Aref', 'Stokes, Ryan', 'Young, Joseph', 'Doude, Haley', 'Priddy, Matthew W.', 'Bian, Linkan']",2023-01-19T16:07:00Z,2023-01-19T16:07:00Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117247', 'http://dx.doi.org/10.26153/tsw/44128']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Build interruption', 'Additive manufacturing (AM)', 'Failure location', 'Al-Si-10Mg', 'Ti- 6Al-4V']",Effects of Process Interruption During Laser Powder Bed Fusion on Microstructural and Mechanical Properties of Fabricated Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c112176d-e2f3-4e1b-84ac-67a3a449f5d7/download,,"Despite appropriate planning, various incidents can stop the additive manufacturing (AM) 
process of metals and cause build interruption, such as power outage, lack of powder feedstock, 
and/or shielding gas to mention a few. Due to the layer-by-layer nature of fabrication, an 
interruption to the AM process can be resumed from the location where the stoppage occurred. 
However, build interruption may adversely affect the structural integrity of the fabricated parts, by 
causing localized failure near the interruption location. This study aims to investigate the influence 
of build interruption during the laser powder bed fusion (LPBF) process on the microstructural 
and mechanical properties of Ti-6Al-4V and Al-Si-10Mg specimens. For the Ti-6Al-4V 
specimens, results indicate that tensile failures near the interruption location are most likely to 
happen for non-heat-treated specimens in the as-built surface condition. Whereas for the Al-Si-
10Mg specimens, the failure location is more influenced by the prolonged stoppage and air 
exposure.",,,,,,
"['Mahtabi, MohammadBagher', 'Yadollahi, Aref', 'Stokes, Ryan', 'Young, Joseph', 'Doude, Haley', 'Priddy, Matthew W.', 'Bian, Linkan']",2023-01-26T14:17:02Z,2023-01-26T14:17:02Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117303', 'http://dx.doi.org/10.26153/tsw/44184']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Build interruption', 'Additive manufacturing', 'Failure location', 'Al-Si-10Mg', 'Ti- 6Al-4V']",Effects of Process Interruption During Laser Powder Bed Fusion on Microstructural and Mechanical Properties of Fabricated Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44170140-71d3-435a-aa8e-706e1a139c22/download,,"Despite appropriate planning, various incidents can stop the additive manufacturing (AM) 
process of metals and cause build interruption, such as power outage, lack of powder feedstock, 
and/or shielding gas to mention a few. Due to the layer-by-layer nature of fabrication, an 
interruption to the AM process can be resumed from the location where the stoppage occurred. 
However, build interruption may adversely affect the structural integrity of the fabricated parts, by 
causing localized failure near the interruption location. This study aims to investigate the influence 
of build interruption during the laser powder bed fusion (LPBF) process on the microstructural 
and mechanical properties of Ti-6Al-4V and Al-Si-10Mg specimens. For the Ti-6Al-4V 
specimens, results indicate that tensile failures near the interruption location are most likely to 
happen for non-heat-treated specimens in the as-built surface condition. Whereas for the Al-Si-
10Mg specimens, the failure location is more influenced by the prolonged stoppage and air 
exposure.",,,,,,
"['Huang, Wenpu', 'Wang, Zemin', 'Yang, Jingjing', 'Yang, Huihui', 'Zeng, Xiaoyan']",2021-11-10T23:06:23Z,2021-11-10T23:06:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90204', 'http://dx.doi.org/10.26153/tsw/17125']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'process parameters', 'heat treatment', 'microstructure', 'mechanical properties']",Effects of Process Parameters and Heat Treatment on the Microstructure and Mechanical Properties of Selective Laser Melted Inconel 718,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea24d57c-b513-4f88-8eaa-0597b9f5f924/download,University of Texas at Austin,"In this study, Inconel 718 superalloy was fabricated by selective laser melting
(SLM) and solution treated at 980-1230 ℃subsequently. The process window was firstly set up
based on the density of the samples. Samples were fabricated using various parameters within the
process window to investigate the effects of process parameters on microstructure and mechanical
properties. The average dendrite arm spacing and the volume fraction of Laves phase raise along
with the increasing energy input. However, no distinct difference of tensile properties was found
under parameters in the process window. Interdendritic Laves phase decreases with the solution
temperature, while the grain size has the opposite trend. Finally, the solution temperature was fixed
at 1080 ℃to dissolve Laves phases and obtain fine grains. After solution + aging heat treatment,
the tensile strengths and ductility all exceed the wrought Inconel 718.",,,,,,
"['Bontha, S.', 'Brown, C. J.', 'Klingbeil, N. W.', 'Gaddam, D. R.', 'Kobryn, P. A.', 'Fraser, H. L.', 'Sears, J. W.']",2020-02-12T15:16:08Z,2020-02-12T15:16:08Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79935', 'http://dx.doi.org/10.26153/tsw/6961']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solidification Microstructure,Effects of Process Variables and Size Scale on Solidification Microstructure in Laser-Based Solid Freeform Fabrication of Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d2fec261-3ff6-4473-8cf8-cf59e9285fc1/download,,,,,,,,
"['Gray IV, R. W.', 'Baird, D. G.', 'Bohn, J. H.']",2018-12-05T20:32:09Z,2018-12-05T20:32:09Z,1997,Mechanical Engineering,doi:10.15781/T24B2XR11,http://hdl.handle.net/2152/71414,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'Thermotropic liquid crystalline polymers']",Effects of Processing Conditions on Prototypes Reinforced with TLCPs for Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1484ef81-4ea6-419e-9e3c-87dbfe6beada/download,,"Polypropylene (PP) composite strands, reinforced with thermotropic liquid crystalline
polymers (TLCPs), were generated using a novel dual extrusion process which allowed for
the use of a TLCP with a significantly higher melting temperature than that of the PP.
Pregenerated TLCPtpp microcomposite strands were reprocessed using a second novel
process to produce a wen-controned monofilament composite for use in a FDM 1600
rapid prototyping system in order to build complex geometries. Uniaxial parts were built
to determine the effect of differing material compositions and processing temperatures, in
order to develop an oPerating window for the optimal mechanical properties. By
adjusting the lay down pattern of orientable materials, the final mechanical properties of
the part could be engineered independent ofthe material. To understand the effect ofthe
reprocessing steps on the pregenerated microcomposites, the final mechanical properties
ofthe monofilament composite were compared with those ofthe pregenerated strands.",,,,,,
"['Hrabe, Nikolas', 'Kircher, Ryan', 'Quinn, Timothy']",2021-10-07T15:02:25Z,2021-10-07T15:02:25Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88472', 'http://dx.doi.org/10.26153/tsw/15409']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['electron beam melting', 'titanium alloy', 'Ti-6Al-4V', 'characterization', 'orientation', 'mechanical properties']",Effects of Processing on Microstructure and Mechanical Properties of Ti-6Al-4V Fabricated using Electron Beam Melting (EBM): Orientation and Location,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2800f141-e075-4558-8353-30788794955a/download,,"Electron beam melted (EBM) titanium alloy (Ti-6Al-4V) samples were built and
characterized (qualitative prior-β grain size, quantitative α lath thickness, monotonic tensile,
Vickers microhardness) to determine the effect of location and orientation on microstructure and
properties. Samples of vertical orientation, compared to horizontal, were found to have 30%
lower elongation. Orientation within the x-y plane as well as location were found to have less
than 3 % effect on mechanical properties, and it is possible a second order effect of thermal mass
contributed to these results.",,,,,,
"['Gong, Haijun', 'Rafi, Khalid', 'Starr, Thomas', 'Stucker, Brent']",2021-10-11T20:28:46Z,2021-10-11T20:28:46Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88631', 'http://dx.doi.org/10.26153/tsw/15565']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'Electron Beam Melting', 'Ti-6Al-4V', 'processing parameter', 'marginal parameters', 'part defect']",The Effects of Processing Parameters on Defect Regularity in Ti-6Al-4V Parts Fabricated By Selective Laser Melting and Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1961575d-60e4-4b15-bbe3-e074d2bfb298/download,University of Texas at Austin,"Processing parameter has an important effect on Selective Laser Melting (SLM) and
Electron Beam Melting (EBM) processes. Defects are easily formed by deviating from optimized
processing parameters. This study purposely fabricated Ti-6Al-4V specimens with defects by
varying process parameters from the factory default settings in both SLM and EBM equipment.
Specimen’s density was measured based on the Archimedes method for estimating porosity.
Microscopy of specimen’s top surface were observed to compare melt pool and overlap. “Marginal
Parameters” is identified to describe the processing parameters which are capable of fabricating
specimens with certain porosity. As a result, a correlation between defect regularity and marginal
parameters has been established. The effect of marginal parameters on the melt pool is discussed
to explain defect formation.",,,,,,
"['Basak, Amrita', 'Kalaitzidou, Kyriaki', 'Das, Suman']",2021-11-02T14:35:32Z,2021-11-02T14:35:32Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89811,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'scanning laser epitaxy', 'SLE', 'nickel-base', 'superalloys', 'CMSX-4', 'mechanical testing']",Effects of Processing Parameters on the Mechanical Properties of CMSX-4® Additively Fabricated through Scanning Laser Epitaxy (SLE),Conference paper,https://repositories.lib.utexas.edu//bitstreams/44239336-105c-45f8-aceb-8e03c570ee9b/download,University of Texas at Austin,"The work aims to characterize the effects of processing parameters on the mechanical properties
of CMSX-4® fabricated using a laser-powder bed fusion (LPBF)-based additive manufacturing
(AM) process, scanning laser epitaxy (SLE). The laser power, the scan speed, and the number of
repeat scans are varied in SLE. These parameters are combined to define a new measure such as
the energy density. Microstructures of the samples are investigated using optical microscopy and
scanning electron microscopy. Uniaxial tension tests are performed on samples in longitudinal
direction and relevant data is extracted.","This work is sponsored by the Office of Naval Research
through grant N00014-14-1-0658.",,,,,
"['Masoomi, Mohammad', 'Thompson, Scott M.', 'Shamsaei, Nima', 'Haghsenas, Meysam']",2021-11-08T21:56:11Z,2021-11-08T21:56:11Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90052', 'http://dx.doi.org/10.26153/tsw/16973']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['scanning', 'residual stress', 'temperature distribution', 'laser powder bed fusion', 'L-PBF', 'Ti-6Al-4V']",Effects of Scanning Strategy on Residual Stress Formation in Additively Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f285202d-ac2d-48c3-a108-c8744e82a073/download,University of Texas at Austin,"Parts fabricated via directed energy additive manufacturing (AM) can experience very high, localized
temperature gradients during manufacture. These temperature gradients are conducive to the formation
of a complex residual stress field within such parts. In the study, a thermo-mechanical model is employed
for predicting the temperature distribution and residual stress in Ti-6Al-4V parts fabricated using laser-powder bed fusion (L-PBF). The result is utilized for determining a relationship between local part
temperature gradients with generated residual stress. Using this numerical model, the effects of scan
patterns are investigated.",,,,,,
"['Jost, Elliott', 'Miers, John', 'Robinson, Aron', 'Moore, David', 'Saldana, Christopher']",2021-11-17T23:59:16Z,2021-11-17T23:59:16Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90362', 'http://dx.doi.org/10.26153/tsw/17283']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['spatial energy distribution', 'defects', 'fractures', 'stainless steel 316L', 'scanning electron microscopy', 'laser powder bed fusion', 'LPBF']",Effects of Spatial Energy Distribution on Defects and Fracture of LPBF 316L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bfcdf007-1ab5-4261-b1a0-d0a8e2daa24b/download,University of Texas at Austin,"Measures of energy input and spatial energy distribution during laser powder bed fusion
additive manufacturing have significant implications for the build quality of parts, specifically
relating to formation of internal defects during processing. In this study, scanning electron
microscopy was leveraged to investigate the effects of these distributions on the mechanical
performance of parts manufactured using laser powder bed fusion as seen through the fracture
surfaces resulting from uniaxial tensile testing. Variation in spatial energy density is shown to
manifest in differences in defect morphology and mechanical properties. Computed tomography
and scanning electron microscopy inspections revealed significant evidence of porosity acting as
failure mechanisms in printed parts. These results establish an improved understanding of the
effects of spatial energy distributions in laser powder bed fusion on mechanical performance.",,,,,,
"['Kircher, R.S.', 'Christensen, A.M.', 'Wurth, K.W.']",2021-09-28T20:27:20Z,2021-09-28T20:27:20Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88175', 'http://dx.doi.org/10.26153/tsw/15116']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['microstructures', 'mechanical properties', 'additive manufacturing', 'Ti6Al4V alloys', 'Electron Beam Melting']",The Effects of Specimen Dimensions on the Mechanical Behavior of EBM Produced Ti6Al4V Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f2c6fe66-db6f-486d-b51e-209022d957b4/download,University of Texas at Austin,"There are several published studies investigating the microstructures and mechanical
properties obtained during additive manufacturing of Ti6Al4V alloys utilizing the Electron Beam
Melting (EBM) technique. These studies have concentrated on conventional testing coupon sizes
and configurations which allowed for a direct comparison to the properties of conventionally
produced Ti6Al4V alloys. One of the many benefits of the EBM process is that it allows the
manufacturer to produce components in sizes and configurations unachievable by conventional
methods. It becomes important to understand and verify the microstructures and mechanical
performance of these smaller components in a manufacturing environment, requiring the use of
non‐conventional testing configurations. This paper presents case-studies involving the
production and testing of non-standard samples and how these samples compare to conventional
E8 testing coupons. Differences in mechanical performance were observed and are most likely
due to the unique characteristics of EBM produced materials.",,,,,,
"['Kletetzka, I.', 'Gawlikowicz, R.', 'Schmid, H.-J.']",2023-03-29T16:24:21Z,2023-03-29T16:24:21Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117679', 'http://dx.doi.org/10.26153/tsw/44558']",eng,2022 International Solid Freeform Fabrication Symposium,Open,laser sintering,Effects of Spherical Fillers on the Processability and Mechanical Properties of PA613 and PP-Based Laser Sintering Dry Blends,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e0bce04-badf-4597-8a3f-a34b86173668/download,,"Polymer materials filled with particles may show substantially altered mechanical 
properties. Therefore, it is an important aim to be able to tailor the mechanical properties of LS 
components by adding fillers and thus to create new application areas for additively manufactured 
components. In this work, the influences of spherical fillers on the processing properties and the 
resulting mechanical properties of laser-sintered components are investigated. For this purpose, 
micro glass spheres, hollow glass bubbles and mineral spheres are dry blended to the matrix 
polymers polyamide 613 and polypropylene with filling ratios of 20 and 40 vol%. First, relevant 
properties of the blends, such as powder flowability, thermal behavior and melt viscosity, are 
investigated. Based on the results, processing parameters are then developed for the laser sintering 
(LS) process and the mechanical properties of the components are investigated.",,,,,,
"['Soltani-Tehrani, Arash', 'Yasin, Mohammad Salman', 'Shao, Shuai', 'Shamsaei, Nima']",2021-12-06T23:02:16Z,2021-12-06T23:02:16Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90708', 'http://dx.doi.org/10.26153/tsw/17627']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Ti-6Al-4V', 'stripe width', 'L-PBF', 'process parameters']",Effects of Stripe Width on the Porosity and Mechanical Performance of Additively Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb479358-df67-427b-aa0b-66ec6917b9a4/download,University of Texas at Austin,"In laser powder bed fusion (L-PBF) additive manufacturing, parts are manufactured in a
layer-by-layer pattern. In each layer, cross-sections can be scanned with or without partitioning by
the laser, which are commonly known as “stripe” and “meander” patterns, respectively. Under the
two scanning strategies, the thermal history experienced by the part can be considerably different.
Accordingly, defect distribution, microstructure, and mechanical properties may be affected. In
this study, two sets of Ti-6Al-4V specimens were fabricated using L-PBF: in one set, the tracks
were partitioned in 5-mm stripes, while in the other set, they were partitioned at 100 mm resulting
in no stripe seams in the cross-section. It was found that altering the stripe width can considerably
affect the laser penetration depth, the defect content, and consequently fatigue performance.
However, tensile strength was not much sensitive to changing the stripe width.",,,,,,
"['Li, Jie', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2021-10-19T20:15:05Z,2021-10-19T20:15:05Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89330,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['temperature', 'extrusion-based additive manufacturing', 'ceramic parts', 'freeform extrusion fabrication']",Effects of Temperature on Aqueous Freeform Extrusion Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/385f5472-05bd-428e-a5f6-1769dc24836a/download,University of Texas at Austin,"An experimental study was conducted to investigate the effect of temperature on ceramic
parts produced by paste extrusion based additive manufacturing followed by sintering. A
computer-controlled gantry system equipped with a piston extruder was used to extrude aqueous
alumina paste. The system includes a temperature control subsystem that allows for freeform
extrusion fabrication inside a low-temperature (<0°C) chamber. It can also be used for fabricating
parts on a hot plate at ambient or higher temperatures (≥20°C). Test specimens were fabricated
from aqueous aluminum pastes at -20°C in the low-temperature chamber and also on the hot plate
at 40°C. The minimum angles achievable by these two processes for part fabrication, without use
of support material, were compared. Also compared were the relative density and mechanical
properties of the parts obtained after sintering. Microstructures were examined via scanning
electron microscopy in order to obtain a deeper understanding of the effect of fabrication
temperature.",,,,,,
"['Wang, Xin', 'Lough, Cody S.', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Kinzel, Edward C.']",2021-11-09T14:51:33Z,2021-11-09T14:51:33Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90086', 'http://dx.doi.org/10.26153/tsw/17007']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['spatial sampling resolution', 'thermal camera', 'temperature monitoring', 'feature extracts', 'selective laser melting']",Effects of Thermal Camera Resolution on Feature Extraction in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/043033c9-f7d8-46b5-85b0-4e6f506e2e8d/download,University of Texas at Austin,"Selective Laser Melting (SLM) is a common additive manufacturing process which uses a
laser energy source to fuse metal powder layer by layer. Engineering properties and
microstructure are related to the part’s thermal history. It is important to measure the thermal
history in-situ to qualify parts and provide the sensing which is necessary for process control. A
common measurement tool for this purpose is a thermal camera that records the thermal emission
of the part’s surface.
This study investigates the effects of spatial sampling resolution of thermal cameras when
monitoring the temperature in SLM processes. High-fidelity simulation of an SLM process is
used to quantify the effects of the camera’s sampling in space. Next, the effect that spatial
resolutions have on feature extraction, namely peak temperature and melt pool morphology, is
investigated by applying feature extraction methodologies to the down-sampled simulation data.
Finally, some methods of refining the down-sampled data are applied and their effects are
discussed.",,,,,,
"['Soltani-Tehrani, Arash', 'Lee, Seungjong', 'Sereshk, Mohammad Reza Vaziri', 'Shamsaei, Nima']",2021-11-30T21:39:12Z,2021-11-30T21:39:12Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90558', 'http://dx.doi.org/10.26153/tsw/17477']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'laser beam powder bed fusion', 'LB-PBF', 'stainless steels', 'stiffness', 'bone implants']",Effects of Unit Cell Size on the Mechanical Performance of Additive Manufactured Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e0cf212-2864-489f-a937-fe9f85515878/download,University of Texas at Austin,"Lattice structures are generated through the repetition of smaller structures, defined as unit
cells. These structures are popular alternatives for bone implants due to the potential to adjust the
stiffness. However, in some applications, there are volume and mass constraints that cannot be
exceeded. Therefore, to match the lattice structure’s stiffness to that of the natural bone, unit cell
sizes should be altered. In this study, the effects of different unit cell sizes, on the compression
behavior of lattice structures fabricated from 316L stainless steel (SS) via laser beam powder bed
fusion (LB-PBF) are studied through finite element analysis (FEA) while the volume and mass are
kept constant and results of which, are validated by experiments. It was found that energy
absorption capability and stiffness of lattice structures can increase with decreasing the size while
the volume and mass are kept constant. The lattice structure with smaller unit cell dimensions
tolerated a relatively higher maximum force for the same amount of displacement.",,,,,,
"['Snelling, Dean', 'Blount, Heather', 'Forman, Charles', 'Ramsburg, Kelly', 'Wentzel, Andrew', 'Williams, Christopher', 'Druschitz, Alan']",2021-10-11T22:57:21Z,2021-10-11T22:57:21Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88677', 'http://dx.doi.org/10.26153/tsw/15611']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', 'indirect 3D printing', 'metal casting', 'sand casting']",The Effects on 3D Printed Molds on Metal Castings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dca0142c-8b06-46b6-b15e-192db2a5457b/download,University of Texas at Austin,"Additive manufacture of sand molds via binder jetting enables the casting of complex metal
geometries. Various material systems have been created for 3D printing of sand molds;
however, a formal study of the materials’ effects on cast products has not yet been conducted. In
this paper the authors investigate potential differences in material properties (microstructure,
porosity, mechanical strength) of A356 – T6 castings resulting from two different commercially
available 3D printing media. In addition, the material properties of cast products from traditional
“no-bake” silica sand is used as a basis for comparison of castings produced by the 3D printed
molds.",,,,,,
"['Choi, S.H.', 'Zhu, W.K.']",2021-09-23T21:55:53Z,2021-09-23T21:55:53Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88032', 'http://dx.doi.org/10.26153/tsw/14973']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['concurrent toolpaths', 'multi-material prototypes', 'layered manufacturing', 'Two-phase Overlap Query Algorithm', 'Immediate Fabrication Algorithm']",Efficient concurrent toolpath planning for multi-material layered manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8f192b84-54d3-4985-9849-6e8e4b15e7b0/download,,"This paper proposes an algorithm for planning efficient concurrent toolpaths to reduce the
build-time of fabricating multi-material prototypes by layered manufacturing. The algorithm first
sorts and partitions slice contours into hierarchical families of specific materials to enhance
concurrent tool movements. It then detects overlapping of parametric tool envelopes with a
“Two-phase Overlap Query Algorithm” to avoid potential tool collisions. Finally, it plans
concurrent movements with an “Immediate Fabrication Algorithm” (IFA) to enhance fabrication
efficiency by reducing idle time of tools. The algorithm is being implemented in a multi-material
virtual prototyping system. It can be adapted for control of physical fabrication of multi-material
prototypes when appropriate hardware becomes available.",,,,,,
"['Li, Fangzhi', 'Wang, Zemin', 'Zeng, Xiaoyan']",2021-11-02T13:51:52Z,2021-11-02T13:51:52Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89802,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['multi-laser beam', 'selective laser melting', 'Ti6Al4V', 'microstructure', 'mechanical property']",Efficient Fabrication of Ti6Al4V Alloy by Means of Multi-Laser Beam Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56ef7b24-2607-45f5-9e9b-c3579daeca12/download,University of Texas at Austin,"A self-developed four-laser beam selective laser melting (SLM) system was used to fabricate
Ti6Al4V alloy samples in this study. The relative density, micro-hardness and mechanical
properties of all isolated processing areas were compared under optimized processing
parameters to ensure the consistency of this system. Microstructures in overlap areas are
dominated by columnar grains along the building direction and matensitic needles αˊ inclined
at about ± 45° to the building direction, which are similar with those in isolated areas.
Mechanical properties in overlap areas are also not inferior to those in isolated areas. The
results prove the feasibility to fabricate large-scale components with a uniform microstructure
and mechanical property by this SLM system. By the use of four lasers, this system can
provide a high building rate of 80 cm3/h.",,,,,,
"['Tan, S.J.', 'Zhang, X.', 'Ding, L.P.', 'Zhang, Y.C.']",2021-12-06T23:36:32Z,2021-12-06T23:36:32Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90719', 'http://dx.doi.org/10.26153/tsw/17638']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['layer construction', 'toolpaths', 'periodic cellular structures', 'selective laser melting']",An Efficient Layer Construction Method to Generate Accurate Printing Toolpaths of Periodic Cellular Structures for Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b27d905-c662-4b70-80b3-0865c885d423/download,University of Texas at Austin,"Limited by stereolithography file format, current data processing in additive
manufacturing (AM) processing chain is time-consuming and has a loss of model
precision in data transformation. However, both the CAD software and AM machine
accept the input of more convenient and high-precision mathematical curve expressions.
A predefined curved scanning pattern can be achieved in a galvanometer scanning
system of selective laser melting (SLM) process, which can improve the scanning
accuracy and efficiency for the shapes that can be represented by mathematical functions,
e.g., circle. Therefore, this study proposes a layer construction-based method to directly
generate the toolpaths for cellular structure with large file size. To demonstrate the
proposed method, a case study on the toolpath generation for a flame arrestor element
with a large quantity of curved fine channels, is presented. Compared with the
conventional printing preparation methods, the proposed method reduces up to 90% of
the total preparation time and achieves higher quality toolpaths.",,,,,,
"['Li, C.', 'Liu, J.F.', 'Guo, Y.B.']",2021-10-26T18:26:23Z,2021-10-26T18:26:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89552,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'distortion', 'multiscale simulation', 'additive manufacturing']",Efficient Multiscale Prediction of Cantilever Distortion by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f22eaa2a-e788-40b6-8bb2-2e834b564615/download,University of Texas at Austin,"Large tensile residual stress is one major issue for metal components made by selective laser
melting (SLM). Residual stress is induced by non-uniform heat input, which leads to part
distortion and detrimentally affects product performance. The conventional single track
simulation method is not feasible to predict the distortion of a macro part since it demands an
exceedingly long computational time. The coupling multiphysics phenomenon during the SLM
process further complicates this issue. In this study, a temperature-thread multiscale modeling
approach has been developed to predict part distortion of a twin cantilever. An equivalent body
heat flux calculated from the micro scan model was imported as the “temperature-thread” to the
subsequent layer hatch model. Then the hatched layer with temperature field can be used as a
basic unit to build up the macro part. The temperature history and residual stress fields during the
SLM process were predicted. And the distortion of twin cantilever was calculated with a
reasonable accuracy compared to the experimental data.",,,,,,
"['Xu, Nancy', 'Tutum, Cem C.']",2021-11-02T20:43:46Z,2021-11-02T20:43:46Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89893,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['surrogate-based sampling', 'selective laser sintering', 'process parameters', 'tensile strength', 'optimization']",Efficient Sampling for Design Optimization of an SLS Product,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a1e1475-d3a5-4db2-9b8b-3e22dc091ec0/download,University of Texas at Austin,"In this work an efficient constrained surrogate-based sampling algorithm is implemented
to optimize Selective Laser Sintering (SLS) process parameters for maximizing the tensile
strength of a tensile specimen. Two variations of the algorithm have been implemented and
tested on a Farsoon HT251P machine using (polyamid) PA3300 polymer powder. The algorithm
is based on building a statistical predictive model of the objective response (i.e., maximization of
tensile strength), aggregating the constraint function (i.e., limited amount of warping), in an
iterative manner by simultaneously improving the accuracy of the predictive model as well as
searching for the optimum set of process parameters. The difference in two algorithmic
variations is the number of samples to update at each iteration. While the first method is based on
a single sample update, the latter searches for multiple simultaneous updates to let the
manufacturer try several potentially good sets of parameters in the same machine to eventually
speed up the experimental evaluation procedure.",,,,,,
"Bingham, G.A.",2021-10-05T19:00:02Z,2021-10-05T19:00:02Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88409', 'http://dx.doi.org/10.26153/tsw/15348']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'textile structures', '3D modeling']",Efficient Three Dimensional Modelling of Additive Manufactured Textile Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/311c5b9b-48f2-4ebc-9f37-243be447af22/download,University of Texas at Austin,"Textile structures realised by Additive Manufacturing (AM) techniques have received
increasing attention during the previous decade. Due to their potential to significantly
improve upon both the geometric complexity and functionality available from conventional
fibre-based textiles, AM textiles present a serious opportunity to design and develop novel
solutions for conventional and high-performance textile applications. AM textiles also
provide the capability to produce net-shape textile artefacts and allow the development of
personalised, high-performance textiles from a variety of materials currently being processed
by AM technologies.
While the motivation exists for the wider-scale adoption of these novel structures,
practical access to an efficient three dimensional (3D) modelling strategy limits their
applications. The research presented here discusses the issues surrounding the 3D modelling
of complex AM textiles and discusses dedicated methodologies developed for the generation
of their conformal data. The research culminates with a robust methodology for the
generation of AM textile apparel data suitable for manufacture by AM techniques.",,,,,,
"['Yuan, Mengqi', 'Bourell, David']",2021-10-06T22:47:31Z,2021-10-06T22:47:31Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88466', 'http://dx.doi.org/10.26153/tsw/15403']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'part bed thermal gradients', 'infrared camera']",Efforts to Reduce Part Bed Thermal Gradients During Laser Sintering Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8b3bdb33-a402-4aa9-932f-c82a240633c5/download,University of Texas at Austin,"Part bed surface thermal gradients (x-y plane) are usually present in laser sintering (LS)
fabricators. The purpose of this study was to investigate various means to reduce these
thermal gradients. Several experiments were conducted using a FLIR™ infrared camera to
examine the thermal profile of the part bed during the LS operation. Experiments included
thermal profile characterization of the part bed with different nitrogen shielding gas flow rates,
assessment of the proper experimental settings, and a temperature profile record of the part bed
from the warm-up to the cool-down stage. A series of experiments were conducted using the
laser as a heat source to preheat part bed surface cold spots to decrease the thermal gradients,
which effect was limited by the natural low thermal conductivity of nylon 12 powder and large
heat convection. Moreover, manifolds were mounted below the piston to provide warm
nitrogen down draft flow during the LS operation.",,,,,,
"['Kinsella, M. E.', 'Lilly, B.', 'Carpenter, B.', 'Cooper, K.']",2020-02-17T15:09:38Z,2020-02-17T15:09:38Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80006', 'http://dx.doi.org/10.26153/tsw/7031']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Static friction coefficients,Ejection Forces and Friction Coefficients from Injection Molding Experiments Using Rapid Tooling Inserts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d1279abe-2575-4659-a16e-f9d9ca9eb8b5/download,,"Experiments have been performed with injection mold inserts made using solid freeform
fabrication processes in an effort to further study such applications for economic production of
small quantities of parts. Static friction coefficients were determined for HDPE and HIPS against
P-20 steel, sintered LaserForm ST-100, and stereolithography SL 5170 using the ASTM D 1894
standard. Injection mold inserts were constructed of the same three materials and were used to
inject cylindrical parts using HDPE and HIPS. Ejection forces were measured, and a model was
used to calculate ejection forces and apparent coefficients of static friction. Statistical analyses
were used to determine the effects of packing time, cooling time and packing pressure on
ejection force for the three insert types. This paper compares experimental and calculated
ejection forces, compares standard friction test results to calculated apparent coefficients of
friction, summarizes the statistical results, and comments on the feasibility of using rapid tooled
inserts for injection molding.",,,,,,
"['Jangha, Sundiata K.', 'Rosen, David W.']",2019-03-12T16:46:44Z,2019-03-12T16:46:44Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73600', 'http://dx.doi.org/10.26153/tsw/742']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Injection Molding', 'Rapid Tooling']",An Ejection Mechanism Design Method for AIM Tools,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9610b4bf-9e15-4b9c-ab38-d477c3b90d60/download,,"One of the key advantages of AIM tooling is time savings when producing small batch
production quality parts. However, designing suitable ejection mechanisms is becoming a
bottleneck. There are two goals of this paper. First, a model is presented that effectively
characterizes the stresses on the mold core and part during injection molding. Second, a method
is described for ejection system design. Our approach consists of a combination of analytical,
computational, and physical experiments. The ejection system design method will first determine
the feasibility of ejection for a particular part geometry, then will determine the number, sizes,
and locations of ejector pins. Each phase of the method will be formulated into a Compromise
Decision Support Problem, a multi-objective optimization problem formulation. An example will
be presented to provide an idea of the robustness and the limitations of the method. Preliminary
results indicate that this methodology is sound for a simple geometry.",,,,,,
"['Mao, Q.', 'Coutris, N.', 'Fadel, G.M.']",2021-10-26T19:03:17Z,2021-10-26T19:03:17Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89558,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['elastic model', 'plastic model', 'Johnson-Cook model', 'ultrasonic additive manufacturing']",An Elasto/Plastic Model of the Ultrasonic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50377983-a44b-4300-a08d-7e9d1d2fde3c/download,University of Texas at Austin,"Ultrasonic additive manufacturing (UAM) is a solid-state fabrication process that utilizes
ultrasonic energy to bond metal foils layer by layer. It has been shown that bond formation is
closely related to the plastic deformation of the material at the bonding interface. As a result, a
material model is necessary to characterize the elastic and plastic deformation of material under
UAM conditions. The existing material models for UAM suffer from the following issues: 1) the
models are established based on experimental data of a material different from the material used
in UAM. 2) The models have not fully accounted for the influential factors in UAM. Therefore, a
new material model is established by modifying the Johnson-Cook model which is known to be
simple but effective to capture plasticity at elevated temperature and high strain rate. The model is
based on experiments carried out on aluminum 6061-T6 which has been extensively used in the
ultrasonic additive manufacturing. Ultrasound-induced effects including strain hardening, strain
rate hardening, acoustic softening, and thermal softening are considered in the model. In addition
to plasticity, the bond formation/plastic deformation is also profoundly affected by the dynamics
of the built feature which has not been considered in combination with plasticity in the existing
studies. As a result, a UAM model is established in which both the mechanical and dynamic effects
are taken into account. The model is shown to characterize well the plastic deformation at the
bonding interface both qualitatively and quantitatively by comparing its predictions with
experimental observations.",,,,,,
"['Tate, J.S.', 'Brushaber, R.P.', 'Danielsen, E.', 'Kallagunta, H.', 'Navale, S.V.', 'Arigbabowo, O.', 'Shree, S.', 'Yaseer, A.']",2021-11-18T16:27:02Z,2021-11-18T16:27:02Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90416', 'http://dx.doi.org/10.26153/tsw/17337']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['annealing temperature', 'electrical properties', 'mechanical properties', 'polyamide 6', 'nanographene platelets', 'fused filament fabrication']",Electrical and Mechanical Properties of Fused Filament Fabrication of Polyamide 6 / Nanographene Filaments at Different Annealing Temperatures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e858050-8fa0-4493-ab61-d5f281b028c3/download,University of Texas at Austin,"Polyamide 6 (PA 6) nanographene composites are viable engineered nanocomposite
materials with high potential for electrostatic discharge applications. This can be attributed to the
ability of the nanographene particles in reducing the electrical resistivity of the parent polyamide
6 and in turn creating a conductive network for a controllable discharge of static electricity. In
addition, PA 6 nanographene composites can also exploit the good mechanical properties of the
parent polyamide 6, a structural thermoplastic ideal for 3D printing via fused filament fabrication
(FFF). Hence, 3, 5, and 7 wt.% of NGP were blended with PA6 using co-rotating twin screw
extruder to produce 1.75mm diameter for FFF using Lulzbot TAZ 6 3D printer. Scanning
Electron Microscopy (SEM) was used to evaluate the degree of exfoliation of the nanographene
and tensile and electrical resistivity test samples were manufactured via fused filament
fabrication. The polyamide 6 nanographene composites were further subjected to annealing
treatment at 80ºC, 140ºC, 200ºC and a comparison study was carried out on the observed tensile
properties and electrical resistivity values of both annealed and not annealed treated.",,,,,,
"['Bagehorn, S.', 'Wehr, J.', 'Nixon, S.', 'Balastrier, A.', 'Mertens, T.', 'Maier, H.J.']",2021-11-08T21:43:01Z,2021-11-08T21:43:01Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90049', 'http://dx.doi.org/10.26153/tsw/16970']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['electropolishing', '3D SurFin', 'Ti-6Al-4V', 'surface morphology', 'fatigue performance', 'laser beam melting']",Electrochemical Enhancement of the Surface Morphology and the Fatigue Performance of Ti-6Al-4V Parts Manufactured by Laser Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f415fb8e-34d6-43f9-8d34-759df6353de0/download,University of Texas at Austin,"In the course of the industrialization of the Additive Manufacturing (AM) process of
metallic components, the surface finish of the final parts is a key milestone. ‘As-built’ AM
surfaces feature a high initial surface roughness (i.e. Ra > 10 µm), which often exceeds the
specification for technical applications. In order to apply AM for highly stressed and cyclically
loaded components, the as-built surface roughness needs to be reduced. Since conventional
surface finishing processes as machining or blasting often show a limited applicability to
complex shaped AM parts, an enhanced electrolytic polishing process was developed
(3D SurFin®). Within the present study, Ti-6Al-4V AM plates and fatigue samples were
produced in a powder bed laser beam system. The enhanced electrolytic polishing process led to
a significant roughness decrease of approximately 84 % for a treatment time of 60 min. Also, a
notable improvement of the fatigue performance of 174 % was achieved after a treatment time of
40 min in comparison to the as-built reference samples.",,,,,,
"['Goel, Abhishek', 'Bourell, David']",2021-09-28T20:10:09Z,2021-09-28T20:10:09Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88171', 'http://dx.doi.org/10.26153/tsw/15112']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['room temperature infiltration', 'selective laser sintered preforms with metals', 'electrochemical deposition', 'electrochemical infiltration']",Electrochemical Infiltration of Laser Sintered Preforms with Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7eb14903-c1eb-4879-8409-05456042b4dd/download,University of Texas at Austin,"The proposed work deals with room temperature infiltration of selective laser sintered preforms
with metals. The approach adopted for carrying out room temperature infiltration was adaptation
and modification of electrochemical deposition techniques. Electroless deposition and
Electrolytic deposition processes were modified in order to carry out metal ion infiltration and
their deposition on the walls of the interconnected pores. The electrolytic infiltration process was
modified by inserting a conductive graphite cathode in the center in order to attract positive
nickel ions through the interconnected porous network and hence deposit them on the walls of
the pores. One of the major advantages of electrochemical infiltration is the lower processing
temperature. Low temperature reduces both energy consumption and associated carbon-footprint
and also minimizes undesirable structural changes. Both conductive and non-conductive
preforms can be electrochemically infiltrated and MMCs produced by this method have potential
for use in structural applications. This research was sponsored by the National Science
Foundation, Grant DMI-0522176.",,,,,,
"['Patel, Krish', 'McNamee, Amelia', 'Silwal, Bishal']",2021-11-18T19:04:43Z,2021-11-18T19:04:43Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90470', 'http://dx.doi.org/10.26153/tsw/17391']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['electroforming', 'microscale structures', 'copper', 'additive manufacturing']",Electroforming Process to Additively Manufactured Microscale Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b563007-8dd7-4785-b9fd-16bcee1d3f8b/download,University of Texas at Austin,"Electroforming is a metal forming process that forms parts through electrodeposition. The
overall study and production of the copper mandrel were conducted by examining the growth
and depth of the depositions at macroscopic levels. The study of the plating constant for a copper
plate in copper sulfate was performed via the production of copper mandrels. Each mandrel was
produced by performing multiple experiments and qualitatively and quantitatively examining the
resultant depositions and the initial and final states of the experiment. The results were measured
based on variations of current and voltage duration in the bath cycle, time duration, solution
concentration, and change in mass of both the anode and cathode. The variables such as plating
constant and direct current distribution are determined. It seems the rate at which the structure
can be fabricated depends on the type of electrolytes used and the parts that are deposited can be
scalable.",,,,,,
"['Kircher, R.S.', 'Christensen, A.M.', 'Wurth, K.W.']",2021-09-29T14:14:26Z,2021-09-29T14:14:26Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88178', 'http://dx.doi.org/10.26153/tsw/15119']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'orthopaedic implants', 'Co-Cr-Mo Alloy']",Electron Beam Melted (EBM) Co-Cr-Mo Alloy for Orthopaedic Implant Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7a308f3-1136-4256-a65b-ca162daa153d/download,University of Texas at Austin,"The Electron Beam Melting (EBM) manufacturing process is emerging as an additional method
for producing orthopaedic devices in several materials, including Co-Cr-Mo Alloy. This work
presents the chemical, microstructural and mechanical properties of several test specimens
produced by the EBM process before and after a post‐EBM Heat treatment. Comparisons are
made to the properties of Co-Cr-Mo materials used within the orthopaedic implant industry
processed by conventional methods such as investment casting and machining from wrought.
The results of the work are promising, and demonstrate that EBM produced Co-Cr-Mo material
has comparable, and in several cases superior microstructural and mechanical properties to those
found in the traditionally-processed materials used today.",,,,,,
"['Dave, V.R.', 'Matz, J.E.', 'Eagar, T.W.']",2018-10-04T19:45:04Z,2018-10-04T19:45:04Z,1995,Mechanical Engineering,doi:10.15781/T2542JT42,http://hdl.handle.net/2152/68707,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Solid free-form fabrication', '3D Printing', 'SLS']",Electron Beam Solid Freeform Fabrication of Metal Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3d313f19-0f47-4e0e-a710-9bd3a1c3233f/download,,"A novel method for near-net-shape fabrication of large, complex metal parts without the need
for specific tooling is described. Parts are built up in a layer-by-Iayer fashion by feeding raw
material in wire form into a melt pool which is maintained with an electron beam. Several different
alloys have been successfully deposited using a low-energy electron beam. A model has been
developed which permits determination ofthe melt depth and vaporization-limited power input as
functions of beam energy and travel velocity. Processing parameters obtained from experiments
with low-energy electron beams can be used to predict melting behavior under the influence of
higher energy beams. The process is being investigated as a possible means for manufacturing
compositionally-graded components.",,,,,,
"['Castillo, Sylvia', 'Muse, Dan', 'Medina, Frank', 'MacDonald, Eric', 'Wicker, Ryan']",2021-09-29T18:10:24Z,2021-09-29T18:10:24Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88205', 'http://dx.doi.org/10.26153/tsw/15146']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'stereolithography', 'direct-print', 'hybrid manufacturing', 'conformal electronics', 'accelerometer', 'three-dimensional electronics']",Electronics Integration in Conformal Substrates Fabricated with Additive Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ba9e9dd-93c2-42a0-b298-8f7f6279d048/download,University of Texas at Austin,"A three-dimensional (3D) accelerometer sensor system with microprocessor control was
fabricated using a previously developed integrated layered manufacturing system that combines
conductive ink dispensing with stereolithography (SL). The electronics are integrated into a
conformal substrate that is press-fit into a helmet for the purpose of detecting Traumatic Head
Injury (THI) when an excessive acceleration to the head is measured. Applications include
monitoring the health of soldiers or athletes. Traditional fabrication of electronics is
implemented with a 2 dimensional printed circuit board (PCB), which are not well suited for
rugged installations in curved locations such as the interior of a helmet. The advantage of
layered manufacturing for the integration of electronics is the ability to fabricate in a conformal
substrate - conforming to the curved, complex, and often flexible shapes dictated by the human
body.",,,,,,
"['Yang, L.', 'Wu, Yan', 'Lassell, Austin', 'Zhou, Bin']",2021-10-28T19:33:02Z,2021-10-28T19:33:02Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89677,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['surface treatment', 'electropolishing', 'electron beam melting', 'Ti6Al4V', 'fatigue']",Electropolishing of Ti6Al4V Parts Fabricated by Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c60caa38-d628-4f01-993b-61485f6257e2/download,University of Texas at Austin,"In this study Ti6Al4V samples fabricated via electron beam melting were subjected to
electropolishing under various polishing conditions using the re-designed in-house
electropolishing device. The surface finish of the processed samples were characterized,
and the tension-tension fatigue properties of the samples were evaluated via
experimentation. The results provided preliminary information about the effect of
electropolishing on surface crack initiation of the electron beam melted Ti6Al4V parts.",,,,,,
"['Melvin, Lawrence S. III', 'Beaman, J.J.']",2018-04-17T16:56:04Z,2018-04-17T16:56:04Z,1991,Mechanical Engineering,doi:10.15781/T2NV99T6C,http://hdl.handle.net/2152/64333,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'electrostatic powder', 'particle']",The Electrostatic Application of Powder for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a4db63f-035b-4be4-93ba-999f48755882/download,,,,,,,,
"['Benning, Matthew', 'Dalgarno, Kenny']",2021-10-19T15:40:40Z,2021-10-19T15:40:40Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89303,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['drop-on-demand', 'bioprinting', 'bioprinting ink', 'electrostatic stabilization', 'cationic encapsulation', 'osteosarcoma cells', 'osteosarcoma']",Electrostatic Stabilisation of Drop on Demand Bio‐Ink through the Cationic Encapsulation of Cells,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cb865fdc-14fe-446c-bf77-eeb626ebeee0/download,University of Texas at Austin,"The ability to formulate bioprinting inks in which suspensions of cells and other biological materials
can be maintained, without affecting biological response, is crucial in producing robust printing
strategies for tissue fabrication. A piezoelectrically actuated drop‐on‐demand printing system has
been used to deposit electrostatically stabilised cells from a human osteosarcoma cell line (U2OS).
Experiments were intended to investigate the effectiveness of a polyelectrolyte cell encapsulant to
maintain cell dispersion within a bio ink. Cells were coated with a number of thicknesses of a
Cationic Poly‐l‐lysine (PLL) encapsulant and their ability to release studied over 7 days, with the
thinner coatings proving to be more favourable. Printing of both coated and uncoated cells indicated
the dispersion and printability of coated cells was significantly better than that of uncoated cells.
Preliminary results suggest that electrostatic stabilisation of bio inks could provide a solution to cell
aggregation, increasing viable printing time and decreasing poor yields due to orifice obstruction.",,,,,,
"['zur Jacobsmühlen, J.', 'Kleszczynski, S.', 'Witt, G.', 'Merhof, D.']",2021-10-20T20:48:45Z,2021-10-20T20:48:45Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89358,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser beam melting', 'elevated region area', 'process stability']",Elevated Region Area Measurement for Quantitative Analysis of Laser Beam Melting Process Stability,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0937b043-1d46-425f-8346-1850ae393978/download,University of Texas at Austin,"Laser beam melting (LBM) processes enable layer-based production of geometrically
complex metallic parts with very good mechanical properties for Rapid Manufacturing. Collisions between powder coating mechanism and elevated part regions pose a major risk to
process stability, which is crucial for industrial application. Minimizing elevated region area
usually involves parameter tuning in a trial-and-error approach, as the process outcome is
the only measure of stability. One published approach to quantifying elevated region area
utilizes an imaging system, which acquires layer images of the powder bed after powder
deposition and detects elevated regions using image analysis. We extend the image-based
analysis to each part region, create quantitative visualizations of elevated region area for
quick assessment/comparison and compute a figure of merit. In experimental build jobs
with overhanging structures and different support junction parameters we gain insight into
problematic part regions, which can be used as feedback in job design. The presented method
helps to improve LBM process stability, which is strongly linked to process efficiency.",,,,,,
"['Hecht, G.R.', 'Isanaka, S.P.', 'Newkirk, J.W.']",2021-11-17T23:40:29Z,2021-11-17T23:40:29Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90356', 'http://dx.doi.org/10.26153/tsw/17277']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['304L', 'stainless steel', 'high temperature', 'tensile strength', 'tensile elongation', 'microstructure', 'selective laser melting']",Elevated Temperature Mechanical and Microstructural Characterization of SLM SS304L,Conference paper,https://repositories.lib.utexas.edu//bitstreams/89fb67ef-c256-441a-a335-3c92523ba536/download,University of Texas at Austin,"SLM built SS304L was annealed and water quenched to minimize residual stress and
avoid carbide precipitation. Mini-tensile characterization of strength and elongation at
temperature conditions up to 800˚
C, along with observations of the associated microstructural
transformations were utilized to understand the changes produced in SLM SS304L. As-built and
annealed specimens were found to exhibit decreasing strength and elongation with increasing
temperature as expected. Carbide precipitates appeared after short times at high temperatures
within both as-built and annealed specimens for all cases, but no brittle intermetallic phase
development was observed for any of the temperatures investigated. While the lack of Sigma,
Chi or Laves phases were anticipated, the premature formation of carbides is unexpected
behavior for this composition of SS 304L. It is an indication of higher sensitivity of SLM made
material. An additional change in the etch response was also observed between as-built and
annealed specimens. It is theorized that annealing caused all ferritic and other residual phases
present in as-built SLM SS 304L to fully transform into austenite. The cellular structure
observed in the as-built specimen was also dissolved due to annealing and water quenching
possibly leading to the strength loss observed.",,,,,,
"['Amine, Tarak', 'Newkirk, Joseph']",2021-10-27T21:21:55Z,2021-10-27T21:21:55Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89618,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'elevated temperatures', 'microstructural stability', '304L', 'stainless steel']",Elevated Temperature Microstructure Stability of SLM 304L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b513bf9f-b48f-465f-b690-246d2330b3bd/download,University of Texas at Austin,"At elevated temperatures changes in metallurgical structure can be expected for almost any
steel or alloy. In stainless steels, the changes can be grain growth, carbide precipitation, ferrite
decomposition, or embrittlement. These phenomena can significantly affect the properties of the
stainless steel and would potentially change the functionality of the component. Therefore, the
impact of elevated temperatures on the microstructure of SLM 304L stainless steel was studied.
The work reported here investigates the influence of different aging times at 300C on
microstructure and mechanical properties of stainless steels (304L) fabricated with the Selective
Laser Melting (SLM) process. Microstructure and mechanical properties were dramatically
effected at temperatures much lower than expected when compared to samples of wrought stainless
steel. The stainless steel fabricated using the SLM process was more kinetically active than
expected based on previous studies of 304L. Results of this study will be presented along with
possible reasons for the higher activity.",,,,,,
"['Snider, Elias B.', 'Saha, Rony Kumer', 'Dominguez, Cesar', 'Huang, Jie', 'Bristow, Douglas A.']",2024-03-26T20:45:28Z,2024-03-26T20:45:28Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124404', 'https://doi.org/10.26153/tsw/51012']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['direct energy deposition', 'fiber optic sensors', 'metal', 'additive manufacturing']",Embedding Fiber Optic Sensors in Metal Components via Direct Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d79748b-5005-46f2-bed0-209920e3c0b0/download,University of Texas at Austin,"Fiber optics are useful as strain and temperature sensors in a variety of applications
involving high-value parts. Embedding fiber optic sensors into end-use parts can allow for realtime strain and temperature monitoring of these parts in extreme conditions. Direct energy
deposition processes have distinct advantages for producing parts in high-value embedded sensing
applications, however, ensuring survival of the optical fiber during embedment is challenging. A
method of fiber embedment using high-temperature ceramic adhesives is presented as a flexible
method of embedding fiber optic sensors into end-use parts such as to preserve fiber transmission
and sensor integrity. Example specimens are presented, and functionality of sensing capabilities is
demonstrated.",,,,,,
"['Stoll, Philipp', 'Mathew, Jinesh', 'Spierings, Adriaan', 'Bauer, Thomas', 'Maier, Robert R.J.', 'Wegener, Konrad']",2021-10-28T22:16:01Z,2021-10-28T22:16:01Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89716,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fibre optical sensors', 'embedding', 'production environment', 'commercial SLM system', 'selective laser melting', 'SLM']",Embedding Fibre Optical Sensors into SLM Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83966afe-d07a-4b71-9b32-f872db6503b3/download,University of Texas at Austin,"Selective Laser Melting (SLM) facilitates the integration of additional functionalities such as
sensors into metallic parts. Such sensors can for example be embedded in sections of the parts
non accessible after manufacturing. Additionally they can be positioned close to the region of
interest. Depending on the type of sensor it is even possible to monitor the structural health of
the part itself. This paper discusses the integration of fibre optical sensors into SLM
manufactured coupons in a commercial, industry scale, SLM machine. Such systems have
merely limited accessibility for fibre handling. The embedment procedure as well as the
corresponding bonding quality is explained in detail. Measurement results of the embedded
sensor and limitations for the embedding procedure related to the use of commercial SLM
systems are presented. Additionally the need for further research is pointed out.",,,,,,
"['Li, Xiaochun', 'Prinz, Fritz B.']",2019-09-23T16:16:29Z,2019-09-23T16:16:29Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75954', 'http://dx.doi.org/10.26153/tsw/3053']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Optic,Embedding of Fiber Optic Sensors in Layered Manufacturing 314,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac0bc44f-eb50-4cc3-aeed-7f170c7b036d/download,,Layered manufacturing enables integrating sensors during production of tooling or structural components. Sensors may be placed close to the points of interest prior to enclosure. Structures with embedded sensors are capable of monitoring parameters at critical locations not accessible to ordinary sensors. This work presents a methodology for embedding fiber optic sensors in metallic structures via Shape Deposition Manufacturing. Some of the main manufacturing issues are discussed. Embedded fiber optic sensors have been employed to measure temperature and strain. Proof-of-concept experiments on a non-contact fiber optic sensing system have been performed. By implementing the remote sensing system it is possible to measure temperature and strain of rotating components exposed to potentially hostile environments such as blades in gas turbine engines.,"The authors are grateful to acknowledge the financial support for this work from Office
of Naval Research under the contract of N00014-96-1-0354-P00003.",,,,,
"['Zawaski, Callie', 'Margaretta, Evan', 'Stevenson, Andre', 'Pekkanen, Allison', 'Whittington, Abby', 'Long, Timothy', 'Williams, Christopher B.']",2021-11-04T18:55:45Z,2021-11-04T18:55:45Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90004', 'http://dx.doi.org/10.26153/16925']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['material extrusion', 'embedding', 'dissolvable materials', 'drug delivery']",Embedding of Liquids into Water Soluble Materials via Additive Manufacturing for Timed Release,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f32b8904-8126-4ecd-b71c-de14c267d243/download,University of Texas at Austin,"One fundamental goal of personalized medicine is to provide tailored control of the dissolution
rate for an oral dosage pill. Additive manufacturing of oral dose medicine allows for customized dissolution by tailoring both geometric and printed material properties. Direct processing of medicine
via filament material extrusion is challenging because many active agents become inactive at the
elevated temperatures found in the melt-based process. In this work, this limitation is circumvented
by incorporating the active agents via in-situ embedding into a priori designed voids. This concept of embedding active ingredients into printed parts is demonstrated by the in-situ deposition
of liquid ingredients into thin-walled, water soluble, printed structures. The authors demonstrate
the ability to tune dissolution time by varying the thickness of the printed parts walls using this
technique.",,,,,,
"Wasserfall, Florens",2021-10-19T18:21:52Z,2021-10-19T18:21:52Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89317,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'fused deposition modeling', 'electronic circuits', 'SMD-components']",Embedding of SMD Populated Circuits into FDM Printed Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91536d76-9c91-4687-b2a6-02b47c0d7e3a/download,University of Texas at Austin,"This paper introduces the concept of a highly integrated 3D-printing device which is capable of
printing plastic parts with integrated, fully assembled electronic circuits in a single process. It is
based on a standard FDM 3D-printer that has been augmented by a screw-driven conductive paste
extruder for electronic circuit printing, a vacuum nozzle to pick and place SMD-components and
a vision system to find and precisely align the components before placing. To control the printer,
an existing host software system has been extended to synchronize the communication with the
printer for interactive operations and to generate the required movements from camera data by
means of image processing.
A number of objects, containing circuits on both the surface and inside of the object, has been
successfully printed already. Quality and durability of the generated parts have been evaluated by
analyzing the curing characteristics of the conductive ink during the process and the adhesion of
the components which are placed directly on the wet ink. The design concept aims for a practical,
affordable approach that can be widely used by developers to lower the entrance barrier to the field
of 3D-printed electronics. Hence, the hardware is kept as simple as possible, avoiding complex
and expensive components as laser or CNC-milling devices, focusing on algorithmic improvements in the preprocessing and control software. All developed hard- and software-components
are available under open source licenses and compatible to common existing projects.",,,,,,
"['Turk, T.', 'Dougan, M.', 'Hendrix, L.', 'Reed, A.', 'Dominguez, C.E.', 'Suttonn, A.T.', 'Park, J.', 'Leu, M.C.']",2024-03-25T23:49:25Z,2024-03-25T23:49:25Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124344', 'https://doi.org/10.26153/tsw/50952']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['lasere foil printing', 'temperature sensor', 'additive manufacturing']",EMBEDDING TEMPERATURE SENSORS WITH THE USE OF LASER-FOILPRINTING ADDITIVE MANUFACTURING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b406f1ab-b80e-45c2-810b-ca47062a8b75/download,University of Texas at Austin,"Laser foil printing (LFP) is a metal additive manufacturing (AM) process using laser-based
melting of metal foil technique. Using metal foils in AM has advantages over laser powder-feed
processes, allowing for efficient heat transfer and resolving the drawbacks of powder-based AM
such as potential powder inhalation health hazards, balling, spattering, and high powder costs. In
this study, we demonstrate the advantage of LFP for embedding sensors into structures using 304L
stainless-steel foil as the feed material and two different types of temperature sensors. The first
type is a resistance temperature detector (RTD) platinum sensor (Pt 100), and the second type is a
k-type thermocouple probe. A detailed study of the sensor embedment through LFP revealed that
the spot-welding scanning strategy significantly improves the product quality than conventional
line-welding scanning strategy. As a result of this study, the feasibility of fabricating functional
parts with embedded sensors using the LFP process is demonstrated.",,,,,,
"['Sih, Samuel Sumin', 'Barlow, Joel W.']",2018-11-08T15:25:31Z,2018-11-08T15:25:31Z,1995,Mechanical Engineering,doi:10.15781/T2V40KJ7S,http://hdl.handle.net/2152/69888,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['thermal models', 'SLS', 'emissivity']",Emissivity of Powder Beds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cf95915c-530e-4ee2-8d39-30bfeb282377/download,,"A simple model for estimating the emissivity ofthe surface of a powder bed from
knowledge only ofthe bed porosity and solid emissivity is presented. Estimates by this
model are compared with experimental measurements for powder beds of alumina, silicon
carbide, and iron. Agreement within the uncertainty ofthe measurements, ± 10%, is
obtained",,,,,,
"['Boddu, Mallikharjuna', 'Musti, Srinivas', 'Landers, Robert G.', 'Agarwai, Sanjeev', 'Liou, Frank W.']",2019-10-18T16:14:24Z,2019-10-18T16:14:24Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76250', 'http://dx.doi.org/10.26153/tsw/3339']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Deposition,Empirical Modeling and Vision Based Control for Laser Aided Metal Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93f36d78-707d-439a-ab35-59cdd97ba2aa/download,,"This paper gives a brief description of the laser aided manufacturing process. Empirical
models describing the process dynamics of the laser aided metal deposition process is developed
based on some of the models found in the literature. These models provide the basis for process
planning and real time control. An embedded vision system, a two color temperature sensor, and
a laser displacement sensor are incorporated for real time monitoring and control of the
deposition process. The temperature profile of the surface and geometric characteristics of the
melt pool are studied to ensure consistent operation of the process.",,,,,,
"['Cho, Uichung', 'Wood, Kristin']",2018-12-06T22:07:17Z,2018-12-06T22:07:17Z,1997,Mechanical Engineering,doi:10.15781/T2JD4Q88T,http://hdl.handle.net/2152/71434,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'SFF']",Empirical Similitude Method for the Functional Test with Rapid Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ecd30a7a-50cc-4a76-ba42-ce59749c9cfc/download,,"Rapid prototyping has the potential to improve the performance of the design process
both in cycle time and resources. Such improvements may be realized through the timely
visual, ergonomic, and functional information provided by solid freeform fabrication (SFF)
parts. Of these information classes, functional information is perhaps the least realized with
current technology. A number of technical issues have limited functional testing of SFF
parts, including sensor fusion, range of prototyping materials, part size etc. Our focus here
concerns the material issues of functional testing, especially the potential differences in
prototyping material choices to actual production materials. For example, to derive accurate
functional information of non-polymeric products from polymeric rapid prototypes, an
improved similitude method that can overcome the distortion of material characteristics is
necessary. In this paper, a new similitude method that utilizes specimen test data is
introduced. This method develops a mathematical transformation between prototype and
product behavior through specimen testing. This transformation replaces the role ofthe scale
factor of the traditional similitude method, and provides a basis for relating prototypes to
proposed production parts, even under dependent loading and material conditions.
Computational and experimental results of a structural design provide verification ofthe new
method.",,,,,,
"['Mehta, Priyesh', 'Berdanier, Catherine G.P.', 'Malviya, Manoj', 'Miller, Colin', 'Manogharan, Guha']",2021-11-16T15:49:07Z,2021-11-16T15:49:07Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90320', 'http://dx.doi.org/10.26153/tsw/17241']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['design for AM', 'topology optimization', 'design framework', 'eye-tracking', 'manufacturability and additive manufacturing education']",An Empirical Study Linking Additive Manufacturing Design Process to Success in Manufacturability,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b93b0a5-7270-4ac1-ba9a-d29baf612182/download,University of Texas at Austin,"This paper characterizes engineering designers’ abilities to re-design a component for
additive manufacturing, employing screen capture methods. Additive Manufacturing has garnered
significant interest from a wide range of industries, academia and government stakeholders due to
its potential to reform and disrupt traditional manufacturing processes. The technology offers
unprecedented design freedom and customization along with its ability to process novel and high
strength alloys in promising lead times. To harness the maximum potential of this technology,
designers are often tasked with creating new products or re-design existing portfolios of
traditionally manufactured parts to achieve lightweight designs with better performance. To date,
few studies explore the correspondence between design behaviors and manufacturability of final
product within an Additive Manufacturing context. This paper presents empirical data from the
design processes of six graduate student engineering designers as they re-design a traditionally
designed part for additive manufacturing. Behaviors through the design task are compared between
the study participants with a quantitative measure of the manufacturability and quality of each
design. Results indicate opportunities for further research and best practices in design for Additive
manufacturing and engineering education practitioners across multiple disciplines.",,,,,,
"['Bartsch, K.', 'Emmelmann, C.']",2021-12-01T22:07:06Z,2021-12-01T22:07:06Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90632', 'http://dx.doi.org/10.26153/tsw/17551']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['support structures', 'optimization', 'laser powder bed fusion', 'PBF-LB/M']",Enabling Cost-based Support Structure Optimization in Laser Powder Bed Fusion of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97680dc1-59fd-406c-a1ff-b084729988a1/download,University of Texas at Austin,"Support structures are essential to laser powder bed fusion (PBF-LB/M). They sustain overhangs,
prevent distortion, and dissipate process-induced heat. Their removal after manufacturing is
required, though, increasing the overall costs. Therefore, optimization is important to increase
the economic efficiency of PBF-LB/M. To enable optimization focused on the support
structures’ costs, a cost model is developed. The whole production process, including the design,
manufacturing, and post-processing of a part is considered by deriving formulas for the
individual costs. The cost model is applied to a benchmark procedure previously developed.
Additionally, a case study investigating different support layout strategies is conducted.",,,,,,
"Clemon, Lee M.",2021-10-28T22:42:11Z,2021-10-28T22:42:11Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89721,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['energy consumption', 'global warming emissions', 'fused deposition modeling', 'job-shop']",Energy and Emission Estimation Uncertainty in Fused Deposition Modeling for a Job-Shop,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9e964f38-fcd5-413c-bdb0-0ec6e888458b/download,University of Texas at Austin,"Solid freeform fabrication has the potential to affect both financial and environmental
concerns for manufacturing enterprises. However, when planning for installation of a new machine
tool, accurate energy usage estimation relies heavily on the data and model selections of the
estimator. This project used a variety data sources and model decision options to examine the
spread of energy consumption and global warming potential estimates for a fused deposition
modeling machine. In addition to primary and secondary data sources, the use of similar machines
was explored as proxy estimates for the target machine. A Monte Carlo simulation was constructed
to vary the model selections, machine utilization, and data sources. The results indicated data
sources and model decisions had large effects on the output and that most model estimates were
low.",,,,,,
"['Kellens, K.', 'Yasa, E.', 'Renaldi', 'Dewulf, W.', 'Kruth, J.P.', 'Duflou, J.R.']",2021-10-04T20:10:24Z,2021-10-04T20:10:24Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88333', 'http://dx.doi.org/10.26153/tsw/15272']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering (SLS)', 'Selective Laser Melting (SLM)', 'life cycle assessment', 'sustainable manufacturing', 'energy and resource efficiency', 'CO2PE!-Initiative']",Energy and Resource Efficiency of SLS/SLM Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b180a7c3-5327-4a3a-8e05-bd14c1e80e80/download,University of Texas at Austin,"Manufacturing processes, as used for discrete part manufacturing, are responsible for a
substantial part of the environmental impact of products, but are still poorly documented in
terms of their environmental footprint. The lack of thorough analysis of manufacturing
processes has as consequence that optimization opportunities are often not recognized and
that improved machine tool design in terms of ecological footprint has only been targeted for
a few common processes.
Additive manufacturing processes such as Selective Laser Sintering (SLS) and
Selective Laser Melting (SLM) allow near-net shape manufacturing of complex work pieces.
Consequently, they inherently offer opportunities for minimum-waste and sustainable
manufacturing. Nevertheless, powder production, energy consumption as well as powder
losses are important and not always optimized environmental impact drivers of SLS and
SLM. This paper presents the results of a data collection effort, allowing to assess the overall
environmental impact of these processes using the methodology of the CO2PE! (Cooperative
Effort on Process Emissions in Manufacturing) initiative.
Based on the collected LCI data, a subsequent impact assessment analysis allows
identifying the most important contributors to the environmental impact of SLS/SLM. Next
to the electricity consumption, the consumption of inert gasses proves to be an important
cause of environmental impact. Finally, the paper sketches the improvement potential for
SLS/SLM on machine tool as well as system level.",,,,,,
"['Patil, Nachiket', 'Pal, Deepankar', 'Stucker, Brent E.']",2021-10-11T22:03:42Z,2021-10-11T22:03:42Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88659', 'http://dx.doi.org/10.26153/tsw/15593']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['finite element based constitutive model', 'energy dissipation', 'Ultrasonic Consolidation', 'dislocation density based crystal plasticity finite element model', 'weld defects']",An Energy Dissipative Constitutive Model for Multi-Surface Interfaces at Weld Defect Sites in Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/540cac9b-3b9f-4b68-8f8c-c1b399b6d2bd/download,University of Texas at Austin,"A new finite element based constitutive model has been developed for quantification of energy
dissipation due to friction and plastic deformation at the mating interface of two surfaces during
the Ultrasonic Consolidation process. This work will include bridging the mesoscopic response of
a dislocation density based crystal plasticity finite element framework at inter and intra-granular
scales and a point at the macroscopic scale. This response will be used to develop an energy
dissipative constitutive model for multi-surface interfaces at the macroscopic scale. The
constitutive model will be used for quantification of energy consumed at lack of fusion and trapped
oxide defects present in the build and the amount of energy input required to compensate for it.
This numerical procedure will help in real time optimization of process parameters and closed loop
control.",,,,,,
"['Verma, Anoop', 'Rai, Rahul']",2021-10-07T17:46:08Z,2021-10-07T17:46:08Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88493', 'http://dx.doi.org/10.26153/tsw/15427']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'optimization', 'energy efficiency', 'material wastage', 'energy consumption', 'medical', 'aerospace']",Energy Efficient Modeling and Optimization of Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/201111f6-181f-4f4d-97cf-3341e664359b/download,University of Texas at Austin,"Additive manufacturing (AM) is a leading technology in various industries including medical and aerospace
for prototype and functional part fabrication. Despite being environmentally conscious, avenues pertaining to
further reducing the impact of AM on the environment exist. Material wastage and energy consumption are
two major concerns of the process that requires immediate attention. In this research, a multi-step optimization
enabling additive manufacturing process towards energy efficiency is developed. Process objectives such as
material waste and energy consumption are minimized both in part and layer domain. Numerous examples are
presented to demonstrate the applicability of the developed approach. The models formulated here for selective
laser sintering (SLS) process can be easily extended to other additive manufacturing technologies.",,,,,,
"['Sharma, Maharshi A.', 'Patterson, Albert E.']",2024-03-26T17:03:01Z,2024-03-26T17:03:01Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124375', 'https://doi.org/10.26153/tsw/50983']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['FFF process', 'extrusion-based additive manufacturing', 'bond-graph model', 'dynamic modeling']",Energy Flow (Bond Graph) Dynamic Modeling of Cartesian-Frame FFF 3-D Printer Gantry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e87c345f-1cc7-4575-a706-7580e330f929/download,University of Texas at Austin,"Energy flow (bond graph) modelling gives important information about the flow of energy to each component
of a dynamic system and is especially useful for complex non-linear mechanical systems. This work presents a
systematic development of a bond graph model of fused filament fabrication (FFF) 3D printer gantry. The model
incorporates structural and belt stiffness, damping and input torque. The model was checked for correctness and
causality using the 20-SIM software. The model was further validated using MATLAB-Simulink using parameters
obtained for an example printer characterized in a lab environment. The bond graph model gives a unique view into
modelling of the extruder carriage dynamics in FFF and can be applied to specific problems. It will also give interesting
information on the controllability and system integration of the printer hardware.",,,,,,
"['Baumers, M.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Hague, R.']",2021-10-04T20:18:12Z,2021-10-04T20:18:12Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88336', 'http://dx.doi.org/10.26153/tsw/15275']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'electricity consumption', 'AM technology', 'AM technology variants', 'capacity utilization']",Energy Inputs to Additive Manufacturing: Does Capacity Utilization Matter?,Conference paper,https://repositories.lib.utexas.edu//bitstreams/39d4cf41-e8db-4729-af80-b4b01d64a9e0/download,University of Texas at Austin,"The available additive manufacturing (AM) platforms differ in terms of their
operating principle, but also with respect to energy input usage. This study presents an
overview of electricity consumption across several major AM technology variants, reporting
specific energy consumption during the production of dedicated test parts (ranging from 61 to
4849 MJ per kg deposited). Applying a consistent methodology, energy consumption during
single part builds is compared to the energy requirements of full build experiments with
multiple parts (up to 240 units). It is shown empirically that the effect of capacity utilization
on energy efficiency varies strongly across different platforms.",,,,,,
"['Papadatos, Alexandre L', 'Stanley Jr, Kenneth', 'Ahzi, Said', 'W. Paul, Frank']",2019-02-19T16:45:40Z,2019-02-19T16:45:40Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73428', 'http://dx.doi.org/10.26153/tsw/580']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['commercial Rapid Prototyping', 'GSI scanners']",Enhanced controlling of the SLS Process during a build,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e6debe7a-38e1-48cd-95d1-1591175c28fd/download,,"Current commercial Rapid Prototyping (RP) systems like Stereolithography (3D
Systems Corporation) and Selective Laser Sintering (DTM Corporation) use
galvanometers from General Scanning Inc. (GSI) for the positioning of the laser beam.
The GSI scanners are delivered as a ''black box"". Operating Consoles which are usually
Personal Computers (PC) have very few feedback from the performance of the GSI
scanners. Therefore, the PC spends 9000 or more of its time waiting for the GSI scanners
to be over with the building of the current layer before sending the information
regarding the next layer. Also, very little process control can be performed during the
scanning of a layer using the GSI scanners. This kind of setup prevents any dynamic
controlling of the process that could prevent building errors like burning, warping etc.
At Clemson University, our team has developed both hardware and software
components that allows a dynamic control of the building process. New features like
scanning one vector with laser power as a function of position and/or time are now
possible. Both hardware and software issues will be presented.",,,,,,
"['Pal, D.', 'Patil, N.', 'Teng, C.', 'Zeng, K.', 'Xu, S.', 'Sublette, T.', 'Stucker, B.']",2021-10-18T22:06:03Z,2021-10-18T22:06:03Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89267,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'spatiotemporal multiscaling', 'thermomechanical travelling wave', 'Finite Element simulations']",Enhancing Simulations of Additive Manufacturing Processes Using Spatiotemporal Multiscaling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/afc09039-a75a-410f-a519-fa8cac1383fa/download,University of Texas at Austin,"The three integral components which are common to all additive manufacturing machines
are energy source(s), material(s) and geometrical representation(s). The interaction of these
components lead to coupled multiscale thermomechanical phenomena. The overall response due
to dynamic localized boundary conditions leads to travelling thermomechanical waves with their
origin at the point/line or plane of energy input and finite boundaries located at the extremities of
the build chamber of the machine. At these finite boundaries, three phenomena occur, namely
reflection, absorption and transmission of the thermomechanical travelling wave. Based on the
boundary conditions, any combinations of the mentioned finite boundary phenomena are activated
leading to a finite mismatch between the boundary condition and ordinate of the travelling wave
at the finite boundary abscissae. This finite mismatch leads to another thermomechanical travelling
wave which travels from the finite boundary towards the location of energy input and the process
of generation of thermomechanical waves continues till a standing steady state thermomechanical
wave converges at each snapshot in time. An important aspect of these forward and backward
moving travelling waves is their spatiotemporal thermomechanical curvature as a function of space
which leads to spatiotemporal multiscale modeling of these processes. Spatial and temporal
examples with multi-order and multi-rank updates of thermal eigensolutions with inhomogeneity
in the –z direction and thermal stiffness as a function of time stepping were thus studied to
understand their effects on efficient Finite Element simulations of metal additive manufacturing
processes.",,,,,,
"['Jacksch, A.', 'Cholewa, C.', 'Drummer, D.']",2024-03-25T22:10:34Z,2024-03-25T22:10:34Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124314', 'https://doi.org/10.26153/tsw/50922']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['polyamide 6', 'PA6', 'thermal stability', 'powder bed fusion', 'PBF', 'additive manufacturing']",Enhancing the Thermal Stability of Polyamide 6 in Powder Bed Fusion via Primary and Secondary Antioxidant Incorporation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d6726d91-8555-4c1c-9006-de3e848bad2d/download,University of Texas at Austin,"Polyamide 6 (PA6) is a thermoplastic material widely used in manufacturing for its excellent mechanical
properties, such as high strength, stiffness, and toughness. However, its suitability for powder bed fusion (PBF)
is limited due to its susceptibility to thermo-oxidative aging, resulting in material degradation and mechanical
property deterioration over time. To address this issue, the efficacy of antioxidants in increasing the aging
resistance of PA6 in PBF was investigated. Process-adapted analysis was employed using a coupled rheometer
FTIR instrument to elucidate physical and chemical changes in the material. In addition, the viscosity number of
the virgin and processed powder, the yellow index, and the part performance were evaluated. Results revealed
that the addition of primary and secondary antioxidants significantly enhanced the aging resistance of PA6 in
PBF, thereby increasing its potential as a suitable material for additive manufacturing applications.",,,,,,
"['Pegues, Jonathan', 'Roach, Michael', 'Williamson, R. Scott', 'Shamsaei, Nima']",2021-11-18T00:01:23Z,2021-11-18T00:01:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90363', 'http://dx.doi.org/10.26153/tsw/17284']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['stress corrosion cracking', 'environmentally assisted cracking', 'austenitic stainless steel', 'tensile properties']",Environmental Effects on the Stress Corrosion Cracking Behavior of an Additively Manufactured Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1cd0a9b-b22c-4440-9c0c-5d12cba7a0d1/download,University of Texas at Austin,"Additive manufacturing (AM) is becoming a more viable manufacturing process in the
biomedical, aerospace, nuclear, and defense sectors as a means to fabricate near net shaped parts
on demand. Austenitic stainless steels are gaining attention for AM of products for these
applications due to their ease of fabrication, excellent corrosion resistance, and superior toughness.
The performance of these alloys fabricated by AM techniques such as laser beam powder bed
fusion has not been yet fully established. This research compares the microstructural
characteristics and tensile stress corrosion cracking (SCC) of 316L stainless steel at room
temperature and physiological temperature in distilled H2O, salt water, Ringers, and spiked pH
Ringers conditions.",,,,,,
"['Niu, Michelle', 'Nauka, Krztsztof']",2024-03-27T03:11:44Z,2024-03-27T03:11:44Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124458', 'https://doi.org/10.26153/tsw/51066']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['metal powder surface energy modification', 'additive manufacturing', 'high energy light irradiation']",Equalization of Metal Powder for Binder Jet Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c7a7d8b3-f874-4cd5-a3c4-aff534f51f0b/download,University of Texas at Austin,"Metal powders used in additive manufacturing often face the issue of variable powder surface
characteristics, causing inconsistent part quality. As such, a ”homogenization” treatment for metal
powder surfaces may be advantageous for relevant fabrication processes. By using high-powered
xenon flash lamp to rapidly heat powder samples, the surface energy of the powder particles was
brought to the same value regardless of the powder source and past usage. Pulse-heating the
powder caused the atomic structure of particle surfaces to undergo rearrangement and removed
adsorbed moieties. Effects of this treatment on metal powders have been investigated and evaluated
by measuring the time before water droplets are absorbed on treated and untreated thin layers.",,,,,,
"['Miyanaji, Hadi', 'Yang, Li']",2021-11-01T20:44:47Z,2021-11-01T20:44:47Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89742,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', '3D printing', 'equilibrium saturation', 'spreading', 'penetration']",Equilibrium Saturation in Binder Jetting Additive Manufacturing Processes: Theoretical Model vs  Experimental Observations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/754e405e-c88f-4d88-8d1b-502a5f5ead0f/download,University of Texas at Austin,"In Binder Jetting 3D Printing process, a feature is fabricated by depositing binder in the
selective regions layer by layer until the geometry is completed. One of the main factors which
influences the accuracy and strength of the green parts in this process is the spreading (i.e. lateral
migration) and penetration (vertical migration) of the binder in powder bed, which is in turn
determined by the capillary equilibrium between the saturated regions and the unsaturated powder.
In the present study, a previously developed model for binder migration was applied to 420
stainless steel in order to evaluate the equilibrium saturation levels. Characterizations such as
contact angle, specific surface area, succession pressure and capillary pressure were carried out in
order to determine the theoretical equilibrium saturation amount. Furthermore, 10 single lines with
dimensions of 46μm in diameter and 3mm in length were printed out and analyzed for empirical
saturation level. The results of the theoretical model and experimental work were compared and
discussed in details to validate its applicability in binder jetting process development.",,,,,,
"['Kleszczynski, S.', 'zur Jacobsmühlen, J.', 'Sehrt, J.T.', 'Witt, G.']",2021-10-07T14:46:56Z,2021-10-07T14:46:56Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88467', 'http://dx.doi.org/10.26153/tsw/15404']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Laser Beam Melting', 'error detection', 'high-resolution imaging', 'aerospace', 'medicine']",Error Detection in Laser Beam Melting Systems by High Resolution Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b800d101-afd4-43b4-8362-8a6d96e64e83/download,University of Texas at Austin,"Laser Beam Melting as a member of Additive Manufacturing processes allows the
fabrication of three-dimensional metallic parts with almost unlimited geometrical complexity and
very good mechanical properties. However, its potential in areas of application such as aerospace
or medicine has not yet been exploited due to the lack of process stability and quality
management. For that reason samples with pre-defined process irregularities are built and the
resulting errors are detected using high-resolution imaging. This paper presents an overview of
typical process errors and proposes a catalog of measures to reduce process breakdowns. Based
on this systematical summary a future contribution to quality assurance and process
documentation is aspired.",,,,,,
"['Masoomi, Mohammad', 'Paudel, Basil', 'Shamsaei, Nima', 'Thompson, Scott M.']",2021-11-11T16:51:55Z,2021-11-11T16:51:55Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90247', 'http://dx.doi.org/10.26153/tsw/17168']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser-powder bed fusion', 'numerical simulation', 'numerical modeling', 'temperature gradiennt', 'part performance']",Establishing Property-Performance Relationships through Efficient Thermal Simulation of the Laser-Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dfa85c35-97e4-4a71-af40-2ebeb89e85ef/download,University of Texas at Austin,"In order to learn how to modify additive manufacturing designs and processes to ensure lab-scale
specimens and final components have similar properties, it is important that process-property
relationships be established through thermal simulations. In this study, two unique numerical
methods for efficiently predicting the thermal history of additively manufactured parts via
simulation are presented and validated. These numerical methods make use of an idealized,
constant/uniform heat flux which is applied at each new layer and ‘bulk-layers’ which consist of
several layers and allow the use of coarser meshes and longer time steps. To demonstrate and test
the numerical methods, simulations are ran for the laser-powder bed fusion (L-PBF) of stainless
steel (SS) 17-4 PH parts with different volumes. Simulation results indicate how to modify L-PBF
process parameters, specifically time intervals, to better ensure a similar thermal history,
temperature, temperature gradient and cooling rate, of different sized/shaped parts.",,,,,,
"['Johnson, A.', 'Bingham, G.A.', 'Majewski, C.E.']",2021-10-05T19:10:02Z,2021-10-05T19:10:02Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88412', 'http://dx.doi.org/10.26153/tsw/15351']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufactured Body Armour', 'Laser Sintering', 'body armour', 'Home Office Scientific Development Branch', 'National Institute of Justice']",Establishing the Performance Requirements for Stab Resistant Additive Manufactured Body Armour (AMBA),Conference paper,https://repositories.lib.utexas.edu//bitstreams/c29d7ade-4d2f-4142-a615-9663ddc31896/download,University of Texas at Austin,"Body armour is worn to lessen the likelihood of sustaining a life threatening injury.
Such protective solutions are used every day by law enforcement officers around the world,
with strict guidelines governing their design and testing. These activities are monitored by
government departments such as the Home Office Scientific Development Branch (HOSDB)
within the United Kingdom (UK), and the National Institute of Justice (NIJ) within the
United States.
Despite providing protection against significant levels of impact energy, a number of
historical issues continue to be present with modern fibre-based soft body armour – which
once addressed may demonstrate an enhancement wearer operational performance.
This paper therefore presents research highlighting such issues, and demonstrates how
Additive Manufacturing (AM) technologies, particularly Laser Sintering (LS), could
potentially be used to address such operational concerns whilst providing protection against a
real-world threat.
Results documented within this paper demonstrate that 5.6 mm thick planar samples,
Laser Sintered from a 50/50 mix of virgin and recycled PA 2200 successfully achieved
penetration resistance to the UK HOSDB KR1 impact energy of 24 joules. These results
therefore influenced the design, manufacture, and testing of a series of AM textile samples
featuring an imbricated layout, which also demonstrated successful knife penetration
resistance to the HOSDB KR1 level – thus developing stab resistant Additive Manufactured
Body Armour (AMBA).",,,,,,
"['Park, Sang-in', 'Watanabe, Narumi', 'Rosen, David W.']",2021-11-04T19:26:10Z,2021-11-04T19:26:10Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90009', 'http://dx.doi.org/10.26153/16930']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['material extrusion', 'lattice structure', 'b', 'bonding strength', 'strength', 'deposition modeling', 'fracture mechanics']",Estimating Strength of Lattice Structure Using Material Extrusion Based on Deposition Modeling and Fracture Mechanics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6260c31e-a422-457e-bb6c-e34224f8bd56/download,University of Texas at Austin,"Geometrical complexity in lattice structures yields large bounding surfaces to be approximated
during additive manufacturing (AM) processes. In material extrusion, approximation of geometries using
finite-sized thin filaments introduces defects such as voids and gaps in as-fabricated geometries. This
initiates cracks between layers and increases possibility of fracture by crack propagation. As a result, a
lattice structure fabricated by material extrusion tends to fail at significantly lower stress than estimated
strength without consideration of fracture mechanism. The goal of this research is to estimate strength of
material extruded lattice structures considering bonding strength among layers. To achieve this, the
bonding strength is determined based on a deposition process modeling scheme and fracture mechanics
analysis. A two-layer deposition model is generated to investigate deposited geometry, and the effective
interlayer-bonding strength is calculated using a cohesive zone model (CZM) and peel tests. The resulting
strength is incorporated into the property-estimation procedure.",,,,,,
"['Marshall, Garrett J.', 'Thompson, Scott M.', 'Daniewicz, Steve R.', 'Shamsaei, Nima']",2021-10-26T19:10:36Z,2021-10-26T19:10:36Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89560,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'part size', 'thermal resistance', 'thermal resistance network']",Estimating the Effects of Part Size on Direct Laser Deposition Parameter Selection via a Thermal Resistance Network Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1dbd50a2-e53f-48b3-a3cc-30670758b4d9/download,University of Texas at Austin,"A mathematical model for heat transfer during the Directed Energy Deposition (DED)
process is proposed. The model employs the thermal resistance network analogy and is developed
to aid one in predicting part size effects on its temperature distribution during manufacture, and in
how to compensate such effects via suitable process parameter selection. The model predicts a
pseudo steady-state temperature response in the melt pool. The temperature variation along the
heat affected zone of a thin-walled part is estimated while assuming deposition is occurring far
from the substrate. Predicted melt pool and bulk part temperatures are validated against Laser
Engineering Net Shaping (LENSTM) experimental data obtained via a dual-wavelength pyrometer
and in-chamber infrared camera, respectively. Results demonstrate that the model may be used to
predict an average melt pool temperature. Bulk, calculated temperature distribution needs to be
further investigated to find a more suitable heat transfer coefficient surrounding the part.",,,,,,
"['Reichwein, J.', 'Geis, J.', 'Kirchner, E.']",2023-04-03T17:21:43Z,2023-04-03T17:21:43Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117722', 'http://dx.doi.org/10.26153/tsw/44601']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Laser powder bed fusion,Evaluating Concepts for the Integration of Milled Components into the Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b155ea5-f148-4594-a5c3-a8ab9a78f02d/download,,"Laser Powder Bed Fusion (L-PBF) has specific advantages over conventional 
manufacturing processes. These include high freedom in the design of components and cost-
efficient production of small quantities. However, the surface quality of components is low 
compared to milling and the production of large components is often associated with high costs. 
These challenges are addressed by integrating milled components into the L-PBF process. 
Therefore, various concepts are presented for positioning, aligning, and fastening machined 
components in the build space of the L-PBF system with the goal to provide a reliable way to start 
the L-PBF process on top of these components. Thus, allowing the potential of additive and 
subtractive manufacturing to be exploited without requiring an additional joining operation. 
Finally, these concepts are applied to a steering shaft bracket and the costs for manufacturing are 
evaluated. A 25% reduction in manufacturing costs was achieved compared to the purely additively 
manufactured component.",,,,,,
"['Hasbrouck, C.R.', 'Melnik, Samantha A.']",2024-03-27T03:57:39Z,2024-03-27T03:57:39Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124479', 'https://doi.org/10.26153/tsw/51087']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'material extrusion', 'metalcasting', 'compressive strength', 'risers', 'patterns', 'hybrid manufacturing', 'desktop printers']",EVALUATING THE COMPRESSIVE STRENGTH OF AM RISERS FOR GREEN SAND METALCASTING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/88ebe5be-677c-4091-b042-3d27a8878c49/download,University of Texas at Austin,"While many metalcasting foundries have experimented with using additive manufacturing
(AM) for patternmaking, the compressive strength of the tapered AM risers for green
sand metalcasting has not yet been explored. This study investigates the effects of infill
pattern type, infill density, and shell thickness on the compressive strength of a standard
3-inch diameter by 5-inch tall by 3-degree taper cylindrical riser manufactured with PLA
using a material extrusion process. The findings for these AM risers include plots and
mathematical models of compressive strengths at three different scales of the standard
geometry (full, three-quarters, and half), predicted build times and masses using other
common infill patterns, potential failure mechanisms during use of AM and conventionally
manufactured riser patterns, and considerations on design for both additive manufacturing
and green sand metalcasting. It is concluded that AM risers can be incorporated into and
perform well as part of conventional green sand metalcasting patterns.",,,,,,
"['Grech, I.S.', 'Wint, N.', 'Mehraban, S.', 'Sullivan, J.', 'Lavery, N.']",2021-11-18T00:20:31Z,2021-11-18T00:20:31Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90367', 'http://dx.doi.org/10.26153/tsw/17288']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['corrosion performance', 'Invar', '17-4PH', 'wrought', 'additive manufacturing', 'laser powder bed fusion', 'LPBF', 'Renishaw AM 400']",Evaluating the Corrosion Performance of Wrought and Additively Manufactured (AM) Invar ® and 17-4PH,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f68fb304-df3b-4526-9b32-5f0a1c6894ae/download,University of Texas at Austin,"A Renishaw AM 400 was used to produce Laser Powder Bed fusion (LPBF) iron alloy Invar
® and 17-4PH components. Build parameters were systematically changed and the corrosion
performance of the samples produced was investigated using a combination of scanning
vibrating electrode technique (SVET) and advanced conventional electrochemical techniques.
The results indicated that small changes in the density of the LPBF parts due to porosity
resulted in large changes to the materials corrosion susceptibility. The LPBF samples also
demonstrated significantly more variation in pitting potential measurements compared to
wrought samples indicating inhomogeneity in the built parts. References to AM samples in this
work refer to samples produced using LPBF.",,,,,,
"['Bales, Brenin', 'Smith, Tyler', 'Kim, Seokpum', 'Kunc, Vlastimil', 'Duty, Chad']",2021-12-01T23:21:45Z,2021-12-01T23:21:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90653', 'http://dx.doi.org/10.26153/tsw/17572']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['z-pinning', 'CF-PLA', 'mechanical strength', 'toughness', 'fused filament fabrication']",Evaluating the Effect of Z-pinning Parameters on the Mechanical Strength and Toughness of Printed Polymer Composite Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43fac7ab-f19d-4138-ba57-09a4f53e1a9c/download,University of Texas at Austin,"Traditional Fused Filament Fabrication methods create a mechanically anisotropic
structure that is stronger in the deposition plane than across successive layers. A recently
developed pinning process deposits continuous pins in the structure that are orientated in the
build direction across multiple layers. Initial studies of this technique have demonstrated the
ability to increase inter-layer strength and toughness. The current study evaluated various z-pinning parameters for carbon fiber reinforced polylactic acid (CF-PLA) structures, including
infill percentage, pin length, and deposition pattern. Each of these was found to affect the ability
of the z-pin to mechanically bond with the existing lattice structure and had a resulting impact on
the mechanical strength and toughness. Initial studies showed an increase in ultimate tensile
strength in the Z-axis of around 3.5x. Upon expanding the pinning settings, further studies
showed increases of over 35% from the X and Z axis ultimate tensile strength and improved
mechanically isotropic behavior.",,,,,,
"['Brackett, J.', 'Defilippis, A.', 'Smith, T.', 'Hassen, A.', 'Kunc, V.', 'Duty, C.']",2023-04-03T15:40:04Z,2023-04-03T15:40:04Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117718', 'http://dx.doi.org/10.26153/tsw/44597']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Evaluating the Mechanical Properties within the Transition Region of Multi-Material Large-Format Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/54ac5031-d934-4e5f-ab0c-c7efda58b315/download,,"Recent developments in Large-Format Additive Manufacturing (LFAM) have enabled in-
situ material changes and production of graded Multi-Material (MM) structures. The Big Area 
Additive Manufacturing (BAAM) system utilizes a dual-hopper configuration to feed different 
materials into a screw-based extruder which results in a blended material transition rather than a 
discrete material boundary, avoiding associated delamination issues. While this system enables 
site-specific material deposition at a large scale, the mechanical performance within the transition 
region needs to be evaluated to determine the impact on end-part performance. Additionally, the 
transition region can exhibit incomplete mixing, which could further influence mechanical 
performance. This study investigates the change in mechanical properties throughout the transition 
region using dynamic mechanical analysis and tensile testing of printed samples. Optical 
microscopy of the internal microstructure of the printed beads was also utilized to determine the 
influence of material blending within the transition on mechanical performance.",,,,,,
"['Rodomsky, Caitlyn', 'Conner, Brett']",2021-11-09T14:35:49Z,2021-11-09T14:35:49Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90081', 'http://dx.doi.org/10.26153/tsw/17002']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['surface roughness', 'stair step features', 'binder jetting', 'sand printing', 'metal castings']",Evaluating the Surface Finish of A356-T6 Cast Parts from Additively Manufactured Sand Molds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/833aad61-f854-4ab9-a5ac-1ef6cb4b99ed/download,University of Texas at Austin,"Binder jetting of sand allows for the design and rapid fabrication of complex molds and
cores. The surface finish of the printed molds and cores can be transferred to the cast part. A
benchmark casting was designed to compare the surface roughness and surface features of
several angles on the cast part. The benchmark casting contained surfaces with angles from 5° to
30° at 5° intervals. Benchmark castings from coated and uncoated mold surfaces were evaluated.
Angles from 5° to 20° produced a prominent stair step feature. A Keyence microscope was used
to measure the arithmetic mean roughness (Ra) and root mean square surface roughness (Rq) of
the part surfaces. These measurements are compared to a more conventional contact
profilometer. The suitability of Ra and Rq for characterizing stair step features will be discussed.",,,,,,
"['Roberson, David A.', 'Rocha, Carmen R.', 'Piñon, Monica']",2021-10-21T15:07:50Z,2021-10-21T15:07:50Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89389,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'materials characterization', 'polymer matrix composites']",Evaluation of 3D Printable Sustainable Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/32d14c1d-5192-46d9-8b83-c2745e772f63/download,University of Texas at Austin,"Polylactic acid (PLA) is rapidly becoming the mainstay material for use in desktop grade
3D printers based on FDM technology in part due to the environmental sustainability of this
polymer. While biodegradability is an advantage; as compared to other materials used by FDM-type platforms, there is a lack of desirable physical attributes. The work presented here evaluates
the altering of the physical properties of PLA through the addition of sustainable additives. Here,
the physical properties of PLA were modified while, at the same time the two desirable aspects of
3D printer compatibility and biodegradability were retained. Rheological analysis of the material
systems was performed by dynamic mechanical analysis and failure analysis of 3D printed tensile
specimens was carried out through the use of scanning electron microscopy. Finally,
biodegradability of the novel PLA-based material systems was assessed based on in-soil exposure
testing.",,,,,,
"['Carrion, Patricio E.', 'Graves, Lynne M.', 'Yampolskiy, Mark', 'Shamsaei, Nima']",2021-12-01T22:09:20Z,2021-12-01T22:09:20Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90633', 'http://dx.doi.org/10.26153/tsw/17552']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser powder bed fusion', 'AM security', 'cyber-physical attack', 'sabotage']",Evaluation of a Cyber-Physical Attack Effectiveness in Metal Additive Manufacturing by Selectively Modifying Build Layer Thickness,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0ae86437-ba24-4993-8c9c-d0e764e1c37c/download,University of Texas at Austin,"To produce functional parts satisfying required functional characteristics, Additive
Manufacturing (AM) process maintains a combination of numerous parameters within material-dependent ranges; these include power density, scanning speed, hatch distance, and layer
thickness. Unintentional misconfiguration of these parameters is easily detectable as it impacts the
entire build. In this paper, however, we consider the case of a deliberate sabotage attack which
causes misconfiguration localized to only few strategically selected layers. We propose a method
on how such targeted misconfigurations can be executed without hacking into the firmware.
Specifically, we altered a build file to mimic localized layer thickness modification by disabling
laser beam exposure, while maintaining geometrical and visual part integrity. For two distinct laser
powder bed fusion (L-PBF) systems and two metal alloys, we validated empirically the impact of
such attack on part quality and demonstrated that it can avoid detection by non-destructive
techniques (NDT). The conducted attack illustrates susceptibility of AM to deliberate sabotage
attacks and motivates the need of security solutions for this increasingly adopted manufacturing
technology.",,,,,,
"['Paterson, A.M.', 'Bibb, R.J.', 'Campbell, R.I.']",2021-10-06T21:06:27Z,2021-10-06T21:06:27Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88443', 'http://dx.doi.org/10.26153/tsw/15380']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['wrist splints', 'additive manufacturing', 'multiple-material', 'Objet Connex']",Evaluation of a Digitsed Splinting Approach with Multiple-Material Functionality Using Additive Manufacturing Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3538934-d3a2-4111-b545-eca03871f31b/download,University of Texas at Austin,"The design and fabrication of custom-made wrist immobilisation splints can be a laborious
process. In addition, patient adherence in terms of wear duration and frequency may be
affected by a range of contributing factors including poor aesthetics, hygiene issues and fit.
This paper suggests the use of additive manufacturing (AM) in a bid to resolve factors
affecting adherence and improve the efficiency of design and manufacture. Particular
attention is paid to the exploitation of multiple-material capabilities using Objet Connex
technologies, with the intent to integrate completely novel and state-of-the-art characteristics
within splints. However, in order to exploit the many benefits of AM for customised splint
fabrication, appropriate Three Dimensional (3D) Computer Aided Design (CAD)
methodologies must be considered for splint design. Furthermore, a specialised CAD
approach must be developed for splinting practitioners to allow them to create such
geometries. As a result, this paper describes the development of a customised 3D CAD
methodology for splinting practitioners to design custom-made splints, in order to evaluate
such novel features only available through AM fabrication.",,,,,,
"['Phillips, T.', 'Fish, S.', 'Beaman, J.']",2021-11-18T19:02:28Z,2021-11-18T19:02:28Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90469', 'http://dx.doi.org/10.26153/tsw/17390']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['feed-forward laser control', 'thermal control', 'in-situ', 'consistency', 'selective laser sintering']",Evaluation of a Feed-Forward Laser Control Approach for Improving Consistency in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b895af86-55ed-4269-9281-abcac4908063/download,University of Texas at Austin,"Selective Laser Sintering (SLS) is a popular industrial additive manufacturing technique
for creating functional polymer components. One of the biggest limitations today with SLS is its
poor mechanical consistency when compared with traditional manufacturing techniques, inhibiting
the use of SLS among structurally critical components. Evaluation of the SLS process has revealed
that the quality of components is strongly affected by the thermal history during the build process
and poor control over this can lead to premature part failure. This paper will discuss a novel
technique of improving in-situ thermal control by implementing a feed-forward laser controller
that uses dynamic surrogate modelling to predict optimal laser power to achieve desired thermal
characteristics. Thermal and destructive testing results will be presented showing that the
described laser power controller is capable of decreasing the standard deviations of post sintering
temperature by up to 57% and ultimate flexural strength by up to 45%.",,,,,,
"['Petros, Matthew', 'Torabi, Payman', 'Khoshnevis, Behrokh']",2021-10-12T22:34:37Z,2021-10-12T22:34:37Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88757', 'http://dx.doi.org/10.26153/tsw/15691']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Inhibition Sintering', 'SIS-metal', 'metal alloys', 'additive manufacturing', 'layer-processing', 'cross-sectional image generation scheme']",An Evaluation of Cross-Sectional Image Generation Schemes in the Selective Inhibition Sintering (SIS) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9b02fbc-f17a-47c2-bfe9-cdfe512ab78b/download,University of Texas at Austin,"Selective Inhibition Sintering of metal alloys (SIS-metal) has been proven effective in the
additive manufacture (AM) of low resolution bronze parts. The use of high precision inkjet print
heads represents a significant advancement in the SIS-metal process. The fabrication of complex
three-dimensional metallic parts requires SIS-metal compatible, cross-sectional image processing
based on the part boundary profile. Thus, three candidate layer-processing approaches were
identified and validated for rudimentary geometries. These approaches were identified from
previous research as well as preliminary investigations. The validation criteria is based upon
maintaining part integrity, the amount of powder waste produced, processing time, the ability to
handle various part geometries, and the ease of access to inhibited regions. Results are discussed
for deploying the three candidate layer processing approaches for rudimentary shapes, and a
preliminary evaluation is presented for their use on more complex geometries.",,,,,,
"['Fu, Tian', 'Sparks, Todd E.', 'Liou, Frank', 'Newkirk, Joseph', 'Fan, Zhiqiang', 'Pulugurtha, Syamala R.']",2021-09-29T14:28:04Z,2021-09-29T14:28:04Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88182', 'http://dx.doi.org/10.26153/tsw/15123']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['aircraft landing gears', 'stainless steels', 'laser cladding', 'AISI 4340']",Evaluation of Direct Diode Laser Deposited Stainless Steel 316L on 4340 Steel Substrate for Aircraft Landing Gear Application,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db3bb050-246e-4854-a97c-2b87c27d4967/download,University of Texas at Austin,"300M steel is used extensively for aircraft landing gears because of its high strength, ductility
and toughness. However, like other high-strength steels, 300M steel is vulnerable to corrosion
fatigue and stress corrosion cracking, which can lead to catastrophic consequences in the landing
gear. Stainless steels offer a combination of corrosion, wear, and fatigue properties. But for an
aircraft landing gear application a higher surface hardness is required. A laser cladding process
with fast heating and cooling rates can improve the surface hardness. AISI 4340 steel is used as a
lower cost alternative to 300M due to its similar composition. In this study, the influence of laser
cladding process parameters, shield gas, and composition of the deposition and dilution zone has
been investigated. The microstructures and composition analysis were evaluated by Scanning
Electron Microscopy (SEM) and Optical Microscopy. The deposition hardness varies from
330HV to 600HV.",,,,,,
"['Dharmadhikari, Susheel', 'Basak, Amrita']",2021-12-06T21:51:30Z,2021-12-06T21:51:30Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90685', 'http://dx.doi.org/10.26153/tsw/17604']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['fatigue failure detection', 'laser powder bed fusion', 'force-displacement sensors', 'confocal microscope']",Evaluation of Early Fatigue Damage Detection in Additively Manufactured AlSi10Mg,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fcc2295e-a558-4ca0-9990-d3b85e6da19b/download,University of Texas at Austin,"The article presents two distinct measures for fatigue damage detection in additively manufactured
AlSi10Mg specimens with a one-sided V-notch. The specimens are fabricated on a ProX-320 laser
powder bed fusion equipment with recycled AlSi10Mg powders using vetted process parameters
as suggested by 3D Systems. The process of fatigue damage evolution is monitored using two
heterogeneous sensing techniques, namely, the force-displacement sensors and a confocal
microscope. The force and displacement sensors are embedded in the fatigue testing apparatus to
capture the global effects of the stress-strain behavior of the specimens; however, it provides no
information about the local damage near the notch. The force-displacement time-series data, which
shows a hysteresis-like behavior, is calibrated using a confocal microscope focused inside the
notch of the specimen so that the onset of fatigue crack initiation can be detected at a crack opening
displacement (COD) of ~10 microns. Using the force-displacement data, the energy dissipation
rate and the material stiffness per cycle are computed. The results show a detection accuracy of
96.25% and 90.84% for the energy dissipation rate and material stiffness per cycle, respectively.
In conclusion, the paper establishes two successful predictors for fatigue damage detection in
additively manufactured AlSi10Mg specimens.",,,,,,
"['Ravichander, Bharath Bhushan', 'Jagdale, Shweta Hanmant', 'Theeda, Sumanth', 'Kumar, Golden']",2023-03-28T19:27:52Z,2023-03-28T19:27:52Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117669', 'http://dx.doi.org/10.26153/tsw/44548']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser powder bed fusion', 'Functionally Graded Lattice', 'Porosity', 'SS316L', 'part density']",Evaluation of Functionally Graded Lattice Properties of Laser Powder Bed Fused Stainless Steel 316L,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6d5f7f7c-d855-49c1-a6bb-d259ef6424ce/download,,"The development of metal Additive Manufacturing (AM) techniques, in particular the laser powder 
bed fusion (LPBF) process, has led to an increase in the innovative design and fabrication of 
lightweight and complex porous metal structures. Despite the limitations of the LPBF process 
which limits the geometric accuracy of the porous structures, it eliminates the difficulties presented 
by conventional manufacturing techniques in the fabrication of highly complex structures. The 
properties of as-built porous structures depend on the unit cell design and porosity level. These 
lightweight metal structures have applications in medical and aerospace fields. The relationships 
between the lattice geometry and performance must be determined to successfully implement the 
functional lattice designs. In this study, functionally graded lattice structures are fabricated from 
steel using SLM technique and the effect of different lattice types on the manufacturability, density 
and mechanical properties are investigated.",,,,,,
"['Ravichander, B.B.', 'Jagdale, S.H.', 'Theeda, S.', 'Kumar, G.']",2023-04-05T17:19:34Z,2023-04-05T17:19:34Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117783', 'http://dx.doi.org/10.26153/tsw/44662']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser powder bed fusion', 'Functionally Graded Lattice', 'Porosity', 'SS316L', 'Part Density']",Evaluation of Functionally Graded Lattice Properties of Laser Powder Bed Fused Stainless Steel 316L,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0600ed02-f778-4ebe-acbe-a442b8182064/download,,"The development of metal Additive Manufacturing (AM) techniques, in particular the laser powder 
bed fusion (LPBF) process, has led to an increase in the innovative design and fabrication of 
lightweight and complex porous metal structures. Despite the limitations of the LPBF process 
which limits the geometric accuracy of the porous structures, it eliminates the difficulties presented 
by conventional manufacturing techniques in the fabrication of highly complex structures. The 
properties of as-built porous structures depend on the unit cell design and porosity level. These 
lightweight metal structures have applications in medical and aerospace fields. The relationships 
between the lattice geometry and performance must be determined to successfully implement the 
functional lattice designs. In this study, functionally graded lattice structures are fabricated from 
steel using SLM technique and the effect of different lattice types on the manufacturability, density 
and mechanical properties are investigated.",,,,,,
"['Davis, T.M.', 'Crane, N.B.']",2021-12-06T22:01:53Z,2021-12-06T22:01:53Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90689', 'http://dx.doi.org/10.26153/tsw/17608']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['liquid dopants', 'liquid deposition', 'direct write', 'inkjet deposition', 'laser powder bed fusion']",Evaluation of Liquid Doping Methods for Use in Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aa7ce7f4-9089-465a-b274-f8d288b9c156/download,University of Texas at Austin,"Laser powder bed fusion (LPBF) is an additive manufacturing (AM) process that is well
known for its geometric versatility and high-quality parts. While the properties of LPBF parts are
commonly superior to those made using other AM techniques, LPBF is generally limited to a
single material in any given build. While LPBF can accommodate the integration of multiple
components into a single part geometrically, the material limitation leads to over-designing to
ensure that every component can complete their various functions. Some studies have shown
potential methods of 3D composition control throughout a part, but these methods are subject to
high cost increases due to build time increases and decreased powder recyclability. A new
approach to multi-material LPBF uses liquid dopants to alter the composition in location-specific
areas. The current study evaluates two different liquid deposition methods – direct write and inkjet
deposition – in relation to their adaptability and utility in LPBF. Inkjet deposition is shown to have
significant benefits compared to the direct write method.",,,,,,
"['Bao, Yaxin', 'Ruan, Jianzhong', 'Sparks, Todd E.', 'Anand, Jambunathan', 'Newkirk, Joseph', 'Liou, Frank']",2020-02-28T16:27:53Z,2020-02-28T16:27:53Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80116', 'http://dx.doi.org/10.26153/tsw/7137']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Microstructure,Evaluation of Mechanical Properties and Microstructure for Laser Deposition Process and Welding Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/76dc61ef-8418-431e-8cc3-02e6d298394d/download,,"Laser Aided Manufacturing Process (LAMP) can be applied to repair steel die/molds which
are currently repaired using traditional welding process in industry. In order to fully
understand the advantages of laser deposition repair process over traditional welded-repair
process, the mechanical properties such as tensile strength and hardness of H13 tool steel
samples produced by these two processes were investigated. The microstructure and fracture
surface of the samples were analyzed using optical microscope and SEM (Scanning Electron
Microscope). Moreover, depositions on substrates with different shapes were studied to
evaluate the performance of LAMP on damaged parts with complicated geometric shape.",,,,,,
"['Li, Xiaoxuan', 'Crocker, James E.', 'Geiss, Erik', 'Shaw, Leon L.', 'Marcus, Harris L.', 'Cameron, Thomas B.']",2019-09-23T15:23:05Z,2019-09-23T15:23:05Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75934', 'http://dx.doi.org/10.26153/tsw/3033']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Restoration,Evaluation of Microstructure and Properties for Multi-Materials Laser Densification of Dental Restoration 159,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15c19fbb-1436-44a4-8bc4-cabd594dfc32/download,,"Traditional dental restorations are produced by the porcelain-fused-to-metal (PFM) process, in which a dental restoration is cast from a metallic alloy and then covered with dental porcelains by several firing processes, which is both labor intensive and expensive. In this paper, the feasibility of dental restorations is investigated using a multi-materials laser densification
(MMLD) process. To evaluate the effectiveness of the MMLD process, nickel powders and commercial dental porcelain powders are laser densified using YAG and CO2 lasers respectively. Effects of processing parameters, e.g. laser scanning rate and target temperature, are evaluated and the microstructure of processed nickel and porcelain materials are characterized for the
optimization of laser densification. Results indicate that densities of laser processed nickel and dental porcelain are strongly dependent of processing parameters. Fully dense layers are achievable with proper processing conditions.",,,,,,
"['Cansizoglu, O.', 'Cormier, D.', 'Harryson, O.', 'West, H.', 'Mahale, T.']",2020-02-28T15:13:56Z,2020-02-28T15:13:56Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80110', 'http://dx.doi.org/10.26153/tsw/7131']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Powder metallurgy,An Evaluation of Non-Stochastic Lattice Structures Fabricated Via Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0642ebfb-8c89-4b55-b4d3-9ec733cc2a1e/download,,"Metal foam structures have many applications and can be used as structural supports, heat
exchangers, shock absorbers, and implant materials. Stochastic metal foams having different cell
sizes and densities have been commercially available for a number of years. This paper addresses
a different type of foams which are known as non-stochastic foams, or lattice structures. These
foams have a well defined repeating unit cell structure rather than the random cell structure in
commercially available stochastic foams. The paper reports on preliminary research on the
fabrication of non-stochastic Ti-6Al-4V alloy foams using the Electron Beam Melting process.
Behavior of the structures in compression, bending, and low cycle repeating load tests are
discussed, and recommendations about cell geometry and processing conditions are made.",,,,,,
"['Nussbaum, Justin', 'Craft, Garrett', 'Harmon, Julie', 'Crane, Nathan']",2021-10-27T22:29:06Z,2021-10-27T22:29:06Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89633,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['heating rates', 'exposure times', 'sintering levels', 'nylon 12', 'selective laser sintering']",Evaluation of Processing Variables in Large Area Polymer Sintering of Single Layer Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db3c9c28-1d85-4941-a0c2-666db1e023da/download,University of Texas at Austin,"As the additive manufacturing (AM) industry continues to boom, the material palette
continues to grow. However, the materials applicable to selective laser sintering (SLS) remains
limited. Typically, the scanning laser beam heats each location for milliseconds at a time with a
very high heating flux followed by quick cooling. This can create large temperature gradients and
high local temperatures. Many polymers will degrade or fail to densify under these conditions.
Due to the economic constraints for point processing, little work has been done to evaluate the
sintering process with lower intensities, longer exposure times and larger areas than are typical
with conventional SLS. We will report on a new method for simultaneously heating large areas
with spatially-controlled heat flux. A demonstration system and test material is presented and
characterized. It is then used to evaluate the relationships between heating rates, exposure time,
and resulting sintering levels for traditional Nylon 12 powders in single layer parts.",,,,,,
"['Agarwal, Kuldeep', 'Mathur, Deepanker', 'Shiypuri, Rajiv', 'Lembo, John']",2019-10-24T17:52:25Z,2019-10-24T17:52:25Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77408', 'http://dx.doi.org/10.26153/tsw/4497']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Prometal,Evaluation of PROMETAL Technique for Application to Dies for Short Run Forgings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4bdbb249-83a8-4804-812a-da5d98c01735/download,,"Manufacturing of hot forging dies required several steps such as acquisition of material
block, shaping it for machining, rough machining the cavity, heat treating, finish machining,
grinding and polishing. This process takes several months. Consequently for limited number of
parts often required in aerospace industry, forging is being replaced by direct machining of parts.
If the die lead times (administrative and manufacturing) could be reduced to weeks instead of
months, forging process will become viable for short run forgings. This paper evaluates the
PROMETAL technique for dies in forging of aluminum alloys. This evaluation includes
frictional, heat transfer and strength characterization. Isothermal and non-isothermal ring tests
together with FEM models are used to determine the interface behavior and its effect on metal
flow.",,,,,,
"['Merschroth, H.', 'Harbig, J.', 'Weigold, M.', 'Geis, J.', 'Kirchner, E.']",2023-04-03T17:32:18Z,2023-04-03T17:32:18Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117724', 'http://dx.doi.org/10.26153/tsw/44603']",eng,2022 International Solid Freeform Fabrication Symposium,Open,powder bed fusion,Evaluation of Solidification in Powder Bed Fusion Using a High Speed Camera,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03b140d1-8b98-4600-8a5d-9cbb93c2f881/download,,"Powder bed fusion using a laser beam (PBF-LB) [1] enables geometrical design freedom 
to build parts for optimized functionality. Furthermore, PBF-LB allows microstructural design 
freedom. By controlling the solidification behavior microstructural adaptions can be made to obtain 
the full potential of the material. As the solidification rates and the thermal gradient depend on the 
local part geometry, new data-driven approaches, e.g. machine learning (ML), seem to be suitable 
for local microstructural adaptions. In this work an evaluation concept to analyze the thermal melt 
pool characteristics based on a high-speed camera is developed. The thermal radiation intensity of 
the melt pool is used to derive the thermal gradient and combined with an image rate of 41,000 fps 
the solidification rate is derived. The developed approach provides local data of the solidification 
for ML-based process adaptions but also serves for part individual quality assurance tasks.",,,,,,
"['Weiss, C.', 'Boedger, C.', 'Schiefer, E.', 'Heussen, D.', 'Haefner, C.L.']",2023-03-30T16:14:22Z,2023-03-30T16:14:22Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117699', 'http://dx.doi.org/10.26153/tsw/44578']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Laser powder bed fusion,Evaluation of the Ecological Footprint for Parts from AlSi10Mg manufactured by Laser  Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eaaebdc5-c0e7-47c0-a6e7-f6f0324e96d9/download,,"The manufacturing industry contributes immensely to the global emissions and therefore is 
a key factor that has to be addressed when a more sustainable production is desired. Laser Powder 
Bed Fusion (LPBF) is an AM technique that offers the possibility to manufacture metal parts in a 
more material efficient way due to the layer-by-layer build-up. Nevertheless, the processing chain 
for parts from LPBF contains additional steps like powder atomization, which also influence the 
ecological footprint of the production chain. Within this work, a life-cycle model for the production 
step of parts from AlSi10Mg powder material is developed. The model is supplied with data from 
the powder atomization up to the production step, either by literature, database or experimental 
measurements during production. The footprint in terms of CO2 emissions is then analyzed and 
emission-intense steps are identified. Two manufacturing scenarios are considered to evaluate the 
sensitivity on the emissions.",,,,,,
"['Agarwala, Mukesh K.', 'Bourell, David L.', 'Wu, Benny', 'Beaman, Joseph J.']",2018-05-03T18:47:39Z,2018-05-03T18:47:39Z,1993,Mechanical Engineering,doi:10.15781/T29P2WQ0P,http://hdl.handle.net/2152/65058,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['SLS process', 'Center for Materials Science and Engineering', 'Department of Mechanical Engineering', 'Rapid Prototyping']",An Evaluation of the Mechanical Behavior of Bronze-NI Composites Produced by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ffeac1b8-0d35-44b3-8fda-e63ac22e8ee5/download,,"Mechanical properties of Bronze-Nickel composites produced by Selective Laser Sintering (SLS)
were evaluated by constant displacement tension tests. These were studied as a function of SLS
process parameters - laser power density, scan speed, scan spacing, scan direction and layer
thickness. The strength data was then correlated to the microstructure and the part bulk density. To
further enhance the part densities and the mechanical properties, post-SLS sintering was studied.
The relationships between SLS process parameters, post-SLS sintering parameters and the
resulting microstructures, part bulk density and the mechanical properties will be described.",,,,,,
"['Price, Steven', 'Cooper, Ken', 'Chou, Kevin']",2021-10-06T21:30:51Z,2021-10-06T21:30:51Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88450', 'http://dx.doi.org/10.26153/tsw/15387']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['electron beam additive manufacturing', 'near-infrared thermography', 'powder-based manufacturing']",Evaluations of Temperature Measurements By Near-Infrared Thermography in Powder-Based Electron-Beam Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/847dfddf-7941-4fc6-9bd6-75b35838c7b5/download,University of Texas at Austin,"Powder-based electron beam additive manufacturing (EBAM) has gained increased usage
in different industries. Process monitoring such as temperatures may offer important information.
However, temperature measurements in EBAM are challenging because of high temperature
ranges, extreme gradients and fast transient response.
In this study, temperature measurements during the EBAM process, in particular, around
the electron beam scanning area, were attempted using a near-infrared thermal camera. The
obtained temperature data demonstrated the feasibility of such a measuring technique. The
thermal camera was able to capture the pre-heating, contour melting, and hatch melting events.
Further, the achievable spatial resolution is around 12 µm when using a 350 mm lens.",,,,,,
"['Moi, Matthias', 'Lindemann, Christian', 'Jahnke, Ulrich', 'Koch, Rainer']",2021-10-11T21:39:29Z,2021-10-11T21:39:29Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88653', 'http://dx.doi.org/10.26153/tsw/15587']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'event-driven software architecture', 'cost assessment', 'traceability', 'Quality Management']",An Event-Driven Software Architecture for Process Analysis in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6145b62c-1c0d-4f8f-8f73-f3ccb2d3bb26/download,University of Texas at Austin,"Additive Manufacturing is still not commonly accepted as a considerable manufacturing
process for serial products. Build rate and cost estimation or even the traceability of parts
concerning Quality Management issues is weak. That's also because of the unavailability of
adequate software solutions. Self-made solutions with Spreadsheets are often hard to adapt
and inflexible in usage. This paper presents a distributed event-driven software architecture
for cost assessment and traceability from powder to finished products. Further the approach of
event-driven processing for cost calculation following the activity based costing methodology
is discussed. The methodology considers arbitrary events (e.g. machine data or market prices)
that may have an effect for a more detailed process analysis.",,,,,,
"['Gibert, James M.', 'McCullough, Daniel T.', 'Fadel, Georges M.', 'Jonhson, Kenneth E.']",2021-10-05T19:50:15Z,2021-10-05T19:50:15Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88420', 'http://dx.doi.org/10.26153/tsw/15359']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic consolidation', 'build height', 'support materials', 'tin bismuth', 'candy']",Examination of Build Height in Ultrasonic Consolidation for Foil Width Specimens Using Supports,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d1629479-ad03-4c01-8776-8a40b2555991/download,University of Texas at Austin,"Ultrasonic consolidation (UC) is a novel, solid-state, additive manufacturing
fabrication process. It consists of ultrasonic joining of thin metal foils and contour milling
to directly produce functional components in a variety of geometries. The bond between
layers forms when an ultrasonic horn creates a local oscillating stress field at the mating
surfaces. It is commonly theorized that the high frequency vibration under pressure
produces a metallurgical bond without melting the base material. The mechanism behind
the bond is believed to be due to interfacial motion and friction that disrupts surface
contaminants, arguably allowing direct metal to metal contact, and producing sufficient
stress to induce plastic flow and promote the growth of grains across the mating surfaces.
Ignored in this explanation is the role of substrate dimensions on the quality and strength
of the joining process. Researchers have previously examined the effective height
limitations of the build process, i.e., the limiting height to width ratio of one of the
component features being fabricated. This paper extends the experimental work on using
support materials to extend build height on specimens using two different candidate materials, tin bismuth, and a mixture of sugar, corn syrup, and water, referred to as
“candy”. Tin bismuth and candy the represent the extremes of a tradeoff between
convenience and stiffness that a support material must possess.",,,,,,
"['Link, Martin', 'Haefele, Tobias', 'Abele, Eberhard']",2021-11-09T16:34:33Z,2021-11-09T16:34:33Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90107', 'http://dx.doi.org/10.26153/tsw/17028']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['316L', 'steel powder', 'stainless-steel base bodies', 'selective laser melting', 'additive manufacturing', 'conventional manufacturing']",Examination of the Connection Between Selective Laser-Melted Components of 316L Steel Powder on Conventionally Fabricated Base Bodies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5b7a910-44ee-4821-be06-88908df06bc6/download,University of Texas at Austin,"The advantages of selective laser melting lie in the production of complex, small
components in small batches. For large-volume components, the use of additive manufacturing
(AM) processes is limited by the available installation space, low build rates, and high material
costs. For the production of large and less complex workpieces, conventional manufacturing
processes such as milling are more economical. The background of this study was to combine both
processes to decrease manufacturing times. For this purpose, a body made of 316L (1.4404) steel
powder was printed using selective laser melting on conventionally manufactured stainless-steel
base bodies. The use of multi-materials enables optimized machinability in the respective
manufacturing process. This paper examines the hardness properties of multi-material samples and
uses micrographs to analyze the microstructure of their connection area. A complete connection
between hybrid components made of comparable materials was determined.",,,,,,
"['Pichler, T.', 'Schleifenbaum, J.H.']",2021-11-18T18:21:16Z,2021-11-18T18:21:16Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90455', 'http://dx.doi.org/10.26153/tsw/17376']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['process control', 'process parameters', 'geometries', 'thermal imaging', 'Ti6Al4V', 'LPBF']",Examination of the LPBF Process by Means of Thermal Imaging for the Development of a Geometric-Specific Process Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f88a0473-ed4b-4406-a4b8-2480b01f2cff/download,University of Texas at Austin,"The development of process parameters for the Laser Powder Bed Fusion (LPBF) process
is typically carried out by the manufacturing and metallurgical analysis of geometrically primitive
test specimens (e.g. cubes). The process parameters identified in this way are used for the
manufacturing of parts which are characterized by a high geometric complexity and a combination
of solid and filigree component areas. Due to the discrepancy between the parameter development
on primitive specimens and applications with complex parts, a geometric-specific process control
is to be developed. In the context of this work different sample geometries are manufactured from
Ti6Al4V by LPBF and the process is monitored by thermal imaging. The influence between
component geometry and process parameters on the thermal behavior is shown.",,,,,,
"['Eschey, C.', 'Lutzmann, S.', 'Zaeh, M.F.']",2021-09-28T20:04:51Z,2021-09-28T20:04:51Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88169', 'http://dx.doi.org/10.26153/tsw/15110']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'powder spreading', 'additive layer manufacturing']",Examination of the Powder Spreading Effect in Electron Beam Melting (EBM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4c0f1e6-cfd3-41c0-8c65-1b33750e950b/download,University of Texas at Austin,"In recent years, the scientific and industrial relevance of Electron Beam Melting (EBM) has
grown. This is mainly due to the electron beam’s extensive power density and flexible
positioning properties. Thus, considerable building rates as well as a favorable part quality can be
realized. However, the appearance of transient physical effects constitutes a substantial drawback
towards the broader use of the technology. Therefore, experimental examinations are being
carried out in order to investigate the effect of sudden powder spreading during beam material
interaction. Based on an existing mathematical model, an analytical approach is formulated in
order to implement effective counter measures. Hence, a significant increase in process stability
is being achieved as the undesirable powder spreading effect is being avoided securely.",,,,,,
"['Betts, J. Logan', 'Downs, Will', 'Dantin, Matthew J.', 'Priddy, Matthew W']",2023-02-09T15:42:42Z,2023-02-09T15:42:42Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117435', 'http://dx.doi.org/10.26153/tsw/44316']",eng,2022 International Solid Freeform Fabrication Symposium,Open,GPU,Examining the GPU Acceleration Speed-Up for Finite Element Modeling of Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c004ad59-d8d5-4f4b-abf5-92eea1458740/download,,"Using a graphics processing unit (GPU) in addition to a central processing unit (CPU) has demonstrated 
promise for the acceleration of processing-intensive operations such as finite element (FE) simulations. 
Commercial FE solvers have begun to utilize GPU acceleration for classical multi-physics applications, but the 
speed-up for additive manufacturing (AM) simulations is not well understood. There is a significant need for 
GPU acceleration for metal-based AM FE simulations, which are computationally expensive because of the high 
mesh densities and the large number of time increments employed. This study examines the efficacy of GPU 
acceleration for Abaqus AM simulations, where benchmark simulations using a sequentially coupled FE thermo-
mechanical model are run both with and without GPU acceleration. The speed-up is compared across the AM 
process for the thermal and mechanical analysis. In this study, GPU acceleration provided the ability to decrease 
simulation runtime by two-to-four times on 4-8 CPU cores, and one-to-two times on 16-32 CPU cores.",,,,,,
"['Barclift, Michael W.', 'Williams, Christopher B.']",2021-10-06T22:31:22Z,2021-10-06T22:31:22Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88460', 'http://dx.doi.org/10.26153/tsw/15397']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Objet', 'PolyJet', 'design of experiments', '3D printing']",Examining Variability in the Mechanical Properties of Parts Manufactured via PolyJet Direct 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1a95fb2-f9fe-4c3d-8764-3a0f5a5ee387/download,University of Texas at Austin,"In Objet’s PolyJet process, part layers are created by selectively inkjetting photopolymers
onto a build substrate and then cured with ultraviolet lamps. With an eye towards using PolyJet
as a manufacturing process to fabricate end-use products, the authors examine the sensitivity of
part material properties to variation in process parameters. Specifically, a design of experiments
is conducted using a full-factorial design to analyze the effects of three parameters on the
specimens’ tensile strength and tensile modulus: the in-build plane part orientation (X-Y), the
out-of-build plane part orientation (Z), and the distance between specimens. Results show that
part spacing has the largest effect on the tensile strength, but the three parameters produced no
statistically significant effects on the tensile modulus. Orienting specimens in XZ orientation
with minimal part spacing resulted in the highest tensile strength and modulus. Whereas,
orienting specimens in the YZ orientation at the farthest part spacing led to the lowest
mechanical properties.",,,,,,
"['Sudbury, Zeke', 'Duty, Chad', 'Kunc, Vlastimil']",2021-11-02T18:04:42Z,2021-11-02T18:04:42Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89845,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['material property space map', 'functionally graded materials', 'big area additive manufacturing', ""Ashby's concept""]",Expanding Material Property Space Maps with Functionally Graded Materials for Large Scale Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb59ac73-d1cf-46c8-8bdb-382c068514ff/download,University of Texas at Austin,"Big Area Additive Manufacturing (BAAM) is a large scale extrusion-based print system that
exceeds the throughput of conventional printers by five hundred times. In addition, BAAM uses
pelletized feedstocks, which allows for site-specific definition of material composition and
provides an unprecedented variety of material options. This study applies Ashby’s concept of a
material property space map to a variety of materials suitable for printing on BAAM. Ashby
maps plot the performance of various materials across multiple parameters (such as strength,
density, stiffness, etc) allowing for direct comparison of non-dimensional performance criteria.
This study uses Ashby maps to identify opportunities for the use of functionally graded materials
on BAAM to achieve structural performance not yet available with conventional printers and
homogeneous materials.",,,,,,
"['Lopes, Amit', 'Navarrete, Misael', 'Medina, Francisco', 'Palmer, Jeremy', 'MacDonald, Eric', 'Wicker, Ryan']",2020-03-05T19:43:41Z,2020-03-05T19:43:41Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80148', 'http://dx.doi.org/10.26153/tsw/7169']",eng,2006 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,Expanding Rapid Prototyping for Electronic Systems Integration of Arbitrary Form,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7253996a-e186-4bbe-b18b-f25bca92b0c3/download,,"An innovative method for rapid prototyping (RP) of electronic circuits with components
characteristic of typical electronics applications was demonstrated using an enhanced version of
a previously developed hybrid stereolithography (SL) and direct write (DW) system, where an
existing SL machine was integrated with a three-axis DW fluid dispensing system for combined
arbitrary form electronic systems manufacturing. This paper presents initial efforts at embedding
functional electronic circuits using the hybrid SL/DW system. A simple temperature-sensitive
circuit was selected, which oscillated an LED at a frequency proportional to the temperature
sensed by the thermistor. The circuit was designed to incorporate all the required electronic
components within a 2.5” x 2” x 0.5” SL part. Electrical interconnects between electronic
components were deposited on the SL part with a DW system using silver conductive ink lines.
Several inks were deposited, cured, and tested on a variety of SL resin substrates, and the E 1660
ink (Ercon Inc, Wareham, MA) was selected due to its measured lowest average resistivity on
the SL substrates. The finished circuit was compared with Printed Circuit Board (PCB)
technology for functionality. The electronic components used here include a low voltage battery,
LM 555 timer chip, resistors, a thermistor, capacitors, and Light Emitting Diodes (LEDs). This
circuit was selected because it (1) represented a simple circuit combining many typically used
electronic components and thus provided a useful demonstration for integrated electronic
systems manufacturing applicable to a wide variety of devices, and (2) provided an indication of
the parasitic resistances and capacitances introduced by the fabrication process due to its
sensitivity to manufacturing variation. The hybrid technology can help achieve significant size
reductions, enable systems integration in atypical forms, a natural resistance to reverse
engineering and possibly increase maximum operating temperatures of electronic circuits as
compared to the traditional PCB process. This research demonstrates the ability of the hybrid
SL/DW technology for fabricating combined electronic systems for unique electronics
applications in which arbitrary form is a requirement and traditional PCB technology cannot be
used.",,,,,,
"['Roberson, D.A.', 'Shemelya, C.M.', 'MacDonald, E.', 'Wicker, R.B.']",2021-10-13T19:33:07Z,2021-10-13T19:33:07Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88769', 'http://dx.doi.org/10.26153/tsw/15703']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'materials characterization', 'polymer matrix composites']",Expanding the Applicability of FDM-type Technologies Through Materials Development,Conference paper,https://repositories.lib.utexas.edu//bitstreams/30194075-adab-4942-a703-68dd20871094/download,University of Texas at Austin,"Currently, the most common form of additive manufacturing is material extrusion 3D
printing (ME3DP) based on fused deposition modeling (FDM®) technology which relies upon a
thermoplastic monofilament as a base material for the fabrication of three dimensional objects.
The dependence on thermoplastics as a feedstock by ME3DP platforms limits the applicability of
this additive manufacturing method. A clear-cut path towards greater applicability is the
introduction of novel materials with diverse physical properties which maintain compatibility
with 3D printing platforms based on FDM® technology. The work in this paper presents efforts
in the development of polymer matrix composites (PMC)s and polymer blends based on
acrylonitrile butadiene styrene (ABS) and polycarbonate (PC), two thermoplastic materials
commonly used by FDM®-type platforms. Mechanical testing and fractography via scanning
electron microscopy (SEM) were the two main metrics used to characterize these new material
systems. Overcoming barriers to the manufacturing of these novel 3D-printable materials
systems is also presented.",,,,,,
"['Lough, Cody S.', 'Landers, Robert G.', 'Bristow, Douglas A.', 'Drallmeier, James A.', 'Brown, Ben', 'Kinzel, Edward C.']",2021-12-07T17:25:26Z,2021-12-07T17:25:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90729', 'http://dx.doi.org/10.26153/tsw/17648']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['thermal modeling', 'superposition', 'laser powder bed fusion', 'LPBF']",Experiment Based Superposition Thermal Modeling of Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/84948207-9068-416a-804a-06c9ca36037a/download,University of Texas at Austin,"This paper evaluates experiment-based superposition thermal modeling for Laser Powder
Bed Fusion (LPBF) with a pulsed laser. An analytical pulsed laser thermal model establishes the
modeling procedure. The framework inverts a powder bed’s single pulse temperature response
from experimental spatiotemporal Short-Wave Infrared (SWIR) camera data. Superimposing this
response along a scan path simulates multi-pulse LPBF. Results show the experimentally informed
superposition model rapidly and accurately predicts a layer’s temperature history. The model has
applications in correction of thermally driven LPBF errors and in-situ part qualification.",,,,,,
"['Kjer, Magnus Bolt', 'Zwicker, Moritz Reinhard Ludwig', 'Nadimpalli, Venkata Karthik', 'Andersen, Sebastian Aagaard', 'Pedersen, David Bue']",2023-01-27T14:27:33Z,2023-01-27T14:27:33Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117340', 'http://dx.doi.org/10.26153/tsw/44221']",eng,2022 International Solid Freeform Fabrication Symposium,Open,gas flow,Experimental Analysis and Optimization of Gas Flow in an Open-Architecture Metal L-PBF System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0662b13b-ef7f-46e2-a86e-918096f117cb/download,,"A sensor platform for experimental in-situ characterization of metal laser powder bed fusion (L-
PBF) is developed and used to analyze the gas flow across the powder bed. The gas flow in metal
L-PBF is crucial to attaining transient and spatially consistent results. The gas flow removes spatter
from the welding process as well as the plume consisting of metal condensate. Defects like porosity
will result from these process byproducts not being removed. A CNC gantry with a flow sensor
mounted measured the gas velocity across the process area. The automated measurements were
analyzed and used to improve the gas flow by changing the inlet geometry. The method can be used
as a supplement to computational fluid dynamics, as well as a calibration tool for simulations, to
improve the efforts toward better models of the metal L-PBF process.",,,,,,
"['Alkunte, Suhas', 'Fidan, Ismail', 'Hasanov, Seymur']",2023-01-20T16:38:53Z,2023-01-20T16:38:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117263', 'http://dx.doi.org/10.26153/tsw/44144']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Functionally Graded Materials (FGM)', 'Tensile', 'Fatigue']",Experimental Analysis of Functionally Graded Materials produced by Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2fd4ce0e-25fc-43bd-bef3-c6f7bd2a4191/download,,"Multi-material additive manufacturing has grabbed tremendous attention in the research 
community. In this investigation, a multi-material single extrusion system was used to fabricate 
the combination of chopped carbon fiber reinforced Polyethylene Terephthalate Glycol (CF-
PETG) and Thermoplastic Polyurethane (TPU) materials with gradient transition for a more robust 
material interface. Various patterns such as the 20, 40, 60, and 80% by volume blend of CF-PETG 
and TPU materials are designed, printed, and analyzed to understand their tensile and fatigue 
behaviors. Tensile–tensile fatigue tests with a stress ratio of 0.1 were performed on each specimen 
at 80% of UTS. The characterization of functionally gradient material interface and direct 
transition patterns were conducted for comparison. The results showed that gradient change in 
material concentrations from soft to hard material has significantly enhanced the interface strength.",,,,,,
"['Gribbins, Cassandra', 'Steinhauer, Heidi M.']",2021-10-19T15:29:12Z,2021-10-19T15:29:12Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89300,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['acrylonitrile butadiene styrene', 'ABS living hinge', 'plastic behavior', 'additive manufacturing']",Experimental Analysis on an Additively Manufactured ABS Living Hinge,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b492148-8868-45d2-950f-a3b6a938d4a9/download,University of Texas at Austin,"A study on the plastic behavior of an additively manufactured acrylonitrile butadiene
styrene (ABS) living hinge was conducted using a MakerBot 2X. Initial research included
numerical and analytical linear analyses on a typical living hinge design. This paper introduces the
portion of the research that explores the application of traditional design practices to entry-level
additive manufacturing machines. Tensile testing for material properties was conducted to refine
the numerical model. Experimental rotational testing was conducted for data on the non-linear,
plastic behavior experienced during application. Verification of the numerical model with
experimental results will be used to guide future work on exploring alternate design geometries
that leverage the advantages of additive manufacturing’s design freedom for smoother stress
distribution on the hinge.",,,,,,
"['Fotovvati, B.', 'Shrestha, S.', 'Ferreri, N.', 'Duanmu, N.']",2024-03-26T20:47:24Z,2024-03-26T20:47:24Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124405', 'https://doi.org/10.26153/tsw/51013']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'area printing', 'thermo-fluid modeling', 'Inconel 718', 'M300 maraging steel']",Experimental and Computational Study of Area Printing™ Additive Manufacturing: Inconel 718 and M300 Maraging Steel Density Improvement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2f7388e-9b9a-4db2-801c-e609b537f8a4/download,University of Texas at Austin,"The low manufacturing speed of laser-powder bed fusion (LPBF) additive manufacturing
has hindered its adoption in conventional manufacturing methods. Large-area pulsed laser powder
bed fusion (LAPBF), also known as ""Area Printing™"", has addressed this limitation by replacing
the point laser with a large-area pulsed laser. Each pulse melts a region of the powder bed in the
order of square millimeters, which enables scalability without the sacrifice of resolution and high
throughput at an equivalent or better quality (in part due to a lack of spatter) when compared to
conventional LPBF methods. In this study, process parameters are optimized to achieve near-fulldensity parts, and a computational model is developed to understand the multi-physics governing
the process. It is observed that the shallow depth and high aspect ratio of the melt pool lead to a
unidirectional solidification front extending along the build direction where grains grow
epitaxially, and highly directional microstructures are created.",,,,,,
"['Dong, Guoying', 'Ding, Yuchen', 'Teawdeswan, Ladpha', 'Luo, Chaoqian', 'Yu, Kai']",2023-02-24T14:56:54Z,2023-02-24T14:56:54Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117527', 'http://dx.doi.org/10.26153/tsw/44407']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Finite Element Analysis', 'Heterogeneous Structure', 'Lattice  Structure']",Experimental and Numerical Analysis of Lattice Structures with Different Heterogeneities,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a6dff8f4-c725-496d-9534-f364f366767c/download,,"Lattice structures with optimized material distributions can achieve unique mechanical 
properties such as high stiffness-to-weight ratio. However, the numerical analysis of the 
mechanical properties of heterogeneous lattice structures is challenging. In this research, three 
numerical approaches, including the beam element model, tetrahedral element model, and two-
stage homogenization model, were used to predict the stiffness of lattice structures with different 
heterogeneities. Compression tests were conducted to evaluate the accuracy of the simulation 
results of each numerical approach. It was found that the accuracy of the numerical model varies 
with the increasing of heterogeneities. The beam element model significantly underestimated the 
stiffness. The tetrahedral element model is the most accurate, but the computational cost is 
extremely higher than others. The results also indicated that, although the homogenization-based 
numerical model can substantially reduce the computational cost, the accuracy can be 
compromised due to the heterogeneity of lattice structures.",,,,,,
"['Pokkalla, Deepak Kumar', 'Turner White, Brandon', 'Wang, Jier', 'Spencer, Ryan', 'Panesar, Ajit', 'Kim, Seokpum', 'Vaidya, Uday']",2024-03-27T04:00:11Z,2024-03-27T04:00:11Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124480', 'https://doi.org/10.26153/tsw/51088']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['triply periodic minimal surface', 'lattice structures', 'additive manufacturing']",Experimental and Numerical Investigations on Dynamic Mechanical Properties of TPMS Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ca63eef-e677-4b31-8b52-61f59e7e4084/download,University of Texas at Austin,"Triply Periodic Minimal Surface (TPMS) lattice structures have been of increasing interest due to their
light weighting, enhanced mechanical properties, and energy absorption characteristics for automotive
and biomedical applications. With the advent of additive manufacturing and geometric modeling
software, TPMS lattices with complex geometries can be realized. In this work, TPMS lattice structures
were fabricated with PLA using fused filament fabrication (FFF) and their dynamic properties are
characterized through drop tower experiments. Although lightweight TPMS lattices are beneficial for
their impact absorption capability, most of the existing works are limited to quasi-static compression,
and dynamic impact tests are rarely performed. The current study investigates the stress-strain and
energy absorption characteristics of TPMS lattices through drop tower testing and numerical modeling.
Finite element modeling for TPMS lattices is carried out to validate the experimental responses. The
mechanical properties, deformation, and failure mechanisms of TPMS lattices under dynamic impact
are summarized for potential future applications.",,,,,,
"['Santosa, James', 'Jing, Dejun', 'Das, Suman']",2019-10-30T16:53:27Z,2019-10-30T16:53:27Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78192', 'http://dx.doi.org/10.26153/tsw/5281']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Multi-Material Deposition,Experimental and Numerical Study on the Flow of Fine Powders from Small-Scale Hoppers Applied to SLS Multi-Material Deposition-Part I,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb723c59-40d9-4dea-ba31-e76e88bea4b7/download,,"We present experimental guidelines for the delivery of powders under 100µm through
hopper-nozzle orifice diameters on the order of 1mm. Small-scale hoppers will be incorporated
into an SLS powder deposition system for creating thin layers of multiple powdered materials in
a patterned bed. This is a preliminary investigation on the flow behavior for selected orifice
diameters and particle sizes under gravity or low pressure-assisted flow conditions. A method for
numerically modeling the gas-particle behavior in hopper-nozzles is presented and conditions for
achieving continuous mass flow rates are demonstrated.",,,,,,
"['Bansal, R.', 'Acharya, R.', 'Gambone, J.J.', 'Das, S.']",2021-10-05T13:51:58Z,2021-10-05T13:51:58Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88372', 'http://dx.doi.org/10.26153/tsw/15311']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['scanning laser epitaxy', 'Georgia Institute of Technology', 'nickel-based superalloys']",Experimental and Theoretical Analysis of Scanning Laser Epitaxy Applied to Nickel-Based Superalloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3539553-f62d-4ab0-ad05-07f891c2c979/download,University of Texas at Austin,"This paper reports on the experimental development and the theoretical analysis of the
scanning laser epitaxy (SLE) process that is currently being investigated and developed at the
Georgia Institute of Technology. SLE is a laser-based manufacturing process for deposition of
equiaxed, directionally solidified and single-crystal nickel superalloys onto superalloy substrates
through the selective melting and re-solidification of superalloy powders. The thermal modeling
of the system, done in a commercial CFD software package, simulates a heat source moving over
a powder bed and considers the approximate change in the property values for consolidating
CMSX-4 nickel superalloy powder. The theoretical melt depth is obtained from the melting
temperature criteria and the resulting plots are presented alongside matching experimental
micrographs obtained through cross-sectional metallography. The influence of the processing
parameters on the microstructural evolution, as evidenced through observations made from the
micrographs, is discussed.","This work is sponsored by the Office of Naval Research, through
grants N00173-07-1-G031 and N00014-10-1-0526.",,,,,
"Yang, Li",2021-10-13T20:36:49Z,2021-10-13T20:36:49Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88780', 'http://dx.doi.org/10.26153/tsw/15714']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['3D reticulate cellular structure', '3D octahedral cellular structure', 'additive manufacturing']",Experimental Assisted Design Development for a 3D Reticulate Octahedral Cellular Structure using Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b8e6204-1d9a-4e57-bc22-34aede4f0579/download,University of Texas at Austin,"Traditionally it has been difficult to develop and verify designs for 3D reticulate cellular structure.
Additive manufacturing provided a feasible alternative for this challenge. In this work, a 3D octahedral
cellular structure was designed and investigated. Using a combined method of simulation and
experimentation, the mechanical properties of the structures were evaluated. It was found that the cellular
structure exhibits unusual size effect that is highly predictable by simulation and experimentation. This
work established the design-property mapping for the octahedral cellular structure for further design
development, and demonstrated the feasibility of applying this type of structure in sandwich panel
applications.",,,,,,
"['Dibua, Obehi G.', 'Yuksel, Anil', 'Roy, Nilabh K.', 'Foong, Chee S.', 'Cullinan, Michael']",2021-11-11T16:48:01Z,2021-11-11T16:48:01Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90245', 'http://dx.doi.org/10.26153/tsw/17166']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['nanoparticle', 'sintering time', 'calibration', 'simulation', 'microscale selective laser sintering']",Experimental Calibration of Nanoparticle Sintering Simulation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cee129c6-061a-447d-9bd8-e669184a9c5c/download,University of Texas at Austin,"Microscale Selective Laser Sintering models have been built as a basis to predict the
properties of sintered nanoparticles under isothermal heating. These models use Phase Field
Modelling (PFM) to track the diffusion of nanoparticles, resulting in properties such as the change
in relative density and shrinkage of the sintered bed with time. To ensure the accuracy of these
PFM models, experimental validation has to be done. This paper presents the experimental
procedure and results for isothermally heating nanoparticles up to 450 – 600°C, at sintering times
varying from 1 to 45 minutes. Measurement uncertainties are calculated from deviations in
calculating the density. Experimental results from this process are then used to calibrate the
simulation to determine the number of simulation timesteps which correspond to a minute of
physical time. The calibration constant derived is then used to map simulation constants to physical
constants. These constants are later compared to bulk properties.",,,,,,
"['Zhang, Xinchang', 'Pan, Tan', 'Li, Wei', 'Liou, Frank']",2021-11-11T15:29:01Z,2021-11-11T15:29:01Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90220', 'http://dx.doi.org/10.26153/tsw/17141']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['direct metal deposition', 'repair', 'co-based alloy', 'tool steel']",Experimental Characterization of a Direct Metal Deposited Cobalt-Based Alloy on Tool Steel for Component Repair,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13a9aacd-233a-4ab4-bf2b-b49b77148657/download,University of Texas at Austin,"Die casting dies made of tool steel is subject to impact, abrasion and cyclic thermo-mechanical loading that delivers damage such as wear, corrosion, and cracking. To repair such
defects, materials enveloping the damage need to be machined and refilled. In this study, V-shape
defects with varied sidewall inclination angles were prepared on H13 tool steel substrates and
refilled with cobalt-based alloy using direct metal deposition (DMD) for superior hardness and
wear resistance. The microstructure of rebuild samples was characterized using an optical
microscope (OM) and scanning electron microscope (SEM). Elemental distribution from the
substrate to deposits was analyzed using energy dispersive spectrometry (EDS). Mechanical
properties of repaired samples were evaluated by tensile test and microhardness measurement.
Fracture mechanism in tensile testing was analyzed by observing the fracture surface. The
experiment reveals that V-shape defects with sidewall beyond certain angles can be successfully
remanufactured. The deposits were fully dense and free of defects. The microstructure and tensile
test confirm the solid bonding along the interface. The tensile test shows the mean ultimate tensile
strength (UTS) of repaired samples is approximated 620 MPa, where samples fractured at the
deposits region. Hardness measurement reveals the hardness of deposits is around 810 HV which
is much higher than that of the substrate.",,,,,,
"['Meachum, J. Mark', ""O'Rourke, Amanda"", 'Yang, Yong', 'Fedorov, Andrei G.', 'Degertekin, F. Levent', 'Rosen, David W.']",2021-09-29T20:30:54Z,2021-09-29T20:30:54Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88216', 'http://dx.doi.org/10.26153/tsw/15157']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing via Microarray Deposition', 'printed fluids', 'high-viscosity production materials', 'piezoelectrically-driven ultrasonic printhead', 'droplet ejection quality']",Experimental Characterization of High Viscosity Droplet Ejection,Conference paper,https://repositories.lib.utexas.edu//bitstreams/488e7044-9c9d-432a-b1d8-a3d080948549/download,University of Texas at Austin,"Additive Manufacturing via Microarray Deposition (AMMD) expands the allowable range of
physical properties of printed fluids to include important, high-viscosity production materials
(e.g., polyurethane resins). This technique relies on a piezoelectrically-driven ultrasonic printhead that generates continuous streams of droplets from 45 mm orifices while operating in the
0.5 to 3.0 MHz frequency range. Unique to this new printing technique are the high frequency of
operation, use of fluid cavity resonances to assist ejection and acoustic wave focusing to generate
the pressure gradient required to form and eject droplets. Specifically, we found that peaks in the
ejection quality corresponded to predicted device resonances. Our results indicate that the
micromachined ultrasonic print-head is able to print fluids up to 3000 mN-s/m2, far above the
typical printable range.",,,,,,
"['Álvarez-Trejo, A.', 'Cuan-Urquizo, E.', 'Roman-Flores, A.']",2024-03-27T15:35:18Z,2024-03-27T15:35:18Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124482', 'https://doi.org/10.26153/tsw/51090']",en,2022 International Solid Freeform Fabrication Symposium,Open,"['lattice beams', 'Bezier curve', 'fused filament fabrication', 'additive manufacturing', '3D printing']",EXPERIMENTAL CHARACTERIZATION OF THE MECHANICAL PROPERTIES OF 3D PRINTED BÉZIER-BASED LATTICE BEAMS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0c0b73a9-1a86-4baf-8ce2-756386e1fb24/download,University of Texas at Austin,"Architected materials are widely used in additive manufacturing to reduce weight. The
controlled arrangement of material allows to tailor their mechanical properties by tuning their
geometrical parameters. A parametrization based on cubic Bézier curves is employed here to
generate lattice beams by changing the position of a free control point. Two topologies with the
same volume fraction and base curve for the lattice constituent elements at different positions are
studied and compared. Lattice beams are manufactured via Fused Filament Fabrication of
polylactic acid. The effective stiffness and yield stress of these lattice beams is analyzed
experimentally using three-point bending tests. Adjusting the control point location leads to
tailoring the effective mechanical properties of the lattice beams. This methodology leads to the
synthesis of architected topologies with customized mechanical properties.",,,,,,
"['Obielodan, J.O.', 'Janaki Ram, G.D.', 'Stucker, B.E.']",2021-09-23T21:42:25Z,2021-09-23T21:42:25Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88028', 'http://dx.doi.org/10.26153/tsw/14969']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic consolidation', 'foil joints', 'defect free structural members']",An Experimental Determination of Optimum Foil Joint Conditions for Structural Parts Fabricated by Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66bc9591-94d2-45d1-bcc8-0c3a1bff58cf/download,,"This paper describes an investigation of the optimum conditions necessary to eliminate defects at 
foil joints in parts fabricated by ultrasonic consolidation. Tensile test specimens were fabricated 
with different foil joint conditions of varying degrees of overlap in the deposition layers. They 
were subjected to tensile tests to determine their mechanical properties. Microstructures of 
samples were also studied. Experimental results show correlations between foil joint condition 
and mechanical strength. Sample microstructures also show correlations between the bonding 
qualities of the foil joints and the strengths obtained. The study highlights an important process 
parameter to control for fabrication of defect free structural members by ultrasonic consolidation.",,,,,,
"['Gonzalez, R.', 'Stucker, B.']",2021-09-28T19:12:20Z,2021-09-28T19:12:20Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88157', 'http://dx.doi.org/10.26153/tsw/15098']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic consolidation', 'Stainless Steel structures', 'parameter optimization', 'Stainless Steel 316L annealed']",Experimental Determination of Optimum Parameters for Stainless Steel 316L Annealed Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0ed9401-f047-4d64-ba56-ccf442e96c2a/download,University of Texas at Austin,"Ultrasonic consolidation is being investigated for building Stainless Steel structures. In this
study, parameter optimization for ultrasonic consolidation of Stainless Steel 316L annealed is
assessed by evaluating experimental factors of oscillation amplitude, welding speed, normal
force and temperature. An L-16 Taguchi design was used to establish the statistical significance
of these factors and identify the combination of processing parameters that maximizes linear
welding density. Optical microscopy was performed to investigate bond quality.",,,,,,
"['Ye, Junyang', 'Babazadeh-Naseri, Ata', 'Fregly, Benjamin J.', 'Higgs III, C. Fred']",2024-03-27T15:37:19Z,2024-03-27T15:37:19Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124483', 'https://doi.org/10.26153/tsw/51091']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['hierarchical lattices', 'manufacturing defects', 'digital image correlation', 'experimental', 'functional graded lattice', 'micro-CT', 'Ti-6Al-4V']",EXPERIMENTAL EVALUATION OF HIERARCHICAL FUNCTIONALLY GRADED LATTICES USING DIGITAL IMAGE CORRELATION AND MICRO-CT,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13a71709-5b7d-46a0-aea8-88ca243f9a1a/download,University of Texas at Austin,"Hierarchical meta-materials based on functionally-graded lattices (FGLs) have the benefit of customizable
material properties. However, the effects of sharp transitions on the effective properties of FGLs have yet to be
evaluated. This experimental study focused on characterizing the compressive properties of hierarchical FGLs
built with smooth or sharp gradings. A total of 12 samples were 3D-printed in Ti-6Al-4V alloy and tested in axial
compressive loading. Digital image correlation (DIC) was used to measure displacements and deformations. The
3D-printing quality of FGLs was also evaluated by micro-CT imaging of 5 samples. The results showed that the
cross-sectional areas of struts in FGLs with sharp transitions were 26% smaller than uniform lattices and FGLs
with smooth transitions. Compression testing also confirmed a lower average elastic modulus in FGLs with sharp
gradings. These results will provide insights for incorporating adjustment factors to account for the loss of strength
in FGLs.",,,,,,
"['Goel, Abhishek', 'Bourell, David']",2021-09-30T13:26:06Z,2021-09-30T13:26:06Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88233', 'http://dx.doi.org/10.26153/tsw/15174']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['room temperature infiltration', 'Selective Laser Sintering', 'electrochemical infiltration', 'metallic matrix composites']",Experimental feasibility of Electrochemical Infiltration of Laser Sintered Preforms,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1283db39-2301-453d-8786-e8af106a0bdd/download,University of Texas at Austin,"This research deals with the experimental feasibility of room temperature infiltration of Selective
Laser Sintered preforms with metals. The existing principles of electrochemical deposition
techniques were adapted and modified for carrying out the infiltration at low temperatures.
Electroless and electrolytic deposition processes were adapted and modified to carry out metal
ion infiltration and deposition within interconnected pores. The electrolytic infiltration process
was modified by inserting a conductive graphite cathode in the center to draw the positive nickel
ions through the interconnected porous network and to deposit them on the pore walls. Forced
diffusion method was also attempted by forcing the electrolyte through the preform at high
pressures. One of the major benefits of electrochemical infiltration is low processing
temperature. Low temperature reduces both energy consumption and associated carbon-footprint
and also minimizes undesirable structural changes. Both conductive and non-conductive
preforms may be electrochemically infiltrated, and MMCs produced by this method have
potential for use in structural applications. This research is sponsored by the National Science
Foundation, Grant CMMI-0926316.",,,,,,
"['Zhao, Xiayun', 'Wang, Jenny M.', 'Zhao, Changxuan', 'Jariwala, Amit', 'Rosen, David W.']",2021-10-28T19:56:11Z,2021-10-28T19:56:11Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89685,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['exposure controlled projection lithography', 'interferometric curing monitoring and measurement', 'ECPL', 'ICM&M', 'in-situ', 'process accuracy']",Experimental Implementation and Investigation of Real-Time Metrology for Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1010dc0b-d443-4bfa-b144-051d245abbbf/download,University of Texas at Austin,"Exposure Controlled Projection Lithography (ECPL) is a stereolithography based process,
curing photopolymer parts on a stationary substrate. To improve the process accuracy with
closed-loop control, an in-situ interferometric curing monitoring and measurement (ICM&M)
system was developed to infer the output of cured height. The previously reported ICM&M
method incorporated a sensor model and online parameter estimation algorithms based on
instantaneous frequency. In this paper, to validate the ICM&M method, an application program
was created in MATLAB to integrate the ECPL and ICM&M systems and to acquire and analyze
interferograms online. Given the limited computing power, the interferogram analysis is
performed offline. Experiments were performed curing square samples by varying exposure time
and intensity. They show that the ICM&M can provide a cost-effective metrology for cured
heights with excellent accuracy and reliability, and decent capability of estimating lateral
dimensions. The offline ICM&M is a convincing demonstration and benchmark for the real-time
ICM&M metrology.",,,,,,
"['Iyibilgin, Osman', 'Yigit, Cemil']",2021-10-12T18:13:41Z,2021-10-12T18:13:41Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88711', 'http://dx.doi.org/10.26153/tsw/15645']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['cellular lattice structures', 'Fused Deposition Modeling', 'compressive properties', 'unit cells']",Experimental Investigation of Different Cellular Lattice Structures Manufactured by Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/00d32033-c5b4-4167-b86b-33a19f9eff52/download,University of Texas at Austin,"Experimental tests were conducted to evaluate the compressive properties (yield strength and
compressive modulus) and build time for five different cellular lattice structures fabricated by the
Fused Deposition Modeling (FDM) process. The lattice structures had repeating unit cells, and
the shapes of the unit cell under study included honeycomb, square, diamond, triangle, and
circle. Test specimens were manufactured by a Stratasys Fortus 400mc machine using ABS
(Acrylonitrile Butadiene Styrene) as the part material. The five different lattice structures were
compared with each other and also with the sparse and sparse-double dense build styles that are
directly available from the Fortus machine. Honeycomb structure was found to have the best
compression properties for the same porosity, although the differences among the different
lattice structures were small (<7%). All of these lattice structures were found to have much
higher strength than the specimens with the same porosity built using the sparse and sparse-double dense styles. However, the various lattice structures required significantly longer build
times than the sparse and sparse-double dense builds. For the honeycomb structure, our
investigation also included the effects of porosity and cell size. Higher porosity led to lower
compression strength but shorted build time. For the same porosity, the yield strength could be
increased and the build time shortened simultaneously by having a certain cell size.",,,,,,
"['Zhao, Xiyue', 'Mason, Michael S.', 'Huang, Tieshu', 'Leu, Ming C.', 'Landers, Robert G.', 'Hilmas, Gregory E.', 'Easley, Samuel J.', 'Hayes, Michael W.']",2020-03-09T14:11:17Z,2020-03-09T14:11:17Z,9/4/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80181', 'http://dx.doi.org/10.26153/tsw/7200']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Freeze-form Extrusion Fabrication,Experimental Investigation of Effect of Environment Temperature on Freeze-form Extrusion Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97b15405-0eb9-48d8-b63a-808e4cdd512e/download,,,,,,,,
"['Wagner, Joshua J.', 'Shu, Hang', 'Kilambi, Rahul', 'Higgs, C. Fred III']",2021-11-16T16:02:13Z,2021-11-16T16:02:13Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90325', 'http://dx.doi.org/10.26153/tsw/17246']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['fluid dynamic', 'particle dynamic', 'droplet impact', 'powder bed', 'binder jet 3D printing']",Experimental Investigation of Fluid-Particle Interaction in Binder Jet 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9922c8d-582a-4c78-94e1-d48dc19395b9/download,University of Texas at Austin,"Wide-scale adoption of binder jet 3D printing for mission-critical components in
aerospace, biomedical, defense, and energy applications requires improvement in mechanical
properties and performance characteristics of end-use components. Increased fidelity may be
achieved with better understanding of the interfacial physics and complex fluid-particle
interactions fundamental to the process. In this work, an experimental testing apparatus and
procedure is developed to investigate the fluid and particle dynamics occurring upon impact of
jetted binder droplets onto a powder bed. High-speed, microscopic imaging is employed to capture
short time-scale phenomena such as ballistic particle ejection, capillary flow, and particle
clustering. The effects of different process parameters (e.g., translational printhead velocity, jetting
frequency, and impact velocity) on the dynamics of Inconel powder are studied. These experiments
reveal that the fluid-particle interaction is significantly affected by a combination of printing
parameters, ultimately governing the quality and performance of binder jet 3D printed
components.",,,,,,
"['Kadekar, Vinay', 'Prakash, Sashikanth', 'Liou, Frank']",2020-02-12T16:10:07Z,2020-02-12T16:10:07Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79945', 'http://dx.doi.org/10.26153/tsw/6971']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Laser Metal Deposition,Experimental Investigation of Laser Metal Deposition of Functionally Graded Copper and Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1fbc743d-2ce5-4e3b-af01-bcb200d86072/download,,"Laser metal deposition is an emerging technology for producing fully dense
metallic parts. This process shows a promising future for the deposition of functionally
graded steel - copper alloys. Good thermal conductivity of copper and a high wear
resistance of steel can be achieved in dies and cores. However, to accomplish this, there
are many issues to be resolved, such as the formation of an undesirable phase,
solidification cracking, porosity at the interface and difference in thermal coefficient of
expansion between steel and copper. The influences of process variables, such as laser
power, laser scan speed, composition, powder flow rate, on the success of the process,
should be studied.",,,,,,
"['Kruth, Jean-Pierre', 'Deckers, Jan', 'Yasa, Evren']",2020-03-11T15:40:48Z,2020-03-11T15:40:48Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80256', 'http://dx.doi.org/10.26153/tsw/7275']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,Experimental Investigation of Laser Surface Remelting for the Improvement of Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e85e10b2-116d-407d-9be4-e099cea43bf2/download,,,,,,,,
"['Kao, Yi-Tang', 'Dressen, Trace', 'Kim, Dong Sung']",2021-10-21T15:05:12Z,2021-10-21T15:05:12Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89388,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'additive manufacturing', 'composite materials']",Experimental Investigation of Mechanical Properties of 3D-Printing Built Composite Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/afa10a57-fc20-446a-b2cc-2b5028d4f952/download,University of Texas at Austin,"This paper studies the mechanical behaviors of a new composite material manufactured by
3D printing and polymer impregnation techniques. This composite uses 3D-printed plaster with an
open-cellular structure as a frame to encapsulate the silicone resin (PDMS) to form a solid body.
Because of the vastly different characteristics of the materials that make it up, the composite could
have a wide variety of mechanical behaviors. In this study, design of experiment was performed
with four-point bending tests using different composition ratios and sizes of open cells to
determine the mechanical properties of the composite. These properties include maximum flexural
stress (σmax), flexural secant modulus of elasticity (Ef), and toughness indices (I5 and I20). The
experimental results show that both Ef and σmax are proportional to the plaster content and the unit
cell size, while I20 had an opposite trend. The Ef ranged from 20 to 280 MPa, and σmax ranged from
0.3 to 1.2 MPa for a 25%-75% plaster content and 3.25-6.5 mm cell size. Statistical analysis further
confirmed the differences between these cases. This paper has demonstrated the capability of this
composite to exert different mechanical properties for functional applications.",,,,,,
"['Ravi Kumar, Y.', 'Manmadhachary, A.', 'Krishnanand, L.']",2021-10-18T20:45:09Z,2021-10-18T20:45:09Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89239,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['CT', 'dimensional error', 'volumetric error', 'rapid prototyping', 'CT image acquisition', 'ANOVA']",Experimental Investigation of Process Parameters on 64 Slice Spiral CT Scanner of Medical Models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13f28a33-421e-4026-9232-652520335b89/download,University of Texas at Austin,"Rapid Prototyping (RP) is one of the advanced manufacturing methods to develop
medical models. These models are generated by 3-Dimensional (3D) Computer Aided Design
(CAD) model using Computed Tomography (CT) images. One of the advanced CT scanners to
capture the large volume of tissues in shorter scan time is 64 slice spiral CT scanner. While
developing these medical models, dimensional and volumetric errors occur due to Beam
Hardening (BH) effect. This work has led to explore the influence of various CT Image
acquisition parameters on the dimensional and volumetric errors, which are evaluated
experimentally. A L9 orthogonal array and signal to noise ratio are applied to study performance
characteristics of CT image acquisition parameters like tube voltage, tube current and pitch. The
experimental results are analyzed by using the analysis of variance (ANOVA) method and
significant factors are identified. In this work, it has been concluded that there is a reduction of
dimensional error from 1.43 mm to 0.52 mm and volumetric error from 6793 mm3 to 3892 mm3.",,,,,,
"['Czink, S.', 'Schulze, V.', 'Dietrich, S.']",2024-03-25T23:51:51Z,2024-03-25T23:51:51Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124345', 'https://doi.org/10.26153/tsw/50953']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PBF-LB', 'AlSi10Mg', 'additive manufacturing']",EXPERIMENTAL INVESTIGATIONS OF INHOMOGENEOUS COMPONENT PROPERTIES IN LASER-BASED ADDITIVE MANUFACTURING OF AlSi10Mg,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6609f58c-d7db-465a-a502-419f1ab97109/download,University of Texas at Austin,"In the laser-based additive manufacturing (PBF-LB) process of AlSi10Mg components, the
layer-by-layer deposition leads to microscopic and macroscopic thermal effects (shrinkage,
residual stresses, overheating) depending on the component geometry. This results in a strong
dependence of the microstructure and therefore of the process-induced material properties on the
shape of the manufactured component. To analyze this behavior, components with different
geometric aspects, such as various construction angles, were built using the PBF-LB process. In
order to perform a spatially-resolved characterization and evaluation of the mechanical behavior
of the component, small-scale tensile specimens in the sub-millimeter range were manufactured
from representative areas of the components. With the obtained results, design approaches based
on local material data can be improved significantly.",,,,,,
"Liu, Jie",2021-09-30T15:43:00Z,2021-09-30T15:43:00Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88267', 'http://dx.doi.org/10.26153/tsw/15208']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'iron based alloy', 'nano-Al2O3 ceramic bulk materials']",Experimental Research on Fabrication of Iron Based Alloy and Nano-Al2O3 Powder Parts by Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7d89907c-0e99-43d6-b8a0-362252b476c0/download,University of Texas at Austin,"Experiments on selective laser sintering of Iron Based Alloy and nano-Al2O3 Ceramic Bulk
Materials are carried out and effect of sintering parameters on the process is analyzed
systematically. A reasonable selective laser sintering technique which can be used to fabricate
parts wit h free shape is obtained and verified wit h a multilayer sintering experiment. The
component and t he microstructure of t he sintering production is tested. The influences of
parameters and the amount of nano-Al2O3 on microstructure and microhardness of the sintering
parts are studied. Laser sintering iron-based alloy experiments show that: microhardness has
been noticeably improved. It is indicated that with the selective laser sintering technique
obtained above, nano-alumina can be processed to manufacture three-dimension parts with free
shape. With the addition of Al2O3 and the increase of composite parts of the grain gradually
thinning, microhardness gradually improved nanocomposite parts for the microstructure of the
dendrite skeleton-shaped crystal and the plane together, the internal Al2O3 dispersion
organizations to strengthen the implicit crystal martensite and ferrite mixed organizations.",,,,,,
"['Sager, Benay', 'Rosen, David W.', 'Shilling, Meghan', 'Kurfess, Thomas R.']",2019-11-15T16:18:05Z,2019-11-15T16:18:05Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78420', 'http://dx.doi.org/10.26153/tsw/5507']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Stererolithography,Experimental Studies in Stereolithography Resolution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5af4e4b0-a42d-4e31-a88f-a584fc64dbc0/download,,"As we move towards micron-scale rapid manufacturing, it is critical to understand build
resolution of Stereolithography technology. In order to determine the resolution limitations,
positive and negative features on Stereolithography parts were built and analyzed. Results from
several experiments were compared to an analytical model and important resolution issues are
highlighted. Based on these experimental results, parameters that will maximize build resolution
for a number of well-understood shapes are suggested in the paper. Build resolution experimental
results, analysis, and measurement techniques are discussed. Conclusions are drawn related to
feature shape as resolution limits are approached.","We gratefully acknowledge the support from the RPMI member companies and the George
W. Woodruff School of Mechanical Engineering at Georgia Tech. This work was partially
funded by the National Science Foundation under Grant Number DMI-9988664.",,,,,
"['Paul, Sumit', 'Yang, Li']",2023-03-01T17:27:29Z,2023-03-01T17:27:29Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117552', 'http://dx.doi.org/10.26153/tsw/44432']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,An Experimental Study of Cellular Mechanical Interface in a Bi-Material Structure Fabricated by Material Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03801607-228a-4de6-8a84-0707e2fcf1ba/download,,"This work is a continuation of the preliminary project with the investigation of the characteristics 
of the cellular structure-based mechanical interlocking interface designs for bi-material structures 
fabricated by material extrusion additive manufacturing (AM). Three different cellular designs, 
including auxetic, body centered cubic (BCC), and octahedral, were investigated for the topology 
design effects on the interface performance. In addition, the effects of build orientation and 
interface polarity were also studied. The results clearly suggested that the cellular-based 
mechanical interlocking interface exhibit significantly enhanced ductility and energy absorption 
that can be desirable to many applications, and that the interface characteristics are influenced by 
both the topology design of the cellular structures and the intrinsic properties of the processed 
materials.",,,,,,
"['Zhang, Shanshan', 'Miyanaji, Hadi', 'Yang, Li', 'Zandinejad, Amir Ali', 'Dilip, J.J.S.', 'Stucker, Brent']",2021-10-18T20:52:25Z,2021-10-18T20:52:25Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89242,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'dental porcelain', 'dental restorations']",An Experimental Study of Ceramic Dental Porcelain Materials Using a 3D Print (3DP) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90360de4-d948-4290-b346-c1b1223063ff/download,University of Texas at Austin,"Dental porcelain materials have been used widely in dental restorations such as crowns,
veneers and onlays. In this study, a commercial dental-grade porcelain powder (IPS InLine Dentin)
was investigated for compatibility with 3D printing. An extensive experimental study was carried
out to evaluate the effects of various in-process and post-process parameters on the geometrical
accuracies and porosities of the dental porcelain structures, and optimal process parameters were
determined that result in homogeneous shrinkage and minimized part distortions. This study
established a practical guideline for the direct fabrication of dental porcelain structures, which
enabled further development of this material that focused on performance improvement.",,,,,,
"['Ramirez Chavez, Irving E.', 'Noe, Cameron', 'Sekar, Vigneshwaran', 'Jogani, Shainil', 'Israni, Siddharth', 'Bhate, Dhruv']",2021-11-30T19:47:37Z,2021-11-30T19:47:37Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90526', 'http://dx.doi.org/10.26153/tsw/17445']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['design for additive manufacturing', 'stiffener', 'compression', 'plate', 'shell', 'topology optimization']",An Experimental Study of Design Strategies for Stiffening Thin Plates under Compression,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ccd6943-2acb-4dfb-91e0-328e6d18b65e/download,University of Texas at Austin,"Increasing stiffness and failure loads while minimizing mass is useful in many engineering
applications, including the design of thin plates and shells. In this paper, the performance of thin
plates using a range of stiffening approaches were studied for the specific instance of compressive
loading. Periodic, graded, stepped, “Voronoi” stochastic, and topologically optimized patterns
were explored. These stiffening designs were realized using different software tools and
manufactured with the Selective Laser Sintering (SLS) process. These 3D printed specimens were
tested under compression to assess their mechanical response. Videos of these tests were recorded
to study the shape of the failure modes. This data was analyzed to determine the performance of
the different stiffener designs, in comparison to the performance of baseline plates without any
stiffening. The study concludes with a discussion of the results and their implications for stiffening
thin plates, showing that triangular and stochastic stiffening strategies show particular promise in
increasing specific compressive stiffness and specific buckling load.",,,,,,
"['Guo, Nannan', 'Leu, Ming C.']",2021-10-05T18:48:46Z,2021-10-05T18:48:46Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88405', 'http://dx.doi.org/10.26153/tsw/15344']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'Polymer Electrolyte Membrane', 'fuel cells', 'graphite composite bipolar plates', 'flow fields']",Experimental Study of Polymer Electrolyte Membrane Fuel Cells using a Graphite Composite Bipolar Plate Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9e76ed2-13f6-41b9-94b2-bfab0c2b6652/download,University of Texas at Austin,"Selective Laser Sintering (SLS) can be used to fabricate graphite composite bipolar plates
with complex flow fields for Polymer Electrolyte Membrane (PEM) fuel cells. The additive
manufacturing process can significantly reduce the time and cost associated with the research
and development of bipolar plates as compared to other fabrication methods such as compression
molding. In this study, bipolar plates with three different designs, i.e., parallel in series,
interdigitated, and bio-inspired, were fabricated using the SLS process. The performance of these
SLS-fabricated bipolar plates was studied experimentally within a fuel cell assembly under
various operating conditions. The effect of temperature, relative humidity, and pressure on fuel
cell performance was investigated. In the tests conducted for this study, the best fuel cell
performance was achieved with a temperature of 75℃, relative humidity of 100%, and back
pressure of 2 atm.",,,,,,
"['Rajan, Jagan R.', 'Wood, Kristin L.', 'Malkovich, Nick']",2019-10-18T14:45:21Z,2019-10-18T14:45:21Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76227', 'http://dx.doi.org/10.26153/tsw/3316']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sintering,Experimental Study of Selective Laser Sintering of Parmax,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03938250-f7c0-4629-9872-c090dffeb04c/download,,"Selective Laser Sintering (SLS) has been used to successfully process crystalline
polymers, ceramics and metals. However, wide range of materials available and their
applications have acted as an impetus to expand the applications of SLS to different material
systems. This paper presents one such experimental study undertaken to explore the application
of SLS to process Parmax® polymers – a family of high performance amorphous poly pphenylenes. As a part of the collaborative study, various process parameters and material
formulations were tried out to ascertain the feasibility of the process and the initial results
obtained look promising. This paper lists the material formulations tested and process parameters
controlled. Also, analysis of the results of the experimental study and the outline of the next
phase of research to be undertaken have been described. This study was motivated by the
numerous applications of Parmax® in the electronics, defense and aerospace industries as well as
the goal to expand the applications and utility of SLS.",,,,,,
"['Torossian, Kevin', 'Bourell, David']",2021-10-21T22:09:04Z,2021-10-21T22:09:04Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89458,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['snap-fits', 'additive manufacturing', 'mating force', 'dismounting force', 'geometrical parameters']",Experimental Study of Snap-Fits Using Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a2b5f40-e657-4b34-86ba-17070c3cadbf/download,University of Texas at Austin,"A snap-fit is a mechanical joint system whose mating parts exert a cam action, flexing until one
part slips past a raised lip on the other part, preventing their separation. The use of snaps in
additive manufacturing (AM) is an approach for assembling components of parts too large to
build in one piece in AM. There are broadly two types of snap-fits possible to encounter,
permanent and non-permanent, depending on the design geometry. An experimental study
was carried out to evaluate the mating/dismounting force for snap-fits regarding several
geometrical parameters for additive manufacturing. The design chosen for this study has been
established from the start to work on only one design. The parameters chosen for experimental
investigation were the mating angle, the separation angle and the inner diameter of the mating
part. All in all, fifteen pairs were designed and additive manufactured for evaluation. The force
required to insert and separate the snap components was recorded and compared to the value
based on a derived equation.",,,,,,
"['Sun, Q.', 'Rizvi, G.M.', 'Bellehumeur, C.T.', 'Gu, P.']",2019-11-20T16:46:17Z,2019-11-20T16:46:17Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78481', 'http://dx.doi.org/10.26153/tsw/5566']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Polymer Filaments,Experimental Study of the Cooling Characteristics of Polymer Filaments in FDM and Impact on the Mesostructures and Properties of Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69809e49-4f1c-4520-8bbb-1f311c043ee5/download,,"The bonding quality among polymer filaments in the fused deposition modeling (FDM)
process determines the integrity and mechanical properties of the resultant prototypes. This
research investigates the bond formation among extruded acrylonitrile butadiene styrene (ABS)
filaments in the FDM process. Experimental measurements of the temperature profiles were
carried out for different specimens and their effects on mesostructures and mechanical properties
were observed. Models describing the formation of bonds among polymer filaments during the
FDM process are discussed. Predictions of the degree of bonding achieved during the filament
deposition process were made based on thermal analysis of extruded polymer filaments. The
bond quality was assessed based on the growth of the neck formed between adjacent filaments
and their failure under flexural loading. Further experimental work is underway to assess the
validity of the proposed models.","The financial support for this work was provided by the Natural Sciences and
Engineering Research Council of Canada (NSERC) through Research Grants awarded to Drs.
Bellehumeur and Gu.",,,,,
"['Horton, Leslie', 'Gargiulo, Edward']",2018-05-03T18:39:02Z,2018-05-03T18:39:02Z,1993,Mechanical Engineering,doi:10.15781/T2K35MX4R,http://hdl.handle.net/2152/65056,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'rapid prototyping', 'TRIHATCH']",An Experimental Study of the Parameters Affecting Curl in Parts Created Using Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d8c6706e-ebf0-4d35-9225-8f89e637b96b/download,,,,,,,,
"['Lakshminarayan, Uday', 'Marcus, H.L.']",2018-04-19T16:01:43Z,2018-04-19T16:01:43Z,1992,Mechanical Engineering,doi:10.15781/T27H1F42X,http://hdl.handle.net/2152/64376,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'CAD', 'laser sintering', 'SLS']",An Experimental Study of the Relationship between Microstructure and Mechanical Properties of a Ceramic Composite Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/60800070-ce6f-4520-af76-ea8a83c1bfdf/download,,"Alumina-ammonium phosphate powder blends were processed with
Selective Laser Sintering. Ammoniumphosphate with a melting point of 190°C, acts as a
binder when processed with a laser and holds the alumina (m.p. 2300°C) particles
together to form a ""green"" body. When the green body is heat treated at 850°C for 6
hours, ammonium phosphate decomposes evolving ammonia and water vapor. Residual
P205 reacts with alumina to form aluminum phosphate. This results in a composite of
unreacted alumina with a coating of aluminum phosphate around the alumina particles.
The variation of compressive strength of these low density ceramic composites was
investigated in terms of the particle size distribution the amount of binder in the initial
blend. It was observed that the strength depends on the relative density and initial blend
composition and the critical flaw size. A constitutive equation was formulated to
characterize the influence of the relative density, binder composition and the critical flaw
size on the strength of the composite.",,,,,,
"['Valenti, Justin D.', 'Bartolai, Joseph', 'Yukish, Michael A.']",2023-02-09T18:58:38Z,2023-02-09T18:58:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117441', 'http://dx.doi.org/10.26153/tsw/44322']",eng,2022 International Solid Freeform Fabrication Symposium,Open,wing structure,Experimental Study of Wing Structure Geometry to Mitigate Process-Induced Deformation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19a52146-2128-45d8-8fa5-937a0aff8ff5/download,,"Small uncrewed aerial vehicles that are fabricated with material extrusion additive manu-
facturing often have wings that are single-perimeter structures with sparse internal structure.
The large distance between internal supports creates an “unsupported-wall distance”, which
leaves the wing skin prone to deformation during fabrication. This work explores and quan-
tifies the relationship between the deformation of the wing skin and three geometric param-
eters: (1) unsupported-wall distance, (2) local surface curvature, and (3) extrusion width. A
three-level full factorial study was devised in which wing sections of varying surface curva-
ture, unsupported-wall distance, and extrusion width were fabricated with polymer material
extrusion additive manufacturing. The surfaces of the wing sections were then digitized into
point clouds with a coordinate measuring machine, and the point cloud data were directly
compared to the GCode used to print each wing section. The deformation data was analyzed
to quantify the relationship between deformation and the experimental parameters. From
the experiment, a non-dimensional term was identified that captures a bounding relationship
between the geometric parameters and the deformation. Finally, a mathematical expression
was developed to serve an upper bound on unsupported-wall distance based on extrusion
width and surface curvature.",,,,,,
"['Price, Steven', 'Lydon, James', 'Cooper, Ken', 'Chou, Kevin']",2021-10-07T15:55:04Z,2021-10-07T15:55:04Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88488', 'http://dx.doi.org/10.26153/tsw/15422']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['electron beam additive manufacturing', 'powder-based', 'infrared thermal imager', 'temperature measurements']",Experimental Temperature Analysis of Powder-Based Electron Beam Additive  Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb1898dd-ac2c-4021-9973-bf3dd811b9b2/download,University of Texas at Austin,"A near infrared thermal imager has been employed for temperature measurements (build
part surfaces) in the powder-based electron beam additive manufacturing (EBAM) process. A
methodology has also been developed to analyze temperature distributions and history around
the melting scan area. The temperature profiles along the beam scanning clearly show the
moving source of heat phenomenon, with the peak temperature reaching over 2000 °C (for Ti6Al-4V) followed by extremely rapid cooling opposite to the beam scanning direction, except a
slow-cooling portion corresponding to the liquidus-solidus range. The build surface temperatures
and the melt pool sizes, in the localized electron beam scanning area, were studied at various
configurations, e.g., different build heights, also with or without an overhang.",,,,,,
"['Masoomi, M.', 'Thompson, S.M.', 'Shamsaei, N.', 'Elwany, A.', 'Bian, L.']",2021-10-19T18:54:12Z,2021-10-19T18:54:12Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89323,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'powder bed', 'heat transfer', 'stainless steel']",An Experimental-Numerical Investigation of Heat Transfer During Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd7366fe-4a0c-4a73-add8-f92b06658a66/download,University of Texas at Austin,"The heat transfer in and around a part being fabricated via Selective Laser Melting (SLM) is
numerically simulated while considering the surrounding powder bed modeled to have an
effective thermal conductivity. By accurately simulating the powder bed heat transfer during
SLM, mechanical properties of parts can be better predicted. Heat transfer to previously-deposited layers and the build plate are also simulated. In order to validate the presented model,
a thermocouple was embedded into a substrate used and a SLM system was utilized for
performing two experiments. In the first set, various laser power and scan speed combinations
were employed while passing the laser over the thermocouple-embedded substrate. This
procedure calibrated the numerical model and demonstrated that the heat transfer due to
convection and radiation during deposition of a single layer is approximately 10-15% of initial
laser power input. The final experiment consisted of building a thin wall of SLM of 17-4 PH
stainless steel (SS). The effects of scan pattern and part size on the temperature response of and
around the part are demonstrated as significant. Distinct heating and cooling rates are also
provided for these various cases; indicating the dependency of final microstructure on part size
and the utilized scan pattern.",,,,,,
"['Cormier, Denis', 'Taylor, James', 'Unnanon, Kittnan', 'Kulkarni, Parikshit', 'West, Harvey']",2019-09-23T16:01:45Z,2019-09-23T16:01:45Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75948', 'http://dx.doi.org/10.26153/tsw/3047']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Electro-Photographic,Experiments In Layered Electro-Photographic Printing 267,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9a97942-c581-43ef-afb2-f0f6b03c1114/download,,Electro-photographic printing processes employed by products such as laser printers and photocopiers are commonly used to deposit and fuse thin layers of thermoplastic powder onto paper. This report describes preliminary experiments aimed at adapting the electro-photographic printing process for use as a layered manufacturing technique. 3-D electro-photographic printing holds considerable potential as an inexpensive freeform fabrication technique that is suitable for office environments. The possibilities for selective coloring are also discussed.,,,,,,
"['Hoelzle, David', 'Peng, Hao', 'Ghasri-Khouzani, Morteza', 'Gong, Shan', 'Attardo, Ross', 'Ostiguy, Pierre', 'Aboud Gatrell, Bernice', 'Budzinski, Joseph', 'Tomonto, Charles', 'Neidig, Joel', 'Shankar, M. Ravi', 'Billo, Richard', 'Go, David B.']",2021-11-04T14:00:10Z,2021-11-04T14:00:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89962,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'DMLS', 'optimization', 'build orientation', 'support structure', 'heuristic learning', 'expert survey']",Expert Survey to Understand and Optimize Part Orientation in Direct Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9c41a6b-1779-4657-963c-ab5bc5551a4c/download,University of Texas at Austin,"The additive manufacturing (AM) process Direct Metal Laser Sintering (DMLS) uses a layer-by-layer workflow to build complex architecture metal structures in low-volumes. The primary
process failure mechanism is a thermal stress driven thermal distortion that yields out-of-tolerance
manufacture or complete process failure. However, DMLS design experts have developed
heuristic rules to optimize the part orientation and support structure to reduce the likelihood of
failure. We believe that experts innately attempt to minimize the design metrics of support
volume (V), support-to-part surface area (A), maximal cross-sectional area of the slicing planes
(X), parallelism of part faces with the recoater blade (P), and part height (H); however, it is unclear
what relative weighting of each metric the expert uses. This manuscript details an interactive
expert survey, the statistical analysis of the survey responses, and the synthesis of an automatic
algorithm for part orientation based on survey data. We received responses from 18 experts and
151 total part orientation responses. The median survey respondent had greater than four years
of DMLS experience. Our analysis shows that the expert attempts to minimize metric V the most,
metric X the second most, and metric H the third most; experts put essentially no weight on metrics
A and P. The manuscript concludes with two orientation design studies where the expert survey
responses are used in a least squares minimization algorithm to automatically orient the part for
DMLS manufacture. As a comparison set, novice users were instructed to orient the parts for
best DMLS printing success without using the tool and required multiple attempts to successfully
print the test parts. The automatically oriented parts failed on our first iteration of the code. The
manuscript concludes with our proposed modifications to the code to improve results.",,,,,,
"['Watts, D. M.', 'Hague, R. J.']",2020-03-05T19:47:49Z,2020-03-05T19:47:49Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80149', 'http://dx.doi.org/10.26153/tsw/7170']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Exploiting the Design Freedom of RM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd0bc482-3f86-4789-bc10-cb41ac68c164/download,,"This paper details how Rapid Manufacturing (RM) can overcome the restrictions imposed by the
inherent process limitations of conventional manufacturing techniques and become the enabling
technology in fabricating optimal products. A new design methodology capable of exploiting
RM’s increased design freedom is therefore needed. Inspired by natural world structures of trees
and bones, a multi-objective, genetic algorithm based topology optimisation approach is
presented. This combines multiple unit cell structures and varying volume fractions to create a
heterogeneous part structure which exhibits a uniform stress distribution.",,,,,,
"['Heineman, Jesse J.', 'Lind, Randall F.', 'Chesser, Phillip C.', 'Post, Brian K.', 'Boulger, Alex M.', 'Roschli, Alex', 'Love, Lonnie J.', 'Gaul, Katherine T.']",2021-11-30T19:34:16Z,2021-11-30T19:34:16Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90523', 'http://dx.doi.org/10.26153/tsw/17442']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['SKYBAAM', 'additive manufacturing', 'cable-driven', '3D printing', 'tower structures']",Exploration of a Cable-Driven 3D Printer for Concrete Tower Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/334cfb01-708a-4740-9c56-e5a6fed1ea2a/download,University of Texas at Austin,"Researchers at Oak Ridge National Laboratory’s Manufacturing Research Demonstration
Facility (MDF) are currently developing a cable-driven concrete additive manufacturing (AM)
system called SKYBAAM. This system is a novel solution for 3D printing large structures using
concrete. The current research focuses primarily on proof of concepts for the cable driven
system, material selection, material pumping solutions, and the concrete extruder design.
Looking forward from the success of the current research, this paper investigates the feasibility
of using the SKYBAAM on a larger scale, specifically for extremely tall tower structures. The
current system design presents challenges at a larger scale, and so the primary focus of this paper
is to investigate new designs of a platform that would support large-scale SKYBAAM
operations. Additionally, this paper will discuss the resulting deflections that can be expected
due to machine operation and wind-loading. Excessive structural deflections could lead to loss
of printing accuracy, or even a complete failure of the print, so it is important to establish that
acceptable deflections can be reasonably achieved on these large-scale tower structures.",,,,,,
"['Bai, Yun', 'Williams, Christopher B.']",2021-10-13T21:39:17Z,2021-10-13T21:39:17Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88789', 'http://dx.doi.org/10.26153/tsw/15723']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['high purity copper', 'copper', 'binder jetting', 'additive manufacturing', 'green parts']",An Exploration of Binder Jetting of Copper,Conference paper,https://repositories.lib.utexas.edu//bitstreams/791d58b7-439f-4f7c-8b8c-4c75b272ee22/download,University of Texas at Austin,"The ability to fabricate geometrically complex copper shapes via Additive Manufacturing
(AM) could have a significant impact on the design and performance of thermal management
systems and structural electronics. In this research a Binder Jetting AM process (ExOne R2) was
used to fabricate green parts made of high purity copper powder. Once printed, the green part
was sintered under a reducing atmosphere to create copper parts in pure metal form. The authors
varied (i) powder size, (ii) sintering profiles, and (iii) atmospheric control to explore their effects
on final part density and shrinkage. The sintered part density was 85% of the theoretical value
due to the relatively coarse powder and loose packing of the powder bed. The result
demonstrates the feasibility of using Binder Jetting to create copper parts with complex
geometries.",,,,,,
"['Li, Wei', 'Bouzolin, Dan', 'Nagaraja, Kishore Mysore']",2024-03-26T23:10:22Z,2024-03-26T23:10:22Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124443', 'https://doi.org/10.26153/tsw/51051']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'thermal-fluid model', 'in-space manufacturing', 'reduced gravity', 'space exploration']",EXPLORATORY STUDY OF IN-SPACE WIRE ARC ADDITIVE MANUFACTURING WITH MODELING APPROACH,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e696264-8386-4a42-ab38-73ee120b2479/download,University of Texas at Austin,"Countries all over the world are rushing into space exploration due to crisis of energy and resources
exhaustion on the Earth. Mars is an obvious target because it has a thin atmosphere, good geological similarity,
and is close by in the Solar system. As the satellite of the Earth, Moon is another target since it is very close to
the Earth. For the large spacecrafts such as Mars rovers, periodic maintenance is necessary to ensure the
completion of long-duration exploration missions. In-space wire arc additive manufacturing (WAAM) provides
a potential solution towards sustainable maintenance with onsite repair or additive manufacturing. For in-space
manufacturing, reduced gravity is an important factor. In this work, WAAM processes under reduced gravity
conditions on the Mars and Moon were studied through a multi-physics modeling approach. The metal droplet
transfer, deposition geometry, thermal dissipation, and other key physics in WAAM were simulated. To validate
the modeling approach, an experimental case was conducted on an in-house WAAM platform under the Earth
condition.",,,,,,
"['Roach, M.A.', 'Pennney, J.', 'Jared, B.H.']",2024-03-26T20:49:18Z,2024-03-26T20:49:18Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124406', 'https://doi.org/10.26153/tsw/51014']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['ROS2', 'IOT sensors', 'additive manufacturing']",EXPLORING A SUPERVISORY CONTROL SYSTEM USING ROS2 AND IOT SENSORS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eebab146-eeef-4571-a651-2669ffa3200c/download,University of Texas at Austin,"Whether collecting data from process monitoring sensors or controlling a system of multiple actuators and
electrical systems, a powerful supervisory control system must be developed for additive manufacturing (AM)
systems. The Robot Operating System version 2 (ROS2) is a set of software libraries that can be used to control
robotics systems and has tools for sensor value publishing. This research project is exploring the use of
computational nodes connected to process monitoring sensors and robotic or electrical systems to allow for a
more in-depth knowledge of the system health and process as well as open the possibilities of process control.
These nodes can be connected and controlled by the ROS2 architecture. Work will be discussed exploring the
reliability and speed of common AM processes and sensors such as robot controllers and thermal monitoring.",,,,,,
"['Nabil, S.T.', 'Banuelos, C.', 'Ramirez, B.', 'Cruz, A.', 'Watanabe, K.I.', 'Arrieta, E.', 'Wicker, R.B.', 'Medina, F.']",2024-03-25T23:54:26Z,2024-03-25T23:54:26Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124346', 'https://doi.org/10.26153/tsw/50954']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['E-PBF', 'scanning strategies', 'superalloys', 'Inconel 718']",EXPLORING IN718 ALLOY PRODUCTION WITH BI-DIRECTIONAL RASTER AND STOCHASTIC SPOT MELTING TECHNIQUES USING AN OPEN-SOURCE ELECTRON MELTING SYSTEM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/07b22f79-08d2-4399-b74f-2c5d216250ac/download,University of Texas at Austin,"This study compares the fabrication of IN718 alloy using bi-directional raster and stochastic spot melting
techniques with the open-source FreemeltOne Electron Beam Melting (EBM) system. The research aimed to
produce dense parts using both scanning strategies, employing custom Python code for raster melt beam path
generation and PixelMelt software for stochastic spot melting path generation. After optimizing process
parameters, 10mm height builds for each scanning strategy were fabricated, and their microstructure, hardness,
and density were analyzed using optical microscopy and SEM, Vickers microhardness scale, and a pycnometer.
The findings reveal valuable insights into the effects of scanning strategies on the microstructure, hardness, and
density of IN718 alloy components, advancing additive manufacturing knowledge.",,,,,,
"['Lipman, Robert R.', 'McFarlane, Jeremy S.']",2021-10-19T20:47:46Z,2021-10-19T20:47:46Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89336,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'part geometry', 'tolerances', 'model-based engineering']",Exploring Model-Based Engineering Concepts for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d8bcb02-2da8-4033-a460-ac8e4adad019/download,University of Texas at Austin,"Robust geometry and tolerance representations are needed in additive manufacturing for
precise part specification and interoperability with downstream activities such as manufacturing,
inspection, and long-term archiving. A disconnection exists between process-independent part
geometry and tolerances, and process-dependent information requirements for additive
manufacturing. Existing and emerging standards for part geometry (ASTM AMF, 3MF, ISO
10303 STEP) and tolerances (ASME Y14) contain information related to the additive
manufacturing process. Details of the standards will be discussed, how their use and
improvement can benefit the additive manufacturing process, and their integration into the
model-based engineering paradigm.",,,,,,
"['Gao, Harry', 'Meisel, Nicholas A.']",2021-11-04T14:24:54Z,2021-11-04T14:24:54Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89969,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['conductive filament', 'manufacturability', 'resisitivty', 'material extrusion', 'additive manufacturing']",Exploring the Manufacturability and Resistivity of Conductive Filament Used in Material Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/481db5bf-a3a6-4787-985a-0036e5657a8a/download,University of Texas at Austin,"Additive manufacturing (AM) has the unique ability to build multifunctional parts with
embedded electronics without the need for post-print assembly. However, many existing forms of
multifunctional AM are not easily accessible to hobby-level users. Most hobby-level desktop 3D
printers are only used with non-conductive filaments. Recently however, conductive filaments
have become increasingly available for material extrusion desktop printers. Ideally, the use of these
filaments would allow circuitry to be printed simultaneously with the rest of the structure, enabling
complex, inexpensive, multifunctional structures. However, the resistivity of conductive filament
is significantly impacted by the geometry of the print and the printing parameters used in the build
process. In this study, two types of commercially-available conductive filament were tested under
a variety of parameters. It was found that print temperature, layer height, and orientation all
significantly affect the resistivity in various ways. The knowledge from this research will allow
users to design better multifunctional parts that have reduced resistivity.",,,,,,
"['Li, J.', 'Monaghan, T.', 'Bournias-Varotsis, A.', 'Masurtschak, S.', 'Friel, R.J.', 'Harris, R.A.']",2021-10-18T20:15:06Z,2021-10-18T20:15:06Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89229,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Ultrasonic Additive Manufacturing', 'electronic materials', 'dielectric materials', 'metal matrices']",Exploring the Mechanical Performance and Material Structures of Integrated Electrical Circuits within Solid State Metal Additive Manufacturing Matrices,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9be0905b-a90f-4c75-b53a-ed0bd9e51730/download,University of Texas at Austin,"Ultrasonic Additive Manufacturing (UAM) enables the integration of a wide variety of
components into solid metal matrices due to a high degree of metal plastic flow at low matrix
bulk temperatures. This phenomenon allows the fabrication of previously unobtainable novel
engineered metal matrix components.
The aim of this paper was to investigate the compatibility of electronic materials with
UAM, thus exploring an entirely new realm of multifunctional components by integration of
electrical structures within dense metal components processed in the solid-state. Three different
dielectric materials were successfully embedded into UAM fabricated metal-matrices with,
research derived, optimal processing parameters.
The effect of dielectric material hardness on the final metal matrix mechanical strength
after UAM processing was investigated systematically via mechanical peel testing and
microscopy. The research resulted in a quantification of the role of material hardness on final
UAM sample mechanical performance, which is of great interest for future industrial
applications.",,,,,,
"['Denoual, M.', 'Mognol, P.', 'Lepioufle, B.']",2020-02-13T20:50:16Z,2020-02-13T20:50:16Z,8/25/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79976', 'http://dx.doi.org/10.26153/tsw/7001']",eng,2004 International Solid Freeform Fabrication Symposium,Open,biochips,Exploring Vacuum Casting Techniques for Micron and Submicron Features,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e73ba7dd-9bae-4cc0-a2ba-9ad830dcddaf/download,,"A study of resolution limits in standard rapid prototyping vacuum cast molding processes and
adaptation of this technique to reach submicron accuracy is proposed. Micro-fabrication
technologies are used to fabricate micron and submicron high aspect-ratio patterns on the
original parts. The molding of the original parts is optimized to allow replication of submicron
features. In carefully exploring materials and surface treatments, cast parts are successfully
replicated with submicron and high aspect ratio micron structures. These encouraging results
enable the use of such processes for micro- and nano-systems applications and open the door
to development and production of low cost, high resolution biochips.",,,,,,
"['Bass, Lindsey B.', 'Meisel, Nicholas A.', 'Williams, Christopher B.']",2021-10-21T15:25:30Z,2021-10-21T15:25:30Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89395,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['material jetting', 'multi-material', 'build orientation', 'variability']",Exploring Variability in Material Properties of Multi-Material Jetting Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13ee23e7-31de-4fb6-ad55-698782caa151/download,University of Texas at Austin,"With Additive Manufacturing (AM) capabilities rapidly expanding in industrial applications,
there exists a need to quantify materials' mechanical properties to ensure reliable performance
that is robust to variations in environment and build orientation. While prior research has
examined process-parameter and environmental effects for AM processes such as extrusion, vat
photopolymerization, and powder bed fusion, existing similar research on the material jetting
process is limited. Focusing on polypropylene-like (VeroWhitePlus) and elastomer-like
(TangoBlackPlus) materials, the authors first characterize the anisotropic properties of six
different gradients produced from mixing the two materials in preset quantities. Three build
orientations were used to fabricate parts and analyze tensile stress, modulus of elasticity, and
elongation at break for each material. The authors also present results from an investigation of
how aging of parts in different lighting conditions affects material properties. The results from
these experiments provide an enhanced understanding of the material behaviors relating to
material jetting process parameters and can inform material selection when manufacturing loadbearing parts.",,,,,,
"['Choong, Y.Y.C.', 'Saeed, M.', 'Eng, H.', 'Su, P.-C.', 'Wei, J.']",2021-10-28T22:13:13Z,2021-10-28T22:13:13Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89715,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['shape memory polymers', 'process parameters', '3D printing', 'stereolithography']",Exploring Variability in Shape Memory Properties of Stereolithography Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3750af9-dbe9-4480-80bf-cc898f49e25a/download,University of Texas at Austin,"Shape memory polymers (SMPs) are smart materials that can change shape and revert to
their permanent shape upon external stimulus. Most fabrications of SMPs are based on
conventional methods which limit design freedom, hence additive manufacturing presents an
alternative to expanding more possibilities for applications. In this study, curing process
parameters were optimized for printing of photopolymerized thermoset SMPs by the
stereolithography process. Tert-butyl acrylate (tBA) and di (ethylene glycol) diacrylate (DEGDA)
were copolymerized with variations in crosslinkers to create networks with well-separated
transition temperatures (Tg) that varied in a range from 43.6 to 74.1°C. A fold-deployable shape
memory test was performed and revealed that free-strain recovery and retention deteriorate with
increasing Tg. Nevertheless, the SMPs can undergo at least 20 repeated fold-deploy cycles before
failure. These results are intended to provide better understandings in processing SMPs via
stereolithography, while exploring variability in Tg widens the range of possible applications.",,,,,,
"['Lipton, Jeffrey I.', 'Gluck, Karl', 'Lipson, Hod']",2021-09-30T20:07:46Z,2021-09-30T20:07:46Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88292', 'http://dx.doi.org/10.26153/tsw/15233']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Extensible Digital Fabrication Language', 'XDFL', 'ToolScript', 'system architecture', 'Fab@Home', 'geometric data', 'control processes']",Extensible Digital Fabrication Language for Digital Fabrication Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/29271574-8233-46b1-af30-0183f06fce1e/download,University of Texas at Austin,"While additive manufacturing objects are described by the STL and AMF
standards, the protocol controlling the fabricator is typically machine-specific. In
this paper, we explore a system architecture that converts geometric data into
control processes for equipment. We propose a new Extensible Digital
Fabrication Language (XDFL) and an interpreted ToolScript language that
describes how a geometry is translated into machine commands. An initial
implementation of this system architecture was created and deployed as part of
the Fab@Home project. The introduction of a standard process control language
will decouple process planning from the equipment manufacturer, thereby
catalyzing the introduction of new equipment and development of better process
planners.",,,,,,
"['Rai, Rahul', 'Campbell, Matthew', 'Wood, Kristin']",2020-02-13T21:00:19Z,2020-02-13T21:00:19Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79978', 'http://dx.doi.org/10.26153/tsw/7003']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solid freeform fabrication,Extracting Product Performance by Embedding Sensors in SFF Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ab55e320-c4ca-4908-b81b-995a657d9ed6/download,,"SFF has been instrumental in improving the design process by providing designers with
prototypes that assist them in the communication of design information and design visualization
prior to creating fully functional prototypes. Embedding sensors at key locations within an SFF
part to extract further data and monitor parameters at critical locations not accessible to ordinary
sensors can help immensely in building functional SFF parts. However, this approach requires
data acquisition of information such as temperature and strain values from interiors of products.
In this work, the authors propose new techniques for embedding thermal sensors and strain
gauges into fully dense DuraForm™ during Selective Laser Sintering (SLS) process. The
embedded sensors have been used to measure temperatures and strains. They provide higher
sensitivity, good accuracy, and high temperature capacity.",,,,,,
"['Turner, Irem Y.', 'Wood, Kristin L.', 'Busch-Vishniac, Ilene J.']",2018-11-16T16:16:37Z,2018-11-16T16:16:37Z,1996,Mechanical Engineering,doi:10.15781/T2DZ03M93,http://hdl.handle.net/2152/70293,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['surface quality', 'manufacturing', 'SLS machines']",Extraction of Fault Patterns on SLS Part Surfaces Using the Karhunen-Loeve Transform,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa9e719b-19d2-430b-8f9c-ca0e11ef1fc6/download,,"To gain a thorough understanding of the fault mechanisms in SLS machines, we decompose
SLS profile signals into independent features using a novel tool called Karhunen-Loeve
(KL) transform. These individual features can then be studied separately to monitor the
occurrence of fault patterns on manufactured parts and determine their nature. Analytical
signals with known fault patterns, simulating profile measurement signals from SLS parts,
are used to determine the suitability of the proposed method. Multi-component patterns
are assumed to manifest on SLS part surfaces, resulting from faults in the machine, for
example, the roller mechanism. The results of this work determine the suitability of the KL
transform for condition monitoring and extraction of fault-indicating patterns.",,,,,,
"['Khoshnevis, Behrokh', 'Zhang, Jing']",2021-10-05T18:57:55Z,2021-10-05T18:57:55Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88408', 'http://dx.doi.org/10.26153/tsw/15347']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Contour Crafting', 'sulfur concrete', 'lunar regolith']",Extraterrestrial Construction Using Contour Crafting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/496f36f8-06e8-4468-b8ae-72e0fe9da2e4/download,University of Texas at Austin,"Most proposals for construction of settlements on Moon and Mars are based on
transporting structural elements from Earth and assembling them at the destination. A far less
expensive and potentially practical approach is using Contour Crafting, a large-scale AM
process, in conjunction with in-situ materials. Our trials with sulfur based concrete and sintered
lunar regolith simulant made by NASA show strong promise. Our project ultimately aims at
demonstration of lunar outpost infrastructure construction involving landing pads, blast walls,
roads, shade walls and protective hangars. This paper reports on our very early efforts in the first
stage of the project.",,,,,,
"Zengshe, Liu
Paul, Calvert",2018-11-28T16:28:21Z,2018-11-28T16:28:21Z,1997,Mechanical Engineering,doi:10.15781/T2QZ23331,http://hdl.handle.net/2152/70320,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'control charts', 'SPC']",Extrusion Freeform Fabrication of Bone-Like Mineralized Hydrogels and Muscle-like Actuators,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d14b5cc6-0d1c-4c2a-bff9-d2749e5ed0d0/download,,"Extrusion freeform fabrication has been used to build shapes from agarose, polyacrylamide
and polyacrylic acid hydrogels. Contraction and bending can be induced by pH change or
application ofa voltage between embedded electrodes. Mineral reinforcement can be induced by
incorporating salts into the gels and allowing them to react.",,,,,,
"['Vaidyanathan, R.', 'Lombardi, J.L', 'Walish, J.']",2019-03-13T16:28:28Z,2019-03-13T16:28:28Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73643', 'http://dx.doi.org/10.26153/tsw/785']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['EFF', 'SFF']",Extrusion Freeform Fabrication of Functional Ceramic PrototypeS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/01106edb-2a5c-4020-bb04-50593e9c55ba/download,,"Extrusion Freeforming (EFF) and Fused Deposition Modeling (FDM) processes are established
freeforming techniques capable of fabricating complex shaped ceramic prototypes by the
sequential deposition and solidification of green ceramic feedstock, layer by layer until the final
part results. The freeforming of ceramic parts was accomplished using a commercially available
Stratasys 3D Modeler retrofitted with a high-pressure extrusion head designed by Advanced
Ceramics Research, Inc. (ACR). The manufactured objects had good dimensional tolerances, as
well as real engineering compositions and microstructures. Ceramic feedstock based on two
different silicon nitride powders were developed and successfully used to make prototype parts.
Mechanical properties and microstructural characterization of prototype parts were performed.",,,,,,
"['Lombardi, John L.', 'Calvert, Paul D.']",2018-12-05T20:39:24Z,2018-12-05T20:39:24Z,1997,Mechanical Engineering,doi:10.15781/T2R49GW1M,http://hdl.handle.net/2152/71417,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'EFF']",Extrusion Freeforming of Nylon 6 Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5409b20f-049a-4ceb-af6b-a637b8ea82f0/download,,"Numerous commercial rapid prototyping (RP) processes are capable offabricating
complex shaped components. These processes build prototypes ""from the ground up"" by first
reducing a CAD design ofthe desired prototype to a series ofgeometrical slices followed by the
precise sequential deposition ofraw material layers upon one another. Unfortunately, these RP
processes are limited to producing prototypes from polYmers that exhibit inferior mechanical
properties compared to commercial engineering thermoplastics. Consequently, there are
significant advantages in extending the materials processing capabilities ofRP technology into the
realm ofproducing tough, high strength functional prototypes from engineering polYmers.",,,,,,
"['Calvert, Paul', 'Crockett, Robert', 'Lombardi, John', ""O'Kelly, John"", 'Stuffle, Kevin']",2018-09-26T19:45:15Z,2018-09-26T19:45:15Z,1994,Mechanical Engineering,doi:10.15781/T2XD0RG99,http://hdl.handle.net/2152/68590,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'ACR Systems', 'polymer extrusion']",Extrusion Methods For Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e36d145a-4894-4dab-9fe5-2ba7d2894745/download,,"It is becoming clear that current SFF methods are members of a potentially very large
family. As with current forming methods, it is to be expected that particular materials and
objects will lend themselves best to particular methods. Our group has been working for two
years on extrusion methods of freeform fabrication where a reactive slurry is extruded into a
pattern to form a series of layers that build up a three-dimensional object. A sketch of the
apparatus is shown in figure 1. The slurry may cure chemically either as each layer forms or in
a postcuring oven.
As a member of the SFF family, this method offers great versatility in the range of
materials that can be formed an in control ofthe material structure and composition within a part.
This paper describes our efforts to extend the application of this method from ceramics to
polymer composites, thermoplastics and silica-silica composites.",,,,,,
"['Jin, Y.', 'Plott, J.', 'Shih, A.J.']",2021-10-19T20:09:23Z,2021-10-19T20:09:23Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89329,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['extrusion-based additive manufacturing', 'additive manufacturing', 'moisture-cured silicone elastomer', 'silicone elastomer']",Extrusion-Based Additive Manufacturing of the Moisture-Cured Silicone Elastomer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/55aa485e-1e74-4109-97cb-7cabdb561896/download,University of Texas at Austin,"The extrusion-based additive manufacturing (AM) of moisture-cured silicone elastomer for complex
freeform shape is studied. Due to its low elastic modulus and poor shape retaining ability during the layer-by-layer process, silicone elastomer AM is technically challenging. The experiment for extrusion of room
temperature vulcanization silicone elastomer is conducted to study effects of air pressure, nozzle size and speed, layer height and distance between silicone lines on the flow rate and cross-sectional geometry of silicone
elastomer AM. The COMSOLTM Multiphysics simulation using the level function to track the silicone-air
interface is applied to model the silicone flow. Modeling and experimental results of the diameter and flow rate
of silicone under the free flowing condition has good agreement and shows the potential for model-based
guidelines for AM of silicone elastomers. Effects of the nozzle speed, layer height, and distance between two
adjacent lines are investigated and demonstrate the feasibility and limitations of AM of silicone elastomer.",,,,,,
"['Lipton, Jeffrey I.', 'Cohen, Daniel', 'Heinz, Michael', 'Lobovsky, Maxim', 'Parad, Warren', 'Bernstein, Garrett', 'Li, Tianyou', 'Quartiere, Justin', 'Washington, Kamaal', 'Umaru, Abdul-Aziz', 'Masanoff, Rian', 'Granstein, Justin', 'Whitney, Jordan', 'Lipson, Hod']",2021-09-28T18:31:19Z,2021-09-28T18:31:19Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88149', 'http://dx.doi.org/10.26153/tsw/15090']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Fab@Home', 'business model', 'SFF market']",Fab@Home Model 2: Towards Ubiquitous Personal Fabrication Devices,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c46c014c-fc87-4f0a-9bf1-51c534aae91f/download,University of Texas at Austin,"The open-architecture, open-source Fab@Home platform has proven to be an
important system within the SFF community. In order to facilitate wider spread of
the Fab@Home platform and SFF throughout the world, we aimed to improve
critical aspects of the system, and business model. By changing the electronics
package and streamlining the mechanics, the cost of the system was brought from
$2500 to $1600. By changing the business model we hope to transform the SFF
market and spur innovation.",,,,,,
"['Lipton, Jeffrey', 'MacCurdy, Robert', 'Boban, Matt', 'Chartrain, Nick', 'Withers III, Lawrence', 'Gangjee, Natasha', 'Nagai, Alex', 'Cohen, Jeremy', 'Sobhani, Karina', 'Liu, Jimmy', 'Qudsi, Hana', 'Kaufman, Jonathan', 'Mitra, Sima', 'Garcia, Aldo', 'McNioll, Anthony', 'Lipson, Hod']",2021-10-04T20:42:56Z,2021-10-04T20:42:56Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88343', 'http://dx.doi.org/10.26153/tsw/15282']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'Fab@Home', 'Fab@Home Model 3', 'user base technology', 'cost reduction']","Fab@Home Model 3: A More Robust, Cost Effective and Accessible Open Hardware Fabrication Platform",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9eca8a6-cb13-4557-8e00-438b0cbb4873/download,University of Texas at Austin,"Solid Freeform Fabrication is transitioning from an industrial process and
research endeavor towards a ubiquitous technology in the lives of every designer
and innovator. In order to speed this transition Fab@Home Model 3 was created
with the goal of expanding the user base of SFF technology by lowering the skill
and price barriers to entry while enabling technology developers to leverage their
core competencies more efficiently. The result is a device, which is modular with
respect to tool heads, fabrication processes, and electronics controls, costs under
$1000, and requires only a simple tool set to assemble.",,,,,,
"['Malone, Evan', 'Lipson, Hod']",2020-03-05T19:51:42Z,2020-03-05T19:51:42Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80150', 'http://dx.doi.org/10.26153/tsw/7171']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Solid freeform fabrication,Fab@Home: The Personal Desktop Fabricator Kit,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4391d032-1114-484a-b5b9-37575db243fa/download,,"Solid freeform fabrication has the potential to revolutionize manufacturing, perhaps even
to allow consumers to customize and manufacture goods cost-effectively in their own
home. At present, the florescence of the technology is limited by a “chicken and egg”
paradox. There is insufficient consumer demand and too narrow a range of applications
for SFF systems to allow mass production to reduce their cost and complexity. At the
same time, consumer applications for, demand for, and indeed awareness of SFF
technology is limited by its high cost and complexity. We posit that just as the personal
computer revolution was spurred by development of computer kits, getting SFF
technology into the hands of hobbyists and hackers will simultaneously generate
applications for, and improvements to it. To this end, we have developed the Fab@Home
personal SFF kit, and are developing a user-group website to promote exchange of ideas
and improvements. The designs and software for Fab@Home will be freely distributed,
and constructing a first generation kit should cost roughly $2000. The kit design and a
working unit will be presented, along with our experience deploying a unit for public use.",,,,,,
"['Li, Wenbin', 'Martin, Austin J.', 'Kroehler, Benjamin', 'Henderson, Alexander', 'Huang, Tieshu', 'Watts, Jeremy', 'Hilmas, Gregory E.', 'Leu, Ming C.']",2021-11-10T21:50:23Z,2021-11-10T21:50:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90188', 'http://dx.doi.org/10.26153/tsw/17109']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['dynamic mixing', 'functionally graded materials', 'fabrication', 'ceramic on-demand extrusion', 'CODE']",Fabricating Functionally Graded Materials by Ceramic On-Demand Extrusion with Dynamic Mixing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8030ba9b-16f9-47e1-b8fb-1b22752a27c1/download,University of Texas at Austin,"Ceramic On-Demand Extrusion (CODE) is an extrusion-based additive manufacturing
process recently developed for fabricating dense, functional ceramic components. Presented in this
paper is a further development of this process focusing on fabrication of functionally graded
materials (FGM). A dynamic mixing mechanism was developed for mixing constituent ceramic
pastes, and an extrusion control scheme was developed for fabricating specimens with desired
material compositions graded in real time. FGM specimens with compositions graded between
Al2O3 and ZrO2 were fabricated and ultimately densified by sintering to validate the effectiveness
of the CODE process for FGM fabrication. Energy dispersive spectroscopy (EDS) was used to
compare final compositions to the original material designs. The specimen’s hardness at different
locations along the gradients was examined by micro-indentation tests. The dimensions of sintered
specimens were measured, and the effects of material composition gradients on the distortions of
sintered FGM specimens were analyzed.",,,,,,
"['Lyons, Alan M.', 'Mullins, John', 'Barahman, Mark', 'Erlich, Itay', 'Salamon, Todd']",2021-09-29T14:39:59Z,2021-09-29T14:39:59Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88184', 'http://dx.doi.org/10.26153/tsw/15125']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['superhydrophobic surfaces', 'multi-jet modeling rapid prototying']",Fabricating Superhydrophobic Surfaces with Solid Freeform Fabrication Tools,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3923016b-fd9a-467a-a307-c9a8c2a9c72f/download,University of Texas at Austin,"Superhydrophobic surfaces exhibit a range of properties such as large contact angle, low contact
angle hysteresis and decreased hydrodynamic drag. These properties make superhydrophobic
surfaces of fundamental and commercial interest as they can enable a wide variety of
applications including microfluidic components, biomedical devices, and micro-batteries.
Superhydrophobic behavior is achieved through a combination of the hydrophobicity of the
polymer and the roughness of the surface. We have used a commercially available multi-jet
modeling rapid prototyping machine to fabricate 3D objects where the superhydrophobic surface
is monolithic with the part. This approach was used to fabricate non-planar components with
novel structures including helical conduits and porous meshes. In addition, we have developed a
robotic dispensing tool that enables greater freedom of material selection. Both approaches have
been used to fabricate arrays of surface features with diameters below 175 microns and with
aspect ratios greater than 8:1. The fabrication and wetting properties of surfaces made using
these two techniques will be discussed.",,,,,,
"['Li, Wenbin', 'Ghazanfari, Amir', 'McMillen, Devin', 'Scherff, Andrew', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2021-11-02T19:08:42Z,2021-11-02T19:08:42Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89867,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['ceramic on-demand extrusion', 'zirconia', 'support structure', 'CODE']",Fabricating Zirconia Parts with Organic Support Material by the Ceramic On-Demand Extrusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0c6075ca-1641-478f-8369-c4b7bbb75696/download,University of Texas at Austin,"Ceramic On-Demand Extrusion (CODE) is an extrusion-based additive manufacturing
process recently developed for fabricating dense, functional ceramic components. This paper
presents a further development of this process and focuses on fabricating 3 mol% yttria-stabilized
zirconia (3YSZ) components that cannot be fabricated without using support structures. The 3YSZ
paste is deposited through the main nozzle, and a polycaprolactone (PCL) pellet feedstock is
melted and deposited through an auxiliary nozzle to build support structures. After a green part is
printed and dried, the support structures are removed by heating the part to ~70 °C to melt the PCL.
The part is then sintered at 1550 o
C to achieve near theoretical density. The maximum angle of
overhanging feature that can be fabricated without support was determined to be 60°. Sample parts
were fabricated and evaluated to demonstrate the effectiveness of the PCL support material and
CODE’s capability to fabricate geometrically complex parts.",,,,,,
"['Miyanaji, Hadi', 'Akbar, Junaid Muhammad', 'Yang, Li']",2021-11-02T19:02:28Z,2021-11-02T19:02:28Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89866,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['binder jetting process', 'saturation', 'composite', 'liquid phase sintering']",Fabrication and Characterization of Graphite/Nylon 12 Composite via Binder Jetting Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e39d3a71-5f41-4de9-a75d-9af04fe4167b/download,University of Texas at Austin,"Nowadays, graphite is used in many applications due to its unique combination of physical
properties. Fabrication of graphite parts has been mostly restricted to traditional manufacturing
processes (e.g. moldering), and limited works have been devoted to the feasibility of additive
manufacturing (AM) technology to produce graphite components. In the present study, the
feasibility of binder jetting additive manufacturing (BJ-AM) process in fabrication of
graphite/nylon composites is investigated. The printability of the composite parts with varying
graphite amount was experimentally examined through the adjustment of in-process parameters
(e.g. saturation level and drying energy) and post-processing curing (e.g. curing time and
temperature). The efficiency of nylon as the liquid phase sintering agent was studied via the
mechanical property evaluation of the composites. In addition, the electrical properties of the
graphite/nylon composites were investigated in order to evaluate the effectiveness of the
manufacturing method for graphite-based structures for potential functional applications.",,,,,,
"['Zhou, Bin', 'Zhou, Jun', 'Li, Hongxin', 'Lin, Feng']",2021-11-04T18:16:44Z,2021-11-04T18:16:44Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89995', 'http://dx.doi.org/10.26153/16916']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['electron beam selective melting', 'selective laser melting', 'hybrid', 'Ti6Al4V']",Fabrication and Characterization of Ti6Al4V by Selective Electron Beam and Laser Hybrid Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b6b84749-05e9-4cfd-9f2d-66bd30de9564/download,University of Texas at Austin,"A hybrid process, which combines electron beam selective melting(EBSM) and selective laser
melting(SLM), is proposed in this study. Laser is led into the vacuum chamber through the lens so
that laser can be used to fabricate the metal powder at the same time with electron beam. In this
study, Laser is used to pre-preheat the metal powder in order to preventing powder spreading and
laser is also used to fabricate the contour of the parts both inside and outside. Electron beam is used
to preheat the metal powder to the specified temperature and to fabricate the interior of the parts.
It can be sure that through the hybrid process we can fabricate the parts with both better surface
quality, higher precision and higher efficiency. Ti6Al4V samples were fabricated by selective
electron beam and laser hybrid melting. The surface roughness of the parts was measured, the
microstructures of the contour and interior were characterized using scanning electron microscopy
(SEM). The results are that as-fabricated parts have better surface quality than the parts fabricated
only using EBM process.",,,,,,
"['Holt, Nicholas', 'Galvan Marques, Lucas', 'Van Horn, Austin', 'Montazeri, Mahsa', 'Zhou, Wenchao']",2021-11-03T22:01:49Z,2021-11-03T22:01:49Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89946,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'MAPS', 'microheaters', 'MEMS', 'PID controls']",Fabrication and Control of a Microheater Array for Microheater Array Powder Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/07ac87d5-ed9d-43b6-8f26-eee2f6c9d08b/download,University of Texas at Austin,"Microheater Array Powder Sintering (MAPS) is a novel additive manufacturing process that uses
a microheater array to replace the laser of selective laser sintering as the energy source. Most of
the previous research on microheaters are for applications in gas sensing or inkjet printing. The
operation temperature and response time of the microheater array are critical for the choice of
sintering materials and printing speed for the MAPS process. In this paper, we present the
fabrication, packaging, and control of a platinum microheater array that has a target operation
temperature of 400°C and a response time of ~1 millisecond. First, we will present the fabrication
process of a microheater array. The fabricated microheater array is then packaged for easy control
and to serve as the printhead of the MAPS process. A PID controller is designed to control the
temperature response of the microheater. Finally, the effectiveness of the controller is evaluated.
Results show the fabricated microheater array satisfies the design requirements for the MAPS
process.",,,,,,
"['Dunbar, Alexander J.', 'Gunderman, Gabrielle J.', 'Mader, Morgan C.', 'Reutzel, Edward W.']",2021-11-08T22:46:32Z,2021-11-08T22:46:32Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90062', 'http://dx.doi.org/10.26153/tsw/16983']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'CT', 'Inconel 625', 'heat exchanger']",Fabrication and Quality Assessment of Thin Fins Built Using Metal Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6a542fef-8821-40ca-ac56-48534b6c5b0b/download,University of Texas at Austin,"Powder bed fusion additive manufacturing (PBFAM) is well suited for the fabrication of metallic
components with thin features that would be otherwise impractical using other manufacturing methods.
As component designs begin to take full advantage of the capabilities of additive manufacturing, so must
the capability of measurement techniques used in assessment of quality increase. The characterization of
quality may be application specific, requiring different metrics for different uses, e.g. impact on thermal
vs. mechanical considerations. Here, thin fins are built with a wide range of processing conditions to test
the limits of thin, metallic components using PBFAM. These thin fins are inspected using novel computed
tomography (CT) based measurement techniques to assess their build quality. Within the process
parameters tested, fins were successfully built thinner than manufacturer-recommended minimum wall
thickness using default process parameters. The quality of these fins was assessed utilizing post-build
non-destructive evaluation techniques developed herein.",,,,,,
"['Alayavalli, Kaushik', 'Bourell, David L.']",2021-09-30T23:57:28Z,2021-09-30T23:57:28Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88300', 'http://dx.doi.org/10.26153/tsw/15241']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['bipolar plates', 'graphite parts', 'indirect Selective Laser Sintering', 'Direct Methanol Fuel Cells']",Fabrication and Testing of Graphite Bipolar Plates for Direct Methanol Fuel Cells,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0125a682-bf6a-4093-a78a-9366dbeedd4f/download,University of Texas at Austin,"Bipolar plates made from graphite are highly desirable in fuel cell applications due to the
properties of high electrical conductivity, low weight and resistance to corrosion that graphite
possesses. However, the poor mechanical properties of natural graphite lead to prohibitive
machining costs. Graphite parts are made by indirect SLS using graphite powder mixed with a
phenolic resin binder which is subsequently burnt out. These parts fabricated using indirect SLS
have poor green strength and electrical conductivity. The current work deals with the addition of
carbon fiber to the graphite-phenolic mixture with an aim to improve green part strength and
brown part conductivity. This research work also addresses fabrication of graphite bipolar plates
for Direct Methanol Fuel Cells (DMFCs) with internal features and flow channels with different
cross-sectional geometry that are difficult to produce using conventional machining processes.",,,,,,
"['Anstaett, C.', 'Seidel, C.', 'Reinhart, G.']",2021-11-04T14:02:57Z,2021-11-04T14:02:57Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89963,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['multi-material fabrication', 'material property', 'manufacturing process', 'laser-based powder bed fusion', 'laser beam melting']",Fabrication of 3D Multi-Material Parts Using Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a325bb8-2a15-41da-be6a-9522c17c26cf/download,University of Texas at Austin,"As different branches of industry use Laser Beam Melting (LBM) and more and more materials can be
produced with it, this technology goes in and out of focus of production technologies in an industrial
environment. A big advantage of LBM is the possibility of building very complex parts and therefore
minimizing the need for raw material. The effects of this, such as lightweight-design, resource-efficient
production and reduction of manufacturing time, can even be increased if material can be used locally defined
in a part, so that one part does not have to consist of one material per fabrication-process, but at least two. Since
LBM is a powder-bed-based process, the implementation of this idea is possible by adopting the conventional
delivery device and the manufacturing process itself.
In this paper the results of a multi-material process are shown and the influences of different material properties
on the manufacturing process are derived.",,,,,,
"['Hu, Qin', 'Liu, Yaan', 'He, Yinfeng', 'Zhang, Fan', 'Wildman, Ricky', 'Tuck, Chris', 'Hague, Richard']",2021-10-21T15:38:53Z,2021-10-21T15:38:53Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89399,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['nano-composites', 'two-photon lithography', 'gold nanostructures', 'nanofabrication', 'polymerisation', 'metal salt reduction', 'metamaterials']",Fabrication of 3D Polymer-Metal Nano-Composites in a Single Step by Two-Photon Induced Polymerisation and Metal Salt Reduction,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15586193-25cf-400e-820d-17a34148549a/download,University of Texas at Austin,"Fabrication of 3D polymer-metal nano-composites in a single step by two-photon
induced polymerisation and metal salt reduction has been demonstrated in this study. Two
kinds of composites, SU8-Au and IPL-Au, based on different mechanisms of polymerisation,
have been fabricated and compared. To the best of our knowledge, this is the first
demonstration of IPL-Au nano-composites being fabricated by two-photon lithography. Extra
photoninitator is needed for the fabrication of IPL-Au composites, to provide extra free
radicals to sustain the two reactions processing at the same time. The distribution of the
generated Au nanoparticles in IPL matrix is more uniform than that in SU8 matrix. The
technique demonstrated in this study can have great application in metamaterial fabrication.",,,,,,
"['Fuhrman, Brian T.', 'Duty, Chad E.', 'Jean, Daniel L.', 'Lackey, W. Jack']",2019-09-23T17:11:34Z,2019-09-23T17:11:34Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75977', 'http://dx.doi.org/10.26153/tsw/3076']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Thermionic,Fabrication of Advanced Thermionic Emitters Using Laser Chemical Vapor Deposition-Rapid Prototyping 498,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4f821899-c292-4088-a6f5-721bc88210dc/download,,Laser Chemical Vapor Deposition-Rapid Prototyping (LCVD-RP) is a relatively new manufacturing process. Its capabilities are ideally suited for the manufacturing of a type of electron emitter called an integrated-grid thermionic emitter. The integrated-grid thermionic emitter is composed of wagon wheel-like structures of alternating layers of boron nitride and molybdenum on tungsten. The goal of this paper is to determine the feasibility of using LCVDRP technology to manufacture advanced thermionic emitters.,,,,,,
"['Tan, George Z.', 'Zhou, Yingge']",2021-11-16T15:21:34Z,2021-11-16T15:21:34Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90311', 'http://dx.doi.org/10.26153/tsw/17232']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['divergence electrospinning', '3D nanofiber scaffold', 'tissue engineering']",Fabrication of Aligned Nanofibers Along Z-Axis – A Novel 3D Electrospinning Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6a776f18-f904-4e37-8348-7519b97e11d6/download,University of Texas at Austin,"This study presents a 3D fabrication technique of nanofibrous scaffold for tissue engineering. A
divergence static electric field was introduced in an electrospinning system to induce a self-assembly of aligned nanofibers into a tunable 3D architecture with thickness ranging from 2-12
mm. The effects of collector configuration on polycaprolactone (PCL) nanofiber attributes were
investigated. Human fibroblast cells were cultured on the nanofiber scaffold in vitro for 7 days. It
was found that the width and inclination angle of the collector influenced the nanofiber density
distribution. The cells proliferated on the scaffold and organized as a fibrous matrix which
mimicked the microstructure of native musculoskeletal tissues.",,,,,,
"['Ott, A.', 'Heinzl, J.', 'Janitza, D.', 'Pelzer, R.']",2020-02-20T18:23:23Z,2020-02-20T18:23:23Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80034', 'http://dx.doi.org/10.26153/tsw/7056']",eng,2004 International Solid Freeform Fabrication Symposium,Open,computer tomography,Fabrication of Bone Substitute Material by Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/187ae983-7179-4f7f-95fc-f8c5ad6cf016/download,,"Bone tissue engineering has gained much attention in recent years. A key requirement in this
field is the development of scaffold structures, on which cells adhere. This can be done by
fabricating scaffolds by direct procedures like 3D-printing or by indirect procedures like casting.
With the 3D-printing process different structures were build up by using hydroxyapatite powder
(HA) and a special binder material. Afterwards the printed 3D structures were sintered.
For the casting process molds have been made of different resins by stereolithography and other
processes using polymers and waxes. These structures were filled by a suspension of HA. By
heating the resulting polymer/ceramic composite to a specific temperature it is possible to
combust the polymer or wax. By further heating the remaining body, the HA is sintered.
Compared to the 3D printing a better resolution can be obtained here. But there are restrictions
regarding the ratio of polymer and the HA ceramic during the heating process which means a
limitation for the level of porosity.",,,,,,
"['Snelling, Dean', 'Williams, Christopher', 'Suchicital, Carlos', 'Druschitz, Alan']",2021-10-21T19:27:37Z,2021-10-21T19:27:37Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89429,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['binder jetting', 'cellular cordierite', 'ceramic preforms', 'metal matrix composites']",Fabrication of Cellular Cordierite Performs via Binder Jetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c8ba8365-1846-4671-97b3-c00ede38bfa6/download,University of Texas at Austin,"Metal Matrix Composites (MMCs) combine two dissimilar materials – a metal as the matrix
and a ceramic as the charge or insert to provide unique properties, e.g. low density, high specific
strength, high specific modulus, and wear resistance. The ceramic inserts in these composite
materials are limited to ceramic fibers and open cell stochastic ceramic foams due to geometric
constraints imposed by traditional manufacturing processes. The geometric design freedom
offered by Additive Manufacturing (AM) could enable a designer to realize ceramic preforms
with complex cellular geometries that are designed to achieve multiple functions (e.g., low mass
and increased stiffness). The goal of this work is to explore the use of Binder Jetting as a means
of fabricating cordierite parts of designed mesostructure for use as ceramic preforms for MMCs.
In this paper, the authors describe their exploration of the appropriate printing process
parameters and post-process sintering parameters that enable successful fabrication of complex
cordierite artifacts. Measurements of bulk density, linear shrinkage, porosity, and x-ray
diffraction are conducted on pre- and post-sintered printed cordierite structures.",,,,,,
"['Deckard, Lucy', 'Claar, T. Dennis']",2018-05-03T19:13:43Z,2018-05-03T19:13:43Z,1993,Mechanical Engineering,doi:10.15781/T2251G32W,http://hdl.handle.net/2152/65060,eng,1993 International Solid Freeform Fabrication Symposium,Open,"[""Lanxide's matrix"", 'CMC', 'Ceramix Matrix Composites', 'DIMOX']",Fabrication of Ceramic and Metal Matrix Composites From Selective Laser Sintered Ceramic Preforms,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4d827fa3-21f7-46e1-820d-d1a820bbf7c6/download,,"This paper will discuss the tool~less fabrication of functional advanced comJX>sites by infusion of a
ceramic or metal matrixinto Selective Laser Sintered(SLS) porous ceranU~preforms using
Lanxide'spatentedmatrix infusionproc;esses. The fabri~ationofJX>rous preformS of particulate
cerami~sby SLS atthe University ofTexas at Austin is described in a companion paper. The
PRlME}(TI4 pressureless metal infi1trationp~ss was used to infiltrate<alUIninum matrices into
both SiC and Al~03 particulate SLS prefonns to make metal matrix comJX>sites withoutthe use of
tooling. Also, SiC I~03 ceramic matrix comJX>sites were fabricated using the DIMO}(TI4
directed metal oxiJation process to grow an Al20 3 matrix into porous SiC particulate SLS
preforms. Measured properties and microstructures of the resulting composites will be presented
and compared to similar comJX>sites made using conventionally fabricated preforms. The rapid
prototyping of a SiCiAIMMC electronic power package to near~net shape from an SLS preform
will also be describeQ.",,,,,,
"['Wang, X.', 'de Caussin, D.']",2021-11-09T21:05:23Z,2021-11-09T21:05:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90167', 'http://dx.doi.org/10.26153/tsw/17088']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['ceramics', 'photopolymers', 'digital light projection', 'tape casting', 'projection-based stereolithography']",Fabrication of Ceramic Parts Using a Digital Light Projection System and Tape Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e62d7a8b-93ee-4427-9c92-5c918c0e99c4/download,University of Texas at Austin,"In this paper, fabrication of ceramic parts using projection-based stereolithography by
curing the mixture of ceramic and photopolymers was investigated. A stereolithography device
with a UV LED projection light source was built. A series of resin and ceramic powders, including
alumina and zirconia, were experimented to explore the viscosity of mixture and the resultant part
quality. It was found that commercial photopolymers are not suitable for this purpose due to the
small cure depth. A customized photopolymer without photoinhibitor and optimized photoinitator
has demonstrated success in producing 3D ceramic green bodies. It was found that the viscosity
was very high for all of the mixtures with high ceramic loading which will influence the recoating
process. Therefore, tape casting was used to apply the slurry during the build process.",,,,,,
"['Choi, Jae-Won', 'Park, In-Baek', 'Wicker, Ryan', 'Lee, Seok-Hee', 'Kim, Ho-Chan']",2021-09-28T17:45:32Z,2021-09-28T17:45:32Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88134', 'http://dx.doi.org/10.26153/tsw/15075']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['microstereolithography', '3D micro-scale scaffolds', 'tissue enginnering']",Fabrication of Complex 3D Micro-Scale Scaffolds and Drug Delivery Devices using Dynamic Mask Projection Microstereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08a55ab2-e04f-4626-bd33-146a3d91c7bc/download,University of Texas at Austin,"Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissue 
engineered scaffolds with controlled biochemical and mechanical micro-architectures. A 
μSL system for tissue engineering was developed using a Digital Micromirror Device 
(DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for 
crosslinking the photoreactive polymer solution. The μSL system was designed with x-y 
resolution of ~2 μm and a vertical (z) resolution of ~1 μm. To demonstrate the use of μSL in 
tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight 
of ~1200 Da. The viscosity of the PPF was reduced to ~150 cP (at 50 o
C) by mixing with 
diethyl fumarate (DEF) in the ratio of 7:3 (w/w). Finally, ~2 % (w/w) of (bis(2,4,6-
trimethylbenzoyl) phenylphosphine oxide (BAPO) was added to the solution to serve as a 
photoinitiator. Cure depth experiments were performed to determine the curing 
characteristics of the synthesized PPF, and the resulting system and photopolymer were used 
to construct a variety of 3D porous scaffolds with interconnected pores between 100 and 150 
μm and a micro-needle array with height of ~800 μm and individual tip diameters of ~20 μm. 
SEM and microscope images of the micro-architectures illustrate that the developed μSL 
system is a promising technology for producing biodegradable and biocompatible 
microstructures.",,,,,,
"['Lous, G.M.', 'Cornejo, I.A.', 'McNulty, T.F.', 'Safari, A.', 'Danforth, S.C.']",2019-03-01T17:37:35Z,2019-03-01T17:37:35Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73518', 'http://dx.doi.org/10.26153/tsw/668']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition', 'Ceramics']",Fabrication of Curved Ceramic / Polymer Composite Transducers for Ultrasonic Imaging Applications by Fused Deposition of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a1977c2-3962-4a74-9082-ede968979961/download,,"Fused Deposition of Ceramics (FDC), developed at Rutgers University, is a Solid Freeform Fabrication (SFF) technique where a three-dimensional green ceramic object is built
layer by layer, starting from a Computer Aided Design (CAD) file of the object. This technique
was used to build novel piezoelectric ultrasonic transducers for medical imaging applications.
Curved ceramic skeletons for 2-2 (parallel ceramic / epoxy plates) composite transducers were
built by FDC. The design's curvature can be tailored in the CAD file. Therefore, the final
composite requires very little machining. In the FDC-built green parts, the ceramic plates were
500 um thick and the spacing between the plates was 1270 um. The FDC green samples were
subjected to a slow binder burnout cycle at 550°C for 4 hours, using a heating rate of 8°C per
hour, then sintered at 1285°C for 1 hour. Physical characterization of the samples revealed that
95% ofthe theoretical density was achieved. The ceramic plates shrunk 20% in height as well as
in width. The shrinkage was of only 16% in the direction parallel to the plates. Optical
microscopy and SEM were performed on green and sintered samples. The results of these
characterizations are reported in this paper as well as the electromechanical properties of the
final composites and of FDC bulk samples.",,,,,,
"['Gervasi, Vito', 'Cook, Douglas', 'Rizza, Robert', 'Kamara, Sheku']",2021-09-29T17:44:46Z,2021-09-29T17:44:46Z,10/7/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88199', 'http://dx.doi.org/10.26153/tsw/15140']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['custom orthosis', 'rapid prototyping', 'additive manufacturing', 'laser sintering', 'foam molding', 'polypropylene', 'polyamide']",Fabrication of Custom Dynamic Pedorthoses for Clubfoot Correction via Additive-Based Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59de9528-2ac6-4e0e-8b9a-9c44a9475b2e/download,University of Texas at Austin,"Additive technologies have created many opportunities to improve the quality of life for patients
in a range of medical applications. This paper provides an overview of how several of these
technologies were leveraged to transform custom pedorthosis designs into physical, end-use,
custom pedorthoses for clubfoot patients. The pedorthoses that were produced are currently
being tested on the respective patients for their improvement in mobility and degree of clubfoot
correction, and will continue through early 2010. The advantage of this approach is the
reduction in labor and the increase in degrees of design freedom available, compared to
conventional methods of fabricating orthotic devices. Several new approaches for fabricating
custom orthotic devices that were explored, and the related results, are discussed.",,,,,,
"['Alayavalli, Kaushik', 'Bourell, David L.']",2020-03-11T14:35:42Z,2020-03-11T14:35:42Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80245', 'http://dx.doi.org/10.26153/tsw/7264']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'SLS', 'DMFC', 'Direct Methanol Fuel Cell']","Fabrication of Electrically Conductive, Fluid Impermeable Direct Methanol Fuel Cell (DMFC) Graphite Bipolar Plates by Indirect Selective Laser Sintering (SLS)",Conference paper,https://repositories.lib.utexas.edu//bitstreams/26192c1b-6071-4779-abe9-a33db912ca24/download,,"Graphite bipolar plates are highly desirable due to their properties of high electrical conductivity
and low weight but are associated with prohibitive machining costs arising from poor mechanical
properties. Bipolar plates made by indirect Selective Laser Sintering (SLS) offer the advantages
of complex part production in shorter times at lower cost. Due to the nature of the SLS process,
the as-produced (green part) plates are porous and possess low electrical conductivity which can
be improved by carbonizing the phenolic resin binder at high temperatures (brown part). It has
been found that the electrical conductivity increases significantly (> 200 S/cm) with a
corresponding increase in pyrolyzing temperature which correlates well with literature on the
carbonization of phenol formaldehyde resins. The brown parts are subsequently infiltrated with
low viscosity (~5 - 10 cps) cyanoacrylate to seal up the open pores, rendering the plates fluid
impermeable.",,,,,,
"['Choi, Jae-Won', 'Quintana, Rolando', 'Wicker, Ryan B.']",2021-09-28T17:41:17Z,2021-09-28T17:41:17Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88132', 'http://dx.doi.org/10.26153/tsw/15073']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['micro-fluidic devices', 'embedded horizontal micro-channels', 'line-scan stereolithography', 'micro-fluidic fabrication', 'micro-channel fabrication']",Fabrication of Embedded Horizontal Micro-Channels Using Line-Scan Stereolithogrpahy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ec6c06f-4663-4b08-a1e5-cdcfddbc70ed/download,University of Texas at Austin,"In an effort to directly and rapidly manufacture micro-fluidic devices with embedded horizontal 
micro-channels on the order of tens of microns, a method was developed for using current 
commercially available line-scan stereolithography (SL) technology. The method consisted of 
inserting a wire of specified diameter during the build, building around the inserted wire, and 
removing the wire once fabricated leaving a channel with a circular cross-sectional geometry 
equivalent to the wire diameter. Demonstration of the technique using 31.6 µm, 57.2 µm and 
83.5 µm wire was performed using a 3D Systems Viper si2TM SL system and DSM Somos® WaterShedTM resin. By embedding the wire and building around the insert, the down-facing 
surfaces were supported during fabrication enabling successful and accurate fabrication of 
embedded micro-channel geometries. A method for successful fabrication was developed that 
involved first building an open micro-channel, interrupting the SL process and inserting the wire, 
and then capping over the wire with multiple layers. After fabricating a part with a micro-wire, 
the micro-channel was produced by simply pulling the wire out of the part. Scanning electron 
microscope (SEM) images were used to examine and measure the geometries of the fabricated 
micro-channels, and a statistical design of experiments was performed to show that the process 
was capable of producing accurate horizontal micro-channels. It is expected that this process 
will enable unique micro-fluidic and other applications of micro-channel fabrication to be 
pursued using commercial line-scan SL.",,,,,,
"['Sun, Lianchao', 'Jakubenas, Kevin J.', 'Crocker, James E.', 'Harrison, Shay', 'Shaw, Leon L.', 'Marcus, Harris L.']",2018-12-05T20:42:23Z,2018-12-05T20:42:23Z,1997,Mechanical Engineering,doi:10.15781/T2MC8S278,http://hdl.handle.net/2152/71418,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'thermocouples']",Fabrication of In-situ SiC/C Thermocouples by Selective Area Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee3abc95-9f1a-4428-b768-5f0dfab6318b/download,,"With the intrinsic nature to process relatively small features, selective area laser
deposition (SALD) is a potential technique to fabricate complex shaped macro-components with
in-situ high-resolution micro-devices. In this study, SALD was used to deposit in-situ silicon
carbide/carbon (SiC/C) thermocouples on alumina and silicon carbide substrates with a C02
laser. Tetramethylsilane (TMS) and acetylene (C2H2) were chosen as precursors for deposition of
the silicon carbide and carbon lines respectively. The electromotive force (emf) ofthe deposited
thermocouple was measured and found to respond sensitively to temperature variations from
room temperature to 800°C. The effect ofthe deposition parameters on the product morphology
was also investigated.",,,,,,
"['Jiang, Wenhui', 'Kovacevic, Radovan']",2019-11-21T18:23:33Z,2019-11-21T18:23:33Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78557', 'http://dx.doi.org/10.26153/tsw/5613']",eng,2003 International Solid Freeform Fabrication Symposium,Open,TiC/Steel,Fabrication of Laser Deposited TiC/Steel Matrix Composite Coatings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/16bf826d-69c3-45da-9b6f-1fb838b5ac28/download,,"The present work investigates the effect of laser scanning beam speeds and the content of
TiC in injected powder on morphologies and microstructures of laser deposited beads of a
TiC/H13 tool steel composite. The results show that the beam scanning speeds affect the size and
morphology of the beads. During laser processing, TiC melts, decomposes, and subsequently, a
number of fine TiC precipitates form during cooling that are uniformly distributed in the tool
steel matrix. The beam scanning speeds and the amount of injected TiC exert a strong influence
on the morphology and size of the fine TiC precipitates. It is believed that the precipitated TiC is
the primary phase in hypereutectic Fe-TiC. Rapid cooling develops martensite with retained
austenite in a steel matrix. The precipitated TiC can refine grains of the steel matrix as a
solidified nucleus. TiC/H13 tool steel composite coatings with various contents of TiC were
produced using the laser deposition processing technique.",,,,,,
"['Brown-Moore, Tosh Kāneala', 'Balaji, Srivatsan', 'Williams, Tyler', 'Lipton, Jeffrey']",2023-01-26T14:27:57Z,2023-01-26T14:27:57Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117306', 'http://dx.doi.org/10.26153/tsw/44187']",eng,2022 International Solid Freeform Fabrication Symposium,Open,voronoi,Fabrication of Liquid-Filled Voronoi Foams for Impact Absorption Using Material Jetting Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/052f20d0-ea8f-4a86-9d24-69b31bd937aa/download,,"An important consideration in the design of any mechanical system is its ability to isolate 
and dissipate vibrational and impact energy. Closed-cell foams utilize cell crumpling to absorb 
energy, relying solely on viscoelastic effects for damping. Liquids, however, can generate large 
amounts of damping from fluid channel friction and turbulence. We produced closed-cell foams 
that are liquid filled, resulting in tunable materials that absorb energy better than either component 
on their own, using a Voronoi generation model and a J750 printer that could jet curable and 
incurable liquids. We found that by changing the wall thickness and liquid percentage, we achieve 
a stiffness range of 4.1 N/mm to 80 N/mm. Our work introduces this new class of damping 
metamaterial that can absorb tunable amounts of energy per unit volume. These impact-absorbing 
structures may benefit applications such as protective equipment, healthcare, and automotive 
industries.",,,,,,
"['Brueckner, Frank', 'Riede, Mirko', 'Mueller, Michael', 'Marquardt, Franz', 'Knoll, Matthias', 'Willner, Robin', 'Seidel, André', 'Lopéz, Elena', 'Leyens, Christoph', 'Beyer, Eckhard']",2021-11-08T21:48:50Z,2021-11-08T21:48:50Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90050', 'http://dx.doi.org/10.26153/tsw/16971']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'multi-material alloys', 'metal alloys', 'highly-loaded areas', 'fabrication']",Fabrication of Metallic Multi-Material Components Using Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2697640-2a67-4425-a148-f905bf13899c/download,University of Texas at Austin,"Meanwhile, Laser Metal Deposition (LMD) is a well-known Additive Manufacturing technology
used in various industrial branches as energy, tooling or aerospace. It can be used for the
fabrication of new components but also repair applications. So far, volume build-ups were mostly
carried out with one single material only. However, loading conditions may strongly vary and,
hence, the use of more than one material in a component would yield major benefits. By means of
multi-material build-ups, cost-intensive alloys could be used in highly-loaded areas of the part,
whereas the remaining part could be fabricated with cheaper compositions. The selection of
combined materials strongly depends on the requested thermo-physical and mechanical properties.
Within this contribution, possibilities of material combinations by LMD and selected examples of
beneficial multi-material use are presented.",,,,,,
"['Johnson, Ryan W.', 'Bondi, Scott N.', 'Jean, Daniel L.', 'Duty, Chad E.', 'Jang, Ming Xuan', 'Lackey, W. Jack']",2019-10-09T16:07:25Z,2019-10-09T16:07:25Z,2001,McDonald Observatory,,"['https://hdl.handle.net/2152/76148', 'http://dx.doi.org/10.26153/tsw/3237']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Fabrication of Multi-Layered Carbon Structures Using LCVD,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b451753-a453-4d65-8624-d50959581e73/download,,"Others have used Laser Chemical Vapor Deposition (LCVD) to create 3-D fibrous
structures and helical springs. Current research efforts focus on the creation of more advanced
three-dimensional carbon objects through the use of multi-layered deposition. Multi-layered
structures require an understanding of interlayer adhesion and the propagation of geometric
anomalies through multiple layers. An important aspect in minimizing these shape anomalies is
the implementation of closed loop temperature control. Several laminated carbon structures are
presented with discussions and observations about the fabrication process and visual
characteristics of each. The major issues in using LCVD to create multi-layer carbon structures
are addressed.",,,,,,
"['Zhang, Wande', 'Han, Li-Hsin', 'Chen, Shaochen']",2021-09-28T18:18:14Z,2021-09-28T18:18:14Z,9/24/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88144', 'http://dx.doi.org/10.26153/tsw/15085']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['nanoimprinting molds', 'acrylic polymer', 'two-photon polymerization']",Fabrication of Nanoimprinting Molds with Acrylic Polymer by Two-Photon Polymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a1e7e976-c564-4329-8e9c-c34125e07e0e/download,University of Texas at Austin,"We demonstrate the plausibility of making low-cost nanoimprinting molds with acrylic
polymer using femtosecond-laser-induced two-photon polymerization (TPP) technique.
A Ti:sapphire femtosecond laser was used to induce TPP in dipentaerythritol
pentaacrylate to make nanostructures, the nanoimprinting mold, on pretreated glass
substrate. A layer of fluoro-silane was then grown on the surface of the mold to
promote the release of the mold after imprinting. To test the imprinting capacity of the
mold, poly (ethylene glycol) diacrylate was patterned by the mold and the results were
analyzed by a scanning electron microscope (SEM).",,,,,,
"Partanen, Jouni P.",2018-11-09T14:56:37Z,2018-11-09T14:56:37Z,1996,Mechanical Engineering,doi:10.15781/T23F4M712,http://hdl.handle.net/2152/69922,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLA', 'RP&M technologies', 'laser']",Fabrication of Parts Containing Small Features using Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9b3e48e7-f682-4c1c-9a3b-54f27a9053fa/download,,"The StereoLithography (SL) process has benefited from many advances in the last four to
five years. These include new resins with reduced shrinkage and curl distortion, enhanced
software, and improved scanning techniques. One can produce highly accurate parts for most
dimensions within a few mils of the design value as shown in numerous accuracy and
benchmarking studies. SLA systems use a laser beam focused to a spot size of 200 -250 ~m.
This limits the range of applications where SL can provide accurate models to parts which do not
contain very small features i. e. wall thickness values less than about 300 ~m. Industries that
manufacture products involving components with small features include electronics and medical.
In this presentation we describe an extension of the SL technology to applications
involving small features. This capability is achieved by reducing the laser focal spot size in an
SLA-250 to 75 ~m. The technological principle behind the spot size reduction is described in
the presentation, together with process issues and applications ofthe technology.",,,,,,
"['Chen, Ssuwei', 'Bourell, David L.', 'Wood, Kristin L.']",2020-02-13T19:26:02Z,2020-02-13T19:26:02Z,8/23/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79965', 'http://dx.doi.org/10.26153/tsw/6990']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Fabrication of PEM Fuel Cell Bipolar Plates by Indirect SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd5b6342-956b-46dc-9858-ea9bcbe92ca1/download,,"The paper presents a new manufacturing technique involving Selective Laser
Sintering (SLS) for proton exchange membrane fuel cell (PEMFC) bipolar plate
fabrication. A material system for bipolar plate fabrication was identified to satisfy both
the cell performance requirement and SLS operation restriction. Carbonization and liquid
epoxy infiltration are subsequently performed following the completion of SLS green
bipolar plate. The finished SLS bipolar plate showed impressive surface finish and
mechanical strength, and a single fuel cell was assembled with two SLS end plates and
membrane electrode assembly (MEA) in between. Various physical property tests were
performed with positive results. Fuel cell performance (voltage vs. current density,
voltage vs. time, etc.) will be assessed in the near future.",,,,,,
"['Rogers, W.E.', 'Crawford, R.H.', 'Beaman, J.J.', 'Walsh, N.E.']",2018-04-17T16:44:33Z,2018-04-17T16:44:33Z,1991,Mechanical Engineering,doi:10.15781/T2XD0RF4F,http://hdl.handle.net/2152/64331,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['SLS workstation', 'CAD system', 'SLS']",Fabrication of Prosthetic Socket by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c8017c2a-f34b-455f-9abc-c3f776b457a7/download,,"Solid freeform fabrication technologies offer exciting possibilities for improving
product quality by direct manufacture of products. .One example of such product
improvement is the fabrication of artificial limb sockets by selective laser sintering (SLS).
Currently these sockets are produced at the University of Texas Health Science Center at
San Antonio by digitizing the residual limb with a 3D laser scanner, modifying this
geometry appropriately using a proprietary CAD system, producing a mold with a
computer-controlled milling machine, and vacuum forming the final product. This paper
describes a new manufacturing technique whereby the digital socket data from the CAD
system provide input to a SLS workstation to produce the final socket directly, without the
intermediate step of fabricating a mold pattern. The advantages of this process include
integration of the prosthesis attachment fitting and socket as one component and greater
control of local socket geometry for superior stress relief characteristics.",,,,,,
"['Pan, Yayue', 'Chen, Yong', 'Zhou, Chi']",2021-10-04T21:34:12Z,2021-10-04T21:34:12Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88355', 'http://dx.doi.org/10.26153/tsw/15294']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'surface finish', 'layer stair-stepping', 'mask projection stereolithography']",Fabrication of Smooth Surfaces Based on Mask Projection Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e1a9904-9935-488c-a0d5-3b6a70761e8e/download,University of Texas at Austin,"The surface finish is critical for applications such as micro-fluid mixing and self-assembly that
requires smooth fluidic flow and mechanical rotation respectively. However, in layer-based additive
manufacturing processes, it is well known that the stair-stepping effect exists in the fabricated surfaces
since a three-dimensional model is approximated by a set of two-dimensional layers. The fabricated
surfaces are especially poor for the ones that are close to the horizontal plane. In this paper a novel
approach for achieving improved surface finish has been presented for the mask-image-projection-based
Stereolithography (MIP-SL) process. Theoretical models and parameter characterization are presented
with experimental verification. The developed approaches have been incorporated in the process planning
of the MIP-SL process. Multiple test cases based on various types of curved surfaces have been
performed. A comparison of the built results based on the traditional and the newly developed
approaches has been discussed to illustrate the effectiveness of our method.",,,,,,
"['Jayabal, Dinesh Krishna Kumar', 'Zope, Khushbu', 'Cormier, Denis']",2021-11-09T20:17:03Z,2021-11-09T20:17:03Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90154', 'http://dx.doi.org/10.26153/tsw/17075']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['engineered lattice structures', 'lattice structures', '4043 aluminum', 'molten aluminum droplets', 'magneto hydro dynamic jetting', 'jetting']",Fabrication of Support-Less Engineered Lattice Structures via Jetting of Molten Aluminum Droplets,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d8601c40-69a5-4afd-a3c9-37de48335991/download,University of Texas at Austin,"Magneto Hydro Dynamic (MHD) jetting is a promising new metal additive manufacturing
technique that employs on-demand jetting of molten metal droplets onto a moving substrate. A
particularly unique aspect of the process is its potential to print down-facing features without the
need for support structures. Under suitable droplet jetting conditions affecting time and
temperature, each droplet at least partially solidifies prior to impact of the next incoming molten
metal droplet. The combination of droplet jetting frequency and substrate velocity dictates the stepover distance between incoming droplets. With relatively large droplet step-over distances (or
equivalently small percentage of droplet overlap), it is possible to print unsupported down-facing
features that are nearly parallel to the X-Y build platform. In this paper, we describe initial results
in which engineered lattice structures have been printed using 4043 aluminum using this approach.
A parametric study that maps jetting frequency and droplet step-over distance with the resulting
lattice strut angle is presented. With careful control of jetting parameters, we show that it is
possible to print nearly horizontal lines without any support.",,,,,,
"['Liu, Weiping', 'DuPont, John']",2019-10-22T18:19:57Z,2019-10-22T18:19:57Z,2002,McDonald Observatory,,"['https://hdl.handle.net/2152/76334', 'http://dx.doi.org/10.26153/tsw/3423']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Matrix,Fabrication of Titanium Aluminide Matrix Composites by Laser Engineered Net Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fd123a1-5d73-42de-9432-98c80d922a64/download,,"TiAl-based titanium aluminide alloys and their composites reinforced with ceramic
particles are considered to be important candidate materials for high temperature structural
applications. Laser Engineered Net Shaping (LENS) is a layered manufacturing process, which
involves laser processing fine powders into three-dimensional components directly from a CAD
design. In this work, the LENS process has been employed to fabricate carbide particle
reinforced titanium aluminide matrix composites using TiC and gas-atomized Ti-48Al-2Cr-2Nb
powders as the feedstock materials. The composites deposited by the LENS process exhibited a
susceptibility to solid-state cracking due to the generated high thermal stresses. The
microstructures of the laser-deposited monolithic and composite titanium aluminide materials
were characterized using light optical microscopy and XRD techniques. Effects of the LENS
processing parameters on the cracking susceptibility and microstructure were studied. Crack-free
deposits can be fabricated by preheating the substrate to 450~500°C during LENS processing.
The fabricated composite deposits exhibit a hardness of more than twice the value of the
Ti-6Al-4V alloy.","The authors gratefully acknowledge support of this work by the National Science
Foundation through a PECASE Award, Grant No. DMI 9983968, made through the Division of
Manufacturing and Industrial Innovation of NSF.",,,,,
"['Beal, V. E.', 'Erasenthiran, P.', 'Hopkinson, N.', 'Dickens, P.', 'Ahrens, C. H.']",2020-02-12T16:03:21Z,2020-02-12T16:03:21Z,8/17/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79944', 'http://dx.doi.org/10.26153/tsw/6970']",eng,2004 International Solid Freeform Fabrication Symposium,Open,"['Functionally Graded Material', 'laser fusion']",Fabrication of X-Graded H13 and Cu Powder Mix Using High Power Pulsed Nd:YAG Laser,Conference paper,https://repositories.lib.utexas.edu//bitstreams/25bb2ab4-7951-4f33-9039-0041a0718066/download,,"The manufacturing of Functionally Graded Material (FGM) parts using Solid Free Form
manufacturing technologies has been carried out since early 1980. At present, most of the
powder manufacturing techniques are being focused on layering powder with different
powder blend compositions with Z gradients (graded in direction of layer build). Although,
there are a few researchers working on multi powder feeder and deposition system, the study
of laser fusion of the deposited powder (by a powder deposition system) is minimum or not
known to date. Consequently, the manufacturing of functionally graded structures is still
geometry limited. This work was focused on the manufacturing of X-graded (graded along the
powder bed plane) specimens with H13 tool steel and Cu mix. Five bimodal powder blends
were used with a multi-container feed hopper to spread powder layers for the selective laser
fusion of the powder. The powder was fused using a high power Nd:YAG pulsed laser using a
specific scanning strategy to reduce porosity. Specimens were produced with graded Cu
within the H13 matrix. The specimens were analysed for dimensional accuracy,
microstructure, porosity, cracks and micro hardness of the FGM.",,,,,,
"['Zhang, Yicha', 'Harik, Ramy', 'de Backer, Wout', 'Bernard, Alain']",2021-10-26T17:48:09Z,2021-10-26T17:48:09Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89537,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['build orientation', 'alternatives', 'facet clusters', 'additive manufacturing']",A Facet Cluster-Based Method for Alternative Build Orientation Generation in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b7cc879-da1a-4f21-b305-1de1f20bd664/download,University of Texas at Austin,"Build orientation determination is an important pre-processing step in Additive Manufacturing. To identify an
optimal build orientation, there are two main tasks, generating a set of alternative orientations and evaluating
these alternatives with pre-set criteria. To solve the first task, currently there are two categories of methods,
exhaustive computing and continuous surface decomposition. However, for exhaustive computing methods, the
infinite original alternative orientation space is an obstacle, especially when considering multiple objectives.
While the other type of methods have difficulty on surface separation and shape boundary recognition when
facing complex CAD models. To tackle of these obstacles, this paper introduces a new method applying a
statistical tool to form facet clusters for decomposing an STL model in a discrete way. The formed facet clusters
can be used to efficiently generate meaningful alternative build orientations and can also be used to predict
surface quality distribution over a part model for further process planning or design iteration.",,,,,,
"['Zhang, Zhicheng', 'Fidan, Ismail']",2021-11-30T21:04:13Z,2021-11-30T21:04:13Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90548', 'http://dx.doi.org/10.26153/tsw/17467']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['failure detection', 'deep learning', 'printing error', 'fused filament fabrication']",Failure Detection of Fused Filament Fabrication via Deep Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3e0ec34-1e71-4653-a903-8f8f2dff08b0/download,University of Texas at Austin,"Additive Manufacturing (AM) is used in several fields and its utilization is
growing sharply in almost every aspect of daily life. The focus of the current studies
in the AM field is generally focused on the development of new technologies and
materials. In addition, there is a limited number of research studies on the
troubleshooting aspects of the AM processes. For the most commonly used Fused
Filament Fabrication (FFF) process, the waste of material and time due to the printing
errors are still an unsolved problem. The typical errors such as nozzle jamming and
layer mis-alignment are inevitable during the printing process, and thus cause the
failure of printing. It is a challenging task to clearly understand the physical behavior
of FFF process with uncertainty, due to the phase transition and heterogeneity of the
materials. Therefore, to detect the printing error, this research proposes a deep
learning (DL) based printing failure detection technique. In this study, DL is utilized
to monitor the printing process, and detect its failures. This newly developed DL
framework was beta-tested with a commercially available FFF setup. The beta testing
results showed that this technique could effectively detect printing failures with high
accuracy.",,,,,,
"['Zhang, Runyu', 'Jiao, Yuxin', 'Paniagua, Christopher', 'Tian, Yi', 'Lu, Hongbing', 'Li, Wei']",2023-01-27T17:55:27Z,2023-01-27T17:55:27Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117349', 'http://dx.doi.org/10.26153/tsw/44230']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Wire-arc additive manufacturing (WAAM)', 'porosity propagation', 'in-situ X-ray  micro-computed tomography (μCT)']",The Failure of Wire-Arc Additive Manufactured Aluminum Alloys with Porosities under Loadings as Observed by In-situ X-Ray Micro-Computed Tomography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9446a9a8-5c74-4198-bbce-e98b7f29c3bd/download,,"Wire-arc additive manufactured aluminum alloys (WAAM 4043 Aluminum) are widely 
used in many industries. Porosities are known to exist within the WAAM aluminum alloys, which 
greatly reduces the usability and reliability of such parts. In this study, WAAM aluminum alloy 
samples with porosities are manufactured using a Fronius (TPS 320i) MIG/MAG welding and 
ABB (IRB 140) robot system. The porosities generated inside the samples and the porosity 
evolution under the uniaxial tension are observed using in-situ X-ray micro-computed tomography 
(μCT). The μCT system with an integrated mechanical loading frame provides in-situ volumetric 
images of the specimens while loadings are applied. The porosity evolution of the WAAM 
aluminum samples and the propagation of the internal pores are assessed. This work provides 
direct experimental observations and evaluations of the influence of porosities on the mechanical 
behavior of WAAM aluminum alloys under loadings.",,,,,,
"['Carton, M.A.', 'Ganter, M.']",2021-11-30T21:44:13Z,2021-11-30T21:44:13Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90560', 'http://dx.doi.org/10.26153/tsw/17479']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['auxetic structures', 'fused deposition modeling', 'FDM printing']",Fast and Simple Printing of Graded Auxetic Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19119ee8-79db-4f3f-992a-ed1b33e8c0f9/download,University of Texas at Austin,"One of the great promises of additive manufacturing is the ability to build parts with volumetrically
graded parameters that would be difficult or impossible with traditional manufacturing. This paper
presents a method of procedural generation and unsupported fabrication of 2D objects patterned
with functionally graded auxetic (negative Poisson’s ratio) cellular structures using commercially
available FDM printers. Several types of two-dimensional auxetic pattern are fabricated. The
resulting printed objects exhibit a graded response to load, deforming corresponding to local patterning. Deformation is studied using imaging of loaded structures and applications in several
areas are considered.",,,,,,
"['Yan, Lei', 'Pan, Tan', 'Newkirk, Joseph W.', 'Liou, Frank', 'Thomas, Eric E.', 'Baker, Andrew H.', 'Castle, James B']",2021-11-09T19:07:41Z,2021-11-09T19:07:41Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90128', 'http://dx.doi.org/10.26153/tsw/17049']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['thermal history', 'heat source', 'thermal prediction', 'large-scale parts', 'finite element analysis', 'laser metal deposition']",Fast Prediction of Thermal History in Large-Scale Parts Fabricated Via a Laser Metal Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9e55e1f-3f54-43f4-bfa4-ecae5f3a49f9/download,University of Texas at Austin,"Laser metal deposition (LMD) has become a popular choice for the fabrication of near-net
shape complex parts. Plastic deformation and residual stresses are common phenomena that are
generated from the intrinsic large thermal gradients and high cooling rates in the process. Finite
element analysis (FEA) is often used to predict the transient thermal cycle and optimize processing
parameters; however, the process of predicting the thermal history in the LMD process with the
FEA method is usually time-consuming, especially for large-scale parts. Herein, multiple 3D FEA
models with simple assumptions on the heat source and its loading methods are compared and
validated with experimental thermocouple data.",,,,,,
"Wilkening, Christian",2018-11-09T16:23:16Z,2018-11-09T16:23:16Z,1996,Mechanical Engineering,doi:10.15781/T22F7K997,http://hdl.handle.net/2152/69930,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['RP-processes', 'DMLS', 'DCP']",Fast Production of Technical Prototypes Using Direct Laser Sintering of Metals and Foundry Sand,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7712620-b7d3-4b1a-baad-f0c17235fd18/download,,"Currently most RP-Parts are used for visualisation, assembly checks and some functional
testing. The next stage between these functional prototypes and the pre-series is technical
prototypes, which are used for final functional testing and optimisation of the production
process. These must not only have the same material as the series parts, but must also be
manufactured with the same production process. Due to the second ofthese requirements layer
manufacturing processes cannot be used to build these prototypes directly, but they can be used
to make the negative moulds or tools.
Two new RP-processes based on laser sintering now have the capability to produce the moulds
and tools via very short and fast process chains. Both have already been in commercial use in
Europe for about one year.
The first process manufactures tools for injection moulding of plastic parts by Direct Metal
Laser Sintering (DMLS). The second process, called the Direct Croning Process (DCP), is used
to build sand moulds and cores for sand casting of metal parts directly from Croning-Sand
without any tools. These technologies have been developed by EOS GmbH, Munich, and are
marketed under the names EOSINT M and EOSINT S respectively",,,,,,
"['Pan, Yayue', 'Chen, Yong', 'Zhou, Chi']",2021-10-06T22:23:34Z,2021-10-06T22:23:34Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88458', 'http://dx.doi.org/10.26153/tsw/15395']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'high-speed fabrication', 'fast recoating', 'stereolithography']",Fast Recoating Methods for the Projection-based Stereolithography Process in Micro- and Macro-Scales,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59cb8899-e4c6-40c2-9a8d-5366b513c21d/download,University of Texas at Austin,"The purpose of this paper is to present a recoating method for the development of a direct digital
manufacturing (DDM) process that can be an order of magnitude faster than other currently available
DDM processes. In the mask-image-projection-based Stereolithography (MIP-SL) process, projection
light controlled by a Digital Micromirror Device (DMD) can quickly cure liquid photopolymer resin in a
whole area; a fast recoating method is required for achieving truly high-speed fabrication. We investigate
the bottom-up projection system in the MIP-SL process. For the macro-scale MIP-SL process, a two-way
linear motion approach has been developed for the quick spreading of liquid resin into uniform thin layers.
In comparison, a direct pull-up motion can be used in the micro-scale MIP-SL process. The system design
and related settings for achieving a fabrication speed of a few seconds per layer are presented.
Additionally, the hardware, software, and material setups for fabricating three-dimensional (3D) digital
models are presented. Experimental studies using the developed testbed have been performed to verify the
effectiveness and efficiency of the presented fast MIP-SL process.",,,,,,
Wales,2018-04-16T17:42:57Z,2018-04-16T17:42:57Z,1991,Mechanical Engineering,doi:10.15781/T21834K30,http://hdl.handle.net/2152/64313,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'CAD systems', 'CAM systems']","Fast, Precise, Safe Prototypes with FDM",Conference paper,https://repositories.lib.utexas.edu//bitstreams/3da99502-25b7-4ab5-a347-6be6150b6116/download,,,,,,,,
"Knirsch, James R.",2020-02-17T15:13:03Z,2020-02-17T15:13:03Z,8/19/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/80007', 'http://dx.doi.org/10.26153/tsw/7032']",eng,2004 International Solid Freeform Fabrication Symposium,Open,rapid production tooling,Faster - Better Molds Through RSP Tooling New Research and Advancements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/970a3a9e-50b5-4031-a608-5814977e92de/download,,"The recent developments in rapid production tooling have all but made the need for
prototype tooling disappear. There are several approaches that are now as fast and
inexpensive as prototype tooling, and after part approval can continue to run in high volume
production applications. The newest of these approaches is an indirect spray forming process
invented by Dr. Kevin McHugh of the Idaho National Engineering and Environmental
Laboratories (INEEL). The advantages of RSP Tooling can be found in its accuracy, finish,
cost and speed compared to the other rapid tooling processes [1].
The commercialization effort for this spray forming process started in February of
2002. The beta production machine was operational in November, 2003, and started to
produce production tooling in March, 2004. Since that time tooling has been manufactured
and run for many forming applications. In all but the simplest tools the process has proven to
be less expensive and faster than standard machining of tools or any other rapid production
tooling process. Research and development of the process has continued both at INEEL and
at RSP Tooling, LLC making the process faster, more accurate and less expensive to operate.
This research has also generated a better understanding of the underlying metallurgy of the
process.",,,,,,
"['Stoffregen, Hanns A.', 'Butterweck, Katja', 'Abele, Eberhard']",2021-10-13T20:34:01Z,2021-10-13T20:34:01Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88779', 'http://dx.doi.org/10.26153/tsw/15713']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['fatigue life', 'selective laser melting', 'thin-walled housings', 'piezoceramic actuators', 'cyclic loads']",Fatigue Analysis in Selective Laser Melting: Review and Investigation of Thin-Walled Actuator Housings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ab0b42f-c561-469a-89be-84e013d9b674/download,University of Texas at Austin,"The versatile applicable selective laser melting (SLM) is a promising manufacturing technology that
allows 3-dimensional design freedom for complex and challenging load bearing parts. A specific application of SLM is the production of thin-walled housings for piezoceramic actuators which induce cyclic loads. Although
there are investigations on the fatigue behavior of SLM-specimens, wide acceptance of SLM is limited by a lack of knowledge concerning the operating behavior of actual parts. This paper presents a review on existing studies about fatigue life analysis in SLM as well as results from uniaxial high cycle fatigue (HCF) tests of 1.4542
stainless steel as-built and machined specimens with a stress ratio of R = 0. Due to a lower surface roughness machined specimens show significantly higher fatigue strength compared to as-built ones. The obtained fatigue strength at 107 cycles of as-built specimens is used as input for fatigue tests of thin-walled actuator housings.
Numerical simulation is used to determine the stress distribution of thin-walled as-built actuator housings under specific loads. Results indicate that the thin-walled as-built actuator housing withstand higher peak stresses compared to as-built specimens due to a high stress gradient.",,,,,,
"['Rajeshirke, Mithila', 'Fidan, Ismail', 'Gupta, Ankit', 'Mäntyjärvi, Kari']",2023-01-20T14:22:44Z,2023-01-20T14:22:44Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117258', 'http://dx.doi.org/10.26153/tsw/44139']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['FRAM', 'Tensile strength', 'Fatigue strength', 'ANOVA', 'Fatigue life']",Fatigue Analysis of Short Carbon Fiber Reinforced Composite Components Manufactured Using Fiber-Reinforced Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/285d2d87-1bc5-4175-84e9-50c0ec911f96/download,,"Fiber-reinforced additive manufacturing (FRAM) has become quite popular in several 
industries. The technology offers an opportunity to improve the existing mechanical performance 
of the part. This research study has presented a successful methodology to fabricate the FRAM-
based composite parts with improved fatigue properties. Most engineering applications are 
subjected to cycling loading which makes the fatigue study an important analysis. The scope of 
this paper is to present the fatigue properties of short carbon fiber-reinforced Polyethylene 
Terephthalate Glycol (SCFs/PETG) of 13.78% by weight. The fatigue behavior was analyzed by 
varying the 3D printing process parameters i.e., infill orientation (0°, 45°, and 90°), and infill layer 
heights (0.2 and 0.3 mm). The tests are carried out on 1600 N as a maximum load of fatigue cycle 
with a 0.1 stress ratio, for the specimens with 90° and 45° orientations with 0.2 and 0.3 mm layer 
heights. For 0° orientation, both 0.2 and 0.3 mm layer height specimens are applied to 2600 N as 
maximum load, keeping the stress ratio the same as 0.1. Analysis of Variance (ANOVA) is used 
to statistically analyze the testing data to understand the influence of input variables on fatigue 
properties.",,,,,,
"['Johnson, Alexander S.', 'Shuai, Shao', 'Shamsaei, Nima', 'Thompson, Scott M.', 'Bian, Linkan']",2021-10-26T20:07:46Z,2021-10-26T20:07:46Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89572,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fatigue', 'failure mechanisms', 'tensile behavior', 'microstructure', 'additive manufacturing', 'superalloys']",Fatigue Behavior and Failure Mechanisms of Direct Laser Deposited Inconel 718,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e07b124-f008-4088-8bda-b5b02de0ab0e/download,University of Texas at Austin,,,,,,,
"['Lee, Seungjong', 'Pegues, Jonathan', 'Shamsaei, Nima']",2021-11-17T23:42:26Z,2021-11-17T23:42:26Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90357', 'http://dx.doi.org/10.26153/tsw/17278']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser beam powder bed fusion', 'LB-PBF', 'surface roughness', 'stainless steel', 'fatigue']",Fatigue Behavior of Additive Manufactured 304L Stainless Steel Including Surface Roughness Effects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0804b9bc-dab5-45cb-9eec-49650e9a096f/download,University of Texas at Austin,"The fatigue behavior of additive manufactured parts in the as-built surface condition is
typically dominated by the surface roughness. However, the fatigue behavior of 304L stainless
steel fabricated by laser beam powder bed fusion shows less sensitivity to surface roughness under
strain-controlled loading conditions than other additive manufactured materials. Under force-controlled conditions, however, the high cycle fatigue resistance is much lower for the as-built
surface condition than the machined one. This study investigates the underlying mechanisms
responsible for fatigue failure for each condition (i.e. strain-controlled or force-controlled). The
corresponding cyclic deformation behavior was characterized, and a thorough fractography
analysis was performed to identify the features responsible for crack initiation. Results indicate
that the crack initiation features in both loading conditions are similar, and that the reduced high
cycle fatigue resistance for force-controlled fatigue loading compared to strain-controlled one is
related to differences in the cyclic deformation behavior of the material.",,,,,,
"['Uhlmann, Eckart', 'Gerlitzky, Georg', 'Fleck, Claudia']",2021-11-02T13:39:54Z,2021-11-02T13:39:54Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89799,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['fatigue life', 'post process', 'process chain', 'metal-based additive manufacturing']",Fatigue Behavior of Additive Manufactured Parts in Different Process Chains - An Experimental Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/54cd37ae-ad55-48db-945d-2829809ecce9/download,University of Texas at Austin,"Metal based Additive Manufacturing (AM) has experienced dynamic growth in recent
years. However, the global distribution of Additive Manufacturing is limited by the fact the
produced parts suffer from bad surface quality and the material properties concerning fatigue life
are still an object of current investigations which limits possible applications of AM parts. Due to
this fact metal AM processes are often followed by a post process to ensure a better surface
quality. In this paper the authors present results where fatigue life and different post processes of
additive manufactured parts are investigated. Subsequently, surface roughness, high cycle
fatigue, fracture behavior and microstructure have been characterized. Finally the results for the
different post processing states have been compared and surface properties as well as
microstructure have been correlated with the fatigue properties in order to evaluate how different
process chains influence the High cycle fatigue (HCF) behavior of additive manufactured parts.",,,,,,
"['Johnson, Alexander S.', 'Shrestha, Rakish', 'Nezhadfar, P.D.', 'Shamsaei, Nima']",2021-11-18T00:38:01Z,2021-11-18T00:38:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90374', 'http://dx.doi.org/10.26153/tsw/17295']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['Inconel 718', 'fatigue', 'elevated temperature', 'laser beam directed energy deposition']",Fatigue Behavior of Laser Beam Directed Energy Deposited Inconel 718 at Elevated Temperature,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fcda701-4f8f-48ff-a746-18e22ac24b1b/download,University of Texas at Austin,"Nickle based super alloys such as Inconel 718 are being extensively used to manufacture
turbine blades for jet engines due to their superior mechanical properties at higher working
temperatures. Furthermore, poor machinability associated with Inconel 718 also makes it an
attractive material for additive manufacturing processes, which possess the capability to fabricate
near net shaped parts. Hence, in this study, the fatigue behavior of Inconel 718 fabricated using
laser beam directed energy deposition (LB-DED) is investigated under strain-controlled, fully-reversed conditions at an elevated temperature of 650° C. Fractography analysis was conducted to
determine the failure mechanism for additive manufactured Inconel 718 due to higher working
temperatures. The results obtained from the fatigue and fractography analysis were then compared
with the results obtained from fatigue tests conducted at room temperature. At elevated test
temperature, LB-DED Inconel 718 specimens exhibited lower fatigue resistance compared to the
tests conducted at the room temperature, primarily in the low cycle fatigue regime. Whereas, in
the high cycle fatigue regime the effect of test temperature was observed to be minimal.
Furthermore, secondary cracks resulting from the formation of brittle behaving precipitates on the
grain boundaries was also evident from the fractography analysis indicating significant changes in
the microstructural features of LB-DED Inconel 718 as a consequence of elevated test temperature.",,,,,,
"['Carrion, Patricio', 'Shamsaei, Nima']",2021-11-18T00:58:47Z,2021-11-18T00:58:47Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90381', 'http://dx.doi.org/10.26153/tsw/17302']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'mean stress', 'variable amplitude', ""miner's rule"", 'titanium']",Fatigue Behavior of LB-PBF Ti-6Al-4V Parts Under Mean Stress and Variable Amplitude Loading Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44d53d03-ea13-46b4-9642-a74e24622f69/download,University of Texas at Austin,"Additively manufactured components are intended for use in load bearing applications,
which are often accompanied by fluctuating external loadings. Therefore, understanding the
fatigue behavior of AM materials under variable amplitude loadings is necessary for ensuring
reliable in-service component performance. This research focuses on the fatigue behavior of Ti-6Al-4V, fabricated via laser beam powder bed fusion process, under mean stress and variable
amplitude loadings. Mean stress effects are investigated under strain-controlled constant amplitude
loading under fully-reversed, Rε = -1, and tension-release, Rε = 0, strain ratios. The generated data
is used to compare two mean stress models including Morrow and Smith-Watson-Topper. Variable
amplitude loading conditions include fully reversed high-low and low-high loading to investigate
load sequence and history effects. Finally, cumulative fatigue damage and life predictions are made
using the linear damage accumulation model (i.e., Miner’s rule).",,,,,,
"['Yadollahi, Aref', 'Shamsaei, Nima', 'Thompson, Scott M.', 'Elwany, Alaa', 'Bian, Linkan', 'Mahmoudi, Mohamad']",2021-10-20T22:02:17Z,2021-10-20T22:02:17Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89373,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', '17-4PH stainless steel', 'fatigue behavior', 'tensile properties']",Fatigue Behavior of Selective Laser Melted 17-4 PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7759ce43-d354-42ad-8d58-61da5b0fe719/download,University of Texas at Austin,"In this investigation, fully-reversed strain-controlled fatigue tests were conducted on
Selective Laser Melted (SLM) 17-4 PH stainless steel (SS). Cylindrical 17-4 PH rods were
fabricated vertically-upward using optimized process parameters to ensure a dense product. Post-fabrication heat treatments (solution annealing and aging) were applied on half of the as-built
samples. Fatigue behavior and tensile properties of the as-built and heat treated samples were
investigated and compared with available data from the literature. The microstructure analysis
and fractography were performed to discern the failure initiation sites, crack propagation path,
and fracture surface morphology. Fatigue lives of SLM 17-4 PH SS specimens were found to be
significantly shorter than their wrought counterparts. It was also found that heat treatment
hardens the SLM 17-4 PH SS specimens while also shortens their fatigue life in the high cycle
regime. The presence of defects, which serve as crack initiation sites, and more sensitivity of
heat treated specimens to impurities, due to higher hardness, were the main reasons for these
observations.",,,,,,
"['Moore, Jacob P.', 'Williams, Christopher B.']",2021-10-06T21:03:53Z,2021-10-06T21:03:53Z,8/20/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88442', 'http://dx.doi.org/10.26153/tsw/15379']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['direct 3D printing', 'Objet PolyJet', 'elastomer', 'fatigue']",Fatigue Characterization of 3D Printed Elastomer Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fdb60f4-bafe-4c3c-8e90-72f3fd350821/download,University of Texas at Austin,"The Objet PolyJet 3D Printing process provides the ability to print graded materials featuring
both stiff and elastomeric polymers. This capability allows for a variety of new design
possibilities for additive manufacturing such as living hinges, shock absorbing casings, and
integrated gaskets. Such design features typically rely upon the ability of traditional elastomers
to experience large and repeated strains without permanent deformation or damage. However,
voids and other flaws inherent to many Additive Manufacturing (AM) processes can have a
significant negative impact on the fatigue life of elastomeric AM materials. In this paper, the
authors seek to fill a gap in the literature by characterizing the fatigue life of a direct 3D printed
elastomer, and the multi-material interface. Based on the results, the authors offer advice for
improving fatigue life of printed elastomeric components.",,,,,,
"['Wolcott, P.J.', 'Dapino, M.J.']",2021-10-05T19:57:23Z,2021-10-05T19:57:23Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88422', 'http://dx.doi.org/10.26153/tsw/15361']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic additive manufacturing', 'aluminum 3003 H-18', 'tensile fatigue', 'bond failure']",Fatigue Characterization of Ultrasonic Additive Manufactured Aluminum 3003,Conference paper,https://repositories.lib.utexas.edu//bitstreams/494db52f-16cb-4297-8fd1-5fdbde944506/download,University of Texas at Austin,"An aluminum 3003 H-18 block was built using ultrasonic additive manufacturing with
process parameters which optimize mechanical strength. Transverse tensile fatigue tests were
conducted on samples cut from the block and a stress vs. number of cycles curve was generated.
Results show the curve is relatively flat and a stress threshold of 50% of the ultimate transverse
tensile strength exists below which failure does not occur within 3.75 × 107
cycles. Optical and
scanning electron microscopy conducted on failure surfaces shows no signs of crack initiation or
growth typical of fatigue loading, but exhibits areas of no bonding between foil layers. To
explain the failure, a model was developed based on the probabilistic failure of bonded areas in
tension. The model uses a Frechet distribution to describe the probability of failure at each
individual bonded area. Discrete bond failure and subsequent redistribution of stress to the
surviving areas eventually leads to failure for the entire sample. Predictions from the model
show good correlation with the experimental results.",,,,,,
"['Banuelos, C.', 'Ramirez, B.', 'De la Cruz, A.', 'Nabil, S.T.', 'Arrieta, E.G.', 'Wicker, R.B.', 'Medina, F.']",2024-03-27T15:39:16Z,2024-03-27T15:39:16Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124484', 'https://doi.org/10.26153/tsw/51092']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'flexural stress', 'fatigue endurance', 'additive manufacturing', 'post-processed parts']",Fatigue Endurance Investigation of Post-processed Surfaces of LPBF Ti-6Al-4V under Flexural Stress,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e35cf89-7e91-42c7-bb7d-a9473d360952/download,University of Texas at Austin,"Numerous research works can be found focusing on fatigue properties of AM components,
however most of this literature is focused on uniaxial testing. Because the very few actual
components under uniaxial loading conditions found in any application, it is also important to
investigate fatigue performance under loads that produce combined stresses, such as bending. This
project investigates the fatigue endurance of LPBF Ti-6Al-4V specimens subjected to four
different surface finishing prost-processes (milled, ground, polished and abrasive media). The test
consisted of a force-controlled cyclic load applied on the specimen in a 4-point bending setup until
fracture. The study incorporated mechanical and optical techniques to measure and quantify the
characteristic surface roughness of the post-processes. Additionally, failure mechanisms are
discussed on fractographs. The data analyses suggested that internal defects commonly present in
additively manufactured parts had a more significant impact on the fatigue life than surface
roughness of post-processed parts.",,,,,,
"['Muhammad, Muztahid', 'Carrion, Patricio E.', 'Shamsaei, Nima']",2021-11-18T00:14:56Z,2021-11-18T00:14:56Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90366', 'http://dx.doi.org/10.26153/tsw/17287']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'defect size', 'NASGRO', 'fatigue life prediction']",Fatigue Life Prediction of Additive Manufactured Materials Using a Defect Sensitive Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5f03c739-314e-4362-8319-8045ff47a0a1/download,University of Texas at Austin,"This study utilized a defect sensitive fatigue model based on a fracture mechanics concept
to predict the fatigue life of 17-4 precipitation hardening (PH) stainless steel (SS) fabricated using
laser beam powder bed fusion (LB-PBF) process. Size of defects such as gas entrapped pores are
captured using fractography analysis and calculated employing Murakami’s approach with the
√area method. Considering the value of the √area as initial crack length, fatigue life is then
calculated using NASGRO software, and compared to the experimental data obtained from strain-controlled fatigue testing. A comparison between predicted fatigue lives using NASGRO software,
combined with the Murakami approach, and experimentally obtained ones were presented to
determine the applicability of the utilized model for predicting the fatigue performance of additive
manufactured materials.",,,,,,
"['Torries, Brian', 'Shrestha, Rakish', 'Imandoust, Aidin', 'Shamsaei, Nima']",2021-11-10T22:41:22Z,2021-11-10T22:41:22Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90196', 'http://dx.doi.org/10.26153/tsw/17117']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'defects', 'fracture mechanics', 'fatigue modeling']",Fatigue Life Prediction of Additively Manufactured Metallic Materials Using a Fracture Mechanics Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa317e2b-332f-4914-b109-1ce9bf808c8e/download,University of Texas at Austin,"The present study aims to model the fatigue strength of additively manufactured metallic
materials employing a fracture mechanics approach. Specimens with different build orientations
were subjected to strain controlled fatigue testing. Upon failure, the defect(s) responsible for crack
initiation were identified by fractographic analysis. From these defects an equivalent internal
defect size is calculated using the √𝑎r𝑒𝑎 method based on Murakami model. Using this parameter,
the elastic-plastic energy release rate (𝛥𝐽𝐽𝑒𝑓𝑓) was determined, and the relationship between 𝛥𝐽𝑒𝑓𝑓
and fatigue life was investigated. The results showed that this method improves the predictability
of the fatigue strength of additively manufactured materials when the defects size and location is
known. The 𝛥𝐽𝑒𝑓𝑓 − 𝑁𝑓 relationship appeared to better fit the fatigue data of the experimental
materials as compared to the 𝜀𝑎 − 𝑁𝑓 relationship and contributed to a reduction in data scatter.",,,,,,
"['Alkunte, Suhas', 'Rajeshirke, Mithila', 'Huseynov, Orkhan', 'Fidan, Ismail']",2024-03-25T22:12:46Z,2024-03-25T22:12:46Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124315', 'https://doi.org/10.26153/tsw/50923']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['fatigue life', 'fatigue prediction', ""Basquin's Model"", 'S-N curve', 'FGAM']",Fatigue Life Prediction of Functionally Graded TPU and PLA Components Produced by Material Extrusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f39fb836-c0f7-432b-b6c9-1e37ae7a7fc5/download,University of Texas at Austin,"The objective of the present research is to examine the fatigue life estimation of functionally
graded additive manufacturing (FGAM) components produced by the Material Extrusion (MEX).
Current research studies demonstrate the potential of functionally graded materials (FGMs) in
enhancing the mechanical properties of engineered structures. The raw materials employed for the
experimentation of this study are a combination of Polylactic acid (PLA) and Thermoplastic
Polyurethane (TPU). To predict fatigue life, several researchers have utilized various statistical
approaches. In this investigation, an experimental study is conducted utilizing Tension-Tension
(T-T) loading conditions and different stress levels (80, 60, 40, and 20% of Ultimate tensile
strength), followed by the application of Basquin’s Model for fatigue life prediction. The results
obtained indicate that the model may be utilized to predict fatigue response. Overall, the soft-hard
material combinations with adaptable properties produced through FGAM have potential
applications in dental and orthopedic fields.",,,,,,
"['Maskery, I.', 'Aboulkhair, N.T.', 'Tuck, C.', 'Wildman, R.D.', 'Ashcroft, I.A.', 'Everitt, N.M.', 'Hague, R.J.M.']",2021-10-21T15:31:05Z,2021-10-21T15:31:05Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89397,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'aluminum alloy', 'AlSi10Mg', 'stress-strain', 'fatigue performance']",Fatigue Performance Enhancement of Selectively Laser Melted Aluminum Alloy by Heat Treatment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/60d145ef-ca57-44b9-a051-7e5031161e7c/download,University of Texas at Austin,"We measured the stress-strain behaviour and fatigue performance of the aluminium
alloy Al-Si10-Mg manufactured by selective laser melting (SLM). This process, specifically the rapid cooling of the metal from its molten state, results in a fine microstructure, generally providing high hardness but poor ductility. We used a heat treatment
to alter the microstructure of the material from its as-built state. This significantly
improved the ductility and fatigue performance. The elongation at break for the heat
treated material was nearly three times greater than that observed for the as-built
material, and the fatigue strength at 106
cycles was around 1.6 times as high. Combined with the design freedoms of additive manufacture, this development increases
the suitability of lightweight SLM parts for use in the aerospace and automotive
sectors, where good fatigue performance is essential.",,,,,,
"['Beard, William', 'Lancaster, Robert', 'Adams, Jack', 'Buller, Dane']",2021-11-30T21:02:08Z,2021-11-30T21:02:08Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90547', 'http://dx.doi.org/10.26153/tsw/17466']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser powder bed fusion', 'stainless steel 316L', 'low cycle fatigue']",Fatigue Performance of Additively Manufactured Stainless Steel 316L for Nuclear Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cf0efc07-11af-49f6-ae85-5d40e7edfdf8/download,University of Texas at Austin,"Additive manufacturing (AM) is a rapidly growing technology which is extending its
influence into many industrial sectors such as aerospace, automotive and marine. Recently the
nuclear sector has considered AM in the production of nuclear reactor components due to its
possible advantages over conventional manufacturing routes. This includes considerable cost
savings due to less material wastage, the ability to produce complex near net shape components
that conventional manufacturing processes are unable to achieve and a reduced manufacturing
time. Initially, Stainless Steel 316L (SS316L) manufactured by laser powder bed fusion
(LPBF) has been identified as a potential candidate. However, due to the transient nature of the
microstructure it is now of fundamental importance to assess and understand the mechanical
behaviour of the LPBF material.
This paper will highlight some of the recent research at Swansea University in
investigating the variation on the fatigue characteristics between wrought SS316L and LPBF
processed SS316L material. This will include an extensive microstructural and fractographic
investigation. As LPBF material looks to replace conventionally manufactured equivalents, an
understanding of how build integrity and orientation affects the mechanical properties of AM
material is critical. Wrought and vertical LPBF material are to be assessed to understand how
the microstructure controls the fatigue performance of LPBF SS316L material.",,,,,,
"['Raju, Nandhini', 'Rosen, David W.']",2021-12-06T21:56:06Z,2021-12-06T21:56:06Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90687', 'http://dx.doi.org/10.26153/tsw/17606']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['maraging steel', 'fatigue properties', 'powder bed fusion', '3D printing']",Fatigue Properties of 3D Printed Maraging Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3475c52c-f599-473b-b3cf-da9f056abce5/download,University of Texas at Austin,"The objective of this paper is to investigate fatigue properties of maraging steel, in the
fabricated, machined, and heat-treated conditions, printed by powder bed fusion. Samples were
manufactured in an EOS M280 machine in the X and Z build directions. Manufactured samples
were tested under four different conditions: fabricated, machined, heat-treated, and heat-treated
and machined. Each condition was expected to have different fatigue properties. The maximum
stress and number of cycles to failure results were compared to understand the influence of the
different build orientations and conditions on fatigue properties and limits. Results showed that
machining and heat treatment, individually and together, had significant effects on fatigue
properties. Additionally, the selection of standards, selection of sample counts, and statistical
analysis of results will be discussed along with the maraging steel fatigue properties.",,,,,,
"['Nandi, Indrajit', 'Welsh, Jade', 'Simsiriwong, Jutima', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-25T14:18:50Z,2023-01-25T14:18:50Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117288', 'http://dx.doi.org/10.26153/tsw/44169']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Murakami’s model', 'Laser powder bed fusion', 'Very high cycle fatigue', '17-4  precipitation hardened stainless steel']",Fatigue strength prediction through defects-based analysis of L-PBF 17-4 PH stainless steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dae40d16-6c9d-4a73-8c23-cf0c3569c096/download,,"Murakami’s approach has been used in the high cycle fatigue regime to relate the fatigue 
limit to the critical defect size and location in additively manufactured (AM) metallic materials. 
However, the applicability of this model has not yet been thoroughly examined for AM materials 
in the very high cycle fatigue (VHCF) regime. Therefore, this study investigates the possibility of 
relating the volumetric defect features to the fatigue strength of 17-4 precipitation hardened (PH) 
stainless steel (SS) manufactured via laser-powder bed fusion (L-PBF) additive manufacturing 
technology. The 17-4 PH SS specimens are manufactured using an EOS M290 L-PBF system, 
heat-treated, machined, polished, and tested in the VHCF regime using an ultrasonic fatigue testing 
system. Careful fractography has also been performed on all fractured specimens to determine the 
volumetric defects responsible for the crack initiation.",,,,,,
"['Blake, Paul', 'Fodran, Eric', 'Koch, Martin', 'Menon, Unny', 'Priedeman, Bill', 'Sharp, Stephen']",2018-11-29T20:48:37Z,2018-11-29T20:48:37Z,1997,Mechanical Engineering,doi:10.15781/T20863R44,http://hdl.handle.net/2152/70342,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD/CAM', 'Acrylinitrile']",FDM of ABS Patterns for Investment Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/886b8233-e841-48a3-b9f8-fe82042fc79e/download,,"This paper will evaluate the suitability offused deposition modeling (FDM) of
acrylonitrile butadiene styrene (ABS) patterns for use in investment casting. The focus is
on integration with existing foundry practices. It is a combined industry/university
project with the case studies performed at the industrial sites with university produced
patterns. Process parameters, ash handling and casting issues are addressed.",,,,,,
"['Tyberg, Justin', 'Bohn, Jan HeIge']",2019-02-22T20:07:12Z,2019-02-22T20:07:12Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73472', 'http://dx.doi.org/10.26153/tsw/622']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['slicing techniques', 'smooth-surface']",FDM Systems and Local Adaptive Slicing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7d59c69e-76f9-435e-933a-2cca3358d330/download,,,,,,,,
"['Comb, James', 'Priedeman, William', 'Turley, Patrick W.']",2018-09-26T19:33:12Z,2018-09-26T19:33:12Z,1994,Mechanical Engineering,doi:10.15781/T25X25Z09,http://hdl.handle.net/2152/68588,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'deposition geometry', 'fused modeling process']",FDM® Technology Process Improvements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e34f58b0-2a7e-44b8-b992-6fc940ea3081/download,,"Since the introduction ofrapid prototyping technology as a tool for time compression and concurrent engineering in
the design and manufacturing process, many enhancements and refinements have been made based on the experience
of users and manufacturers of rapid prototyping equipment. These improvements contribute significantly to faster
production of quality output from rapid prototyping systems.
There are diverse control and material selection parameters that affect prototype models built using the Fused
Deposition Modeling (FDM®) process. This paper reviews the role of several of these parameters in the process.
Data will be presented to help the user choose the appropriate material for specific applications including density,
tensile modulus, flexural modulus, tensile strength, flexural strength, impact strength, and hardness.
The integration of material, hardware, and software in the FDM technology begins with the understanding of the
basic requirements ofthe machine and ends with an operating procedure to choose the parameters for optimal model
output and efficiency. Some of the variables include: part geometry, deposition geometry, deposition speed,
liquefier temperature, material, flow control parameters, etc. Designed experiments are used in material formulation
through modeling parameter defmition activities",,,,,,
"['Reiher, Thomas', 'Koch, Rainer']",2021-10-21T16:55:13Z,2021-10-21T16:55:13Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89404,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'FE-optimization', 'topology optimization', 'structural parts']",FE-Optimization and Data Handling for Additive Manufacturing of Structural Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f27cb4cd-8ada-4415-ac2c-815bb07d4110/download,University of Texas at Austin,"Additive Manufacturing (AM) offers high potential due to its freedom of design for
structural parts. Especially in combination with FE-based topology optimization an optimal
use of material and thus significant weight reductions can be expected. However, the
application of AM is hampered by different additional manufacturing processes along the
entire production chain and data handling induced restrictions.
Disadvantages emerge from a lack of adjustment of the entire design process for AM. First
the optimization algorithms are not targeted to the opportunities and restrictions of AM –
represented by design rules – like the design of support structures. Secondly, the CAD
software is not adjusted to AM in particular. Creating freeform shaped surfaces based on the
optimization results is significantly less convenient than building defined blocks or turning
parts following the needs of conventional machining. The indispensable subsequent
interpretation of optimization results regarding the design rules and the possibilities of CAD-tools counteracts optimal results.
This paper considers different approaches for a Topology Optimization (TO)-shape
regaining on different sample parts including telecommunication satellite parts. An innovative
design methodology is presented getting crucial for creating high quality designs.",,,,,,
"['Masuo, Christopher', 'Nycz, Andrzej', 'Noakes, Mark W.', 'Vaughan, Derek', 'Sridharan, Niyanth']",2021-11-18T01:09:58Z,2021-11-18T01:09:58Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90385', 'http://dx.doi.org/10.26153/tsw/17306']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'maraging steel', 'high-strength tooling', 'feasibility', 'single bead welds', 'metal big area additive manufacturing', 'mBAAM']",Feasibility Analysis of Utilizing Maraging Steel in a Wire Arc Additive Process for High-Strength Tooling Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61b79a38-98c1-429c-92f3-4c42b5ed1443/download,University of Texas at Austin,"Traditional tool and die development require skilled labor, long lead time, and is highly
expensive to produce. Metal Big Area Additive Manufacturing (mBAAM) is a wire-arc additive
process that utilizes a metal inert gas (MIG) welding robot to print large-scale parts layer-by-layer.
By using mBAAM, tooling can be manufactured rapidly with low costs. For cold work tooling
applications, a high hardness level is desired to increase the life-time of the tool. A promising
material that can achieve this is maraging steel. Maraging steel is known to have good weldability;
however, further testing must be conducted to ensure it is feasible for printing using mBAAM. In
this paper, initial process parameters were obtained by printing single bead welds. Multi-bead
walls were then printed with some refinement of process parameters to construct homogenous
outer features of the walls. Lastly, the walls were heat-treated, and hardness data was gathered
through Rockwell Hardness tests.",,,,,,
"['Wu, Guohua', 'Langrana, Noshir', 'Rangarajan, Sriram', 'Sadangi, Rajendra', 'Safari, Amhad', 'Danforth, Stephen C.']",2019-02-26T16:56:37Z,2019-02-26T16:56:37Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73486', 'http://dx.doi.org/10.26153/tsw/636']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'RTV mold']",Feasibility of Fabricating Metal Parts from 17-4PH Stainless Steel Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/96e22285-2ffc-4ad6-a985-84046e9907b4/download,,"17-4 PH stainless steel is known to provide an attractive combination of high strength and
corrosion resistance. In this research, the feasibility of SFF fabrication of high density parts using
PH powder is examined. A part can be fabricated using both indirect and direct methods.
The indirect method includes making a negative RTV mold, making compounded material using
ECG binder and stearic acid with the metal powder, and pouring the compounded material to get
a green part. This is followed by binder bum out(BBO) and sintering cycles. The direct method
uses Fused Deposition of Metals(FDMet). In FDMet, the 17-4PH powder is compounded with a
binder and extruded into filaments, followed by part building, BBO and sintering. The initial
results of the indirect method of fabrication produced 91 % theoretical density of 17-4 PH parts
with Vickers hardness of 223",,,,,,
"['Jonckers, D.', 'Tauscher, O.', 'Stoll, E.', 'Thakur, A.']",2021-12-07T18:12:33Z,2021-12-07T18:12:33Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90744', 'http://dx.doi.org/10.26153/tsw/17663']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['feasibility', 'on-orbit additive manufacturing', 'large-scale freeforming', '3D printing']","Feasibility Study of Large-Format, Freeform 3D Printing for On-Orbit Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b3cf0d04-1cce-4f05-9126-d302b3e441a7/download,University of Texas at Austin,"Large scale, on-orbit additive manufacturing (AM) and assembly is being considered as a
modular and resource saving approach to facilitate permanent human presence in space. To realise
this, a novel AM approach to freeform fabricate large, functional structures in space has been
developed. Combining the reach of a free-flying CubeSat with a collaborative robotic arm and a 3D
printer, large support-free thermoplastic structures can be manufactured beyond the size of the setup
itself. The feasibility of the proposed fabrication approach was established using the Experimental
Lab for Proximity Operations and Space Situational Awareness (ELISSA) system, where a modified
fused filament fabrication setup was mounted on a free-flyer to 3D print free-standing structures.
Using a continuous navigation path incorporating an infinite fabrication loop, over 70 centimetre
long, support-free trusses were produced to well demonstrate the potential of the proposed method
in boundless direct printing of complex structures, independent of gravity or printing orientation.",,,,,,
"['Yamagata, Y.', 'Sagawa, T.', 'Nitawaki, M.', 'Abe, T.']",2023-04-03T17:39:49Z,2023-04-03T17:39:49Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117726', 'http://dx.doi.org/10.26153/tsw/44605']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Feasibility Study of Large-Sized Aluminum Facades by Using Wire Arc Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1015a1a7-9e25-45b8-9d85-7bb15b26866f/download,,"Over the past few years, there has been growing interest in the fabrication of construction components by 
using wire arc additive manufacturing (WAAM). We focused on the finishing materials as a potential application 
for WAAM and began to consider fabricating aluminum building facades. However, there are several issues, such 
as fabrication size of 4-5m, aesthetics, and structural performance. Therefore, a trial fabrication and a non-
destructive static loading test were conducted. In the study, an aluminum chair was used as a model because it 
contains the engineering basis of the building facades. In the trial fabrication, a method of leveling the build 
surface for each of the multiple layers was found to be effective for large-sized fabrication. Bead blasting was 
also effective in removing oxides from aluminum surfaces and adjusting the appearance. In the loading test, both 
displacement and strain measurements agreed well with the FEM analytical values. The results showed that 
WAAM has the possibility of fabricating large-sized aluminum building facades with the structural performance 
expected in the FEM analysis.",,,,,,
"['Cunico, Marlon Wesley Machado', 'de Carvalho, Jonas']",2021-10-21T20:34:37Z,2021-10-21T20:34:37Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89440,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'medium scale projection', 'network production', 'flexible manufacturing systems']",Feasibility Study of Small Scale Production Based on Additive Manufacturing Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b10e15b1-f590-476a-8191-ceeabc039d81/download,University of Texas at Austin,"Along the last years, the complexity of products has been growing progressively, while the product development life-cycle tended to be reduced. In addition to that, additive manufacturing technologies increased their role in the product
development process, resulting in reduction of errors and products release time. In spite of these benefits, the main
application of these technologies is still focused on initial phases of projects and results in high costs of parts and low
volumes. On the other hand, although conventional productivity processes results in low costs and high volumes, the
investment related to these processes are high and the implementation time are long. For that reason, the main goal of
this work is to investigate the possibility of application of additive manufacturing technologies for small and medium
scale production. Along this work, the main direct and indirect processes which are used for small and medium scale
production were studied and a numerical cost model were developed for each one. In order to compare the benefits
and disadvantages among the processes, 3 parts were selected and analysed through such models. By the end, the main
cost, payback; amortization and takt time were identified and the most suitable process was found in accordance with
annual part demand.",,,,,,
"['Niino, Toshiki', 'Haraguchi, Hisashi', 'Itagaki, Yutaro']",2021-10-04T20:14:18Z,2021-10-04T20:14:18Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88335', 'http://dx.doi.org/10.26153/tsw/15274']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['plastic laser sintering', 'powder bed heating', 'powder bed preheating', 'energy consumption']",Feasibility Study on Plastic Laser Sintering without Powder Bed Preheating,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13320ce2-98ac-43c6-8149-48d73e04d9e4/download,University of Texas at Austin,"In a plastic laser sintering machine, the most part of power consumption is spent on
heating of powder bed. The powder bed heating is essential to prevent parts from
warping during the process. However metal laser melting is normally performed
without such heating. During the process, warping is suppressed by fixing the parts to a
base plate. In the present research, the same scheme was introduced to plastic laser
sintering. A plate of 2mm was successfully obtained. Residual stress was completely
relieved by annealing treatment of 30min and permanent deformation was negligible. A
relative density of 90%, which is standard level of commercially available part, was
obtained. Tensile and impact strength were limited to 1/2 and 2/3 of those obtained by
normal process, respectively. Energy consumption of laser module in preheating free
process is around 45MJ/kg, and complete robustness against power supply interruption
was demonstrated.",,,,,,
"['Tata, Kamesh', 'Fadel, Georges']",2018-11-16T16:22:39Z,2018-11-16T16:22:39Z,1996,Mechanical Engineering,doi:10.15781/T2959CT47,http://hdl.handle.net/2152/70294,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['3D systems', 'STL model representation', 'CAD']",Feature Extraction From Tessellated And Sliced Data in Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c4a1164-a593-4afd-b38e-ce96111610a4/download,,"When parts are built in layers, the cross sectional area of each layer has to be defined
and filled with a pattern of vectors. This filling process is called hatching and the
vectors defme the hatch pattern. To accurately reproduce a three dimensional object,
key features need to be identified. In particular, top and bottom surfaces, edges. holes
and protrusions must be recognized to ensure the slice plane does carry-the critical information
required for the build. This paper describes a technique to extract relevant
features from a tessellated model to generate a correct sliced representation.",,,,,,
"['Qian, Xiaoping', 'Dutta, Debasish']",2019-03-01T17:30:58Z,2019-03-01T17:30:58Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73515', 'http://dx.doi.org/10.26153/tsw/665']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LM', 'conductivity']",Features in Layered Manufacturing of Heterogeneous Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d490a248-d8b7-4fe4-9e39-6fe7f262caf4/download,,"The usage of features in computer aided design and manufacturing has increased significantly
over the last decade. By and large, all such features are geometric (form features).
In this paper, we shall discuss the need to go beyond current geometric features and consider
material -- composition, and gradation -- within the object. This need has been brought about by
layered manufacturing technologies which build up parts, layer by layer, under computer control.
While industrial use of this new technology has been for making prototypes, functional metallic
parts can/are being made by layered manufacturing. Furthermore, a variety of materials can be
deposited to create multi-material and functionally graded components.
We consider features in this new domain (of layered manufacturing) and identify research topics and present an overview of our current focus on ""material features"" in the context of heterogeneous solid models.",,,,,,
"['Abdelrarhman, Mostafa', 'Starr, Thomas L.']",2021-10-20T20:23:35Z,2021-10-20T20:23:35Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89353,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['polymer laser sintering', 'feed-forward control', 'part geometry', 'temperature history']",Feedforward Control for Polymer Laser Sintering Process Using Part Geometry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19f38e5b-64f6-445d-9e30-42fbd05b62cc/download,University of Texas at Austin,"For the polymer laser sintering process, achieving optimum mechanical properties requires
that every volume element of a part experience a temperature history sufficient to reach full
density. This history must include a peak temperature high enough to fully melt, but not degrade,
the polymer and a cool-down period that ensures elimination of porosity, interlayer bonding and
relaxation of stress. Real-time thermal monitoring of the laser sintering process has shown that this
temperature history depends on the geometries of both the current and prior layers. In this paper
we demonstrate a feed-forward control system that improves uniformity of the temperature history
for parts with variable cross-sections. The control algorithm for this system will utilize information
from layerwise geometry models for parts in a multi-part build. The cross-sectional area for every
layer will be used at run-time for feed forward control the laser scan parameters. The results
confirmed maintaining constant peak temperature throughout the part. This control system ensures
optimized sintering for parts with complex geometries.",,,,,,
"O'Reilly, Sean B.",2018-05-03T18:34:09Z,2018-05-03T18:34:09Z,1993,Mechanical Engineering,doi:10.15781/T2PV6BQ73,http://hdl.handle.net/2152/65055,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['FFF lab', 'Alpha Manufacturing Development Center', '3D Solid Model', 'stereolithography']",FFF at Ford Motor Company,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac3c8f59-cc5a-4831-815e-cccad71f56e2/download,,"Ford's effort in Free Fonn Fabrication (FFF) began in 1987
with the fontation of an internal consortium, Calp)sed of a dozen different
activities, whose purpose was to evaluate and apply, where possible, this
errerging tecl:mology. Each of the consortium members agreed to contribute
sare rroney and, rrore irrportantly, one or rrore people to work on this
project. By the following year (1988) the first rrachine, an SLA-1, had been
installed at the Alpha Msmufacturing Develq:ment Center and fomed the
cornerstone of the FFF Lab.",,,,,,
"['Xia, B.', 'Saari, M.', 'Cox, B.', 'Richer, E.', 'Krueger, P.S.', 'Cohen, A.L.']",2021-10-28T19:35:20Z,2021-10-28T19:35:20Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89678,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['Fiber Encapsulation Additive Manufacturing', 'electrical junctions', 'material fabrication']",Fiber Encapsulation Additive Manufacturing: Materials for Electrical Junction Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de90e005-8c70-4da9-a523-c8bfb1c189cd/download,University of Texas at Austin,"Fiber Encapsulation Additive Manufacturing (FEAM) is a novel 3-D printing process that permits
the printing of electromechanical and electronic devices within a single, affordable machine. A
key challenge of FEAM is creating robust and reliable electrical junctions between encapsulated
wires, enabling more complex devices and circuits to be fabricated. We present current efforts to
explore and characterize several different methods for creating junctions: solder, solder paste, and
a custom-formulated electrically conductive polymer composite. All three methods are analyzed
in terms of printability, material compatibility, repeatability, and performance.",,,,,,
"['Wang, Xin', 'Tian, Xiaoyong', 'Li, Dichen']",2021-11-15T22:14:32Z,2021-11-15T22:14:32Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90290', 'http://dx.doi.org/10.26153/tsw/17211']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['metal matrix composite', '3D printing', 'additive manufacturing']",Fiber Traction Printing--A Novel Additive Manufacturing Process of Continuous Fiber Reinforced Metal Matrix Composite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/55eb840c-a3d6-41ab-8fd6-1bb19116bc0a/download,University of Texas at Austin,"Metal matrix composites (MMCs) are materials which have been widely used in the aerospace and
automobile industries since the 1980s and have been classified as hard-to machine materials. This manuscript
proposes a novel additive manufacturing process of continuous fiber reinforced metal matrix composite -- fiber
traction printing (FTP). The composites with complex structures can be directly manufactured via FTP which
utilizes the wetting force and capillarity force to control the flow of melting matrix. The craft is proceeding
without extra pressure device and atmosphere protection device and substantially decreases the cost. This
manuscript introduces the proof-of-concept prototype and the ability to control the flow of melting matrix and
fiber distribution through this process yields a flexible manufacturing route to fabricating 3D metal matrix
composite parts with full density and complex geometries.",,,,,,
"['Hostetler, John M.', 'Goldstein, Jonathan T.', 'Bristow, Douglas', 'Landers, Robert', 'Kinzel, Edward C.']",2021-11-04T14:18:14Z,2021-11-04T14:18:14Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89967,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['glass fiber', 'transparent glass', 'fiber-fed process', 'laser-heated process', '3D printing', 'additive manufacturing']",Fiber-Fed Laser-Heated Process for Printing Transparent Glass,Conference paper,https://repositories.lib.utexas.edu//bitstreams/51fe27f9-7d60-4bb4-b79c-6f368016c9d2/download,University of Texas at Austin,"This paper presents the Additive Manufacturing (AM) of glass using a fiber-fed process.
Glass fiber with a diameter of 100 μm is fed into a laser generated melt pool. A CO2 laser beam
is focused on the intersection between the fiber and the work piece which is positioned on a four-axis computer controlled stage. The laser energy at λ=10.6 μm is directly absorbed by the silica
and locally heats the glass above the working point. By carefully controlling the laser power,
scan speed, and feed rate, bubble free shapes can be deposited including trusses and basic lenses.
Issues unique to the process are discussed, including the thermal breakdown of the glass,
buckling of the fiber against an inadequately heated stiff molten region, and dimensional control
when depositing viscous material.",,,,,,
"['Hostetler, John M.', 'Johnson, Jason E.', 'Goldstein, Jonathan T.', 'Bristow, Douglas', 'Landers, Robert', 'Kinzel, Edward C.']",2021-11-10T21:25:06Z,2021-11-10T21:25:06Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90180', 'http://dx.doi.org/10.26153/tsw/17101']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['glass fiber', 'glass structure', 'printing', 'additive manufacturing']",Fiber-Fed Printing of Free-Form Free-Standing Glass Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7419e91-76f3-4873-9de9-cff9bcf2332b/download,University of Texas at Austin,"Additive Manufacturing (AM) of low-profile 2.5D glass structures has been demonstrated using
a fiber-fed laser-heated process. In this process, glass fibers with diameters 90-125 µm are
supported as they are fed into the intersection of the workpiece and a CO2 laser beam. The
workpiece is positioned by a four-axis CNC stage with coordinated rotational/transitional
kinematics. The laser energy at λ = 10.6 µm is coupled to phonon modes in the glass, locally
heating it above its working point. The rapid heating and cooling process allows for the
deposition of various glasses into free-standing three-dimensional structures such as trusses and
other complex geometries. Issues unique to the process are discussed, including the thermal
breakdown of the glass and index inhomogeneity between the fiber core and cladding when
using single-mode optical fiber feedstock.",,,,,,
"['Angenoorth, J.', 'Rumschottel, D.', 'Leitner, B.', 'Schumm, V.', 'Ettemeyer, F.', 'Unsal, I.', 'Gunther, D.']",2024-03-27T03:14:06Z,2024-03-27T03:14:06Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124459', 'https://doi.org/10.26153/tsw/51067']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['reinforced sand', 'binder jetting', '3D printing', 'additive manufacturing']",Fiber-Reinforcement of Binder-Jetted Casting Molds for Multiple Usag,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d5923ff4-5302-4e91-b033-c990c0ef22f1/download,University of Texas at Austin,"Widely used sand casting with lost molds is an efficient and cost-effective way of producing geometrically
complex components. As the demand for sand has tripled over the last two decades, finding new solutions for
thermostable binder systems and ensuring the efficient use of resources is essential. To address this issue, the
REINFORCED SAND project is exploring glass fiber-reinforced sand molds and temperature-stable inorganic
binders within the binder-jetting process. The aim is to improve the mechanical properties of the  D-printed
casting molds to make multiple uses of these possible, reducing resource consumption and increasing profitability.
For this purpose, various material systems and manufacturing parameters were examined. It has been
demonstrated that fiber-reinforced sand molds can be used for multiple castings, and fibers can be principally
processed in the binder jetting process. These efforts aim to make sand casting production more environmentally
friendly and sustainable. The REINFORCED SAND project is a step towards achieving these goals.",,,,,,
"['Chesser, Phillip C.', 'Post, Brian K.', 'Roschli, Alex', 'Lind, Randall F.', 'Boulger, Alex M.', 'Love, Lonnie J.', 'Gaul, Katherine T.']",2021-11-15T21:27:50Z,2021-11-15T21:27:50Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90279', 'http://dx.doi.org/10.26153/tsw/17200']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['fieldable platform', 'concrete structure', 'large-scale deposition', 'sky big area additive manufacturing', 'SkyBAAM']",Fieldable Platform for Large-Scale Deposition of Concrete Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/60b25c19-7f43-4dd1-a8fb-027c072fd44f/download,University of Texas at Austin,"Oak Ridge National Laboratory’s Manufacturing Demonstration Facility is developing
a novel, large-scale additive manufacturing, or 3D printing, system. The Sky Big Area Additive
Manufacturing (SkyBAAM) system will ultimately be a fieldable concrete deposition machine
with pick and place abilities that will allow for full-scale, automated construction of buildings.
The system will be implemented with existing construction equipment meaning conventional
cranes will be used to suspend the print head. SkyBAAM will be cable-driven by four base
stations and suspended from a single crane. The elimination of a gantry system, found
commonly in large-scale additive manufacturing systems, will enable SkyBAAM to be quickly
set up with minimal site preparation. The medium-scale version of SkyBAAM is currently in
development. The system design, cable stiffness analysis, and tactics for freezing rotational
degrees-of-freedom (DOF), detailed in this paper, will provide a basis for the final, large-scale
version of the SkyBAAM system.",,,,,,
"['Agarwala, M.K.', 'Weeren, R. van', 'Bandyopadhyay, A.', 'Safari, A.', 'Danforth, S.C.', 'Priedeman, W.R.']",2018-11-15T20:31:27Z,2018-11-15T20:31:27Z,1996,Mechanical Engineering,doi:10.15781/T2GX45D8J,http://hdl.handle.net/2152/70277,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'powder systems', 'binder chemistry']",Filament Feed Materials for Fused Deposition Processing of Ceramics and Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/37e144f9-ec03-41ee-a0e8-ba8e2dd28403/download,,"Fused Deposition of Ceramics (FDC) and Metals (FDMet) are SFF techniques, based on
commercial FDMTM technology, for fabrication of ceramic and metal components. The FD
processes use feed material in the form of filaments which require certain phy~ical and mechanical
properties. FDC and FDMet processes employ fila.n::ents formed from ?erannc ~r metal powders
mixed with thermoplastic polymers. The thermoplastic polymers act as bmder dunng the FDC and
FDMet processing in forming a green part. Development of green ceramic or metal fIlaments for
FDC or FDMet processing involves three critical steps : selection of an appropriate binder
chemistry, appropriate mixing procedures and fIlament fabrication techniques. This study
describes the properties required for filaments for successful FD processing and the approach taken
in the development of a series of binder which meets these requisite properties for a wide range of
ceramics and metals. Appropriate mixing and filament forming techniques are also discussed.",,,,,,
"['Mulholland, T.', 'Falke, A.', 'Rudolph, N.']",2021-10-27T22:52:06Z,2021-10-27T22:52:06Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89639,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'FFF', 'thermal conductivity']",Filled Thermoconductive Plastics for Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/42bbe9eb-09b4-4b11-b151-fff760d4e86a/download,University of Texas at Austin,"Although thermoplastics have traditionally been ignored as heat transfer materials, filled
thermally conductive plastics fabricated in complex geometries can serve as low-cost,
geometrically complicated heat exchangers, along with other thermal applications such as heat
sinks. Thermally conductive, 3D printed heat exchangers can have a significant impact on power
generation technology at many scales, with advantages in allowing distributed, on-site
manufacturing on multiple, independent machines, and the virtual elimination of scrap. This can
command significant cost savings compared to traditional, machined metal heat exchangers. This
work examines compounds of polyamide 6 with copper fiber and sphere fillers produced in a corotating twin screw extruder. The thermal conductivity is measured and related to the filler
content, shape, and orientation.",,,,,,
"['Jariwala, Amit S.', 'Ding, Fei', 'Zhao, Xiayun', 'Rosen, David W.']",2020-03-11T15:10:39Z,2020-03-11T15:10:39Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80247', 'http://dx.doi.org/10.26153/tsw/7266']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Mask Projection Micro-Stereolithography', 'MPµSLA']",A Film Fabrication Process on Transparent Substrate using Mask Projection Micro-Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85303b7b-1ba1-490b-8b94-93d944490617/download,,"In this study, a Mask Projection Micro-Stereolithography (MPµSLA) process with the
ability to cure a film of various thicknesses on transparent substrates is presented. Incident
radiation, patterned by a dynamic mask, passes through a transparent substrate to cure
photopolymer resin layers that grow progressively from the substrate surface. When compared
to existing Stereolithography techniques, this technique eliminates the necessity of recoating,
reducing process time and improving accuracy. A film of varying thicknesses can be fabricated
on flat or curved transparent substrates. Models of the optical system and resin cure are
developed and reported. An existing MPµSLA process planning method is being extended to
account for radiation transmission through a substrate. The models are verified using
experiments.",,,,,,
"['Fischer, M.', 'Schöppner, V.']",2021-10-18T20:32:46Z,2021-10-18T20:32:46Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89236,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'ABS-M30', 'mass finishing', 'dimensional accuracy']",Finishing of ABS-M30 Parts Manufactured with Fused Deposition Modeling with Focus on Dimensional Accuracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5eacedd-961c-45c3-9fd7-4df85790cb77/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) parts are prone to process-related rough and wavy
surfaces with stair-stepping effects whenever the parts produced have sloped or rounded
geometries. These stair-stepping effects can be reduced by using a smaller slice height, but
complete elimination is not possible. In this paper, FDM parts manufactured with the material
ABS-M30 are finished using mass finishing methods. The mass finishing is done with a trough
vibrator, which is comparatively gentle to the parts in comparison to other mass finishing
technologies. The analysis discusses the surface-smoothing effect of finishing time and intensity
on various part sizes and build orientations. In addition, the dimensional accuracy of the parts
after the finishing process is examined.",,,,,,
"['Wang, Xuanping', 'Li, Shichong', 'Fu, Youzhi', 'Gao, Hang']",2021-11-01T22:55:10Z,2021-11-01T22:55:10Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89791,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'abrasive flow machining', 'polishing', 'complex structure']",Finishing of Additively Manufactured Metal Parts by Abrasive Flow Machining,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc9c15f4-a8a8-44dd-971b-447020456161/download,University of Texas at Austin,"Surface finishing is still a crucial challenge in metal Additive Manufacturing (AM) as the
as-built surface roughness is difficult to fulfill service requirements, due to staircase effect,
balling effect inherent to AM. Abrasive flow machining (AFM) is a non-conventional finishing
technique that offers better accuracy and efficiency for parts with difficult-to-access structures,
and the application of AFM to finishing metal parts of AM process is discussed in this paper. The
aluminum and titanium grilles by selective laser melting are taken to explore the finishing effect
of outer and inner surfaces. The AFM process parameters of abrasive grits sizes, abrasive media
viscosity, and tooling designs are optimized to implement effective material removal from the
outer and inner surfaces. The results show that the AM grille parts with non-trial internal
structures can be finished efficiently and consistently by AFM.",,,,,,
"['Schmid, M.', 'Simon, C.', 'Levy, G.N.']",2021-09-28T18:07:44Z,2021-09-28T18:07:44Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88140', 'http://dx.doi.org/10.26153/tsw/15081']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['plastic part coating', 'Selective Laser Sintering', 'Rapid Manufacturing']",Finishing of SLS-Parts for Rapid Manufacturing (RM) - A Comprehensive Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/abce9469-027d-4b12-8eb8-b572c0fbdaca/download,University of Texas at Austin,"Plastic parts are often coated to fulfill the desired functional requirements during product life. 
This may be for decorative purposes only, but also for functions such as improved tribology, 
wear and humidity resistance, UV- and light stability, hygienic and biofilm resistance. Moving 
SLS towards Rapid Manufacturing (RM) and making those parts competitive with parts produced 
by other techniques (e.g. injection molding) implies the adoption of a new quality of part 
finishing and coating strategy for SLS. This paper provides a survey of current finishing methods 
used for RM-SLS parts in our institute and highlights the manually-driven process steps. The 
need for, and first trials with, a more automated finishing process (e.g. vibratory grinding) are 
discussed, as is the need for innovative supporting software tools.",,,,,,
"['Reeves, P.E.', 'Cobb, R.C']",2018-10-05T16:45:43Z,2018-10-05T16:45:43Z,1995,Mechanical Engineering,doi:10.15781/T27W67R07,http://hdl.handle.net/2152/68714,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'model geometry', 'Rapid prototyping']",The Finishing of Stereolithography Models Using Resin Based Coatings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/96f427a1-82d7-4fab-b04d-c77501c691e7/download,,"The use of StereoLithography (SL) can produce accurate prototype models with complex
internal and external features. However, a major problem to commercial use is the poor surface finish
caused mainly by 'stair stepping' which is inherent in layer manufacturing. Models are often finished
by hand but this is labour intensive, highly selective and causes inaccuracies in the model geometry. A three-year research project has been undertaken to address these issues and to investigate
a range of surface coatings and mechanical finishing processes applied to SL models. This paper
describes some initial findings using resin coatings applied to both cured and uncured SL parts.Initial findings suggest that excess resin retained after part stripping can result in a lower
surface roughness than parts thoroughly cleaned prior to post curing.Through the addition of
photocurable and epoxy based resins to parts in both the un-cured, green and cured states, surface
roughness has been seen to be reduced by up to 50% on complex parts.",,,,,,
"['Hague, Richard', 'Dickens, Phill']",2018-11-16T15:13:19Z,2018-11-16T15:13:19Z,1996,Mechanical Engineering,doi:10.15781/T2FX74J0W,http://hdl.handle.net/2152/70285,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SL models', 'Quickcast', 'autoclaving']",Finite Element Analysis and Strain Gauging of the Stereolithography/Investment Casting System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fe26733f-841c-441a-958e-d15cc416f93e/download,,"Many metal parts have been produced from stereolithography (SL) models via the
investment casting route. However, it is still not possible for every foundry to directly use SL
models as thermally expendable patterns and gain the same success as achieved with wax patterns.
Significant drawbacks still exist with the QuickCastTM structure that restricts its use to specialist
investment casting foundries who are willing to alter their standard techniques.
As part of a continuing work programme at the University ofNottingham, the stresses that
are created in the SL/ceramic construction have been determined using simple stress analysis and
finite element analysis techniques. Further work has involved connecting strain gauges and
thermocouples to SL parts in order to confirm the results obtained with the theoretical stress
analysis. Inspection of the results obtained is aiding the generation of new build structures to
enable the successful autoclaving of SL models.
Details ofthe work to date are outlined in this paper, along with the results obtained.",,,,,,
"['Dalgarno, K.W.', 'Childs, T.R.C.', 'Rowntree, I.', 'Rothwell, L.']",2018-11-16T15:54:43Z,2018-11-16T15:54:43Z,1996,Mechanical Engineering,doi:10.15781/T2PG1J764,http://hdl.handle.net/2152/70291,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLS process', 'analytical procedures', 'rectangular polycarbonate']",Finite Element Analysis of Curl Development in the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9d3650a1-3df4-41f9-859b-792e028def2e/download,,"The work reported within this paper is concerned with the development of analytical
procedures which will allow the accuracy of parts generated by selective laser sintering to be
predicted. One source of inaccuracy is curl, which results in curved part edges of flat plates
manufactured lying horizontally in the part bed. This paper reports on the use of finite element
techniques to model the development of curl. The models have been validated through
comparison of f.e. results with the results of experimental builds, and extended to allow the
influence of ""bases"" on the development of curl to be examined.",,,,,,
"['Jiang, Wei', 'Dalgarno, K.W.']",2019-10-24T17:37:30Z,2019-10-24T17:37:30Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77403', 'http://dx.doi.org/10.26153/tsw/4492']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Deformations,Finite Element Analysis of Residual Stresses and Deformations in Direct Metal SLS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/72ce74ae-69a8-4f14-8364-9c8b18d57b56/download,,"Direct metal SLS processes use a high power laser beam to selectively fuse fully metallic
powder to directly produce functional metal components or tooling. As a thermal dynamic process,
it inevitably causes thermal stresses, stress-induced deformations and cracking. Understanding
these is very important in controlling residual stresses and stress-induced deformations.
In this research, the residual stresses and deformations in direct laser sintering of stainless
steel is investigated by an integrated thermal and mechanical model. Temperature-dependent
material properties are taken into account in both models. Using a commercial finite element
software, with sintered geometry and temperatures imported from a thermal model, the residual
stresses and deformations of direct SLS of stainless steel are predicted. In the long term this will
make it possible to achieve minimum residual stresses and deformations by controlling the SLS
process parameters, material properties and other relevant parameters.","WEI JIANG gratefully acknowledge financial support from the China Scholarship Council under
Grants 99821129 and National Science Foundation of China under Grants 59935110.",,,,,
"['Dai, K.', 'Crocker, J.', 'Shaw, L.', 'Marcus, H.']",2019-09-23T16:45:26Z,2019-09-23T16:45:26Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75965', 'http://dx.doi.org/10.26153/tsw/3064']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Element,Finite Element Analysis of the SALDVI Process 393,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a35ff381-3585-41a6-9e6f-b910e6be98ba/download,,"Selective Area Laser Deposition Vapor Infiltration (SALDVI) is a developing solid freeform fabrication (SFF) technique aimed at the direct fabrication of ceramic and ceramic/metal structures and composites. SALDVI uses a layer-by-layer approach in which
layers of powder are densified with solid material deposited from gas precursors by chemical vapor deposition (CVD) using laser heating. In this work, we have performed numerical simulation using the ANSYS code with 3-dimensional coupled field elements to calculate the temperature field and the part geometry resulting from the SALDVI process. The effects of the powder and vapor deposited material properties on the temperature distribution and the part geometry have been investigated. The result from the numerical simulation is found to be consistent with those obtained from experiments performed using the silicon carbide forming gas precursor Si(CH3)4 and SiC powder particles.",The authors gratefully acknowledge financial supports provided by the National Science Foundation under Grant No: DMI-9908249 and the Office of Naval Research under Grant No: N00014-95-1-0978.,,,,,
"['Weissman, E.M.', 'Hsu, M.B.']",2018-04-12T18:55:23Z,2018-04-12T18:55:23Z,1991,Mechanical Engineering,doi:10.15781/T2P55F05P,http://hdl.handle.net/2152/64286,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['ABS powder', 'polymer powder', 'conductivity']",A Finite Element Model of Multi-Layered Laser Sintered Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a4d9b115-28b1-4d5a-8f3d-7f3636ed2cf1/download,,"Afinite element heat transfer analysis is applied to the selective laser sinteringofa layered part made
frompolyroerpowder. The sinteringsubroutine in the code is based on the analyses of Scherer [l t2] and
Mackenzie and Shuttleworth [3]. The density and conductivity of the particle bed are treated as functions of
the void fraction of the bed. The Yagi - Kunii [4] thermal characterization of the powder bed is used to calculate
the effective conductivity of the bed. An example is worked for ABS powder.",,,,,,
"['Sealy, M.P.', 'Madireddy, G.', 'Li, C.', 'Guo, Y.B.']",2021-10-26T19:00:54Z,2021-10-26T19:00:54Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89557,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['hybrid', 'SLM', 'laser shock peening', 'Ti64', 'residual stress']",Finite Element Modeling of Hybrid Additive Manufacturing by Laser Shock Peening,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7a33d493-9cfa-4345-8ef6-ed86fc8ce04e/download,University of Texas at Austin,"Hybrid manufacturing has traditionally targeted efficiency and productivity as improvement
criteria. However, the advent of additive manufacturing to print functional parts has expanded the
possibilities for a hybrid approach in this field. Hybrid additive manufacturing is the combination
of two or more manufacturing processes or materials that synergistically affect the quality and
performance of a printed part. Hybrid additive manufacturing allows for advancements in material
properties beyond efficiency and productivity. Mechanical, physical, and chemical properties can
be designed and printed. The purpose of this study was to model a hybrid additive manufacturing
process to investigate the resulting mechanical properties. Laser shock peening (LSP) was coupled
with selective laser melting in a 2D finite element simulation in Abaqus to quantify the resulting
residual stress fields. The effects of peak pressure and layer thickness were studied when coupling
laser shock peening with selective laser melting.",,,,,,
"['Arrieta, E.', 'Mireles, Jorge', 'Stewart, C.', 'Carrasco, C.', 'Wicker, R.']",2021-11-09T20:19:21Z,2021-11-09T20:19:21Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90155', 'http://dx.doi.org/10.26153/tsw/17076']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['lattices structures', 'Ti-6Al-4V', 'EBM', 'FEA', 'DIC']",Finite Element Modeling of Metal Lattices Using Commercial FEA Platforms,Conference paper,https://repositories.lib.utexas.edu//bitstreams/687a4ac9-69e1-44d4-b64b-cbbdca13ac9f/download,University of Texas at Austin,"The introduction of geometrical features into standard solids result in cellular materials
with unique performances. The deformation mechanisms originated by the introduced geometry
may not be entirely captured by the current commercial FEM software; resulting in inaccuracies
in predicting the performance of cellular metals. Additionally, the inconsistency of AM material
properties will result in material models with uncertainty, thus, contributing to the inaccuracy of
simulations. The present work shows a process for modeling the strength of EBM Ti-6Al-4V
lattices structures; starting from the definition of the convenient experiments to generate the data
for the development of material models at different orientation and finalizes with the assignment
of these material models to the lattice FEMs. MSC Patran/Nastran is used in this work.
Experimental results of the compressive strength of lattice structures are compared with those from
the FEM utilizing the different material models created from the experiments.",,,,,,
"['Olleak, Alaa', 'Xi, Zhimin']",2021-11-11T16:39:13Z,2021-11-11T16:39:13Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90241', 'http://dx.doi.org/10.26153/tsw/17162']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['finite element modeling', 'selective laser melting', 'Ti-6Al-4V', 'thermal model', 'thermo-mechanical model']",Finite Element Modeling of the Selective Laser Melting Process for Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78ee065f-7d90-4852-a313-6f992fc18692/download,University of Texas at Austin,"Physics-based modeling of the selective laser melting (SLM) process is critical for
better understanding the influence of the parts quality with respect to various process
parameters and scanning strategies. The challenge is to balance model validity, domain
size, and computational efficiency so that the model can be practically useful for
improving reliability and quality of the printed products. In this paper, a transient
thermal finite element model of a SLM process for Ti-6Al-4V is developed using
ANSYS for predicting the melt pool size and thermal history. The thermal solution is
remapped to the structural problem to predict the induced residual stress of the
products. The thermo-mechanical model is capable of handling practical domain size
with reasonable computational efficiency on the process level, by developing the remeshing and remapping technique that adapts with the scanning vector.",,,,,,
"['Wang, Zhaogui', 'Fang, Zhenyu', 'Smith, Douglas E.']",2021-12-07T17:45:50Z,2021-12-07T17:45:50Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90733', 'http://dx.doi.org/10.26153/tsw/17652']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['flow dynamics', 'fiber reinforced thermoplastics', 'direct deposition', 'additive manufacturing']",Finite Element Simulation of Direct Deposition Additive Manufacturing for Fiber Reinforced Thermoplastics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6384a95-6264-44f8-bc99-168dbebff7fd/download,University of Texas at Austin,"Non-planar direct deposition additive manufacturing of polymer composites has recently
seen increased attention from industries, where the molten plastics beads are extruded through a
heated nozzle directly into three-dimensional space to form lightweight truss-like structures. This
promising method shortens the manufacturing time and fabricates structures without stair-effect
appearance that occurs in traditional layered additive manufacturing processes. This paper
investigates the flow dynamics of fiber reinforced thermoplastics melt during a direct deposition
process via a 2D planar deposition flow model. A quasi steady state for the deposition flow is
assumed, where the flow-induced fiber orientation is evaluated through the Folgar-Tucker
isotropic rotary diffusion model with the orthotropic-fitted closure approximation. The direct
deposition process of a cubic lattice is simulated using finite element suite ABAQUS, where the
orientation-homogenized material properties of a 13% CF-ABS are employed. Computed results
indicate printing sequence affects the stress accumulation of the printed part notably.",,,,,,
"['Faustini, Mario', 'Lokhande, Mahendra', 'Crawford, Richard', 'Rogers, William', 'Gitter, Andrew', 'Bosker, Gordon']",2019-10-18T15:39:17Z,2019-10-18T15:39:17Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76242', 'http://dx.doi.org/10.26153/tsw/3331']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Prosthesis,Finite Element Structural Analysis of Prosthesis Sockets for Below-the-Knee Amputees Manufactured Using SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c47a7f6e-189c-4bd1-9481-a856ac8d67b8/download,,"A very attractive application of Solid Freeform Fabrication is manufacture of prosthesis sockets
for below-the-knee amputees. The custom geometric design required is very compatible with
SFF techniques. The present work focuses on finite element analysis of sockets manufactured by
Selective Laser Sintering using Duraform as the material. The objective is to ensure reliability of
the sockets for their use by patients. This paper describes the finite element models developed
for the sockets, as well as the derivation of realistic boundary conditions that may allow a
simulation of the structure under regular workloads.",,,,,,
"['Johnston, S.', 'Anderson, R.']",2019-10-24T18:12:30Z,2019-10-24T18:12:30Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77415', 'http://dx.doi.org/10.26153/tsw/4504']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Metal Matrix,Finite Element Thermal Analysis of Three Dimensionally Printed (3DP™) Metal Matrix Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f8e8989-652e-405f-96a9-927ff4b7aa77/download,,"Three Dimensional Printing, 3DP™, is under development for the production of metal
composites through solid freeform fabrication of a skeleton, followed by sintering and then
infiltration of a second, lower melting metal. To maintain dimensionality and allow for
infiltration, green component sintering produces only neck growth between powder particles,
which differs substantially from conventional powder metallurgy sintering practices. The
objective of this study is to investigate finite element thermal-mechanical modeling in order to
optimize the sinter profile and predict the final part dimension. The model will relate micro-scale
thermal effects to the macro-scale by analyzing the composite medium as a meshed layered
element comprising micro-scale elements. The micro-scale elements can be based on bulk
transport mechanisms related to neck growth. The analytical model will eventually be used to
define the thermal processing parameters and to predict optimal geometry for full density near
net shape sintering and infiltration of 3DP™ manufactured components.","Financial support for this work is provided by the Office of Naval Research, Contract
#N00014-C-00-0378.",,,,,
"['Doubrovski, E.L.', 'Verlinden, J.C.', 'Horvath, I.']",2021-10-06T22:33:56Z,2021-10-06T22:33:56Z,8/18/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88461', 'http://dx.doi.org/10.26153/tsw/15398']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Design for Additive Manufactured', 'Additive Manufacturing', 'open-ended knowledge', 'wiki environment']",First Steps Towards Collaboratively Edited Design for Additive Manufacturing Knowledge,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4776a124-b43e-4435-87ce-17bb7da2d6b1/download,University of Texas at Austin,"Despite the broad coverage concerning the technological challenges, little research has been performed
on the methods that enable designers to deal with Additive Manufacturing. At present, the challenge is to
generate Design for Additive Manufacturing knowledge which goes beyond traditional solutions and to ensure
that this knowledge is complete, correct and up to date. This paper reports on the employment of a wiki
environment to support open-ended knowledge management. We applied this solution in an undergraduate
prototyping course focused on exploring visual properties using AM structures. The results of the 32 students
encompass unexpected designs while the knowledge on the wiki encompassed i) AM processes, ii) procedures,
iii) artifacts. This forces us to rethink what should constitute DfAM.",,,,,,
"['Mahale, Tushar R.', 'Taylor, James B.', 'Cormier, Denis R.']",2019-09-23T16:08:10Z,2019-09-23T16:08:10Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75951', 'http://dx.doi.org/10.26153/tsw/3050']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Thermoplastic,Five-Axis Freeform Fabrication of Solid Thermoplastic Parts via SWIFT 289,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8fd06535-b40a-4bb3-bd9b-b56380c18a69/download,,"Current Rapid Prototyping (RP) & Layered Manufacturing (LM) techniques are based on controlled, precise additive manufacturing methods. These techniques suffer from problems associated with stair stepping, loss of accuracy in the z-direction due to limitations on the slice thickness and their build speeds which prevent them from being “rapid”. Proposed here, is a method, which utilizes a freeform fabrication technique, coupled with the advantages and precision of five axis machining for contoured edge generation. A new technique for the generation of solid thermoplastic parts (ABS, Polystyrene, etc) will be introduced. The proposed process will incorporate adaptive slicing for the generation of five-axis CNC code, and a sub-layer machining technique for use of uniform layer thickness will be outlined. A novel 5-axis configuration will be proposed. The proposed process will decrease, drastically, the time required for part production when compared to current commercial technologies.",,,,,,
"['Lao, S.C.', 'Koo, J. H.', 'Moon, T. J.', 'Yong, W.', 'Lam, C.', 'Zhou, J.', 'Hadisujoto, B.', 'Wissler, G.', 'Pilato, L.', 'Luo, Z. P.']",2020-03-10T17:11:24Z,2020-03-10T17:11:24Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80231', 'http://dx.doi.org/10.26153/tsw/7250']",eng,2008 International Solid Freeform Fabrication Symposium,Open,rapid manufacturing,Flame Retardant Intumescent Polyamide 11 Nanocomposites – Further Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0bf9419c-c134-4b39-afe4-169d52928e5f/download,,"The objective of this research is to develop improved polyamide 11 and 12 polymers with
enhanced flame retardancy, thermal, and mechanical properties for selective laser sintering
(SLS) rapid manufacturing (RM). In the present study, a nanophase was introduced into the
polyamide 11 and combine with a conventional intumescent flame retardant (FR) additive via
twin screw extrusion. Arkema Rilsan® polyamide 11 molding polymer pellets were used with
two types of nanoparticles such as: chemically modified montmorillonite (MMT) organoclays
and carbon nanofibers (CNFs). Two types of Clariant’s Exolit® OP 1311 and 1312 intumescent
FR additives were used to generate a family of FR intumescent polyamide 11 nanocomposites
with anticipated synergism.",,,,,,
"['Lao, S.C.', 'Koo, J.H.', 'Moon, T.J.', 'Hadisujoto, B.', 'Yong, W.', 'Pilato, L.', 'Wissler, G.']",2021-09-29T14:53:20Z,2021-09-29T14:53:20Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88188', 'http://dx.doi.org/10.26153/tsw/15129']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['flammability properties', 'thermal properties', 'mechanical strength', 'polyamide 11 polymer nanocomposites', 'laser sintering', 'rapid manufacturing']",Flammability and Thermal Properties of Polyamide 11-Alumina Nanocomposites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7197060c-acba-4cd2-a810-fe619e5ac3b5/download,University of Texas at Austin,"Neat polyamides 11 and 12 lack high strength/high heat resistance and flame retardancy.
The incorporation of selected nanoparticles is expected to enhance these properties to a
level that is desired and required for performance driven applications. This enhancement
may result in additional market opportunities for the polyamide 11 and 12 polymer
manufacturers. The objective of this study is to develop polyamide 11 polymer
nanocomposites with enhanced thermal, flammability, and mechanical performance for
selective laser sintering (SLS) rapid manufacturing. Three types of nano-alumnia (X-0
needle, X-25SR, and X-0SR) with different organic treatments were melt-compounded
into polyamide 11 in three different weight loadings of the nanoparticles (2.5%, 5%, and
7.5%). Injection molded specimens were fabricated for thermal, flammability, and
mechanical properties characterization. Although nano-alumina was uniformly dispersed
in polyamide 11 and better thermal stability of the nanomodified materials was observed,
the desired FR characteristics of the nanomodified polyamide 11 was not achieved. None
of the materials passed the desired UL 94 V0 rating.",,,,,,
"['Kraft, Stefan M.', 'Lattimer, Brian Y.', 'Williams, Christopher B.']",2021-11-01T22:33:37Z,2021-11-01T22:33:37Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89785,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['flammability', 'material compositions', 'object geometry', '3D printing', 'additive manufacturing']",Flammability of 3-D Printed Polymers – Composition and Geometry Factors,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99fcd254-b6e3-4d7c-9848-79d0956a6ab9/download,University of Texas at Austin,"The focus of this paper is to evaluate the comparative flammability of additively manufactured
(AM) and conventionally molded polymers. Flammability of objects is dependent on two main
factors: material composition and object geometry. To evaluate effects of material composition,
experiments on polymer samples made via conventional molding and via AM were performed
using an ASTM E1354 cone calorimeter to measure and compare material ignitability and heat
release rate. ULTEM™ (amorphous thermoplastic polyetherimide) and PPSF/PPSU
(polyphenylsulfone) heat release rates were about 10 times lower than ABS (acrylonitrile
butadiene styrene). This was in part due to the large char layer formed by these materials during
burning. Comparisons between conventional molded and AM materials revealed slight differences
in heat release rate. Additively manufactured ABS sheets had about a 17% higher mean average
heat release rate (MAHRR). Conversely, the characterization of ULTEM 9085™ sheets revealed
the MAHRR of the AM samples were 13% lower than the molded samples. This is attributed to
additives in the material used for extrusion AM as well as the build process itself. Effects of
geometry were assessed using material cribs, which were composed of layers of rectangular prisms
separated by air gaps, with prisms on consecutive layers being orthogonal. Cribs were constructed
with three to ten prisms per layer to evaluate the effects of varying the internal material surface
area. Below a specific threshold, the burning mass loss rate per unit area of the cribs decreased
with an increase in internal material surface area; this agrees with trends predicted using a
theoretical model previously developed for wood cribs.",,,,,,
"['Rock, Stephen J.', 'Wozny, Michael J.']",2018-04-12T18:00:41Z,2018-04-12T18:00:41Z,1991,Mechanical Engineering,doi:10.15781/T2ZP3WH3Q,http://hdl.handle.net/2152/64275,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Rensselear Design Research Center', 'Rensselaer Polytechnic Institute', 'CAD systems', 'CSG']",A Flexible File Format for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/366f6df1-f552-4658-8860-e23e9bffd324/download,,"A flexible file format for Solid Freeform Fabrication data is presented which
significantly improves on the de-facto industry standard STL format. The new format
removes the redundancy present in STL files and can contain topological information. Its
specification flexibility allows users to balance storage and processing costs. Since facet
boundary models currently provide the greatest common denominator for data exchange
between many CAD systems, they are supported by this format. Additionally,
representation of CSG primitives is provided, as are capabilities to represent multiple
instances of both facet and CSG solids. Format extensibility, without obsoleting existing
programs, is made possible by interleaving the format schema with the data. User data can
be added to existing entities, or new entities can be created. This allows the addition of
NURBS based geometries in the future.",,,,,,
"['Lai, Cheukfung', 'Gibson, Ian']",2019-09-23T16:03:42Z,2019-09-23T16:03:42Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75949', 'http://dx.doi.org/10.26153/tsw/3048']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,A Flexible Rapid Prototyping Cell 275,Conference paper,https://repositories.lib.utexas.edu//bitstreams/026f7a23-3117-44b4-b018-b587294abe78/download,,Rapid prototyping systems have demonstrated high flexibility in terms of creating complex geometry parts. Improvements in accuracy and material properties enable rapid prototyping to become a widely used and important part of the product development process. Further applications and further improved performance can be achieved by combining rapid prototyping machines with conventional machine tools to form flexible manufacturing cells. One way to form such a cell is to integrate with industrial robotics. This paper will describe work carried out using an ABB IRB 1400 industrial robot in conjunction with a DTM Sinterstation 2000 to form a Flexible Rapid Prototyping Cell.,,,,,,
"['Somireddy, Madhukar', 'de Moraes, Diego A.', 'Czekanski, Aleksander']",2021-11-03T20:26:20Z,2021-11-03T20:26:20Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89923,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laminates', 'flexural behavior', '3D printing', 'fused deposition modeling']","Flexural Behavior of FDM Parts: Experimental, Analytical and Numerical Study",Conference paper,https://repositories.lib.utexas.edu//bitstreams/67a320d6-1306-405a-9a5f-7340c0723e72/download,University of Texas at Austin,"Fused deposition modelling (FDM) processed parts behave as composite laminate structures. Therefore,
mechanics of composite laminates can be adopted for the characterization of mechanical behavior of the printed
parts. In this study, the flexural properties of the 3D printed laminates are investigated experimentally, analytically
and numerically. Each layer of the printed specimens is treated as an orthotropic material. The elastic moduli of
a lamina are calculated by considering the mesostructure of the printed laminate in finite element simulation of
tensile testing. These elastic moduli are employed in a constitutive matrix for the calculation of flexural stiffness
of the laminate using classical laminate theory. Then 3-point bending tests are conducted on the printed laminates
to calculate their flexural stiffness. The influence of road/ fiber size and lamina layup on the flexural properties
are also investigated. Furthermore, failure phenomena of printed laminates under bending loads is investigated.",,,,,,
"['Currence, Jacob', 'Morales-Ortega, Rolando', 'Steck, Jason', 'Zhou, Wenchao']",2021-11-04T14:43:44Z,2021-11-04T14:43:44Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89973,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'cooperative 3D printing', 'power system', 'mobile robot']",A Floor Power Module for Cooperative 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6aa9851e-6fd8-445c-a32b-8063cc1244a4/download,University of Texas at Austin,"Cooperative 3D printing is an emerging technology that utilizes multiple printhead-carrying mobile robots to work simultaneously to 3D print or assemble products on a factory floor,
which can provide the scalability, increased printing capability, and reduced human intervention
for 3D printing to potentially become a mainstream digital manufacturing technology. However,
powering the mobile printers for them to span entire factory floors poses an issue. Traditional cords
are not an option due to restricting free movement across long distances. On-board batteries would
waste energy due to additional weight and the need to recharge could interrupt ongoing print jobs
and increase printing time. In this paper, we present an electrified floor to power the mobile printers
wirelessly. First, we designed a floor module with stainless steel conductive strips in a concrete
base and a brush that is carried by the mobile robots to make sure it never loses contact with the
electrified floor while in motion. Then we designed a circuit to sort the polarity of the current from
the floor based on the power requirements of the robot. A prototype of the floor power module
was then developed and tested with a mobile 3D printer. Results show the developed floor power
supply can power the mobile 3D printers effectively. This development will potentially enable an
autonomous factory equipped with thousands of mobile 3D printers powered wireless by the
factory floor.",,,,,,
"['Balderrama-Armendariz, Cesar O.', 'MacDonald, Eric', 'Valadez, Esdras D.', 'Espalin, David']",2021-11-01T22:20:11Z,2021-11-01T22:20:11Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89779,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['folding endurance', '3D printing', 'fusion deposition modeling']",Folding Endurance Appraisal for Thermoplastic Materials Printed in Fusion Deposition Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6726b054-2481-44b1-bb7b-f3fccd88456e/download,University of Texas at Austin,"The anisotropic behavior of the fusion deposition modeling (FDM) machines could
change the mechanical properties of the materials in the layer by layer technology. In general, the
tensile, compressive and flexural strength are decreased against molded plastics. Some lasting
products need the iteration of low flexural strength and high elongation to obtain an effective
flexibility to bend in repetitive movements. The present work provides an analysis of the capacity
of several selected thermoplastics materials such as Nylon (PA), Polyethylene Terephthalate
(PETG), Polylactide (PLA), Polyurethane (TPU) and Polypropylene (PP) in order to test the
maximal load capacity and the number of folding cycles sustained in perpendicular direction of
movement. Results demonstrate that those of similar to injected molded products, PP and
TPU materials surpass one million of cycles in the folding test. Yet, in axial load they have lower
strength against the other considered materials.",,,,,,
"['Norrell, Jeffery L.', 'Wood, Kristin L.', 'Crawford, Richard H.', 'Bergman, Theodore L.']",2018-11-15T20:44:22Z,2018-11-15T20:44:22Z,1996,Mechanical Engineering,doi:10.15781/T2C53FM56,http://hdl.handle.net/2152/70278,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLS powder beds', 'thermal behavior', 'Rapid prototyping']",Forced Convection in a Polymeric Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef939827-081a-40d0-b932-5f2092623559/download,,"In a Selective Laser Sintering (SLS) powder bed, thermal transfer occurs through multiple modes.
Forced convection through the powder, or downdraft, has recently been implemented in SLS machines
in an effort to enhance thermal transfer within the powder bed. In this paper, forced convection
is analytically shown to be a significant thermal transfer mode for low porosities, such as seen
in SLS powder beds. A polymeric powder bed subjected to downdraft is investigated with the goal
of quantitatively determining thermal behavior. A numerical model describing heat transfer within
a powder is presented. The design and construction of an experimental apparatus to measure the
temperature profiles within a powder subjected to forced convection is described. Using the information
gained in these experiments, it may be possible to better control the thermal environment
of SLS powder beds, reducing growth and internal stress build-up.",,,,,,
"['Crockett, Robert S.', 'Zick, Rebecca']",2019-09-23T17:22:37Z,2019-09-23T17:22:37Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75982', 'http://dx.doi.org/10.26153/tsw/3081']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Fabrication,Forensic Applications of Solid Freeform Fabrication 549,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6039e524-fa20-46ac-b9bd-2c4fa1b3c3a5/download,,"Solid Freeform Fabrication was recently used to identify the dismembered body of a woman found in rural Wisconsin. Skin from the face of the victim had been removed, making visual identification impossible. A model of the skull was constructed by Laminated Object Manufacturing (LOM), using data extracted from CT scans of the victim’s head. Forensic anthropologists performed a facial reconstruction directly on the LOM model, which was then photographed and distributed. The computer model was further manipulated and served as supplemental data to investigators preparing the reconstruction. An identification from one of the distributed photographs led to the arrest of a suspect and a subsequent conviction. This is the first example that we are aware of where SFF has been used in an active criminal case, and the successful results show a promising future for SFF as a forensic tool.","We also gratefully acknowledge the financial support of the National Science Foundation and the MSOE Rapid Prototyping
Consortium, as well as the facilities and expertise provided by the staff of the MSOE Rapid Prototyping Center.",,,,,
"['Tagore, G.R.N.', 'Anjikar, Swapnil D.', 'Gopal, A. Venu']",2020-03-09T14:26:59Z,2020-03-09T14:26:59Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80185', 'http://dx.doi.org/10.26153/tsw/7204']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Form Accuracy Analysis of Cylindrical Parts Produced by Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4d45f8a-4cb3-4ee7-bf41-d3c0bd47192b/download,,"Solid Freeform fabrication processes are being considered for creating fit and assembly
nature functional parts. It is extremely important that these parts are within allowable
dimensional and geometric tolerance. The part accuracy produced by rapid prototyping process
is greatly affected by the relative orientation of build and face normal directions. A systematic
method is needed to find the reliability of the created product. This paper discusses the work
done in this area and the effect of build orientation on the part form accuracy analysis of each
specified tolerance like circularity and cylindricity. Feasible build direction that can be used to
satisfy those tolerances is identified. It will help process engineer in selecting a build direction
that can satisfy a mathematical model of form tolerance.",,,,,,
"['Sperry, M.G.', 'Carter, D.', 'Crane, N.B.', 'Nelson, T.W.']",2024-03-25T23:57:15Z,2024-03-25T23:57:15Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124347', 'https://doi.org/10.26153/tsw/50955']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['selective doping', 'laser powder bed fusion', 'additive manufacturing']",Formation of Easy-To-Remove Supports in Laser Powder Bed Fusion through Selective Doping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0c27e175-8846-4722-b345-b35ce6c28627/download,University of Texas at Austin,"Laser Powder Bed Fusion (LPBF) is a popular Additive Manufacturing
(AM) technique used c01m11only for metals. Metal paiis formed by LPBF
generally require supports connecting the part to the print bed to hold up the
strncture, remove heat, and minimize deformation due to solidification
shrinkage. Because of these suppo1is, finished parts must be cut away from
the build plate, and generally require additional machining to achieve the
desired geometry. In this study, a carbon suspension was deposited in the
3 l 6L stainless steel powder bed at the interface between the support and the
finished part. The added carbon reduces the co1Tosion resistance of the
3 l 6L. This allows full fusion of the support material to provide heat transfer
and mechanical support during printing, while allowing the supports to etch
preferentially by electrolytic etching. This causes the finished part to etch
or break free from the supports without any need for machining, simplifying
post-processing.",,,,,,
"['Das, Anirban', 'Dasgupta, Niladri', 'Gurumoorthy, B.', 'Umarji, A. M.']",2019-06-13T14:05:35Z,2019-06-13T14:05:35Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/74941', 'http://dx.doi.org/10.26153/tsw/2053']",eng,2000 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'polymer', 'Lamination']",Formulation of Lamination Conditions and Interface Studies using Acrylic Binder System for LOM 9,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0350f683-ba65-4471-b653-ecf8a3e0d936/download,,"A multicomponent binder-plasticiser system based on acrylates was formulated for
making flexible tapes of Alumina (58 volume %), to be used for Laminated Object
Manufacturing. Optimum lamination parameters were arrived at by viscosity measurement of the
binder-plasticiser system and dilatometry of the compounded tapes . Lamination was done at five
different temperatures (75, 85, 90, 95 and 110°C) with solvent (toluene-butanol) spray and under
three different pressures ( below 50 psi). The interlaminar strength was measured and interface
studies were made using SEM .The shrinkage along the Z direction during lamination was in the
range of 1.7-3.5%. Highest interlaminar strength and defect free lamination could be achieved at
the intermediate temperature of 90o
C, due to sufficient reduction of polymer viscosity and
presence of solvent.",,,,,,
"['Zhou, Jack G.', 'He, Zongyan', 'Guo, Jian']",2019-03-12T16:49:03Z,2019-03-12T16:49:03Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73601', 'http://dx.doi.org/10.26153/tsw/743']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SALD', 'ECLD-SFF']",Fractal Growth Modeling of Electrochemical Deposition in Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be7947f7-b5a0-4494-aaae-8410e07441a8/download,,"A new rapid tooling technique ElectroChemical Liquid Deposition Based Solid Freeform
Fabrication (ECLD-SFF) was introduced in this paper. In the ECLD-SFF a substrate made of or
coated with conductive materials is connected to a DC power supply, and the substrate is put into
a plating bath. A very thin metal pin is connected to the DC power as a positive electrode.
Between the substrate and the tip of the pin there is a thin layer of metal powder. Under the
effects of electric field, metal ions from electrode moving to chemical liquid will deposit onto the
powder particle and growing so that the metal particles can be bound by the deposited materials
to form freeform solid. By controlling the pin's movement and electrified time, a desired 3-D
shape will be built through layer by layer scanning. ELCD-SFF distinguishes itself from other
SFF techniques with advantages of products: high build rate, high accuracy, high density, low
shrinkage and controllable microstructures. It has been found that the electrochemical deposition
among metal particles during ECLD-SFF is a fractal growth process. The fractal dimension and
the width of the deposited metal band are all related to electric field density, composition of
electroplating liquid and processing time. Several models on the fractal growth between
electrodes or metal particles were developed in order to explain these fractal growth phenomena
and obtain desired process parameters and conditions for the ECLD-SFF process.",,,,,,
"['Yang, Lei', 'Yan, Chunze', 'Shi, Yusheng']",2021-11-04T20:41:42Z,2021-11-04T20:41:42Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90023', 'http://dx.doi.org/10.26153/16944']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['fracture mechanism', 'TPMS', 'Schoen Gyroid', 'cellular structures', 'selective laser melting']",Fracture Mechanism Analysis of Schoen Gyroid Cellular Structures Manufactured by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d048d1d1-b78f-4aa4-baa5-61e35112188e/download,University of Texas at Austin,"Ti-6Al-4V triply periodic minimal surface (TPMS) structures with biomorphics
scaffold designs are expected to be the most promising candidates for many biological
applications such as bone implants. Fracture is the main failure mode of Ti-6Al-4V
cellular structures at room temperature. However, there is currently less investigation
on general analysis about the fracture mechanism of Ti-6Al-4V TPMS cellular
structures. In this work, a typical TPMS structure, Schoen Gyroid, was designed and
porous Ti6Al4V Schoen Gyroid specimens were manufactured using Selective laser
melting (SLM). Finite element analysis (FEA) method was employed to calculate the
stress distribution under compression. The FEA results are used to predict the fracture
positions, fracture zones as well as fracture mode. The uniaxial compression
experiments were conducted and compared with the FEA results. The experimental and
simulation results show high consistency.",,,,,,
"['McNeil, J. Logan', 'Hamel, William R.', 'Penney, Joshua', 'Nycz, Andrzej', 'Noakes, Mark']",2021-11-18T16:54:47Z,2021-11-18T16:54:47Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90426', 'http://dx.doi.org/10.26153/tsw/17347']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['large scale additive metals manufacturing', 'LSAMM', 'arbitrary directions', 'CAD']",Framework for CAD to Part of Large Scale Additive Manufacturing of Metal (LSAMM) in Arbitrary Directions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9d7bd568-db7d-43ef-9be3-9a7cd2a96565/download,University of Texas at Austin,"The purpose of this research is to provide a framework for Large Scale Additive Metals Manufacturing
(LSAMM) in arbitrary directions. Traditionally, slicing and path planning is done along the gravity aligned
direction of a part, causing more complex geometrical shapes to have unsupported overhangs. The overhangs can
be managed using a part positioner or a powder bed process. A different framework for slicing and building parts
out of gravity alignment could improve current capabilities of LSAMM processes. The presented research focuses
on segmenting more complex geometrical parts into gravity aligned (GA), non-gravity aligned (NGA), and
transition segments to help generate toolpaths. Initial research of segment planning for complex geometrical
shapes will be presented, as well as current results from builds completed at the University of Tennessee-Knoxville. The completed builds show that more consistent thermal evolution of a part based on the path sequence
and torch angle results in successful builds.",,,,,,
"['Wang, Zhiyun', 'Liu, Renwei', 'Sparks, Todd', 'Liou, Frank']",2021-10-19T21:12:39Z,2021-10-19T21:12:39Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89339,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['fused pellet modeling', 'void density', 'accuracy control', 'robot']",A Framework for Large Scale Fused Pellet Modeling (FPM) by An Industry Robot,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a4bfccfb-adaf-4e78-8718-f58f3553c416/download,University of Texas at Austin,"Fused pellet modeling (FPM) is an important method in additive manufacturing
technology, where granular material is used instead of filaments. In FPM, prototypes are
constructed by the sequential deposition of material layers. As the size of the part increases, the
problem of long build times and part deformation becomes critical. In this paper, methods for
eliminating the void density during deposition and accuracy control principles for large scale
FPM processes are studied. By analyzing the ab initio principles of this process, a mini extruder
with variable pitch and progressive diameter screw for the large scale fused deposition is
proposed. Based on polymer extrusion theory and non-Newtonian fluid properties, each of the
design parameters are analyzed, such as the length of different function sections of screw, die
shape of extruder nozzle, and the material properties. According to these analysis results, an
extrusion process simulation for controlling the filament shape is carried out with multi-physics
modeling software and proved the FPM could increase the building efficiency and deposition
quality for large size parts.",,,,,,
"['McNulty, T.', 'Bhate, D.', 'Zhang, A.', 'Kiser, M.A.', 'Ferry, L.', 'Suder, A.', 'Bhattacharya, S.', 'Boradkar, P.']",2021-11-04T19:41:26Z,2021-11-04T19:41:26Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90013', 'http://dx.doi.org/10.26153/16934']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['biomimetic cellular materials', 'classification', 'design framework', 'additive manufacturing']",A Framework for the Design of Biomimetic Cellular Materials for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6639ce49-e514-4465-b661-137d65b2699f/download,University of Texas at Austin,"Cellular materials such as honeycombs and lattices are an important area of research in
Additive Manufacturing due to their ability to improve functionality and performance. While there
are several design choices when selecting a unit cell, it is not always apparent what the optimum
cellular design for a particular application is. This becomes particularly challenging when seeking
an optimal design for more than one function, or when the design needs to transition spatially
between different functions. Nature abounds with examples of cellular materials that are able to
achieve multifunctionality, but designers lack the ability to translate the underlying principles in
these examples to their design tools. In this work, we propose a framework to bridge the gap
between nature and designer. We present a classification of natural cellular materials based on
their structure and function, and relate them in a manner amenable for use in guiding design for
Additive Manufacturing.",,,,,,
"['Weiss, Lee E.', 'Prinz, Fritz B.', 'Siewiork, Daniel P.']",2018-04-17T17:02:12Z,2018-04-17T17:02:12Z,1991,Mechanical Engineering,doi:10.15781/T2J38M13F,http://hdl.handle.net/2152/64334,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Thermal Spray', 'Net Shape Manufacture', 'Rapid Prototyping']",A Framework for Thermal Spray Shape Deposition: The MD* System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8135518c-008f-444f-a18a-678fceaec339/download,,"This paper present.s t.he framework for a solid-freeform-fabrication syst.em based on thermal spray
shape deposition t.o build mult.i-mat.erial st.ruct.ures by incremen tal build-up of t.hin cross-sect.ional layers.
The basis of theMD* System (recursively, Mask and Deposit.) is to spray each layer using disposable
masks to shape each layer. A thermal spray approach has the potential to build dense parts with
desirable mechanical properties. Metal. ceramic, plastic, laminate, and composite structures can be
deposited. Since l11asking enables selective deposition wit.hin a layer, complet.e assemblies composed of
different mat.erials can be creat.ed in a single process. For example, int.egrated electronic/mechanical
structures are feasible.",,,,,,
"['Chatham, C.A.', 'Washington, A.L. II']",2023-03-29T14:47:18Z,2023-03-29T14:47:18Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117674', 'http://dx.doi.org/10.26153/tsw/44553']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,A Framework with Examples for Printing Thermosetting Polymers Using Laser Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c7f7c54a-d881-44e3-b919-1f45bbdabba1/download,,"Thermoset polymers possess traits arising from their covalently crosslinked network 
structure that are distinct from thermoplastic polymers. These traits can manifest as relative 
increases in the performance properties of chemical resistance, stiffness, and strength particularly 
at elevated temperature. Although these performance properties are desired from additively 
manufactured parts, there are few engineering grade thermosetting polymers commercially 
available for any additive manufacturing (AM) fabrication method. This work describes some of 
the challenges when processing and formulating thermosetting powder feedstocks for the laser 
powder bed fusion (L-PBF) mode of AM. The thermal curing properties of three different 
commercially available thermosetting polymers made via L-PBF are compared. Surface 
temperature profiles collected during printing are used to predict the extent of crosslinking through 
a rudimentary isoconversional model and are compared against post-print measurements of 
residual cure.",,,,,,
"['Bampton, C.C', 'Burkett, R.']",2018-11-08T14:55:27Z,2018-11-08T14:55:27Z,1995,Mechanical Engineering,doi:10.15781/T20V8B31P,http://hdl.handle.net/2152/69879,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['free form fabrication', 'SLS', 'alloy systems']",Free Form Fabrication of High Strength Metal Components and Dies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/737b10dc-6599-4944-8309-89988dc5e3d4/download,,"A two-stage method has been devised for free form fabrication of nickel,
iron and copper based alloy parts with shape and property control equal or
superior to investment castings in the same base alloys. A major advantage
of the approach is the ability to utilise commercially available selective laser
sintering systems with virtually no modification from their standard
configurations for plastic model generation. We have demonstrated the
essential feasibility of shape, dimension and property control for complex,
low production volume rocket engine components and for tools and dies in
higher volume commercial production situations. This presentation is limited
in scope to a brief overview of our recent progress.",,,,,,
"['Griffith, M. L.', 'Keicher, D. M.', 'Atwood, C. L.', 'Romero, J. A.', 'Smugeresky, J. E.', 'Harwell, L. D.', 'Greene, D. L.']",2018-11-09T16:21:31Z,2018-11-09T16:21:31Z,1996,Mechanical Engineering,doi:10.15781/T26689430,http://hdl.handle.net/2152/69929,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'LENS', 'stereolithography']",Free Form Fabrication of Metallic Components Using Laser Engineered Net Shaping (Lens),Conference paper,https://repositories.lib.utexas.edu//bitstreams/1975e01c-f42e-40b1-a26b-df29613a77d6/download,,"Solid free form fabrication is one ofthe fastest growing automated manufacturing
technologies that has significantly impacted the length oftime between initial concept and actual
part fabrication1
2. Starting with CAD renditions of new components, several techniques such as
stereolithography3 and selective laser sintering4
are being used to fabricate highly accurate
complex three-dimensional concept models using polymeric materials. Coupled with investment
casting techniques, sacrificial polymeric objects are used to minimize costs and time to fabricate
tooling used to make complex metal castings5
•
This paper will describe recent developments in a new technology, known as LENSTM (Laser
Engineered Net Shaping)6 7 8 9, to fabricate metal components directly from CAD solid models
and thus further reduce the lead times for metal part fabrication. In a manner analogous to
stereolithography or selective sintering, the LENSTM process builds metal parts line by line and
layer by layer. Metal particles are injected into a laser beam, where they are melted and
deposited onto a substrate as a miniature weld pool. The trace ofthe laser beam on the substrate
is driven by the definition ofCAD models until the desired net-shaped densified metal
component is produced.",,,,,,
"['Chang, R.', 'Starly, B.', 'Sun, W.', 'Culbertson, C.', 'Holtorf, H.', 'Gonda, S.']",2020-02-27T20:43:56Z,2020-02-27T20:43:56Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80104', 'http://dx.doi.org/10.26153/tsw/7125']",eng,2006 International Solid Freeform Fabrication Symposium,Open,physiologically-based pharmokinetic,Freeform Bioprinting of Liver Encapsulated in Alginate Hydrogels Tissue Constructs for Pharmacokinetic Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2f985cf-95e8-47de-9bb9-bf8682aaaebf/download,,"An in vitro model that can be realistically and inexpensively used to predict human response to
various drug administration and toxic chemical exposure is needed. By fabricating a microscale
3D physiological tissue construct consisting of an array of channels and tissue-embedded
chambers, one can selectively develop various biomimicking mammalian tissues for a number of
pharmaceutical applications, for example, experimental pharmaceutical screening for drug
efficacy and toxicity along with apprehending the disposition and metabolic profile of a
candidate drug. This paper addresses issues relating to the development and implementation of a
bioprinting process for freeform fabrication of a 3D cell-encapsulated hydrogel-based tissue
construct, the direct integration onto a microfluidic device for pharmacokinetic study, and the
underlying engineering science for the fabrication of a 3D microscale tissue chamber as well as
its application in pharmacokinetic study. To this end, a prototype 3D microfluidic tissue chamber
embedded with liver cells encapsulated within a hydrogel matrix construct is bioprinted as a
physiological in vitro model for pharmacokinetic study. The developed fabrication processes are
further validated and parameters optimized by assessing cell viability and liver cell phenotype, in
which metabolic and synthetic liver functions are quantitated.",,,,,,
"['Thomas, Albin', 'Kolan, Krishna C.R.', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2021-10-21T21:04:19Z,2021-10-21T21:04:19Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89448,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['freeform extrusion fabrication', 'bioactive glass scaffolds', 'titanium fibers', 'fiber reinforcement']",Freeform Extrusion Fabrication of Titanium Fiber Reinforced Bioactive Glass Scaffolds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea444e09-eb29-4399-b608-798da9287df8/download,University of Texas at Austin,"Although implants made with bioactive glass have shown promising results for bone
repair, their application in repairing load-bearing long bones is limited due to their low fracture
toughness and fairly fast degradation response in vivo. In this paper, we describe our
investigation of freeform extrusion fabrication of silicate based 13-93 bioactive glass scaffolds
reinforced with titanium fibers. A composite paste was prepared with 13-93 bioactive glass filled
with titanium fibers (~16 µm in diameter and aspect ratio of ~250) having a volume fraction of
0.4 vol. %. This paste was then extruded to fabricate scaffolds with an extrudate diameter of
about ~0.8 mm. The sintered scaffolds, with and without titanium fibers, had measured pore
sizes ranging from 400 to 800 µm and a porosity of ~50%. Scaffolds produced with 0.4 vol. %
titanium fibers were measured to have a fracture toughness of ~0.8 MPa•m1/2 and a flexural
strength of ~15 MPa. Bioactive glass scaffolds without titanium fibers had a toughness of ~ 0.5
MPa•m1/2 and strength of ~10 MPa. The addition of titanium fibers increased the fracture
toughness of the scaffolds by ~70% and flexural strength by ~40%. The scaffolds’
biocompatibility and their degradation in mechanical properties, in vitro were assessed by
immersing the scaffolds in a simulated body fluid over a period of one to four weeks.",,,,,,
"['Mason, Michael S.', 'Huang, Tieshu', 'Landers, Robert G.', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2020-02-28T20:43:36Z,2020-02-28T20:43:36Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80120', 'http://dx.doi.org/10.26153/tsw/7141']",eng,2006 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,"Freeform Extrusion of High Solids Loading Ceramic Slurries, Part I: Extrusion Process Modeling",Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4ca0ddf-50b3-4e3f-90a5-c12e6b67fd54/download,,"A novel solid freeform fabrication method has been developed for the manufacture of
ceramic-based components in an environmentally friendly fashion. The method is based on the
extrusion of ceramic slurries using water as the binding media. Aluminum oxide (Al2O3) is
currently being used as the part material and solids loading as high as 60 vol. % has been
achieved. This paper describes a manufacturing machine that has been developed for the
extrusion of high solids loading ceramic slurries. A critical component of the machine is the
deposition system, which consists of a syringe, a plunger, a ram actuated by a motor that forces
the plunger down to extrude material, and a load cell to measure the extrusion force. An
empirical, dynamic model of the ceramic extrusion process, where the input is the commanded
ram velocity and the output is the extrusion force, is developed. Several experiments are
conducted and empirical modeling techniques are utilized to construct the dynamic model. The
results demonstrate that the ceramic extrusion process has a very slow dynamic response, as
compared to other non-compressible fluids such as water. A substantial amount of variation
exists in the ceramic extrusion process, most notably in the transient dynamics, and a constant
ram velocity may either produce a relatively constant steady-state extrusion force or it may cause
the extrusion force to steadily increase until the ram motor skips. The ceramic extrusion process
is also subjected to significant disturbances such as air bubble release, which causes a dramatic
decrease in the extrusion force, and nozzle clogging, which causes the extrusion force to slowly
increase until the clog is released or the ram motor skips.",,,,,,
"['Mason, Michael S.', 'Huang, Tieshu', 'Landers, Robert G.', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2020-02-28T20:47:32Z,2020-02-28T20:47:32Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80121', 'http://dx.doi.org/10.26153/tsw/7142']",eng,2006 International Solid Freeform Fabrication Symposium,Open,solids loading ceramic slurry extrusion,"Freeform Extrusion of High Solids Loading Ceramic Slurries, Part II: Extrusion Process Control",Conference paper,https://repositories.lib.utexas.edu//bitstreams/d3102b2b-a7dd-412f-ba75-9e350117d86b/download,,"Part I of this paper provided a detailed description of a novel fabrication machine for high solids
loading ceramic slurry extrusion and presented an empirical model of the ceramic extrusion
process, with ram velocity as the input and extrusion force as the output. A constant force is
desirable in freeform extrusion processes as it correlates with a constant material deposition rate
and, thus, good part quality. The experimental results in Part I demonstrated that a constant ram
velocity will produce a transient extrusion force. In some instances the extrusion force increased
until ram motor skipping occurred. Further, process disturbances, such as air bubble release and
nozzle clogging that cause sudden changes in extrusion force, were often present. In this paper a
feedback controller for the ceramic extrusion process is designed and experimentally
implemented. The controller intelligently adjusts the ram motor velocity to maintain a constant
extrusion force. Since there is tremendous variability in the extrusion process characteristics, an
on-off controller is utilized in this paper. Comparisons are made between parts fabricated with
and without the feedback control. It is demonstrated that the use of the feedback control reduces
the effect of process disturbances (i.e., air bubble release and nozzle clogging) and dramatically
improves part quality.",,,,,,
"['Asiabanpour, Bahram', 'Melbye, Jerry', 'Melbye, Vicky', 'Jensen, Evan', 'Shaw, Joshua']",2021-09-23T22:01:17Z,2021-09-23T22:01:17Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88033', 'http://dx.doi.org/10.26153/tsw/14974']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['facial reproduction', 'forensic anthropology', 'skull prototyping', 'Laser Scanning']",Freeform Fabrication Assists Forensic Scientists in the Identification of Unknown Victims,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7e5a526e-bdc1-4935-9580-f07cd20b0c95/download,,"According to the International Homicide Investigators Association, there are currently over 40,000 unidentified
bodies being held in coroner‟s and medical examiner‟s offices across the United States. Over half are estimated to be
victims of homicide, and all are awaiting positive identification. One technique utilized by forensic anthropologists
to establish the identity of unknown skeletal or decomposed individuals is the use of facial reproduction. In facial
reproduction, soft tissue approximating muscle and skin is added to the skull in an attempt to reflect how the
individual looked during life. Soft tissue depths at specific locations (i.e., certain craniofacial landmarks) are known
and have been standardized according to an individual‟s sex, age, ancestry, and body type. For the most part, facial
reproduction is still accomplished manually by adding layers of soft clay to represent tissue on the actual skull of the
deceased individual. This method is quite time-consuming (often taking two or more weeks) and often not feasible
because the skull may be damaged, or the use of clay overlying the actual skull may destroy evidence. To overcome
these limitations, researchers have recently turned to Computed Tomography (CT scan) technology to generate CAD
files of unidentified skulls, which are then modeled and recreated with rapid prototyping machines. One limitation
of this method is that it is dependent on the initial CT scanning instrument, which is not portable and requires that
the unidentified remains be removed from their original storage sites (typically morgue coolers or crime scenes) to
the location where CT scanning instruments are available (often hospital or clinical settings). Because many of these
unidentified remains are either skeletonized or are in various stages of decomposition, the transport of these bodies
to locations with CT scanning machines is often not possible or permissible. In this paper, we first propose a new
method to rapid prototype skulls via stereolithography (STL) files generated by hand-held portable laser scanners, as
opposed to using CT scanning machines. These rapid prototypes can then be fabricated for facial reproduction,
negating the use of the actual skull, and not requiring the body be removed from its original location. Also, results
of the facial reproduction for an active case are presented. Secondly, we outline preliminary results of a new
computerized facial reproduction and superimposition method, which accurately models tissue depth and is not
dependent on the manual application of clay.",,,,,,
"['Malone, Evan', 'Rasa, Kian', 'Cohen, Daniel', 'Isaacson, Todd', 'Lashley, Hilary', 'Lipson, Hod']",2019-11-20T17:16:48Z,2019-11-20T17:16:48Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78487', 'http://dx.doi.org/10.26153/tsw/5572']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Structural-Electric,Freeform Fabrication of 3D Zinc-Air Batteries and Functional Structural-Electric Assemblies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/646535f1-76cd-4d03-af94-77749d2ec7a3/download,,"This paper reports on a fabrication platform and extensions to deposition-based processes
that permit freeform fabrication of three-dimensional functional assemblies with embedded
conductive wiring and power sources. Structure and joints are produced by fused deposition of
thermoplastics and deposition of elastomers. Conductive wiring is achieved by deposition of
various low-melting-point alloys and conductive pastes. Batteries based on zinc-air chemistry are
produced by deposition of zinc, electrolyte, and catalysts, with separator media and electrodes.
Details of the deposition processes are provided and several printed assemblies are demonstrated.","This work was supported in parts by the U.S. Department of Energy, grant DE-FG02-
01ER45902.",,,,,
"['Malone, Evan', 'Lipson, Hod']",2020-03-10T16:04:27Z,2020-03-10T16:04:27Z,9/5/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80219', 'http://dx.doi.org/10.26153/tsw/7238']",eng,2007 International Solid Freeform Fabrication Symposium,Open,electromechanical,Freeform Fabrication of a Complete Electrochemical Relay,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13fbb70e-d88a-4034-b228-7fbb3ede1495/download,,,,,,,,
"['Kyogoku, Hideki', 'Hagiwara, Masashi', 'Shinno, Toshifumi']",2021-09-30T13:22:46Z,2021-09-30T13:22:46Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88231', 'http://dx.doi.org/10.26153/tsw/15172']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'selective laser melting', 'aluminum alloy', 'freeform fabrication', 'Al-12Si alloy']",Freeform Fabrication of Aluminum Alloy Prototypes Using Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/07303ac8-a191-4ea0-8813-6821adeaf6d1/download,University of Texas at Austin,"In this study, a direct selective laser sintering/melting machine was designed and
constructed. The machine has a 50 W Yb-fiber laser, a galvanometer scanner and a powder
delivery and build system. It was confirmed that the machine works well. The fabrication
conditions of aluminum alloys were investigated using the machine. The optimum laser power,
scan speed and scan pitch were investigated by experiments. The effect of addition of metal
powder as additives on laser scanning process was investigated to fabricate the sound
laser-scanned body of aluminum alloys based on Al-12Si alloy. It was found that the smooth
single-scan track can be fabricated at lower laser power and higher scan speed by the addition of
a laser absorption material. An aluminum alloy prototype was successfully produced using
optimum laser scanning conditions.",,,,,,
"['Han, Li-Hsin', 'Mapili, Gazill', 'Chen, Shaochen', 'Roy, Krishnendu']",2020-03-10T15:05:28Z,2020-03-10T15:05:28Z,9/4/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80213', 'http://dx.doi.org/10.26153/tsw/7232']",eng,2007 International Solid Freeform Fabrication Symposium,Open,scaffolds,Freeform Fabrication of Biological Scaffolds by Projection Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/899be073-b465-41af-ae54-d1f011840323/download,,"This article presents a micro-manufacturing method for direct, projection printing of 3-
dimensional (3D) scaffolds for applications in the field of tissue engineering by using a
digital micro-mirror-array device (DMD) in a layer-by-layer process. Multi-layered
scaffolds are microfabricated using curable materials through an ultraviolet (UV)
photopolymerization process. The pre-patterned UV light is projected onto the photocurable
polymer solution by creating the “photomask” design with graphic software. Poly (ethylene
glycol) diacrylate (PEGDA), is mixed with a small amount of dye (0.3 wt %) to enhance the
fabrication resolution of the scaffold. The DMD fabrication system is equipped with a
purging mechanism to prevent the accumulation of oligomer, which could interfere with the
feature resolution of previously polymerized layers. The surfaces of the pre-designed,
multi-layered scaffold are covalently conjugated with fibronectin for efficient cellular
attachment. Our results show that murine marrow-derived progenitor cells successfully
attached to fibronectin-modified scaffolds.",,,,,,
"['Malone, Evan', 'Lipson, Hod']",2020-02-17T15:16:42Z,2020-02-17T15:16:42Z,9/1/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/80008', 'http://dx.doi.org/10.26153/tsw/7033']",eng,2004 International Solid Freeform Fabrication Symposium,Open,compact fabrication system,Freeform Fabrication of Electroactive Polymer Actuators and Electromechanical Devices,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0dfae166-ef2f-4e27-a047-faead286e5d0/download,,"In pursuit of the goal of producing complete electromechanical systems entirely via solid freeform fabrication, we are
developing a library of mutually compatible, functional, freeform elements. Several essential elements – actuation, sensing,
and control electronics - still remain to be incorporated into this library. Conducting polymers (CP) are a class of materials
which can be used to produce all of these functionalities. Meanwhile, research into actuatable “smart” materials has
produced other candidate materials for freeform fabricated actuators that are compatible with our library. We have
succeeded in manually producing air-operable actuators that have processing and operating requirements that are
compatible with our power source and mechanical component library elements. A survey of candidate actuator materials is
presented, experiments performed with two types of actuator materials are described, and complete SFF-producible actuator
devices are demonstrated.",,,,,,
"['Malone, Evan', 'Lipson, Hod']",2020-02-24T15:39:32Z,2020-02-24T15:39:32Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80085', 'http://dx.doi.org/10.26153/tsw/7106']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Freeform Fabrication of Ionomeric Polymer-Metal Composite Actuators,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e5c111e-d65f-4b55-a069-e5e76126c7c5/download,,"Ionomeric polymer-metal composite (IPMC) actuators are a type of soft electromechanically active material which offers
large displacement, rapid motion with only ~1V stimulus. IPMC’s are entering commercial applications in toys (Ashley
2003) and biomedical devices (Soltanpour 2001; Shahinpoor 2002; Shahinpoor, Shahinpoor et al. 2003; Soltanpour and
Shahinpoor 2003; Soltanpour and Shahinpoor 2004), but unfortunately they can only actuate by bending, limiting their
utility. Freeform fabrication offers a possible means of producing IPMC with novel geometry and/or tightly integrated with
mechanisms which can yield linear or more complex motion. We have developed materials and processes which allow us to
freeform fabricate complete IPMC actuators and their fabrication substrate which will allow integration within other
freeform fabricated devices. We have produced simple IPMC’s using our multiple material freeform fabrication system, and
have demonstrated operation in air for more than 40 minutes and 256 bidirectional actuation cycles. The output stress scaled
to input power is two orders of magnitude inferior to that of the best reported performance for devices produced in the
traditional manner, but only slightly inferior to devices produced in a more similar manner. Possible explanations and paths
to improvement are presented. Freeform fabrication of complete electroactive polymer actuators in unusual geometries,
with tailored actuation behavior, and integrated with other freeform fabricated active components, will enable advances in
biomedical device engineering, biologically inspired robotics, and other fields. This work constitutes the first
demonstration of complete, functional, IPMC actuators produced entirely by freeform fabrication.",,,,,,
"['Havener, Robin', 'Boyea, John', 'Malone, Evan', 'Bernards, Daniel', 'DeFranco, John', 'Malliaras, George', 'Lipson, Hod']",2020-03-09T13:36:50Z,2020-03-09T13:36:50Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80175', 'http://dx.doi.org/10.26153/tsw/7194']",eng,2007 International Solid Freeform Fabrication Symposium,Open,electrochemical transistors,Freeform Fabrication of Organic Electrochemical Transistors,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6c442b72-8949-4809-9da3-8b669cd362ef/download,,,,,,,,
"['Lipton, Jeffrey', 'Boban, Mathew', 'Hiller, Jonathan', 'Lipson, Hod']",2021-09-30T23:54:23Z,2021-09-30T23:54:23Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88299', 'http://dx.doi.org/10.26153/tsw/15240']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['cellular materials', 'stochastic foam', 'closed celled foams', 'viscous thread']",Freeform Fabrication of Stochastic and Ordered Cellular Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/16cef7be-06a8-4769-aa06-8d451023e6a8/download,University of Texas at Austin,"Cellular materials provide a unique challenge to SFF technology. Such materials
have unique properties of low mass, high strength, and good insulation properties.
To produce such cellular structures, SFF systems require a designed
microstructure with a feature size significantly lower than the resolution of the
process. In this paper, we examine means of producing stochastic foams using the
instability of a viscous thread and various methods for production of closed celled
foams. These techniques allow for the production of foams without the need for
pre-described cell structures. Such foams, when made from elastic materials can
act as novel actuating materials.",,,,,,
"Rotheroe, Kevin Chaite",2019-10-22T17:54:15Z,2019-10-22T17:54:15Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76325', 'http://dx.doi.org/10.26153/tsw/3414']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Optimized,The Freeform Fabrication of Structurally Optimized and Complexly Shaped Metal Tubular Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b21b6437-4fad-4a05-af0d-cdb96be5d51d/download,,"The service conditions of many structural frames composed of tubular metal components would
ideally warrant the use of high strength-to-weight ratio components with shapes and internal
geometries that respond to context-specific structural requirements. Commercially available and
emerging solid freeform fabrication technologies can be utilized to indirectly or directly
manufacture metal tubular structural components with optimizing features that cannot otherwise
be manufactured. The results of prototyping experiments demonstrating the viability and
potential of this application of additive manufacturing will be presented. This presentation will
discuss successful prototype 356 aluminum and 316 stainless steel internally reinforced freeform
tubular components manufactured indirectly using expendable patterns made by selective laser
sintering and 3D printing. The application of laser and metal powder based freeform fabrication
technologies that provide superior material properties will also be discussed, especially in terms
of requirements for multi-axis deposition and sophisticated path planning software, and the
implications of voxel- or layer-based functionally gradient materials.",,,,,,
"['Dcosta, D.J.', 'Sun, W.', 'Raghy-El, T.']",2019-10-10T17:20:51Z,2019-10-10T17:20:51Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76175', 'http://dx.doi.org/10.26153/tsw/3264']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Freeform Fabrication of Ti3SiC2 Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7882d446-272c-4065-ae71-8c037b730722/download,,"This paper introduces a three-stage process to fabricate highly dense Ti3SiC2 structures. The
properties of Ti3SiC2 material, the synthesis of the ceramic powder, the procedure involved in
the 3-stage fabrication process and the preliminary results on fabricating fully dense Ti3SiC2
structures are presented. The characterization and microstructure evaluation of the mechanical,
morphological and structural properties covering the compressive strength, Vickers micro
hardness, damage tolerance, thermal shock, shrinkage and porosity of Ti3SiC2 structures printed
using the 3-stage process are presented.",,,,,,
"['Berry, Megan E.', 'Malone, Evan', 'Lipson, Hod']",2020-02-21T16:07:27Z,2020-02-21T16:07:27Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80066', 'http://dx.doi.org/10.26153/tsw/7088']",eng,2005 International Solid Freeform Fabrication Symposium,Open,freeform fabricated circuits,Freeform Fabrication of Zinc Air Batteries with Tailored Geometry and Performance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/278cfb21-e669-437f-923f-3e495238c342/download,,"This work is focused on the freeform fabrication of complete zinc-air batteries. This
method of production gives great freedom in the geometry and construction of the battery,
allowing tailoring of the output characteristics, and the possibility of embedding a customized
battery within a larger integrated freeform fabricated device. Our batteries utilize a gelling agent to
prevent phase separation in the zinc anode and catalyst layers, permitting the use of nozzles down
to 1.3mm in diameter. Polyvinyl alcohol is utilized for the separator layer, which replaces the unprintable paper separator used in commercial batteries. With various freeform batteries we have
achieved a specific capacity of 60mAh/g of zinc, an average power 7.25mW, and continuous
service life of 63h, all with a load of 100 ohms. The specific capacity of our freeform batteries is
about 1 order of magnitude lower than that of commercial zinc-air batteries, although under
different test conditions. We have investigated the effect of cell active surface area on
performance for a cylindrical cell-geometry, and have produced a flexible, two-cell battery with
unusual geometry. The tailoring of performance and geometry possible with freeform fabrication
will be of great value in the design of optimized smart devices with unusual geometry, portable
electronics, and prototypes.",,,,,,
"['Leu, Ming C.', 'Adamek, Erik B.', 'Huang, Tieshu', 'Hilmas, Greg E.', 'Dogan, Faith']",2021-09-23T20:26:42Z,2021-09-23T20:26:42Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88022', 'http://dx.doi.org/10.26153/tsw/14963']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'SLS', 'zirconium diboride', 'freeform fabrication', 'mechanical engineering']",Freeform Fabrication of Zirconium Diboride Parts Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b80fd9f-f748-48da-ac1a-217cceb9f0fb/download,,"Using the Selective Laser Sintering (SLS) process, both flexural test bars and 3D
fuel injector components have been fabricated with zirconium diboride (ZrB2) powder.
Stearic acid was selected as the binder. Values of SLS process parameters were chosen
such that the green parts could be built with sharp geometrical features and that the
sintered parts could have good mechanical properties. After binder burnout and sintering,
the SLS fabricated ZrB2 test bars achieved 80% theoretical density, and the average
flexural strength of the sintered samples was 195 MPa. These values demonstrate the
feasibility of the SLS process for freeform fabrication of 3D parts with the ultra high
temperature ceramic.",,,,,,
"['Rock, Stephen J.', 'Gilman, Charles R.', 'Misiolek, Wojciech Z.', 'Walczyk, Daniel F.']",2018-11-09T16:32:09Z,2018-11-09T16:32:09Z,1996,Mechanical Engineering,doi:10.15781/T2T14V847,http://hdl.handle.net/2152/69932,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'Rapid Tooling', 'freeze molding']",Freeform Powder Molding for Rapid Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dab977f4-9c13-414b-bbe4-935a6e3a04ba/download,,"Tooling development can be quite time consuming and costly. Several iterations may be
required, and later product or process modifications may necessitate tooling redesign. Rapid
prototyping techniques capable of meeting the structural requirements of short-run and end-use
tooling will have a significant impact on the product development cycle. This paper presents a
technique for producing tooling using the Freeform Powder Molding process. Resulting tooling
can be made from a wide variety of readily available metal powders, and mechanical properties can
be tailored for customized tool design and fabrication. The example presented in this paper focuses
on the rapid production of tooling for sheet metal forming",,,,,,
"['Huang, T.S.', 'Doiphode, N.D.', 'Rahaman, M.N.', 'Leu, M.C.', 'Bal, B.S.', 'Day, D.E.']",2021-10-04T20:05:59Z,2021-10-04T20:05:59Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88332', 'http://dx.doi.org/10.26153/tsw/15271']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['freeze extrusion fabrication', 'bioactive glass', 'solid freeform fabrication', 'bone repair']",Freeze Extrusion Fabrication of 13-93 Bioactive Glass Scaffolds for Bone Repair,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bac9a092-59b5-4624-946b-d36df0aa4d27/download,University of Texas at Austin,"There is an increasing demand for synthetic scaffolds with the requisite biocompatibility,
internal architecture, and mechanical properties for the bone repair and regeneration. In this work,
scaffolds of a silicate bioactive glass (13-93) were prepared by a freeze extrusion fabrication
(FEF) method and evaluated in vitro for potential applications in bone repair and regeneration.
The process parameters for FEF production of scaffolds with the requisite microstructural
characteristics, as well as the mechanical and cell culture response of the scaffolds were
evaluated. After binder burnout and sintering (60 min at 700°C), the scaffolds consisted of a
dense glass network with interpenetrating pores (porosity ≈ 50%; pore width = 100−500 µm).
These scaffolds had a compressive strength of 140 ± 70 MPa, which is comparable to the
strength of human cortical bone and far higher than the strengths of bioactive glass and ceramic
scaffolds prepared by more conventional methods. The scaffolds also supported the proliferation
of osteogenic MLO-A5 cells, indicating their biocompatibility. Potential application of these
scaffolds in the repair and regeneration of load-bearing bones, such as segmental defects in long
bones, is discussed.",,,,,,
"['Huang, Tieshu', 'Mason, Michael S.', 'Hilmas, Gregory E.', 'Leu, Ming C.']",2020-02-20T20:00:26Z,2020-02-20T20:00:26Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80046,eng,2005 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'Fused Deposition of Ceramic']",Freeze-form Extrusion Fabrication of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03f6e416-3880-422f-9987-e54a84a76190/download,,"A novel, environmentally friendly solid freeform fabrication method called Freeze-form
Extrusion Fabrication (FEF) has been developed for the fabrication of ceramic-based
components. The method is based on deposition of ceramic pastes using water as the media.
The ceramic solids loading can be 50 vol. % or higher and initial studies have focused on the use
of aluminum oxide (Al2O3). The FEF system components and their interaction are examined,
and the main process parameters affecting part geometry defined. 3-D shaped components have
been fabricated by extrusion deposition of the ceramic paste in a layer-by-layer fashion. The
feasibility of this process has been demonstrated by building components having a simple
geometry, such as cylinders and solid or hollow cones. Hollow cones have also been fabricated
to demonstrate the ability to build structures with sloped walls.",,,,,,
"['Leu, Ming C.', 'Tang, Lie', 'Deuser, Brad', 'Landers, Robert G.', 'Hilmas, Gregory E.', 'Zhang, Shi', 'Watts, Jeremy']",2021-10-04T20:38:10Z,2021-10-04T20:38:10Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88342', 'http://dx.doi.org/10.26153/tsw/15281']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Freeze-form Fabrication', 'three-dimensional structures', 'graded composite materials', 'material composition']",Freeze-Form Extrusion Fabrication of Composite Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac0a470d-efc5-4ff5-adb5-cbce18006d4d/download,University of Texas at Austin,"A Freeze-form Extrusion Fabrication (FEF) process capable of making three-dimensional
(3D) parts and structures with graded composite materials is presented in this paper. The process
development includes the design and manufacture of a gantry machine with a triple-extruder
mechanism and the associated electronics hardware and computer software for fabricating
functionally graded parts from multiple aqueous pastes. A rheological behavior study with Al2O3
paste is performed to identify an efficient binder for transforming the paste into a pseudoplastic
with a high yield stress. A green part is first fabricated using the triple-extruder FEF machine in a
layer-by-layer manner with the desired material gradients. The green part is then freeze-dried, its
binder removed through a burnout process to obtain a brown part, and the final part obtained by
sintering. The final part is analyzed using energy dispersive X-ray spectroscopy (EDS) to
determine its material composition. The results demonstrate that the FEF process can be used to
fabricate functionally graded composite parts with pre-specified gradients.",,,,,,
"['Li, Ang', 'Thornton, Aaron S.', 'Deuser, Bradley', 'Watts, Jeremy L.', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Landers, Robert G.']",2021-10-06T20:07:25Z,2021-10-06T20:07:25Z,8/20/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88429', 'http://dx.doi.org/10.26153/tsw/15366']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['functionally-graded materials', 'Freeze-form Extrusion Fabrication', 'zirconium carbide', 'tungsten', 'ceramics', 'aerospace']",Freeze-Form Extrusion Fabrication of Functionally Graded Material Composites Using Zirconium Carbide and Tungsten,Conference paper,https://repositories.lib.utexas.edu//bitstreams/460f50c3-82b1-48f0-b710-f649f6a9a4b4/download,University of Texas at Austin,"Ultra-high-temperature ceramics are being investigated for future use in aerospace
applications due to their superior thermo-mechanical properties, as well as their oxidation
resistance, at temperatures above 2000°C. However, their brittleness makes them susceptible to
thermal shock failure. As graded composites, components fabricated as functionally-graded
materials (FGMs) can combine the superior properties of ceramics with the toughness of an
underlying refractory metal. This paper discusses the grading of two materials through the use of
a Freeze-form Extrusion Fabrication (FEF) system to build FGM parts consisting of zirconium
carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and W were
developed and utilized in the FEF process to fabricate test bars graded from 100%ZrC to 50%-W50%ZrC (volume percent). After FEF processing, the test bars were co-sintered at 2300°C and
characterized to determine their resulting density and microstructure. Four-point bending tests
were performed to assess the flexural strength of the test bars made using the FEF process,
compared to that prepared using conventional powder processing and isostatic pressing
techniques, for five distinct ZrC-W compositions. Scanning electron microscopy (SEM) was
used to examine the inner structure of composite parts built using the FEF process.",,,,,,
"['Fu, Q.', 'Jongprateep, O.', 'Abbott, A.', 'Dogan, F.']",2020-02-28T21:00:03Z,2020-02-28T21:00:03Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80122', 'http://dx.doi.org/10.26153/tsw/7143']",eng,2006 International Solid Freeform Fabrication Symposium,Open,ceramic composites,Freeze-Spray Processing of Layered Ceramic Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8e1aa70-cd05-46dd-b7cd-065ab0e2721d/download,,"Thermal gradients and associated stresses are critical in designing with ceramic
composites having low thermal conductivity. In order to reduce the stresses from thermal
gradients, compositional gradients are employed in designing of composite structures. This study
addresses development of freeze-spray process to fabricate layered ceramic structures with
controlled layer thickness and microstructural development. The composites were processed by
spraying of ceramic slurries with low binder content and relatively high solids loadings (up to 40
vol%) on a cooled substrate. The frozen parts were freeze-dried and sintered at elevated
temperatures. The relationship between microstructural development and thermal expansion
behavior of Al2O3 and Y2O3-stabilized ZrO2 functionally graded ceramic composites is
discussed.",,,,,,
"['Cullom, Tristan', 'Altese, Nicholas', 'Bristow, Douglas', 'Landers, Robert', 'Brown, Ben', 'Hartwig, Troy', 'Soine, David', 'Allen, Aimee', 'Barnard, Andrew', 'Blough, Jason', 'Johnson, Kevin', 'Kinzel, Edward']",2021-11-18T18:10:45Z,2021-11-18T18:10:45Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90451', 'http://dx.doi.org/10.26153/tsw/17372']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['frequency response', 'frequency domain', 'melt pool recoil pressure', 'metal parts', 'additive manufacturing']",Frequency Domain Measurements of Melt Pool Recoil Pressure Using Modal Analysis and Prospects for In-Situ Non-Destructive Testing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77498550-1a14-43c8-ba19-cdc7dc8ce2f4/download,University of Texas at Austin,"Fielding Additively Manufactured (AM) parts requires evaluating both the part’s
geometry and material state. This includes geometry that may be optically hidden. Both the
geometry and material state affect the vibration response of the parts and modal analysis
(identifying natural frequencies) has been shown to be effective for at least simple geometries
using ex-situ methods (shaker table and impact hammer excitations). This paper investigates
evaluation of the frequency response of metal parts inside the build chamber using the process
laser to excite the parts during printing (Renishaw AM250). Vibrations in the part are measured
with accelerometers connected to the build plates and used to track the response during printing
as during pauses between layers. The laser is modulated at different frequencies and focused
onto specific targets to precisely extract the response from individual parts on the build plate.
These results are compared to numerical models for metal parts of different geometries and with
different material states.","This work was funded by the Department of Energy’s Kansas City
National Security Campus which is operated and managed by Honeywell Federal Manufacturing
Technologies, LLC under contract number DE-NA0002839.",,,,,
"['Allen, Aimee', 'Johnson, Kevin', 'Blough, Jason', 'Barnard, Andrew', 'Hartwig, Troy', 'Brown, Ben', 'Soine, David', 'Cullom, Tristan', 'Bristow, Douglas', 'Landers, Robert', 'Kinzel, Edward']",2021-11-18T18:02:57Z,2021-11-18T18:02:57Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90449', 'http://dx.doi.org/10.26153/tsw/17370']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['defect identification', 'frequency inspection', 'defects', 'additive manufacturing']",Frequency Inspection of Additively Manufactured Parts for Layer Defect Identification,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2a5710fd-1bdb-444b-a89a-9649ec153ec9/download,University of Texas at Austin,"Additive manufactured (AM) parts are produced at low volume or with complex
geometries. Identifying internal defects is difficult as current testing techniques are not optimized
for AM processes. The goal of this paper is to evaluate defects on multiple parts printed on the
same build plate. The technique used was resonant frequency testing with the results verified
through Finite Element Analysis. From these tests, it was found that the natural frequencies
needed to detect the defects were higher than the excitation provided by a modal hammer. The
deficiencies in this range led to the development of other excitation methods. Based on these
results, traditional methods of resonant part inspection are not sufficient, but special methods can
be developed for specific cases.","This work was funded by the Department of Energy’s Kansas
City National Security Campus which is operated and managed by Honeywell Federal
Manufacturing Technologies, LLC under contract number DE-NA0002839.",,,,,
"['Johnson, Kevin', 'Blough, Jason', 'Barnard, Andrew', 'Hartwig, Troy', 'Brown, Ben', 'Soine, David', 'Collum, Tristan', 'Kinzel, Edward', 'Bristow, Douglas', 'Landers, Robert']",2021-11-16T15:14:54Z,2021-11-16T15:14:54Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90309', 'http://dx.doi.org/10.26153/tsw/17230']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['internal defect', 'frequency response inspection', 'dynamic measurement', 'additive manufacturing']",Frequency Response Inspection of Additively Manufactured Parts for Defect Identification,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e21fd76-bdfe-4869-a4c9-5769796bf840/download,University of Texas at Austin,"The goal of this paper is to evaluate internal defects in AM parts using dynamic
measurements. The natural frequencies of AM parts can be identified by measuring the response
of the part(s) to a dynamic input. Different excitation methods such as a modal impact hammer or
shakers can be used to excite the parts. Various methods exist to measure the parts’ responses and
find the natural frequencies. This paper will investigate the use of Doppler lasers, accelerometers
and Digital Image Correlation (DIC). The parts evaluated in this work include sets of parts that
are still attached to the AM build plate, this makes the identification of a faulty part much more
difficult as parts on a build plate interact with each other as well as the build plate complicating
the responses. Several approaches to these issues will be presented based on the above listed
response measurements.",,,,,,
"['Kulkarni, N.P.', 'Tandra, G.', 'Liou, F.W.', 'Sparks, T.E.', 'Ruan, J.']",2021-09-29T17:53:19Z,2021-09-29T17:53:19Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88201', 'http://dx.doi.org/10.26153/tsw/15142']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['fuel cells', 'clean energy', 'additive manufacturing', 'fuel cell components']",Fuel Cell Development using Additive Manufacturing Technologies - A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/042d0db0-994e-4e0c-be5a-78933ae51376/download,University of Texas at Austin,"Fuel cells are being perceived as the future clean energy source by many developed
countries in the world. The key today for clean power is the reliance of fuel cells not only
to power automobiles but also for residential, small commercial, backup power etc.
which calls for production on a large scale. Additive manufacturing is perceived as a way
to develop cost effective fuel cells. It imparts flexibility to design different kinds of fuel
cells along with reduction in material wastage. This paper deals with the review of
additive manufacturing processes for research and development of fuel cell components,
such as synthesizing and prototyping new materials for fuel cell components, fuel cell
system design and prototyping, designing well sealed fuel cells, bridging from fuel cell
design to manufacturing tooling, etc.",,,,,,
"['Niino, T.', 'Yamada, H.']",2020-02-13T21:09:28Z,2020-02-13T21:09:28Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79981', 'http://dx.doi.org/10.26153/tsw/7006']",eng,2004 International Solid Freeform Fabrication Symposium,Open,stereolithography,Full-Densification of SLS Parts by Re-Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68180da6-8976-4839-833f-3f550e3d58d7/download,,"Among commercially available rapid prototyping processes, SLS is the most effective in
terms of adaptability of various materials. However, rapid prototyped parts by the process are
always porous and the physical properties of the parts are different from dense parts which is to
be used in final product. This paper introduces a post process that can densify SLS processed
plastic parts to almost 100%. An SLS processed polystyrene part is densified and, resultantly, a
much stronger and transparent part is obtained.",,,,,,
"['Hiller, Jonathan D.', 'Lipson, Hod']",2021-09-28T18:48:14Z,2021-09-28T18:48:14Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88151', 'http://dx.doi.org/10.26153/tsw/15092']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['recycling', 'multi-material printing', 'recyclable material', 'reusable material']",Fully Recyclable Multi-Material Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b333053-4a90-460b-8d37-f9eb4cee1122/download,University of Texas at Austin,"Recycling is often a costly and inefficient process, particularly for objects
composed of multiple integrated materials. Here, we demonstrate a freeform
fabrication system that prints with fully reusable physical voxels and minimal
recycling effort. This new paradigm of digital (discrete) matter enables any
number of materials to be printed together in any configuration. The individual
voxels may then be reclaimed at will by dissolving the bonds holding the structure
together. Coupled with a compatible voxel sorting process, we demonstrate
multiple generations of freeform fabricated objects using the same physical
material. This opens the door to a flexible desktop fabrication process in which
3D multi-material objects are fully recyclable and re-usable with minimal
infrastructure.",,,,,,
"['Micali, Maxwell K.', 'Dornfeld, David']",2021-10-26T17:51:25Z,2021-10-26T17:51:25Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89538,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['CAM', 'additive', 'process planning', 'accessibility', 'configuration space']",Fully Three-Dimensional Toolpath Generation for Point-Based Additive Manufacturing Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a3afd149-7a01-4ed8-90fa-865c1c4e468f/download,University of Texas at Austin,"While additive manufacturing and 3D printing achieved notoriety for their abilities to
manufacture complex three-dimensional parts, the state of the art is not truly three-dimensional.
Rather, the process plans for the majority of these machines rely on a stack of discretized, two-dimensional layers, which results in parts with stair-stepped surfaces, as opposed to being
smooth and freeform. This work proposes a change to the 2.5D paradigm by using a
configuration space approach to enable toolpath planning in a full three-dimensional space,
allowing movements beyond planar slices. Algorithms are also presented to compute toolpaths
on non-planar regions. Since the toolpaths take part and machine geometries into account, they
are guaranteed to be collision-free. These techniques are relevant to many additive
manufacturing technologies, including fused deposition modeling (FDM), directed energy
deposition (DED), material jetting, and nozzle-based variants. The result of implementing nonplanar toolpaths is smoother, more continuous part surfaces.",,,,,,
"['Ge, Wenjun', 'Lin, Feng', 'Guo, Chao']",2021-10-20T21:15:36Z,2021-10-20T21:15:36Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89362,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Selective Melting', 'gradient structures', 'Ti-6Al-4V', 'γ-TiAl']",Functional Gradient Material of Ti-6Al-4V and γ-TiAl Fabricated by Electron Beam Selective Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/beade2e9-8699-4780-a628-c16e07e6c98d/download,University of Texas at Austin,"Additive Manufacturing (AM) technologies are very promising in fabricating
functionally graded materials. Electron Beam Selective Manufacturing (EBSM) is one widely
used AM technology capable of fabricating a variety of materials especially titanium alloys.
Previous studies on EBSM process were focused on the manufacturing of one single material. In
this study, a novel EBSM process capable of building gradient structures with dual metal
materials was developed. Ti6Al4V powders and Ti47Al2Cr2Nb powders were used to fabricate
Ti3Al/TiAl and Ti6Al4V/Ti3Al dual metal structures. The chemical compositions, microstructure
and micro-hardness of the dual material samples were investigated employing Optical
Microscope (OM), Scanning Electronic Microscope (SEM), Electron Probe Micro-Analyzer
(EPMA). Results showed that the thickness of the transition zone was about 300μm. The
transition zone was free of cracks, and the chemical compositions exhibited a staircase-like
change. The microstructure and chemical compositions in different regions were studied. Microhardness was affected by the microstructure. The microstructures turned out to be full lamellar at
the TiAl region and basket-weave structure at the Ti3Al and Ti6Al4V region.",,,,,,
"['Fessler, J.', 'Nickel, A.', 'Link, G.', 'Prinz, F.', 'Fussell, P.']",2018-12-06T21:19:32Z,2018-12-06T21:19:32Z,1997,Mechanical Engineering,doi:10.15781/T22F7KB48,http://hdl.handle.net/2152/71430,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['material properties', 'SDM']",Functional Gradient Metallic Prototypes through Shape Deposition Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b379205-01fb-4e42-9c5f-384cde18a093/download,,"Stanford's SDM laser deposition system has been recently improved to enable the
deposition of functionally graded metals through the use of powder mixing. While Shape
Deposition Manufacturing has always had the capability to produce multimaterial artifacts, powder
mixing enables the deposition ofsingle layers in which material properties can be smoothly varied
without discrete interfaces between dissimilar materials. It has been shown that certain materials
will completely mix during deposition and form alloys which exhibit material properties
intermediate to those ofthe constituent feed powders. To date, oxidation and hardness have been
effectively controlled through appropriate mixing of powders. Functional gradient material
deposition has been exploited to construct an advanced injection molding tool which transitions
from Invar in the center to stainless steel on the outside. The resulting tool exhibited minimal
distortion from thermal stress and excellent exterior corrosion resistance.",,,,,,
"['Choi, Jae-Won', 'Yamashita, Masaki', 'Sakakibara, Jun']",2021-09-29T17:12:01Z,2021-09-29T17:12:01Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88191', 'http://dx.doi.org/10.26153/tsw/15132']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['phacoemulsification', 'cataract surgery', 'irrigation', 'swirl', 'microstereolithography']",Functional Micro/Macro Fabrication Combining Multiple Additive Fabrication Technologies: Design and Development off an Improved Micro-Vane Phacoemulsifier used in Cataract Surgery,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02aa22eb-e77f-4a39-b35b-03570a99c080/download,University of Texas at Austin,,"Microstereolithography (µSL) technology can fabricate complex, three-dimensional (3D) microstructures,
although µSL has difficulty producing macrostructures with micro-scale features. There are potentially
many applications, where 3D micro-features can benefit the overall function of the macrostructure.
One such application has been recently identified in cataract surgery where a medical device, called a
coaxial phacoemulsifier, is inserted into the eye through a relatively small incision and used to break
the lens apart while removing the lens pieces and associated fluid from the eye through a small tube.
In order to maintain the eye at a constant pressure, the phacoemulsifier also includes an irrigation
solution that is injected into the eye during the procedure. It has been reported, however, that the
impinging flow from the irrigation solution on the corneal endothelial cells in the inner eye damages
these cells during the procedure. As a result, we are exploring methods for reducing flow velocities
during this procedure, and have designed a complex, 3D micro-vane within a sleeve that introduces
swirl into the irrigation solution, and thus, produces a flow with rapidly dissipating flow velocities.
However, the fabrication of the sleeve could not be accomplished using µSL alone, and thus, a two-part design was accomplished where a sleeve with the micro-vane was fabricated with µSL and a
threaded fitting used to attach the sleeve to the phacoemulsifier was fabricated using an Objet Eden
333 rapid prototyping machine. The new combined device was tested in a water container using
particle image velocimetry, and the results showed an ejection of the irrigation fluid through the micro-vane in three different radial direction. It is believed that this new device will reduce damage to
endothelial cells during cataract surgery and significantly improve patient outcomes from this procedure.
This unique application demonstrates the utility of combining µSL with a macro rapid prototyping
technology for fabricating a real macro-scale device with functional, 3D micro-scale features that could
not be fabricated using conventional methods.",,,,,
"['Noecker II, Fredrick F.', 'DuPont, John N.']",2019-10-23T14:48:10Z,2019-10-23T14:48:10Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76751', 'http://dx.doi.org/10.26153/tsw/3840']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Net Shaping,Functionally Graded Copper-Steel Using Laser Engineering Net Shaping� Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/491350cf-ddce-4ae3-8270-9571a617f9be/download,,"Laser Engineered Net Shaping (LENS) is an emerging Solid Freeform Fabrication
(SFF) process capable of producing fully dense metallic parts with complex shapes directly from
a computer-aided drawing (CAD) without the need for molding or tooling. The LENS process
also shows promise in producing components with graded compositions. One potential
application is the production of steel – copper die casting materials. Copper is currently
deposited on dies made out of steel to enhance thermal management, however, difficulties can
occur at the Fe-Cu interface, such as, a large solidification temperature range in the Fe-Cu
system (which can cause solidification cracking), formation of undesirable phases, and
differences in coefficient of thermal expansion. The current research goal is to develop LENS
processing parameters to optimize the deposition of functionally graded steel - Copper alloy.
Dilution control experiments were carried out to determine the cracking susceptibility of Steel -
Cu alloys of varying compositions. The resulting microstructures were characterized by various
microscopy techniques. The influence of composition on the resultant cracking susceptibility
and microstructure will be discussed. This information is useful for successful deposition of
crack-free copper layers onto steel for die casting applications.",,,,,,
"['Pulugurtha, Syamala R.', 'Newkirk, Joseph', 'Liou, Frank', 'Chou, Hsin-Nan']",2021-09-29T14:24:32Z,2021-09-29T14:24:32Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88181', 'http://dx.doi.org/10.26153/tsw/15122']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['functionally graded materials', 'laser metal deposition', 'intermixing', 'cracking', 'dilution', 'LMD', 'FGMs']",Functionally Graded Materials by Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61513a20-555c-4286-83fb-343d5a503d6f/download,University of Texas at Austin,"Fabrication of functionally graded materials (FGMs) by laser metal deposition (LMD) has the
potential to offer solutions to key engineering problems over the traditional metal-working
techniques. But the issues that need to be addressed while building FGMs are intermixing in the
layers and cracking due to the residual stresses. This paper is to present the study of the effect of
process parameters (laser power and travel speed) on the degree of dilution between the substrate
(or, previous layer) and powder material for few metallurgical systems.",,,,,,
"['Chartoff, Richard', 'McMorrow, Brian', 'Lucas, Pierre']",2019-11-21T17:44:42Z,2019-11-21T17:44:42Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78542', 'http://dx.doi.org/10.26153/tsw/5598']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Nano-Composites,Functionally Graded Polymer Matrix Nano-Composites by Solid Freeform Fabrication: A Preliminary Report,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a461372-d44b-4b5f-bc52-767cbbde9d1e/download,,"A research program has been initiated to develop a Solid Freeform Fabrication (SFF)
technology for combining nanosized particulate or fiber reinforcements with a photocurable
thermoset matrix resin in order to produce functional graded composites. The composites that are
being studied initially are optical components filled with nano-phase ceramic particles that form
gradient refractive index lenses (GRIN). The Solid Freeform Fabrication (SFF) method employs
an ink-jet deposition (IJD) process to form the composites. The IJD process has the advantage of
incorporating nano-reinforcements into a low viscosity matrix resin that is relatively easy to
process and rapidly photocures to produce functional polymeric parts. It also has the advantage
that major modifications to the basic SFF processing methodology are not necessary.
 The emphasis in the program is on demonstrating the feasibility of this approach for
fabrication of gradient refractive index lenses (GRIN), which are flat instead of the traditional
spherical lens geometry. As a result these lenses will be less costly to produce than conventional
curved lenses. SFF is an ideal technique for meeting the needs of GRIN lens fabrication because
changes in composition can be made from layer to layer and even within each layer, allowing for
the introduction of compositional and structural gradients. Thus it has the potential for creating
the spatial material distributions required for designing computer optimized, custom made GRIN
lenses. Integral to the SFF process are computer design procedures that specify the exact
material deposition patterns that need to be employed in order to optimize the performance of the
GRIN lens.
The optical nano-composites will serve as a model system that we will use to work out
the many challenges for implementing a viable SFF polymer composites technology. We then
will make use of the information obtained and lessons learned from the work on optical
composites and extend the development to structural composites that incorporate nano-particulate
clays and carbon nanofibers.",,,,,,
"['Park, Seok-Min', 'Crawford, Richard H.', 'Beaman, Joseph J.']",2019-03-12T16:32:06Z,2019-03-12T16:32:06Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73598', 'http://dx.doi.org/10.26153/tsw/740']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['FGM', 'SFF']",Functionally Gradient Material Design and Modeling Using Hypertexture for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e935b0b4-c871-45fe-9b1e-1fd9677342d7/download,,"SFF technologies have the potential to become manufacturing process that are capable of producing
parts that have not been feasible by other techniques. The fabrication of Functionally Gradient Material
(FGM) is one of the possible candidate. It is critical.to provide three dimensional material gradient data
in the solid model to fabricate FGM. The approach is to model spatially varying material density
distribution on implicit solid geometry using a hypertexturing scheme and a procedural volumetric
modeling. It is essentially an extension of procedural solid texture synthesis, which has been effectively
used to model cloud, gas, and flow stream. It will save the amount of information storage especially
when the gradient pattern is repeating. Geometric operation becomes convenient since the material data
are linked to the geometry only by the reference surfaces.",,,,,,
"['Park, Seok-Min', 'Crawford, Richard H.', 'Beaman, Joseph J.']",2019-09-23T16:34:03Z,2019-09-23T16:34:03Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75958', 'http://dx.doi.org/10.26153/tsw/3057']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Fabrication,Functionally Gradient Material Representation by Volumetric Multi-Texturing for Solid Freeform Fabrication 350,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6c0c3aa-d80e-4f90-af60-e56091629224/download,,"In order to fabricate parts from Functionally Gradient Materials (FGM) by layered manufacturing methods, the SFF community needs a method to represent material distributions in solid models. Gradient material distribution requires accurate and systematic representation, and must be compatible with existing geometric data. This paper presents a method, called Volumetric Multi Texturing, to represent a three dimensional density gradient by exploiting hypertexturing and volumetric density functions. This method utilizes procedural and implicit methods to design/acquire density information. The implicit procedural approach, as opposed to an input database, allows users to interactively create and modify the design patterns without explicitly changing the values stored in the database. Further, it promises convenience in process planning, and efficiency in data storage and computation time. The theoretical approach, design procedure, and tool path generation for fabrication of an example part are presented in the paper. The design procedure presented is based on specifying the material gradient by surface modification.",We gratefully acknowledge the financial support of the National Science Foundation under grant number DMI9618034.,,,,,
"['Gasdaska, C.', 'Clancy, R.', 'Ortiz, M.', 'Jamalabad, V.', 'Virkar, Anil', 'Popovitch, Dragan']",2019-03-01T17:35:05Z,2019-03-01T17:35:05Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73517', 'http://dx.doi.org/10.26153/tsw/667']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['microstructures', 'CTE']",Functionally Optimized Ceramic Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db26107e-5d8a-4802-a109-9eddb6320e30/download,,"The feasibility of using the Fused Deposition of Ceramics (FDC) process to rapidly fabricate
functional quality advanced ceramic components has been demonstrated multiple extrusion
heads enable the deposition of spatially engineered ceramic microstructures on the scale of 250
um. This unique capability of FDC allows components to be built with combinations of materials
and properties that are difficult or impossible to produce using conventional fabrication
processes. Some concepts will be presented, along with examples of multiple material laminates
produced using FDC. Strength data will be presented which demonstrates the performance
improvement possible using spatially engineered microstructures.",,,,,,
"['Bunnell, D.E.', 'Das, S.', 'Bourell, D.L.', 'Beaman, J.B.', 'Marcus, H.L.']",2018-11-08T15:45:04Z,2018-11-08T15:45:04Z,1995,Mechanical Engineering,doi:10.15781/T26D5PX0B,http://hdl.handle.net/2152/69893,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['surface tension', 'liquid-vapor surface tension', 'LPS']",Fundamentals of Liquid Phase Sintering During Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2221e141-b608-4c8d-a6f4-625acc6825db/download,,"One of the advantages of the Selective Laser Sintering (SLS) process is that a variety of materials
can be processed. However, the goal of being able to produce fully dense metal parts with no post
processing has been elusive. Using Selective Laser Sintering to produce metal parts with full
density without post processing poses a challenge since both the processing conditions and the
metal system must be controlled. This article describes two metallurgical mechanisms by which
loose metal powder beds could be sintered to nearly full density using a scanning laser beam. The
mechanisms are particle rearrangement during liquid phase sintering (LPS) and in-situ infiltration.
Some of the particles, when heated by the laser radiation, melt and form a liquid. Ifthis liquid has
certain physical properties (e.g., low viscosity and high surface tension) and wets the other solid
particles, then the SLS process can in theory produce dense layers by either mechanism. The
purpose of this study is to determine the process and material selection parameters required to
achieve fully dense parts during direct Selective Laser Sintering of metal.",,,,,,
"['Bunnell, D.E.', 'Bourell, D.L.', 'Marcus, H.L.']",2018-10-03T18:32:54Z,2018-10-03T18:32:54Z,1994,Mechanical Engineering,doi:10.15781/T2DR2PT81,http://hdl.handle.net/2152/68674,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['liquid phase sintering', 'selective laser sintering', 'sinter powder particles']",Fundamentals of Liquid Phase Sintering Related to Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8083318e-0629-4a68-8c61-c22e20ea66cf/download,,"Liquid phase sintering is one of the underlying principles that must be
modeled and understood when the Selective Laser Sintering (SLS) process is
used. This paper describes the initial studies being conducted to measure
surface tension of metal alloys used for SLS. A low melting point solder was
used to verify the wetting balance and pendant drop techniques and equipment
for determining surface tension. The liquid-solid, liquid-vapor, and solid
vapor surface tension of 80 Sn - 20 Pb solder on mild steel was determined to
be 245, 417, and 662 dynes/cm.",,,,,,
"['Chatham, Camden A.', 'Talley, Samantha J.']",2024-03-25T22:15:47Z,2024-03-25T22:15:47Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124316', 'https://doi.org/10.26153/tsw/50924']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PBF/LB', 'crystallization', 'additive manufacturing']",Fundamentals of Polymer Crystallization in Laser Powder Bed Fusion for New Material Screening,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5977508-a28c-4223-b14a-d46dffb4fc48/download,University of Texas at Austin,"Although laser powder bed fusion (PBF/LB) was one of the first industrially viable additive
manufacturing (AM) methods for end-use part production, polyamides remain grossly dominant
at both the commercial- and research scale. The research community continues to develop and
refine “rapid screening” methods for evaluating the suitability of new polymers for PBF/LB. The
so-called “SLS Process Window,” which is the difference between melting and crystallization
temperature measured at 10 K min-1 as originally outlined in the patent literature, is perhaps the
most often reported screening method. Although perhaps appropriate as part of a larger study, the
simplistic guidelines put forth by the “SLS Process Window” are not sufficiently scientifically
rigorous to understand how crystallization kinetics affects successful 3D printing. The common
understanding of the SLS Process Window omits details from published theories of polymer
crystallization. as evidenced by published assumptions and methods in PBF/LB process modeling
papers. The authors explain polymer crystallization in the PBF/LB context and propose replacing
the “process window” with crystallization halftime and physical gelation for new material
screening. These measurements better represent behavior critical for ensuring a lengthy
coexistence of solid powder and molten polymer affecting warp-free parts.",,,,,,
"Jacobs, Paul F.",2018-04-19T18:14:11Z,2018-04-19T18:14:11Z,1992,Mechanical Engineering,doi:10.15781/T24M91T5H,http://hdl.handle.net/2152/64400,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'Research & Development', 'photons', 'rapid prototyping']",Fundamentals of Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03e894c8-0920-41fe-a42c-9e91539cebc4/download,,"It has only been a little over four years since the introduction
of the first StereoLithography system, the SLA-1. From early 1988
until J.une 1992 over 300 SLA-1, SLA-250, SLA-190 and SLA-500 units have
been sold by 3D Systems. These machines, currently operating in 20
countries on five continents, amount to about 90 percent of all the
rapid prototyping systems now in use.",,,,,,
"['Hauser, C.', 'Childs, T. H. C.', 'Badrossamay, M.']",2020-02-14T15:36:50Z,2020-02-14T15:36:50Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79986', 'http://dx.doi.org/10.26153/tsw/7011']",eng,2004 International Solid Freeform Fabrication Symposium,Open,bed temperature,Further Developments in Process Mapping and Modelling in Direct Metal Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a9ee21c-52d1-4e46-91a6-fefc794493cd/download,,"This paper advances previous reported work on the mapping and modelling of single
tracks and layers produced in powder beds of tool steel and stainless steel powders by a CO2
laser. For single tracks it reports on predicted and simulated track masses. It validates the
simulations, including the use of absorption close to 1.0 when cylindrical tracks are formed. It
also reports on melt pool temperature calculations and estimated melt pool dimensions which are
used, in conjunction with bed physical properties, to explain why the single tracks form as either
continuous with a crescent shape cross-section, continuous with an elliptical section,
discontinuously irregularly broken, discontinuously balled or only partially melted as scan
speeds and laser powers change. It then extends its scope, experimentally, to consider effects of
scan spacing on single layer formation.",,,,,,
"['Obielodan, J.O.', 'Stucker, B.E.']",2021-09-28T20:19:03Z,2021-09-28T20:19:03Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88173', 'http://dx.doi.org/10.26153/tsw/15114']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['multi-material fabrication', 'ultrasonic consolidation', 'bond quality']",Further Exploration of Multi-Material Fabrication Capabilities of Ultrasonic Consolidation Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3715e4aa-84ae-4933-b861-1cbd14dec151/download,University of Texas at Austin,"The increasing interest in engineering designs involving parts with multiple materials,
and function specific members has placed more demand for technologies to fabricate such parts.
This work discusses results of further exploration of multi-material freeform fabrication using
ultrasonic consolidation. Various combinations of materials, including Titanium, Silver,
Tantalum, Aluminum, Molybdenum, stainless steel, Nickel, Copper, and MetPreg have been
studied. Some were found to be effective as a suitable intermediate layer between difficult to join
materials. Elemental Boron particles were added in situ between selected materials to modify the
bonding characteristics. Microstructures of deposits were studied to evaluate bond qualities.
Results show evidence of good bonds between various combinations of materials, thus
illustrating increasing potential for multi-material freeform fabrication using ultrasonic
consolidation.",,,,,,
"['Yang, Li', 'Lassell, Austin', 'Perez Vilhena Paiva, Gustavo']",2021-10-21T21:54:03Z,2021-10-21T21:54:03Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89452,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['electropolishing', 'Ti6Al4V', 'electron beam melting', 'process parameters']",Further Study of the Electropolishing of Ti6Al4V Parts Made via Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a64df3ed-1413-4c68-ab0d-1b8819e4f929/download,University of Texas at Austin,"In this study, the effect of various parameters including the voltage, current, polishing time,
temperature and electrode spacing on the electropolishing quality of Ti6Al4V samples made via
electron beam melting was investigated using specialty designed research setups. The
relationships between these process parameters and the surface roughness of the parts were
established experimentally.",,,,,,
"['Simonelli, M.', 'Tse, Y.Y.', 'Tuck, C.']",2021-10-06T20:13:25Z,2021-10-06T20:13:25Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88430', 'http://dx.doi.org/10.26153/tsw/15367']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'Ti-6Al-4V', 'microstructural features', 'texture analysis']",Further Understanding on Ti-6Al-4V Selective Laser Melting Using Texture Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc466bf5-a961-4534-ab43-561258e47bae/download,University of Texas at Austin,"Selective laser melting (SLM) has shown to be an attractive manufacturing route to
produce Ti-6Al-4V components. In the present study, the relation between the texture
evolution and a particular set of process parameters adopted for the production of near fully
dense components was investigated. The aim of this investigation was to understand which
microstructural features can be tailored during the SLM production. The microstructural
characterisation of the as-built components was carried out using various microscopy
techniques including optical, scanning electron and transmission electron microscopy. Phases
and texture analysis were carried out using backscattered electron imaging and electron
backscattered diffraction. It was found that the components consist of ’ martensitic phase
precipitated from prior β columnar grains. It was found that the α’ martensitic laths develop
from the parent β grains following the Burgers orientation relationship. The texture of the
prior β phase was calculated and compared to the measured α’ texture. It was found that at
each layer processing the α’ texture is retained and variant selection takes place. The
observed microstructural details will be discussed in relation to the SLM parameters.",,,,,,
"['Mireles, Jorge', 'Espalin, David', 'Roberson, David', 'Zinniel, Bob', 'Medina, Francisco', 'Wicker, Ryan']",2021-10-06T22:00:03Z,2021-10-06T22:00:03Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88457', 'http://dx.doi.org/10.26153/tsw/15394']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling for metals', '3-dimensional metallic structures', 'electronics', 'electronic circuitry']",Fused Deposition Modeling of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f5230cc-455e-4ec0-80d8-04a5ed694d34/download,University of Texas at Austin,"Studies have been conducted to improve previous work performed in developing a Fused
Deposition Modeling for metals (FDMm) system used for applications in electronics and
fabrication of 3-dimensional metallic structures. A FDM 3000 system was modified to achieve
controlled deposition of eutectic Bi58Sn42 and non-eutectic Sn60Bi40 materials. Toolpath
command modifications were required to achieve controlled deposition of metals. Results are
presented which include a redesigned metal deposition head, computer modeling of fluid flow,
and finally examples of the successful deposition of metal alloys. Additionally, FDMm-fabricated metal samples were prepared and analyzed using optical and scanning electron
microscopy. Controlled deposition of metals using FDMm allows for parts that can be used for
jigs and fixtures, electroforming mandrels, encapsulation molds, dies, electronic joining
applications, as well as printing 3-dimensional electronic circuitry.",,,,,,
"['Espalin, David', 'Arcaute, Karina', 'Rodriguez, David', 'Medina, Frank', 'Posner, Matthew', 'Wicker, Ryan']",2021-09-29T17:19:01Z,2021-09-29T17:19:01Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88192', 'http://dx.doi.org/10.26153/tsw/15133']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['polymethylmethacrylate', 'fused deposition modeling', 'reconstructive surgery', 'scaffolds', 'mechanical properties']",Fused Deposition Modeling of Polymethylmethacrylate for Use in Patient-Specific Reconstructive Surgery,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66e3a74d-b5f7-4b48-8081-1bbdbd5e40e4/download,University of Texas at Austin,"facial reconstruction and as bone cement and antibiotic-impregnated spacers in
orthopaedics. The polymerization of PMMA in-situ causes tissue necrosis and other
complications due to the long surgical times associated with mixing and shaping the PMMA.
PMMA is a thermoplastic acrylic resin suitable for extrusion in FDM thus 3D anatomical models
can be fabricated prior to surgery directly from medical imaging data. The building parameters
required for successful FDM fabrication with medical-grade PMMA filament (1/16ӯ) were
developed using an FDM 3000. It was found that a liquefier and envelope temperature of 235ºC
and 55ºC, respectively, as well as increasing the model feed rate by 60%, were necessary to
properly and consistently extrude the PMMA filament. Scaffolds with different porosities and
fabrication conditions (tip wipe frequency and layer orientation) were produced, and their
compressive mechanical properties were examined. Results show that both the tip wipe
frequency (1 wipe every layer or 1 wipe every 10 layers) and layer orientation (transverse or
axial with respect to the applied compressive load) used to fabricate the scaffolds, as well as the
porosity of the scaffold had an effect on the mechanical properties. The samples fabricated with
the high tip frequency had a larger compressive strength and modulus (Compressive strength: 16
± 0.97 vs. 13 ± 0.71 MPa, Modulus: 370 ± 14 vs. 313 ± 29 MPa, for samples fabricated in the
transverse orientation with 1 tip wipe per layer or 1 tip wipe per 10 layers, respectively). Also,
the samples fabricated in the transverse orientation had a larger compressive strength and
modulus than the ones fabricated in the axial orientation (Compressive strength: 16±0.97 vs.
13±0.83 MPa, Modulus: 370±14 vs. 281±22 MPa, for samples fabricated with 1 tip wipe per
layer, in the transverse and axial orientation, respectively). Overall, the compressive strain for
the samples fabricated with the four different conditions ranged from 8 – 12%. In regards to the
porosity of the samples, in general, the stiffness, yield strength and yield strain decreased when
the porosity increased (Compressive strength: 12±0.71 – 7±0.95 MPa, Modulus: 248±10 –
165±16 MPa, Strain: 7±1.5 – 5±1% for samples with a porosity ranging from 55 – 70%). The
successful FDM fabrication of patient-specific, 3D PMMA implants with varying densities,
including the model of a structure to repair a cranial defect and the model of a femur, was
demonstrated. This work shows that customized structures with varying porosities to achieve
tailored properties can be designed and directly fabricated using FDM and PMMA.",,,,,,
"['Onagoruwa, Seyi', 'Bose, Susmita', 'Bandyopadhyay, Amit']",2019-10-10T17:36:04Z,2019-10-10T17:36:04Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76178', 'http://dx.doi.org/10.26153/tsw/3267']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Ceramics,Fused Deposition of Ceramics (FDC) and Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a49849fd-b841-4a0b-bb10-6944145dbc40/download,,"Fabrication of functional ceramics and composites has been attempted using fused deposition of
ceramics process. In this work, first a polypropylene (PP) binder system has been developed for
the FDM. The PP binder system was mixed with ceramic powders and then extruded in the form
of filament for the FDC. Controlled porosity ceramic parts were directly fabricated using a FDM
1650 machine with mullite, fused silica and titania powder loaded green filaments. The parts
were then binder removed and sintered. Some of the porous parts were then infiltrated in Al
metal to form the metal-ceramic composites. This article discusses feedstock development, part
fabrication and methods to improve the quality of parts during processing.",,,,,,
"['Agarwala, M.K.', 'Bandyopadhyay, A.', 'Weeren, R. van', 'Langrana, N.A.', 'Safari, A.', 'Danforth, S.C.', 'Jamalabad, V. R.', 'Whalen, P. J.', 'Donaldson, R.', 'Pollinger, J.']",2018-11-14T17:59:59Z,2018-11-14T17:59:59Z,1996,Mechanical Engineering,doi:10.15781/T2B854376,http://hdl.handle.net/2152/70253,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'FDC', 'structural ceramics']",Fused Deposition of Ceramics (FDC) for Structural Silicon Nitride Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c922d9f2-3bfc-4d2d-abce-054b97f6beaf/download,,"Fused Deposition of Ceramics is aI! SFF tec~que based on comm~rcial FDMTM ~echno.logy, f?r
fabrication of structural and functIonal cerannc components. ThIS study descnbes, ill detail,
process improvements made in pre-FDC, FDC, and post-FDC fabrication steps to achieve
functional properties in commercial GS-44 silicon nitride ?omponents. . Microstructural
characterization of sintered FDC parts reveals microstructures simllar to convennonally processed
silicon nitride material. Mechanical properties of FDC processed silicon nitride bend bars and
toughness samples were evaluated. These property evaluation studies demonstrate that mechanical
properties similar to commercial GS-44 silicon nitride materials can be achieved using FDC. The
study also describes results achieved on fabrication of complex components from silicon nitride
using FDC.",,,,,,
"['Agarwala, M.K.', 'Weeren, R. van', 'Bandyopadhyay, A.', 'Whalen, P.J.', 'Safari, A.', 'Danforth, S.C.']",2018-11-14T20:13:24Z,2018-11-14T20:13:24Z,1996,Mechanical Engineering,doi:10.15781/T2NK36Q96,http://hdl.handle.net/2152/70261,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'FDC', 'fabrication of polymer']",Fused Deposition of Ceramics and Metals : An Overview,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc19efbc-f09b-4ba0-9fd9-a49f495fb713/download,,"Fused Deposition of Ceramics (FDC) and Metals (FDMet) are SFF techniques, based on
commercial FDMTM technology, for rapid fabrication of functional ceramic and metal parts from
powderlbinder materials. This work demonstrates the possibility of applying FDC and FDMet to a
variety of ceramic and metal particulate systems for fabrication of components/parts/devices for
wide ranging applications such as tooling, investment casting cores and shells, structural and
functional components, etc. Several particulate ceramic and metal systems have been explored for
FDC and FDMet. The particulate systems explored vary in particle size from nano-crystalline
(WC-Co) to coarse (>100 Jlm Si(2) particles. The material systems explored for FDC and FDMet
vary from conventional ceramic and metal systems such as Si02 and stainless steel to advanced
materials such as Si3N4 and PZT. FDC and FDMet of such a variety of material systems using a
commercial FDMTM system has been made feasible by development of a unique series of binders,
as well as optimized FD processing, binder removal techniques and sintering conditions.",,,,,,
"['Clancy, R.', 'Jamalabad, V.', 'Whalen, P.', 'Bhargava, P.', 'Dai, C.', 'Rangarajan, S.', 'Wu, S.', 'Danforth, S.', 'Langrana, N.', 'Safari, A.']",2018-11-29T20:35:44Z,2018-11-29T20:35:44Z,1997,Mechanical Engineering,doi:10.15781/T2416TJ9C,http://hdl.handle.net/2152/70341,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['filament buckling', 'compounded material']",Fused Deposition of Ceramics: Progress Towards a Robust and Controlled Process for Commercialization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03426575-cdc6-4b8a-87fd-b239597c1f0f/download,,"The feasibility of using the Fused Deposition ofCeramics (FDC) process to rapidly fabricate
functional quality advanced ceramic components has been demonstratedl
-
5
. This direct
manufacturing technique, by eliminating the need for costly tooling, dramatically reduces
functional prototype development time. This makes it suitable for small quantity production runs
and complex parts. The move from 'feasibility"" to a robust, reliable commercial fabrication
tool requires that every aspect ofthe manufacturing be understood and brought under control.
An overview ofthe five basic process steps in FDC: batch compounding, filament fabrication,
fused deposition, binder burnout and sintering will be presented in light ofthis drive toward a
robust process. Tools such as Statistical Process Control and Experimental Design techniques
are being used to monitor, improve, and stabilize each step and sub-process. Hardware and
software modifications have been made to the FD machine to effect the required changes. This
paper will identify the remaining technical barriers to commercialization and our progress in
addressing these issues.",,,,,,
"['Benza, Donald', 'Chatham, Camden A.', 'Baker, Jonathan', 'Johnson, Devin']",2024-03-25T22:17:48Z,2024-03-25T22:17:48Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124317', 'https://doi.org/10.26153/tsw/50925']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['polymer', 'fusion', 'additive manufacturing']",Fused Filament Fabrication of Polymer Blends with in situ Layerwise Chemical Modifications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/001d89dc-9ce8-4a6d-8727-a4d3bdbf0d91/download,University of Texas at Austin,"The layerwise paradigm of additive manufacturing advertises voxel level control over both
geometry and material properties of parts although the latter is difficult to achieve. Recently the
Savannah River National Laboratory has demonstrated a new technique for voxel level material
property control via layerwise surface chemical modification of polycarbonate homopolymer with
UV and ozone during manufacturing. This technique can be utilized to modify each respective
phase of a blended polymer feedstock to increase chemical similarity in preparation for potential
in situ interphase crosslinking. Successful crosslinking of dissimilar polymers during
manufacturing could allow for further voxel level material property control than modification of a
homopolymer could allow. Test feedstock comprised of melt mixed polycarbonate and polystyrene
homopolymers, an immiscible polymer blend, were printed in an atmosphere containing ozone
and UV light. FTIR measurements indicate both phases of the blend may be modified
simultaneously in situ to form new oxygen functional groups, increasing chemical similarity.
Calorimetric and thermomechanical characterization show no indicators of increased
compatibilization due to the treatment. Uniaxial tension to failure experiments demonstrates
minimal loss of mechanical properties as the blend phase to phase interfacial properties dominates
the behavior despite the chemical modifications. Future work will focus on understanding the
complex relationships between configurable processing parameters (layer height, print speed,
temperature, etc), reaction site creation density, and blend degradation prior to further modification
while identifying a suitable crosslinker to improve mechanical and thermal properties of the blend.",,,,,,
"['Zhang, J.', 'Van Hooreweder, B.', 'Ferraris, E.']",2021-12-01T21:49:45Z,2021-12-01T21:49:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90626', 'http://dx.doi.org/10.26153/tsw/17545']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['fused filament fabrication', 'moon', 'heat transfer']",Fused Filament Fabrication on the Moon,Conference paper,https://repositories.lib.utexas.edu//bitstreams/21c9a496-868b-4511-a58d-a1513a8c5981/download,University of Texas at Austin,"Additive manufacturing (AM) techniques possess the capabilities to rapidly produce complex
and customised parts, typically in low-volume and with reduced material us- age and preparation
tools . These attributes magnify their indispensability when the availability of materials and
equipment is limited. It can be such a case for off-Earth manufacturing, e.g. in manned lunar
explorations. This article presents a preliminary discussion on the possibility of performing fused
filament fabrication (FFF) on the Moon from the perspective of heat transfer in printed parts. It
makes use of experimen- tal data and simulations to quantify the significance of each heat
transfer mechanism taking place during printing. The quantification then enables us to
investigate how the lunar environment affects the cooling in the printed parts. Finally, FFF on
the Moon is predicted to be feasible. Yet, apparent differences in the process window and types
of applications are pointed out as compared with the counterpart printing activities on the Earth.
The full paper may be found in a special issue of the TMS publication JOM, March 2022.",,,,,,
"['Valenti, Justin D.', 'Bartolai, Joseph', 'Yukish, Michael A.']",2024-03-26T17:04:49Z,2024-03-26T17:04:49Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124376', 'https://doi.org/10.26153/tsw/50984']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['G-wing', 'software', 'wings', 'material extrusion', 'additive manufacturing']",G-WING: A NOVEL SOFTWARE TOOL FOR TOOLPATH-CENTRIC DESIGN OF WINGS FOR MATERIAL EXTRUSION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b46e629-7b8e-4c5b-bd83-16be4c2a82c4/download,University of Texas at Austin,"A novel software tool for the design of small aircraft wings to be fabricated with material
extrusion is presented where the key requirement of the tool is to minimize the time from
identified need to realized capability. The tool, named G-Wing, uses rapid design algorithms
based on lifting line theory to determine the outer-mold line of the wing based on desired
aerodynamic behavior. The resulting wing shape and flight-load distribution are given to a
structural design algorithm to determine the internal structure of the wing based on both
expected flight loads and manufacturing constraints. Finally, manufacturing instructions in
the form of G-Code are created directly from the wing shape and internal structure. This
process removes explicit geometric modeling and slicing from the critical design path and
directly converts airfoil coordinates to perimeter G-Code points, minimizing the introduction
of geometric error. This process has been used to design and fabricate multiple small aircraft
wings that have successfully flown. G-Code for an example wing section is shown to be
lighter and require less build time compared to G-Code generated by a standard CAD-slicing
toolchain.",,,,,,
"['Smith, Steven L', 'Paul, Jerri']",2018-11-09T14:42:02Z,2018-11-09T14:42:02Z,1996,Mechanical Engineering,doi:10.15781/T2765B14Q,http://hdl.handle.net/2152/69921,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['Raytheon-Waco', 'Rapid Prototyping', 'high-volume production']",Gaining Competitive Advantage By Using Rapid Prototyping in Aircraft Modification,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68b4d9ba-bdae-43b2-ad29-43f9b373ede2/download,,"Raytheon-Waco (formerly Chrysler Technologies Airborne Systems) is an aircraft
modification facility in Waco, TX, specializing in military, executive, and head-of-state aircraft
modifications. Raytheon-Waco has over 25 years of aircraft modification experience, and is a
leading contractor for major US and foreign government programs that require system design,
airframe modification, installation, flight testing, and post-delivery technical and logistical
support. Current programs at Raytheon-Waco include foreign government Head-of-State widebody
aircraft modifications consisting ofluxury interiors, secure communications, and airframe
modifications, and US and foreign military aircraft modifications involving electronics,
communications, avionics, and airframe modifications.
The aircraft modification industry is highly competitive, with a variety of very competent
companies constantly trying to increase market share and move into new markets. RaytheonWaco
has focused primarily on military communications and transport aircraft, and Head-ofState
wide-body aircraft. Due to increasing competition and customer cost-conscientiousness,
Raytheon-Waco is working to reduce cost and cycle time while maintaining its reputation for
delivering on time and within budget. There is also movement into other markets, such as lowercost
wide-body executive aircraft.
Raytheon-Waco is currently transitioning to a paperless design process, with the ultimate
goal of performing all design, analysis, manufacturing, and aircraft installation from CAD
models without requiring paper drawings. Increased use of electronic models will also allow
more parallel processes to be performed, eliminating many of the sequential design steps
currently required. Among the steps that will be performed in parallel will be detailed design,
manufacturing and installation planning, technical publications, and design analysis. Without
improved initial designs, parallel work will only lead to increased rework and wasted effort.
Rapid prototyping is a key factor in reducing risks associated with concurrent processes, and its
benefits are critical to efforts to reduce the cost and schedule of future aircraft modifications.",,,,,,
"['Harrison, Shay', 'Costa, Chris F.', 'Jakubenas, Kevin J.', 'Crocker, James E.', 'Marcus, Harris L.']",2018-11-29T21:53:28Z,2018-11-29T21:53:28Z,1997,Mechanical Engineering,doi:10.15781/T2Z893132,http://hdl.handle.net/2152/70347,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SALD', 'TMS']",Gas Phase SFF Control System for Silicon Nitride Deposition by SALD/SALDV,Conference paper,https://repositories.lib.utexas.edu//bitstreams/243c803b-c8e4-4757-bced-da51633afe05/download,,": A closed-loop laser scanning and temperature control system has been developed for
SALD/SALDVI. Temperature control is especially important in SALD/SALDVI because
temperature plays a defining role in both composition and deposition rate. The control system for
SALD/SALDVI is presented which provides .STL file interpretation, real time temperature
control, and laser response modeling, all on a PC. This control system was utilized with the
SALD/SALDVI techniques for depositing silicon nitride. Characteristics of ShN4 fabricated
shapes are discussed, including composition, morphology, and electrical properties.",,,,,,
"['Weiss, Clayton', 'Marcus, Harris L.']",2021-10-05T14:00:38Z,2021-10-05T14:00:38Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88374', 'http://dx.doi.org/10.26153/tsw/15313']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['solid freeform', 'ceramic materials', 'Selective Area Laser Deposition']",Gas Phase Solid Freeform for Fabrication of Three-dimensional Ceramic Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aff0062f-298c-4ff4-81a7-63ad423ab451/download,University of Texas at Austin,"Solid free form of ceramic materials can be achieved by deposition from the gas phase.
The Selective Area Laser Deposition, or SALD, technique can be utilized to make ceramic
depositions with a uniform chemical composition. In order to make all classes of ceramics,
including carbides, nitrides, and oxides, selection of a precursor is an essential step. Often the
correct precursor for the deposition requires a special environment, namely, one that can be
uniformly heated. System design for a heated deposition chamber is discussed as well as
preliminary tests of the system functionality. Silicon Carbide depositions were performed as a
means of evaluating system parameters.",,,,,,
"['Maxwell, James', 'Pegna, Joseph', 'Hill, Eric']",2018-10-05T17:30:49Z,2018-10-05T17:30:49Z,1995,Mechanical Engineering,doi:10.15781/T2M61C83P,http://hdl.handle.net/2152/68719,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['3D mode of pyrolytic LCVD', 'SALD', 'photolytic']",Gas-Phase Laser-Induced Pyrolysis of Tapered Microstructures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f9930f84-2914-41ac-b48f-f72356b5b9aa/download,,"Gas-phase Selective Area Laser Deposition (SALD) is a useful freeform fabrication
tool for the prototyping of simple three-dimensional microstructures.
Using this method, slender graphite and nickel rods of various
diameters were grown from ethylene and nickel tetracarbonyl, respectively.
By varying the laser power during growth, tapered cone-like structures were
also generated. Rod diameters and material morphology were correlated with
the SALD process parameters to demonstrate the mechanisms through which
steady-state rod growth occurs--and through which it can be controlled.
Rods, and other similar microstructures, have many useful applications, and
are preliminary building blocks for further modelling and development of
the SALD process as a micromachining tool.
Keywords: Laser chemical vapor deposition, LCVD, SALD, 3-dimensional
growth, micro fabrication, rapid prototyping, micro electro mechanical systems,
pyroiysis, graphite, nickel, rods, cone.",,,,,,
"['Harrison, S.', 'Marcus, H.L.']",2019-02-26T20:12:40Z,2019-02-26T20:12:40Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73493', 'http://dx.doi.org/10.26153/tsw/643']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['ceramic parts', 'surface material']",Gas-Phase Selective Area Laser Deposition(SALD) Joining of SiC Tubes with SiC Filler Materia,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1ac616e-dedb-4ea0-9660-20c07c9da43d/download,,"The laser-driven, gas-phase based SFF technique for joining together ceramic
components with ceramic filler material, known as Selective Area Laser Deposition(SALD)
Joining, was utilized in fabricating joined silicon carbide structures. Specifically, silicon
carbide tubes were 'welded' together by depositing silicon carbide from a gas phase reaction.
Two different precursor environments were examined, one a tetramethylsilane/hydrogen mixture
and the other composed of methyltrichlorosilane. The quality of the joints were examined by
bend tests and hermeticity measurements. In addition, the composition and morphology of the
silicon carbide deposit was studied and is discussed here",,,,,,
"['Crocker, James E.', 'Shaw, Leon L.', 'Marcus, Harris L.']",2019-09-23T15:25:31Z,2019-09-23T15:25:31Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75935', 'http://dx.doi.org/10.26153/tsw/3034']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Fabrication,GAS-PHASE SOLID FREEFORM FABRICATION OF SiC CERMETS USING SALDVI,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e1072cfa-797c-4c22-8afc-ec68198113ad/download,,"Selective Area Laser Deposition Vapor Infiltration (SALDVI) is an experimental solid freeform fabrication (SFF) technique aimed at the direct fabrication of ceramic and ceramic/metal structures and composites. SALDVI uses a layer-by-layer approach in which powders are infiltrated with solid material deposited from gas precursors by chemical vapor deposition (CVD) using laser heating. Experiments have been performed with CO2 and Nd:YAG lasers using the silicon carbide forming gas precursor Si(CH3)4 and Cu, Mo, and Ni metal powders. The microstructure of the resulting SiC/metal cermets was investigated in relation to the processing history. In some cases, the formation of intermetallic silicide phases was observed",,,,,,
"['Carter, W.T.', 'Emo, D.J.', 'Abbott, D.H.', 'Bruck, C.E.', 'Wilson, G.H.', 'Wolfe, J.B.', 'Finkhousen, D.M.', 'Tepper, A.', 'Stevens, R.G.']",2021-10-19T15:27:10Z,2021-10-19T15:27:10Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89299,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['crowdsourcing', 'collaborative engineering', 'additive manufacturing', 'GE', 'aircraft engine bracket']",The GE Aircraft Engine Bracket Challenge: An Experiment in Crowdsourcing for Mechanical Design Concepts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7f500f42-3fbb-4c90-9484-6a21a1d48063/download,University of Texas at Austin,"An emerging international engineering design trend has resulted from widespread use of
social media: a large number of people are engaged in collaborative engineering design activities
to build their design expertise through interaction with other designers, to compete for
recognition or prizes, or simply for the enjoyment of doing so. The term “crowdsourcing” was
introduced in 2005 and implies soliciting contributions from a large group of people, usually an
online community, in order to get a broad perspective from various points of view. This
community-generated creativity is contrary to conventional practice in most manufacturing
companies, which prefer tight control of engineering designs and practices because they
represent key intellectual property and know-how. Recognizing that crowdsourcing represents a
potential resource, GE embarked on an experiment to see how a for-profit company might
benefit from soliciting new design approaches from this non-traditional source. The design of a
specific part, an aircraft engine bracket, was released to an online community of engineers with
an invitation to submit improved designs in an open competition. Entrants were encouraged to
consider additive manufacturing as the fabrication method. Hundreds of designers submitted
concepts and some achieved 80% reduction in weight.",,,,,,
"['Jamalabad, Vikram R.', 'Whalen, Philip J.', 'Pollinger, John', 'Agarwala, Mukesh K', 'Danforth, Stephen C.']",2018-11-09T15:06:52Z,2018-11-09T15:06:52Z,1996,Mechanical Engineering,doi:10.15781/T2ZP3WK5K,http://hdl.handle.net/2152/69923,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['Solid free-form fabrication', 'Molds', 'Gelcasting']",Gelcast Molding with Rapid Prototyped Fugitive Molds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b43c356-5845-431c-ba93-c4692a0a8cc0/download,,"A technique for the rapid manufacture ofceramic components has been developed
using rapid prototyping to generate molds for the required components. The process
entails the fabrication offugitive tooling using rapid prototyping techniques from which
ceramic articles are formed using gelcasting. In the gelcasting process, the mold cavities
are filled with a fluid suspension of ceramic powder which sets to a solid form through
the polymerization of gelling additives and application of heat. The mold is carefully
removed by dissolution or heat treatment leaving the intact gelcast part. The ""green""
gelcast part is subsequently dried and sintered to full density. Computer aided
manufacturing of the tooling using solid freeform fabrication techniques allows for
complex shapes to be manufactured with minimal tooling cost. The technique is idealfor
the manufacture of ceramic parts in small batch conditions or for prototyping of
functional parts in design cycles. Cost and time reduction of a magnitude can be
achieved.",,,,,,
"['Pan, Tan', 'Karnati, Sreekar', 'Liou, Frank']",2021-11-10T22:33:16Z,2021-11-10T22:33:16Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90194', 'http://dx.doi.org/10.26153/tsw/17115']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['general rules', 'build process', 'process planning', 'powder bed fusion']",General Rules for Pre-Process Planning in Powder Bed Fusion System - A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/888dc1ff-8be7-4c64-aa67-4e7cdcfcc2bb/download,University of Texas at Austin,"Powder bed fusion (PBF) is one of the current additive manufacturing techniques that can
fabricate almost fully dense functional metal components. Through a layer by layer fabrication
methodology, complex geometries to meet the requirements of aerospace, automotive,
biomedicine industries, etc. can be produced. The success of a build largely depends on having a
flawless pre-process planning, including build orientation selection, support structure optimization,
process parameter chosen, etc., which closely relates to the quality of the final products. Geometric
inaccuracy and poor surface quality can occur due to a bad build plan. This review presents the
crucial general planning rules for the build process. Build orientation selection, support structure
optimization, and process parameter chosen in terms of residual stress reduction are the mainly
concerns, which have been surveyed and discussed. The overall objective of this work is to help
setup build plans that can ensure precise dimensions and high surface quality among the built
components.",,,,,,
"['Rock, Stephen J.', 'Wozny, Michael J.']",2018-04-19T18:25:51Z,2018-04-19T18:25:51Z,1992,Mechanical Engineering,doi:10.15781/T2C53FJ2V,http://hdl.handle.net/2152/64406,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['STL de facto', 'CAD models', 'Computer aided designs']","Generating Topological Information from a ""Bucket of Facets""",Conference paper,https://repositories.lib.utexas.edu//bitstreams/36f2a0f7-abb5-4a59-8ce4-930053e024b5/download,,"The STL de facto data exchange standard for Solid Freefonn F*brication represents
CAD models as a collection of unordered triangular planar facels. No topological
connectivity information is provided; hence the term ""bucket of facet."" Such topological
information can, however, be quite useful for performing model validity checking and
speeding subsequent processing operations such as model slicing. lfhis paper discusses
model topology and how to derive it given a collection of unordered tri,ngular facets which
represent a valid model.",,,,,,
"['Porter, Conor', 'Carter, Fred', 'Kozjek, Dominik', 'Cardona, Andrea', 'Mogonye, Jon-Erik', 'Ehmann, Kornel', 'Cao, Jian']",2023-01-31T14:17:48Z,2023-01-31T14:17:48Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117369', 'http://dx.doi.org/10.26153/tsw/44250']",eng,2022 International Solid Freeform Fabrication Symposium,Open,ALSI10MG L-PBF,Generation and Analysis of AlSi10Mg L-PBF Single Track Data Set Enabling Deeper Process Insights,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ba6384b-9cdc-4474-a72e-5ef6ba6c1f91/download,,"The stability of the melt pool in Laser Powder Bed Fusion (L-PBF), especially with 
process perturbations, is a key factor underpinning the success of additively manufactured 
components. In metal Additive Manufacturing (AM), single tracks are widely used to verify and 
validate simulation and process models. This work describes the creation of a holistic L-PBF 
single track data set incorporating a large domain of process conditions for AlSi10Mg. The 352 
single tracks are characterized through a series of high throughput methods including white light 
interferometry, automated microstructure analysis, and in-situ high-frequency (up to 200 kHz) 
coaxial melt pool monitoring. This data constitutes a large database of process parameters, high-
resolution measurements, and geometry information for data driven analysis, including machine 
learning. In one approach this data is used to correlate track shape and melt pool characteristics 
to in-situ measurements.",,,,,,
"['Rui, Wang', 'Haiou, Zhang', 'Guilan, Wang', 'Shangyong, Tang', 'Runsheng, Li']",2021-11-03T20:15:51Z,2021-11-03T20:15:51Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89921,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['deposition path', 'deposition region', 'quadrilateral meshes']",Generation of Deposition Parts and Quadrilateral Meshes in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1dedfef4-48e4-4bff-9009-82b997f2cde3/download,University of Texas at Austin,"In wire arc welding Additive Manufacturing (WAAM), filling paths have a strong
influence on the deformation of fabricated part. Many researchers employ FEM to
analyze the effects of different filling strategies. However, they mainly majored in
regular simple path (e.g. line and circle).This paper presents the method to generate
meshes in deposition region of complicated path which can be used in FEM. First, the
contour offset path and skeleton path is introduced. Then, the deposition region of
each path is created by offsetting the paths inward and outward. Afterwards,
quadrilateral meshes are constructed within each region. Deposition region is
approximated by meshes.",,,,,,
"['Neumeister, A.', 'Himmelhuber, R.', 'Temme, T.', 'Stute, U.']",2020-02-27T19:25:04Z,2020-02-27T19:25:04Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80093', 'http://dx.doi.org/10.26153/tsw/7114']",eng,2006 International Solid Freeform Fabrication Symposium,Open,micro system technology,Generation of Micro Mechanical Devices Using Stereo Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c91948aa-26c1-41f3-8d43-40f59453cc30/download,,"A high resolution machining setup for creating three-dimensional precision components from a
UV-curable photo-resin has been developed. By using frequency-converted diode-pumped solid
state lasers, functional micro-mechanical devices are directly fabricated in a successive layer-bylayer fashion. Within this paper, the direct generation of micro assemblies having
moving components without further assembly of parts will be presented. The micro system
design is based on user-defined 3D-CAD data and will completively be built up within the
fabrication cycle. By using specially developed μSL materials with suitable properties for micromechanical parts, the development from Rapid Prototyping towards Rapid Production of small
series is intended.",,,,,,
"['Bertoldi, M.', 'Yardimci, M. A', 'Pistor, C. M', 'Guceri, S.I', 'Danforth, S. C.']",2019-02-28T18:36:08Z,2019-02-28T18:36:08Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73509', 'http://dx.doi.org/10.26153/tsw/659']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SML', 'SSL']",Generation of Porous Structures Using Fused Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/14d84492-a977-42e4-9eea-bb10d0817568/download,,"The Fused Deposition Modeling process uses hardware and software machine-level
language that are very similar to that of a pen-plotter. Consequently, the·use of patterns with
poly-lines as basic geometric features, instead of the current method based on filled polygons
(monolithic models), can increase its efficiency.
In the current study, various toolpath planning methods have been developed to fabricate
porous structures. Computational domain decomposition methods can be applied to the physical
or to slice-level domains to generate structured and unstructured grids. Also, textures can be
created using periodic tiling of the layer with unit cells (squares, honeycombs, etc). Methods
'based on curves include fractal space filling curves and.change of effective road width Within a
layer or within a continuous curve. Individual phases can also be placed in binary compositions.
In present investigation, a custom software has been developed and implemented to
generate build files (SML) and slice files (SSL) for the above-mentioned structures, demonstrating the efficient control ofthe size, shape, and distribution ofporosity.",,,,,,
"['Logozzo, Paula', 'Palomino, Donald', 'Meiszner, Abraham', 'Borijin, Bodia', 'Wang, Andrew', 'Watkins, Ryan', 'Li, Bingbing']",2023-02-24T14:41:09Z,2023-02-24T14:41:09Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117523', 'http://dx.doi.org/10.26153/tsw/44403']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Generative Design', 'Design for Additive Manufacturing', 'Satellite Optical Tracker  Mount']",Generative Design for Additive Manufacturing of Satellite Optical Tracker Mount,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ddba2f64-dfbd-41c3-aa38-8df3c11a004d/download,,"The organic and intricate nature of machine generated parts is problematic during the 
manufacturing phase, resulting in high costs and slow production with traditional manufacturing 
techniques. Additive manufacturing has been explored and approved as the potential solution for 
fabricating complex geometry and organic lattice structures. With the advances in topology 
optimization and generative design, design for additive manufacturing (DAM) allows users to 
generate numerous, high-quality design alternatives that are lighter and stronger than traditionally 
designed parts. This study addresses the process of designing and load testing a satellite optical 
instrument mounting bracket using the generative design and simulation capabilities of Autodesk 
Fusion 360. The workflow pipeline begins with the creation of generative design studies for the 
instrument bracket in accordance with the design criteria outlined in the optical instrument design 
challenge, where it is then thermally load tested using finite element analysis (FEA) in Fusion 360 
and analyzed for its mechanical behavior.",,,,,,
"Boivie, Klas",2019-11-21T18:45:50Z,2019-11-21T18:45:50Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78567', 'http://dx.doi.org/10.26153/tsw/5623']",eng,2003 International Solid Freeform Fabrication Symposium,Open,SLS Steel,A Generic System for Homogenous SLS Steel Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9dc137f1-c0c9-428c-8622-bc3711b142de/download,,"A generic approach to a variety if different steel materials for SLS based application has
been examined. This approach is based on a base steel alloy powder mixed with a powder blend
of much smaller particles. The powder blend is designed to both provide the highest possible
density in the powder mass and melting material components for liquid phase sintering to full
density. Furthermore, the liquid phase components in the powder blend are composed to both
serve as a metallic binder for the green bodies and maintain the possibility to completely dissolve
into the base material, forming a homogenous alloy. A powder blend with stainless steel base
material was composed and tested and taken through the different process steps. While the
formation of green bodies had limited success, to a large extent due to limitations in the process
equipment, the sintering and diffusion behaviour showed promising results, both in respect to
acquired densities, and homogeneity of the material.",,,,,,
"['Arumaikkannu, G.', 'Uma Maheshwaraa, N.', 'Gowri, S.']",2020-02-20T21:01:23Z,2020-02-20T21:01:23Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80053,eng,2005 International Solid Freeform Fabrication Symposium,Open,Genetic Algorithm,A Genetic Algorithm with Design of Experiments Approach to Predict the Optimal Process Parameters for FDM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/73a21b6e-bc8d-4bd1-88f4-bc63cc97d22d/download,,"This paper describes a Genetic Algorithm (GA) with Design of Experiments (DoE)
approach to predict the optimized surface roughness and porosity characteristics of the parts
produced using ABS material on stratasys FDM 2000 machine. The Mathematical Model (MM)
was developed by using Response Surface Methodology (RSM). It is to predict and investigate
the influence of selected process parameters namely slice thickness, road width, liquefier
temperature and air gap and their interactions on the surface roughness and porosity. The
developed MM is the fitness function in GA in order to find out the optimal sets of process
parameters and to predict the corresponding surface quality characteristics. These results have
been validated and the experimental results after GA are found to be in conformance with the
predicted process parameters.",,,,,,
"['Vaughan, D.M.', 'Meyer, L.', 'Masuo, C.', 'Nycz, A.', 'Noakes, M.W.', 'Vaughan, J.', 'Walters, A.', 'Carter, B.', 'Wallace, R.']",2023-04-03T17:34:56Z,2023-04-03T17:34:56Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117725', 'http://dx.doi.org/10.26153/tsw/44604']",eng,2022 International Solid Freeform Fabrication Symposium,Open,DED,Geometric Challenges in Designing Parts for Machining using Wire-fed DED,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c55f0ffd-e5bd-41d6-ba9b-6c5bfdc7066a/download,,"Wire-fed DED using MIG welding systems allows for high deposition rates 
above 30lbs/hr, enabling much larger parts to be printed than would be possible on 
other DED systems. However, a drawback to this high deposition rate is a relatively 
low bead resolution on the printed part. Post-processing using machining is usually 
required on any mating surfaces printed using wire-fed DED. Problems such as 
residual stress in the build plate and printed part, underbuilding, and path 
interpolations can all lead to insufficient material deposition and deviation from the 
desired shape. These areas where the printed part varies from the model can leave 
defects on post-processed surfaces. This paper will cover common geometry issues 
that can arise from wire-fed DED and design changes that can be made to ensure that 
the printed design contains the required material to achieve the finished part.",,,,,,
"['Chang, S.', 'Li, H.', 'Ostrout, N.', 'Jhuria, M.', 'Mottal, S.A.', 'Sigg, F.']",2021-10-21T19:47:57Z,2021-10-21T19:47:57Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89433,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D printing', '3D printers', 'geometric element test targets', 'dimensional variability', 'geometric variability']",Geometric Element Test Targets for Visual Inference of a Printer's Dimension Limitations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c3907aff-2c3f-4377-be3a-bcbfd842f5e2/download,University of Texas at Austin,"As technologies advance in the field of additive manufacturing (AM), it increases the
demand in using test targets to quantitatively appraise the performance of AM processes and parts.
This study presents a unique concept to address the dimensional and geometric viability of threedimensional (3D) printers with test targets that are unique and complementary to those currently
available. We have named these distinct designed artifacts as Geometric Element Test Targets
(GETTs). The concept for the targets is to rely on positioning and spatial frequency of geometric
shapes to induce failures that are indicative of the system’s dimensional limitations. A
distinguishing characteristic is that the dimensional failures can be inspected visually. Systematic
evaluations of the limitations can be further conducted through contact or non-contact
measurements. The initial GETTs include three suites of test targets: line, angular and circular
suites. We will illustrate this concept with samples produced with fused deposition modeling
printers. The potential applications of GETTs include standardization, reference targets, in-line
system control, and more.",,,,,,
"['Gursoz, E. Levent', 'Weiss, Lee E.', 'Prinz, Fritz B.']",2018-04-10T19:25:46Z,2018-04-10T19:25:46Z,1990,Mechanical Engineering,doi:10.15781/T2PC2TS21,http://hdl.handle.net/2152/64250,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['The Engineering Design Research Center', 'Rapid Tool Fabrication System', 'NOODLES']",Geometric Modeling for Rapid Prototyping and Tool Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/264ce5e8-7220-4dd8-996d-01d8c4341a61/download,,"This paper describes the application of a non-manifold geometric modeling
environment, NOODLES, to a Rapid Tool Fabrication System. This
system integrates stereolithography and thermal spray deposition into a
CAD/CAM environment which includes design evaluation tools, robotic
spraying, and computer-aided process planning. The level of integration and
the number of different models in this system requires geometric representations
that can be abstracted at several levels and that can be manipulated
over several dimensions. The models in our framework for design, analysis,
and fabrication share a single comlnon unifying geometric representation
implemented in NOODLES.",,,,,,
"['Knoop, F.', 'Schoeppner, V.']",2021-11-08T23:01:47Z,2021-11-08T23:01:47Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90069', 'http://dx.doi.org/10.26153/tsw/16990']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['geometrical accuracy', 'holes', 'cylinders', 'fused deposition modeling']",Geometrical Accuracy of Holes and Cylinders Manufactured with Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed32b1a4-ecb9-449a-94c1-2bb85057dbe2/download,University of Texas at Austin,"A widely used Additive Manufacturing (AM) technology is Fused Deposition Modeling
(FDM) to create prototypes and end-use parts with close-to-production thermoplastics. For their
use as a final product, it is necessary that additively manufactured parts strictly adhere to the
geometrical requirements of the technical drawing. In this paper, the holes and cylinders of the
cylindrical elements are investigated in terms of achievable geometrical accuracy. For this
purpose, different test specimens that allow a measurement of inner and outer diameters from 3 to
80 mm were designed. All specimens were measured with a coordinate measuring machine
(CMM) to evaluate deviations from the nominal dimension and form deviations. The measuring
method includes a scanning of the surface to record the course of dimensional deviations over the
diameter. Thus, it was possible to visualize how deviations on cylindrical elements manufactured
in FDM occur. In order to counteract these deviations and to improve the dimensional accuracy,
different shrink factors and filling patterns were investigated. Consequently, an improvement of
the dimensional accuracy was achieved.",,,,,,
"['Nettekoven, Alexander', 'Franken, Nicholas', 'Topcu, Ufuk']",2021-11-22T14:54:58Z,2021-11-22T14:54:58Z,9/1/21,Mechanical Engineering,,"['https://hdl.handle.net/2152/90485', 'http://dx.doi.org/10.26153/tsw/17404']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['large-scale 3D printing', 'quantitative analysis', 'printing while flying']",Geometrical Analysis of Simple Contours Deposited by a 3D Printing Hexacopter,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a175969-2bbf-4616-8749-58cdc24e4a5f/download,,"Current limitations in vertical and horizontal mobility for ground robots in 3D printing of medium to large-scale objects have recently led to the development of a 3D printing hexacopter testbed at the University of Texas at Austin. This testbed can fly to a desired location and deposit polylactic acid on flat surfaces. A previous study has shown the feasibility of this approach but has not yet quantified the testbed's printing capabilities. In this paper, we quantify the printing capabilities. We print square contours of different sizes and quantify the printed results based on their geometric dimensions. We also quantify the testbed's trajectory tracking to assess the testbed's positioning accuracy during printing. In quantifying the testbed, we lay the groundwork for using aerial robots in printing applications of medium to large-scale objects, such as concrete printing.",,,,,,
"['Nettekoven, Alexander', 'Franken, Nicholas', 'Topcu, Ufuk']",2021-12-07T18:19:49Z,2021-12-07T18:19:49Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90747', 'http://dx.doi.org/10.26153/tsw/17666']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['3D printing hexacopter', 'testbed', 'geometrical analysis', 'simple contours']",Geometrical Analysis of Simple Contours Deposited by a 3D Printing Hexacopter,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77429b09-8f0b-405e-820d-78b973cc9b40/download,University of Texas at Austin,"Current limitations in vertical and horizontal mobility for ground robots in 3D printing of medium
to large-scale objects have recently led to the development of a 3D printing hexacopter testbed at
the University of Texas at Austin. This testbed can fly to a desired location and deposit polylactic acid on flat surfaces. A previous study has shown the feasibility of this approach but has not
yet quantified the testbed’s printing capabilities. In this paper, we quantify the printing capabilities. We print square contours of different sizes and quantify the printed results based on their
geometric dimensions. We also quantify the testbed’s trajectory tracking to assess the testbed’s
positioning accuracy during printing. In quantifying the testbed, we lay the groundwork for using
aerial robots in printing applications of medium to large-scale objects, such as concrete printing.",,,,,,
"['Lieneke, T.', 'Lammers, S.', 'Zimmer, D.']",2021-12-01T22:56:13Z,2021-12-01T22:56:13Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90646', 'http://dx.doi.org/10.26153/tsw/17565']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'geometrical deviations', 'manufacturing accuracy']",Geometrical Deviations In Additive Manufacturing – Influences On The Manufacturing Accuracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5f750a34-7d39-4ed4-9f4f-26c02e84c3e8/download,University of Texas at Austin,"The advantages of Additive Manufacturing (AM) highlight the capability to become an
inherent part within the product development process. However, process specific challenges harm
its further currency for industrial applications, for instance the high geometrical deviations.
Different process factors influence the manufacturing accuracy and lead to large dimensional, form
and positional deviations. Published research relative to deviations is difficult to compare, because
it is based on several specimens that were manufactured with different processes, materials and
machine settings. This fact emphasizes that reliable tolerance values for AM are hard to define in
standards. Within this investigation, a universally applicable method was developed to examine
geometrical deviations for AM processes. The main aim is the derivation of achievable tolerance
values considering important influencing factors. Furthermore, due to the locally varying surface
roughness of additively manufactured parts several tactile measurements were compared.",,,,,,
"['Gervasi, Vito R.', 'Schneider, Adam', 'Rocholl, Joshua']",2020-02-14T16:16:12Z,2020-02-14T16:16:12Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79990', 'http://dx.doi.org/10.26153/tsw/7015']",eng,2004 International Solid Freeform Fabrication Symposium,Open,hybrid fabrication paths,Geometry and Procedure for Benchmarking SFF and Hybrid Fabrication Process Resolution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82a5b728-48ee-462b-b3bc-575e3b9fcf17/download,,"Since the advent of SFF and RP a number of SFF benchmarking geometries and methodologies
have been developed and employed with some similarities but limited standardization. Minimal
information has been published in regard to a standard method of measuring the resolution limits or
capabilities of SFF and SFF-based hybrid processes. In an effort to benchmark resolution limits of SFF
and Hybrid Fabrication processes, several benchmarking geometries were developed to capture the
resolution capabilities, specifically hole size and rod size range, of multiple hybrid fabrication path steps
and a hybrid path as a whole. These useful geometries are shared with the SFF community and
procedures for their use are described in this paper.",,,,,,
"['Sassaman, D.', 'Ide, M.', 'Beaman, J.', 'Seepersad, C.', 'Kovar, D.']",2021-12-06T21:25:58Z,2021-12-06T21:25:58Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90676', 'http://dx.doi.org/10.26153/tsw/17595']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['geometry limitations', 'geometry', 'indirect selective laser sintering', 'alumina']",Geometry Limitations in Indirect Selective Laser Sintering of Alumina,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5b396a9-26f5-41d1-a9ce-1f6b529e521c/download,University of Texas at Austin,"Ceramics containing open channels with complex geometries can be manufactured by
additive manufacturing (AM) and are of great interest in clean energy technologies. However,
design limitations and guidelines for manufacturing these architectures with AM have not yet
been established. In this work, we compare previously proposed geometry limitations for
polymer selective laser sintering (SLS) to the geometries produced using indirect SLS in
alumina. We focus on a subset of model shapes that are simple to produce and measure. We
show that these rules provide a starting point for the design and manufacture of ceramic
geometries using indirect SLS. However, there are additional considerations for AM of ceramics
by indirect SLS that further limit the geometries that can be produced.",,,,,,
"['Venkataramani, Ravi', 'Das, Suman', 'Beaman, Joseph']",2019-02-18T17:38:51Z,2019-02-18T17:38:51Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73392', 'http://dx.doi.org/10.26153/tsw/544']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Selective laser sintering', 'impermeable']",Geometry Processing for SLS/HIP,Conference paper,https://repositories.lib.utexas.edu//bitstreams/efc3c864-f02e-446f-8a2b-825435becad3/download,,"SLS/HIP is a new net shape manufacturing method that combines
the strengths of direct selective laser sintering and hot isostatic pressing.
Direct selective laser sintering is a rapid manufacturing technique that can
produce high density metal parts of complex geornetry with an integral,
gas iinpenneable skin. These parts can then be directly post-processed by
containerless HIP. Sophisticated processing of the part geometry is
required to facilitate the desired results from SLS/HIP. This paper presents
geometry processing algorithms being developed for in-situ canning of
SLS/HIP components. This research is funded by DARPA IONR contract
NO00 14-95-C-0 139 titled ""Low Cost Metal Processing Using SLS/HIP"".",,,,,,
"['Xing, Xiaodong', 'Yang, Li']",2021-10-21T20:47:30Z,2021-10-21T20:47:30Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89443,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'research and development', 'R&D', 'China']",A Glance at the Recent Additive Manufacturing Research and Development in China,Conference paper,https://repositories.lib.utexas.edu//bitstreams/73852862-5562-4c35-8356-af8dbdf83edd/download,University of Texas at Austin,"This paper reviews some of the recent additive manufacturing research and development works
in China. A considerable amount of AM research activities in China focuses on directed energy
deposition processes, powder bed fusion processes and stereolithography, with much of the
effect dedicated to system and application development. Although many of the recent results
are not readily available from the literatures published in China, from the available information
the areas of focus for research and development could be clearly seen. Despite some
speculations, the AM research in China is vibrate and aggressive, with some areas at least
several years ahead of the other countries.",,,,,,
"['Mitzner, Scott', 'Liu, Stephen', 'Domack, Marcia', 'Hafley, Robert']",2021-10-06T20:30:23Z,2021-10-06T20:30:23Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88435', 'http://dx.doi.org/10.26153/tsw/15372']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Ti-6Al-4V alloy', 'grain refinement', 'electron beam', 'gas-tungsten arc', 'freeform fabrication']",Grain Refinement of Freeform Fabricated Ti-6Al-4V Alloy Using Beam/Arc Modulation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d96ca489-7285-461f-9f07-cc6019d654a3/download,University of Texas at Austin,"Grain refinement can significantly improve the mechanical properties of freeform-fabricated Ti6Al-4V alloy, promoting increased strength and enhanced isotropy compared with coarser
grained material. Large β-grains can lead to a segregated microstructure, in regard to both αphase morphology and α-lath orientation. Beam modulation, which has been used in
conventional fusion welding to promote grain refinement, is explored in this study for use in
additive manufacturing processes including electron beam freeform fabrication (EBF3) and gas-tungsten arc (GTA) deposition to alter solidification behavior and produce a refined
microstructure. The dynamic molten pool size, induced by beam modulation causes rapid heat
flow variance and results in a more competitive grain growth environment, reducing grain size.
Consequently, improved isotropy and strength can be achieved with relatively small adjustments
to deposition parameters.",,,,,,
"['Gupta, Sulabh', 'Rui, Rahul']",2021-10-19T15:23:57Z,2021-10-19T15:23:57Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89298,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'computational pipeline', 'large size 3D models', 'additive manufacturing']",A Graph Grammar Based Approach to 3D Print and Assemble Furniture,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7416d7ee-f51b-4116-bfa4-99437c93631f/download,University of Texas at Austin,"A Plethora of user generated 3D models are available online. With rapid proliferation and
diffusion of additive manufacturing machines in households, it has now become possible to
download these virtual objects and print them out as physical parts. Although printing small size
parts (within print volume of low cost 3D printers) is relatively an easy task, additive fabrication
of large size parts (part volumes greater than print volume of low cost 3D printer) remains a
challenging task for novice 3D printer users. In this paper the authors present a computational
pipeline to 3D print large size 3D models that can be easily downloaded from online websites.
The pipeline essentially enables decomposition of large objects into smaller parts that can be 3D
printed and then assembled. To assemble the printed parts a three-pronged approach is outlined.
First, an interface based on graph grammar rules has been developed to generate assembly
instructions. Second, an interactive segmentation of the desired 3D model is carried out using a
Segmentation Guide Interface (SGI). SGI has been developed to assist a user to carry out
component to sub-component segmentation. Third, we have also developed an interface that aids
a user in printing small size pieces that can be printed in print volume of a commercial 3D printer
(such as Makerbot®) and then assembled to create components that are too large to be printed in
print volumes of low cost 3D printers. We demonstrate the efficacy of developed pipeline by
creating assembly instructions for multiple large sized 3D table models available online.",,,,,,
"['Rosen, David W.', 'Schaefer, Dirk', 'Scrage, Daniel']",2021-10-05T15:41:31Z,2021-10-05T15:41:31Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88394', 'http://dx.doi.org/10.26153/tsw/15333']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Defense Advanced Research Projects Agency', 'MENTOR', 'Georgia Tech', 'high school education program', 'system engineering', 'additive manufacturing']",GT ME TOR: A High School Education Program in Systems Engineering and Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b24454d0-4e1e-4c32-a675-a7f43079216e/download,University of Texas at Austin,"The Defense Advanced Research Projects Agency (DARPA) is sponsoring the MENTOR
program as the outreach part of its Adaptive Vehicle Make suite of programs. Georgia Tech has
been awarded a contract to involve up to 1000 high schools after 4 years in a series of prize
challenges. A web-based collaborative design-manufacturing infrastructure will be developed
that integrates CAD, CAE, design-for-manufacturing, and CAM software tools with a network of
3D printers and other manufacturing resources. In distributed teams, students will design,
fabricate, and construct electro-mechanical systems (e.g., ground vehicle robots) to perform
complex tasks. Many parts they design will be fabricated on 3D printers that are located in high
schools or nearby sites. A project objective is to have students learn about collaborative design,
advanced manufacturing, and new product development practices and to become excited about
pursuing technology-based careers.",,,,,,
"['Luben, Hannah', 'Meisel, Nicholas']",2024-03-27T15:40:42Z,2024-03-27T15:40:42Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124485', 'https://doi.org/10.26153/tsw/51093']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['design for additive manufacturing', 'topology optimization', 'legacy tooling']",GUIDED MANUAL DESIGN FOR ADDITIVE MANUFACTURING OF TOPOLOGICALLY OPTIMIZED LEGACY TOOLING PARTS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ee56e17-4dde-4814-b245-ee1c5d1285b8/download,University of Texas at Austin,"Design for Additive Manufacturing (DfAM) is a unique conceptual way to adapt a part for
Additive Manufacturing (AM). While some of the choices made in DfAM become second nature
to seasoned AM designers, inexperienced designers may not know the nuances involved in what
is still a developing manufacturing technology. Topology Optimization (TO) in particular tends to
create organic shapes that may not be immediately conducive to printing through AM. This paper
proposes a comprehensive workflow tool to guide a designer, regardless of their experience,
through the decision-making process inherent to DfAM. The guide helps the designer manually
edit a legacy tooling design into a topologically optimized part that is readily manufacturable
through AM. Discussion of a relevant case study follows the outline of the design tool to exemplify
its use.",,,,,,
"['Neitzel, F.', 'Kletetzka, I.', 'Schmid, H.-J.']",2024-03-25T22:20:11Z,2024-03-25T22:20:11Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124318', 'https://doi.org/10.26153/tsw/50926']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PBF-LB/P', 'PA12', 'halogen', 'flammability', 'additive manufacturing']",HALOGEN-FREE FLAME-RETARDANT POWDER MATERIALS FOR LASER SINTERING: EVALUATION AND PROCESS STABILITY ANALYSIS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/22c94920-6571-4d07-8c16-f1bb3300a064/download,University of Texas at Austin,"The high flammability of components manufactured by laser-based powder bed fusion of
plastics (PBF-LB/P) using standard polyamide 12 (PA12) powder still severely restricts their use
in industries such as electronics, aviation, and transportation. A key factor for the further
establishment of PBF-LB/P is the expansion of the material portfolio with, for example, refreshable
and halogen-free flame-retardant (FR) powder materials. Accordingly, various halogen-free FRs
are investigated in this work and evaluated with respect to their use in PBF-LB/P. First, their
decomposition behavior and mode of action are examined. Subsequently, the additives are dry
blended with PA12 to investigate properties relevant for PBF-LB/P, such as particle morphology,
thermal behavior, and melt viscosity. Afterwards, test specimens for UL94 vertical
flame-retardancy tests are produced by processing the dry blends on an EOS P3 PBF-LB/P system.
Finally, the process stability of the process-aged powder blends is investigated by again examining
thermal behavior and melt viscosity.",,,,,,
"['Monnier, L.V.', 'Ko, H.']",2023-04-03T17:43:17Z,2023-04-03T17:43:17Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117728', 'http://dx.doi.org/10.26153/tsw/44607']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,HDF5 Hierarchies for Additive Manufacturing digital representations and Enhanced Analytics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b3b83ce5-eed0-4987-80d9-813387db54fc/download,,"Advancement in Additive Manufacturing (AM) technologies and data acquisition techniques have led to 
an increase in AM data generated. However, due to the large volume and the diversity of AM data available it is 
becoming challenging to efficiently store, analyze, and represent AM processes. HDF5 has the potential to allow 
an easy access to big data by offering a hierarchical data catalog. Thus, AM processes could be represented 
through a hierarchy based on the data analytic needs and directly link the corresponding AM data.
This paper investigates the use of data formats to represent big data and AM dataset. Existing AM ontologies 
and models are reviewed in order to effectively encapsulate AM information and incorporate the hierarchy into 
an HDF5 AM wrapper. Three hierarchies are proposed to represent specific perspectives of AM processes: the 
digital twin of AM Product Lifecycle, the AM V model representation, and the material centric characteristics.",,,,,,
"['Duty, Chad E.', 'Fuhrman, Brian T.', 'Jean, Daniel L.', 'Lackey, W. Jack']",2019-09-23T17:03:29Z,2019-09-23T17:03:29Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75973', 'http://dx.doi.org/10.26153/tsw/3072']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Deposition,Heat Transfer Analysis of a Gas-Jet Laser Chemical Vapor Deposition (LCVD) Process 461,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ae8f3c0-4241-4086-9636-ad7bfde89528/download,,This paper describes the development of a computer model used to characterize the heat transfer properties of a gas-jet LCVD process. A commercial software package was used to combine heat transfer finite element analysis with the capabilities of computational fluid dynamic software (CFDS). Such a model is able to account for both conduction and forced convection modes of heat transfer. The maximum substrate temperature was studied as a function of laser power and gas-jet velocity.,,,,,,
"['Michaelis, Matthew', 'Zhu, Jun', 'Orme, Melissa']",2019-10-24T17:49:13Z,2019-10-24T17:49:13Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77407', 'http://dx.doi.org/10.26153/tsw/4496']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Manipulation,Heat Transfer Manipulation for Precision Droplet Manufacturing: Simulation and Experiment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/234d56d7-e594-4612-92b8-d8cf185b53f9/download,,"The solid free-form fabrication (SFF) of arbitrary metallic components is accomplished with
controlled deposition of nano-liter molten droplets generated by capillary stream break-up and
deposited at rates on the order of 10,000 drops/second. By varying the droplet arrival
temperature, deposition rate, and substrate temperature in both the simulation and experiment,
we seek to obtain a thorough understanding of the heat transfer phenomena that governs the SFF
component quality. Of specific interest is the removal of inter-splat boundaries in order to
achieve a high quality component, characterized by a uniform and fine microstructure, by having
newly arriving drops remelt a thin layer of the previously deposited and solidified material. A
numerical model, which simulates the heat transfer manipulation, is used to understand and
guide the process development.","We gratefully acknowledge the generous funding from the National Science Foundation, grant
number DMI-0070053, ""High-Speed Droplet-Based Manufacturing of High-Precision Structural
Components and Photonic BandGap Materials.""",,,,,
"['Saiz, Natalia', 'Pegues, Jonathan', 'Whetten, Shaun', 'Kustas, Andrew', 'Chilson, Tyler']",2023-01-27T17:48:50Z,2023-01-27T17:48:50Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117346', 'http://dx.doi.org/10.26153/tsw/44227']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Ti-6Al-4V,Heat Treatment Effects on Mechanical Properties of Wire Arc Additive Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6739a44-85b0-4e5f-91cc-b681247cddb7/download,,"Directed energy deposition (DED) is an attractive additive manufacturing (AM) process 
for large structural components. The rapid solidification and layer-by-layer process associated 
with DED results in non-ideal microstructures, such as large grains with strong crystallographic 
textures, resulting in severe anisotropy and low ductility. Despite these challenges, DED has 
been identified as a potential solution for the manufacturing of near net shape Ti-6Al-4V 
preforms. In this work, we explore several heat treatment processes, and their effects on tensile 
properties of wire arc additively manufactured (WAAM) Ti-6Al-4V. A high throughput tensile 
testing procedure was utilized to generate statistically relevant data sets related to each specific 
heat treatment and sample orientation. Results are discussed in the context of microstructural 
evolution and the resulting fracture behavior for each condition as compared to conventionally 
processed Ti-6Al-4V.",,,,,,
"['Ma, Xulong', 'Lin, Feng', 'Zhang, Lei']",2021-10-19T18:29:40Z,2021-10-19T18:29:40Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89319,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['binder jetting additive manufacturing', 'building error', 'binder infiltration', 'powder bed', 'heterogeneous compensation']",The Heterogeneous Compensation for the Infiltrative Error of the Binder Jetting Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/54b04e79-3b68-4ee3-9a6a-0f707348e53b/download,University of Texas at Austin,"In binder jetting additive manufacturing, such as Three Dimensional Printing (3DP) and Patternless
Casting Manufacturing (PCM, a process similar as ExOne and VoxelJet), the building error is mainly
caused by the infiltration by the binder in the powder bed, and appear heterogeneous magnitude
along different orientations because of the different infiltrating depth of the printed binder between
the building direction and the binder printing direction. Current methods to compensating these error
are mostly based on the contour equidistant offset and the model shrinkage, which couldn’t deal
with the heterogeneous infiltrative error. In this paper, we will propose a novel compensation
method, in which the STL model will be counteracted heterogeneously in different directions to
compensate the heterogeneous infiltrative distances of the binder in the powder. By this method, a
sphere STL model will be transferred into an ellipsoid with variant axis length along different X/Y/Z
directions. The method could greatly improve the dimensional accuracy of a series of additive
manufacturing techniques which are based on the binder jetting onto powder bed.",,,,,,
"['Biswas, Arpan', 'Shapiro, Vadim', 'Tsukanov, Igor']",2019-10-23T15:25:12Z,2019-10-23T15:25:12Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76761', 'http://dx.doi.org/10.26153/tsw/3850']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Material Modeling,Heterogeneous Material Modeling with Distance Fields,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd2f6678-2e3d-4da3-a1f7-b7932d3d5beb/download,,"We propose a universal approach to the outstanding problem of computer modeling of continuously varying distributions of material properties satisfying prescribed material quantities
and rates on a finite collection of geometric features. The central notion is a parameterization
of the shape’s interior by distances from the material features - either exactly or approximately;
this parameterization supports specification, interpolation, and optimization of desired material distributions in a systematic and controlled fashion. We demonstrate how the approach can
be implemented within the existing framework of solid modeling and its numerous advantages,
including:
• precise and intuitive control using explicit, analytic, differential, and integral constraints
specified on the original (not discretized) geometric model;
• applicability to material features of arbitrary dimension, shape, and topology; and
• guaranteed smoothness and analytic properties for superior performance, analysis and
optimization.
Last, but not least, the proposed approach subsumes and generalizes a number of other proposals for heterogeneous material modeling for FGM, heterogeneous solid modeling, and solid
free-form fabrication.",,,,,,
"['Morvan, Stephane M.', 'Fadel, Georges M.']",2019-03-12T16:30:28Z,2019-03-12T16:30:28Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73597', 'http://dx.doi.org/10.26153/tsw/739']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Solid freeform fabrication']",Heterogeneous Solids: Possible Representation Schemes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3366785d-cdf9-415d-bac9-fc306adc6bf9/download,,"Solid freeform fabrication processes allow parts to be built with accuracy and mechanical
integrity, permittingthem to be used in tooling or fOrlnandfit applications. There is already a need
form~lti ..color Parts.for surgical applications, which will eventually lead to. multi-material RP
.machines.WhetherJor on the spot color deposition or for functionally tailored multiple materials
parts,.RPmachines with such capabilities are becoming available. They will eventually lead to the
trtiepromise of Solid Freeform Fabrication: a system that can build a functional mechanism
without assembly, and from multiple materials. This paper is aimed at understanding the new
challenges raised from representing solids whose material distribution is changing gradually from
one material to another (HC), and those made of a collection .of discrete materials (HD). Several
representation schemes are reviewed and critiqued. Techniques borrowed from medical imaging
and geoscience modeling are used to better understand the modeling of heterogeneous and gradient
solids, from a geometric standpoint.",,,,,,
"['Roh, Byeong-Min', 'Yang, Hui', 'Simpson, Timothy W.', 'Jones, Albert T.', 'Witherell, Paul']",2023-01-27T13:53:05Z,2023-01-27T13:53:05Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117332', 'http://dx.doi.org/10.26153/tsw/44213']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,A Hierarchical V-Network Framework for Part Qualification in Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be0968d4-c962-4b6e-a14f-59cb9b26b6fb/download,,"Advances in metal additive manufacturing (AM) technologies have enabled greater design freedoms than 
subtractive manufacturing has afforded. The design freedoms and flexibilities offered by a metal AM 
system, however, dramatically increase process uncertainties that may also increase part-quality 
variabilities. Any metal AM part must be tested, validated, and verified to meet quality, safety, and 
performance requirements. Common qualification methodologies rely on destructive testing, which is 
neither cost-effective nor efficient. Much research, which has been conducted on sensing-based, part 
qualification in AM systems, attempts to maximize the reduction of destructive testing by closely 
monitoring the fabrication process in real-time. So much “big data” is generated by this increased use of 
sensors and available measurement sources. However, the use of the data is still hindered by 1) scale & size 
and 2) uniformity. We propose a hierarchical, V-network framework of quality assurance with the 
corresponding translation from ex-situ to in-situ part qualifications. This framework offers an innovative, 
Cyber-Physical System (CPS) that accurately ties models, processes, and measurements together to 
interpret the sensor data. The framework also supports and guides translation from ex-situ to in-situ quality 
measurements, thereby providing a systematic structure and focusing on interrelationships between key 
observations that influence AM part quality. Ultimately the sensor data can support the detection of process 
anomalies, thus providing a more streamlined and more efficient qualification process than is otherwise 
possible.",,,,,,
"['Rosen, David W.', 'Jeong, Namin', 'Wang, Yan']",2021-09-30T19:29:27Z,2021-09-30T19:29:27Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88285', 'http://dx.doi.org/10.26153/tsw/15226']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'CAD model', 'model microstructure', 'mechanical properties', 'hierarchical modeling method', 'porosity', 'laser irradiance', 'image processing', 'computational materials design']","A Hierarchical, Heterogeneous Material CAD Model with Application to Laser Sintering",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b358115b-d080-43a8-a028-dc08747c644c/download,University of Texas at Austin,"Variations in laser irradiance and local temperatures in laser sintering cause variations in
porosity and material microstructure, which can affect mechanical properties of a part. From the
design perspective, it is important to model microstructures, mechanical properties, and their
relationships so that parts can be analyzed and designed taking into account their as-manufactured condition. In this paper, we propose the modeling of part geometry and
microstructure by using a new hierarchical modeling method. A surfacelet transform is
introduced to model microstructure. The application of image processing methods enables
multi-resolution representations of microstructure. Combined with methods from computational
materials design, low resolution microstructure representations can be used to compute effective
mechanical properties. The models and methods are demonstrated on two examples, a simple
fiber-reinforced composite and a laser sintered nylon-12 material.",,,,,,
"['Mumtaz, K. A.', 'Hopkinson, N.', 'Erasenthiran, P.']",2020-02-28T15:34:15Z,2020-02-28T15:34:15Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80111', 'http://dx.doi.org/10.26153/tsw/7132']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,High Density Selective Laser Melting of Waspaloy®,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f561027-8007-4886-970d-5975f7585cba/download,,"In this work, high density Waspaloy® specimens were produced using specially assembled
laboratory equipment by Selective Laser Melting (SLM). SLM of Waspaloy® powder was
performed using a high power pulsed Nd:YAG laser. The laser parameters pulse energy (J), pulse
width (ms), repetition rate (Hz) and scan speed (mm/min) were varied. Process parameter
optimization was achieved using factorial analysis to investigate the relationship between specific
processing parameters and the formation of Waspaloy® specimens. The optimized processing
parameters produced Waspaloy® specimens that were 99.3 % dense. The resultant laser melted
specimen’s height, width and contact angles were measured. Specimens were also observed for
the occurrence of porosity.",,,,,,
"['Kong, Chang-Jing', 'Tuck, Christopher J.', 'Ashcroft, Ian A.', 'Wildman, Ricky D.', 'Hague, Richard']",2021-10-05T13:42:56Z,2021-10-05T13:42:56Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88370', 'http://dx.doi.org/10.26153/tsw/15309']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'Ti6Al4V', 'density', 'material properties']",High Density Ti6Al4V via Slim Processing: Microstructure and Mechanical Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ca44fe45-e625-4e0c-bba1-db5bc94b758c/download,University of Texas at Austin,"This paper investigates a density improvement method for Ti6Al4V alloy processed by the selective
laser melting method. A modified inert gas inlet baffle has been employed to develop improved mechanical
properties for these materials. Comparisons of the top surface and cross-section porosities of solid blocks
processed by the original and modified gas inlet baffles indicate that the modified baffle greatly increases the
properties of the processing blocks. Results showed that the porosity of the Ti6Al4V alloy was lower than 0.1%
by area. The microstructure of the SLM Ti6Al4V alloy exhibited martensitic α' phase. The UTS tensile strength
was 920-960MPa and the elongation at the fracture was 3-5%. The fracture surfaces of the tensile samples
demonstrated a mixture of ductile and brittle fracture.",,,,,,
"['Karthik, N.V.', 'Gu, Hengfeng', 'Pal, Deepankar', 'Starr, Thomas', 'Stucker, Brent']",2021-10-07T18:25:34Z,2021-10-07T18:25:34Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88500', 'http://dx.doi.org/10.26153/tsw/15434']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic consolidation', 'ultrasonic testing', 'additive manufacturing', 'non-destructive analysis', 'non-destructive testing']",High Frequency Ultrasonic Non Destructive Evaluation of Additively Manufactured Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90e0ef0b-6818-4931-a0be-35d711b1128e/download,University of Texas at Austin,"Ultrasonic testing of additively manufactured components is useful for non-destructive
defect analysis such as porosity, void and delamination detection as well as for analysis of
material properties such as density, material strength and Young’s modulus. A high
frequency ultrasonic system has been set up on a Fabrisonics Ultrasonic Additive
Manufacturing (Ultrasonic Consolidation) machine to measure the material properties
after each layer. The same system is also used to perform offline tests of parts fabricated by
SLM. Traditional material analysis carried out using SEM and optical microscopy is used to
validate and demonstrate the effectiveness of the non-destructive testing equipment.",,,,,,
"['Grau, Jason', 'Moon, Jooho', 'Uhland, Scott', 'Cima, Michael', 'Sachs, Emanuel']",2018-12-05T17:43:19Z,2018-12-05T17:43:19Z,1997,Mechanical Engineering,doi:10.15781/T2DV1D80B,http://hdl.handle.net/2152/71403,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['3DP', 'silicon nitride']",High green density ceramic components fabricated by the slurry-based 3DP process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f7b249f-e001-4012-9a20-a7cb0f2d281b/download,,"The 3DP process has been modified to directly fabricate high green density parts using
submicron powder. The slurry-based 3DP process deposits the powder bed by spraying a
dispersed slurry of the component material onto a piston. Alumina, silicon nitride, and
lead zirconate titanate components with green densities as high as 67% have been
fabricated by the slurry-based 3DP process. Solution phase binder systems have proven
to be successful for the new process. Substantially improved surface finish over the
conventional dry powder-based 3DP process has been demonstrated. Layer heights less
than 50 Jlm can be prepared with this process. Thus, the stepped surface topography
commonly observed in solid free form parts is substantially reduced.",,,,,,
"['Schleifenbaum, J.H.', 'Theis, J.', 'Meiners, W.', 'Wissenbach, K.', 'Diatlov, A.', 'Bültmann, J.', 'Voswinckel, H.']",2021-09-30T13:56:23Z,2021-09-30T13:56:23Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88252', 'http://dx.doi.org/10.26153/tsw/15193']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['High Power Selective Laser Melting', 'series production', 'additive metal manufacturing', 'kW laser', 'optical multi-beam system']",High Power Selective Laser Melting (HP SLM) - Upscaling the Productivity of Additive Metal Manufacturing towards Factor 10,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a310d698-ab66-49b1-b0b7-c22b11c446d6/download,University of Texas at Austin,"World market competition boosts trends like mass customization and open innovation which result in a demand for highly individualized products at costs matching of beating those of mass production. One of the manufacturing technologies with greatest potential to meet those demands is Selective Laser Melting (SLM) due to its almost infinite freedom of design and the provision of series-identical mechanical properties without the need for part-specific tooling, downstream sintering process, etc. However, the state-of-the-art productivity is not yet suited for series production. Hence, a new machine prototype including a kW laser and an optical multi-beam system is developed and set up. Experimental findings and first applications demonstrate the capability of the new system.",,,,,,
"['Maxwell, James', 'Krishnan, Ramnath', 'Haridas, Suresh']",2018-12-06T20:57:18Z,2018-12-06T20:57:18Z,1997,Mechanical Engineering,doi:10.15781/T2FN11C49,http://hdl.handle.net/2152/71427,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'HPCE-LCVD']","High Pressure, Convectively-Enhanced Laser Chemical Vapor Deposition of Titanium",Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb856ada-98a4-4ab7-a151-418985466c9e/download,,"Laser chemical vapor deposition is a freeform technique that can generate
three-dimensional structures from organometallic or metal halide precursors. To
obtain enhanced growth rates, a novel high pressure reactor has been constructed
where impinging jets of volatile fluids are heatedand pyrolyzed to create parts.
Argon Ion and Nd:YAG lasers have been used to selectively generate three-dimensional
titanium shapes from titanium tetrachloride, titanium tetrabromide, and titanium
tetraiodide, at pressures up to 3.0 atmospheres. Emission lines characteristic
ofthe reaction rate have been identified which will allow feedback control ofthe
reaction rate. The process is being optimized to obtain high deposition rates, energy
efficiency, and desirable material morphologies. A feedback control system is
required to generate 3-D structures with dimensional accuracy and predictable
deposition rates.",,,,,,
"['Da, Cheng', 'Qi, Gang', 'Rangarajan, Sriram', 'Wu, Suxing', 'Langrana, Noshir A.', 'Safari, Ahmad', 'Danforth, Stephen C.']",2018-12-05T20:08:18Z,2018-12-05T20:08:18Z,1997,Mechanical Engineering,doi:10.15781/T2NC5SZ73,http://hdl.handle.net/2152/71409,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD']","High Quality, Fully Dense Ceramic Components Manufactured Using Fused Deposition of Ceramics (FDC)",Conference paper,https://repositories.lib.utexas.edu//bitstreams/42e4d685-2642-4934-96b5-e570a4d7a934/download,,"Solid Freeform Fabrication (SFF) is a technology that produces physical solid components or
parts from computer design models. This technology has the potential of reducing functional
ceramic product development cycle time in terms of reducing design iteration and production
time, minimizing extra post processing, and therefore reducing cost. A commercially available
Fused Deposition Modeling (FDM™) 3D Modeler was altered for use with ceramics. This
newly developed method referred to as Fused Deposition of Ceramics (FDC) is capable of
fabricating complex shape, functional ceramic components.
We have investigated issues related to hardware, software, feed material, and build strategy which
are required to achieve high quality, fully dense green ceramic parts. In this paper, we report
recent improvements made in the FDC process, including hardware modifications, software
improvements, feed material standardization, as well as build strategy/condition control. We also
report the current FDC status for making complex functional parts. Our goal is to optimize the
FDC condition to ensure its robustness for producing defect free green ceramic parts consistently
and without interruption.",,,,,,
"['Streek, A.', 'Regenfuss, P.', 'Exner, H.']",2021-10-12T22:39:47Z,2021-10-12T22:39:47Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88759', 'http://dx.doi.org/10.26153/tsw/15693']",ara,2014 International Solid Freeform Fabrication Symposium,Open,"['laser micro sintering', 'metals', 'additive manufacturing', 'powder', 'density']",High Resolution Laser Melting with Brilliant Radiation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e307496-ec5b-40e4-95c6-3b4750e0a4f2/download,University of Texas at Austin,"Since the discovery of selective laser sintering/melting, numerous modifications have
been made to upgrade or customize this technology for industrial purposes. Laser micro sintering
(LMS) is one of those modifications: Powders with particles in the range of a few micrometers
are used to obtain products with highly resolved structures. Pulses of a q-switched laser had been
considered necessary in order to generate sinter layers from these µm-scaled metal powders.
However, despite the high resolution, the process repeatability of LMS and the material property
of the products have never been completely satisfactory. Recent technological and theoretical
progress and the application of brilliant continuous laser radiation have now allowed for efficient
laser melting of µm-scaled metal powders. Thereby, it is remarkable that thin sinter layers are
generated with a very high laser power. The resulting product resolution is comparable to the one
achieved by the LMS regime with q-switched pulses. From the experimental results the
performance and potential of this high resolution laser melting regime is demonstrated and the
limits of the applicable parameters are deduced.",,,,,,
"['Abdi, M.', 'Ashcroft, I.', 'Wildman, R.']",2021-10-18T22:41:10Z,2021-10-18T22:41:10Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89278,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'Finite Element Method', 'Extended Finite Element Method', 'Iso-XFEM']",High Resolution Topology Design with Iso-XFEM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/585d5ee9-4e26-4c00-8589-99c4a64de180/download,University of Texas at Austin,"Topology optimization, as a challenging aspect of structural optimization, has gained
interest in recent years as a method of designing structures to take advantage of the design
freedoms of advanced manufacturing techniques such as Additive Manufacturing (AM). The
majority of topology optimization algorithms are integrated with the Finite Element Method
(FEM) to enable the analysis of structures with complex geometry during the optimization
process. However, due to the finite element-based nature of the subsequent topology optimized
solutions, the design boundaries are dependent on the finite element mesh used and tend not to
have the desired smoothness for direct fabrication. The topology optimized solutions may,
therefore, need smoothing, reanalysing and shape optimization before they become
manufacturable. In this study, an Extended Finite Element Method (X-FEM) is employed and
integrated with an evolutionary structural optimization algorithm, aiming to avoid/decrease the
post-processing required from topology optimization design to manufacture. Rather than using
finite elements for boundary representation, an isoline/isosurface approach is used to capture the
design boundary during the optimization process. The comparison of the X-FEM-based solutions
with the FE-based ones for the topology optimization of test cases representing real industrial
components indicates significant improvements in the solutions’ boundary representation as well
as their structural performance.",,,,,,
"['Hopkinson, Neil', 'Erasenthiran, Poonjolai']",2020-02-13T20:07:19Z,2020-02-13T20:07:19Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79973', 'http://dx.doi.org/10.26153/tsw/6998']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,High Speed Sintering - Early Research into a New Rapid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4fc6b7e-9cbc-4f06-a72f-e1e5d1dc2053/download,,"Rapid Manufacturing (the production of end use products by layer manufacturing techniques) has grown significantly in recent years and has started to revolutionise some areas of manufacturing. Among the main drawbacks for commercially available
techniques are machine cost and build speed. This paper describes some initial research into a new process called High Speed Sintering. The High Speed Sintering process (UK patent No. 0317387.9) involves the sintering of 2D profiles of layers of powder without the need for a laser. Experiments performed on a simple lab apparatus have shown how the addition of carbon black to
standard nylon powder can increase the rate of sintering such that an entire layer may be sintered in 5 seconds using an infra-red lamp. The effects of composition of carbon black on material properties are shown and may be traded off against build
speed. Thermal control of the process is vital and the effects of altering the position and power used with an infra-red lamp are presented. Eliminating a laser reduces machine cost and build time, combining these factors will make the High Speed Sintering process suitable for high volume manufacture. Cost predictions show that the process will be viable for the manufacture of standard products in volumes over 100,000.",,,,,,
"['Thomas, Helen R.', 'Hopkinson, Neil', 'Erasenthiran, Poonjolai']",2020-03-05T19:54:12Z,2020-03-05T19:54:12Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80151', 'http://dx.doi.org/10.26153/tsw/7172']",eng,2006 International Solid Freeform Fabrication Symposium,Open,High Speed Sintering,High Speed Sintering – Continuing Research into a New Rapid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/340d7027-d2ee-41f1-9f1b-7c75f35a2241/download,,"High Speed Sintering (HSS) is an emerging layer manufacturing technique aiming to break
into the lucrative field of Rapid Manufacturing (RM). The process is likened to Selective
Laser Sintering (SLS), however, instead of a laser dictating the sintered cross sectional area of
each layer, the desired area is first printed using a Radiation Absorbing Material (RAM) and
then sintered using an inexpensive infrared lamp. This paper begins by describing the
sintering process in more detail and then outlining the overall manufacturing cycle. It then
continues by describing the experiments performed to investigate the current problem
concerning the hardness of excess powder within the powder bed. This problem arose due to
the continual exposure of the whole bed to infrared radiation from the lamp. The experiments
showed that as the power of the IR lamp increased, the hardness of the bed also increased.
Furthermore, at higher IR power levels it was found the excess powder produced a solid tile
which could only be broken down by a glass bead blaster.",,,,,,
"['Yamazawa, Kenji', 'Niino, Toshiki', 'Hayano, Seiji', 'Nakagawa, Takeo']",2018-11-29T21:06:38Z,2018-11-29T21:06:38Z,1997,Mechanical Engineering,doi:10.15781/T2M03ZH3J,http://hdl.handle.net/2152/70345,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['laser optical', 'overflow method']",High Speed UV Laser Beam Scanning by Polygon Mirror,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed73fa36-8d5d-4c52-97b4-b38ccd2951ba/download,,"Since the stereolithograpy system appeared on the market, various rapid prototyping
machines based on the layer laminated manufacturing process have emerged one after the other,
the range of applications of which is classified according to their features. Of these,
stereolithogrraphy methods which make use ofphotocurable resin as material and laser beam as
processing tools are gradually being established. They are currently the most widespread with a
rich variety of models available. The scanning device used in stereolithography serves as the
key technology for this method but consists basically of only the galvanometer mirror known
for outstanding high speed ability and the XY plotter known for outstanding scanning position
accuracy1),2). Lately, many models are seen to use the galvanometer mirror due to improved
accuracy, but still this scanning device is used only when the fabrication size allows, etc. From
such reasons, the authors have developed a laser stereolithograpy system capable of high speed
high accuracy position scanning by the high speed raster scanning method using a polygon
mirror as the scanning device3). The polygon mirror, which has a higher scanning speed than the
galvanometer mirror, is moved along the NC servo shaft and the raster scanning spacing is made
considerably smaller than the laser beam spot diameter.
This paper describes this system and the results offabrication experiments with this system.",,,,,,
"['Vanmunster, L.', 'Dejans, A.', 'Van Hooreweder, B.', 'Vrancken, B.']",2024-03-26T20:51:52Z,2024-03-26T20:51:52Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124407', 'https://doi.org/10.26153/tsw/51015']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['high speed video', 'beam shaping', 'overhang', 'laser powder bed fusion']",HIGH SPEED VIDEO IMAGING OF OVERHANG SURFACES IN BEAM SHAPED LASER POWDER BED FUSION OF 316L STAINLESS STEEL,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e640f5f-4a59-4e27-b9aa-43845decc525/download,University of Texas at Austin,"Beam shaping has seen rising interest in the AM industry and research field because of the increased level of
control over the spatial distribution of the thermal input during Laser Powder Bed Fusion, allowing for faster
build rates. This report investigates if the more uniform heat input offers benefits to the scanning of unsupported
overhanging structures. In-situ high speed video imaging is combined with post process surface characterization
to derive a relation between the scan parameters and quality of the overhang surface. The best results were
achieved at low energy densities, but no clear advantage of top-hat shaped laser spots over the standard Gaussian
beams is observed.",,,,,,
"['Fish, S.', 'Kubiak, S.', 'Wroe, W.', 'Booth, J.', 'Bryant, A.', 'Beaman, J.']",2021-10-19T18:19:24Z,2021-10-19T18:19:24Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89316,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['High Temperature Polymers', 'Selective Laser Sintering', 'testbed', 'process control']",A High Temperature Polymer Selective Laser Sintering Testbed for Controls Research,Conference paper,https://repositories.lib.utexas.edu//bitstreams/30c54b33-8f24-4001-8d44-eeb88353e36d/download,University of Texas at Austin,"High Temperature Polymers under development over the last decade show great promise for
Additive Manufacturing (AM) applications in aviation, medicine, and other fields based on their
high strength and high temperature qualities. Selective Laser Sintering (SLS) of these materials,
derived generally from the Poly Ether Ketone Ketone class of polymers is still somewhat
immature however, and certifiably repeatable SLS parts with certifiable mechanical properties
remain elusive. One barrier to this is the limited number and high cost of SLS machines capable
of operating at the high ~300-350C temperatures needed to build with low internal thermal stress
and tight process controls. Another barrier is the lack the instrumentation in the few machines
available, to develop critical feedback control and associated flexibility in the thermal
management of the material from feedstock to cooled part/part-cake. This paper describes the
development and initial testing of a new laboratory SLS machine with the flexibility required in
deriving optimal process control for polymer SLS including these high temperature polymer
powders. With such a system validated for SLS operation, we will embark on multiple control
development approaches to improve part/material property performance.",,,,,,
"['España, Félix A.', 'Balla, Vamsi Krishna', 'Bose, Susmita', 'Bandyopadhyay, Amit']",2021-09-29T20:16:43Z,2021-09-29T20:16:43Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88211', 'http://dx.doi.org/10.26153/tsw/15152']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['surface modification', 'thermal conductivity', 'metal coating', 'Laser Engineered Net Shaping', 'LENS']",High Therma,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fad5a991-77dd-4e8d-8972-3f4ade4a0814/download,University of Texas at Austin,"Surface modification has been used to improve wear resistance, corrosion resistance and thermal
barrier properties of metals. However, no significant attempts have been made to improve
thermal conductivity by surface modification. In this work, we have examined the feasibility of
enhancing thermal conductivity (TC) of stainless steel by depositing brass using Laser
Engineered Net Shaping (LENS). The coating increased the TC of the substrate by 65% at 100
C°. Significantly low thermal contact resistance was observed between the coating and the
substrate due to minimal dilution and defect free sound interface. Our results indicate that laser
processing can be used on low coefficient of thermal expansion metal matrix composites to
create feature based coatings to enhance their heat transfer capability.",,,High Thermal Conductivity Coatings via LENS™ for Thermal Management Applications,,,
"['Ledesma-Fernandez, J.', 'Tuck, C.', 'Hague, R.']",2021-10-19T17:43:53Z,2021-10-19T17:43:53Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89307,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['high viscosity fluid', 'drop-on-demand', 'ink-jet printing', 'conductive pastes', 'dielectric pastes', 'printed electronics']",High Viscosity Jetting of Conductive and Dielectric Pastes for Printed Electronics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9d04a680-db98-4fdf-86e9-4655f8346261/download,University of Texas at Austin,"Ink-jet printing of multiple materials in 3 dimensions is a promising alternative to
traditional patterning methods due to its flexibility, scalability and accuracy. However, the
printability of the inks is strongly restricted by material properties such as surface tension and
viscosity. Dispensing high viscosity fluids on a drop-on-demand approach is a potential solution
that can facilitate the incorporation of new materials to the jetting catalogue. Consequently, in
this study 2 micro-dispensing valves are used in combination with a mechanical stage to deposit
conductive and dielectric pastes with viscosities of 15.3 ± 0.2 and 0.638 ± 0.005 Pa·s (at 25°C
and 10 s-1 shear rate) respectively. Crucial printing parameters such as pressure, temperature,
pulse shape and drop spacing are studied in order to optimise the process. Additionally, post-printing characteristics such as contact angle of different materials and cured layer profiles are
also measured and taken into account during the designing of the 3D patterns to minimise the
negative effects of the thickness miss-match of different materials. Finally, the manufacturing
capability of the set-up is demonstrated by the fabrication of a functional device using a
combination of “pick-and-place” components and high viscosity jetting.",,,,,,
"['Yang, H.', 'He, Y.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Dickens, P.', 'Hague, R.']",2021-10-11T20:57:44Z,2021-10-11T20:57:44Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88642', 'http://dx.doi.org/10.26153/tsw/15576']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['3D inkjet printing', 'high viscosity ink', 'process parameters', 'temperature', 'pressure', 'jetting performance', 'jetting']",High Viscosity Jetting System for 3D Reactive Inkjet Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50497175-7e2e-48db-84bc-a4eb3b10892c/download,University of Texas at Austin,"High viscosity ink is a potential solution for the improvement of current 3D ink jetting
technology. In this study, experiments are carried out to study a series of inks with differing
viscosities jetted with PicoDot™ jet valves under different process parameters of temperature
and pressure. Results show that a wide range of ink materials from low viscosity (water like
materials) to very high viscosity (thixotropic materials) can be jetted with the piezoelectric
actuated jet valves without the need of solvents and surfactants. The jetting volume can be
controlled under certain conditions between 2nl and 15nl. The jetting performances for low,
medium and high viscosity inks have been recorded by high-speed video photography.",,,,,,
"['Fischer, S.', 'Pfister, A.', 'Galitz, V.', 'Lyons, B.', 'Robinson, C.', 'Rupel, K.', 'Booth, R.', 'Kubiak, S.']",2021-10-27T22:33:23Z,2021-10-27T22:33:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89634,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['PEKK composites', 'carbon fiber', 'laser sintering', 'aerospace']",A High-Performance Material for Aerospace Applications: Development of Carbon Fiber Filled PEKK for Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ab093a90-e99a-4b83-903e-542e4cd58b63/download,University of Texas at Austin,"In a time where rapid prototyping successively transforms to additive manufacturing (AM), nylon 11
and 12 and their composite powders, which have evolved to be the most commonly used materials in laser
sintering (LS) due to their easy processability, cannot fulfil all challenging requirements of industrial
applications any more. Especially in the aerospace industry, there is a high demand for stiff and lightweight
parts for interiors, which currently are fabricated from glass fiber reinforced phenolic and epoxy resins by a
lamination process. Due to the strong diversity of the parts, this traditional manufacturing is quite labor-intensive and expensive, which makes it very attractive to manufacture these parts with additive manufacturing,
especially laser sintering. Additional part design requirements, such as greater chemical and UV resistance, an
elevated softening temperature, higher mechanical strength and better performance in flammability and heat
release tests generate opportunities for the use of high performance AM polymers. Promising candidates that
have the potential of satisfying these demands can be found among the different Polyaryletherketone
thermoplastics.
In this work we present the development of a carbon fiber filled PEKK composite material for laser sintering,
optimized especially for the production of interiors, such as air ducts for cabin ventilation in aerospace
application.
Based on process tests, powder characterization and test builds, the material and its manufacturing procedure
were optimized towards isotropic properties and refreshability. Simulations of building cycles helped to
understand the extent of powder ageing, which is directly connected to the ability to recycle the material.
Furthermore the laser sintering hardware of an EOSINT P800 and the building processes were adapted to ensure
a stable building process and fulfill the requirements of parts on mechanical properties in x, y and z directions,
dimensional stability and surface quality.",,,,,,
"['Elsab, A.', 'Wegner, Jan', 'Schonrath, Hanna', 'Horstjann, Niklas', 'Kleszczynski, S.']",2024-03-26T20:54:38Z,2024-03-26T20:54:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124408', 'https://doi.org/10.26153/tsw/51016']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'PBF-LB/M', 'process monitoring', 'high resolution', 'balling effect']",HIGH-PRECISION MEASUREMENT OF MELT POOL PROPERTIES DURING LASER-BASED POWDER BED FUSION OF METALS BY HIGH-SPEED IMAGING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/06d98b9c-0e4c-4de4-b982-0c9446926fe7/download,University of Texas at Austin,"Laser-based powder bed fusion of metals is used to produce complex and high-performance
components for different industrial applications. Due to the high complexity of the underlying
physical mechanisms during the process, its control is still challenging. To avoid the formation of
defects, which affect mechanical properties, a huge amount of specific know-how is crucial.
Especially for regulated industries, such as medical or aerospace, this is a limiting factor for the
widespread usage. In this work, high-speed imaging in combination with a high-magnification
optic is used to gain deeper insight into the property-determining mechanisms and boundary
conditions during the process. Thereby, the intensity distribution from the melt pool radiation is
measured and analyzed with an imaging script to determine width, length, and cooling rate with a
resolution of 1.44 µm/pixel. The potential of this data for predicting resulting scan track properties
is demonstrated. It can be shown that an automatic width measurement deviates from the manually
measured value by only 1.2% and the length measurement by 1.4%. It is also possible to detect
anomalies in the process, such as balling effects.",,,,,,
"['Sammons, Patrick M.', 'Barton, Kira']",2021-11-04T20:30:02Z,2021-11-04T20:30:02Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90021', 'http://dx.doi.org/10.26153/16942']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['molten polycaprolactone', 'PCL', 'electrohydrodynamic jet printing', 'e-jet printing']",High-Resolution Electrohydrodynamic Jet Printing of Molten Polycaprolactone,Conference paper,https://repositories.lib.utexas.edu//bitstreams/124233b6-2335-438c-94de-acae6abf4bbd/download,University of Texas at Austin,"Polycaprolactone (PCL) is a biocompatible and biodegradable polymer that is commonly
used in drug delivery systems, medical structures, and tissue engineering applications. Typical additive manufacturing methods of PCL structures for tissue engineering applications either require
harsh organic solvents or are only capable of producing relatively large feature sizes, which are
not compatible with some of the desired applications. Electrohydrodynamic jet (e-jet) printing, an
additive manufacturing process which uses an electric field to induce jetting from a microcapillary
nozzle, is an attractive method for producing PCL tissue engineering structures due to the achievable resolution and the ability to print highly viscous inks. In this work, experimental investigation
into the ability to print pure, molten PCL using the e-jet process is carried out. A characterization
of the process inputs that yield suitable printing regimes is presented. Demonstration of the achievable resolution with e-jet printing is presented in the form of printed, high-resolution structures.",,,,,,
"['Gillo, M.', 'Kruth, J.-P.', 'Vanherck, P.']",2019-10-09T16:02:39Z,2019-10-09T16:02:39Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76146', 'http://dx.doi.org/10.26153/tsw/3235']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Recoating,High-Speed Curtain Recoating for Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ff52b2b8-de20-4bff-8a5d-047fa8f9c1cd/download,,"The University of Leuven uses a liquid curtain recoating system for resin deposition in
stereolithography. This system deposits new liquid layers of photo-polymer by means of a liquid
curtain travelling over the build vat. Experiments have been carried out to increase the speed of the
liquid curtain while depositing a layer. Speeds up to 1.2 m/s, and accelerations up to 1 g have been
tested successfully, meaning that it is possible to coat high-quality layers of 75 µm thickness with
this recoating technique. However, the curtain restores too slowly after acceleration. This paper
discusses possible reasons and tries to formulate adequate solutions. Possible solutions consist in
controlling small pressure differences in the curtain’s neighbourhood. A solution to this problem
is necessary, as to make the travelling length of the curtain, and so the machine length acceptable
with respect to the dimensions of the build vat.",,,,,,
"Levy, Richard A.",2018-10-03T15:31:42Z,2018-10-03T15:31:42Z,1994,Mechanical Engineering,doi:10.15781/T2X05XX8G,http://hdl.handle.net/2152/68647,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Medical imaging', 'Craniofacial CT Imaging', '3D Reconstruction']",Histogram - Based Algorithm for Semiautomated Three-Dimensional Craniofacial Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8eab29a8-5cc2-47b9-94b9-0770c6b597c5/download,,"Volume averaging artifacts in medical imaging result from voxel occupancy by
more than one tissue type and, with anisotropic voxels, may be decreased by
changing the imaging plane orientation relative to the target tissue and/or by
decreasing slice thickness.1
In craniofacial CT imaging, volume averaging artifact becomes significant in areas
ofthin bone such as the orbital walls and auditory ossicles. These regions are
customarily imaged using multiple scan planes and the thinnest slices possible to
reduce such artifacts. In three-dimensional craniofacial imaging, these same
parameters may be controlled to reduce partial volume averaging, but areas of bone
""drop-out"" (also called pseudoforamina) are commonly present secondary to a
paradoxical inability to lower thresholds without including unwanted background
tissues. At present, the optimal solution to this problem is achieved by manually
(and often painstakingly) drawing a region of interest around tissues presumed to
contain volume averaged target density voxels and lowering thresholds to include
these voxels in the 3D reconstruction, one CT slice at a time.
Recently, anatomic modeling technologies have demonstrated the feasibility of
assembling particulate hydroxyapatite (SYnthetic bone) into detailed craniofacial
models of high anatomic accuracy, theoretically suitable for in vivo implantation
(work in progress with the Department of Mechanical Engineering, University of
Texas at Austin.) These modeling systems, such as stereolithography and selective
laser sintering, operate as do 3D imaging workstations, using thresholds to
198
include/exclude pixels from CT data sets in the modeling process. However, the
user interactive capabilities ofsuch technologies may be limited such that manual
tracing ofregions of volume averaged thin bone is not possible. Drop-out artifacts
in models so generated would be potentially larger than on corresponding 3D
images where user input could reduce these artifacts. To circumvent this inability to
manually correct volume averaging artifacts on anatomic modeling systems, and to
relieve the intensive oPerator input required to otherwise achieve this goal on 3D
imaging software, a histogram-based algorithm for semiautomated threedimensional
craniofacial modeling was develoPed.",,,,,,
"['Lorenz, Adam M.', 'Sachs, Emanuel M.', 'Allen, Samuel M.', 'Cima, Michael J.']",2019-10-09T16:10:22Z,2019-10-09T16:10:22Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76149', 'http://dx.doi.org/10.26153/tsw/3238']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Infiltration,Homogeneous Metal Parts by Infiltration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/300a7741-c6ff-4517-8021-9192e225ec34/download,,"Infiltration of powdered metal parts made by SFF processes enables densification with
negligible dimensional change, but typically uses a dissimilar infiltrant material resulting in poor
corrosion resistance, machinability, and a heterogeneous composition inconducive to
certification for critical applications. A new approach called transient liquid-phase infiltration is
described using an infiltrant composition similar to that of the powder skeleton, but containing a
melting point depressant. Upon infiltration, the liquid undergoes diffusional solidification at
infiltration temperature and eventually the composition becomes homogeneous. Parts over 20
cm tall have been fabricated through careful selection of skeleton and infiltrant compositions,
skeleton powder size, and infiltration technique. The work presented in this paper uses a nickelsilicon alloy to infiltrate a skeleton of pure nickel powder.","This research was sponsored by the Office of Naval Research, Contract #N00014-99-1-1090.",,,,,
"['Johanson, Roy', 'Kikuchi, Noboru', 'Papalambros, Panos']",2018-05-03T18:42:28Z,2018-05-03T18:42:28Z,1993,Mechanical Engineering,doi:10.15781/T2FB4X41H,http://hdl.handle.net/2152/65057,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering and Applied Mechanics', 'MAXWELL', 'Topology', 'Recursive Mask and Deposit']",Homogenization Design and Layered Manufacturing of a Lower Control Arm in Project MAXWELL,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ad2234cb-d3db-4370-b4d5-68260c30340c/download,,"We briefly describe a new methodology for the design and manufacture of mechanical components and demonstrate the process for the design of an automobile
suspension component. The methodology is a unique coupling between advanced
technologies for product design and manufacture, which leads to the rapid realization of
superior products. The concurrent design and analysis strategy yields information about
the optimal structural layout, as well as details about the material composition. The
fabrication of such designs requires unconventional manufacturing processes, such as
layered manufacturing. Project MAXWELL, therefore, offers the possibility for the
integration of layered manufacturing into the mainstream product development and
fabrication process.",,,,,,
"['Buls, S.', 'Clijsters, S.', 'Kruth, J.-P.']",2021-10-12T19:40:11Z,2021-10-12T19:40:11Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88725', 'http://dx.doi.org/10.26153/tsw/15659']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'PID feedback controller', 'homogenous melt pool intensity distribution', '2D intensity maps', 'laser scanning', 'melt pool intensity distribution']",Homogenizing the Melt Pool Intensity Distribution in the SLM Process through System Identification and Feedback Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b39a4667-f62e-4a86-a332-464f859dcd50/download,University of Texas at Austin,"The common scanning strategies in Selective Laser Melting lead to an inhomogeneous melt pool intensity distribution throughout the different layers and scan tracks. This results in various defects such as porosity at the edges, residual stresses, or even excessive warping and delamination. In this research, this issue is resolved by the implementation of an on-line and real-time PID feedback controller. The PID feedback controller will alter the laser power based upon the melt pool intensity resulting in a homogeneous intensity distribution throughout the different scan tracks and layers. 2D intensity maps can be generated from the on-line monitoring system during the production of a benchmark part and will serve as validation for the PID feedback controller.",,,,,,
"['Baumers, M.', 'Tuck, C.', 'Dickens, P.', 'Hague, R.']",2021-10-12T21:03:59Z,2021-10-12T21:03:59Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88741', 'http://dx.doi.org/10.26153/tsw/15675']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['multi-material Additive Manufacturing', 'Additive Manufacturing', 'material jetting', 'build-time', 'energy consumption', 'production cost', 'photopolymers']",How Can Material Jetting Systems Be Upgraded for More Efficient Multi-Material Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a294c41-d03e-4fd7-82da-676986ba3cd4/download,University of Texas at Austin,"Multi-material Additive Manufacturing (AM) platforms are able to build up
components from multiple materials in a single layer-by-layer process. It is expected that this
capability will enable the manufacturing of functional structures within products, such as
conductive tracks or optical pathways, resulting in radically novel products with
unprecedented degrees of functional density.
An important variant of commercially available multi-material AM technology is material
jetting, which is currently in commercial use for the manufacture of prototypes and design
studies. This paper presents a detailed process model of build-time, energy consumption and
production cost for the Stratasys Objet 260 Connex system, analyzing the contemporaneous
deposition of two different types of photopolymers (Veroclear RGD810 and Tangoblack
FLX973). By using this process model to anticipate the effects of various upgrades to the
investigated system, such as a larger build volume and a higher deposition speed, this
forward-looking paper explores pathways to enhancing the value proposition of such multi-material systems through incremental technology improvement.",,,,,,
"['Stevenson, A.', 'Baumers, M.', 'Segal, J.', 'Macdonell, Sarah']",2021-11-08T21:59:32Z,2021-11-08T21:59:32Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90053', 'http://dx.doi.org/10.26153/tsw/16974']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['cost impact', 'cost analysis', 'part consolidation', 'additive manufacturing', 'PC', 'AM']",How Significant is the Cost Impact of Part Consolidation Within AM Adoption?,Conference paper,https://repositories.lib.utexas.edu//bitstreams/52d0b8f1-cf14-4a39-9085-4e48785bec54/download,University of Texas at Austin,"Successful implementation of advanced manufacturing technologies requires a robust
pre-installation phase involving evaluation and justification of potential benefits. However,
despite part consolidation (PC) being described as one of the major benefits of additive
manufacturing (AM), there has been very little quantification of its potential impact on costs.
This makes it difficult for organisations to consider all the benefits of AM adoption. A case
study research approach has been used to develop an empirical cost model based on PC for the
development and production stages of a product, which can be adapted by organisations during
their own pre-installation stage. The case studies involve re-design of existing sub-assemblies
within a laboratory instrument producer, and the resulting cost model has been trialed using
empirical data. The results show that AM has the potential to considerably reduce part count
by up to 93% and associated costs by up to 85%. The significant cost saving occurs where PC
results in the consolidation of numerous components thereby eliminating considerable cost
elements.",,,,,,
"['Weflen, E.D.', 'Peters, F.E.', 'Frank, M.C.']",2023-04-05T13:42:42Z,2023-04-05T13:42:42Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117773', 'http://dx.doi.org/10.26153/tsw/44652']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Hybrid Additive and Subtractive Manufacturing of Direct-Heated Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47308ae5-19dc-44ff-b237-e3650cc74c0a/download,,"Pre-heating is a common requirement for production tooling in applications such as 
compression and injection molding. While the carbon fiber reinforcements commonly used in 
large-area additive manufacturing improve the thermal conductivity of polymers, they are still far 
below that of metal tooling. This study presents a method for direct, local Joule heating of tooling 
without the need for additional heating elements. A current is induced in the composite tooling, 
resulting in resistance heating of the substrate. High conductivity material is locally embedded to 
achieve local control over the heating characteristics. Embedding of the conductive material is 
accomplished by selectively switching material compositions during the printing process. 
Demonstration tooling is produced using hybrid additive and subtractive manufacturing using an 
AMBIT XTRUDE in a HAAS machining center and evaluated with thermal imaging. Direct 
heating of tooling expands the potential applications of additive manufacturing by overcoming the 
challenges of low thermal conductivity materials.",,,,,,
"['Aremu, A.', 'Ashcroft, I.', 'Wildman, R.', 'Hague, R.', 'Tuck, C.', 'Brackett, D.']",2021-10-04T21:38:32Z,2021-10-04T21:38:32Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88356', 'http://dx.doi.org/10.26153/tsw/15295']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'additive manufacturing', 'adaptive meshing strategy', 'bidirectional evolutionary structural optimization']",A Hybrid Algorithm for Topology Optimization of Additive Manufactured Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/913c9e8b-9f84-4df0-ba63-2b73b06004c7/download,University of Texas at Austin,"Most topology (TO) algorithms involve the penalization of intricate structural features to eliminate manufacturing difficulties. Since additive manufacturing is less dependent on manufacturing
constraints, it becomes necessary to adapt these algorithms for AM. We propose a hybrid algorithm
consisting of an adaptive meshing strategy (AMS) and a modified form of the bidirectional evolutionary structural optimization (BESO) method. By solving a standard cantilever problem, we show
that the hybrid method offers improved performance over the standard BESO method. It is proposed
that the new method is more suitable for optimizing structures for AM in a computational efficient
manner.",,,,,,
"Boudreaux, J.C.",2021-10-19T15:12:40Z,2021-10-19T15:12:40Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89293,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'hybrid automata', 'operational features', 'technical issues']",Hybrid Automata in the Context of Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99d4d6b8-934d-4480-8feb-1d5d746760f1/download,University of Texas at Austin,"To maintain the forward momentum of additive manufacturing technology, it is necessary to thoroughly evaluate
new and potentially useful technological developments in this field. One such development is the intense interest being
directed to the field of hybrid automata (HA). Hybrid automata combine both the discrete processing behavior of finite
automata as well as the continuous, or flow, behavior of dynamical systems. At this point, some important results on hybrid
automata have been obtained, but many open questions remain, including those concerning the decidability of HS
operational procedures. (Recall that decidability is directed to a decision problem, that is, a definite true-or-false response
given by an effective procedure.) Some important decidability results for HAs have been obtained. For example, in
[Henzinger et al.1998] the reachability problem for timed automata (an HA class) has been convincingly shown to be
decidable. However, it should also be noted that subtle and difficult issues have been identified, e.g., [Fraenzle 1999],
[Asarin, Collins, 2005]. This paper will provide a summary review of the operational features of HAs as they might pertain
to additive manufacturing, and then briefly consider the following technical issues: (i) are the classical models of the real
numbers best suited to deal with the necessarily approximate measures of physical systems or would non-standard analysis
of [Robinson 1996] be a better fit; and (ii) would the introduction of “noisy semantics” and finite arithmetic precision,
following [Freidlin, Wentzell 1984], be a better work around?",,,,,,
"['Wade, Charles', 'Borish, Michael']",2023-01-26T14:39:54Z,2023-01-26T14:39:54Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117308', 'http://dx.doi.org/10.26153/tsw/44189']",eng,2022 International Solid Freeform Fabrication Symposium,Open,hybrid curve fitting,Hybrid Curve Fitting for Reducing Motion Commands in Object Construction,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6748fff8-633b-4d95-9ee8-7f087e7499c5/download,,"Existing slicing software for additive manufacturing typically requires a triangulated 
mesh as its input. Triangulated meshes are approximate representations of exact CAD models. 
Despite the loss in dimensional accuracy, triangulated meshes are used because they are 
computationally easier to cross-section and offset than the exact geometry in CAD format. 
When a triangulated object is prepared, the resulting machine instructions include only 
linear motion commands. Numerous modern motion controllers can move in arc and spline 
motions; however, the absence of slicing software that supports curvature prevents these 
commands from being leveraged. To address this limitation, this paper presents a method for 
the hybrid reconstruction of arcs and splines as a post-processing step to traditional slicing. 
This method can greatly reduce the number of motion commands required to construct an 
object by printing smooth curved surfaces. This concise representation of tool-pathing allows 
for more even extrusion and is computed without a major impact on slicing time.",,,,,,
"['Zhang, Haiou', 'Xie, Yang', 'Rui, Daoman', 'Wang, Guilan']",2021-10-07T18:13:22Z,2021-10-07T18:13:22Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88497', 'http://dx.doi.org/10.26153/tsw/15431']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['new AM method', 'hybrid deposition and micro rolling', 'HDMR', 'metallic parts', 'high performance', 'efficiency and low cost']",Hybrid Deposition and Micro Rolling Manufacturing Method of Metallic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d192824d-b46f-490d-a7bd-f1adb3b41af3/download,University of Texas at Austin,"To conquer the bottleneck problems of cracking, deformation, low accuracy and performance in
existing additive manufacturing (AM) process, a new hybrid direct manufacturing method of metallic
parts which integrates freeform deposition with micro rolling is proposed in this paper. The principle,
devices and simulations are introduced and the comparison with Freeform Deposition Fabrication
method are made through experiments, showing that hybrid manufactured parts has
distinctive features of higher accuracy and better microstructures. The tensile strength is increased by
33% for stainless steel while the elongation percentage is improved more than 2 times. By using the
Φ1.6mm wire in a feed rate of 1060mm/min, the deposition rate can get to 10kg/h. This method is
appropriate for fabricating large-scale metal parts with outstanding quality, efficiency and low cost.",,,,,,
"['Baldwin, Martha', 'Meisel, Nicholas A.', 'McComb, Christopher']",2024-03-27T15:42:27Z,2024-03-27T15:42:27Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124486', 'https://doi.org/10.26153/tsw/51094']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['multi-lattice transition', 'geometry autoencoder', 'property autoencoder', 'additive manufacturing']",Hybrid Geometry/Property Autoencoders for Multi-Lattice Transitions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc4e6968-ba6f-4da4-adca-75bd2a43917f/download,University of Texas at Austin,"Additive manufacturing has revolutionized structural optimization by enhancing component
strength and reducing material requirements. One approach used to achieve these improvements
is the application of multi-lattice structures. The performance of these structures heavily relies on
the detailed design of mesostructural elements. Many current approaches use data-driven design
to generate multi-lattice transition regions, making use of models that jointly address the geometry
and properties of the mesostructures. However, it remains unclear whether the integration of
mechanical properties into the data set for generating multi-lattice interpolations is beneficial
beyond geometry alone. To address this issue, this work implements and evaluates a hybrid
geometry/property machine learning model for generating multi-lattice transition regions. We
compare the results of this hybrid model to results obtained using a geometry-only model. Our
research determined that incorporating physical properties decreased the number of variables to
address in the latent space, and therefore improves the ability of generative models for developing
transition regions of multi-lattice structures.",,,,,,
"['Coronel, Jose L. Jr', 'Billah, Kazi Md Masum', 'Acosta Carrasco, Carlos F.', 'Barraza, Sol A.', 'Wicker, Ryan B.', 'Espalin, David']",2021-11-09T15:53:34Z,2021-11-09T15:53:34Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90102', 'http://dx.doi.org/10.26153/tsw/17023']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['hybrid manufacturing', 'fused deposition modeling', 'power electronics', 'kapton coated wire', 'polycarbonate']",Hybrid Manufacturing with FDM Technology for Enabling Power Electronics Component Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e882235-e6b9-45cd-bc7c-ed49f9d1624a/download,University of Texas at Austin,"The introduction of Kapton coated wires within a printed substrate presents the opportunity
to design and fabricate power electronics components. Preventing dielectric breakdown of the
printed substrate, the ultrasonic embedding approach enables complex geometrical embedding
through customized software. This work presents the effective embedding of large diameter (14
AWG) kapton coated litz wire into polycarbonate (PC) substrate. Custom software allowed for
generation of embedding toolpaths directly from the CAD model of the designed coupon. Results
showed the most successful embedding paths were circular pre-formed cavities. Through
characterization of a myriad of printed samples, an approach was developed for embedding large
diameter wire. Through the use of the Foundry Multi3D System, the increased complexity of
embedded electronic parts can further impulse the implementation of hybrid additive
manufacturing in large scale applications.",,,,,,
"['Medina, Frank', 'Lopes, Amit', 'Inamdar, Asim', 'Hennessey, Robert', 'Palmer, Jeremy', 'Chavez, Bart', 'Davis, Don', 'Gallegos, Phil', 'Wicker, Ryan']",2020-02-20T19:42:21Z,2020-02-20T19:42:21Z,8/23/05,Mechanical Engineering,,https://hdl.handle.net/2152/80043,eng,2005 International Solid Freeform Fabrication Symposium,Open,"['commercial stereolithography machine', 'rapid prototyping', 'direct-write']",Hybrid Manufacturing: Integrating Direct Write and Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9b154873-8548-4daf-b188-ea5d3804ac59/download,,"A commercial stereolithography (SL) machine was modified to integrate fluid dispensing or
direct-write (DW) technology with SL in an integrated manufacturing environment for
automated and efficient hybrid manufacturing of complex electrical devices, combining threedimensional (3D) electrical circuitry with SL-manufactured parts. The modified SL system
operates similarly to a commercially available machine, although build interrupts were used to
stop and start the SL build while depositing fluid using the DW system. An additional linear
encoder was attached to the SL platform z-stage and used to maintain accurate part registration
during the SL and DW build processes. Individual STL files were required as part of the
manufacturing process plan. The DW system employed a three-axis translation mechanism that
was integrated with the commercial SL machine. Registration between the SL part, SL laser and
the DW nozzle was maintained through the use of 0.025-inch diameter cylindrical reference
holes manufactured in the part during SL. After depositing conductive ink using DW, the SL
laser was commanded to trace the profile until the ink was cured. The current system allows for
easy exchange between SL and DW in order to manufacture fully functional 3D electrical
circuits and structures in a semi-automated environment. To demonstrate the manufacturing
capabilities, the hybrid SL/DW setup was used to make a simple multi-layer SL part with
embedded circuitry. This hybrid system is not intended to function as a commercial system, it is
intended for experimental demonstration only. This hybrid SL/DW system has the potential for
manufacturing fully functional electromechanical devices that are more compact, less expensive,
and more reliable than their conventional predecessors, and work is ongoing in order to fully
automate the current system.",,,,,,
"['Liravi, Farzad', 'Jacob-John, Varun', 'Toyserkani, Ali', 'Vlasea, Mihaela']",2021-11-04T18:12:42Z,2021-11-04T18:12:42Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89993', 'http://dx.doi.org/10.26153/16914']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'binder jetting', 'micro-deposition', 'hybrid printing', 'binder distribution', 'silicone materials']",A Hybrid Method for Additive Manufacturing of Silicone Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/adcc6344-6bb7-48d8-ab3e-2ca671f2bab2/download,University of Texas at Austin,"Developing an additive manufacturing (AM) technique for fabrication of complex-shaped
silicone structures is a challenging task due to difficulties in layer-wise dispensing and stacking of
such non-Newtonian viscous materials. The need for such a technique becomes apparent when
surveying the ever-increasing applications of the silicone polymer in the biomedical sector. In this
research, a hybrid powder-bed binder-jetting (PBBJ) and material micro-dispensing method
(hybrid-PBBJ) is employed for the production of structures from silicone powder for the first time.
The conventional PBBJ technique is coupled with a micro-syringe dispensing mechanism to make
the layer-by-layer infiltration of fluidic silicone rubber into the silicone powder possible. Standard
cylindrical (5 mm (D) ´ 3 mm (H)) and thin walled (10 mm (L) ´ 1.8 mm (H)) artefacts were
manufactured as part of a design of experiment (DOE) and as a proof of concept. The AM parts
were characterized in terms of geometry, porosity and mechanical performance. The DOE results
will be deployed to subsequent manufacturing of complex structures.",,,,,,
"['Ferreira, J. C.', 'Madureira, H.', 'Beira, R.']",2020-02-27T19:28:24Z,2020-02-27T19:28:24Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80094', 'http://dx.doi.org/10.26153/tsw/7115']",eng,2006 International Solid Freeform Fabrication Symposium,Open,rapid product development,Hybrid Prototypes to Assist Modeling Automotive Seats,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2388b2e-fc44-4613-b0af-34a3cb2f6d85/download,,"The development of new modular seats is an important issue in the automotive industry.
However, is very time consuming and costly. Virtual models and hybrid prototypes could
accelerate the car seats development process. The hybrid prototypes are mainly manufactured by
rapid prototyping with multi materials. The objective of this paper is to establish a methodology
to develop innovative lightweight multi-functional, modular car seats to be used in Multi-Purpose
Vehicles (MPV), by means of FEA simulation and rapid prototyping additive/subtractive
technologies utilizing multi materials. A case study is presented to validate the developed
methodology. The manufactured hybrid prototype’s reproduces the main functionalities of the
MPV modular seat, namely its three key positions: normal, stored and table.",,,,,,
"['Frank, Matthew C.', 'Peters, Frank E.', 'Luo, Xiaoming', 'Meng, Fanqi', 'Petrzelka, Joseph']",2021-09-28T18:21:40Z,2021-09-28T18:21:40Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88145', 'http://dx.doi.org/10.26153/tsw/15086']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['sand castings', 'Rapid Pattern Manufacturing']",A Hybrid Rapid Pattern Manufacturing System for Sand Castings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b71f75c4-f260-4fdb-aabb-c253c312cfc7/download,University of Texas at Austin,"This paper presents a Rapid Pattern Manufacturing system developed for the sand casting process. It
involves both additive and subtractive techniques whereby slabs are sequentially bonded and milled using
layered toolpaths. As such, patterns are grown in a bottom-up fashion, both eliminating the need for
multi-axis operations and allowing small features in deep cavities. Similar approaches exist in the
literature; however, this system is specifically targeted at large wood and urethane sand casting patterns.
This method introduces a novel support structure approach by integrating a flask into the pattern build
process. We also present adaptive slicing algorithms that optimally place layer transitions to avoid thin
sections near flats, peaks, and valleys or where interaction with chemically bonded sand could be
problematic. The system has been implemented in an automated machine capable of producing patterns
in excess of several thousand pounds. Preliminary testing of the system in the development of next
generation military equipment is presented in a case study.",,,,,,
"['Cohen, Daniel L.', 'Lipton, Jeffrey I.', 'Cutler, Meredith', 'Coulter, Deborah', 'Vesco, Anthony', 'Lipson, Hod']",2021-09-29T20:23:03Z,2021-09-29T20:23:03Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88213', 'http://dx.doi.org/10.26153/tsw/15154']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'food', 'food production', 'culinary field', 'hydrocolloids', 'flavor agents', 'molecular gastronomy']",Hydrocolloid Printing: A Novel Platform for Customized Food Production,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac256b22-d43d-434c-9162-05fefb14aa00/download,University of Texas at Austin,"Solid Freeform Fabrication (SFF) of food has the potential to drastically impact both culinary
professionals and laypeople; the technology will fundamentally change the ways we produce and
experience food. Several imposing barriers to food-SFF have been overcome by recent open-source printing projects. Now, materials issues present the greatest challenge. While the
culinary field of molecular gastronomy can solve many of these challenges, careful attention
must be given to contain materials-set bloat. Using a novel combination of hydrocolloids
(xanthium gum and gelatin) and flavor agents, texture and flavor can be independently tuned to
produce printing materials that simulate a broad range of foods, with only a minimal number of
materials. In addition to extensively exploring future applications of food-SFF, we also present a
rigorous proof-of-concept investigation of hydrocolloids for food-SFF. A two-dimensional
mouthfeel rating system was created (stiffness vs. granularity) and various hydrocolloid mixtures
were characterized via an expert panel of taste testers.",,,,,,
"['Arcaute, Karina', 'Ochoa, Luis', 'Mann, Brenda', 'Wicker, Ryan']",2020-02-24T15:17:24Z,2020-02-24T15:17:24Z,8/23/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80080', 'http://dx.doi.org/10.26153/tsw/7101']",eng,2005 International Solid Freeform Fabrication Symposium,Open,stereolithography,Hydrogels in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/298949ad-1be9-4f0f-8451-742243587600/download,,"The use of stereolithography (SL) for fabricating complex three-dimensional (3D) tissue
engineered scaffolds of aqueous poly(ethylene glycol) (PEG) hydrogel solutions is described.
The primary polymer used in the study was PEG-dimethacrylate (PEG-dma) with an average
molecular weight (MW) of 1000 in distilled water with the photoinitiator Irgacure 2959 (I-2959).
Successful layered manufacturing (LM) with embedded channel architecture required
investigation of the photopolymerization characteristics of the PEG solution (measured as
hydrogel thickness or cure depth) as a function of photoinitiator concentration and laser energy
dosage for a specific photoinitiator type and polymer concentration in solution. Hydrogel
thickness was a strong function of PI concentration and energy dosage. Curves of hydrogel
thickness were utilized to successfully plan, perform, and demonstrate layered manufacturing of
highly complex hydrogel scaffold structures, including structures with internal channels of
various orientations. Successful fabrication of 3D, multi-layered bioactive PEG scaffolds
containing cells was accomplished using a slightly modified commercial SL system (with 325
nm wavelength laser) and procedure. Human dermal fibroblast (HDF) cells were encapsulated in
PEG hydrogels using small concentrations (~ 5 mg/ml) of acryloyl-PEG-RGDS (MW 3400)
added to the photopolymerizable PEG solution to promote cell attachment. HDF cells were
combined with the PEG solution, photocrosslinked using SL, and successfully shown to survive
the fabrication process. The combined use of SL and photocrosslinkable biomaterials such as
PEG makes it possible to fabricate complex 3D scaffolds that provide site-specific and tailored
mechanical properties (i.e., multiple polymer materials) with a polymer matrix that allows
transport of nutrients and waste at the macroscale and facilitates cellular processes at the
microscale through precisely placed bioactive agents.",,,,,,
"['French, M.R.', 'Yarberry, W.A. III', 'Pawlowski, A.E.', 'Shyam, A.', 'Splitter, D.A.', 'Elliott, A.M.', 'Carver, J.K.', 'Cordero, Z.C.']",2021-11-04T20:53:53Z,2021-11-04T20:53:53Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90025', 'http://dx.doi.org/10.26153/16946']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['A356', '316L', 'stainless steel', 'hypervelocity impact', 'interpenetrating phase composite', 'additive manufacture']",Hypervelocity Impact of Additively Manufactured A356/316L Interpenetrating Phase Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91024cb5-e794-4a65-a696-43035c7c9600/download,University of Texas at Austin,"We have examined the hypervelocity impact response of targets made from monolithic
A356 and 316L stainless steel, as well as an additively manufactured A356/316L interpenetrating
phase composite. 1.9 mm diameter spherical projectiles made from 2017 aluminum were fired at
velocities of 5.9-6.1 km/s, allowing for the observation of multiple types of macro- and
microstructural damage within each target. The macroscopic cratering damage to the A356/316L
composite resembles that of the A356, but observations of both the cross section and the
microstructural damage suggest that the A356/316L composite may be more resistant to spalling
than A356 shielding with the same areal density.",,,,,,
"['Seltzer, D.', 'Schiano, J.L.', 'Nassar, A.R.', 'Reutzel, E.W.']",2021-10-28T20:02:49Z,2021-10-28T20:02:49Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89687,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['optical illumination', 'image processing', 'melt-pool width', 'build height', 'real-time control', 'melt pool geometry', 'directed energy deposition', 'additive manufacturing']",Illumination and Image Processing for Real-Time Control of Directed Energy Deposition Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e81070b-0b19-4bdd-aadf-2295e92a3b74/download,University of Texas at Austin,"This paper describes the optical setup and image processing required to estimate melt-pool width
and build height for real-time control of melt-pool geometry in directed energy deposition additive
manufacturing. To overcome optical interference from plasma emissions and laser interactions,
the melt-zone is imaged using laser illumination. A single camera, fixed to the processing laser,
views the laser interaction zone and provides images for estimating melt-zone width and build
height. Using a bandpass filter and a single aspheric lens, the camera system provides sufficient
magnification and depth of field to achieve a 1-mil (25.4 µm) resolution. Maintaining melt-zone
geometry within desired tolerances requires an image acquisition and processing rate on the order
of 100 frames per second. This bandwidth is achieved by a Camera Link camera and field-programmable gate array that implements algorithms for estimating melt-pool width and build
height. The design and experimental verification of the camera, illumination, and processing
systems are discussed.",,,,,,
"['Lang, Andrew', 'Ortiz Rios, Cesar', 'Newkirk, Joseph', 'Landers, Robert G.', 'Castle, James', 'Bristow, Douglas A.']",2021-12-07T18:01:22Z,2021-12-07T18:01:22Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90739', 'http://dx.doi.org/10.26153/tsw/17658']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['image registration', 'matching error', '2D image', '3D image', '301L', 'stainless steel', 'laser powder bed fusion']",Image Registration and Matching Error in 2D and 3D for Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/941818e2-4d10-43d0-857a-c3dbf8b019fb/download,University of Texas at Austin,"This work outlines a method to register 2D and 3D images taken post-process and in situ
from 301L stainless steel parts printed by Laser Powder Bed Fusion. The process uses
DREAM.3D, an open-source software that provides for data transport in a non-proprietary format.
The Robust Automatic Threshold selection technique is used to create a boundary point cloud of
the part from each image. The Iterative Closest Point technique is applied to the point clouds for
both 2D images and 3D image stacks to create an affine transformation matrix for registration.
Multiple 2D SEM images of the same sampled layer are taken under different settings and imaging
conditions and registered to a common target. Images from post-process X-ray Computed
Tomography and an in situ short-wave infrared camera create 3D image stacks, which are directly
registered in 3D space. Registration accuracy is validated by creating a correspondence list of the
closest point in the registered point clouds and the matching error is calculated using mean average
error. Mean average error is computed using point-to-point and point-to-plane methods; the pointto-plane method is shown to be more reliable. Finally, the registered 3D images are down sampled
to the lower resolution image dimensions creating arrays of in situ and post-process data at the
same resolution.",,,,,,
"['Hauser, C.', 'Lewis, D. M.', 'Dunschen, M.', 'Egan, M.', 'Sutcliffe, C.']",2020-03-09T14:21:11Z,2020-03-09T14:21:11Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80182', 'http://dx.doi.org/10.26153/tsw/7201']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Spiral growth manufacturing,Image Transformations and Printing of Plaster Layers in Spiral Growth Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a74fed63-7f95-40d7-9876-2f26b1876fce/download,,"Spiral growth manufacturing (SGM) is a high speed rapid manufacturing technique in
which objects are built up, layer by layer, by simultaneously depositing, levelling and selectively
consolidating thin powder layers onto a rotating build platform. The size and position of the
jetted droplets are mapped by the position and greyscale level of pixels within an 8 bit greyscale
bitmap image. This paper reports on the development of software in which mathematical
algorithms apply geometric transformations to images in preparation for printing onto a rotating
substrate. In support of this work, dimensional accuracy measurements of printed images and
methods to correct radial print density variations are reported. The accuracy of printed images
were found to be within ±0.2mm of their predicted size. The experimental work is briefly
extended to the direct printing of plaster layers, formed by mixing two reactive ink solutions.",,,,,,
"['He, Li', 'Fei, Fan', 'Wang, Wenbo', 'Song, Xuan']",2021-11-15T22:16:35Z,2021-11-15T22:16:35Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90291', 'http://dx.doi.org/10.26153/tsw/17212']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['immiscible interface', 'direct metal drawing', 'colloidal suspension', 'self-stabilization', 'heat treatment']",Immiscible-Interface Assisted Direct Metal Drawing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2093d106-c698-4742-9240-a8ee0d13e77d/download,University of Texas at Austin,"State-of-the-art metal additive manufacturing (AM) techniques construct a three-dimensional (3D) structure through sintering or melting dry metal powders in a layer-by-layer
fashion, which consequently results in some typical manufacturing defects in the final structure,
such as residual stress and highly-orientated microstructures. To overcome these defects, we
present a new low-cost metal AM process, named Immiscible-interface assisted Direct Metal
Drawing (II-DMD), which fabricates self-supported and isotropic 3D metal structures by
continuously extruding a metal colloidal suspension within a second immiscible matrix colloidal
suspension. The shape of the metal colloidal suspension is stabilized due to the presence of an
immiscible interface between the two colloidal suspension systems. Dense metal structures can be
achieved via post-consolidation of the self-stabilized metal-matrix systems, including liquid-phase
drying and metal-phase sintering. In this article, the immiscible-interface-assisted self-stabilization
mechanism is studied. The post-consolidation processes are discussed. Several test cases were
fabricated and characterized.",,,,,,
"['Brennan-Craddock, J. P. J.', 'Bingham, G. A.', 'Hague, R. J. M.', 'Wildman, R. D.']",2020-03-11T15:26:53Z,2020-03-11T15:26:53Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80251', 'http://dx.doi.org/10.26153/tsw/7270']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Impact Absorbent Rapid Manufactured Structures (IARMS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/0301e9fe-4d31-4cc1-936c-2e1cecdba437/download,,"Rapid Manufacturing (RM) is increasingly becoming a viable manufacturing process due
to dramatic advantages that it facilitates in the area of design complexity. Through the
exploration of the design freedom afforded by RM, this paper introduces the concept and initial
research surrounding Impact Absorbent Rapid Manufactured Structures (IARMS), with an
application in sports personal protective equipment (PPE). Designs are based on the cellular
structure of foams; the inherent advantages of the cellular structure are used as a basis to create
IARMS that have the potential to be optimised for a specific impact absorbent response. The
paper provides some initial results from compression testing",,,,,,
"['Lindemann, C.', 'Jahnke, U.', 'Moi, M.', 'Koch, R.']",2021-10-12T18:50:56Z,2021-10-12T18:50:56Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88718', 'http://dx.doi.org/10.26153/tsw/15652']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'lifecycle costs', 'costing model', 'product lifecycle']",Impact and Influence Factors of Additive Manufacturing on Product Lifecycle Costs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fbdf45f1-2dcf-46e8-839e-e1c41aec40f1/download,University of Texas at Austin,"At first sight the direct costs of Additive Manufacturing (AM) seem too high in comparison to
traditional manufacturing. Considering the whole lifecycle costs of parts changes the point of
view. Due to the modification of the new production process and new supply chains during a
parts lifecycle, producing companies can strongly benefit from AM. Therefore, a costing
model for assessing lifecycle costs with regard to specific applications and branches has been
developed. The costing model represents the advantages of AM monetary. For the evaluation
of this model and the influence factors, different case studies have been performed including
different approaches in part redesign. Deeper research is and will be carried out with respect
to the AM building rates and the comparability of various AM machines, as these facts are
hardly comparable for end users. This paper will present the methodology as well as the
results of the case studies conducted over the whole product lifecycle.",,,,,,
"['Wu, Y.', 'Hermes, J.', 'Verbelen, L.', 'Yang, L.']",2021-11-30T21:35:04Z,2021-11-30T21:35:04Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90556', 'http://dx.doi.org/10.26153/tsw/17475']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['cellular structures', 'thermoplastic polyurethane', 'TPU', 'impact energy absorption', 'powder bed fusion']",Impact Energy Absorption Ability of Thermoplastic Polyurethane (TPU) Cellular Structures Fabricated via Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e961562-add5-4f53-a2ec-8b3f9e63bacc/download,University of Texas at Austin,"In this study, experimental based investigation was carried out with various cellular
structure designs realized using a developmental thermoplastic polyurethane (TPU) fabricated by
powder bed fusion process, in the attempt to evaluate the effectiveness of impact energy absorption
design with cellular structures when combined with favorable materials. Various cellular designs
including the re-entrant auxetic, double-arrow auxetic, octet-truss, BCC, octahedral, diamond and
double bow-tie were designed and evaluated. Pendulum-rebound resilience testing and drop-weight impact testing were carried out with each designs, and the effective energy absorption
capabilities of these designs were compared. The results from this study provide some initial
insights into the design of TPU-based cellular structures for energy absorption applications that
could benefit the establishment of more comprehensive knowledge base in this area.",,,,,,
"['Corbin, David J.', 'Nassar, Abdalla R.', 'Reutzel, Edward W.', 'Kistler, Nathan A.', 'Beese, Allison M.', 'Michaleris, Pan']",2021-10-27T21:27:58Z,2021-10-27T21:27:58Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89620,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'laser cladding', 'Ti-6Al-4V', 'additive manufacturing', 'distortion', 'in situ measurements']",Impact of Directed Energy Deposition Parameters on Mechanical Distortion of Laser Deposited Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ebc74849-3b3b-4596-b054-fc57782a5f49/download,University of Texas at Austin,"The effects of laser-based powder-fed directed energy deposition processing parameters
on the distortion of deposited Ti-6Al-4V parts are assessed through in situ monitoring.
Experiments were conducted wherein substrate thickness, deposition thickness, and initial
substrate temperature were varied in order to investigate their effects on distortion. Correlations
of process parameters to the mechanical characteristic were also developed, uncovering some of
the driving mechanisms of the measured characteristic. This work highlights the impact of
substrate preheating on distortion. Most notably, the effect of initial substrate temperature on
distortion depended on the size of the substrate. On thin substrates, preheating reduced the total
amount of distortion. However on thick substrates, preheating increased the amount of distortion.
Techniques to mitigate the unwanted mechanical defect are discussed.",,,,,,
"['Sinha, Swapnil', 'Meisel, Nicholas A.']",2021-11-30T19:13:48Z,2021-11-30T19:13:48Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90517', 'http://dx.doi.org/10.26153/tsw/17436']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['material extrusion additive manufacturing', 'cavity design', 'toolpath design', 'thermal history']",Impact of Embedding Cavity Design on Thermal History between Layers in Polymer Material Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9250ec57-7fb1-40ed-a3ec-e7c8bb97802f/download,University of Texas at Austin,"By pausing an additive manufacturing process in mid-print, it is possible to create
multifunctional structures through strategic insertion of foreign components. However, in polymer
material extrusion, previous research has shown that pausing the build decreases the eventual
strength of the final part, due to cooling between layers. To better predict this part weakness, this
paper seeks to quantify how the toolpath affects the thermal history of a cross-section, thus
impacting the formation of weld strength between printed layers. This is pertinent to in-situ
embedding as different embedded geometries will require different cavity designs, which, in turn,
will affect toolpath design. In-situ thermal measurements are experimentally collected with a
thermocouple at the layer interface of structures with different cavity designs. The weld strength
between layers is then obtained through tensile tests and theoretically evaluated using polymer
weld theory. Results show more accurate predictions of load at failure with this method.",,,,,,
"['Kleijnen, R.G.', 'Schmid, M.', 'Wegener, K.']",2021-11-18T01:39:36Z,2021-11-18T01:39:36Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90396', 'http://dx.doi.org/10.26153/tsw/17317']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['flow aid', 'flowability', 'coalescence', 'polybutylene terephthalate', 'PBT', 'selective laser sintering']",Impact of Flow Aid on the Flowability and Coalescence of Polymer Laser Sintering Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d0b11d9-72ba-4f3e-9ab6-f3e4297cbc89/download,University of Texas at Austin,"Small amounts of nanometer-sized flow aids are typically added to polymer powders
for selective laser sintering to increase flowability. These additives reduce friction between
particles by electrostatic repulsion, leading to better bed density and part properties. The same
repulsion however can hinder particle coalescence in the melt, reducing part density. This study
investigates the effect of different amounts of flow aid on flowability and coalescence. A
polybutylene terephthalate (PBT) powder with spherical morphology, specially designed for
selective laser sintering, is used as a base and ideal model material. The coalescence is
monitored by hot-stage optical microscopy. It was found that with increasing amounts of flow
aid, the flowability could be characterized by three regions; one of low flowability where the
powder contained insufficient flow aid, followed by a sharp transition region towards a high
flowability region, where the flow aid was most effective. Addition of flow aid impacted the
coalescence, which was marked by an increase of the temperature at which the particles started
to melt and flow. At the maximum concentration of 0.5 wt.-% flow aid, the melting of some
particles was delayed, and they remained solid for longer time at temperatures beyond the
melting temperature. The optimum amount of flow aid therefore lies in the plateau region of
high flowability, but before the occurrence of delayed melting.",,,,,,
"['Campbell, R.I.', 'Hodgson, A.R.']",2019-11-20T15:47:50Z,2019-11-20T15:47:50Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78461', 'http://dx.doi.org/10.26153/tsw/5546']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Industrial,The Impact of In-House RP Upon Final Year Industrial Design Student Projects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b09c1056-0b50-4d87-b4b2-e0f1bf7e6499/download,,"A vital part of the Industrial Design and Technology degree course at Loughborough
University is the development of appearance and functional prototypes. Previously, the use of
rapid prototyping (RP) has been fairly limited because of the high cost and problematic timing
issues of using external facilities. However, during 2003, the availability of an in-house FDM
2000 machine has greatly increased the use of RP models. This paper identifies the impact this
has had upon a) the design approach, b) the characteristics of the models produced and c) the use
of the models with user evaluation trials. Conclusions drawn show that RP has brought major
benefits but that there are some pitfalls that must be avoided.",,,,,,
"['Praniewicz, M.', 'Fox, J.C.', 'Saldana, C.']",2023-03-30T16:16:26Z,2023-03-30T16:16:26Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117700', 'http://dx.doi.org/10.26153/tsw/44579']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,The Impact of Measurement Methodology on the Diameter Measurement of Simple Additively Manufactured Features,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7b2d0484-25d4-4a55-8e0f-29061c4607b3/download,,"Dimensional qualification of additive manufacturing (AM) components is a continuing research 
problem. Different measurement techniques implemented on the same feature can yield different 
measurement results. While this can also be true for components made from more traditional 
manufacturing processes, the deviations between measurement techniques are often increased by an 
order of magnitude due to greater form and surface texture variations that occur on AM components. 
Understanding the origins of deviations and comparability of measurement processes is crucial to the 
measurement of AM components. In this work, identically designed components are produced using a 
laser powder-bed fusion process. The components are then measured using manual gaging and a 
coordinate measurement machine. The measurement of diameter is executed using various 
association criteria. A statistical analysis is performed to determine the comparability between the 
measurement techniques. Results indicate that the selection of different association criteria can provide 
statistically significant differences in the measurement result.",,,,,,
"['Gong, Haijun', 'Runzi, Michael', 'Wang, Zezheng', 'Wu, Lianjun']",2023-01-19T17:45:21Z,2023-01-19T17:45:21Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117250', 'http://dx.doi.org/10.26153/tsw/44131']",eng,2022 International Solid Freeform Fabrication Symposium,Open,3d printing,Impact of Moisture Absorption on 3D Printing Nylon Filament,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9e197366-3c07-474f-9597-88407a15f783/download,,"Nylon is a commonly used thermoplastic material featured for its high resistance to heat, 
chemical, and impact. Nylon filaments that facilitate complex part manufacturing through the 
extrusion-based 3D printing process are widely used in industry and can be easily acquired from 
various vendors or suppliers. However, as a hygroscopic material, nylon directly absorbs moisture 
from the surrounding air at a fast rate. This study concentrates on evaluating the moisture 
absorption of nylon filament in a humid environment. Experiments are conducted to correlate the 
moisture content of nylon filament with its dwelling time in a humidity chamber. Test artifacts are 
printed to demonstrate the influence of moisture on nylon part quality. Mechanical testing is also 
carried out for analyzing the material property degradation due to increased moisture content. 
Suggestions on nylon filament usage and storage are discussed.",,,,,,
"['Heinrich, Lauren', 'Fletcher, Joseph', 'Feldhausen, Thomas', 'Kurfess, Thomas', 'Saldaña, Christopher']",2023-01-27T14:05:35Z,2023-01-27T14:05:35Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117334', 'http://dx.doi.org/10.26153/tsw/44215']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Hybrid manufacturing', 'Blown-powder DED', 'Catchment efficiency']",Impact of Nozzle Condition on Powder Catchment Efficiency for Coaxial Powder Direct Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c4fd24e-22f3-4860-aeaa-27280ebaeca4/download,,"Blown powder directed energy deposition is well-designed for fine resolution additive 
manufacturing processing. Coaxial powder deposition heads use an outer layer of shielding gas 
directed by an outer nozzle to prevent oxidation occurring during the powder melting process. 
Powder blown feedstock catchment efficiency can be as low as 50-80% whereas wire deposition 
systems are closer to 98% efficient. The present study evaluates the impact of directed energy 
deposition nozzle condition on catchment efficiency. Changes in the overall outer shielding gas 
nozzle length has been found to increase material usage efficiency by 10% through convergence 
of the powder flow. The results of this experiment show that for coaxial powder deposition head 
design, if the standoff distance can safely be decreased, powder catchment efficiency can be 
increased as the outer shielding gas nozzle is increased in length, or the standoff distance is 
decreased.",,,,,,
"['Zhou, Wenchao', 'Loney, Drew', 'Fedorov, Andrei G.', 'Degertekin, F. Levent', 'Rosen, David W.']",2021-09-30T18:47:31Z,2021-09-30T18:47:31Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88276', 'http://dx.doi.org/10.26153/tsw/15217']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['ink-jet printing', 'droplet deposition', 'droplet impact behavior']",Impact Of Polyurethane Droplets on a Rigid Surface for Ink-Jet Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0fa5669f-b76f-462f-9bd8-1f1ae18fb3bc/download,University of Texas at Austin,"Ink-jet printing enables a more efficient, economic, scalable manufacturing process for a wider
variety of materials than other traditional additive techniques. Understanding droplet impact onto
a substrate is critical for accuracy control and optimization of the droplet deposition process.
This paper reviews fundamentals of droplet impact behavior from literature, followed by our
CFD simulations of droplet impact on a substrate. A numerical model is developed to simulate
the transient flow dynamics during impact and spreading of an impinging droplet on a wetting
rigid wall. The phase-field surface tracking technique is employed within a fixed (Eulerian)
structured mesh. Simulation results are critically compared and validated with predictions of
analytical models and experiments from literature. Droplet impact and spreading of a
thermoplastic polyurethane material are investigated for SFF applications.",,,,,,
"['Ramachandra, S.', 'Ravichander, B.B.', 'Farhang, B.', 'Ganesh-Ram, A.', 'Hanumantha, M.', 'Marquez, J.', 'Humphrey, G.', 'Swails, N.', 'Amerinatanzi, A.']",2021-12-06T22:45:43Z,2021-12-06T22:45:43Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90703', 'http://dx.doi.org/10.26153/tsw/17622']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'porous structures', 'mechanical properties', 'IN718', 'microstructure', 'Vickers hardness']",Impact of Porosity Type on Microstructure and Mechanical Properties in Selectively Laser Melted IN718 Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ddcc866c-c0b1-4fb9-99bf-2a5a22da52ad/download,University of Texas at Austin,"Laser Powder Bed Fusion (LPBF), one of the most employed additive manufacturing techniques
for metals, has opened new dimensions in realizing strong and weight reducing structures. In this
study, Inconel 718 (IN718) unit cell designs, were fabricated through the LPBF technique and
analyzed. Among the plethora of lattice structures in existence, BCC, BCC-Z, FCC, FCC-Z,
Gyroid, Diamond and Schwarz structures have been selected to focus on. A relationship between
the mechanical properties including yield strength, failure stress and strain, and hardness with each
type of unit cell was established. Also, the effect of the possible defects on the hardness value was
examined using microstructural analysis on samples. Scanning Electron Microscopy (SEM)
analysis was also performed to examine the possible defects and its effect on the hardness of the
as-built part. The SEM images of the grain structures indicated higher levels of isotropy in Gyroid,
and Diamond samples compared to the rest of the samples which relates to the load bearing
capacities of each unit cell structure. A similar trend was observed in terms of the uniformity of
meltpool which can be linked with the consistency in yield characteristics. Further, Diamond and
BCC-Z structures displayed high values of hardness in comparison with rest of the samples.",,,,,,
"['Khajavi, S.H.', 'Deng, G.', 'Holmström, J.', 'Puukko, P.']",2021-10-28T15:51:37Z,2021-10-28T15:51:37Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89669,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'raw material commoditization', 'supply chain']",Impact of Raw Material Commoditization on Supply Chains,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef033abb-18a7-4987-8286-60f5ebc9199e/download,University of Texas at Austin,"In this research we analyze the impact of a less cost intensive raw material supply chain
on the utilization of additive manufacturing (AM) and its implications for the whole production
supply chain. Utilizing the case data and scenario modeling we compared the competitiveness of
additive manufacturing in comparison to conventional methods such as machining and casting.
Results illustrated the increased production competitiveness with regard to both conventional
methods. Moreover, we found simplicity and swiftness of supply chain as the two significant
changes that occur as the result of a new raw material supply. One of the major limitations of this
research was due to the secrecy of the companies which are currently utilizing the technology
and their reluctance to share their perceived competitive advantage for the analysis. Therefore,
the data extracted from our own case simulations which then were analyzed to compare the
supply chains. Future research should expand the number of cases and utilize more suitable AM
machines.",,,,,,
"['Dwivedi, R.', 'Bhupathiraj, Ravi', 'Bhupathiraju, Rohit', 'Agarwal, Anvita', 'Dwivedi, Indira', 'Dwivedi, Bharat', 'Nadella, Saketh']",2021-12-01T21:55:55Z,2021-12-01T21:55:55Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90628', 'http://dx.doi.org/10.26153/tsw/17547']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['competitive robotics', 'solid freeform fabrication', 'design', 'prototyping']","Impact of Solid Freeform Fabrication in Enabling Design and Prototyping Capabilities for Competitive Robotics such as World Robotics League, FTC, FRC, WRO etc.",Conference paper,https://repositories.lib.utexas.edu//bitstreams/75f1b694-4cad-480e-9ca9-c33d8587f27e/download,University of Texas at Austin,"Competitive Robotics such as World Robotics League (WRL), World Robotics Olympiad (WRO),
BEST, FIRST programs such as FTC and FRC, etc. have recently evolved as an avenue for
learning, innovation and providing real life perspective to classroom learning. Given the short
duration for Robot Development and diverse range of challenges, innovation, and product
development has to happen at fast pace. Typical challenges include stow, configure, launch,
traverse 3D environment, sorting, assembly etc. Many challenges include underwater and aerial
spaces. Participants typically use reconfigurable “Robotics Kits”. However, ""Robotics Kits"" are
limited in many ways and do not go beyond mobile platform and simple mechanisms. Many
participants are turning to quicker alternatives such as Solid Freeform Fabrication. This paper
provides a current state of the Competitive Robotics, the existing solutions, and examples of how
Solid Freeform Fabrication is accelerating innovation in competitive robotics.",,,,,,
"['Obeidat, Suleiman', 'Nervis, Joe Jr.', 'Ma, Junkun']",2023-02-10T14:14:26Z,2023-02-10T14:14:26Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117451', 'http://dx.doi.org/10.26153/tsw/44332']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'FFF/ FDM', '316L stainless steel']",The Impact of the Printed Part Geometry on the Shrinkage and the Density of 316L Stainless Steel Parts Printed by FFF/FDM Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d43fd2e9-f43d-46b4-aa8a-54ea48a34c58/download,,,,,,,,
"['Neff, Clayton', 'Trapuzzano, Matthew', 'Crane, Nathan B.']",2021-11-01T22:09:08Z,2021-11-01T22:09:08Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89775,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['surface roughness', 'surface finish', 'strength', 'ductility', 'vapor polishing', 'ABS', '3D printing']",Impact of Vapor Polishing on Surface Roughness and Mechanical Properties for 3D Printed ABS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d06b5f3-5641-4114-afae-ed6299547bbe/download,University of Texas at Austin,"Additive manufacturing (AM) is useful when creating complex geometric models and
prototypes. However, a well-known drawback is the fact that parts produced by AM methods
typically have lower strength and higher surface roughness than traditionally-formed parts. To
compensate for this, the surface finish is commonly improved by mechanical finishing or some
type of coating. Another widely used surface treatment for ABS components is vapor polishing.
In this process, the part is exposed to a solvent vapor that partially dissolves a surface layer and
enables smoothing through surface tension-driven flow; it is known to decrease the surface
roughness. However, little work has been reported quantifying the surface roughness change or on
the mechanical impacts of this processing method. This work compares the strength, ductility and
surface finish of vapor-polished ABS tensile specimens of varying thicknesses (1 mm, 2mm, and
4 mm). Results show that elongation at break is improved, while the modulus of elasticity is
reduced in thin specimens. The tensile strength is largely unchanged. The power spectral density
for roughness features larger than 20 µm were reduced 10X.",,,,,,
"['Sperry, McKay', 'Bates, Jakob', 'Davis, Taylor', 'Nelson, Tracy W.', 'Crane, Nathan B.']",2023-01-27T14:45:13Z,2023-01-27T14:45:13Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117341', 'http://dx.doi.org/10.26153/tsw/44222']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser Powder Bed Fusion', 'Stainless Steel 316L', 'Zirconia']",Impact of Zirconia Slurry Doping on 316L Stainless Steel Prepared by Laser Powder Bed Fusion for Biological/High Corrosion Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/54f9820f-ca89-4956-a9e1-cd239c54302c/download,,"Laser Powder Bed Fusion (LPBF) is a versatile additive manufacturing (AM) method used 
primarily for processing plastics and metals. Stainless steel (type 316L) is a biocompatible metal 
used extensively for LPBF and commonly for medical applications. Zirconium Dioxide (zirconia) 
is a common engineering material used in applications ranging from dental implants to oxide 
dispersion strengthening of metals. This paper presents the process development and results of in-
situ deposition of small quantities of zirconia nanoparticles in a stainless steel (316L) powder bed 
prior to fusion in the LPBF process. The zirconia slurry was deposited as an atomized mist. The 
deposition process may be adapted to selectively dope a powder bed to form parts with spatially 
varying properties for use in complex parts. In this work, the added zirconia was shown to be 
partially distributed in the matrix, but a large portion segregated to grain boundaries and surfaces.  
Porosity increased in multi-layer parts with the zirconia agglomerated on the porous surfaces. This 
is undesirable for many applications but may be useful for creating porous surfaces for heat 
exchanger or bio-integration applications.  The deposition of zirconia limits the anisotropic crystal 
growth throughout the entire doped region.",,,,,,
"['Gong, Haijun', 'Xing, Xiaodong', 'Nel, Jan']",2021-11-18T01:16:32Z,2021-11-18T01:16:32Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90388', 'http://dx.doi.org/10.26153/tsw/17309']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['PEEK', 'impact strength', '3D printing']",Impact Strength of 3D Printed Polyether-ether-ketone (PEEK),Conference paper,https://repositories.lib.utexas.edu//bitstreams/6404e40e-78ab-4500-81e1-bec5333eb9b3/download,University of Texas at Austin,"Polyether-ether-ketone (PEEK) is a high-performance thermoplastic with high heat-, high
chemical-, high water-, and high wear-resistance. Its strength and durability also make it highly
accepted for a range of industrial applications. 3D printing of PEEK filaments offers a unique
quality and flexibility in making PEEK parts for low-volume production or special designs. This
study investigates the impact strength of 3D printed PEEK materials. The specimens are fabricated
using a fused deposition modeling (FDM) based 3D printer and tested by a pendulum impact tester
in compliance with ASTM standard. The testing result is discussed with respect to the processing
parameters and the annealing treatment. Impact strength comparison of PEEK materials
manufactured by 3D printing and by conventional production is also conducted.",,,,,,
"['Scrocco, Mackenzie', 'Chamberlain, Timothy', 'Chow, Chloe', 'Weinreber, Logan', 'Elks, Edward', 'Halford, Connor', 'Cortes, Pedro', 'Conner, Brett P.']",2021-11-10T22:22:28Z,2021-11-10T22:22:28Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90191', 'http://dx.doi.org/10.26153/tsw/17112']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['impact testing', 'kevlar', 'markforged', 'projectile']",Impact Testing of 3D Printed Kevlar-Reinforced Onyx Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8abe53c-d787-4305-9d8c-09c513eed9c0/download,University of Texas at Austin,"Kevlar is a common reinforcement used in composites for applications requiring impact
resistance. This research evaluated the impact performance of 3D printed continuously
reinforced Kevlar fiber on 3D printed nylon composites containing chopped carbon fiber (CCF).
The 3D printer used was a Markforged Mark Two material extrusion system, and Onyx is the
trade name of Markforged’s nylon/CCF material. In this work, a diverse number of composite
architecture designs including type of infill pattern, number of Kevlar layers, and location of
Kevlar layers were investigated. The printed specimens were characterized using a Charpy
impact testing and gas gun ballistic testing. Results were compared on the basis of weight and
estimated part cost.",,,,,,
"['Wasser, Tobias', 'Jayal, Anshu Dhar', 'Pistor, Christoph']",2019-03-11T16:33:42Z,2019-03-11T16:33:42Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73580', 'http://dx.doi.org/10.26153/tsw/722']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'Construction Procedures']",Implementation and Evaluation of Novel Buildstyles in Fused Deposition Modeling (FDM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/0c571c76-5ee2-46cf-8ff5-cee452bf2392/download,,"Previous investigations have shown that the optimization of extrusion dynamics in .conjunction with the buildstyle pattern is of paramount importance to increase part quality in
Fused Deposition Modeling (FDM). Recently domain decomposition and space filling
curves have been introduced for slice generation in FDM [1]. The current work focuses
on the implementations of fractal-like buildstyle .patterns using. Simulated Annealing [2,
3], Lin-Kernighan algorithms [4] and Construction Procedures based on Nearest
Neighbor Heuristics [5]. These computational optimization procedures are able to
generate filling patterns that allow the continuous deposition of a single road to fill arbitrary shaped domains. The necessary software modules to produce arbitrary threedimensional artifacts have been developed and are evaluated with respect to part quality
and build time.",,,,,,
"Silwal, B.",2021-11-16T15:42:13Z,2021-11-16T15:42:13Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90318', 'http://dx.doi.org/10.26153/tsw/17239']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['material processing', 'hands-on', '3D printer', 'engineering course', 'engineering education']",Implementation of 3D Printer in the Hands-On Material Processing Course: An Educational Paper,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aafd3f6d-d836-4f3d-b215-b14336ddbcb3/download,University of Texas at Austin,"Manufacturing equipment and technology will continue to be an integral part of engineering education. Using
advanced and modern equipment and technology not only emphasizes hands-on activity-based teaching and
learning, but it also makes the educator and the program competitive. There are many advantages to implementing
3-d printers in engineering education; however, there are also some challenges. In this paper, a two-year
implementation of 3-d printers in a traditional material processing undergraduate engineering course has been
presented and discussed.",,,,,,
"['Pratap, Aparajit', 'Crawford, Richard H.']",2019-11-20T15:56:40Z,2019-11-20T15:56:40Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78463', 'http://dx.doi.org/10.26153/tsw/5548']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Material Modeling,Implementation of a Functionally Gradient Material Modeling and Design System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa34ffad-2701-414a-a788-9d8017fa7ed8/download,,"New advancements in Solid Freeform Fabrication (SFF) processes promise the capability
to produce Functionally Gradient Material (FGM) parts, in which the material compositions vary
spatially. To realize this potential there is a need for CAD methods and design software to
model, design, represent and exchange material information and instructions to the
manufacturing process. However, currently available commercial CAD systems are limited to
representing and storing only geometric information, which is not adequate for material design
purposes. This work presents an extension of a theoretical approach based on Volumetric MultiTexturing (VMT) and hypertexturing schemes to make the material design process intuitive and
user controllable. Inverse distance weighted interpolation is used in conjunction with procedural
material functions to accomplish axial or linear material gradient directions from surface to
surface across a solid. This offers the capability of specifying fixed material composition values
to the faces in the solid and blending them across the interior of the solid. The extension of the
proposed approach to the modeling of discrete material domains is also discussed. These material
regions can be combined using special sets of operators depending on the form of the material
functions. Finally, a design environment has been developed, which allows users to
systematically apply material information to geometry and captures design intent.",,,,,,
"['Ito, Fumio', 'Niino, Toshiki']",2021-11-01T21:42:30Z,2021-11-01T21:42:30Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89764,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['poly phenylene sulfide', 'low temperature', 'tophat profile laser', 'laser sintering']",Implementation of Tophat Profile Laser into Low Temperature of Poly Phenylene Sulfide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc29a658-e184-4cd7-9075-f0140e35bf04/download,University of Texas at Austin,"Poly Phenylene Sulfide is a high performance plastics that is used in high-value parts. The
most commercially available plastic laser sintering machines employ Gaussian profile CO2 laser.
In this research, low temperature process of the material with tophat profile laser is tested. By
using tophat profile, a tensile strength of 64.5 MPa was obtained. The value is equivalent to 75%
of those from injection molding and 140% of standard laser sintered polyamide. Tophat profile
effectively suppressed sparkling and fuming and improved surface finish decreasing surplus
sintering or sticking powder.",,,,,,
"Frank, Matthew C.",2020-03-09T13:51:46Z,2020-03-09T13:51:46Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80179', 'http://dx.doi.org/10.26153/tsw/7198']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Rapid Prototyping,Implementing Rapid Prototyping Using CNC Machining (CNC-RP) Through a CAD/CAM Interface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8f5ea8c0-dc7e-4f62-94a3-4a8b3a5096db/download,,"This paper presents the methodology and implementation of a rapid machining system using a
CAD/CAM interface. Rapid Prototyping using CNC Machining (CNC-RP) is a method that has
been developed which enables automatic generation of process plans for a machined component.
The challenge with CNC-RP is not the technical problems of material removal, but with all of
the required setup, fixture and toolpath planning, which has previously required a skilled
machinist. Through the use of advanced geometric algorithms, we have implemented an
interface with a CAD/CAM system that allows true automatic NC code generation directly from
a CAD model with no human interaction; a capability necessary for a practical rapid prototyping
system.",,,,,,
"['Adams, D.W.', 'Turner, C.J.']",2021-11-02T20:14:52Z,2021-11-02T20:14:52Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89885,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['implicit slicing method', 'infill pattern', 'GCode', 'fused deposition modeling']",Implicit Slicing Method for Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/37b860f2-8bd6-41ed-837a-c8c4443a4e50/download,University of Texas at Austin,"All additive manufacturing processes involve a distinct preprocessing stage in which a set
of instructions, or GCode, that control the process specific manufacturing tool are generated,
otherwise known as slicing. In regards to fused deposition modeling, the GCode defines many
crucial parameters which are needed to produce a part, including tool path, infill density, layer
height, feed rate, tool head and plate temperature. The majority of current commercial slicing
programs generate tool paths explicitly, and do not consider particular geometric properties of
parts, such as thin walls, small corners and round profiles that can result in critical voids leading
to part failure. This work replicates an implicit slicing algorithm in which functionally derived
infill patterns are overlaid onto each layer of a part, reducing the possibility of undesired voids and
flaws. This work also further investigates the effects that varying implicitly derived infill patterns
have on a part’s mechanical properties through tensile testing dog bone specimens with three
different infill patterns and comparing ultimate stress and elastic modulus properties.",,,,,,
"['Deckard, Carl', 'Miller, David']",2018-10-05T18:30:41Z,2018-10-05T18:30:41Z,1995,Mechanical Engineering,doi:10.15781/T26W96V1G,http://hdl.handle.net/2152/68722,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'SFF', 'CAD']",Improved Energy Delivery For Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/489cdc5e-801b-4982-8d3f-45da71ae25e6/download,,"Selective Laser Sintering (SLS) is a leadingtechnology in the important new area of Solid
Freeform Fabrication (also ca1ledR.apid Prototyping). Selective Laser Sintering produces freeform
parts directly from a CAD model by building the parts up in layers from a powder. A laser is used
to selectively melt each layer of powder to form the part. The laser beam is scanned across the
powder using two galvanometer scanners. The energy delivery system (laser, optics, scanner and
controls) is a critical component technology of SLS. Projects with the objective of improving the
energy delivery system are underway at Clemson University",,,,,,
"['Martina, Filomeno', 'Williams, Stewart W.', 'Colegrove, Paul']",2021-10-11T20:44:49Z,2021-10-11T20:44:49Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88640', 'http://dx.doi.org/10.26153/tsw/15574']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Ti-6Al-4V', 'interpass rolling', 'microstructure', 'distortion', 'residual stress', 'ansiotropy']",Improved Microstructure and Increased Mechanical Properties of Additive Manufacture Produced Ti-6Al-4V By Interpass Cold Rolling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6069348b-a63d-4fae-b51f-f6211b000329/download,University of Texas at Austin,"Distortion, residual stress and mechanical property anisotropy are current challenges in additive manufacturing (AM) of Ti–6Al–4V. High-pressure, interpass rolling was applied to linear
AM parts and resulted in a change from large columnar prior β grains to a completely equiaxed
microstructure with grains as small as 89 µm. Moreover, α laths thickness was also reduced to
0.62 µm. The change in material microstructure resulted in a substantial improvement of all mechanical properties tested, which were also totally isotropic. In rolled specimens, maximum measured strength and elongation were 1078 MPa and 14% respectively, both superior to the wrought material. Distortion was reduced to less than half. Rolling proved to be a relatively easy method to overcome some of the critical issues which keep AM from full industrial implementation.",,,,,,
"['Cohen, Daniel L.', 'Tsavaris, Andrew M.', 'Lo, Winifred M.', 'Bonassar, Lawrence J.', 'Lipson, Hod']",2021-09-28T17:53:19Z,2021-09-28T17:53:19Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88137', 'http://dx.doi.org/10.26153/tsw/15078']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['alginate hydrogels', 'Solid Freeform Fabrication', 'cell-seeded tissue engineering scaffolds']",Improved Quality of 3D-Printed Tissue Constructs Through Enhanced Mixing of Alginate Hydrogels,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f74acc54-df40-4480-8199-1c1f46bd3c11/download,University of Texas at Austin,"While alginate hydrogel is a desirable material platform for Solid Freeform Fabrication (SFF) of 
cell-seeded tissue engineering scaffolds, achieving consistently high-quality results can be 
challenging. Local variations in the material properties cause inconsistent material deposition 
behavior and consequently decrease the resultant geometric fidelity of the construct. The effects 
of gel mixing on material property consistency, geometric fidelity, and cell viability were 
characterized in an attempt to improve the formulation’s compatibility with SFF processing. 
Material homogeneity was quantified through a novel experimental setup composed of an 
EnduraTEC mechanical test-frame and custom syringe-extrusion jig. Cell viability and 
geometric fidelity were assessed using standard protocol. The baseline mechanical stiffness of 
the printed samples was 16±3 kPa (n=6). We found that increasing mixing reduced material 
inconsistency and improved geometric fidelity, without adversely affecting cell viability: the 
printed construct quality was drastically improved by increasing mixing well beyond previously 
established limits.",,,,,,
"['Emami, Mohammad Mahdi', 'Rosen, David W.']",2021-11-15T21:12:52Z,2021-11-15T21:12:52Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90274', 'http://dx.doi.org/10.26153/tsw/17195']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['photopolymerization', 'photobleaching', 'grayscale stereolithography', 'volumetric intensity']",An Improved Vat Photopolymerization Cure Model Demonstrates Photobleaching Effects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9da46d83-a04d-4e1d-a079-200b4758189b/download,University of Texas at Austin,"An improved high-fidelity simulation model for a grayscale projection micro-stereolithography
process has been developed. The modeling purpose is to accurately predict cured part shapes and
dimensions, given a radiation intensity distribution. The model employs COMSOL to solve a series
of chemical reaction differential equations that model the evolution of chemical species
(photoinitiator, monomer, and polymer) concentrations. Additionally, the model incorporates the
effects of oxygen inhibition and species diffusion. This research offers two primary contributions
to the cure model: the consideration of volumetric intensity to model variations in photoinitiator
absorbance as a function of depth into the resin and a change to the rate model for photoinitiator
to free radical conversion. The effects of these changes demonstrate observed photobleaching
effects. Simulated cured part profiles are compared to experiments and demonstrate good
agreement. Additionally, initial results are presented on the usage of the simulation model in a new
process planning method.",,,,,,
"['Niino, Toshiki', 'Morita, Keisuke']",2021-09-30T13:48:21Z,2021-09-30T13:48:21Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88251', 'http://dx.doi.org/10.26153/tsw/15192']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['plastic laser sintering', 'additive manufacturing', 'spot sized CO2 laser beams', 'micro-plastic-laser-sintering', 'fine geometries', 'complex geometries']",Improvement in Geometrical Resolution of Plastic Laser Sintering by using Reduced Spot Sized Laser,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1f5fe2ab-8b0b-4ff9-9452-b65743a78234/download,University of Texas at Austin,"Plastic laser sintering is one of the most promising processes for rapid manufacturing
among various additive manufacturing (AM) technologies. Though the process tends to
be applied to fabrication of larger parts in comparison to stereolithography, its ability of
creating complex structure as an advantage of additive manufacturing technologies
should be demonstrated in production of smaller parts and parts including fine and
complex geometries as well. In this research, narrow CO2 laser beams with spot
diameters of 130µm and 150µm were tested while the commercially available machines
are equipped with those around 500µm. Relationship between resolution (available wall
thickness) and spot diameter is proportional when the diameter is greater than 150µm,
but effect of reducing the spot size further is not significant. The minimum wall
thickness of 180µm was obtained, but this part was so fragile that skill in breakout
treatment is critical. To discuss the mechanical strength of micro-plastic-laser-sintering,
packing rate of obtained parts was introduced as an index of the strength. Build
parameter that minimizes the wall thickness without decreasing the tensile strength
below 30MPa was searched, and a set of parameters that provides minimal thickness of
0.6mm was obtained. Reducing laser spot size inevitably leads to shrinkage of scanning
range of galvanometer mirrors. To overcome this problem, the whole laser scanning
system was set on an X-Y positioner which are driven by stepper motors. The whole
exposure area is divided into some regions each of which is smaller than range of
galvanometer mirror system, and it is exposed by repeating fast scanning by
galvanometer mirrors and slow sliding by the X-Y positioner. Problems occurring at the
region boundary were investigated. As counter measures, overlapping of exposure areas
and switching of region boundary are introduced and successfully eliminate the
problem.",,,,,,
"['Chen, Ssuwei', 'Bourell, David L.', 'Wood, Kristin L.']",2020-02-24T15:26:22Z,2020-02-24T15:26:22Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80082', 'http://dx.doi.org/10.26153/tsw/7103']",eng,2005 International Solid Freeform Fabrication Symposium,Open,proton exchange membrane,Improvement of Electrical Conductivity of SLS PEM Fuel Cell Bipolar Plates,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb6acb34-1e6e-47a3-8345-5774df03de88/download,,"Previous work in this research demonstrated the feasibility of fabrication of proton
exchange membrane (PEM) fuel cell bipolar plates by an indirect selective laser sintering
(SLS) route. Properties of the SLS bipolar plate, such as flexural strength, corrosion
resistance and gas impermeability, etc. are quite promising and satisfactory. However,
initial results showed that there was still room for the improvement in electrical
conductivity. This paper summaries the strategies investigated in an effort to increase the
electrical conductivity, among which are: (1) infiltration of brown parts with conductive
polymer (2) addition of a liquid phenolic infiltration/re-curing step prior to final sealing
and (3) reduction of glassy carbon resistivity by curing process parameter control. Results
show that the electrical conductivity value may be improved from 80 S/cm to around 108
S/cm, which is equivalent to a 35% jump, when the phenolic infiltration/re-curing step is
applied before final epoxy sealing.",,,,,,
"['Kigure, T.', 'Niino, T.']",2021-11-02T18:32:08Z,2021-11-02T18:32:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89862,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['recycle rate', 'low temperature', 'processing', 'laser sintering']",Improvement of Recycle Rate in Laser Sintering by Low Temperature Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/00f44607-95f9-43bf-846a-139e555173e9/download,University of Texas at Austin,"Laser sintering process selectively solidifies its powder bed to obtain designated parts and leaves the rest
unsolidified. When the remained powder is recycled, a certain amount of fresh powder is added to moderate the
effect of deterioration by preheating in the previous batch. In terms of economy, improvement of the recycle rate
of used powder is one of the big challenges. The authors are developing a novel laser sintering process that
prevents part being processed from warping not by preheating the powder bed but by anchoring the parts to a
rigid base plate. Since the new process, namely low temperature process, can lower the bed temperature than
normal high temperature process, it is expected to reduce deterioration of the used powder. In present research,
processablity of recycled powder is evaluated by its MFR, and it is shown that operation at a high recycle rate
more than 90% is possible.",,,,,,
"['Nelson, Christian', 'McAlea, Kevin', 'Gray, Damien']",2018-10-10T15:29:47Z,2018-10-10T15:29:47Z,1995,Mechanical Engineering,doi:10.15781/T2222RR22,http://hdl.handle.net/2152/68754,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'material shrinkage', 'laser beam']",Improvements in SLS Part Accuracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6297e24b-7f12-437b-9c3b-f958da9ea5c8/download,,"SLS® part accuracy is influenced by a number ofmachine and material characteristics. Some of
the most significant sources of error are associated with laser beam positioning (static and
dynamic) on the part bed surface and uncertainty in the calibration factors used to compensate
for material shrinkage and growth as well as the finite width ofthe laser beam. Another source of
error is the minimum resolution of the process, which is a dependent on the particle size and
shape ofthe material. In this presentation, technical background on these issues will be provided.
In addition, part data obtained with a number of SLS materials demonstrating improved accuracy
obtained through machine modifications and improved calibration methods will be described.",,,,,,
"['Crane, N. B.', 'Wilkes, J.', 'Sachs, E.', 'Allen, S. M.']",2020-02-21T15:28:32Z,2020-02-21T15:28:32Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80063', 'http://dx.doi.org/10.26153/tsw/7085']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Solid freeform fabrication,Improving Accuracy of Powder Sintering-based SFF Processes by Metal Deposition from Nanoparticle Dispersion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ad1dadf-d16e-4971-8c49-e733f4579364/download,,"Solid Freeform Fabrication processes such as three-dimensional printing (3DP) and selective
laser sintering (SLS) produce porous parts that must be densified. New steel infiltration methods
can produce parts of standard alloy compositions with properties comparable to wrought
materials. However, the infiltration process introduces dimensional errors due to both shrinkage
and creep—particularly at the high temperatures required for steel infiltration. A post-processing
method has been developed to reduce creep and shrinkage of porous metal skeletons. Tests have
achieved over 90% reduction in creep and 50% reduction in shrinkage. In this method, metal is
deposited into the porous part from a suspension of metallic nanoparticles. These particles
densify at low temperatures to reinforce the bonds and reduce stress concentrations that amplify
creep deformation in untreated parts. After treatment, the reinforced parts can be densified by
infiltration.",,,,,,
"['Vetterli, M.', 'Schmid, R.', 'Schmid, M.', 'Harke, S.', 'Durand, T.', 'Wegener, K.']",2021-10-21T21:08:22Z,2021-10-21T21:08:22Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89449,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'energy efficiency', 'energy consumption', 'climate control', 'air-conditioning', 'passenger cars']",Improving Energy Efficiency of Car Climate Control with SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a3361936-2ef6-4b90-8b79-9475308503d8/download,University of Texas at Austin,"In Europe, passenger cars are responsible for 12% of CO2 emissions. The European
Commission established new regulations to drastically reduce the emissions from 130g to 95g
CO2 per km between 2015 and 2021. While the automobile industry is looking at different ways
to meet those criteria, the presented industry-driven project aims at reducing energy consumption
by up to 30% of air-conditioning (AC) in passenger cars with the introduction of a novel system.
The current systems reduce the fuel economy to up to 20% for gas motors and even more for
electric cars. Through Selective Laser Sintering (SLS) design freedom and short production
cycles; the design of the AC casing was drastically optimized to increase its contact area with
incoming air. To further increase the heat exchange throughout the system, the thermal
conductivity of SLS material was improved by incorporation of mineral fillers. The successful
implementation of both optimizations led to a CO2 emission reduction of around 50% for the
climate control of passenger cars.",,,,,,
"['Ram, G. D. Janaki', 'Yang, Y.', 'George, J.', 'Robinson, C.', 'Stucker, B. E.']",2020-03-05T19:57:38Z,2020-03-05T19:57:38Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80152', 'http://dx.doi.org/10.26153/tsw/7173']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic Consolidation,Improving Linear Weld Density in Ultrasonically Consolidated Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/720f9191-d5de-4029-ad79-f5ea934587af/download,,"Ultrasonic consolidation is a novel additive manufacturing process with immense
potential for fabrication of complex shaped three-dimensional metallic objects from metal foils.
The proportion of bonded area to unbonded area along the layer interface, termed linear weld
density (LWD), is perhaps the most important quality attribute of ultrasonically consolidated
parts. Part mechanical properties largely depend on LWD and a high level of LWD must be
ensured in parts intended for load-bearing structural applications. It is therefore necessary to
understand what factors influence LWD or defect formation and devise methods to enhance bond
formation during ultrasonic consolidation. The current work examines these issues and proposes
strategies to ensure near 100% LWD in ultrasonically consolidated aluminum alloy 3003 parts.
The work elucidates the effects of various process parameters on LWD and a qualitative
understanding of the effects of process parameters on bond formation during ultrasonic
consolidation is presented. The beneficial effects of using elevated substrate temperatures and its
implications on overall manufacturing flexibility are discussed. A preliminary understanding of
defect morphologies and defect formation is presented, based on which a method (involving
surface machining) for minimizing defect incidence during ultrasonic consolidation is proposed
and demonstrated. Finally, trade-offs between part quality and build time are discussed.",,,,,,
"['Shojib Hossain, Mohammad', 'Ramos, Jorge', 'Espalin, David', 'Perez, Mireya', 'Wicker, Ryan']",2021-10-07T19:01:06Z,2021-10-07T19:01:06Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88505', 'http://dx.doi.org/10.26153/tsw/15439']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['FDM-manufactured parts', 'tensile mechanical properties', 'processing parameters', 'Insight']",Improving Tensile Mechanical Properties of FDM-Manufactured Specimens via Modifying Build Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0cfb10ff-e7ba-47bc-842c-007a1e2841b9/download,University of Texas at Austin,"In this paper, the focus was on improving tensile mechanical properties of FDMmanufactured parts by adjusting FDM processing parameters and analyzing stress concentration
features between adjacent roads of material. FDM processing parameters are specified by the
user via Insight – the file preparation software for most FDM machines. Even though Insight
gives the impression that adjacent roads are to be deposited and connected throughout, an optical
imaging observation of the deposited material revealed that adjacent roads are not consistently
connected forming voids that reduce mechanical performance. Therefore, this work reports the
tensile mechanical properties of specimens built using three sets of parameters: standard/default
parameters, an Insight revision method, and a visual feedback method. When compared to the
default build parameters, the experimentally determined, visual feedback approach produced
specimens, in some cases, exhibiting as high as 19% improvement in ultimate tensile strength.",,,,,,
"['Fisher, Joseph W.', 'Miller, Simon W.', 'Bartolai, Joseph', 'Simpson, Timothy W.']",2024-03-27T15:44:08Z,2024-03-27T15:44:08Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124487', 'https://doi.org/10.26153/tsw/51095']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'triply periodic minimal surface', 'shape optimization']",Improving the Mechanical Response of the IWP Exo-skeletal Lattice Through Shape Optimization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dd9b91ff-c95c-48b3-8b7d-5b1cf6f0c5e1/download,University of Texas at Austin,"Triply Periodic Minimal Surfaces have been identified as good candidates for the generation of
lattice structures produced with additive manufacturing. These TPMS-based lattice structures
avoid sharp features that are characteristic of strut-based lattice structures because of their
constant zero mean curvature. Although studies have explored part-scale optimization using
TPMS-based lattice structures, they have only varied the volume fraction by changing the level
set in the approximate surface equations. By defining new parameterizations in the approximate surface equation, we can redistribute volume within the lattice structure at any volume
fraction. In this paper, we introduce an approach for optimization of this new parameterization
of TPMS equations using the Borg multi-objective evolutionary algorithm. We demonstrate
this framework on the IWP exo-skeletal lattice under uniaxial compression. A relationship
between the new parameters and the level set is derived for designs on the Pareto frontier of
the optimized IWP TPxS. The performance of the Pareto optimal designs and the efficacy of
the optimization approach are shown by comparing to the standard IWP lattice and four other
lattices that share the same topology. The optimized designs are implemented and shared in
custom nTopology blocks.",,,,,,
"['Jayanthi, Suresh', 'Hokuf, Bronson', 'Lawton, John']",2018-11-14T20:28:13Z,2018-11-14T20:28:13Z,1996,Mechanical Engineering,doi:10.15781/T2HT2GX71,http://hdl.handle.net/2152/70262,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['stereolithographic', 'photopolymers', 'prototyping techniques']",Improving the Thermal Stability of Somos™ 6110 Photopolymer Patterns,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f9c22c09-cc2f-48c5-924b-3fe5f1e4188f/download,,"With the increased emphasis on functional testing and tooling applications
using stereolithographic rapid prototyping (RP) techniques, the need for RP
materials with improved thermal stability is becoming more pronounced. Glass
transition temperature and Heat deflection temperature are two commonly used
measures to determine the thermal stability of a polymeric material.
This paper shows the effect of different postcuring techniques on the heat
deflection temperature (HDT) of DuPont Somos™ 6110 photopolymer. In addition,
the benefits of using heat transfer mediums which provide neutral buoyancy and
thus minimize thermal distortions are discussed.",,,,,,
"['Malyala, Santosh Kumar', 'Manmadhachary, A.', 'Kumar, Yennam Ravi']",2021-10-21T15:45:20Z,2021-10-21T15:45:20Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89401,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'volumetric accuracy', 'octree structure', 'STL file', 'adaptive slicing']",Improving Volumetric Accuracy of AM Part Using Adaptive Slicing of Octree Based Structure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1bdd98db-fb97-46d9-ab68-7663508c321b/download,University of Texas at Austin,"In Additive Manufacturing (AM) processes, the layer-by-layer fabrication of complex
geometries may lead to stair casing and thus error resulting in volumetric inaccuracies in the
model. Using thinner slices reduces the staircase error and improves part accuracy but there is a
tradeoff between number of layers and the build time for manufacturing part. This paper
presents a octree based structure to improve the accuracy as well as reduces the build time. In the
current work, firstly converting STL file into a modified boundary octree data structure
(MBODS) and then calculating the non-uniform slice thicknesses (adaptive slicing) from the
octree representation. This slice thickness at any height is computed from the AM machine
parameters and the smallest octree size at that available height. After the computation of the
variable slice thicknesses has been completed, the part is virtually manufactured and the part
errors are calculated. The virtually manufactured part and physical models are inspected to
evaluate the volumetric errors. This algorithm uses an octree approach to improve the volumetric
accuracy. And build time for the two different case studies are also done.",,,,,,
"['Alberts, D.', 'Schwarze, D.', 'Witt, G.']",2021-11-04T13:45:37Z,2021-11-04T13:45:37Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89958,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['in situ', 'real time', 'melt pool monitoring', 'selective laser melting', 'part density', 'Inconel 718']",In Situ Melt Pool Monitoring and the Correlation to Part Density of Inconel® 718 for Quality Assurance in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f92f4ca0-63f8-49cd-9a3c-20c2bc5dcaba/download,University of Texas at Austin,"Additive Manufacturing looks back on a history of about two decades and today SLM® technology
keeps moving as an integral element in industrial production environments. Sensitive markets such as energy,
medical or aerospace have the highest quality standards for complex, safety-related and highly stressed
components which are to be met at competitive costs for each build job and single part. In this context process
monitoring is necessary for documentation, qualification and at the same time it is expected to be able to detect
process anomalies during the process. In addition to surface roughness, part density which mostly depends on
volume energy, changing with laser power, scan velocity etc., is a distinctive quality feature of every
component. This paper presents a method for a real time melt pool monitoring system based on photodiodes
and the correlation between thermal emission and part density of Inconel® 718 with respect to volume energy
deviation.",,,,,,
"['Liu, W.', 'Sun, W.']",2021-10-21T20:51:02Z,2021-10-21T20:51:02Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89444,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['solid freeform fabrication', 'in situ printing']",In Situ Printing - An Alternative Three Dimensional Laden Structure Fabrication Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be476475-d15a-4b6a-815f-862f5afd55f1/download,University of Texas at Austin,"Recapitulating a structure that mimics the anatomic geometries and intratissue cell
distribution as in live organism is a major challenge of tissue engineering nowadays. Solid freeform fabrication (SFF) has been demonstrated as an efficient tool for this purpose. In this paper
we presented a SFF based in situ printing method that is free of fabrication time frame and
fabrication environment constrains. The fabrication parameters on strut formability, fabricated
structural stability against gentle fluidic disturbance, and the integrity of the fabricated structure
in cell culture environment were studied to assess the potential of the fabrication method on
biomedical application. Based on the results, controlled strut formability can be achieved in an
appropriate cross-linking deposition range. Alginate composition is the main parameter that
dominates the stability and integrity of the fabricated structure. A parameter set that can produce
a stable scaffold with the ability to maintain its structure in cell culture environment for at least
15 days was optimized.",,,,,,
"['Kolan, Krishna C.R.', 'Thomas, Albin', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2021-10-18T21:13:43Z,2021-10-18T21:13:43Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89246,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['pore geometry', 'bioactive glass scaffolds', 'laser sintering', 'bone repair', 'bone replacement']",In Vitro Assessment of Laser Sintered Bioactive Glass Scaffolds with Different Pore Geometries,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a513389-d831-4870-887d-17f38ebbfa11/download,University of Texas at Austin,"The pore geometry of bioactive glass scaffolds intended for use in bone repair or
replacement is one of the most important parameters that could determine the rate of bone
regeneration. The pore geometry would also affect the mechanical properties of the scaffolds and
their rate of degradation. Scaffolds with five different architectures, having ~50% porosity, were
fabricated with silicate (13–93) and borate (13–93B3) based bioactive glasses using a laser
sintering process. An established, late-osteoblasts/early-osteocytes cell line was used to perform
cell proliferation tests on the scaffolds. The results indicated that the cells proliferate
significantly more on the scaffolds which mimic the trabecular bone architecture compared to
traditional lattice structures.",,,,,,
"['Conway, K.M.', 'Kulkarni, S.S.', 'Smith, B.A.', 'Pataky, G.J.', 'Mocko, G.M.', 'Summers, J.D.']",2021-11-30T21:53:23Z,2021-11-30T21:53:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90562', 'http://dx.doi.org/10.26153/tsw/17481']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['shear strength', 'shear deformation', 'grips', 'cellular materials', 'in-plane']",In-Plane Pure Shear Deformation of Cellular Materials with Novel Grip Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb6fdd5b-ae62-4394-ad20-8c35aa36dd2d/download,University of Texas at Austin,"Cellular materials are popular due to their high specific strength, but their in-plane shear
behavior is not well understood. Current experimental methods are limited due to the lack of pure
shear loading as common arcan-style grips have not been adjusted for cellular materials. A
significant concern is a mixture of shear loading with grip induced tension. While in bulk materials
the tensile force can be assumed negligible, it has a significant impact on the deformation behavior
of cellular materials. In this study, finite element modeling simulations were used to demonstrate
that using a new sliding grip design reduced grip induced tension on cellular materials.
Experimental studies were performed on honeycomb cellular materials with traditional and newlydeveloped grips to calculate and compare the shear strength and ductility of honeycomb cellular
materials. The study concluded that traditional grips overestimate the shear strength of honeycomb
cellular materials and honeycomb cellular materials in pure shear with limited grip induced tension
has significantly lower strength and ductility due to the early formation of plastic hinges.",,,,,,
"['Montazeri, Mohammad', 'Rao, Prahalada']",2021-11-03T21:50:25Z,2021-11-03T21:50:25Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89943,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'LPBF', 'heterogeneous sensing', 'in-situ monitoring', 'meltpool thermal imaging', 'high-speed imaging', 'photodetection', 'spectral graph theory', 'manifold learning', 'laplacian eigenvectors']",In-Process Condition Monitoring in Laser Powder Bed Fusion (LPBF),Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3483fbb-f83e-401d-82d9-8812427f198e/download,University of Texas at Austin,"The goal of this work is to monitor the laser powder bed fusion (LPBF) process using an array
of heterogeneous sensors. This goal is termed as build status monitoring. The overarching aim is
to usher a qualify-as-you-build quality assurance paradigm in LPBF whereby incipient build
defects are detected through analysis of data acquired from in-process sensors. This will allow
opportune preventive action to avert propagation of build defects across multiple layers. In pursuit
of this goal, a commercial LPBF machine at the National Institute of Standards and Technology
(NIST) was integrated with three types of sensors, namely, a photodetector, high-speed video
camera, and SWIR thermal camera with the following objective: to develop and apply a spectral
graph theoretic approach to monitor the LPBF build status from the data acquired by the three
sensors. This objective will lead to early identification of incipient defects that afflict LPBF despite
extensive process automation. The proposed approach is illustrated with experimental sensor data
acquired during LPBF of a part having a steep overhang feature of ~ 40.5o
. Parts with such steep
overhang features may exacerbate deleterious consequences such as poor surface finish, porosity,
and distortion. Hence, close monitoring of the signal patterns during scanning of overhang areas
is consequential for early detection of build defects. The proposed approach detected differences
between overhang and non-overhang build status for different sensors with the statistical fidelity
(F-score) of 95% from thermal camera signatures to 79% with the photodetector. In comparison,
conventional signal analysis techniques - e.g., neural networks, support vector machines, linear
discriminant analysis, etc., are evaluated with F-score in the range of 40% to 60%. As part of our
forthcoming work, this study will be further expanded to include more build defects, e.g., due to
material contamination.",,,,,,
"['Jamshidinia, M.', 'Boulware, P.', 'Marchal, J.', 'Mendoza, H.', 'Cronley, L.', 'Kelly, S.', 'Newhouse, S.']",2021-10-28T19:40:52Z,2021-10-28T19:40:52Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89680,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['cross contamination', 'in-process monitoring', 'spectrometer', 'photodetector', 'laser powder bed fusion (L-PBF)']",In-Process Monitoring of Cross Contamination in Laser Powder Bed Fusion (L-PBF) Additive Manufacturing (AM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/b65f1a5a-1aeb-4f8f-b1d7-342b3b53ea7c/download,University of Texas at Austin,"Cross contamination in laser powder bed fusion (L-PBF) Additive Manufacturing (AM)
could locally change the chemical composition and stress distribution in a component. It also
could result in the formation of flaws, and consequently lower the mechanical performance of a
component. In this study, the in-process monitoring and detection of cross contamination was
investigated in L-PBF process, also known as direct metal laser sintering (DMLS). A setup was
designed and fabricated at EWI, where contaminant materials could be introduced on the powder
bed without interrupting the fabrication process or breaking the chamber environment. Tungsten
particles were used as the contaminant material, in the matrix of Inconel 625. Six levels of
contamination were calibrated, and were introduced in two static and dynamic modes.
Photodetector, spectrometer, and optical camera were used for the data acquisition. One of the
sensors showed the most promising results. X-ray computed tomography (CT) and optical
microscopy were used to validate data collected by the sensors.",,,,,,
"['Mischliwski, Stefan', 'Weigold, Matthias']",2021-11-18T19:07:28Z,2021-11-18T19:07:28Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90471', 'http://dx.doi.org/10.26153/tsw/17392']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['pasty ceramic composite', 'ceramics', 'UV-curing', 'in-process', 'extrusion-based additive manufacturing', 'additive manufacturing']",In-Process UV-Curing of Pasty Ceramic Composite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/05a15cbe-43df-4da0-bf46-15dafe63f884/download,University of Texas at Austin,"Within recent years,a wide range of additive manufacturing processes have been developed.
While powder bed based fusion processes like selective laser melting and melting processes like
fused layer modelling are being increasingly used in industrial applications, prototyping other
processes are in the initial stage. This paper develops a new method for an extrusion-based process
of pasty UV-curing ceramic composite material. The method proposes an approach to continuously
cure the material while it is deployed to reduce process time and generate complete cured parts. A
milling machine has been modified with a syringe and a UV-light source to accommodate the
process. Experimental studies have been carried out to examine the influence of the process
parameters on the curing process. As a result, a parameter set has been found to make fully dense
and cured ceramic composite parts.",,,,,,
"['Breese, P.P.', 'Becker, T.', 'Oster, S.', 'Metz, C.', 'Altenburg, S.J.']",2024-03-27T15:45:53Z,2024-03-27T15:45:53Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124488', 'https://doi.org/10.26153/tsw/51096']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['laser thermography', 'defect detection', 'laser powder bed fusion', 'in-situ', 'additive manufacturing']",IN-SITU DEFECT DETECTION FOR LASER POWDER BED FUSION WITH ACTIVE LASER THERMOGRAPHY,Conference paper,https://repositories.lib.utexas.edu//bitstreams/28193a5f-e96a-4da0-b9e2-3ce5d8a79fa7/download,University of Texas at Austin,"Defects are still common in metal components built with Additive Manufacturing (AM). Process
monitoring methods for laser powder bed fusion (PBF-LB/M) are used in industry, but
relationships between monitoring data and defect formation are not fully understood yet.
Additionally, defects and deformations may develop with a time delay to the laser energy input.
Thus, currently, the component quality is only determinable after the finished process.
Here, active laser thermography, a nondestructive testing method, is adapted to PBF-LB/M,
using the defocused process laser as heat source. The testing can be performed layer by layer
throughout the manufacturing process. We study our proposed testing method along experiments
carried out on a custom research PBF-LB/M machine using infrared (IR) cameras.
Our work enables a shift from post-process testing of components towards in-situ testing during
the AM process. The actual component quality is evaluated in the process chamber and defects can
be detected between layers.",,,,,,
"['Sturm, Logan', 'Albakri, Mohammed', 'Williams, Christopher B.', 'Tarazaga, Pablo']",2021-10-28T19:59:23Z,2021-10-28T19:59:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89686,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['impedance-based monitoring', 'in-situ detection', 'build defects', 'additive manufacturing']",In-situ Detection of Build Defects in Additive Manufacturing via Impedance-Based Monitoring,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f53c097e-3860-4ebf-b7c5-fd207bd3915b/download,University of Texas at Austin,"In this paper, the authors explore the use of impedance-based monitoring techniques for the in-situ detection of additive manufacturing build defects. By physically coupling a piezoceramic
(PZT) sensor to the part being fabricated, the measured electrical impedance of the PZT can be
directly linked to the mechanical impedance of the part. It is hypothesized that one can detect in-situ defects of part mass and stiffness by comparing the signatures collected during printing of
parts with that of a defect-free control sample. In this paper, the authors explore the layer-to-layer sensitivity of this technique. A control sample is created using Material Jetting and the
change in signatures between various layer intervals is measured. To evaluate the technique’s
ability to perform in-situ detection, several parts containing designed defects (e.g., internal voids)
are fabricated and their layer-to-layer signatures are compared to a control sample. Using this
technique, the authors demonstrate an ability to track print progress and detect defects as they
occur.",,,,,,
"['Pustinger, Alexander P.', 'Corral, Joselin', 'Villegas, Arianna', 'Espalin, David']",2024-03-26T20:56:41Z,2024-03-26T20:56:41Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124409', 'https://doi.org/10.26153/tsw/51017']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['hybrid AM', '4-wire resistance measurements', 'encapsulation', 'laser soldering']",In-situ Electrical Resistance Measurements for Soldering Studies in Hybrid AM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/acb58f4a-95aa-43a4-90b9-1233901d5c2b/download,University of Texas at Austin,"This report was prepared as an account of work sponsored by an agency of the United States
Government. Neither the United States Government nor any agency thereof, nor any of their
employees, makes any warranty, express or implied, or assumes any legal liability or
responsibility for the accuracy, completeness, or usefulness of any information, apparatus,
product, or process disclosed, or represents that its use would not infringe privately owned rights.
Reference herein to any specific commercial product, process, or service by trade name, trademark,
manufacturer, or otherwise does not necessarily constitute or imply its endorsement,
recommendation, or favoring by the United States Government or any agency thereof: The views
and opinions of-authors expressed herein do not necessarily state or reflect those of the-United
States Government or any agency thereof.",,,,,,
"['Liu, Tao', 'Kinzel, Edward C.', 'Leu, Ming C.']",2023-01-27T17:46:09Z,2023-01-27T17:46:09Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117345', 'http://dx.doi.org/10.26153/tsw/44226']",,2022 International Solid Freeform Fabrication Symposium,Open,Laser powder bed fusion (L-PBF),In-situ Infrared Thermographic Measurement of Powder Properties in Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c782c1e4-b67c-4899-ba1e-20e0235060e3/download,,"The laser powder-bed fusion (LPBF) process is strongly influenced by the characteristics 
of the powder layer, including its thickness and thermal transport properties.  This paper presents 
an investigation of in-situ characterization of the powder layer using active infrared thermography.  
The printing laser beam is diffused and illuminates onto the powder bed’s top surface in various 
frequencies.  A long-wavelength thermal camera monitors the surface temperature history.  Insight 
is provided by a one-dimensional thermal model of the process, which shows the frequency 
dependence of the surface temperature amplitude and phase on the powder layer thickness and 
thermal properties. An experiment demonstrates the validity of this model and shows its potential 
for measuring local powder properties in-situ.",,,,,,
"['Binder, Maximilian', 'Machnik, Andreas', 'Bosch, Maximilian', 'Kreitz, Katharina', 'Schlick, Georg', 'Seidel, Christian']",2023-02-10T14:19:04Z,2023-02-10T14:19:04Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117452', 'http://dx.doi.org/10.26153/tsw/44333']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser-Based Powder Bed Fusion', 'Metal Additive Manufacturing', 'Strain Gauges', 'Smart Parts', 'Inconel']",In-situ Integration of Weldable Strain Gauges in Components Manufactured by Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50bf2a7c-7ecd-47de-80bf-46bd093ea70a/download,,"The integration of sensors in components made by PBF-LB/M facilitates promising 
new possibilities for component monitoring. It enables the collection of relevant 
measurement data at previously inaccessible component regions, which are needed for 
the determination of maintenance strategies. Therefore, the following research deals with 
the development of a concept, with which weldable strain gauges (WSG) can be weld-on 
by the laser-scanner-system of a PBF-LB/M system to the manufactured component. The 
examinations show that the arrangement of so-called weld seams has a decisive influence 
on a correct metal carrier connection of the WSG. It can be deduced from the study that 
WSGs can be integrated within components manufactured by PBF-LB/M and completely 
welded to it with the laser-scanning-system. Following measurement validations 
demonstrate that the WSG provides complete and correct measurement data and can 
therefore be considered as successfully connected to the component.",,,,,,
"['Phillips, Tim', 'McElroy, Austin', 'Fish, Scott', 'Beaman, Joseph']",2021-10-28T19:43:05Z,2021-10-28T19:43:05Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89681,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['in-situ laser control', 'selective laser sintering', 'even melting']",In-Situ Laser Control Method for Polymer Selective Laser Sintering (SLS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/0867cd12-72f6-464b-a706-bc894a175bcf/download,University of Texas at Austin,"Selective laser sintering (SLS) of Nylon is a significant portion of the Additive
Manufacturing (AM) market for structurally sensitive applications. To achieve high
performance in these laser melted parts, one would like to see consistent melting of the powder
over the part region in each layer of the build. Current research methods into improving this
consistency focus on the use of IR sensing to adjust heating elements in attempt to gain even
temperature distributions over the pre-laser melted powder layer with the expectation that the
laser at constant power, speed, spot size, and spacing will deliver constant melting properties. In
this paper we examine a complimentary method of gaining even melted properties by sensing the
pre-lased powder along the laser track, and adjusting the laser power to achieve a common post
melted temperature everywhere on the part. We describe the feedback based laser control method
that varies the laser power in to account for the pre-sintering temperature profile across the part
bed. Various tests have been performed, and a method for employing this strategy throughout a
build is presented.",,,,,,
"['Esfahani, Mehrnaz Noroozi', 'Bian, Linkan', 'Tian, Wenmeng']",2021-11-16T16:15:04Z,2021-11-16T16:15:04Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90330', 'http://dx.doi.org/10.26153/tsw/17251']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['image series analysis', 'quality monitoring', 'in-situ', 'layer-wise', 'laser-based additive manufacturing']",In-Situ Layer-Wise Quality Monitoring for Laser-Based Additive Manufacturing Using Image Series Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c3092d6-2b0d-43b3-b20b-998826a5ac52/download,University of Texas at Austin,"Quality assurance has been one of the major challenges in laser-based additive manufacturing
(AM) processes. This study proposes a novel process modeling methodology for layer-wise in-situ
quality monitoring based on image series analysis. An image-based autoregressive (AR) model
has been proposed based on the image registration function between consecutively observed
thermal images. Image registration is used to extract melt pool location and orientation change
between consecutive images, which contains sensing stability information. Subsequently, a
Gaussian process model is used to characterize the spatial correlation within the error matrix.
Finally, the extracted features from the aforementioned processes are jointly used for layer-wise
quality monitoring. A case study of a thin wall fabrication by a Directed Laser Deposition (DLD)
process is used to demonstrate the effectiveness of the proposed methodology.",,,,,,
"['Lough, Cody S.', 'Wang, Xin', 'Landers, Robert G.', 'Bristow, Douglas A.', 'Drallmeier, James A.', 'Kinzel, Edward C.']",2021-11-18T18:47:36Z,2021-11-18T18:47:36Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90464', 'http://dx.doi.org/10.26153/tsw/17385']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['local part qualification', 'local part prediction', 'voxel based processing', 'SWIR imaging', '304L', 'stainless steel', 'selective laser melting']",In-situ Local Part Qualification of SLM 304L Stainless Steel through Voxel Based Processing of SWIR Imaging Data,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c7daaedd-37f9-48eb-89d8-8f363c19dc45/download,University of Texas at Austin,"This paper demonstrates the potential for qualification through local part property
prediction of 304L stainless steel parts manufactured by Selective Laser Melting (SLM). This is
accomplished through voxel based processing of SWIR imaging data measured in-situ. Thermal
features are extracted from time-series SWIR imaging data recorded from layer-to-layer to
generate 3D point cloud reconstructions of parts. The voxel based data is indexed with localized
measurements of SLM part properties (light-to-dark microstructural feature ratio, microhardness,
μCT data) to demonstrate the correlations. Various features are extracted from the thermal history
for comparison of their respective abilities to predict the resulting local part properties. The
correlations and comparisons developed in this paper are then used to discuss the capability of a
voxel based framework using information from in-situ measurements of the thermal history to
locally qualify parts manufactured by SLM.","This work was funded by the Department of Energy’s
Kansas City National Security Campus which is operated and managed by Honeywell Federal
Manufacturing Technologies, LLC under contract number DE-NA0002839.",,,,,
"['Ritchie, M.', 'Mehraban, S.', 'Brown, S.G.R.', 'Butcher, D.', 'Cullen, J.', 'Calvo-Dahlborg, M.', 'Lavery, N.P.']",2023-03-29T16:43:14Z,2023-03-29T16:43:14Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117685', 'http://dx.doi.org/10.26153/tsw/44564']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['High Entropy Alloy', 'Laser Powder Bed Fusion', 'Pitting Corrosion']","In-situ Modification of a High Entropy Alloy with 2.4% Molybdenum Using LPBF, and Its Effect on Microstructure and Corrosion Resistance",Conference paper,https://repositories.lib.utexas.edu//bitstreams/74c72927-f280-444c-aafc-f0abe26dde2f/download,,"Laser powder bed fusion (LPBF) components display higher porosity compared to parts 
made by conventional processes and these pores act as preferential initiation sites for pitting 
corrosion to occur. In stainless steels such as 316L, molybdenum is 3.5X more effective at 
enhancing the pitting resistance than chromium, without adding unwanted nitrides to the alloy. 
In this work, the effect on corrosion resistance is reported for an Al-Cr-Mn-Ni-Fe high entropy 
alloy (HEA) gas atomised specifically for LPBF, as well as the effects of modifying the alloy 
by blending the HEA with molybdenum. In-situ LPBF processing, even for low levels of 
additions has made the comparison difficult, as the pitting resistance is so strongly linked to 
the porosity, which is higher in the in-situ process. Pitting resistance for both the original HEA 
and the doped HEA will be compared between samples processed by casting and by LPBF.",,,,,,
"['Roach, M.A.', 'Fowler, B.', 'Thakkar, D.', 'Babbitt, C.', 'Khurana, S.', 'Jared, B.H.']",2023-04-03T15:54:26Z,2023-04-03T15:54:26Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117720', 'http://dx.doi.org/10.26153/tsw/44599']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Laser powder bed fusion,In-situ Monitoring of Laser-Powder-Bed-Fusion Using IR and NIR Emissions to Detect Thermal Anomalies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08dbecf1-84d9-452b-9575-bb8ff75c6e4c/download,,"Process monitoring of laser-powder-bed-fusion (L-PBF) has advanced significantly since the beginning 
of this technology. Many methods exist today for in-situ process monitoring; however, these methods can be 
costly to implement and provide sub-par image resolutions. This research aims to develop a method of low-cost 
and high-resolution thermal monitoring system using near-infrared (NIR) wavelength band emission monitoring 
to detect anomalies. This research will compare more expensive infrared (IR) wavelength band monitoring 
methods to the cheaper NIR method and other drawbacks brought about by monitoring one wavelength band over 
the other.",,,,,,
"['Nadimpalli, Venkata Karthik', 'Na, Jeong K.', 'Bruner, Darren T.', 'King, Brenna A.', 'Yang, Li', 'Stucker, Brent E.']",2021-10-28T20:36:38Z,2021-10-28T20:36:38Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89694,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['in-situ non-destructive evaluation', 'in-situ monitoring', 'ultrasonic transducer', 'ultrasonic additive manufacturing']",In-Situ Non-Destructive Evaluation of Ultrasonic Additive Manufactured Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bde5037a-d2ad-4262-85e7-843b3ceb2395/download,University of Texas at Austin,"In-situ monitoring of Ultrasonic Additive Manufacturing (UAM) process is crucial for
producing parts suitable for load-bearing structural applications. Due to the nature of UAM
process, it is necessary to monitor the entire build as opposed to only the just bonded layer. For
this purpose, an ultrasonic transducer is used in this study to perform in-situ nondestructive
evaluation (NDE) of the entire build after the addition of each new layer. This has been
successfully implemented first on a manually operated research UAM machine and then applied
on a fully automated commercial grade UAM machine. The practical applications of such in-situ
measurements for ensuring defect-free part fabrication through closed-loop control of the UAM
process control is shown to be possible from the results of this work.",,,,,,
"['Lough, Cody S.', 'Escano, Luis I.', 'Qu, Minglei', 'Smith, Christopher C.', 'Landers, Robert G.', 'Bristow, Douglas A.', 'Chen, Lianyi', 'Kinzel, Edward C.']",2021-11-15T22:19:33Z,2021-11-15T22:19:33Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90292', 'http://dx.doi.org/10.26153/tsw/17213']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['optical emission spectroscopy', '304L', 'stainless steel', 'in-situ', 'selective laser melting']",In-Situ Optical Emission Spectroscopy during SLM of 304L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/367c44d8-7526-4006-acec-651fa4bff5be/download,University of Texas at Austin,"This paper demonstrates the potential of in-situ Optical Emission Spectroscopy (OES) to
monitor the Selective Laser Melting (SLM) process. A spectrometer is split into the beam path of
a home-built SLM system to collect visible light emitted from the melt pool and plume. The inline configuration allows signal collection regardless of the laser scan location. The spectral data
can be used to calculate the temperature of the vapor plume and correlated with the melt-pool size.
The effects of varying the atmosphere and pressure on the OES signal are also explored. These
results demonstrate that OES can provide useful feedback to the SLM process for process
monitoring and part validation. The challenges implementing OES in-line on a commercial SLM
platform are discussed.","This work was funded by Honeywell Federal Manufacturing &
Technologies under Contract No. DE-NA0002839 with the U.S. Department of Energy.",,,,,
"['Legesse, Fisseha', 'Kapil, Sajan', 'Chabra, Rimpy', 'Sharma, Arun', 'Karunakaran, K.P.']",2021-10-26T19:33:27Z,2021-10-26T19:33:27Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89566,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['in-situ preheating', 'solidification cracking', 'hybrid layered manufacturing', 'metal inert gas', 'tungsten inert gas']",In-Situ Preheating in Hybrid Layered Manufacturing for Tooling Elements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e530069f-eba9-48ce-ac73-9efc2c20ddc7/download,University of Texas at Austin,"Solidification cracking of hard materials such as H13 tool steel is one of the major
problems in metal based Additive Manufacturing (AM) processes. Hybrid Layered
Manufacturing (HLM) is one of the metal based AM process which uses Metal Inert Gas (MIG)
cladding for addition and CNC milling for subtraction of material. In this work, an in-situ
induction heating based preheating system has been developed to solve the solidification
cracking problem. The Tungsten Inert Gas (TIG) and Induction heating methods are compared
and it has been found that the induction based preheating system can produce better
microstructure and sound products. In the experimental procedure, before deposition of a layer
the prebuild layer is preheated up to 350-5000C. Also the effect of in-situ preheating on the
microstructure of the deposited layers have been studied using Scanning Electron Microscope
(SEM).",,,,,,
"['Lewis, Adam', 'Gardner, Michael', 'McElroy, Austin', 'Milner, Thomas', 'Fish, Scott', 'Beaman, Joseph']",2021-10-28T19:46:04Z,2021-10-28T19:46:04Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89682,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['optical coherence tomography', 'selective laser sintering', 'in-situ process monitoring', 'ex-situ part quality']",In-Situ Process Monitoring and Ex-Situ Part Quality Assessment of Selective Laser Sintering Using Optical Coherence Tomography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/23881d3c-6d43-4163-a5d1-91b67e365a8e/download,University of Texas at Austin,"Widespread commercial adoption of Selective Laser Sintering has been hindered by
inadequate quality and consistency of manufactured parts. Improved process monitoring and
control have the potential to improve part quality and thus increase adoption of SLS for various
applications. In this paper, optical coherence tomography (OCT) is explored as a new process
monitoring tool in SLS polymer printing. The basic operating principles behind OCT are
reviewed to illustrate the potential monitoring capabilities followed by results for both in-situ
process monitoring and ex-situ examinations of built parts comprised of various
polymers. Capabilities and limitations of OCT in each application are discussed.",,,,,,
"['Guess, T.R.', 'Chambers, R.S.']",2018-10-05T17:28:50Z,2018-10-05T17:28:50Z,1995,Mechanical Engineering,doi:10.15781/T2QZ2327H,http://hdl.handle.net/2152/68718,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['3D Printing', 'cure shrinkage', 'laser path dependance']",In-Situ Property Measurements On Laser-Drawn Strands Of SL 5170 EPOXY and 5149 Acrylate,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c0c9b8f-cd63-4552-b1e4-951983350b45/download,,"Material behavior plays a significant role in the mechanics leading to internal
stresses and, potentially, to distortion (curling) of parts as they are built by
stereolithography processes that utilize photocuring resins. A study is underway to
generate material properties that can be used to develop phenomenological material
models of epoxy and acrylate resins. Strand tests are performed in situ in a 3D
System's SLA-250 machine; strands are drawn by either single or multiple exposures
ofthe resin to a laser beam. Linear shrinkage, cross-sectional areas, cure shrinkage
forces and stress-strain data are presented. Also, the curl in cantilever beam
specimens, built with different draw patterns, are compared.",,,,,,
"['Aminzadeh, Masoumeh', 'Kurfess, Thomas']",2021-10-28T19:50:33Z,2021-10-28T19:50:33Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89683,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'in-situ quality inpsection', 'visual camera images', 'high-resolution imaging']",In-Situ Quality Inspection of Laser Powder-Bed Fusion Using High-Resolution Visual Camera Images,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6047f28b-55dd-4d38-a4ca-8726295fef4d/download,University of Texas at Austin,"Issues of part quality in terms of quality of fusion and formed porosity are widely known
and stated as some of the important challenges with laser powder-bed fusion (LPBF) process. This
paper addresses the in-situ inspection of layer-wise part quality using visual camera images. High-resolution visual images are captured from each layer of the part during LPBF process. The
imaging and illumination setups are developed such that the produced images visualize detailed
surface characteristics of each layer of the build such as fused seams, as well as the individual
formed pores. To enable automated inspection of these images, appropriate image processing
algorithms are developed to detect individual pores formed in each layer. In addition to detection
of individual pores, intelligent pattern matching algorithms are developed, trained, and
implemented to identify porous regions from non-porous layers. The surface characteristics of the
layers as visualized in camera images can also provide a measure of quality of fusion and the
energy of the layer, and an estimated level of porosity. Discussion on characterization of the
surface quality in terms of roughness, quality of fusion, and the energy of the build will be made.
The results of the automated image analyses provide useful feedback for in-situ process
modification as well as part quality assessment.",,,,,,
"['Ganesh-Ram, A.', 'Tanrikulu, A.A.', 'Valdez Loya, O.', 'Davidson, P.', 'Ameri, A.']",2024-03-26T20:58:59Z,2024-03-26T20:58:59Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124410', 'https://doi.org/10.26153/tsw/51018']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'in-situ strengthening', 'Ti6Al4V']",In-situ Reinforcement Processing for Laser Powder Bed Fused Ti64 Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4cf86b2-e821-41f4-b717-2cf4e7430d08/download,University of Texas at Austin,"The objective of this study was to investigate how the microstructure and mechanical properties
of Ti-6Al-4V samples, fabricated using laser powder bed fusion (L-PBF), change when a
predefined local double melting strategy is employed within each layer of the manufacturing
process. The analysis primarily focused on evaluating microstructural aspects, defects, and grain
size, along with the mechanical properties, specifically the Vickers hardness at various positions
within the samples. The findings indicated that the integration of the predefined locally double
melting scan in each layer had a significant influence on the microstructure, resulting in variations
in grain size across different locations, as well as hardness values with variations of up to 10%
across different areas. Moreover, these discoveries underscore the potential of employing the
predefined locally double melting strategy in each layer to create fabricated components with
distinctive behaviors, like composites, which could find applications in the aerospace industry.",,,,,,
"['Wroe, Walker', 'Gladstone, Jessica', 'Phillips, Timothy', 'McElroy, Austin', 'Fish, Scott', 'Beaman, Joseph']",2021-10-20T22:51:55Z,2021-10-20T22:51:55Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89382,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'Nylon-12', 'thermal conditions', 'tensile properties', 'layer-by-layer']",In-Situ Thermal Image Correlation with Mechanical Properties of Nylon-12 in SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1feb92e4-102a-4b93-9594-f619380007d6/download,University of Texas at Austin,"Selective laser sintering (SLS) of Nylon is a significant portion of the additive
manufacturing market for structurally sensitive applications. Current methods of
acceptance for such parts are based on the inclusion of ASTM tensile test specimens
within the build volume to assess the overall build quality. Ultimate strength and
elongation of these specimens oriented both in-plane and normal to the layer build
direction are the primary quality metrics. This paper looks at a more complete method of
certifying parts for acceptance based on examination of the build conditions in each layer
of the part by comparing layer-by-layer thermal conditions during the part build to the
resulting ASTM specimen tensile properties. Through such a comparison, a more
complete three-dimensional assessment of part quality during the build process can be
constructed. The layer-by-layer assessment used here is derived from infrared thermal
imaging; mapping temperature profiles of SLS-built tensile bars with data collected
before, during, and after each layer-wise laser melting sequence. Mechanical properties
and fracture conditions are then quantified and correlated with the conditions where the
fractures occur. Build conditions associated with poor failure conditions may then be
used to assess poor SLS bonding throughout the part volume, improving overall part
quality assessment and certification. As the method is matured, real time layer-by-layer
assessment will be linked to SLS control, to correct for observed defects during the build
and improve overall part quality and repeatability.",,,,,,
"['Liu, T.', 'Lough, C.S.', 'Sehhat, H.', 'Huang, J.', 'Kinzel, E.C.', 'Leu, M.C.']",2021-12-01T22:21:08Z,2021-12-01T22:21:08Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90637', 'http://dx.doi.org/10.26153/tsw/17556']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'long wavelength infrared', 'powder thickness']",In-Situ Thermographic Inspection for Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/31f7cc78-0048-4a65-839a-d73c66a39507/download,University of Texas at Austin,"Laser powder bed fusion is strongly influenced by the quality of the powder layer including the powder properties as
well as the layer thickness. In particular, thermal stresses can produce sufficient part deformation to the point that a
part interferes with the wiper. This paper investigates the use of long-wave infrared thermography to monitor the
surface temperature of the build. When cold powder is spread by the wiper, heat diffuses from the underlying part
through the powder. The surface temperature history is a strong function of the thermal transport properties of the
powder as well as the thickness. This correlation is explored and measured experimentally. It is then used to
estimate the powder layer thickness above overhanging parts. This approach is shown to capture the part distortion
and predicts wiper state prior to catastrophic interaction with the part.",,,,,,
"['AlMangour, B.', 'Grzesiak, D.', 'Yang, J.M.']",2021-10-27T21:04:42Z,2021-10-27T21:04:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89613,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['mechanical alloying', 'selective laser melting', 'porosity', 'hardness', 'wear']",In-Situ TiC Particle Reinforced 316L Stainless Steel Matrix Nanocomposites: Powder Preparation by Mechanical Alloying and Selective Laser Melting Behavior,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63bab039-4ce4-4d99-998b-99c25275b573/download,University of Texas at Austin,,,,,,,
"Ahlers, Daniel",2021-12-01T22:24:42Z,2021-12-01T22:24:42Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90638', 'http://dx.doi.org/10.26153/tsw/17557']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['printed electronics', 'visual inspection', 'neural network', 'fused filament fabrication']",In-Situ Verification of 3D-Printed Electronics Using Deep Convolutional Neural Networks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/494dd034-3aae-4ee7-a1bc-c27e4f94a495/download,University of Texas at Austin,"Printed electronics processes are becoming more stable and evolve into first industrial applications. These industrial applications require proper quality assurance to get a mostly autonomous
production process. In this work, we present a new approach to inspect printed electronics and
ensure their quality. Our hardware setup extends a fused filament fabrication (FFF) printer with
an extruder for direct dispensing of conductive paste, a pick and place unit, and two cameras. The
cameras take multiple images during printing. A trained neural network analyzes these pictures
to separate the electronic wires from the plastic background. All separated images of a layer are
combined to get a full view of the layer. Our algorithms then examine the detected wires to identify
printing flaws. The algorithms currently detect connection breaks, shorts, find points that have not
been reached, and evaluate the width of the printed wires.",,,,,,
"['Karnati, Sreekar', 'Hoerchler, Jack', 'Flood, Aaron', 'Liou, Frank']",2021-11-11T15:02:44Z,2021-11-11T15:02:44Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90211', 'http://dx.doi.org/10.26153/tsw/17132']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['automated ball indentation', 'plastic behavior', 'Power Law', '304L', 'stainless steel', 'powder bed fabrication']",Incorporation of Automated Ball Indentation Methodology for Studying Powder Bed Fabricated 304L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f2399ee-df11-476a-baee-ae70bcf10248/download,University of Texas at Austin,"Automated Ball Indentation (ABI) is a viable method for estimating the ductility, yield
stress, and ultimate stress, among other metrics, in different metallic materials. Currently, ABI
data analysis utilizes Holloman’s Power Law to model the plastic region of the true stress-true
strain curve. While this formulation is accurate for some materials, its relevance for additively
manufactured austenitic stainless steels, such as 304L, needed investigation. The deviation of the
material’s plastic behavior from the Power Law was investigated. In order to better model this
behavior, both the Voce and Ludwigson formulation were investigated. These formulations were
tested for both wrought and additively manufactured 304L stainless steel. Regression analysis was
used to choose the appropriate fit. The chosen formulation was then used to generate a material
model to simulate the ABI process. These simulations were validated through experimental
analysis.",,,,,,
"['Leu, Ming C.', 'Isanaka, Sriram P.', 'Richards, Von L.']",2021-09-28T19:28:54Z,2021-09-28T19:28:54Z,9/22/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88161', 'http://dx.doi.org/10.26153/tsw/15102']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Rapid Freeze Prototyping', 'heat transfer', 'build time reduction']",Increase of Heat Transfer to Reduce Build Time in Rapid Freeze Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7007eb7-8af3-4d38-aa03-b6a345ee5dce/download,University of Texas at Austin,"Reduction of part build time in the Rapid Freeze Prototyping (RFP) process,
which fabricates a 3D ice part layer-by-layer by depositing and freezing water droplets,
has been achieved by increase of heat transfer. Three mechanisms have been
experimentally investigated: 1) cooling the substrate, 2) use of forced convection, and 3)
use of a chilling plate. Cooling the substrate is effective for parts of small heights but
becomes ineffective with increase in part height. Forced convection produced desirable
reduction in part build time but with the undesirable formation of frost on the built ice
part. The use of chilling plate to increase heat conduction proved to be most effective. To
ensure that the frozen ice from the deposited water can be easily removed from the
chilling plate, various surface coats were investigated and the most effective surface coat
was found to be a thin Teflon film. After incorporating the chilling plate we have
successfully achieved 75% reduction in part build time.",,,,,,
"['Roschli, Alex', 'Duty, Chad', 'Lindahl, John', 'Post, Brian K.', 'Chesser, Phillip C.', 'Love, Lonnie J.', 'Gaul, Katherine T.']",2021-11-09T19:14:35Z,2021-11-09T19:14:35Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90135', 'http://dx.doi.org/10.26153/tsw/17056']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['z-pinning', 'interlaminar strength', 'large scale additive manufacturing', 'big area additive manufacturing', 'BAAM']",Increasing Interlaminar Strength in Large Scale Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8a660f19-abef-4da5-ad49-fa4f7e2c8390/download,University of Texas at Austin,"Interlaminar strength of extrusion-based additively manufactured parts is known to be
weaker than the strength seen in the printed directions (X and Y). With Big Area Additive
Manufacturing (BAAM), large parts lead to long layer times that are prone to splitting,
sometimes referred to as delamination, between the layers. Fiber filled materials, such as carbon
fiber reinforced ABS, are used to counteract the effects of thermal expansion by increasing the
strength in the X and Y directions. These fibers stay in-plane meaning that no fibers span from
layer to layer, which would help counteract the weak interlaminar strength that causes splitting.
A solution to this is a patent pending approach called Z-Pinning. The process involves
strategically positioning voids across multiple layers that are backfilled with hot extrudate. This
paper will explore the benefits and results of using Z-Pinning in large scale additive
manufacturing.",,,,,,
"['Ahlers, D.', 'Koppa, P.', 'Hengsbach, F.', 'Gloetter, P.', 'Altmann, A.', 'Schaper, M.', 'Tröster, T.']",2021-11-04T13:52:37Z,2021-11-04T13:52:37Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89960,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['process melting', 'porosity', 'Ti6Al4V', 'hot isostatic pressing', 'selective laser melting']",Increasing Process Speed in the Laser Melting Process of Ti6Al4V and the Reduction of Pores During Hot Isostatic Pressing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d2a0a259-f930-4a05-b6b5-58190214ce4c/download,University of Texas at Austin,"Additive manufacturing of titanium alloys has gained intensive attraction from industry and
academia. Moreover, for additively fabricated parts consisting of Ti6Al4V, hot isostatic pressing
(HIP), is widely used as a post treatment in order to increase the relative density of the built parts.
However, one aspect which has rarely been addressed so far, is the increase of process speed,
accompanied by a reduced relative density in the as-built condition and a subsequent hot isostatic
pressing process to achieve the desired dense material. The approach here is to use the standard
process route as described, but intentionally increase the process speed and accept a certain value
of porosity. The focal objective of this study is the identification of a parameter-set with the highest
potential for an increase of process speed and subsequently reduce the internal defects during the
hot isostatic pressing process to achieve completely dense components.",,,,,,
"['Duty, Chad', 'Smith, Tyler', 'Lambert, Alexander', 'Condon, Justin', 'Lindahl, John', 'Kim, Seokpum', 'Kunc, Vlastimil']",2021-11-18T19:15:18Z,2021-11-18T19:15:18Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90475', 'http://dx.doi.org/10.26153/tsw/17396']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['z-pinning', 'solid cross-section', 'interlayer bond', 'fused filament fabrication']",Increasing the Interlayer Bond of Fused Filament Fabrication Samples with Solid Cross-Sections using Z-Pinning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56532fac-e5bf-444b-b9c9-8b5b35fac9ac/download,University of Texas at Austin,"The mechanical properties of parts made by fused filament fabrication is highly anisotropic,
with the strength across layers (z-axis) typically measuring ~50% lower than the strength along
the direction of the extruded material (x-axis). A z-pinning method has been developed in which
material is extruded in the z-direction to fill intentionally aligned voids in the x-y print pattern. In
previous studies that involved a sparse rectilinear grid cross-section (35% infill), the z-pinning
approach demonstrated more than a 3.5x increase in strength in the z-direction. The current study
expanded these efforts to evaluate the use of z-pins in a printed sample with a solid cross-section.
Although a solid cross-section is more common in structural components, it is much less forgiving
of instabilities that may occur in the z-pinning approach (such as over-filling). Even though this
study utilized a low pin volume (~43% fill factor), the pinning approach demonstrated a 40%
increase in z-direction strength for solid samples that had similar printing times.",,,,,,
"['Mun, Jiwon', 'Ju, Jaehyung', 'Thurman, James']",2021-10-13T20:40:28Z,2021-10-13T20:40:28Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88781', 'http://dx.doi.org/10.26153/tsw/15715']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['indirect additive manufacturing based casting', 'I AM Casting', 'indirect 3D printing based casting', 'metallic cellular structures', 'PolyJet', 'volume of fluid', 'additive manufacturing']",Indirect Additive Manufacturing of a Cubic Lattice Structure with a Copper Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97f124e2-765e-4a7d-9ff1-005054fd5771/download,University of Texas at Austin,"Direct-metal additive manufacturing (AM) processes such as Selective Laser Melting
(SLM) and Electron Beam Melting (EBM) methods are being used to fabricate complex metallic
cellular structures with a laser or electron beam over a metal powder bed. Even though their
excellent capabilities to fabricate parts with cellular mesostructure, there exist several constraints
in the processes and applications; limited selection of materials, high thermal stress by the high
local energy source, poor surface finish and anisotropic properties of parts caused by combined
effects of one-dimensional (1D) energy based patterning mechanism, the deposition layer
thickness, powder size, power and travel speed of laser or electron beam. In addition,
manufacturing cost is still high with the Direct-metal AM processes. As an alternative way to
manufacture metallic 3D cellular structures, which can overcome the disadvantages of direct-metal
AM techniques, polymer AM methods can be combined with metal casting. We may call this
“Indirect AM based Casting (I AM casting)”. The objective of the study is to explore the potential
of I AM Casting associated with development of a novel manufacturing process - Indirect 3D
Printing based casting which is capable of producing metallic cellular structures within a cell size
of 3mm and cell thickness of 0.5mm. We will characterize polymers making sacrificial patterns by
PolyJet typed 3D printers; e.g., melting and glass transition temperatures and thermal expansion
coefficients. A transient flow and heat-transfer analysis of molten metal through 3D cellular
network mold will be conducted. Solidification of molten metal through cellular mold during
casting will be simulated with temperature dependent properties of molten metal and mold over a
range of running temperature. The volume of fluid (VOF) method will be implemented to simulate
the solidification of molten metal together with a user defined function (UDF) of
ANSYS/FLUENT. Finally, experimental validation will be followed.",,,,,,
"['Chakravarthy, Kumaran M.', 'Bourell, David L.']",2021-10-05T14:42:58Z,2021-10-05T14:42:58Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88383', 'http://dx.doi.org/10.26153/tsw/15322']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['direct methanol fuel cells', 'corrugated flow field plates', 'power density', 'laser sintering']",Indirect Laser Sintering of Corrugated Flow Field Plates for Direct Methanol Fuel Cell Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d5db2bd0-d0e1-4d5e-8f4e-f669cc0a48ac/download,University of Texas at Austin,"Direct methanol fuel cells (DMFC) hold distinct advantages over traditional hydrogen-based fuel
cells. Their commercialization, however, has been bound by many factors – especially their suboptimal efficiency. This work aims at enhancing the performance of DMFC through the use of
corrugated flow field plates. Our objectives are two-fold – one, to increase the power density of
DMFC by corrugating flow field plates and two, to introduce Laser sintering (LS) as an efficient
and robust method for the manufacture of such plates. Corrugated flow field plates with 10%
more surface area as compared to a planar design were made by LS & tested in a DMFC
environment. Our results show that the particle size of the material used – Graphite – has a
significant effect upon the green strength of LS parts. We also report the performance of
corrugated flow field plates with 10% higher surface area (as compared to planar plates), channel
width and depth of 2mm and an electrode area of 5 cm2. This study is the first experimental
approach to the use of indirect LS for making such fuel cell components.",,,,,,
"['Tobin, James R.', 'Badrinarayan, B.', 'Barlow, J.W.', 'Beaman, J.J.']",2018-05-03T19:52:50Z,2018-05-03T19:52:50Z,1993,Mechanical Engineering,doi:10.15781/T2H708H81,http://hdl.handle.net/2152/65072,,1993 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Department of Chemical Engineering', 'Department of Mechanical Engineering', 'Selective Laser Sintering', 'SLS']",Indirect Metal Composite Part Manufacture Using the SLS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ad9fd096-f9c3-4e83-9ad8-2b01b0eab9d3/download,,"As a near term alternative process to direct sintering, an intermediate
polymer binder is combined with powder to produce green preforms with the
Selective Laser Sintering (SLS) process. To produce parts with desirable strength
dimensional control, the binder is gradually removed from the green preform
(obtained from the SLS process), and the remaining form is lightly bonded. This
porous part then infiltrated. Final part density, shrinkage, and strength data are
presented. An injection mold insert was fabricated from this material and used to
mold PMMA, polyester, and polycarbonate parts. To date, the mold insert
176 shots at injection to 35,000 and melt
temperatures up to 300°C.",,,,,,
"['Gervasi, Vito R.', 'Shaikh, F. Zafar']",2019-09-23T17:13:27Z,2019-09-23T17:13:27Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75978', 'http://dx.doi.org/10.26153/tsw/3077']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototype,Indirect Rapid Molds for Prototype Lost-Foam Pattern Production 506,Conference paper,https://repositories.lib.utexas.edu//bitstreams/87f984b1-e22e-4902-9796-4a1f30c75633/download,,"Lost-foam (also known as Expendable Pattern Casting, EPC) is an ever-growing metalmcasting technique, capable of producing complex metal components without parting lines. Mold preparation for lost-foam casting is typically accurate, but expensive and slow. The goal of this research was to develop a new approach for producing rapid lost-foam molds. With this new approach, patterns generated by SFF technology are used to form indirect composite lost-foam molds. Ultimately, our objective is to produce these molds quickly, accurately, and inexpensively. This new approach to lost-foam mold-making will be explained as well as the
results of one trial.",,,,,,
"['Vallabhajosyula, Phani', 'Bourell, David L.']",2021-09-29T14:19:20Z,2021-09-29T14:19:20Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88179', 'http://dx.doi.org/10.26153/tsw/15120']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'ferrous components', 'infiltrant composition']","Indirect Selective Laser Sintered Fully Ferrous Components – Infiltration Modeling, Manufacturing and Evaluation of Mechanical Properties",Conference paper,https://repositories.lib.utexas.edu//bitstreams/207a6988-fb5b-4d29-bc14-0015aac38757/download,University of Texas at Austin,"Commercially available Selective Laser Sintered (SLS) ferrous components contain
copper-based infiltrant in a ferrous preform. The choice of infiltrant has led to inferior
mechanical properties of these components limiting their use in many non-injection-molding
structural applications, particularly at elevated temperature. In the present work, an attempt has
been made to replace the copper-based infiltrant considering cast iron as potential infiltrant for
its fluidity, hardness and stability at comparatively high temperature. A critical issue associated
with the infiltration was diffusion of carbon from the cast iron into the steel preform thereby
decreasing its melting temperature and distorting the part geometry. A predictive model was
developed which defines the degree of success for infiltration based on final part geometry and
depending on the relative density of the preform and infiltration temperature. The model may be
extended to other ferrous powder and infiltrant compositions in an effort to optimize the
properties and utility of the final infiltrated part. Initial studies were carried out to validate the
model by infiltrating SLSed Laserformtm A6 tool steel preforms with ASTM Type I A532 cast
iron. The parts were analyzed for geometry, microstructure and hardness. This research was
sponsored by the National Science Foundation under Grant #DMI-0522176.",,,,,,
"['Bernardo, Jesse', 'Samavedi, Satyavrata', 'Williams, Christopher B.', 'Whittington, Abby R.']",2021-10-05T14:30:06Z,2021-10-05T14:30:06Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88379', 'http://dx.doi.org/10.26153/tsw/15318']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'biomimetic mineralization', 'tissue scaffold', 'additive manufacturing']",Indirect Tissue Scaffold Fabrication via Fused Deposition Modeling and Biomimetic Mineralization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e13538a-e2df-4d79-ac97-00459e8bc73c/download,University of Texas at Austin,"To alleviate material limitations of the additive manufacture of tissue scaffolds, researchers have looked to
indirect fabrication approaches. The feature resolution of these processes is limited however, due to the viscous
ceramic slurries that are typically employed. To alleviate these limitations, the authors look to an indirect
fabrication process wherein a pattern, created using Fused Deposition Modeling, is biomimetically mineralized with
an aqueous simulated body fluid, which forms a bonelike hydroxyapatite throughout the scaffold pattern.
Mineralized patters are then heat treated to pyrolyze the pattern and sinter the minerals. With this process, scaffolds
were created with wall thicknesses as small as 150 m and internal channel diameters of 280-340 m, an
appropriate range for bone tissue engineering.",,,,,,
"['Shrestha, Subin', 'Starr, Thomas', 'Chou, Kevin']",2021-11-11T15:16:10Z,2021-11-11T15:16:10Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90216', 'http://dx.doi.org/10.26153/tsw/17137']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['computed tomography', 'porosity', 'selective laser melting']",Individual and Coupled Contributions of Laser Power and Scanning Speed Towards Process-Induced Porosity in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2945cae3-af56-4ce6-88f5-60ff222fcfcb/download,University of Texas at Austin,"Porosity is an undesirable characteristic of selective laser melting (SLM) process and keyhole
pores are formed when the energy density is very high which leads to deep penetration melting.
In this study, single-track SLM experiments using Ti-6Al-4V powder were designed and
conducted with combination of varied levels of the laser power and the scanning speed, intended
to obtain the same energy density. Three energy densities: 0.32 J/mm, 0.4 J/mm and 0.48 J/mm
were selected to investigate the influence of laser power versus scanning speed on porosity. Pore
numbers and volumes was analyzed using micro-scale computed tomography. The results
indicated that the pore formation is affected more by the change in the power than the scanning
speed while keeping the energy density constant. As the power increased from around 20 W to
140 W, total pore volume increased, whereas pore volume decreased when power increased from
140 W to 195W.",,,,,,
"['Omer, L.', 'Uddin, M.J.', 'Chowdhury, H.', 'Martinez, J.', 'Sporn, I.', 'Dudek, B.', 'Tate, J.']",2023-03-29T14:45:38Z,2023-03-29T14:45:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117673', 'http://dx.doi.org/10.26153/tsw/44552']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Fused Filament Fabrication', 'Thermoset Curing', 'Advanced Composites', 'Additive  Manufacturing', 'Polymer Matrix Composites', 'Induction Heating']",Induction Initiated Curing of Additively Manufactured Thermoset Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8dfeebdd-7c0f-4b7b-a33d-d5c8bc76131b/download,,"Additive Manufacturing (AM) has provided a new potential for material customization 
through the reduction in geometric constraints of products. The freeform geometry produced using 
AM allows for the creation of optimized structural parts that reduce weight and material waste. In 
addition, AM reduces production time by providing a model to product workflow with limited 
requirements for tooling and machine setup in advance. However, current work in printing 
thermoset composite parts is limited. One of the confounding factors in the AM of thermoset 
composites involves in situ curing of the composite resin system. This research proposes the 
creation of an additive manufacturing process for thermoset composites based upon induction 
initiated thermoset curing. The use of induction-based curing will allow the production of parts 
without the normal constraint of either oven or autoclave curing. A rapid curing resin system will 
be reinforced using milled fiber reinforcement and doped with a ferromagnetic susceptor to induce 
homogenous heating and curing of the resin in situ. The resulting composite will be evaluated for 
mechanical performance versus oven cure samples. Scanning electron microscopy in tandem with 
energy dispersive x-ray spectroscopy will be used to validate homogenous particle dispersion. 
Lastly, differential scanning calorimetry will be used to compare the degree of polymer conversion 
between induction and conventional curing.",,,,,,
"['Regenfuβ, P.', 'Hartwig, L.', 'Klötzer, S.', 'Ebert, R.', 'Brabant, Th.', 'Petsch, T.', 'Exner, H.']",2020-02-17T15:23:52Z,2020-02-17T15:23:52Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80009', 'http://dx.doi.org/10.26153/tsw/7034']",eng,2004 International Solid Freeform Fabrication Symposium,Open,selective laser sintering,Industrial Freeform Generation of Microtools by Laser Micro Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/640141e0-9cf2-48d1-8894-b5349e5a476d/download,,"Precision tools with structural resolution reaching the 20 micrometer range can be generated
on an industrial scale by “laser micro sintering”. Components featuring aspect ratios above 12
and a roughness Ra down to 1.5 micrometers have already been produced from sub micrometer
grained metal powders. The components can be generated either firmly attached to a substrate or
fixed in an easily separable mode. If supporting structures are employed, undercuts up to 90° are
feasible, without, a process parameter dependent maximum angles of undercut below 90° are
obtained.
The process has been introduced into the market, labeled microSINTERING by
3D-Micromac AG.",,,,,,
"['Nyrhila, Olli', 'Kotila, Juha', 'Lind, Jan-Erik', 'Syvanen, Tatu']",2019-02-26T17:02:42Z,2019-02-26T17:02:42Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73487', 'http://dx.doi.org/10.26153/tsw/637']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Direct Metal Laser Sintering', 'Electrolux Rapid Development']",Industrial Use of Direct Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6cf51b16-edc9-4229-9d70-5202663e15a8/download,,"The Direct Metal Laser Sintering (DMLS) process was developed a few years ago by
Electrolux Rapid Development (ERD) and EOS. DMLS has now been in commercial use for
more than two years at Electrolux and also at other European prototype manufacturers, and
the machine itself is also available for purchase.
This paper describes the development ofthe process in particular the industrialization of
DMLS and how it has changed the prototype mould manufacturing process at Electrolux.
Issues concerning the materials used are also described, as well as the necessary posttreatment methods in prototype mould manufacturing. Several case studies, from various
injection mouldings to pressure die-casting, are presented.",,,,,,
"['Anarfi, Richard', 'Kwapong, Benjamin', 'Fletcher, Kenneth', 'Sparks, Todd', 'Flood, Aaron', 'Joshi, Mugdha']",2021-12-07T17:18:26Z,2021-12-07T17:18:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90726', 'http://dx.doi.org/10.26153/tsw/17645']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'autoencoder', 'deep learning']",Inference of Metal Additive Manufacturing Process States via Deep Learning Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2adee999-13b3-4d7f-8d2d-6fd5cc74db0e/download,University of Texas at Austin,"Numerical simulation of metal additive processes are computationally intensive tasks. Iterative
solution techniques for physics-based methods can lead to lengthy solution times and convergence
problems, particularly if fluid dynamics of the melt pool are considered. Deep learning (DL) techniques offer an opportunity to infer solution results quickly. In this paper we propose a DL method
based on long short term memory (LSTM), network trained on rendered images from a metal AM
process simulation and CAM data. We obtained vector representations of the images by training
on an autoencoder. LSTM is a memory based recurrent neural networks (RNN) that is capable of
processing long sequences of data while combating temporal stability problems encountered with
conventional recurrent neural networks (RNN)s. This LSTM network is used to predict images
of the process given scan path and process information. This could later be used to compare with
process monitoring systems as part of a quality assurance or process control schema.",,,,,,
"['Buls, S.', 'Craeghs, T.', 'Clijsters, S.', 'Kempen, K.']",2021-10-07T17:58:33Z,2021-10-07T17:58:33Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88496', 'http://dx.doi.org/10.26153/tsw/15430']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'galvano based laser scanner', 'total scan time', 'optimization']",The Influence of a Dynamically Optimized Galvano Based Laser Scanner on the Total Scan Time of SLM Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fd1d9c52-3ab6-4dcd-8507-963dca43a45e/download,University of Texas at Austin,"Most commercially available Selective Laser Melting (SLM) machines use galvano based laser scanner
deflection systems. This paper describes the influence of the dynamical optimization of such galvano based
laser scanner on the total scan time. The system identification of a galvano laser scanner was performed in
combination with the development and implementation of an optimal ‘Input Shaper’. Tests were performed on
lattice structured SLM parts. The process time was hereby compared, with and without the use of the optimal
‘Input Shaper’. Significant scan time reduction was observed when using the optimal ‘Input Shaper’.",,,,,,
"['Fashanu, O.', 'Buchely, M.F.', 'Hussein, R.', 'Anandan, S.', 'Spratt, M.', 'Newkirk, J.', 'Chandrashekhara, K.', 'Misak, H.', 'Walker, M.A.']",2021-11-11T14:56:02Z,2021-11-11T14:56:02Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90209', 'http://dx.doi.org/10.26153/tsw/17130']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'SLM', 'stainless steel', 'hatch angle', 'build orientation']",The Influence of Build Parameters on the Compressive Properties of Selective Laser Melted 304L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9200f50-2342-4713-9fef-b5af9024e042/download,University of Texas at Austin,"Process parameters used during Selective Laser Melting (SLM) process have significant effects on
the mechanical properties of the manufactured parts. In this study, the influence of two build
parameters (build orientation and hatch angle) on the compressive properties of 304L stainless
steel was evaluated. SLM 304L samples were manufactured using three hatch angles, 0°, 67°,105°
and two orientations, z-direction and x-direction, and tested using a compression frame according
to ASTM E9-09. Bulk density was measured according to ASTM C373-17 before compression.
Properties evaluated were the bulk density, yield strength, strength at 15% plastic-strain and
strength at 30% plastic-strain. Results showed that bulk density varied minutely with respect to
variation in hatch angle and build orientation, but compressive yield strength and plastic flow stress
were strongly influenced by these two process parameters. Highest compressive yield strength was
measured when samples were built in the x-direction using hatch angle 67°.",,,,,,
"['Kummert, C.', 'Schmid, H.-J.']",2021-11-11T16:11:00Z,2021-11-11T16:11:00Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90231', 'http://dx.doi.org/10.26153/tsw/17152']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['PA613', 'scanning parameters', 'scanning strategy', 'build part properties', 'contour', 'selective laser sintering']",The Influence of Contour Scanning Parameters and Strategy on Selective Laser Sintering PA613 Build Part Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/46a9974c-34db-4817-906b-beda64ecf569/download,University of Texas at Austin,"Qualification of new materials for the laser sintering (SLS) process includes development
of suitable parameters in terms of optimal part properties. Especially laser scanning parameters
influence part porosity and therewith mechanical performance. In the present work tensile
specimens were built of PA613 a new LS polyamide delivered by Evonik and was processed on an
EOSINT P396. As build parameters have to be developed for the new material, scanning
parameters and strategy of the PA613 specimen contour were varied in different ways. Resulting
part properties were investigated by XCT-analysis as well as by tensile tests. The three-dimensional
part porosity, pore density and arrangement were analyzed in relation to used laser scanning
parameters and resulting mechanical properties. The investigations help to understand the existing
correlations between laser energy input, part porosity and mechanical performance and therewith
to find optimized build parameters for the new material.",,,,,,
"['Colton, Trenton', 'Liechty, Joseph', 'McLean, Alden', 'Crane, Nathan']",2021-11-16T15:54:42Z,2021-11-16T15:54:42Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90322', 'http://dx.doi.org/10.26153/tsw/17243']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['drop velocity', 'droplet spacing', 'equilibrium saturation', 'binder jetting']",Influence of Drop Velocity and Droplet Spacing on the Equilibrium Saturation Level in Binder Jetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e771f55-3222-47a3-8181-5738da4caca4/download,University of Texas at Austin,"Understanding the equilibrium saturation level is crucial to Binder Jetting (BJ). Saturation
level influences dimensional accuracy, print time, green strength, and final material properties.
Improved understanding of the saturation level can reduce development time for new materials
and improve existing processes in BJ. Attempts have been made to predict saturation levels of
parts with simple calculations from droplet primitives and capillary pressure. There is, however,
limited experimental validation for these methods and they do not include the impact of drop
velocity and droplet spacing. This study incorporates the influences of drop velocity and droplet
spacing on the saturation level of the part. Drop primitives of varying droplet velocity and droplet
spacing were compared. Results show that velocity impacts the feasible parameter space.",,,,,,
"['Sinha, Swapnil', 'Meisel, Nicholas A.']",2021-10-27T22:43:26Z,2021-10-27T22:43:26Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89637,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['embedding', 'tensile strength', 'material extrusion', '3D printing']",Influence of Embedding Process on Mechanical Properties of Material Extrusion Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2414abcc-f540-4531-9759-2429a1d05771/download,University of Texas at Austin,"The layer-by- layer deposition of material in Additive Manufacturing (AM) introduces the
capability for in-situ embedding of functional components into printed parts. The typical
embedding process involves, i) designing the cavity for the embedded component, ii) pausing the
print when the top layer of the cavity is reached, iii) manually inserting the component, and iv)
resuming the build process. However, the effect of different interfacial materials (due to the
presence or absence of a shape converter) and the pause time during the build process on a part’s
material properties is not well-understood. Therefore, the tensile strength of 3D-printed embedded
specimens with and without shape converters and with different intervals of pause time is tested
in this study. The results from this experimental analysis can be useful for the design guidelines
for AM with embedded components as they provide an initial understanding of mechanical
properties of these parts.",,,,,,
"['Karnati, S.', 'Hoerchler, J.L.', 'Liou, F.', 'Newkirk, J.W.']",2021-11-02T15:03:15Z,2021-11-02T15:03:15Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89821,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['304L', 'stainless steel', 'miniature tensile specimens', 'tensile strength', 'gage length', 'powder bed additive manufacturing']",Influence of Gage Length on Miniature Tensile Characterization of Powder Bed Fabricated 304L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/628d1ecb-28f8-4008-8d69-0e70d44cfd13/download,University of Texas at Austin,"Miniature tensile specimens with varying aspect ratios were fabricated from 304L stainless steel
(SS) made using powder bed additive manufacturing (AM) process. The tensile characteristics
measured from these specimens were analyzed to assess the impact of gage length. The study
found no impact upon varying gage length on yield and ultimate strength measurements.
However, a significant impact was observed on strain measurements. This data was also used to
perform Weibull statistics to estimate the stochastic performance of the material. Fractography
was performed to visually identify the types of flaws. A comparative study with specimens
fabricated from cold rolled annealed 304 SS was also performed. The Weibull parameters were
used to compare the variability within cold rolled annealed and AM 304L SS. This study
indicates miniature tensile testing is a robust characterization technique for obtaining
representative material properties.",,,,,,
"['Saunders, R.', 'Achuthan, A.', 'Iliopoulos, A.', 'Michopoulos, J.', 'Bagchi, A.']",2021-11-11T16:45:40Z,2021-11-11T16:45:40Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90244', 'http://dx.doi.org/10.26153/tsw/17165']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['grain aspect ratio', 'grain size', 'grain loading direction', 'grain shape', 'metal additive manufacturing', 'powder-based additive manufacturing', 'PAM']",Influence of Grain Size and Shape of Mechanical Properties of Metal AM Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f30b3d74-9f84-471d-a419-de4c54b085e3/download,University of Texas at Austin,"Metal powder-based additive manufacturing (PAM) typically results in microstructures
with a texture and columnar grain structure. The columnar grains can vary greatly in size and
shape throughout the microstructure, which can significantly affect the mechanical properties of
the resulting part. A previous study developed a microstructurally informed crystal plasticity constitutive model that took into account grain sizes and shapes then showed that grain geometry can
influence the prediction of mechanical behavior of the part. In the present work, the influence of
grain aspect ratio, size, and loading direction on the resulting mechanical properties of the PAM
part are investigated through a parametric study. Results show that considering size and shape
effects have the tendency to increase the material yield strength while decreasing the initial strain
hardening modulus. Using this knowledge, it may be possible to optimize a PAM microstructure
using process parameters to produce a part which exhibit superior yield strength and hardening
modulii compared to traditional materials.",,,,,,
"['Sesseg, Jens P.W.', 'Riedmann, Paul', 'Fischer, Sybille', 'Schmid, Hans-Joachim']",2021-12-01T23:53:13Z,2021-12-01T23:53:13Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90664', 'http://dx.doi.org/10.26153/tsw/17583']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser sintering', 'polymer', 'grain size distribution', 'powder rheology', 'polyamide 12']",The Influence of Grain Size Distribution of PA12 on Key Steps of the Polymer Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4c9b28f7-b081-4ce1-99b6-d30cc113c78c/download,University of Texas at Austin,"As the industry pushes for higher resolution laser sintering, finer and finer powders
are required. Yet, this also changes the way powders behave during the process. In this
project, the influence of finer particles on the dosing and coating process during laser
sintering is being investigated. PA12 laser sintering powder without flow additives was
sieved to four fractions with grain sizes with a d50 of 42, 54, 61 and 66 µm. These fractions
were characterized regarding powder flowability by FT4 powder rheometer. The dosing
and coating behavior of these fractions was tested in separate experiments on an EOS
P395, where the coating experiments were performed at both RT and 175°C.
Furthermore, test jobs were built with the different powder fractions. The larger portion of
fines in the finest fraction dominated the powder properties and led to significantly worse
powder behavior during the dosing and coating steps, as predicted by analytical
measurements.",,,,,,
"['Thöne, M.', 'Leuders, S.', 'Riemer, A.', 'Tröster, T.', 'Richard, H.A.']",2021-10-06T20:17:39Z,2021-10-06T20:17:39Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88431', 'http://dx.doi.org/10.26153/tsw/15368']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['heat treatment', 'selective laser melting', 'Ti6Al4V', 'titanium alloys']",Influence of Heat-Treatment of Selective Laser Melting Products - e.g. Ti6Al4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed41d5f2-7453-4bde-9353-da484c5f966c/download,University of Texas at Austin,"Usually additive manufactured metal parts are showing a different mechanical behavior compared to
conventionally produced parts used the same material. Apart from process-related macroscopic part
imperfections (pores, surface roughness, etc.) the microstructure has a decisive influence on the mechanical
properties of the materials. Thus, in order to optimize mechanical properties of metal parts a heat treatment for
changing microstructures is routinely applied in most production lines to meet the product requirements. By
means of the Titanium alloy Ti6Al4V the optimization of the static- and the fracture mechanical behavior by
changing the microstructure with a heat treatment after the SLM process is discussed on the present work.",,,,,,
"['Khalil, Y.', 'Hopkinson, N.', 'Kowalski, A.', 'Fairclough, J.P.A.']",2021-10-27T22:36:35Z,2021-10-27T22:36:35Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89635,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'UHMWPE', 'laser sintering', 'laser power', 'micro computed tomography', 'micro-CT']",Influence of Laser Power of Morphology and Properties of Laser-Sintered UHMWPE,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7047a15-6479-4b1f-869b-6ca77707898a/download,University of Texas at Austin,"Porous structures have unique physical properties(mechanical, density, etc.) that are related
to their low density and architecture. These properties open a wide range of potential applications,
such as biomedical, packaging, thermal insulation, filtering, food and beverage, pharmaceuticals,
automobile, military and aerospace industries [1]. Laser Sintering is an additive manufacturing
method that offers many advantages over conventional manufacturing techniques of porous
structures with well-defined architectures, controllable pore sizes, excellent reproducibility, higher
pore interconnectivities and improved mechanical properties can be produced accurately and
rapidly.
This study describes the morphological and mechanical characterisations of porous Ultra-High Molecular Weight Polyethylene (UHMWPE) laser sintered parts to gain an insight into the
correlation of process parameters and the morphological properties of these parts. Laser power was
investigated to control the mechanical properties and porosity of the structures.

The fabricated parts were characterised through porosity measurements, three point flexural
test and scanning electron microscopy (SEM). X-ray micro-computed tomography (micro-CT) was
considered to evaluate the mean internal porosity as well as the size and spatial distribution of pores
inside the structure of the UHMWPE parts aiming at a better understanding of the three-dimensional internal morphology of UHMWPE laser-sintered parts. The porosity was then
compared with the porosity measured using the helium gas pycnometer method.
The results showed a high level of porosity in the UHMWPE laser-sintered parts with a
range of 60-65% measured by micro-CT technique and helium gas pycnometer method
respectively. There are no significant differences in the results obtained from both techniques and
both results fit very well with each other. The results show that flexural strength decreases with an
increase in porosity of the sintered parts.",,,,,,
"['Yarrapareddy, Eswar R.', 'Anderson, Alan J.', 'Sears, James W.']",2020-02-12T15:25:46Z,2020-02-12T15:25:46Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79937', 'http://dx.doi.org/10.26153/tsw/6963']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Laser Processing,Influence of Laser Processing Parameters on the Corrosion Behavior in 316L Stainless Steel Laser Powder Depositions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ec0dcfb-50e3-4f79-bc4d-4a9acf087d9e/download,,,,,,,,
"['Xue, Fangkai', 'Boudaoud, Hakim', 'Robin, Guillaume', 'Cruz Sanchez, Fabio A.', 'Daya, El Mostafa']",2023-01-27T13:41:13Z,2023-01-27T13:41:13Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117329', 'http://dx.doi.org/10.26153/tsw/44210']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Fused deposition modeling (FDM)', 'Interface adhesion strength', 'Microstructure', 'Processing']",Influence of layer thickness and nozzle temperature on the interlocking adhesion strength of additive manufactured multi-material interface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59116e70-d411-4eda-9426-24ad8b12dac7/download,,"Achieving adequate adhesion strength at multi-material interfaces is always a challenge in 
material extrusion additive manufacturing (MEAM), especially when the materials have very 
different chemical affinities. This study investigated the adhesion mechanism of multi-material 
interfaces in MEAM from a micro-geometric perspective. The vertically printed interface was 
found to have a smooth surface, while the horizontally printed interface had a micro-zigzag 
interlocking geometry. The formation of this micro-zigzag interlock is due to the switching of 
extruders during printing, which mechanically reinforces the interface adhesion strength. Using 
butt-joint tensile test and microscope observation, it was found that the geometry of this zigzag 
interlock is significantly influenced by the layer thickness, nozzle temperature and extruder offset. 
By optimizing the layer thickness and nozzle temperature, the interface adhesion strength between 
dissimilar materials was increased by 58.2% without significantly increasing the printing time or 
fabrication complexity.",,,,,,
"['Norrell, J. L.', 'Kandis, .M', 'Bergman, T. L.']",2018-11-16T16:35:23Z,2018-11-16T16:35:23Z,1996,Mechanical Engineering,doi:10.15781/T2WW77K3Q,http://hdl.handle.net/2152/70297,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['powder temperatures', 'uncontrolled sintering', 'viscous sintering']",The Influence of Natural Convection and Radiation Heat Transfer on Sintering of Polycarbonate Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3213c2dd-5193-41c8-ada7-ea5f103445c0/download,,"The influence ofsurface radiation and natural convection on sintering of
polycarbonate powders processed under non-isothermal conditions is investigated. These
modes of heat transfer affect local powder temperatures and thus local sintering rates which
in turn influence part growth (uncontrolled sintering). This paper presents a 2-dimensional
sintering simulation of powder whose free surface exchanges energy with the surrounding
enclosure surfaces. Modeling is accomplished using a commercial finite element code
(FIDAP) in conjunction with a model for viscous sintering.",,,,,,
"['Kummert, C.', 'Diekmann, W.', 'Tews, K.', 'Schmid, H.J.']",2021-11-18T01:21:32Z,2021-11-18T01:21:32Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90390', 'http://dx.doi.org/10.26153/tsw/17311']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['PA6x', 'part microstructure', 'mechanical properties', 'selective laser sintering']",Influence of Part Microstructure on Mechanical Properties of PA6x Laser Sintered Specimens,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7bb58d7d-79cb-4d35-a6a9-631d0bb07eee/download,University of Texas at Austin,"The influence of different process parameters on mechanical properties of selectively laser sintered (SLS)
parts was investigated in various studies. Until now, the significant differences in mechanical characteristics
depending on processing conditions are insufficiently explained but reasons may be found in part microstructure.
For this reason, PA6x test specimens with different component properties were printed by changing laser exposure
strategies and their microstructure was examined using for example XCT-analysis. PA6x is a comparatively new
SLS material which offers outstanding mechanical properties if adequate SLS processing parameters are used. In
this study different SLS machines are used by EVONIK and the DMRC, Paderborn University to investigate the
relationship between SLS-specific manufacturing conditions, the resulting components microstructure and finally
the component properties. The knowledge gained can contribute to a deeper understanding of the process.",,,,,,
"['Jayanthi, Suresh', 'Hokuf, Bronson', 'Lawton, John']",2018-10-05T17:05:37Z,2018-10-05T17:05:37Z,1995,Mechanical Engineering,doi:10.15781/T2445HX78,http://hdl.handle.net/2152/68715,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['sterelithography models', 'photopolymer models', 'UV and thermal cure']",Influence of Post Curing Conditions on the Mechanical Properties of Stereolithographic Photopolymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eac4a606-3abb-417c-b4a6-307116271c74/download,,"Post cure methods have always been a critical issue for most of the currently used
stereolithography photopolymers. Different post cure conditions can be used to enhance the
mechanical and physical properties of the stereolithography models. To better understand the
influence of post cure conditions on these material properties, an experimental study evaluating
various post cure conditions has been conducted. Ultra-violet, thermal and ultra-sound post
curing techniques are investigated and a comparative study is made for one epoxy based
photopolymer - Somos™ 6100. Similar results should be attainable for other epoxy based
photopolymers.",,,,,,
"['Slattery, Lauren A.', 'Guckert, Nicole L.', 'Shell, Courtney E.', 'Neptune, Richard R.']",2021-10-06T20:37:38Z,2021-10-06T20:37:38Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88437', 'http://dx.doi.org/10.26153/tsw/15374']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'Nylon 11', 'material voids', 'post-build annealing', 'functional energy storage', 'prosthetic devices']",The Influence of Post-SLS-Build Annealing on Nylon 11 Material Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78fa4bc9-7c7b-4d45-a54a-94f224478194/download,University of Texas at Austin,"Functional energy storage and return prosthetic and orthotic devices have been manufactured
out of Nylon 11 using selective laser sintering due to its high ductility and energy return
properties. However, there is concern that material voids caused by incomplete sintering may
compromise material properties and lead to premature fracture. Post-build annealing has the
potential to eliminate voids caused by incomplete sintering and increase part ductility and
strength. The purpose of this study was to post-build anneal Nylon 11 tensile specimens at 1)
slightly below their melting temperature, 2) their recrystallization temperature, and 3) their glass
transition temperature for two different time durations (12 and 24 hours) to assess the
effectiveness of annealing in improving ductility and strength. Specimens annealed at their glass
transition temperature had significantly greater percent elongations and lower Young’s moduli
than specimens annealed close to their melting or recrystallization temperatures. At each
temperature, specimens annealed for shorter durations demonstrated a greater increase in percent
elongations and a greater decrease in Young’s moduli. Annealing at the glass transition
temperature for 12 hours resulted in the highest percent elongation, although it was not
significantly different from the control (unannealed) specimens. However, at these annealing
conditions Young’s modulus significantly decreased from the control specimens. Across all
annealing conditions, Young’s modulus and percent elongation were found to be negatively
correlated. Future work should focus on annealing specimens for additional combinations of
temperature and duration to further improve ductility while minimizing the negative effects on
part strength.",,,,,,
"['Gürtler, F.-J.', 'Karg, M.', 'Dobler, M.', 'Kohl, S.', 'Tzivilsky, I.', 'Schmidt, M.']",2021-10-18T21:35:54Z,2021-10-18T21:35:54Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89255,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser beam melting', 'additive manufacturing', 'metal powder bed', 'parameter optimization', 'melt pool', 'porosity formation', 'OpenFOAM']",Influence of Powder Distribution on Process Stability in Laser Beam Melting: Analysis of Melt Pool Dynamics by Numerical Simulations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5815569-349b-48fc-bd8b-3b27afd2a0d3/download,University of Texas at Austin,"The occurrence of defects in the additive manufacturing process of laser beam melting in
metal powder bed can be reduced through empiric parameter optimization – but knowledge about
basic effects like the influence of the composition of the powder layer on the melt pool is still
limited. Particle size distribution and powder layer inhomogeneity after layer coating influence
melt pool dynamics and may cause defects in the work pieces. This correlation can hardly be
analyzed in experiments, so a three-dimensional transient numerical simulation model is used.
The model is based on the continuity equation, the heat equation and the Navier-Stokes equation.
Therefore, the finite-volume method capabilities in OpenFOAM are used. The free surfaces of
the multi-phase system are calculated using the volume of fluid method. The powder beds have
unimodal or bimodal distributions without random effects in the particle composition. Their
density and thermal conductivity is adapted to reality. The investigations of the melt pool and the
porosity formation demonstrate an advantage of more and smaller particles in the powder for
compensation of defects in the powder bed, similar to the results of the experiments.",,,,,,
"['Sinico, M.', 'Cogo, G.', 'Benettoni, M.', 'Calliari, I.', 'Pepato, A.']",2021-11-18T01:01:11Z,2021-11-18T01:01:11Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90382', 'http://dx.doi.org/10.26153/tsw/17303']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['particle size distribution', 'powder particle', 'printability', 'pure copper', 'Cu', 'selective laser melting']",Influence of Powder Particle Size Distribution on the Printability of Pure Copper for Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a19bc20-f802-4332-adc9-5b79c2c54b96/download,University of Texas at Austin,"This work investigates the use of fine Cu powder, with ~ 20 vol% smaller than 15 μm size, for the
selective laser melting process. Cubes reaching > 98 % density are produced at relative low laser output
(175 W) and characterized. After the selection of a proper combination of laser scan parameters, the properties
of fabricated parts are briefly studied through profilometry and tensile tests. Finally, a voluminous demo
component for high-energy physics is manufactured to stress-test the employed SLM machine. Even though
unmolten particles and lack of fusion defects are still present in the produced specimens, the investigated
approach confirms that powder selection can have a huge influence on the processability of materials with high
reflectivity towards near-infrared irradiation.",,,,,,
"['Binder, Maximilian', 'Yücel, Olgu', 'Bareth, Thomas', 'Schlick, Georg', 'von Müller, Alexander', 'You, Jeong-Ha', 'Buschmann, Birger', 'de Luca, Riccardo', 'Fanelli, Pierlugi', 'Seidel, Christian']",2023-01-26T14:37:28Z,2023-01-26T14:37:28Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117307', 'http://dx.doi.org/10.26153/tsw/44188']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'High-Temperature Laser-based Powder Bed Fusion', 'Tungsten', 'Refractory Metal']",Influence of Powder Properties and Process Parameters on the High Temperature PBF-LB/M Manufacturability of Filigree Tungsten Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f7a2ad4-64db-42ee-956b-13a3c3cdab36/download,,"The production of complex lattice structures made of pure tungsten can be of great interest 
for potential applications in various industrial sectors such as energy technology or 
medical devices. One example is the plasma-facing armour of so-called limiter 
components in nuclear fusion power reactors, where the tungsten lattice armour is 
supposed to withstand extreme heat flux loads up-on transient plasma events.. The 
reliability of the tungsten armour is hence an important requirement for the sustainable 
operation of fusion power reactors [1,2]. 
Tungsten is difficult to process to a satisfactory degree due to its high melting point, its 
hardness as well as its susceptibility to cracking. Therefore, this paper presents the 
manner in which tungsten can be processed into fine lattice structures by means of high-
temperature laser-based powder bed fusion. It also explains to what extent the used metal 
powder and the laser-exposure strategy have an influence on pores and component 
defects. It is shown how particle size distribution and sphericity of the powders have a 
major impact on the basic processability of the material. Furthermore, it presents to what 
extent the laser exposure parameters, such as the laser hatch distance, can have an 
influence on the resulting density of the material and which methods are used to determine 
the actual material density of lattice cubes in the first place. Finally, measurements of the 
electrical conductivity of the fabricated AM structures are presented, as this is of interest 
with respect to many other areas of application.",,,,,,
"['Yamauchi, Yuki', 'Niino, Toshiki', 'Kigure, Takashi']",2021-11-04T13:48:30Z,2021-11-04T13:48:30Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89959,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['geometry', 'part quality', 'process time', 'geometry', 'laser sintering', 'low temperature']",Influence of Process Time and Geometry on Part Quality of Low Temperature Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/542e02b6-c66d-4ee9-ad99-e5d099ad3860/download,University of Texas at Austin,"The authors are developing a novel laser sintering process that prevents parts from warping
by anchoring them to a rigid base plate. Since the powder bed temperature of the process is
normally lower than in the standard process, the laser is required to supply more energy in the
novel process, namely low temperature process. Accordingly, the part quality is more sensitive to
laser parameters. Additionally, accumulation and dispersion of energy which is supplied by the
laser through layers plays an important role in the consolidation of the powder. Thus, in low
temperature process, parameter relating part geometry and time affects the part quality more than
in standard high temperature process. In this research, the influence of part size and process time
per layer on the density of parts as a primary index of part quality is investigated. Density decreases
as the process time per layer increases. With respect to part size, density increases as parts become
larger.",,,,,,
"['King, Bruce H.', 'Morissette, Sherry L.', 'Denham, Hugh', 'Cesarano, Joseph', 'Dimos, Duane']",2019-02-22T20:11:10Z,2019-02-22T20:11:10Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73473', 'http://dx.doi.org/10.26153/tsw/623']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['polymers', 'ceramics']",Influence of Rheology on Deposition Behavior of Ceramic Pastes in Direct Fabrication Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9c3c327c-fc5c-4c38-8831-0c4f20f74067/download,,"Rheology and deposition behavior offour commercially available thick-film inks and an
aqueous alumina slurry were investigated using two different slurry-based deposition systems.
The first ofthese deposition systems, a Micropen, is a commercially available system designed
for the deposition of electronic thick film circuits. The second system, referred to as a
Robocaster, is a developmental system designed to build thick or structural parts. Slurry
rheology was seen to have a minor effect on deposition behavior and the bead shape when
deposited using the Micropen. The deposition behavior was instead dominated by drying rate;
too rapid of a drying rate led to excessive clogging of the tip. Slurry rheology had a greater
impact on the shape of beads deposited using the Robocaster. Highly viscous slurries yielded
initially well-defined beads, whereas beads deposited using fluid slurries spread quickly. In both
cases, significant spreading occurred with time. These observations only held for slurries with
slow drying rates. It was observed that very fluid slurries produced well-defined beads when the
drying rate was suitably high.",,,,,,
"['Ajinjeru, Christine', 'Kishore, Vidya', 'Chen, Xun', 'Lindahl, John', 'Sudbury, Zeke', 'Hassen, Ahmed Arabi', 'Kunc, Vlastimil', 'Post, Brian', 'Love, Lonnie', 'Duty, Chad']",2021-10-27T22:06:31Z,2021-10-27T22:06:31Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89629,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['rheology', 'big area additive manufacturing', 'processing conditions', 'amorphous thermoplastics']",The Influence of Rheology on Melt Processing Conditions of Amorphous Thermoplastics for Big Area Additive Manufacturing (BAAM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e1884ec-0c5f-4740-8825-c0d19103029f/download,University of Texas at Austin,"This paper evaluates the influence of the rheological behavior of thermoplastics used in Big Area
Additive Manufacturing (BAAM) on the melt processing conditions. An extensive rheological
characterization has been conducted of two base resins; acrylonitrile butadiene styrene (ABS)
and polyphenylsulfone (PPSU) as well as their composites containing reinforcing fibers. It was
found that the unique processing conditions for each material is highly dependent on the
rheological properties of these polymeric systems. A method is presented for considering
rheological characteristics when selecting candidate materials suitable for the BAAM system and
in developing processing bounds to achieve required material properties for applications such as
high temperature tooling and composite structures.",,,,,,
"['Emminghaus, N.', 'Bernhard, R.', 'Hermsdorf, J.', 'Overmeyer, L.', 'Kaierle, S.']",2024-03-25T23:59:33Z,2024-03-25T23:59:33Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124349', 'https://doi.org/10.26153/tsw/50957']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturinng', 'Ti-6Al-4V', 'laser powder bed fusion', 'silane', 'powder recycling']",Influence of Silane-doped Argon Processing Atmosphere on Powder Recycling and Part Properties in L-PBF of Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1babedd3-a973-4f2f-a1be-e74b80073d34/download,University of Texas at Austin,"In the additive manufacturing of metal powders, the residual oxygen in the processing atmosphere plays
a crucial role, especially in highly reactive materials like titanium alloys. Besides oxidation of the built parts, it
leads to oxygen pick-up into the unmolten powder. Since oxidized particles cannot be removed during
recycling, the powder properties deteriorate after multiple uses. In this work, Ti-6Al-4V powder was
processed under conventional argon atmosphere (residual oxygen content < 0.01 vol%) as well as silane-doped
argon atmosphere (< 0.001 vol% silane in argon). The silane-doping leads to a residual oxygen content of <
10-20
 vol%. The powder was sieved and used 5 times for each atmosphere. The powder properties morphology,
chemical composition and flowability were analyzed for virgin as well as reused powder. Furthermore, the
roughness and relative density of the built parts were evaluated. It was hypothesized that oxygen-free
production improves recyclability and thus resource efficiency.",,,,,,
"['Kelley, J.P.', 'Newkirk, J.W.', 'Bartlett, L.N.', 'Sparks, T.', 'Isanaka, S.P.', 'Alipour, S.', 'Liou, F.']",2024-03-26T00:02:23Z,2024-03-26T00:02:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124350', 'https://doi.org/10.26153/tsw/50958']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser-dirrected energy deposition', 'alloy design', 'robustness', 'sensitivity analysis', 'high-strength low-alloy steel', 'in-situ alloying', 'powder blend']",INFLUENCE OF STEEL ALLOY COMPOSITION ON THE PROCESS ROBUSTNESS OF AS-BUILT HARDNESS IN LASER-DIRECTED ENERGY DEPOSITION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e183dbc-1993-45cd-b4f1-ddfd185c298d/download,University of Texas at Austin,"To ensure consistent quality of additively manufactured parts, it is advantageous to identify
alloys which can meet performance criteria while being robust to process variations. Toward such
an end, this work studied the effect of steel alloy composition on the process robustness of as-built
hardness in laser-directed energy deposition (L-DED). In-situ blending of ultra-high-strength lowalloy steel (UHSLA) and pure iron powders produced 10 alloys containing 10-100% UHSLA by
mass. Thin-wall samples were deposited, and the hardness sensitivity of each alloy was evaluated
with respect to laser power and interlayer delay time. The sensitivity peaked at 40-50% UHSLA,
corresponding to phase fluctuations between lath martensite and upper bainite depending on the
cooling rate. Lower (10-20%) or higher (70-100%) alloy contents transformed primarily to ferrite
or martensite, respectively, with auto-tempering of martensite at lower cooling rates. By avoiding
martensite/bainite fluctuations, the robustness was improved.",,,,,,
"['Rietzel, D.', 'Drexler, M.', 'Kühnlein, F.', 'Drummer, D.']",2021-10-04T21:31:05Z,2021-10-04T21:31:05Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88354', 'http://dx.doi.org/10.26153/tsw/15293']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['powder based additive manufacturing', 'beam based additive manufacturing', 'laser sintering', 'mask sintering', 'influencing paramters', 'part properties']",Influence of Temperature Fields on the Processing of Polymer Powders by Means of Laser and Mask Sintering Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2910f4c-7224-49a5-b30a-b434f6533a6c/download,University of Texas at Austin,"Besides their high potential for individual series-production, powder and beam based additive manufacturing
technologies, like laser and mask sintering, are in general still restricted to prototyping applications. This is a
result of multiple limitations concerning part properties (e.g. mechanical and geometrical), their insufficient
reproducibility due to transient thermal conditions and the limited range of available materials. The main focal
point of this paper is to show the influencing parameters (e.g. temperature fields in the building chamber) of
powder-based thermoplastic processing technologies on part properties, like porosity and surface quality, and
on the processability of further new polymers (e.g. polypropylene and polyoxymethylene).",,,,,,
"['Huseynov, Orkhan', 'Fidan, Ismail']",2023-01-20T16:53:56Z,2023-01-20T16:53:56Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117266', 'http://dx.doi.org/10.26153/tsw/44147']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Fiber Reinforced Additive Manufacturing', 'Short Carbon Fiber', 'Fused Filament  Fabrication', 'Thermal Properties', 'Thermal Characterization']",Influence of the Different Matrix Materials on the Thermal Properties of Short Carbon Fiber Reinforced Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e26cade-4c20-42d4-9f52-6c7236b07121/download,,"A considerable amount of literature has been published on the thermal properties of the 
short carbon fiber reinforced composites (SCFRC). However, no study has focused on the effect 
of the various matrix materials on the thermal properties of the SCFRC. The aim of this study is 
to investigate the thermal propertiesof neat and composite PETG, PC/PBT, ABS, and Nylon filled 
with short carbon fibers. In order to do this, thermal conductivity and thermal diffusivity of the 
samples were measured. Thermogravimetric and differential scanning calorimetry analyses were 
performed to study degradation, glass transition temperature, and specific heat value. The findings 
of the study are essential in reporting the relationships between the SCFRCs and commonly used 
polymer materials.",,,,,,
"['Spierings, A.B.', 'Herres, N.', 'Levy, G.']",2021-09-30T15:36:34Z,2021-09-30T15:36:34Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88265', 'http://dx.doi.org/10.26153/tsw/15206']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'selective laser melting', 'surface quality', 'powder materials']",Influence of the Particle Size Distribution on Surface Quality and Mechanical Properties in Additive Manufactured Stainless Steel Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b78555b-63e0-4b0b-ae00-5686cf20c3a1/download,University of Texas at Austin,"A recent study confirmed that the particle size distribution of a metallic powder material has a
major influence on the density of a part produced by SLM. Although it is possible to get high
density values with different powder types, the processing parameters have to be adjusted
accordingly, affecting the process productivity. However, the particle size distribution does not only
affect the density but also the surface quality and the mechanical properties of the parts. Therefore,
this study compares three different particle size distributions depending on the laser scan velocity
and two layer thicknesses of 30μm and 45μm. By using an optimized powder material a low surface
roughness can be obtained. A subsequent blasting process can further improve the surface
roughness for all powder materials used in this study although this does not change the ranking of
the powders with respect to the resulting surface quality.",,,,,,
"['Meyer, L.', 'Wegner, A.', 'Witt, G.']",2021-11-04T13:32:54Z,2021-11-04T13:32:54Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89954,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'packing density', 'translation', 'contra-rotating coating', 'ratio']",Influence of the Ratio Between the Translation and Contra-Rotating Coating Mechanism on Different Laser Sintering Materials and Their Packing Density,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24321868-a543-4f9b-a942-76dd4569a480/download,University of Texas at Austin,"An initial study about the advanced machine parameters and their impact on the packing density
of different laser sintering materials was conducted on a self-developed laser sintering machine.
Usually, on commercial machines, the ratio between the translational and contra-rotatory
movement of the roller is fixed. The standard ratio is established for polyamide 12, but new
materials, such as polyamide 6 or polybutylene terephthalate, need adjustable parameters to find
optimized composition coating results. In the testing machine, the contra rotating roller can be
replaced by a coating blade to generate the powder layers. In Addition to the tests with the roller,
two different shapes of coating blades were tested. This allows a comparison between both
commercial coating systems in laser sintering machines.",,,,,,
"['Lubkowitz, V.', 'Scherer, T.', 'Schulze, V.', 'Zanger, F.']",2024-03-26T05:39:27Z,2024-03-26T05:39:27Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124359', 'https://doi.org/10.26153/tsw/50967']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['AlSi10Mg', 'TiC nanoparticles', 'laser power bed fusion', 'additive manufacturing']",Influence of TiC-Nanoparticles on the material properties of AlSi10Mg manufactured by Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/29795b4c-3824-48ff-b223-b66c467514d3/download,University of Texas at Austin,"Additive manufacturing enables the production of complex lightweight components.
However, the poor use of atomized metal powders poses a challenge in terms of ensuring
flowability and new high-strength aluminum alloys are still lacking. Some investigations show that
the mechanical properties of AlSi10Mg can be improved by adding TiC nanoparticles. This study
aims to determine if the influence of small amounts of TiC additions, which are normally used to
improve the flowability of fine powders, is also sufficient to improve the mechanical properties. It
was found that the addition of 0.46 wt% TiC-Nanoparticles with a size of 50 nm led to a
homogeneous grain size distribution and an increase of 16 % in yield strength, but a 32 % decrease
in elongation compared to pure AlSi10Mg. Further, a strong median grain size reduction from 5.08
to 2.74 µm could be observed by adding 0.96 wt% of TiC-Nanoparticles.",,,,,,
"['Gu, Hengfeng', 'Gong, Haijun', 'Pal, Deepankar', 'Rafi, Khalid', 'Starr, Thomas', 'Stucker, Brent']",2021-10-11T20:40:39Z,2021-10-11T20:40:39Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88638', 'http://dx.doi.org/10.26153/tsw/15572']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['energy density', 'metal selective laser melting', 'selective laser melting', '17-4PH stainless steel', 'porosity', 'microstructure']",Influences of Energy Density on Porosity and Microstructure of Selective Laser Melted 17- 4PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac003b41-d9c3-49bb-bb4a-0c9e888c54f5/download,University of Texas at Austin,"Energy density, which directly impacts the properties of as-built parts, is a key factor in the metal
selective laser melting (SLM) process. This paper studies the influences of energy density on
porosity and microstructure of SLM 17-4PH stainless steel parts. Experiments were carried out by
varying processing parameters to change energy density. Porosity was estimated using the
Archimedes method and image analysis. Microstructures were investigated through optical and
electron microscopy. The experimental results were discussed regarding porosity formation and
microstructure characterization.",,,,,,
"['Momenzadeh, Niknam', 'Berfield, Thomas A.']",2021-11-11T15:58:20Z,2021-11-11T15:58:20Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90226', 'http://dx.doi.org/10.26153/tsw/17147']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['polyvinylidene fluoride', 'piezoelectric properties', 'fourier transform infrared spectroscopy', 'fused filament fabrication']",Influences of Printing Parameters on Semi-Crystalline Microstructure of Fused Filament Fabrication Polyvinylidene Fluoride (PVDF) Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2088947-d06b-4a5b-baa9-804f5f345c39/download,University of Texas at Austin,"Piezoelectric polymers have garnered wide interest for sensing, actuation, and energy harvesting
applications due to their unique combination of high strain tolerance and electro-mechanical coupling. Compared
to other piezoelectric polymers, polyvinylidene fluoride (PVDF) and its copolymer and terpolymer variations
demonstrate some of the strongest piezoelectric responses. One of the primary challenges associated with PVDF
is that its piezoelectric response is highly dependent on its microstructure, which varies greatly with
manufacturing-associated stresses. This work investigates Fused Filament Fabrication (FFF) of PVDF polymers,
and the effects of processing parameters such as layer thickness, infill pattern, infill density and nozzle diameter
on its microstructure development. Fourier Transform Infrared Spectroscopy (FTIR) measurements are used to
assess the relative phase content of the semi-crystalline microstructure arrangement primary related with
significant piezoelectric response in PVDF (β-phase).",,,,,,
"['Steinberger, J.', 'Shen, J.', 'Göpfert, J.', 'Gerner, R.', 'Daiber, F.', 'Manetsberger, K.', 'Fersti, S.']",2019-09-23T16:11:58Z,2019-09-23T16:11:58Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75952', 'http://dx.doi.org/10.26153/tsw/3051']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Inhomogeneous,Inhomogeneous Shrinkage of Polymer Materials in Selective Laser Sintering 298,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b728122-aea4-49a9-ac62-197091515cd7/download,,"It is well known that the laser beam of an SLS machine can be controlled almost exactly. The inaccuracy of the mechanical movements of the machines is also much lower than the actual errors of the SLS parts. How can we explain this discrepancy? One answer is the temperature inhomogeneity in the build field and in the part bed. In this article the effect of temperature dependent volume relaxation of pre-sintered polymer parts on the inaccuracy of the SLS process will be discussed. The investigation shows that it depends on the temperature, pressure and time. Measurements of the temperature distribution in an SLS part bed were carried out. By determining coordinate-dependent scaling factors, an empirical method to compensate this nonlinear shrinkage is presented in this article.",,,,,,
"['Barrow, Stacia L.', 'Bourell, David', 'Evajs, Scott']",2020-02-13T19:14:39Z,2020-02-13T19:14:39Z,8/16/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79962', 'http://dx.doi.org/10.26153/tsw/6987']",eng,2004 International Solid Freeform Fabrication Symposium,Open,High-temperature infiltration,An Initial Assessment of Infiltration Material Selection for Selective Laser Sintered Preforms,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d189726b-4814-425a-8568-4535c8a392d3/download,,"High-temperature infiltration is an important process that is used to add strength to skeletal
microstructures. In this study, particulate metal matrix composites (MMCs) are fabricated.
MMCs are applied in a wide variety of industries, including military, aircraft, tooling and
automotive. In this paper, various materials for infiltrating selective laser sintered (SLS) silicon
carbide and titanium carbide preforms are considered based on fundamental knowledge of SLS
and infiltration mechanics. Proposed infiltrant materials systems include an aluminum-silicon
alloy infiltrant and a silicon carbide preform, ductile iron infiltrated into a titanium carbide
preform, and commercially pure silicon infiltrated into a silicon carbide preform. The first two
infiltrants are considered because they add ductility to the brittle silicon carbide or titanium
carbide part, thus broadening the range of applications. They also will model a broader field of
possible infiltrants, including magnesium and iron-based materials, (e.g., steel). Silicon is
investigated because it adds strength to silicon carbide, is robust at high temperatures, and has a
comparable coefficient of thermal expansion. Presented is a feasibility assessment of these
systems based on infiltration theory.",,,,,,
"['Collins, Daniel S.', 'Turner, Cameron']",2021-12-07T17:20:27Z,2021-12-07T17:20:27Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90727', 'http://dx.doi.org/10.26153/tsw/17646']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['print heating', 'radiative heat transfer', 'fused deposition modeling', 'Arizona State University']",Initial Development of a Simulation Model of a Radiation-based Print Heating System for Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/302ad41e-a084-47f6-a1e4-ba190ead60b2/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) has become a standard 3D printing process for
thermoplastics. However, the process results in different strength characteristics along each
cardinal direction of a part attributed to different bonding times between filaments. The resulting
anisotropic characteristics are an obstacle when considering FDM printed parts for mechanical
purposes. Work at Arizona State University has demonstrated a method using laser-based heating
to achieve improved polymer bonding without loss of dimensional accuracy. In this research we
consider the possibilities of reheating the filament via radiative heat transfer to achieve the same
outcome. By exploring the approach in simulation and conducting confirmation experiments, we
evaluate the ability to increase strength in FDM components by post-deposition controlled
radiative heat-transfer.",,,,,,
"['Lewis, Adam', 'McElroy, Austin', 'Milner, Thomas', 'Fish, Scott', 'Beaman, Joseph']",2021-11-03T22:05:47Z,2021-11-03T22:05:47Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89947,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['optical coherence tomography', 'part porosity', 'selective laser sintering', 'laser power']",Initial Investigation of Selective Laser Sintering Laser Power vs Part Porosity Using In-Situ Optical Coherence Tomography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/36048083-89b3-4de3-b2de-679c9783a34c/download,University of Texas at Austin,"Additional types of process sensors could be useful in further improving consistency of
Selectively Laser Sintered (SLS) parts. Optical Coherence Tomography (OCT) has shown
promise as a new SLS process sensor which can yield depth resolved data not attainable with
conventional sensors. This study investigates the use of OCT as a tool to determine part
porosity. Various laser powers were used during the build and the in-situ OCT data
corresponding to the various laser powers are compared. The finished part was then imaged
using X-ray Computed Tomography (XCT). Porosity data was obtained and is compared with
the OCT data.",,,,,,
"['Karapatis, N. P.', 'Griethuysen, J.-P. S. van', 'Glardon, R.']",2018-11-30T16:53:42Z,2018-11-30T16:53:42Z,1997,Mechanical Engineering,doi:10.15781/T26D5PX29,http://hdl.handle.net/2152/70599,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', '3D Systems']",Injection Molds Behavior and Lifetime Characterization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/047e4d6c-3fee-43f8-bf22-535c8a0a19cd/download,,"This paper presents the concept of a standard method used to determine the durability of
injection molds. In particular, some Rapid Tooling molds are less resistant to abrasive plastics than
conventional steel molds. Some evidence of wear in a conventional mold is given, and a specific
mold is designed for this test; polymer materials are defined and the test methodology is outlined.
Numerical simulation is utilized to show the areas ofthe mold subject to high shear stresses.",,,,,,
"['Miers, John C.', 'Zhou, Wenchao']",2021-10-21T18:18:34Z,2021-10-21T18:18:34Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89417,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['inkjet printing', 'megahertz frequency', 'droplet formation']",Inkjet Printing at Megahertz Frequency,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8d75d85-3930-4650-9c16-f7c237bcebc0/download,University of Texas at Austin,"Inkjet printing enables more efficient, economic, scalable manufacturing for a wider variety of
materials, than other traditional additive techniques. However, the jetting frequency of commercial
droplet-on-demand inkjet techniques is mostly limited to ~10 kHz. This paper presents an
investigation of the possibility of jetting at megahertz frequencies in order to boost the productivity
of inkjet by ~100 times. The key to this problem is rooted in droplet formation dynamics, a subject
that has been extensively studied for over 300 years. Hence, the focus of this paper is to understand
the limitations of generating droplets at a megahertz frequency and explore possible solutions for
overcoming these limitations. The paper begins with a review of literature on the dynamics of
droplet formation. A numerical model is then developed for the simulation of droplet formation
dynamics. The numerical model is validated against available experimental data from the
literature. Aided by insights gained from scaling analysis, the validated model is then used to study
the effects of different process parameters on high frequency jetting. The study finds energy
density input to the nozzle is the key to achieve megahertz frequency printing.",,,,,,
"['Kolb, Cara G.', 'Mareddy, Harish R.', 'Guenter, Florian J.', 'Zaeh, Michael F.']",2021-11-16T16:39:56Z,2021-11-16T16:39:56Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90340', 'http://dx.doi.org/10.26153/tsw/17261']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['inkjet printing', 'lithium-ion cell', 'multi-material processing', 'surface structuring']",Inkjet Printing of Geometrically Optimized Electrodes for Lithium-Ion Cells: A Concept for a Hybrid Process Chain,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bdeed7ed-2640-4516-bbff-bc32ac2f393b/download,University of Texas at Austin,"Lithium-ion batteries have proven to be reliable energy storage devices for portable and
stationary electrical consumers because they possess a high energy and power density.
Nevertheless, modern applications require more demanding performance characteristics.
Electrodes with a structured surface design, which improves current densities and therefore
enables faster charging and discharging, promise to reach the required cell characteristics.
Conventionally, structured electrodes are produced by subtractive post-treatment, such as laser
processing, which only allows structures of limited complexity. This paper demonstrates a novel
approach using inkjet printing to produce electrodes with interlocked structures of high
geometrical complexity. A concept for a hybrid process chain that combines the additive process
with subtractive and further manufacturing technologies is presented. In addition, a selection of
geometrically optimized electrodes is shown. This hybrid process chain has the potential to create
functional electrodes by multi-material processing of liquid and powdery raw materials.",,,,,,
"['Begines, B.', 'Hook, A.L.', 'Wildman, R.D.', 'Tuck, C.J.', 'Alexander, M.R.']",2021-10-21T20:54:54Z,2021-10-21T20:54:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89445,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['bacterial resistance', 'bacterial attachment', 'inkjet printing', 'printability', 'medical devices', 'bacterial infections']",Inkjet Printing of Materials with Resistance to Bacterial Attachment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/39f23b65-7f62-4bab-a69a-14e5d4abee0b/download,University of Texas at Austin,"Biofilm formation on the surface of medical devices is a major source of health-care
associated infections. The discovery of new materials that inherently avoid formation of such
biofilms on their surface points the way to the fabrication of biofilm resistant devices, with
the consequent reduction in the incidence rate of device centred infections and therefore a
reduction in suffering and costs for health-care systems. Drop on Demand (DOD) Three
Dimensional (3D) Inkjet Printing presents higher versatility than common techniques for
printing biomaterials. One of the main representations of this enhanced versatility is
polymerisation post-jetting, which provides a great range of printable polymers. The
combination of such materials with inkjet printing could revolutionise the biomedical
industry.
In this paper, the printability of four acrylates with resistance to bacterial attachment
was assessed using the printability indicator or Z parameter. Three of the materials showed a
value of Z within the printability range. The remainder displayed a Z value higher than the
maximum suggested. However, this material was ejected with stability using a complex
waveform designed for low viscosity inks. Drop spacing was optimised for each ink using
PET and glass as substrates. The combination of printability optimisation together with ideal
drop spacing allowed the construction of 3D structures of three of the four inks that were
tested.",,,,,,
"['Kuhn, Joshua', 'Green, Matthew', 'Bashyam, Sanjai', 'Seepersad, Carolyn Conner']",2021-10-19T15:21:39Z,2021-10-19T15:21:39Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89297,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'design for 3D printing', 'automatic part removal system']",The Innovation Station: A 3D Printing Vending Machine for UT Austin Students,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8b6d924f-1647-4ec4-9ebe-12929c1f996c/download,University of Texas at Austin,"The Innovation Station is designed to provide on-demand, web-enabled 3D printing
securely in a public space. The overarching goal is to lower the barriers to 3D printing at a
university, to facilitate innovation and creativity, and to inspire future engineers. Both hardware
and software innovations were required to realize this capability. From the hardware side, we
invented a process to automatically remove parts from the 3D printer and sweep them into a bin
from which users can retrieve them without directly accessing the 3D printer. From the software
side, in partnership with the Faculty Innovation Center (FIC) at UT Austin, we created a web
portal that allows students to upload parts remotely and access detailed directions for creating
parts. It also allows administrators to remotely manage the queue and initiate builds. Together,
the hardware and the software innovations enable printing multiple jobs continuously without
user intervention and remote cancellation of jobs. Plans for the entire station, both hardware and
software, are intended to be open source, with a startup cost of less than $4,000 for recreating the
station at a new location.",,,,,,
"['Lin, Feng', 'Zhang, Lei', 'Zhang, Ting', 'Wang, Jia', 'Zhang, Renji']",2021-10-05T15:32:43Z,2021-10-05T15:32:43Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88392', 'http://dx.doi.org/10.26153/tsw/15331']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'rapid prototyping manufacturing', 'solid freeform fabrication', 'innovative education']",Innovative Education in Additive Manufacturing in China,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8e63641-0ab6-4770-853a-e77fd890528f/download,University of Texas at Austin,"Beginning in 1992, China began to conduct research on additive manufacturing (AM) (i.e.,
rapid prototyping manufacturing or solid freeform fabrication). These studies included three main
areas: processes, equipment, and applications in different fields. At the same time, various
educational initiatives in AM were also begun.
Regarding the first area, a number of courses related to AM are now being offered in
universities and colleges, and not just in those that have already developed research programs on
AM, such as Tsinghua University, Xi'an Jiaotong University, Huazhong University of Science
and Technology, and South China University of Technology, as well as some higher vocational
schools. Owing to the orientation of these colleges and schools, their focus tends to be on the
practical applicability of the courses they offer.
In addition to the lectures they offer, all of these universities and colleges are equipped with
a laboratory or resources for experiments, and have brought in equipment on which students can
practice operating software (3D CAD. etc.) and make prototypes of their own design. Along with
the development of AM research in China, the proportion of equipment in Chinese production is
increasing as well. Moreover, these courses offer lectures, employ Ph.D. students as teaching
assistants for undergraduate or junior college students, and also offer training related to creative
design and manufacturing for postgraduates. This training has produced good results, in that it
requires postgraduates to combine what they have learnt during lectures with their own research.
In addition, associations and companies have played an important role in the development of
AM in China by interacting with society and offering a number of seminars and workshops.
There are many companies that offer courses for people with specific interests, and courses for
engineers and technicians have created a boom in AM in China’s automobile industry. A number
of associations and companies have even jointly organized design competitions in vocational
schools. When students participate in these competitions they become familiar with the advanced
technology of AM, an experience that is very important for their future work.",,,,,,
"['Almeida, P.M. Sequeira', 'Williams, S.']",2021-09-29T22:31:37Z,2021-09-29T22:31:37Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88221', 'http://dx.doi.org/10.26153/tsw/15162']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Wire + Arc Additive Layer Manufacture (WAALM)', 'Additive Layer Manufacturing (ALM)', 'Cold Metal Transfer (CMT)', 'Ti-6Al-4V', 'Systematic Experimental Approach (SEA)', 'high deposition rate', 'Buy-to-Fly']",Innovative Process Model of Ti-6Al-4V Additive Layer Manufacturing Using Cold Metal Transfer (CMT),Conference paper,https://repositories.lib.utexas.edu//bitstreams/8173734a-71ee-4c28-aa8e-a7cc2635a51c/download,University of Texas at Austin,"New approaches to modern manufacture have emerged from Additive Layer Manufacturing
(ALM) technologies over the last 25 years. These approaches provide form, fit and function to
a wide range of metallic alloys and components. Wire + Arc Additive Layer Manufacture
(WAALM) has gained the interest of the research community in recent years due to its high
deposition rate and efficiency (100%). The technique has been presented to the aerospace
manufacturing industry as a unique low cost solution for large structural components
manufacture. With this process product development time, capital investment and “Buy-to-Fly” ratios can be significantly improved. One of the greatest challenges of WAALM systems
is the control algorithms needed to predict optimum welding parameters in order to achieve a
specific target wall width/height requirement, and maximum deposition efficiency. This paper
describes a process model for multilayer Ti-6Al-4V deposition using the Gas Metal Arc
Welding based process of Cold Metal Transfer. The process model is based on a Systematic
Experimental Approach carried out using a regression analysis. The mathematical
relationships obtained are ready to use in future large scale “intelligent” WAALM controllers.",,,,,,
"['Koo, J. H.', 'Pilato, L.', 'Wissler, G.', 'Cheng, J.', 'Ho, W.', 'Nguyen, K.', 'Lao, S.', 'Cummings, A.', 'Ervin, M.']",2020-02-20T20:12:35Z,2020-02-20T20:12:35Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80048,eng,2005 International Solid Freeform Fabrication Symposium,Open,rapid manufacturing,Innovative Selective Laser Sintering Rapid Manufacturing using Nanotechnology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e07b8363-e24a-4243-a974-289b4ae9f648/download,,"The objective of this research is to develop an improved nylon 11 (polyamide 11) polymer
with enhanced flame retardancy, thermal, and mechanical properties for selective laser sintering
(SLS) rapid manufacturing (RM). A nanophase was introduced into nylon 11 via twin screw
extrusion to provide improved material properties of the polymer blends. Atofina (now known
as Arkema) RILSAN® nylon 11 injection molding polymer pellets was used with three types of
nanoparticles: chemically modified montmorillonite (MMT) organoclays, nanosilica, and carbon
nanofibers (CNF) to create nylon 11 nanocomposites. Wide angle X-ray diffraction (WAXD)
and transmission electron microscopy (TEM) were used to determine the degree of dispersion.
Fifteen nylon 11 nanocomposites and control nylon 11 were fabricated by injection molding.
Flammability properties (using a cone calorimeter with a radiant flux of 50 kW/m2
) and
mechanical properties such as tensile strength and modulus, flexural modulus, elongation at
break were determined for the nylon 11 nanocomposites and compared with the baseline nylon
11. Based on flammability and mechanical material performance, five polymers including four
nylon 11 nanocomposites and a control nylon 11 were cryogenically ground into fine powders
for SLS RM. SLS specimens were fabricated for flammability, mechanical, and thermal
properties characterization. Nylon 11-CNF nanocomposites exhibited the best overall properties
for this study.",,,,,,
"['Plant, R.', 'Chang, S.', 'Hague, R.', 'Tuck, C.', 'Wildman, R.']",2023-04-05T13:36:57Z,2023-04-05T13:36:57Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117771', 'http://dx.doi.org/10.26153/tsw/44650']",eng,2022 International Solid Freeform Fabrication Symposium,Open,packaging,Inserting Components into Geometries Constructed onto a Non-Standard Substrate for Electronics Packaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cdc9381a-74a4-46ce-b8d3-6549138e9233/download,,"Additive manufacturing (AM) has matured from its initial concept as a prototyping technique to an 
industrial manufacturing process.  Consequently, AM processes must meet relevant standards for 
an increasing number of applications. Here, we investigate inserting components into geometries 
constructed onto a silicon nitride substrate, using stereolithography (SLA), for the purpose of 
electronics packaging.  Compared to conventional processes, SLA avoids high temperatures and 
stresses while permitting much greater flexibility to arrange components in three dimensions.  This 
facilitates an increased feature density and the construction of packages for use in complex spaces. 
A characteristic of interest to this application, is the SLA material-substrate interaction and the 
resulting quality of adhesion. The adhesion mechanism between SLA and silicon nitride is 
investigated and substantially enhanced by a pre-treatment process.  A process for then inserting 
large and complex geometries and components into the SLA build process is identified and 
compliance of the product with relevant standards is reviewed.",,,,,,
"['Jameekornkul, P.', 'Wang, J.', 'Panesar, A.']",2023-04-05T17:17:19Z,2023-04-05T17:17:19Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117782', 'http://dx.doi.org/10.26153/tsw/44661']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Schwarz-P Lattices,Insight into Compressive Behaviour of Schwarz-P Lattices Fabricated by Material Extrusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3fd3b1b9-70b0-4888-af1c-2ace1428cd9b/download,,"Lattice structures are increasingly being chosen for lightweight applications due to their high strength-
to-weight ratio and energy absorption capability. This work investigates the mechanical performance of the 
Schwarz-Primitive (SP) lattices with a range of unit-cell sizes and relative densities. The SP lattices were 
fabricated using material extrusion with ASA (industrial grade) and ABS material, then tested along different 
orientations to build direction. Digital Image Correlation (DIC) was utilised to measure the local strain and 
deformation mechanism. The preliminary results indicate that stiffness and strength were related to densities 
abiding the Ashby-Gibson model in well-controlled tight bands, which will help inform design decisions 
for future adoption. Further experiments will be conducted to extend the finding of this study, gain a better 
understanding of graded lattices and provide insights on the potential use of fibre reinforcement in lattices.",,,,,,
"['Brown, Stephen W.', 'Przyjemski, Andrew G.', 'McPherson, Matthew B.', 'Steinberg, Jacob H.', 'Corbin, David', 'Reutzel, Edward W.']",2021-11-15T21:19:12Z,2021-11-15T21:19:12Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90276', 'http://dx.doi.org/10.26153/tsw/17197']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['powder flow', 'deviations', 'directed energy distribution', 'additive manufacturing']",Insights into Powder Flow Characterization Methods for Directed Energy Distribution Additive Manufacturing Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5aa7e094-24d5-40b8-bb3f-1f5a4172b14d/download,University of Texas at Austin,"Powder-blown Directed Energy Distribution Additive Manufacturing systems often feed
powdered metal into a melt pool generated by a laser. As the laser is moved, the melt pool
solidifies, leaving behind a deposit. Such depositions may be built up into full components or used
to add features on existing components. Distribution and uniformity of the powder flow is critical
to achieve uniform and predictable depositions. For example, small deviations at the minute-level
(cf. the resolution limit of the deposition) can propagate to gross deviations at the component-level. Meanwhile, large deviations in the powder flow can be yet unobservable to the naked eye,
but produce catastrophic effects within small depositions. Such depositions are common to repair
applications targeted at ARL Penn State, wherein relatively small deposits are created on larger,
critical components. Novel and re-purposed OEM tools are compared to study these powder flow
behaviors, providing new insights into process variability.",,,,,,
"['Mijares, Jonathan', 'Mireles, Jorge', 'Gaytan, Sara M.', 'Espalin, David', 'Carter, William T.', 'Wicker, Ryan B.']",2021-10-12T22:10:41Z,2021-10-12T22:10:41Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88751', 'http://dx.doi.org/10.26153/tsw/15685']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['multi-wavelength pyrometer', 'temperature monitoring', 'Electron Beam Melting', 'installation', 'thermal feedback']",Installation and Thermal Feedback from a Multi-wavelength Pyrometer in Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/84eb1a6d-50ac-4de5-99c3-2c06de321f10/download,University of Texas at Austin,"The purpose of this paper is to outline and discuss the installation and use of a multi-wavelength
pyrometer for process temperature monitoring in Electron Beam Melting (EBM). A multi-wavelength
pyrometer was externally mounted atop an EBM system to observe and record surface temperatures
during the fabrication process. The multi-wavelength pyrometer is a non-contact device capable of
measuring the temperature of an object without the need of knowing the object’s emissivity. Temperature
data from the EBM system thermocouple and the multi-wavelength pyrometer were compared, and it was
determined that the pyrometer measurements were reasonable. During fabrication, the multi-wavelength
pyrometer allowed the characterization of the EBM process that consisted of various steps during
fabrication (e.g. heating of the build platform, powder deposition, and melting). Measurement of surface
temperatures during fabrication can be useful for parameter development of novel materials, prediction of
resulting microstructural architectures, and ultimately as feedback used in a closed-loop control system,
allowing full spatial and temporal control of melting and microstructure.",,,,,,
"['Shimek, M.', 'Lappo, K.', 'Wood, K.', 'Bourell, D.', 'Crawford, R.']",2019-11-21T18:15:13Z,2019-11-21T18:15:13Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78553', 'http://dx.doi.org/10.26153/tsw/5609']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Prototypes,Instrumented Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/05904cef-72fd-4ba4-b78e-4d2acf14227b/download,,"Full scale prototyping can be expensive and time consuming. Virtual prototypes
reduce costs and time but often cannot be relied on for full scale production.
Instrumented SFF prototypes update virtual prototypes, reducing cycle times and costs
for full scale production. Both single and multi-layer access, two different methods for
embedding sensors, are investigated at the University of Texas at Austin. Sensors are
first embedded in a simulated SLS process to determine if embedding off the shelf
sensors is feasible. Foil strain gages are then embedded into cantilever beams using
multi-layer techniques. Both foil strain gages and bead type thermocouples are also
embedded using single layer techniques. The results of the single layer tests will be used
to construct a proof-of-concept prototype for single layer embedding.",,,,,,
"['Pal, Deepankar', 'Patil, Nachiket', 'Nikoukar, Mohammad', 'Zeng, Kai', 'Haludeen Kutty, Khalid', 'Stucker, Brent E.']",2021-10-07T15:13:44Z,2021-10-07T15:13:44Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88474', 'http://dx.doi.org/10.26153/tsw/15410']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['in-situ process monitoring', 'finite element modeling', '3D dislocation density based', 'thermo-mechanical', 'post-process microscopy', 'mechanical testing', 'Additive Manufacturing', 'modeling software']","An Integrated Approach to Cyber-Enabled Additive Manufacturing using Physics based, Coupled Multi-scale Process Modeling",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c74cec12-34ee-42c9-b0aa-49207de18ece/download,University of Texas at Austin,"The complexity of localized and dynamic boundary conditions in additive manufacturing
processes makes it difficult to track in-situ thermo-mechanical changes at different length scales
within a part using experimental equipment such as a FLIR1 system and other NDE2 techniques.
Moreover, in-situ process monitoring is limited to providing information at an exposed surface of
the build. As a result, an understanding of the bulk microstructure and behavior of a part still
requires rigorous post-process microscopy and mechanical testing.
In order to circumvent the limited feedback obtained from in-situ experiments and to better
understand material response, a novel 3D dislocation density based thermo-mechanical finite
element framework has been developed. This framework solves for the in-situ response 2 orders
of magnitude faster than currently used state-of-the-art modeling software since it has been
specifically designed for additive manufacturing platforms. Various aspects of this simulation tool
have been and are being validated using research grants from NSF3, ONR4, AFRL5, NIST6 and NAMII7.
This modeling activity has many potential commercial impacts, such as to predict the
anisotropic performance of AM-produced components before they are built and as a method to
enable in-situ closed-loop process control by monitoring the process and comparing it to predicted
responses in real time (as the model will be used to predict results faster than an AM machine can
build a part). This manuscript provides an overview of various software modules essential for
creation of a robust and reliable AM software suite to address future needs for machine
development, material (alloy) development and geometric optimization.",,,,,,
"['Stucker, Brent', 'Qu, Xiuzhi']",2019-10-30T16:39:40Z,2019-10-30T16:39:40Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78189', 'http://dx.doi.org/10.26153/tsw/5278']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Finish Machining,An Integrated Approach to Finish Machining of RP Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c166bd5e-7a8d-4522-bf14-3693371714f7/download,,"An integrated approach to finish machining of RP parts and tools has been
developed at the University of Rhode Island. Pre-processing operations, including surface
offsets to add machining stock, and post-processing operations, including CNC tool-path
generation, have been combined into one integrated set of software algorithms to make
possible the effective finishing of near-net parts and tools from RP. An in-depth
description of the uniquely developed STL vertex offset algorithm will be explored as
well as an automatic method for adaptive raster milling, sharp edge contour machining
and hole drilling from STL files. The time involved and surface finish benefits of the
developed methodology will be compared to alternative approaches.",,,,,,
"['Mahesh, M.', 'Loh, H.T.', 'Wong, Y.S.', 'Fuh, J.Y.H.']",2019-11-20T16:08:23Z,2019-11-20T16:08:23Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78466', 'http://dx.doi.org/10.26153/tsw/5551']",eng,2003 International Solid Freeform Fabrication Symposium,Open,RP Processes,Integrated Decision Support System for Selection of RP Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/264d702f-86d4-46f1-99d2-2671023f9e7a/download,,"This paper describes an ‘Integrated Decision Support System for the Selection of RP
Processes (IDSSSRP)’. The basic methodology proposed in the IDSSSRP is a Sigma approach
towards benchmarking of the Rapid Prototyping (RP) processes. It characterizes a RP process by
using benchmarking and the sigma approach to assess its capability compared to its potential.
Although the six-sigma approach has basically been a management concept and the success of its
implementation has been on process time reduction and quality improvement, this paper adopts
the use of six-sigma tools and benchmarking in the characterization of RP processes. Apart from
geometrical benchmarks, other benchmarks include mechanical benchmarks and process
benchmarks. Benchmarking individual RP processes facilitates standardization and reduces
variability in the prototypes produced by the processes. Following standardizations of
geometrical, mechanical and process benchmarks, a saturated database can then become very
useful in providing decision support to the end user on a particular process as well as a source of
information for benchmarking new RP machines. A case study of the benchmarking process
developed on the Direct Metal Laser Sintering-Selective Laser Sintering (DMLS-SLS) RP
process is presented using the proposed approach. This paper also outlines the working and
implementation of a web-based decision support system based on the IDSSSRP.",,,,,,
"['Praniewicz, M.', 'Feldhausen, T.', 'Kersten, S.', 'Berez, J.', 'Jost, E.', 'Kurfess, T.', 'Saldana, C.']",2021-11-16T16:37:23Z,2021-11-16T16:37:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90339', 'http://dx.doi.org/10.26153/tsw/17260']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['hardfacing', 'wear resistance', 'stellite-6', 'hybrid manufacturing']",Integrated Hardfacing of Stellite-6 Using Hybrid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8b895029-654f-42fc-b413-36238c014307/download,University of Texas at Austin,"Hybrid manufacturing systems provide a platform for integrated additive, subtractive and
inspection methods on a single machine setup. The present work explores use of hybrid
manufacturing for hardfacing of performance components for improving wear resistance. In this
work, Stellite-6 was applied to a 410 stainless steel substrate using a hybrid manufacturing system
incorporating multi-axis directed energy deposition and machining. Experimental testing was
conducted to determine the effects of hybrid manufacturing parameters on internal porosity,
surface porosity and microstructure in the cladded material, as well as on the roughness of the final
machined surface. Correlation between porosity measurements made by x-ray tomography and
surface inspection is presented and determination of ideal process parameters for hardfacing of
components using hybrid manufacturing systems is briefly discussed. A deposition process is
presented and implemented on a large industrial component. The component is inspected using
dye-penetrant testing and metallographic techniques.",,,,,,
"['Li, Yangsheng', 'Xue, Lijue']",2021-09-30T18:56:36Z,2021-09-30T18:56:36Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88279', 'http://dx.doi.org/10.26153/tsw/15220']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['worn-out components', 'laser cladding', 'non-contact freeform surface measurement', 'software system']",An Integrated Software System for Laser Cladding Repair of Worn-out Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/75b92b9c-d101-4916-bbef-c9a4a6cc4d50/download,University of Texas at Austin,"Recovering worn-out tools/parts could have significant economic benefits. Traditionally,
only some of these worn-out components can be repaired by conventional welding processes.
Laser cladding is a material depositing method by which injected powder material is melted by a
laser beam and re-solidified to form a dense coating with metallurgical bonding onto a substrate.
This technology can be used in the component repair to restore undersized worn-out areas.
Compared to conventional welding processes, laser cladding utilizes much less heat input with
much better control, which drastically reduces or even eliminates distortion, and, therefore,
enables the repair of complex components that cannot be repaired using conventional welding
processes.
Original CAD model does not represent the worn out component anymore and cannot be
used directly for the component repair. Therefore, the first step in the laser cladding repair
procedure is to extract the actual geometry of the components. Non-contact freeform surface
measurement is widely used for this purpose.

We developed a unique software system for laser cladding repair of worn-out components,
which integrates the non-contact freeform surface measurement, the cladding path creation and
the cladding program generation seamlessly. The surface contour is measured along with the
predesigned scanning paths based on its original CAD model. The measured results are filtered
to remove noise, and then compared with the CAD model. Finally, the cladding path planner
creates the cladding program (G-code) based on the selected laser cladding parameters. Through
this integrated software, the undersized worn-out components could be repaired effectively and
easily by laser cladding process.",,,,,,
"['Marsan, Anne L.', 'Allen, Seth', 'Kulkarni, Prashant', 'Dutta, Deba']",2018-12-07T16:21:59Z,2018-12-07T16:21:59Z,1997,Mechanical Engineering,doi:10.15781/T20G3HJ5T,http://hdl.handle.net/2152/71446,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD/CAM', 'LM processes']",An Integrated Software System for Process Planning for Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fcbafc73-5130-4351-8b2a-0f47ed02ad1a/download,,"An integrated process planning system for layered manufacturing (LM) reduces the time
between design and part fabrication and improves the quality of the final part. Process planning
for most LM processes includes part orientation, support structure generation, slicing, and path
planning. In this paper we describe an integrated process planning system we are developing. Our
software accommodates both novel and traditional design models as input, and supports a variety
of LM processes. The modules described in this paper include Solid Builder Module, which generates
a solid model from design data such as medical images, surface functions, or digital elevation
models; Orientation Module, which determines the optimal build orientation of a part and
automatically generates the support structures required; and Adaptive Slicing Module, which
adaptively slices the part.",,,,,,
"['Kruse, A.', 'Reiher, T.', 'Koch, R.']",2021-11-08T22:23:51Z,2021-11-08T22:23:51Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90055', 'http://dx.doi.org/10.26153/tsw/16976']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['Designer', 'design engineering', 'part selection methodology', 'additive manufacturing', 'OptiAMix', 'BMBF']",Integrating AM into Existing Companies - Selection of Existing Parts for Increase of Acceptance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99390cc7-ca9f-4c4a-84a2-4b3aecd0adce/download,University of Texas at Austin,"In many branches in the design engineer department, product designs are just variations of
existing parts. To bring the additive manufacturing technology closer to the Designer, it is
necessary to show them which of their existing, conventionally manufactured parts can be produced
with this technology. A part selection methodology supports designers in the decision whether a
part is suitable for additive manufacturing or not. Due to the potential of the technology, which
was especially seen in the aerospace industries, many criteria of the methodology were initially
adapted for this industry. Furthermore the methodology is based on a quantified weighting system,
which comes to a certain subjectivity. For future use, a development towards a less subjective
methodology should be accomplished. Through a more detailed adaption for individual industries
and a simplification of the input mode, the objectivity of the criteria can be increased. Likewise,
the input time can be reduced by simplifying the questioning. A more efficient part selection will
be achieved by a better weighting system.
In the BMBF project “OptiAMix” this methodology is supposed to be further developed for highly
different branches. By a better weighting system, the part selection will be more efficient.
Therefore, the willingness for the use of the improved selection and for the additive manufacturing
technology will be increased.",,,,,,
"['Altenhofen, C.', 'Loosmann, F.', 'Mueller-Roemer, J.S.', 'Grasser, T.', 'Luu, T.H.', 'Stork, A.']",2021-11-04T20:13:20Z,2021-11-04T20:13:20Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90020', 'http://dx.doi.org/10.26153/16941']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['interactive design', 'mass customization', 'simulation', '3D-printed objects', 'cup holder']",Integrating Interactive Design and Simulation for Mass Customized 3D-Printed Objects - A Cup Holder Example,Conference paper,https://repositories.lib.utexas.edu//bitstreams/179d7749-52e2-4fc7-9c4d-269c14ba7142/download,University of Texas at Austin,"We present an approach for integrating interactive design and simulation for customizing
parameterized 3D models. Instead of manipulating the mesh directly, a simplified interface for
casual users allows for adapting intuitive parameters, such as handle diameter or height of our example object – a cup holder. The transition between modeling and simulation is performed with
a volumetric subdivision representation, allowing direct adaption of the simulation mesh without
re-meshing. Our GPU-based FEM solver calculates deformation and stresses for the current parameter configuration within seconds with a pre-defined load case. If the physical constraints are
met, our system allows the user to 3D print the object. Otherwise, it provides guidance which parameters to change to optimize stability while adding as little material as possible based on a finite
differences optimization approach. The speed of our GPU-solver and the fluent transition between
design and simulation renders the system interactive, requiring no pre-computation.",,,,,,
"Asiabanpour, Bahram",2021-09-23T19:22:42Z,2021-09-23T19:22:42Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/88018', 'http://dx.doi.org/10.26153/tsw/14960']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'process development']",Integrating Rapid Prototyping into Product and Process Development,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f6b5806-bc87-4014-bc77-45e388ffb7c2/download,,"Rapid prototyping concepts and skills are being taught to undergraduate manufacturing
engineering students at Texas State University-San Marcos, not as an independent course, but as a part of
the broad concept of product and process development. In such approach, students get a hands-on
experience in a variety of rapid prototyping processes such as FDM, LOM, Zcorp 3DP, and 3D system’s
InVision and they apply them in their industry-sponsored or research-based senior capstone design
projects. In such approach students get a good understanding about the specifications, cost, and quality of
the parts fabricated by each rapid prototyping machine. They also learn how to select the optimum
process for each component of their product. In this paper, teaching and assessment methods for such
learning experience are explained and a few samples of the previous projects are presented.",,,,,,
"['Swank, M.L.', 'Strucker, B.E.', 'Medina, F.R.', 'Wicker, R.B.']",2021-09-28T18:57:28Z,2021-09-28T18:57:28Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88153', 'http://dx.doi.org/10.26153/tsw/15094']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['automated deposition system', 'support materials', 'Ultrasonic Consolidation', 'UC technology', 'FDM technology']",Integrating UC and FDM to Create a Support Materials Deposition System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b6d05ce-3a40-4409-9df1-456904b886a5/download,University of Texas at Austin,"Currently there is no automated deposition system available for support materials in
Ultrasonic Consolidation. Support materials are important to the UC technology because of the
benefits that can be geometrically achieved. Without an integrated support materials system
many geometries and features will be impossible to create. This paper describes the approach
taken to integrate UC and FDM in order to automatically deposit materials as a support in a UC
machine. This includes the process setup, design, and planning. Finally a build process
integrating the two machines is shown to demonstrate that automated support material deposition
in UC is possible.",,,,,,
"['Hernandez, Ludwing A.', 'Strucker, Brent']",2021-09-28T19:00:16Z,2021-09-28T19:00:16Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88154', 'http://dx.doi.org/10.26153/tsw/15095']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['nScrypt Smart Pump', 'Solidica Formation', 'direct write nozzle', 'ultrasonic consolidation', 'rapid fabrication']",Integration & Process Planning for Combined Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e76ece6-48ee-4131-943a-7665ec9f4a98/download,University of Texas at Austin,"A research project is underway to integrate an nScrypt Smart PumpTM 100 direct
write nozzle with a Solidica FormationTM ultrasonic consolidation machine to rapidly
fabricate parts with novel multi-functional features. The process of integration of both
machines has been addressed, and an appropriate process planning sequence to exploit
the capabilities of the integrated technologies is developed. General processing guidelines
are formulated, and form the basis for further fundamental research and for the
production of proof of concept multi-functional parts to demonstrate the usefulness of
this integration.",,,,,,
"['Frank, Matthew C.', 'Croghan, Jakob', 'Larson, Samantha', 'Beguhn, Logan']",2021-11-16T16:31:59Z,2021-11-16T16:31:59Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90337', 'http://dx.doi.org/10.26153/tsw/17258']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['integration challenges', 'metal AM', 'plastic AM', 'CNC milling machine', 'in-envelope hybrid manufacturing', 'additive manufacturing', 'subtractive manufacturing']",Integration Challenges with Additive/Subtractive In-Envelope Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8c9d3f46-4ca9-4734-aef5-ff9a03fe5f13/download,University of Texas at Austin,"There are significant practical challenges when combining additive and subtractive
manufacturing systems. The integration of AM and machining processes can be done sequentially
or in-envelope. A sequential example would be where an AM part is removed from the build plate
and then fixtured into a milling machine; essentially post-processing a near-net shape part.
Alternately, an AM system can be added to a milling machine or a milling process can be added
to an AM system, which we would refer to as in-envelope. This paper presents some of the
practical challenges of in-envelope hybrid manufacturing; both metal and plastic AM within a
CNC milling machine. In this work, a method to accomplish iterative machining in the presence
of extra material allowance and limited cutting tool lengths will be described. In addition,
preliminary work on accommodating multi-materials within a hybrid system will be presented.",,,,,,
"['Suh, Young S.', 'Wozny, Michael J.']",2018-11-08T14:48:27Z,2018-11-08T14:48:27Z,1995,Mechanical Engineering,doi:10.15781/T24M91W5D,http://hdl.handle.net/2152/69878,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD', 'prototypes']",Integration of a Solid Freeform Fabrication Process into a Feature-Based CAD System Environment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8300e342-b899-4cb6-bf4c-62c5ccfdd75f/download,,"To cope with the increasing market competition, the concurrent engineering (CE) concept is
being adopted by many companies to reduce the cost and the cycle time for manufacturing quality
parts. To build a successful CE system where designers and manufacturing experts work
simultaneously, the appropriate management of the product information flow among the users is
essential. The product information include high-level data such as design intent, part functionality
and manufacturing processes, which traditional CAD systems cannot support. To support such
high-level information beyond geometric data in the CE system, feature-based CAD systems have
been introduced to associate engineering meaning to the shapes of the CAD model components. In
these systems, users can manipulate the CAD models in terms offeatures, and software algorithms
can simulate the human behavior by manipulating the high-level feature entities, as oppose to the
low-level geometric reasoning processes with blind searching algorithms.
One of the primary application of the current SFF processes is to fabricate design prototypes for
fast design verification: The process is identified to be a valuable tool in the CE environment
because it can reduce the significant amount of design cycle time. Therefore"" it is desirable that the
SFF process software is fully integrated into the environment by taking a feature-based approach.
As the process requires extensive geometric reasoning procedures that are time consuming and
require complex algorithms, the feature-based approach is appropriate, and more intelligent
processing is possible. Also, an algorithm can be easily customized",,,,,,
"['Rodriguez, Emmanuel', 'Medina, Francisco', 'Espalin, David', 'Terrazas, Cesar', 'Muse, Dan', 'Henry, Chad', 'MacDonald, Eric', 'Wicker, Ryan B.']",2021-10-06T22:45:26Z,2021-10-06T22:45:26Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88465', 'http://dx.doi.org/10.26153/tsw/15402']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'thermal imaging', 'infrared camera', 'fabrication control']",Integration of a Thermal Imaging Feedback Control System in Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a6ca23d9-0fe5-418e-a693-675d7cd5efeb/download,University of Texas at Austin,"A thermal imaging system using an infrared (IR) camera was incorporated in the
fabrication process of an Arcam A2 Electron Beam Melting system to provide layer-by-layer
feedback and ensure quality and defect free products. Using the IR camera, build chamber
surface temperature profiles were imaged and analyzed, providing information used to modify
build settings for the next build layer. Individual part temperatures were also monitored and
modified to achieve a more uniform bed temperature. The thermal imaging information can also
be used as a quality control tool to detect imperfections during the build. Results from the
integration of the camera in the system as well as use of the thermal images in process
monitoring and control is described.",,,,,,
"['Robinson, Christopher J.', 'Stucker, Brent', 'Lopes, Amit J.', 'Wicker, Ryan', 'Palmer, Jeremy A.']",2020-02-27T19:44:19Z,2020-02-27T19:44:19Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80096', 'http://dx.doi.org/10.26153/tsw/7117']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic Consolidation,Integration of Direct-Write (DW) and Ultrasonic Consolidation (UC) Technologies to Create Advanced Structures with Embedded Electrical Circuitry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9d682a17-2c52-4f43-b0a1-6c4e458546fa/download,,"In many instances conductive traces are needed in small, compact and enclosed areas.
However, with traditional manufacturing techniques, embedded electrical traces or antenna
arrays have not been a possibility. By integrating Direct Write and Ultrasonic Consolidation
technologies, electronic circuitry, antennas and other devices can be manufactured directly into a
solid metal structure and subsequently completely enclosed. This can achieve a significant
reduction in mass and volume of a complex electronic system without compromising
performance.",,,,,,
"['Pintant, T', 'Sindel, M.', 'Greul, M.', 'Burblies, A.', 'Wiklening, C.']",2018-10-03T15:21:21Z,2018-10-03T15:21:21Z,1994,Mechanical Engineering,doi:10.15781/T2DZ03M36,http://hdl.handle.net/2152/68643,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Investment casting', 'Laser sintering', 'Rapid prototyping']",Integration of Numerical Modeling and Laser Sintering with Investment Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a799964f-7b43-406a-bb20-14b5f64b811f/download,,"Industry has a great demand for metallic prototypes to speed up product development. At
present there are several RP-technologies for direct fabrication of metal components in
development. Today secondary processing of polymer or wax models, like investment
casting or sand casting, is a very common way for the production of metallic prototypes.
There are, however, several problems in investment casting resulting from laser sintered
models made of wax or polycarbonate.
Recently a polymer mixture consisting of nylon material and a second polymer has been
tested with the laser sinter process in a newly developed sinter machine (EOSINT 350 -
60). Shells for investment casting could be prepared easily with the models in a
conventional assembly-line. Several castings of laser sintered models in Al were
successfully realized.
In future, integration of modeling based on FEM calculations with RP for castings will
become more important. Calculations will support the designer to optimize the structure of
components and their processing. A viable method will be presented where a new FEM
based calculation method to optimize the structure design of a model is integrated with RP.
Optimizing castings with FEM will be supported by integration with RP.",,,,,,
"['Hague, R.', 'Campbell, I.', 'Dickens, P.', 'Reeves, P.']",2019-10-18T17:13:07Z,2019-10-18T17:13:07Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76267', 'http://dx.doi.org/10.26153/tsw/3356']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Integration of Solid Freeform Fabrication in Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e8508cb-a677-4b59-9891-f134d760c5ee/download,,"During the last few decades, designers have been educated to develop designs with restricted
geometry so that parts can be made easily. The revolutionary aspect of Rapid Manufacturing will be
that geometry will no longer be a limiting factor. The introduction of Rapid Manufacturing will have a
number of effects on Design. It will be possible to have re-entrant shapes without complicating
manufacturing, no draft angles, variable wall thickness, no split lines and fewer parts leading to easier
assembly and lower stock.
The individual designer’s method of working will change with the introduction of Rapid
Manufacturing and also there will be changes to the overall design process. Examples will be the
elimination of prototype and pre-production stages, as end part manufacture will occur as soon as
the CAD is finished. This will affect project management practices and sign-off procedures.",,,,,,
"['Cheng, Lin', 'Zhang, Pu', 'Biyikli, Emre', 'Bai, Jiaxi', 'Pilz, Steve', 'To, Albert C.']",2021-10-21T18:43:57Z,2021-10-21T18:43:57Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89424,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'topology optimization', 'cellular structure', 'reconstruction']",Integration of Topology Optimization with Efficient Design of Additive Manufactured Cellular Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/197ee039-06b0-47fc-9515-58b753d6f387/download,University of Texas at Austin,"Cellular structures are promising candidates for additive manufacturing to design
lightweight and complex parts to reduce material cost and enhance sustainability. In the paper,
we focus on the integration of the topology optimization with the additive manufactured cellular
structures. In order to take advantage of these two technologies for lightweight manufacturing, a
totally new design and CAD method is developed to build up the bridge between the optimal
density distribution and the cellular structure. First, a systematic theoretical and experimental
framework is provided to obtain the mechanical properties of cellular structures with variable
density profile. Second, a revised topology optimization algorithm is introduced to optimize
arbitrary 3D models with given boundary conditions. In this process, the minimum compliance
problem and allowable stress problem are considered to get the relative density distribution.
Third, CAD methods are developed to obtain the function between the local relative density and
the variable density of cellular structure. With the aid of the function, one can convert the density
distribution to the cellular vertex radius distribution and build variable density cellular structures
in the given parts. Finally, a real part named pillow bracket is designed by this process to
illustrate the efficiency and reliability of the new method.",,,,,,
"['Wang, Fangquan', 'Liou, Frank', 'Sparks, Todd']",2021-10-28T14:43:38Z,2021-10-28T14:43:38Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89654,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['computer aided design', 'CAD', 'functional gradient materials', 'source-based', 'voxel-based']",Integration of Voxel Based and Source Based Representation for Computer Aided Design of Functional Gradient Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0251655a-067c-4e37-abc9-8993bab7ebad/download,University of Texas at Austin,"Functionally Gradient Materials (FGMs) feature smooth transition from one material to
another within a single object. FGMs modeling is considered to be one of the new challenges in
Computer Aided Design area. To overcome this challenge, this paper presents the integration of a
source-based and voxel-based approach to model FGMs. The input of STL format can be meshed
and voxelized. The material composition and material varying information in each voxel can be
generated from control sources. In addition, surface source is used to define default material
information, and several filtering methods, including Gaussian filter, Average filter, are applied to
blend FGMs for each voxel.",,,,,,
"['Liou, Frank W.', 'Leu, Ming C.', 'Landers, Robert G.']",2021-10-05T15:39:13Z,2021-10-05T15:39:13Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88393', 'http://dx.doi.org/10.26153/tsw/15332']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'education program', 'society', 'societal integration', 'Missouri University of Science and Technology']",Interactions of an Additive Manufacturing Program with Society,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e6e42722-51f8-46a6-9e25-b287511bd6e8/download,University of Texas at Austin,"Additive Manufacturing (AM) has shown considerable promise for the future but also
proposes some challenges. Many AM barriers tend to be non-technical and instead are humancentric issues such as lack of education of practitioners in AM capabilities, cultural differences,
vested interests, and potentially lack of imagination. It is highly desirable for all research and
educational institutions to help address these issues. This paper summarizes the additive
manufacturing research and education program at the Missouri University of Science and
Technology (Missouri S&T) and its interactions with various constituents, including K-12
students, undergraduate and graduate students, distance students, and industry.",,,,,,
"['Choi, S. H.', 'Samavedam, S.']",2019-03-04T17:29:52Z,2019-03-04T17:29:52Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73528', 'http://dx.doi.org/10.26153/tsw/678']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['evalutaion', 'concept']",An Interactive Virtual System for Simulation and Optimization of Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4a672eb-bf17-4289-82bc-6487abb96154/download,,"The paper describes the development of a computer system for simulation and optimization of
rapid prototyping (RP) processes. The system provides a test-bed for virtual prototyping by
integrating product design and RP with simulation and realistic visualization techniques. It
enhances the dimensional accuracy and reduces the build-time of product prototypes. The
virtually fabricated parts may be exported in VRML format over the Internet for effective
communication between the manufacturer and the customer. The designer may use the system
to design-build-break as many parts as required at a relatively low cost andin a short period
of time. Therefore, virtual simulation of RP processes facilitates tuning of the control
parameters according to the requirements, and hence reduces the number of physical
prototypes needed to produce a part.",,,,,,
"['Jacobsen, A.J.', 'Kolodziejska, J.A.', 'Doty, R.', 'Fink, K.D.', 'Zhou, C.', 'Roper, C.S.', 'Carter, W.B.']",2021-10-01T00:25:55Z,2021-10-01T00:25:55Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88308', 'http://dx.doi.org/10.26153/tsw/15249']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['open-cellular materials', 'micro-scale truss', 'lattice features', 'interconnected self-propagating photopolymer waveguides', 'three-dimensional open-cellular polymer', 'bio-scaffolds']",Interconnected Self-Propagating Photopolymer Waveguides: An Alternative to Stereolithography for Rapid Formation of Lattice-Based Open-Cellular Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f494cc54-5395-4939-be7d-fab110691458/download,,"Recently, a new technique has been developed to create unique open-cellular materials with
micro-scale truss, or lattice features ranging from tens to hundreds of microns. These materials
are formed from a three-dimensional, interconnected array of self-propagating photopolymer
waveguides. By utilizing this self-propagating effect, three-dimensional open-cellular polymer
materials can be formed in seconds. In addition, intrinsic to the process is the ability to control
specific micro-lattice parameters which ultimately affect the bulk material properties. Unlike
stereolithography, this new fabrication technique is rapid (~ minutes to form an entire part) and
relies on a single two-dimensional exposure surface to form three-dimensional structures
(thickness > 25 mm possible). This combination of speed and planar scalability opens the
possibility for large-scale mass manufacturing. The utility of these new materials range from
lightweight energy absorbing structures to thermal management materials to bio-scaffolds.",,,,,,
"['Janaki Ram, G. D.', 'Yang, Y.', 'Nylander, C.', 'Aydelotte, B.', 'Stucker, B. E.', 'Adams, B. L.']",2020-03-09T15:12:35Z,2020-03-09T15:12:35Z,9/5/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80193', 'http://dx.doi.org/10.26153/tsw/7212']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Interface Microstructures and Bond Formation in Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b13365d9-24a0-42c0-93f4-6193081e6765/download,,"The quality of ultrasonically consolidated parts critically depends on the bond quality
between individual metal foils. This necessitates a detailed understanding of interface
microstructures and ultrasonic bonding mechanism. There is a lack of information on interface
microstructures in ultrasonically consolidated parts as well as a lack of consensus on the
mechanism of metal ultrasonic welding, especially on matters such as plastic deformation and
recrystallization. In the current work, interface microstructures of an ultrasonically consolidated
multi-material Al 3003-Ni 201 sample were analyzed in detail using optical microscopy,
scanning electron microscopy, energy dispersive spectroscopy, and orientation imaging
microscopy. Based on the results of microstructural studies, the mechanism of metal ultrasonic
welding has been discussed. The reasons for formation of defects/unbonded regions in
ultrasonically consolidated parts have also been identified and discussed",,,,,,
"['Vail, N.K.', 'Wilke, W.', 'Bieder, H.', 'Jiinemann, G.']",2018-11-15T20:58:46Z,2018-11-15T20:58:46Z,1996,Mechanical Engineering,doi:10.15781/T23N21073,http://hdl.handle.net/2152/70280,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'REEN', 'reverse engineering']",Interfacing Reverse Engineering Data to Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9fc4df49-dc47-4770-974d-f7b817c0cb54/download,,"Rapid prototyping has become an increasing part of product development process chains resulting in
reduced time to market and reduced development costs. As manufacturers strive to further reduce
development cycles to maintain market competitiveness, the use ofreverse engineering technologies have
started to play key roles in the product development cycles. Integration of these technologies into existing
development cycles provides tools to maintain design integrity during development stages as well as
between successive product lines. One aspect ofreverse engineering is the intert'acing of data obtained
from these technologies to manufacturing processes such as rapid prototyping. This paper discusses work
at Daimler-Benz to develop a set ofinterlacing tools as part of a larger reverse engineering process loop.
These tools include facilities to generate contiguous surt'ace meshes from a collection ofmeasured views
as well as automatic feature detection and hole closure.",,,,,,
"['Pedersen-Bjergaard, Jonathan Taulo', 'Christensen, Mathias Michael', 'Brander, Marco', 'Seta, Berin', 'Pedersen, David Bue', 'Spangenberg, Jon']",2023-01-20T16:43:23Z,2023-01-20T16:43:23Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117264', 'http://dx.doi.org/10.26153/tsw/44145']",eng,2022 International Solid Freeform Fabrication Symposium,Open,thermoset,Interlayer Mechanical Properties of Thermoset Components Produced by Material Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b264a967-759d-4b04-8793-0d9edf6338fc/download,,"Material extrusion additive manufacturing (MEX-AM) with thermoset media is of interest 
as its unique material properties are advantageous for many applications. However, thermoset 
MEX-AM’s resultant interlayer mechanical properties have not yet been fully ascertained. In this 
study, a robot arm and extrusion system are used to 3D print a two-component polyurethane with 
depositions of varying holding intervals between layers, to quantify the effect on interlayer-
stiffness and –strength. The material is extruded through a 7 mm nozzle to fabricate 42 mm high 
walls with a width equal to a single strand. The bulk- and interlayer mechanical properties are 
measured through tensile testing of dogbone samples. The results indicate that the interlayer 
mechanical properties do not reduce as compared to the bulk behavior.",,,,,,
"['Wood, Nathaniel', 'Mendoza, Heimdall', 'Boulware, Paul', 'Hoelzle, David J.']",2021-11-18T18:13:03Z,2021-11-18T18:13:03Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90452', 'http://dx.doi.org/10.26153/tsw/17373']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['internal temperature distributions', 'powder bed fusion', 'stainless steel 316']",Interrogation of Mid-Build Internal Temperature Distributions Within Parts Being Manufactured via the Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b19bdf2-c3ee-479e-8cc9-b364052efba4/download,University of Texas at Austin,"This work reports on the measurement of the internal temperature distributions of parts being
manufactured via the Powder Bed Fusion (PBF) process. Eight test coupons were machined from
a piece of wrought 304 stainless steel (SS). Thermocouples were inserted into the test coupon interiors to sample internal thermal history. The coupons were then placed into the open architecture
laser PBF machine housed at EWI and covered to their uppermost surfaces with 316 SS powder.
Three tests were executed: First, the laser rastered over the coupons without inducing melting.
Second, the laser rastered over the coupons while melting the exposed faces. Lastly, five layers of
316 SS were built atop the coupons. The main result is a comprehensive data set of a multitude
of measured physical inputs and outputs under typical build conditions: embedded thermocouple
temperatures, laser centroid, laser power, and infrared imagery of the exposed coupon faces.",,,,,,
"['Marchelli, Grant', 'Storti, Duane', 'Ganter, Mark', 'Prabhakar, Renuka']",2021-09-30T13:07:47Z,2021-09-30T13:07:47Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88227', 'http://dx.doi.org/10.26153/tsw/15168']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['virgin glass', 'recycled glass', '3D printing', '3DP glass systems']",An Introduction to 3D Glass Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c8f59e37-727f-4534-8c81-0dd629a24ce2/download,University of Texas at Austin,"This paper provides an overview of the process behind successfully adapting new materials, namely
virgin glass and recycled glass, to 3D printing. The transition from 3DP ceramic systems to glass systems
will be examined in detail, including, the necessary modifications to binder systems and printing
parameters. We present preliminary engineering data on shrinkage and density as functions of peak firing
temperature. In addition, we will provide a brief introduction to the complexities faced in realizing an
adequate and repeatable firing method for printed glass.",,,,,,
"['Lao, S.', 'Koo, J. H.', 'Morgan, A.', 'Yong, W.', 'Tower, C.', 'Jor, H.', 'Moon, T.', 'Wissler, G.', 'Pilato, L.', 'Luo, Z. P.']",2020-03-09T15:27:45Z,2020-03-09T15:27:45Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80198', 'http://dx.doi.org/10.26153/tsw/7217']",eng,2007 International Solid Freeform Fabrication Symposium,Open,carbon nanofibers,Intumescent Flame Retardant Polyamide 11 Nanocomposites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b06a3771-8b5f-4c64-a722-ced28b48c5b2/download,,"Current polyamide 11 and 12 are lacking in fire retardancy and high strength/high heat
resistance characteristics for a plethora of fabricated parts that are desired and required
for performance driven applications. The introduction of selected nanoparticles such as
surface modified montmorillonite (MMT) clay or carbon nanofibers (CNFs), combined
with a conventional intumescent flame retardant (FR) additive into the polyamide
11/polyamide 12 (PA11/PA12) by melt processing conditions has resulted in the
preparation of a family of intumescent polyamide nanocomposites. These intumescent
polyamide 11 and 12 nanocomposites exhibit enhanced polymer performance
characteristics, i.e., fire retardancy, high strength and high heat resistance and are
expected to expand the market opportunities for polyamide 11 and polyamide 12 polymer
manufacturers.
The objective of this research is to develop improved polyamide 11 and 12 polymers with
enhanced flame retardancy, thermal, and mechanical properties for selective laser
sintering (SLS) rapid manufacturing (RM). In the present study, a nanophase was
introduced into the polyamide 11 and combining it with a conventional intumescent FR
additive via twin screw extrusion. Arkema RILSAN® polyamide 11 molding polymer
pellets were examined with two types of nanoparticles: chemically modified
montmorillonite (MMT) organoclays, and carbon nanofibers (CNFs); and Clairant’s
Exolit® OP 1230 intumescent FR additive were used to create a family of FR
intumescent polyamide 11 nanocomposites.
Transmission electron microscopy (TEM) was used to determine the degree of
nanoparticles dispersion. Injection molded specimens were fabricated for physical,
thermal, and flammability measurements. Thermal stability of these intumescent
polyamide 11 nanocomposites was examined by TGA. Flammability properties were
obtained using the Cone Calorimeter at an external heat flux of 35 kW/m
2
and UL 94
Test Method. Heat deflection temperatures (HDT) were also measured. TEM
micrographs, physical, thermal, and flammability properties are presented. FR
intumescent polyamide 11 nanocomposites properties are compared with polyamide 11
baseline polymer. Based on flammability and mechanical material performance, selective
polymers including polyamide 11 nanocomposites and control polyamide 11 will be
cryogenically ground into fine powders for SLS RM processing. SLS specimens will be
fabricated for thermal, flammability, and mechanical properties characterization.",,,,,,
"['Brown, Don R.', 'Subramanyan, Venkatesh', 'Drake, Samuel']",2018-04-12T18:03:44Z,2018-04-12T18:03:44Z,1991,Mechanical Engineering,doi:10.15781/T2TX35P9B,http://hdl.handle.net/2152/64276,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Mechanical Engineering and Computer Science Departments', 'stereolithography', 'inverse geometry']",Inverse Geometry for Stereolithographic Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c61efa9-450c-4a9d-8d30-584d539287f9/download,,"As parts produced by stereolithography form and cure, they warp and shrink
to produce Pitrts that are not quite the san~ ~ as those originally specified. This
research attempts to solve the inverse geomptry problem, that is, what shape
should be specified initially so that the she pe produced is the desired one.
Assuming that 'the process is repeatable, we ~neasure the difference between the
ideal and actua). part dimensions. A finite-element based model is built which
mirrors the distortion from the ideal geometry. A ""pre-deformed"" geometry is
then built so that it deforms to the ideal geometry under the conditions imposed
on the finite element model. This pre-warped geometry is the geometry we seek.",,,,,,
"['Khan, Md Faysal', 'Nezhadfar, P.D.', 'Gradl, Paul R.', 'Godfrey, Donald', 'Diemann, Jacky', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-20T17:02:07Z,2023-01-20T17:02:07Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117267', 'http://dx.doi.org/10.26153/tsw/44148']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser powder bed fusion (L-PBF)', 'AlF357', 'Height dependency', 'Microstructure', 'Porosity', 'Tensile properties']",Investigate the height dependency of the micro-/defect-structure and mechanical properties of additively manufactured AlF357 aluminum alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0068f1c8-8acc-4193-838f-edfe928b205b/download,,"When the laser powder bed fusion (L-PBF) additive manufacturing method is employed to 
build parts with increased heights, there is a possibility that defects are increased in part. This study 
investigates the effect of build height on the micro-/defect-structure and, consequently, the 
mechanical properties of L-PBF AlF357, an Al-Si-Mg alloy family. Tall vertical cylinders of 316 
mm with 15 mm diameter were fabricated and cut into specimens at different heights. Although 
not much difference is observed in the microstructure (grain size and morphology), the defects' 
size and population slightly vary with height. Nonetheless, the tensile properties of the L-PBF 
AlF357 are found to be independent of height. This is ascribed to the approximately identical 
microstructure and marginal difference in the defect's size and distribution along the heights.",,,,,,
"['Taylor, Samantha', 'Jared, Bradley', 'Koepke, Josh', 'Forrest, Eric', 'Beaman, Joseph']",2021-11-18T18:56:20Z,2021-11-18T18:56:20Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90467', 'http://dx.doi.org/10.26153/tsw/17388']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['surface roughness', 'arithmetic roughness', 'roughness parameters', 'applicability', 'metallic additive manufacturing']",Investigating Applicability of Surface Roughness Parameters in Describing the Metallic AM Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78aca229-a5fa-4981-af43-106163d40fb2/download,University of Texas at Austin,"Additive manufacturing (AM) is known for its large variance in mechanical properties.
This is not only true for properties like strength, but also surface roughness. Build settings, which
affect surface roughness, are often chosen to optimize strength or ductility. As part requirements
change, build settings change, thereby changing resultant surface roughness. When describing
surfaces, arithmetic roughness (Ra) is the most common parameter. However, it may not provide
an adequate representation of surface topography for AM parts. Traditional surface roughness
parameters for defining surface topography were well-established before the advent of AM, and
a need has arisen to investigate applicability of these parameters to the unusual surfaces created
through various AM technologies. This study demonstrates that Ra is not a suitable parameter in
correlating surface topography to AM build parameters. Other existing parameters and
combination of parameters will be investigated for their suitability in describing the AM process.",,,,,,
"['Thompson, Matthew J.', 'Whalley, David C.', 'Hopkinson, Neil']",2020-03-10T17:22:57Z,2020-03-10T17:22:57Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80233', 'http://dx.doi.org/10.26153/tsw/7252']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Investigating Dielectric Properties of Sintered Polymers for Rapid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e2737d3-c16f-45f7-8a95-115553809857/download,,"Selective Laser Sintering (SLS) of polymers is the leading technology in the growing field of
Rapid Manufacturing. High Speed Sintering (HSS) is a process that offers the potential to reduce
costs and processing times and thus open significant new markets for Rapid Manufactured parts.
Much academic research has been performed with respect to mechanical properties of Rapid
Manufactured parts, however the area of electrical properties has received little attention to date.
Electrical properties are obviously important in applications that will involve embedding of
circuits with Rapid Manufactured 3D objects. However electrical properties are also important
for a wide variety of electrical products where Rapid Manufactured parts can be used as housings
etc.
This paper focuses on the dielectric properties of parts made by SLS and HSS and compares
properties with those for conventionally processed polymers. Dielectric strength results show
that SLS parts are comparable with injection moulded parts, while HSS parts are inferior to SLS
parts. Dielectric constant and dissipation factor results show that HSS parts are comparable with
injection moulded parts, whilst SLS parts have superior properties. The presence of porosity
(SLS and HSS) and the presence of carbon (HSS) are suggested as reasons behind the variation in
dielectric properties when compared with injection moulded parts.",,,,,,
"['Tanney, Daniel', 'Meisel, Nicholas A.', 'Moore, Jacob']",2021-11-02T18:20:30Z,2021-11-02T18:20:30Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89857,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['recycled PLA', 'PLA', 'material degradation', 'lifecycle', 'material extrusion', 'additive manufacturing']",Investigating Material Degradation Through the Recycling of PLA in Additively Manufactured Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/06a6f180-cdc7-44be-a108-f855e1cda20a/download,University of Texas at Austin,"The field of additive manufacturing (AM) has been expanding rapidly with the decreasing cost
of desktop-scale material extrusion AM systems. As the cost of AM systems decreases, more users
are investing in the technology, including universities, which have turned to AM as an option for
providing wide-scale access to prototyping technology. However, this type of wide-access printing
generates significant waste due to cast-off support material as well as failed prints from
inexperienced users. This paper investigates the feasibility of recycling this cast-off material
through the relationship between the mechanical properties of recycled PLA and the number of
lifecycles it has experienced on a desktop material extrusion machine. A three-stage pelletizing,
extrusion, and printing process is used to investigate recycling of PLA material from cast-off build
material. Additionally, the research investigates how adding virgin pellets to pellets of the recycled
material in various ratios can affect tensile properties.",,,,,,
"['Haigh, B.', 'Lancaster, R.J.', 'Johnston, R.', 'White, M.', 'Minshull, J.']",2021-11-18T00:36:21Z,2021-11-18T00:36:21Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90373', 'http://dx.doi.org/10.26153/tsw/17294']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['Inconel 718', 'laser powder bed fusion', 'small punch', 'microstructure', 'porosity']","Investigating the Build Consistency of a Laser Powder Bed Fused Nickel-Based Superalloy, Using the Small Punch Technique",Conference paper,https://repositories.lib.utexas.edu//bitstreams/d822dee5-54d2-4d90-b6be-bebbd152c7b9/download,University of Texas at Austin,"Inconel 718 (IN718) is a nickel-based superalloy that possesses impressive corrosion
resistance and high strength properties at elevated temperatures, making it an ideal choice for
aerospace applications. However, with the continuous evolution of the jet engine, there is a
strong desire to fabricate more intricate components with less stress-raising features to enable
higher engine efficiencies to be achieved. To overcome this issue, aerospace engineers are
looking at Additive Manufacturing (AM) as a potential solution. A limitation of AM is the
transient nature of the microstructure, and it is difficult to produce representative laboratory
scale mechanical test specimens that closely replicate the microstructure of the finished
component. Therefore, it can be beneficial to utilise small-scale test methods, such as the Small
Punch (SP) test, which can obtain mechanical property information from miniaturised
specimens extracted directly from the finished part. In this paper, the small punch test technique
has been adopted to characterise and evaluate the mechanical response of laser powder bed
fused (LPBF) Inconel 718. Results showed a high consistency across builds and certain
orientations exhibited superior properties.",,,,,,
"['Nandi, Indrajit', 'Shamsaei, Nima', 'Shao, Shuai']",2023-01-25T14:23:45Z,2023-01-25T14:23:45Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117289', 'http://dx.doi.org/10.26153/tsw/44170']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'crystal plasticity simulation', 'IN718', 'Defects']",Investigating the effect of defects on the crack initiation of additively manufactured IN718 using crystal plasticity simulations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e82572f3-3023-4384-b303-933e0d76108d/download,,"This study aims to analyze the effect of defects location on the fatigue behavior of additively 
manufactured IN718. A competing mechanism exists between persistent slip bands (PSBs) and 
volumetric defects on the initiation of fatigue cracks in AM IN718 under cyclic loading. Crystal 
plasticity simulations were performed to reveal the relative importance in crack initiation due to defects 
and PSBs. Cyclic loading was applied on a defect laden polycrystalline aggregate and the defect 
locations were systematically varied. The crack nucleation cycles and locations were captured using a 
strain contrast-based crack initiation criterion. The findings suggest that the presence of large defects 
affects the cyclic strain localization and crack initiation behavior of the AM IN718 material.",,,,,,
"['Awenlimobor, A.', 'Smith, D.E.', 'Wang, Z.']",2024-03-26T17:06:36Z,2024-03-26T17:06:36Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124377', 'https://doi.org/10.26153/tsw/50985']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['generalized Newtonian fluid', 'large area additive manufacturing', 'deposition beads']",Investigating the Effect of Generalized Newtonian Fluid on the Micro-Void Development within Large Scale Polymer Composite Deposition Beads,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e05a5797-34a7-47c4-8b88-052705916053/download,University of Texas at Austin,"The formation and development of micro-voids within the bead microstructure of a
polymer composite during the extrusion/deposition additive manufacturing process continues to
be of interest given the adverse effect these features have on part quality. A computational method
is employed here to investigate potential volatile-induced micro-void nucleation mechanism which
simulates the evolution of a single rigid ellipsoidal fiber in purely viscous polymer
extrusion/deposition flow through a Large Area Additive Manufacturing (LAAM) nozzle. Our
previous studies on potential micro-void nucleation mechanisms have assumed a Newtonian fluid
property definition for the polymer melt flow, the current study assesses the effect of assuming a
generalized Newtonian fluid (GNF) model on the fiber’s response. Preliminary findings based on
Jeffery’s flow assumption reveal the fiber’s orientation kinetics are unaffected by the shearthinning fluid behavior, however there is a reduction in the pressure distribution on the fiber’s
surface as the power law index is decreased which is expected to reduce the likelihood for microvoid nucleation.",,,,,,
"['Farhang, B.', 'Ravichander, B.B.', 'Ganesh-Ram, A.', 'Ramachandra, S.', 'Hanumantha, M.', 'Hall, W.', 'Dinh, A.', 'Amerinatanzi, A.', 'Shayesteh Moghaddam, N.']",2021-12-06T22:38:15Z,2021-12-06T22:38:15Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90701', 'http://dx.doi.org/10.26153/tsw/17620']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Inconel 718', 'microstructure', 'Vickers hardness', 'homogenity']",Investigating the Effect of Heat Transfer on the Homogenity in Microstructure and Properties of Inconel 718 Alloy Fabricated by Laser Powder Bed Fusion Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb6ee87f-5cdf-42db-90f4-cb3bd90dfe88/download,University of Texas at Austin,"Laser Powder Bed Fusion (LPBF) of metallic components is associated with microstructure and
inhomogeneity of properties in the fabricated components. In a recent work by the authors, a novel
technique of considering a border surrounding the main part during the LPBF fabrication is
proposed to address the issue of inconsistency in microstructure across the cross section of LPBF-fabricated parts. This study, on the other hand, aims to investigate the effect of such border on the
microstructure homogeneity along the build direction of LPBF-fabricated parts. For this purpose, a
cubic sample surrounded by a cubic border was fabricated to control the rate of heat transfer and
then improve the microstructure across the cross section. Also, a sample with identical dimensions
and the same process parameters was printed without border as a reference to be compared. To
investigate the variation of the properties along the build direction, microstructure and hardness
results were compared between areas near and away the substrate for both samples. For the area
away from the substrate, in both samples, a deeper pool, less surface porosity, and higher Vickers
hardness was observed compared to the area near the substrate. It was found out that, regardless of
the focused area, the sample fabricated with border possesses deeper pools, higher level of density
as well as higher hardness value. However, in term of homogeneity along the build direction, no
significant improvement was observed for the sample fabricated with the cubic border.",,,,,,
"['Bracken, Jennifer', 'Bentley, Zachary', 'Meyer, James', 'Miller, Erik', 'Jablokow, Kathryn W.', 'Simpson, Timothy W.', 'Meisel, Nicholas A.']",2021-11-16T15:52:30Z,2021-11-16T15:52:30Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90321', 'http://dx.doi.org/10.26153/tsw/17242']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['AM workshop', 'idea generation', 'problem solving', 'additive manufacturing']",Investigating the Gap Between Research and Practice in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b920d3d-8657-4e2c-9098-f4f2bc1102af/download,University of Texas at Austin,"Additive manufacturing (AM) provides opportunities to design objects differently than
traditional manufacturing methods allow, but only if designers understand the possibilities AM
presents. In this study, we examined whether an AM workshop combined with an idea generation
session could inspire engineering professionals to use AM solutions to solve current technical
problems they face. All subjects were employees at an organization that will be referred to as
Company X, a multinational commercial organization based in North America. During the study,
we collected ideas for 24 projects generated before and after a training workshop focused on design
for AM. In the workshop, we provided three hours of instruction about design for two metal-based
AM processes. The participants’ ideas were assessed using four specific metrics: (1) cost, (2) time,
(3) completeness of solution, and (4) quality, which was a function of feasibility, usefulness, and
novelty. Using these data, we explored whether the workshop was effective in inspiring the
participants to use AM methods and techniques from AM research in their concept generation and
whether participants’ AM solutions showed improvement in cost, implementation time, and
quality over non-AM designs generated before the workshop.",,,,,,
"['Kaweesa, Dorcas V.', 'Spillane, Daniel R.', 'Meisel, Nicholas A.']",2021-11-02T18:54:10Z,2021-11-02T18:54:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89865,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['functionally graded material', 'fatigue life', 'multi-material specimens', 'material jetted specimens', '3D printing']",Investigating the Impact of Functionally Graded Materials on Fatigue Life of Material Jetted Specimens,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b22495c8-0fce-4e06-80a5-2c6f841852d0/download,University of Texas at Austin,"The capability of Additive Manufacturing (AM) to manufacture multi-materials allows the
fabrication of complex and multifunctional parts with varying mechanical properties. Multi-material AM involves the fabrication of 3D printed objects with multiple heterogeneous material
compositions. The material jetting AM process specifically has the capability to manufacture
multi-material structures with both rigid and flexible material properties. Existing research has
investigated the fatigue properties of 3D printed multi-material specimens and shows that there is
a weakness at the multi-material interface. This paper seeks to investigate the effects of gradual
material transitions on the fatigue life of 3D printed multi-material specimens, given a constant
volume of flexible material. In order to examine the fatigue life at the multi-material interface,
discrete digital-material gradient steps are compared against the true functional gradients created
through voxel-level design. Results demonstrate the negative effects of material gradient
transitions on fatigue life as well as the qualitative material properties of true versus discrete
gradients.",,,,,,
"['Salajeghe, Roozbeh', 'Kruse, Carl Sander', 'Meile, Daniel Helmuth', 'Marla, Deepak', 'Spangenberg, Jon']",2023-01-26T15:55:38Z,2023-01-26T15:55:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117322', 'http://dx.doi.org/10.26153/tsw/44203']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Volumetric additive manufacturing', 'Volume of Fluid', 'Sedimentation', 'Boussinesq approximation', 'ultra-violet (UV) Curing', 'Photopolymerization']",Investigating the influence of thermal and mechanical properties of resin on the sedimentation rate of the printed geometry in the volumetric additive manufacturing technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9144a07f-41a4-4951-af3d-2ec2d9ca7ec6/download,,"y layer, volumetric additive manufacturing produces the whole geometry at the same time. While 
it is faster, creates features with high surface quality, requires no overhang support structures, and can 
print in high-viscosity resins, all of which push the limits of additive manufacturing, this technique is still 
premature and suffers from some effects such as body sedimentation that impacts the geometric fidelity 
and resolution of the final product. The sedimentation rate of the printed body during its formation is 
highly dependent on the resin type, its viscosity, and its curing behavior. Herein, we propose a CFD 
model that takes into account the synergistic effect of reaction-based heating, curing behavior, and 
resin properties to predict the sedimentation rate of the printed geometry. The results show that heating 
effects can slow down the sedimentation rate of the curing part significantly.",,,,,,
"['Galimberti, G.', 'Doubrovski, E.L.', 'Guagliano, M.', 'Previtali, B.', 'Verlinden, J.C.']",2021-11-01T22:26:17Z,2021-11-01T22:26:17Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89782,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['process parameters', 'aesthetic properties', 'selective laser melting', '3D printing']",Investigating the Links Between the Process Parameters and Their Influence on the Aesthetic Evaluation of Selective Laser Melted Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0ed62e24-750d-4d5b-aa6d-8cb498437f23/download,University of Texas at Austin,"This study is a precursor to gaining a deeper understanding of how each parameter of
the Additive Manufacturing (AM) process influences the aesthetic properties of 3D printed
products. Little research has been conducted on this specific aspect of AM. Using insights
from the work presented in this paper, we intend to develop design support tools to give the
designer more control over the printed products in terms of aesthetics.
In this initial work, we fabricated samples using Selective Laser Melting (SLM)
technology, and investigated the parameters geometry, building strategy, and post-processing.
We asked participants to evaluate the visual and physical interaction with the manufactured
samples. Results show that, in addition to geometry and post-processing, the aesthetic
evaluation can also be strongly influenced by the SLM process’ building strategy. This
understanding will enable us to develop tools to give designers more control over the part’s
aesthetic appearance. In addition, we present a systematic procedure and setup to evaluate the
aesthetic appearance of products manufactured using AM.",,,,,,
"['Woods, E.', 'Fromhold, M.', 'Wildman, R.', 'Tuck, C.']",2021-11-30T22:09:10Z,2021-11-30T22:09:10Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90566', 'http://dx.doi.org/10.26153/tsw/17485']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['gradient index optics', 'modulation', 'two-photon polymerization']",Investigating the Production of Gradient Index Optics by Modulating Two-Photon Polymerisation Fabrication Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/92e0bd59-fa8b-43a4-ac37-d40d8eb1c47b/download,University of Texas at Austin,"Two-photon polymerisation (TPP) is an additive manufacturing technique allowing the
fabrication of arbitrary 3D geometries with sub-micron features. As such, TPP is a promising
technique for fabricating optical metamaterials. The electromagnetic (EM) properties of
metamaterials arise from their geometrical structure rather than their material constituents alone.
By introducing variations across the unit cells of a metamaterial spatially varying EM properties
can be created. In this way, gradient index (GRIN) optics can be produced which are useful for
reducing coupling losses and creating compact optical systems. This work looks at modulating
fabrication parameters to achieve geometrical variations. Line widths of IP-L 780 are measured
on an array of lines fabricated at different laser powers and scan speeds. Proof of concept
woodpile structures are also fabricated where laser power is changed for individual lines in the
structure resulting in geometrical changes. Changing fabrication parameters along a single scan
line is also investigated.",,,,,,
"['Sampson, Bradley J.', 'Morgan-Barnes, Courtney', 'Stokes, Ryan', 'Doude, Haley', 'Priddy, Matthew W.']",2023-01-27T13:34:20Z,2023-01-27T13:34:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117328', 'http://dx.doi.org/10.26153/tsw/44209']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser powder bed fusion', 'selective laser melting', 'in-situ process monitoring', 'Ti6Al4V', 'thermal monitoring', 'additive manufacturing']",Investigating the Relationship Between In-Process Quality Metrics and Mechanical Response in the L-PBF Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d58c3266-ee30-4513-a89f-9a639882fd2c/download,,"Laser powder bed fusion (L-PBF) additive manufacturing is a process that utilizes a high-
powered laser to build near net-shaped parts in a layer-by-layer fashion using metal powder as the 
feedstock material. Traditionally, the analysis of L-PBF produced parts has relied solely on post-
build characterization to understand the relationship between the printing process and the final 
mechanical properties. Recent developments of in-process quality assurance systems, such as 
Sigma Additive Solutions’ PrintRite3D, can measure in-process thermal signatures and melt pool 
disturbances in real-time. This research aims to examine the relationship between process 
parameters (e.g., scan strategy, scanning speed, and layer thickness) and in-process quality metrics 
(IPQMs) captured by the PrintRite3D system on a Renishaw AM400. The mechanical response of 
multiple part geometries (NIST residual stress bridges, single-arched bridges) and build materials 
(Ti6Al4V) includes residual stress deflection and hardness; the results are compared with the 
IPQMs.",,,,,,
"['Snarr, Patrick L.', 'Beaman, Joseph', 'Haas, Derek']",2021-12-06T21:20:58Z,2021-12-06T21:20:58Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90675', 'http://dx.doi.org/10.26153/tsw/17594']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['indirect selective laser sintering', 'thermally induced phase separation']",Investigating Thermally Induced Phase Separation as a Composite Powder Synthesis Technique for Indirect Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e21868d3-a79b-4b22-9915-dc4a7e45eb58/download,University of Texas at Austin,"The nuclear energy and nuclear defense industries have long relied on traditional
manufacturing techniques for fabrication of reactor and weapon components. With the recent
growth of additive manufacturing (AM), the nuclear industry is now asking the question of how
AM could be used to manufacture components found in the nuclear fuel cycle. Many important
components in the nuclear fuel cycle are made from ceramics, including the popular fuel,
uranium oxide. This research investigates an indirect selective laser sintering technique (iSLS)
that can be used to fabricate complex ceramic components. Thermally induced phase separation
(TIPS) was explored as a technique to coat ceramic particles with a polymer, which can then be
employed in an indirect SLS method. Two process variables of TIPS were studied, and the
resulting powder characterized.",,,,,,
"['Tang, Shangyong', 'Wang, Guilan', 'Huang, Cheng', 'Zhang, Haiou']",2021-11-18T01:12:06Z,2021-11-18T01:12:06Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90386', 'http://dx.doi.org/10.26153/tsw/17307']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['WAAM', 'additive manufacturing', 'arc striking', 'arc extinguishing', 'abnormal area', 'bead geometry']",Investigation and Control of Weld Bead at Both Ends in WAAM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3594fd39-2478-40fd-8942-103d224228a0/download,University of Texas at Austin,"Control of bead geometry in wire and arc additive manufacturing is significant as it effect
the whole manufacturing process. However, the weld beads at arc striking and arc extinguishing
area are generally abnormal in which the dynamical process of the weld bead is unstable. In
this paper, the abnormal areas in arc striking and arc extinguishing point were investigated.
Different parameters were used to make the width and height closed to the middle area in the
AS and AE point. A burning-back method was proposed to fill up the slant plane in AE point.
Experiments were conducted to study and verify the abnormal areas of the weld bead. And the
experimental result indicated that the methods at both ends were available and preferable in the
optimization of weld beads.",,,,,,
"['Montgomery, J.', 'Vaughan, M.', 'Crawford, R.']",2021-09-29T17:25:46Z,2021-09-29T17:25:46Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88194', 'http://dx.doi.org/10.26153/tsw/15135']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['lower-leg prosthetic socket', 'adaptive sockets', 'selective laser sintering', 'additive manufacturing']",Investigation and Design of an Actively Actuated Lower-Leg Prosthetic Socket,Conference paper,https://repositories.lib.utexas.edu//bitstreams/089d6372-ed8d-41e0-a520-cb6c8c742d25/download,University of Texas at Austin,"A prosthetic socket worn by an amputee must serve a wide variety of functions, from
stationary support to the transfer of forces necessary to move. Fit and comfort are important
factors in determining the therapeutic effectiveness of a socket. A socket that does not fit the
subject well will cause movement problems and potentially long-term health issues. Because a
subject's residual limb changes volume throughout the day, it is desirable that the socket adapt to
accommodate volume changes to maintain fit and comfort. This paper presents research to
manufacture adaptive sockets using selective laser sintering (SLS). This additive manufacturing
process allows freedom to design a socket that has both compliant areas that can adapt to
changes to the residual limb, as well as rigid regions to provide necessary support for the limb. A
variety of concepts are discussed that are intended for manufacture by SLS, and that feature
flexible inner membranes in various configurations. For each concept the membrane will be
inflated or deflated to match the limb’s change in volume. and the paper also presents a study to
determine SLS machine parameters for optimal build results, as well as results from initial
pressure-deflection experiments.",,,,,,
"['Hecker, F.', 'Hirsch, A.', 'Moritzer, E.']",2021-12-07T17:14:26Z,2021-12-07T17:14:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90724', 'http://dx.doi.org/10.26153/tsw/17643']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['arburg plastic freeforming', 'APF', 'residence time', 'material degradation']",Investigation and Modeling of the Residence Time Dependent Material Degradation in the Arburg Plastic Freeforming,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d783335-c5f5-4d04-aef9-da5a808fbf06/download,University of Texas at Austin,"The Arburg Plastic Freeforming (APF) is an additive manufacturing process with which
three-dimensional, thermoplastic components can be produced layer by layer. One
disadvantage of the APF is the long residence time of the molten material in the plasticizing
unit compared to conventional injection moulding. The dosing volume is emptied very slowly
due to only discharging fine plastic droplets. As a result, long residence times can be expected,
which can lead to thermal degradation of the material.
The aim of this study was to develop a model for calculating the residence time of the
material in the APF. The residence time of the material in the thermally critical dosing volume
is predicted using software developed in-house. The accuracy of the model could be verified
by experimental investigations. Finally, the thermal degradation of the material was
investigated by analyzing the correlation to the mechanical properties of tensile strength
specimens.",,,,,,
"['Kigure, T.', 'Yamauchi, Y.', 'Niino, T.']",2023-03-30T16:34:57Z,2023-03-30T16:34:57Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117705', 'http://dx.doi.org/10.26153/tsw/44584']",eng,2022 International Solid Freeform Fabrication Symposium,Open,laser sintering,Investigation into effect of beam defocusing in low temperature laser sintering of  PEEK,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba763f40-3249-4e23-bc77-c8d7f82dff67/download,,"Laser sintering of PEEK with the same powder bed temperature as PA12, which 
is lower than recrystallization temperature of PEEK, has been achieved at pervious study. 
However, the process at low bed temperatures requires a greater energy supply to melt 
the material, and it increases the risk of thermal decomposition. Expansion of spot size 
by defocusing is one of the effective ways to reduce the peak intensity of beam and allow 
providing more energy to the same laser irradiation range as avoiding the decomposition. 
In this study, specimens were prepared with the same amount of energy and difference 
beam diameters, to observe difference in internal voids and thermal decomposition of 
specimens. As a result, it was indicated that large spot size is effective on high energy 
supply without thermal decomposition and suppressing internal voids.",,,,,,
"['Kigure, Takashi', 'Yamauchi, Yuki', 'Niino, Toshiki']",2021-12-01T23:29:59Z,2021-12-01T23:29:59Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90656', 'http://dx.doi.org/10.26153/tsw/17575']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'PEEK', 'powder bed temperature']",Investigation into Laser Sintering of PEEK using Commercially Available Low Powder Bed Temperature Machine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d03c00ec-c67f-4229-aa4b-99421507a10c/download,University of Texas at Austin,"Polyetheretherketone (PEEK) is one of the highest performance plastics in terms
of heat and chemical resistance and mechanical strength. Laser sintering of PEEK
requires high powder bed temperature above 300℃, and this pushes up machine price
and pulls down powder recycle rate which leads to high material cost.
The authors are proposing a modified laser sintering process which allows the bed
temperature to be set lower than recrystallization temperature, namely low temperature
process. In this research, bed temperature of 170 ℃, which is typical for PA12 process,
and bed temperature of 200 ℃ which is same as previous study were tested. As a result,
parts with a high relative density of more than 95% were obtained at both powder bed
temperatures, and parts with a tensile strength of 80 MPa were obtained at a powder bed
temperature of 170 °C. This shows that laser sintering of PEEK can be processed with a
commercially available laser sintering machine resulting in drastic cost cut in terms of
machine and material costs.",,,,,,
"['Shrestha, Subin', 'Cheng, Bo', 'Chou, Kevin']",2021-10-26T18:21:34Z,2021-10-26T18:21:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89550,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['effective thermal conductivity', 'electron beam additive manufacturing', 'marangoni effect', 'thermo-fluid model']",An Investigation into Melt Pool Effective Thermal Conductivity for Thermal Modeling of Powder-Bed Electron Beam Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3c64ef28-ed0b-4403-ad5d-f18c3e7ab412/download,University of Texas at Austin,"In this study, the effective thermal conductivity of a melt pool in the powder-bed electron
beam additive manufacturing (EBAM) process was investigated using a numerical technique.
Although a thermo-fluid model is preferred to predict the melt pool flow, computational cost is
high. The alternative is to use an effective thermal conductivity that may capture the convection
effect from the melt pool flow. Using finite volume method, first a thermo-fluid model was
developed to simulate process temperatures in EBAM using Ti-6Al-4V powder and validated
against experiment. Separately, a thermal simulation using an effective thermal conductivity for
the liquid phase was conducted. The value of the effective thermal conductivity in the thermal
simulation was adjusted so that the thermal responses approach those from the validated thermo-fluid simulations. The results show that the accuracy of thermal model depends on the process
parameter. Maximum error of 35% was observed for beam diameter 0.55 mm.",,,,,,
"['Zhang, Shanshan', 'Lane, Brandon', 'Whiting, Justin', 'Chou, Kevin']",2021-11-11T16:53:29Z,2021-11-11T16:53:29Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90248', 'http://dx.doi.org/10.26153/tsw/17169']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser powder-bed fusion', 'laser flash', 'inverse method', 'thermal properties']",An Investigation into Metallic Powder Thermal Conductivity in Laser Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3acdc126-01d7-4a74-852a-263ef586a701/download,University of Texas at Austin,"This study investigates the thermal conductivity of metallic powder in laser powder-bed
fusion (LPBF) additive manufacturing. The intent is to utilize a methodology combining laser flash
testing, finite element (FE) heat transfer modeling, and an inverse method to indirectly measure
the thermal conductivity of nickel-based super alloy 625 (IN625) and titanium alloy (Ti64) powder
used in LPBF processes. A hollow test specimen geometry was designed and built with LPBF
enclosing the un-melted powder to mimic the powder bed conditions. The specimens were then
flash heated in a laser flash system to measure their transient temperature response. Next, a
developed FE model and a multi-point optimization algorithm were applied to inversely analyze
the thermal transient, and extract the thermal diffusivity and conductivity of the powder enclosed
in the specimens. The results indicate that the thermal conductivity of IN625 powder used in LPBF
ranges from 0.65 W/(m·K) to 1.02 W/(m·K) at 100 °C and 500 °C, respectively. On the other hand,
Ti64 powder has a lower thermal conductivity than IN625 powder, about 35 % to 40 % smaller.
However, the thermal conductivity ratio of the powder to the respective solid counterpart is not
much different between the two materials, about 4 % to 7 %, which is largely temperature
independent.",,,,,,
"['Chen, Peng', 'Wen, Shifeng', 'Yan, Chunze', 'Liu, Jie', 'Shi, Yusheng']",2021-11-11T16:08:35Z,2021-11-11T16:08:35Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90230', 'http://dx.doi.org/10.26153/tsw/17151']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'AM', 'selective laser sintering', 'SLS', 'polyamide 6', 'PA6', 'crystalline structure']",Investigation into the Crystalline Structure and sub-Tpm Exotherm of Selective Laser Sintered Polyamide 6,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03af3fe5-e3eb-46ae-9b69-0a49e0fbffad/download,University of Texas at Austin,"Selective Laser Sintering (SLS) has achieved a wide acceptance for direct manufacture
of complex functional components. However, the performance of SLS part still needs
to be improved, in which the crystalline structure plays an important role. Every
crystalline form has specific properties, and the whole material behaviors have great
relationships with the various species and crystalline structure. Therefore, this paper
investigates crystalline structure of laser sintered Polyamide 6 (PA6) and quantifies the
different HT-α and LT-α phases using thermal analysis. The results show that the
sintered parts are uniformly characterized by a relatively stronger (2 0 0) and a weaker
(0 0 2) diffraction peak. This crystalline structure variation is basically consistent for
all SLS parts and independent of laser power. In addition, the sub-Tpm crystallization
transition concerning α phase was found for SLS PA6 part, which is derived from the
release of strain energy absorbed during SLS processing.",,,,,,
"['Egodawatta, A. K.', 'Harrison, D. K.', 'De Silva, A. K. M.', 'Haritos, G.']",2020-02-14T14:54:18Z,2020-02-14T14:54:18Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79982', 'http://dx.doi.org/10.26153/tsw/7007']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,An Investigation into the Effect of the Shell on SALM Processed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/936941ab-2ac1-469a-a7ba-82b33693c06e/download,,"Shell Assisted Layer Manufacturing (SALM) is a novel process for rapid prototyping/
tooling/ manufacture (RP/RT/RM) which is presently undergoing feasibility studies. SALM is
based on layered manufacturing technology (LMT). Initially it develops the shell (boundaries)
of a selected layer using a technique similar to fused deposition modelling (FDM). The
developed shell is filled with a UV curable resin and is exposed to UV radiation for curing.
This procedure is repeated until the complete part is built. This paper compares and contrasts
properties of parts made using two options available with the SALM technique: building the
part using a soluble shell (FDM support structure material, finally dissolved to recover the
part); or using a polymer material such as ABS that is bonded with the resin whilst making
the part.",,,,,,
"['Saleh, Naguib', 'Mansour, Saeed', 'Hague, Richard']",2019-10-23T15:20:28Z,2019-10-23T15:20:28Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76759', 'http://dx.doi.org/10.26153/tsw/3848']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Investigation Into the Mechanical Properties of Rapid Manufacturing Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59f8a631-503d-4abd-a5a4-7c97b8525122/download,,"During the past few years, there has been a move to convert Rapid Prototyping (RP)
processes into Rapid Manufacturing (RM) machines to produce end-use parts for different
industries. However, in order to make Rapid Manufacturing possible, there is a need for
designers to have comprehensive information relating to the mechanical properties of new
materials at different intervals of ageing, temperature and humidity. This is in order for them
to have confidence in specifying the materials in their designs.
This paper will discuss the progress of the Design for Rapid Manufacture project that is
currently being undertaken at Loughborough University, and give details of the mechanical
properties of new range of Stereolithography (SL) materials that are currently being
extensively evaluated.","This project is funded by the UK Engineering and Physical Science Research Council
(EPSRC).",,,,,
"['Zhao, Xiayun', 'Rosen, David W.']",2021-10-12T20:48:09Z,2021-10-12T20:48:09Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88737', 'http://dx.doi.org/10.26153/tsw/15671']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Exposure Controlled Projection Lithography', 'direct metal deposition', 'process control', 'advanced control', 'backstepping control', 'mask projection stereolithography', 'evolutionary cycle-to-cycle', 'adaptive neural network']",Investigation of Advanced Process Control Methods for Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59c73655-69bd-49fb-94d3-0b8056ee3731/download,University of Texas at Austin,"The DMD based Exposure Controlled Projection Lithography (ECPL) process has
promising applications in fabrication of microfluidics and micro optics components. Unlike
a conventional layer-stacking projection stereolithography process, ECPL cures a 3D feature
by projecting radiation through a stationary, transparent substrate by varying exposure
patterns and durations implemented by a sequence of DMD bitmaps. Due to the
unavailability of an in situ metrology for cured part dimensions, unmeasurable time-varying
disturbances such as oxygen inhibition and light source fluctuations, and the complex
chemical & physics interactions in photopolymerization, a common practice in
stereolithography process planning is to use experimental characterization and statistics
models in an open-loop mode, which yields poor accuracy. This paper reviewed existing
process control methods for ECPL and defined a need for advanced control methods. As a
first proposal for advanced control methods to mask projection stereolithography, the paper
surveyed relevant processes and put forward a hierarchical framework of advanced control
methods for ECPL, including evolutionary cycle-to-cycle (EC2C) and adaptive neural
network (ANN) backstepping control methods. The goal is to identify some advanced
control methods, which are capable of tracking the process dynamics by online updating the
model parameters with real-time measurement feedback. Such closed-loop control methods
are promising to be able to improve the process precision and robustness.",,,,,,
"Yang, Li",2021-11-04T19:18:33Z,2021-11-04T19:18:33Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90007', 'http://dx.doi.org/10.26153/16928']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D periodic cellular structure', 'uniaxial stress', 'anisotropy', 'investigation', 'mechanical property']",An Investigation of Anisotropy off 3D Periodic Cellular Structure Designs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e797c20d-57d0-470b-92c0-043400e13a30/download,University of Texas at Austin,"In the design of periodic cellular structures, there exist various isotropic unit cell designs
that possess identical theoretical mechanical properties along three or multiple principal symmetry
directions. Although such definition of “isotropy” differs from the traditional definition that is used
for solid materials, it is often considered to represent the equivalent design implications in many
applications. In this study, the mechanical properties of various 2D and 3D periodic cellular
structures under uniaxial stress along different non-principal directions were investigated. The
relationships between the cellular unit cell geometries, structural size, loading orientation and the
mechanical properties of the cellular structures made of perfect elastic-plastic material were
discussed, which provide insights into the future design of cellular structures when utilizing
homogenization treatments.",,,,,,
"['Li, Longmei', 'Sun, Qian', 'Bellehumeur, Celine', 'Gu, Peihua']",2019-10-24T18:00:03Z,2019-10-24T18:00:03Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77411', 'http://dx.doi.org/10.26153/tsw/4500']",eng,2002 International Solid Freeform Fabrication Symposium,Open,FDM Process,Investigation of Bond Formation in FDM Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6c824d90-1f1b-49d0-a860-f0bf7e007233/download,,"FDM process fabricates prototypes by extruding a semi-molten filament through a heated
nozzle onto a platform. The semi-molten material solidifies with the neighboring material
diffusely after deposition. The bonding quality among ABS filaments in FDM2000 process
determines the integrity and mechanical property of resultant prototypes. This paper describes
heat transfer analysis of the FDM process. Sintering experiments were carried out to evaluate
qualitatively the dynamics of bond formation between polymer filaments. Quantitative
predictions of the degree of bonding achieved during the filament deposition process were made,
based on experimental data used in conjunction with heat transfer and sintering models.",,,,,,
"['Aduba, Donald C. Jr.', 'Feller, Keyton D.', 'Williams, Christopher B.']",2021-11-04T20:47:25Z,2021-11-04T20:47:25Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90024', 'http://dx.doi.org/10.26153/16945']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['ceramic', 'stereolithography', 'sintering', 'shrinkage', 'anisotropy', 'build orientation', 'scaffold', 'additive manufacturing']",An Investigation of Build Orientation on Shrinkage in Sintered Bioceramic Parts Fabricated by Vat Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1f080c58-212a-472c-b271-aa347030ffa9/download,University of Texas at Austin,"In this work, a vat photopolymerization (VP) additive manufacturing process fabricated bioceramic
cuboids at different build orientations to investigate their effects on post-sintering shrinkage and
associated physical properties. A suspension of β-tricalcium phosphate (TCP) in Autodesk PR 57
commercial photopolymer resin and dimethyl sulfoxide (DMSO) solvent was used to shape green
parts. Thermal treatment removed polymer from the green shape before sintering TCP at 1300 ◦C at 5
◦C/min. Part morphology, dimensional shrinkage, and mass loss after sintering were evaluated. Part
dimensions parallel to the build direction exhibited greater shrinkage compared to the other two
dimensions. Mass loss was independent of build orientation. This paper is the first to investigate the
relationship between build orientation and post-sintering shrinkage of bioceramic structures shaped by
VP. In this work, an understanding of printing ceramic suspensions, and accounting for dimensional
ceramic part shrinkage with respect to build orientation is gained to help guide print parameter
selection to improve part fidelity and performance.",,,,,,
"['Yan, Lei', 'Hill, Leon', 'Newkirk, Joseph W.', 'Liou, Frank']",2021-11-04T15:36:40Z,2021-11-04T15:36:40Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89988', 'http://dx.doi.org/10.26153/tsw/16909']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['build strategy', 'processing parameters', 'mechanical properties', 'Ti-6Al-4V', 'hybrid manufacturing', 'design of experiment']",Investigation of Build Strategies for a Hybrid Manufacturing Process Progress on Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f58b95fb-7f96-4479-abbb-511f12517925/download,University of Texas at Austin,"The various processing parameters of a hybrid manufacturing process, including deposition
and machining, is being investigated with a Design of Experiment (DoE). The intent was to explore
the effect of different build strategies on the final part’s Vickers hardness, tensile test, fatigue life,
and microstructure. From this experiment, the processing parameters can be linked to various
mechanical properties. This will lead to the ability to create a combination of deposition and
machining parameters, which will result in improved mechanical properties.",,,,,,
"['Yap, Y.L.', 'Dikshit, V.', 'Lionar, S.P.', 'Yang, H.', 'Lim, J.C.', 'Qi, X.', 'Yeong, W.Y.', 'Wei, J.']",2021-10-27T21:52:50Z,2021-10-27T21:52:50Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89628,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fiber reinforced composites', 'multi-material 3D printing', 'inkjet printing']",Investigation of Fiber Reinforced Composite Using Multi-Material 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4d83c0f-f506-42aa-9cea-b890441e6f39/download,University of Texas at Austin,"Fiber reinforced composite materials have been commonly fabricated by laying and
curing the stiff and high strength fibers within tough matrix to enhance the elastic modulus.
The strength and elasticity of the fiber reinforced polymers are dependent on the intrinsic
mechanical properties of matrix and fiber, the fiber layup pattern as well as the volume
percentage of the matrix and fiber. In this paper, the effects of these factors on the 3D printed
fiber reinforced composite materials were investigated. The fiber reinforced polymers were
fabricated using multi-material inkjet printer with rubbery material as matrix and rigid strong
polymer as the fiber reinforcement. Two types of fiber layup configurations and fiber/matrix
volume ratios were designed for this study. The experimental result shows that both tensile
strength and elastic modulus of the fiber reinforced polymers could be largely enhanced by
varying the fiber/matrix ratio and layup pattern.",,,,,,
"['Francis, Romy', 'Newkirk, Joseph W.', 'Liou, Frank']",2021-10-13T19:24:00Z,2021-10-13T19:24:00Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88767', 'http://dx.doi.org/10.26153/tsw/15701']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Friction Stir Processing', 'Laser Metal Deposition', 'Ti-6Al-4V', 'grain size', 'surface modification']",Investigation of Forged-Like Microstructure Produced by A Hybrid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea8a7d03-aa7e-4be1-9e62-9ed144b70d1e/download,University of Texas at Austin,"Laser Metal Deposition (LMD) is an additive manufacturing technique for manufacturing
complex near net shaped components. The grain size of the typical deposition microstructure in
case of Ti-6Al-4V can range between 100µm-600µm, which is much larger than that of forged-like microstructures. Friction Stir Processing (FSP) has been investigated as a method for
surface modification to form refined microstructure at the surface of the Ti-6Al-4V components
manufactured from the LMD method. Integration of FSP and LMD can greatly improve the
product properties. Friction stir processing of the laser deposited Ti-6Al-4V deposits was
performed and optimum processing parameters were obtained using this hybrid process. The
microstructure of the nugget regions obtained in the substrate weld, stir over deposit and deposit
over stir experiments is presented. A much decreasing grain size was observed in the dilution
zone inside the nugget from the stir surface to the bottom of the dilution zone.",,,,,,
"['Zekovic, Srdja', 'Dwivedi, Rajeev', 'Kovacevic, Radovan']",2020-03-05T18:47:17Z,2020-03-05T18:47:17Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80141', 'http://dx.doi.org/10.26153/tsw/7162']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser-Based Direct Metal Deposition,An Investigation of Gas-Powder Flow in Laser-Based Direct Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b186b684-fd03-4d71-862a-3e11beecbd4e/download,,"Laser-Based Direct Metal Deposition (LBDMD) is a blown-powder laser deposition process
which can produce fully-dense and metallurgicaly sound parts by a layered manufacturing
method. Since a deposition head equipped with discontinuous radially symmetric nozzles has the
potential to be tilted without influence of the gravity on the powder stream shape, it can be used
for multi-axis deposition. The shape of the gas-powder stream with respect to the shape of laser
beam and the size of the molten pool, have a large influence on the size and shape of the buildup.
They determine the geometrical accuracy and the surface quality of the buildup. This paper
examines gas-powder flow from radially symmetric nozzles using computational fluid dynamics
method. For verification purpose the powder flow was investigated by a visualization method
and powder concentration distribution was analyzed using image processing technique. The
obtained results are in good agreement with numerical model.",,,,,,
"['Kriewall, Caitlin S.', 'Sutton, Austin T.', 'Leu, Ming C.', 'Newkirk, Joseph W.', 'Brown, Ben']",2021-10-27T21:19:28Z,2021-10-27T21:19:28Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89617,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'heat-affected powder', '304L']",Investigation of Heat-Affected 304L SS Powder and Its Effect on Built Parts in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c7af8059-0c57-4371-95d6-50e54506baa3/download,University of Texas at Austin,"Selective laser melting (SLM) is a powder bed based additive manufacturing process in
which a layer of powder is laid over the surface of a substrate and a laser with sufficient energy
is employed to selectively melt particles to build a part layer by layer. During the SLM process,
dark smoke was observed coming off of the powder bed surface where the laser was interacting
with powder. This phenomenon resulted from heat-affected powder that was visibly different
than the base powder. Since the concentration of the heat-affected powder differs throughout the
build chamber as a result of the recirculating argon gas flow, powder samples from different
regions were collected for analysis. The heat-affected powder samples were analyzed by
scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and x-ray
diffraction (XRD) in order to distinguish differences between the heat-affected powder and the
base 304L stainless steel powder. The influences of the heat-affected powder on the
microstructure and tensile properties of parts built in different areas of the build chamber are also
investigated.",,,,,,
"['McCleary, J.', 'Durand, N.', 'Castillo Perez, L.', 'Medina Zorrosa, G.', 'Garcia Chavira J.P.', 'Espalin, D.']",2024-03-26T21:13:53Z,2024-03-26T21:13:53Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124411', 'https://doi.org/10.26153/tsw/51019']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['in-situ monitoring', 'robocasting', 'ceramics', 'quality control']",INVESTIGATION OF INSTRUMENTING ROBOCASTING PRINTER FOR CERAMIC SLURRIES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c72edbf9-1eb8-4d08-b14b-eb3f1e1fe20b/download,University of Texas at Austin,"Robocasting has multiple steps from ceramic slurry preparation to sintering that can impact
the end part quality. In-situ monitoring and process controls can aid in minimizing differences in
the quality of printed parts. The study and impact of different parameters during the printing
process and a parameter database will improve the quality between green bodies and sintered
parts. This paper discusses implementation of a CMOS camera, dynamic pressure sensor, and 2D
laser scanner into a custom-built robocasting printer for in process monitoring. Single line beads
were printed and analyzed by measuring the dimensions and pressure changes during printing.
Results show that the printer with sensors detected the location of possible defects and changes in
printed samples but further investigation is needed to filter noise and collect conclusive data.",,,,,,
"['Stucker, Brent', 'Esplin, Carson', 'Justin, Daniel']",2019-12-05T18:28:11Z,2019-12-05T18:28:11Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78653', 'http://dx.doi.org/10.26153/tsw/5709']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Medical-Grade,An Investigation of LENS®-Deposited Medical-Grade CoCrMo Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38592c75-eaa1-4d8d-9739-133150168a8a/download,,"A series of deposition experiments using CoCrMo were performed using an Optomec
LENS®1
 machine. An analysis of hardness, microstructure, and wear trends of the deposited
alloys was undertaken in an attempt to determine the applicability of using LENS® to create
better materials for orthopedic implants. It was found that LENS®-deposited CoCrMo alloys
were harder than wrought materials, however initial wear tests indicated that LENS®-deposited
alloys were less resistant to abrasive wear than wrought alloys.",,,,,,
"['Hossein Sehhat, M.', 'Sutton, Austin T.', 'Newkirk, Joseph W.', 'Leu, Ming C.']",2021-12-06T21:59:23Z,2021-12-06T21:59:23Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90688', 'http://dx.doi.org/10.26153/tsw/17607']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['gas-atomized powder', 'water-atomized powder', '304L', 'stainless steel', 'mechanical properties', 'laser powder bed fusion']",Investigation of Mechanical Properties of Parts Fabricated with Gas- and Water-Atomized 304L Stainless Steel Powder in the Laser Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0372a21b-0d73-44c1-9bc6-7b762e106bc4/download,University of Texas at Austin,"The use of gas-atomized powder as the feedstock material for the Laser Powder Bed Fusion
(LPBF) process is common in the Additive Manufacturing (AM) community. Although gas-atomization produces powder with high sphericity, its relatively expensive production cost is a
downside for application in AM processes. Water atomization of powder may overcome this
limitation due to its low-cost relative to the gas-atomization process. In this work, gas- and
water-atomized 304L stainless steel powders were morphologically characterized through
Scanning Electron Microscopy (SEM). The water-atomized powder had a wider particle size
distribution and exhibited less sphericity. Measuring powder flowability using the Revolution
Powder Analyzer (RPA) indicated that the water-atomized powder had less flowability than the
gas-atomized powder. Through examining the mechanical properties of LPBF fabricated parts
using tensile tests, the gas-atomized powder had significantly higher yield tensile strength and
elongation than the water-atomized powder, however, their ultimate tensile strengths were not
significantly different.",,,,,,
"['Ploetz, M.', 'Heckmeier, F.', 'Kirchebner, B.', 'Volk, W.', 'Lechner, P.']",2024-03-26T21:15:24Z,2024-03-26T21:15:24Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124412', 'https://doi.org/10.26153/tsw/51020']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['material jetting', 'liquid metal jetting', 'coppor alloys', 'multi-material parts']",INVESTIGATION OF MULTI-MATERIAL LIQUID METAL JETTING WITH COPPER MATERIALS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19ba36ec-e37b-4315-9331-c620d1b7509c/download,University of Texas at Austin,"Technical parts are typically subject to various requirements that may conflict with each
other. Multi-material parts can be a way to overcome such conflicting goals. Liquid Metal Jetting
(LMJ) can be a promising additive manufacturing process for the production of multi-material
copper parts with high geometric complexity. Since LMJ builds up a part droplet by droplet, there
are no mixed powders after printing. In addition, LMJ offers the possibility of changing materials
from droplet to droplet. In previous studies, we have shown that it is possible to produce copper
alloy parts using LMJ. In this work, we produced multi-material copper specimens at different
process parameters to investigate the manufacturing of multi-material copper parts. The
investigations show that the quality of the compound and the microstructure depend significantly
on the thermal process parameters used.",,,,,,
"['Lewis, Adam', 'Katta, Nitesh', 'McElroy, Austin', 'Milner, Thomas', 'Fish, Scott', 'Beaman, Joseph']",2021-11-08T22:57:07Z,2021-11-08T22:57:07Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90067', 'http://dx.doi.org/10.26153/tsw/16988']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['optical coherence tomography', 'nylon 12 powder', 'imaging depth', 'imaging', 'selective laser sintering']",Investigation of Optical Coherence Tomography Imaging in Nylon 12 Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b72624c2-eb9a-487f-b5d2-9025cd2cd51e/download,University of Texas at Austin,"Optical Coherence Tomography (OCT) has shown promise as a new process sensor in
selective laser sintering (SLS) which can yield depth resolved data not attainable with
conventional sensors. However, OCT images of nylon 12 SLS parts and powder contain artifacts,
which have not been previously investigated in literature. These artifacts along with the highly
scattering nature of the SLS parts and powder limit the imaging depth, which decreases the
usefulness of OCT imaging. This study seeks to study the causes of the imaging artifacts and
proposes and investigates methods to improve OCT imaging depth in nylon 12 powder.",,,,,,
"['Liu, Qingbin', 'Leu, Ming C.', 'Schmitt, Stephen M.']",2019-10-30T16:30:59Z,2019-10-30T16:30:59Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78186', 'http://dx.doi.org/10.26153/tsw/5275']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Prototyping,Investigation of Part Accuracy and Surface Roughness in Rapid Freeze Prototyping Based Investment Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8cf9c24e-ed56-4dc3-ad48-a4986a043ce4/download,,"The study as described in this paper is aimed at investigating the dimensional accuracy
and surface finish of metal parts made by investment casting with ice patterns generated by rapid
freeze prototyping. The process of investment casting with ice patterns is described and contrast
with conventional investment casting with wax patterns is made. The selection of binder material
for ceramic slurries and the need for an interface agent to separate the ice pattern from the
ceramic slurry in the mold making process are discussed. The accuracy and surface finish of ice
patterns and of the metal castings are presented and discussed. The parts used in this
investigation include cylinders with vertical and slant walls and a turbine impeller.","The authors gratefully acknowledge the financial support from the National Science
Foundation grants (DMI-0128313 and DMI-0140625) and the Research Board of University of
Missouri at Rolla.",,,,,
"[""O'Neill, W."", 'Sutcliffe, C.J.', 'Morgan, R.', 'Hon, K.K.B.']",2019-02-19T19:44:49Z,2019-02-19T19:44:49Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73437', 'http://dx.doi.org/10.26153/tsw/589']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['RPT', 'AIMS']",Investigation of Short Pulse Nd:YAG Laser Interaction with Stainless Steel Powder Beds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/184e4e62-d27b-4684-8d8e-8dd648361444/download,,"The development of metallic object construction has occurred at quite a pace over the last five years
with provision of many commercial techniques such as indirect and direct sintering of metal powder
beds. Although porosity is still a major problem for metal building a number of notable solutions
have been proposed, these include infiltration with low melting point alloys or direct fusing with
binary powder mixtures. Neither of these solutions allows one to build components without
compromising part strength and functionality. A process route is required that will allow solid parts
to be built from a single powder component without requiring time consuming downstream processes.
To this end, the present work examines the feasibility of using low energy high peak power laser
pulses from a Q-switched Nd: YAG laser to melt stainless steel powder fractions whilst examining the
melt displacement through high recoil pressures induced by rapid partial vaporisation of the powder
layer. The effect of laser pulse energy laser beam intensity, pulse frequency, and environmental gas
control on the integrity of the fused powder layer is presented.",,,,,,
"['Iyibilgin, O.', 'Leu, M.C.', 'Taylor, G.', 'Li, H.', 'Chandrashekhara, K.']",2021-10-13T19:39:16Z,2021-10-13T19:39:16Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88771', 'http://dx.doi.org/10.26153/tsw/15705']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'sparse-build tooling', 'rapid tooling', 'ULTEM', 'test coupons']",Investigation of Sparse-Build Rapid Tooling by Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2551c165-a8b6-47b8-b01a-3f3df6810ab5/download,University of Texas at Austin,"This paper describes the investigation of sparse-build tooling by Fused Deposition Modeling
(FDM®) aimed at rapid tooling with reduction in the amount of material. Sparse-build test
coupons having ULTEM as the material and varying air gap (sparse spacing), wall thickness, and
cap thickness were fabricated using the sparse and sparse-double dense build styles of the
Stratasys Fortus machine. The strengths and moduli of these coupons were measured in
compression and flexure tests. The strength/mass ratio and modulus/mass ratio were compared
among the various coupons, as well as with solid coupons, to investigate the effects of the two
build styles and the three sparse-build parameters. In addition, the effects of build direction and
raster orientation were also studied.",,,,,,
"['Yang, Li', 'Anam, Md Ashabul']",2021-10-18T20:27:29Z,2021-10-18T20:27:29Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89234,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['standard test part design', 'design efficiency', 'additive manufacturing']",An Investigation of Standard Test Part Design for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/32e6bf89-ddf6-4e68-96ca-27fd6f54af95/download,University of Texas at Austin,"This paper investigated the efficiency of the standard test part feature designs. Standard geometrical
dimensioning and tolerancing criteria were analyzed for their efficiency in representing process
characteristics of additive manufacturing (AM) processes. The design efficiency of the standard test part
proposed by NIST was evaluated, and based on the analysis, the part was redesigned. A minimum
characteristic set method was proposed to be used for future development of standard test part design.
In addition, it was suggested that feature dimensional effect as well as feature orientations are both
critical to geometrical quality evaluations, and therefore should be included in the feature design of the
standard test part.",,,,,,
"['Swank, M.L.', 'Strucker, B.E.']",2021-09-28T19:33:03Z,2021-09-28T19:33:03Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88162', 'http://dx.doi.org/10.26153/tsw/15103']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['support materials', 'Ultrasonic Consolidation', 'microstructures']",Investigation of Support Materials for Use in Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/52605998-1205-44bc-8b0c-5ecf90bd1db9/download,University of Texas at Austin,"This paper provides an overview of the need for supports and what characterizes a good
support material for Ultrasonic Consolidation. The goal is to look at a broad range of possible
support material choices and the benefits and drawbacks of each. By manually depositing
support materials during a build, each material is evaluated for its performance for three different
configurations: an enclosed pocket, freestanding rib, and open channel. These configurations
represent commonly seen features that often need to be built using Ultrasonic Consolidation, but
currently cannot be well constructed. The builds are constructed with 3003 Aluminum tapes at
room temperature. Microstructures are also studied to evaluate the consolidated material.",,,,,,
"['Poyraz, Ö.', 'Yasa, E.', 'Akbulut, G.', 'Orhangül, A.', 'Pilatin, S.']",2021-10-20T20:52:02Z,2021-10-20T20:52:02Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89359,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Direct Metal Laser Sintering', 'support structures', 'IN625', 'thin wall']",Investigation of Support Structures for Direct Metal Laser Sintering (DMLS) of IN625 Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4699bea2-492b-449e-b15b-6e908586bc8b/download,University of Texas at Austin,"Along with the increased application of additive manufacturing (AM) in the aerospace
industry, a better understanding of different aspects for the technique has become necessary to
fulfill the high demands of reliability and robustness. The ability to introduce very complex,
even internal, features into part design with AM appeals everyday many design engineers to
this new group of technologies. In this respect, new design rules for AM are being researched,
developed and updated day-to-day. Although, it is commonly stated that AM offers limitless
geometrical complexity, there are some limits of the technology. For Direct Metal Laser
Sintering (DMLS), a metal powder fusion AM process, one of the major limitations in the
geometrical freedom offered by AM is the overhang surfaces which necessitates melting on
loose powder and lead to dross formation, distortions, curling, etc. Support structures to be
built together with the target part thus become necessary and critical to avoid such undesired
results and moreover to facilitate a uniform heat dissipation. Design of the support structures
which are easy to apply and remove is therefore among the important research topics in AM.
The compromise in the design of support structures roots from the fact that the support
structures must be strong enough to connect the part to provide resistance for curling up and
they are desired to be loose enough to be easily removed. In addition, redundant use of
support structures increases the amount of material spent, production time as well as postprocessing efforts. This paper presents an investigation of different support structure designs;
applied onto a thin-walled IN625 part, manufactured using DMLS.",,,,,,
"['Karnati, S.', 'Axelsen, I.', 'Liou, F.F.', 'Newkirk, J.W.']",2021-10-27T21:07:51Z,2021-10-27T21:07:51Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89614,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'tensile properties', 'gage lengths', '304L']",Investigation of Tensile Properties of Bulk and SLM Fabricated 304L Stainless Steel Using Various Gage Length Specimens,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df93c13e-57cc-45f0-92bb-7f7c909b0c9d/download,University of Texas at Austin,"The complex solidification dynamics and thermal cycling during Selective Laser Melting
process is expected to result in non-equilibrium material characteristics. There is an essential
need for characterization techniques which are critical towards the estimation of anisotropies.
The current investigation is targeted towards establishing tensile testing methodologies and their
relation to differing gage lengths. Dog-bone shaped specimen designs with gage lengths of 1”,
0.3” and 0.12” were employed in this research. The characterization was performed on hot
rolled-annealed 304 stainless and SLM fabricated 304L stainless. It was theorized that smaller
gage length specimens would be instrumental in mapping material property anisotropy at a better
spatial resolution. The ultimate tensile and yield strength data were used to identify the material
property distribution and assess the anisotropy. The material property distributions were used to
successfully assess the testing methodologies and material characteristics.",,,,,,
"['Kong, C.Y.', 'Soar, R.C.', 'Dickens, P.M.']",2019-10-23T14:35:22Z,2019-10-23T14:35:22Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76748', 'http://dx.doi.org/10.26153/tsw/3837']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Ultrasonic,An Investigation of the Control Parameters for Aluminum 3003 under Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13be314c-694c-45fa-a52f-451dc58153bf/download,,"In this article, we investigate an innovative solid-state welding technique called Ultrasonic
Consolidation (UC) that is being developed as a freeform process for the layered fabrication
of aluminium tapes. UC involves the use of high frequency, low amplitude mechanical
vibrations that induce combined static and oscillating shear forces to produce elastic-plastic
deformation at the work-piece interface. This tends to break up and disperse aluminium
oxide and permits atomic diffusion to occur. The work centres on material characterisation
of aluminium tapes for aerospace and tooling applications. This paper will look at the
mechanical properties of aluminum 3003 specimens prepared by UC using different control
parameters that will lead to the determination of a general process window.",,,,,,
"['Basak, Amrita', 'Das, Suman']",2021-10-26T20:05:02Z,2021-10-26T20:05:02Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89571,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'scanning laser epitaxy', 'nickel-base', 'superalloys', 'rené N5', 'elemental segregation']",An Investigation of the Dendritic Segregation in Single-Crystal René N5 Fabricated Through Scanning Laser Epitaxy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/804731de-b256-4d88-a6b9-f5c5d305dc53/download,University of Texas at Austin,Dendritic segregation in single-crystal nickel-base superalloy René N5 was investigated in the present study.,This work is sponsored by the Office of Naval Research through grants N00014-14-1-0658.,,,,,
"['Elliott, A.M.', 'Ivanova, O.S.', 'Williams, C.B.', 'Campbell, T.A.']",2021-10-07T14:51:09Z,2021-10-07T14:51:09Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88468', 'http://dx.doi.org/10.26153/tsw/15405']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'quantum dot', 'nanoparticles', 'photopolymer resin', 'PolyJet', 'direct 3D printing']",An Investigation of the Effects of Quantum Dot Nanoparticles on Photopolymer Resin for Use in PolyJet Direct 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53cb6e11-4ff3-474c-be09-4f312e8ae391/download,University of Texas at Austin,"The addition of quantum dot (QD) nanoparticles to additive manufacturing (AM) media
provides the opportunity to create artifacts with complex geometry that also have unique optical
characteristics. However, the addition of nanoparticles can significantly alter the rheology of a
material and make it difficult to process in an AM context. In this study, quantum dots were
added to a photopolymer resin in varying mass ratios to photopolymer, and their effects on the
viscosity, surface tension, and jetting ability of the suspension were investigated. Results show
that printability was not significantly affected by the presence of quantum dots in mass
concentrations less than or equal to 0.5%. The nanosuspensions were deposited via inkjet to
demonstrate the feasibility of creating optically-unique artifacts.",,,,,,
"['Orange, Abigail', 'Wu, Yan', 'Yang, Li']",2021-11-09T20:10:24Z,2021-11-09T20:10:24Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90152', 'http://dx.doi.org/10.26153/tsw/17073']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['fatigue strength', 'cellular structures', 'compression-compression cyclic loading', 'electron beam powder bed fusion', 'EB-PBF', 'additive manufacturing']",An Investigation of the Fatigue Strength of Multiple Cellular Structures Fabricated by Electron Beam Powder Bed Fusion Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cb093c43-8bf8-4e77-9f2a-fa4d0500af86/download,University of Texas at Austin,"In this study multiple cellular structures, including the re-entrant auxetic, the octet-truss,
and the BCC lattice, were evaluated for their relative performance of fatigue strength under
compression-compression cyclic loading. Various design variations with different dimensions
were fabricated via electron beam powder bed fusion (EB-PBF) additive manufacturing (AM)
process and experimentally tested. Initial S-N based fatigue strength characterization with the BCC
lattice shows significantly decreased fatigue strength of the cellular parts compared to the solid
samples. Cross-design comparison were consequently carried out using constant maximum stress
ratio level. The results indicate that the fatigue characteristics of the EB-PBF cellular structures
are not only dependent on their topology types but also their geometry dimensions.",,,,,,
"['Bodger, C.', 'Gnaase, S.', 'Lehnert, D.', 'Troster, T.']",2024-03-26T21:18:22Z,2024-03-26T21:18:22Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124413', 'https://doi.org/10.26153/tsw/51021']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Inconel 718', 'process parameters', 'additive manufacturing']",Investigation of the influence of process parameters on productivity in the LPBF process for the material Inconel 718,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43f5aaac-d740-4371-927c-e91b24748a25/download,,"The nickel-based alloy Inconel 718, which is used in aerospace technology, poses a great
challenge to conventional machining due to its high strain hardening and toughness. Here, the laser
powder bed fusion process (LPBF) offers an alternative with potential savings if sufficiently high
productivity can be achieved. Based on the parameter study carried out, starting from the SLM
Solutions standard parameters for the manufacturing of components, exposure parameters could be
developed to realize manufacturing with 120 μm and 150 μm layer thickness, with almost the same
geometric accuracy. For this purpose, the process parameters of laser power, focus diameter, hatch
distance and scan speed were varied. The negative defocusing of the laser showed a positive effect
on the density of the parts, realizing densities ≥ 99.94 %, with high dimensional stability and good
mechanical properties. Considering the reduced manufacturing time of up to 61 %, a significant
increase in productivity was achieved.",,,,,,
"Boivie, Klas",2019-10-22T18:29:34Z,2019-10-22T18:29:34Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76338', 'http://dx.doi.org/10.26153/tsw/3427']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Sintering,Investigation of the Liquid Phase Sintering of Size Range Composed Powder for SLS Application,Conference paper,https://repositories.lib.utexas.edu//bitstreams/428d1a38-25a8-4c84-8f6e-cb72e6b6e300/download,,"In order to find the constraints and limiting factors for the development of a series of
homogenous steel materials has three different aspects of such a material system been
investigated in relation to each other; the composition of powders, the formation of green bodies
and sintering in a vacuum furnace. It was found that particle size range intervals must be
optimised, not only in respect to maximum part precision and powder density but also to
interparticle friction and laser penetration. Sintering time and temperatures should be adapted to
particles shape and diffusion rates, as well as the possible evaporation of alloy components.
Furthermore should the fraction of melting phase be balanced between solubility of liquid agent
in base material and the wetting of solid particles as well as being integrated in the smaller sized
fraction of the powder composition. While these issues remain undetermined, the possibility for
parts of homogenous steel materials by SLS cannot be eliminated.",,,,,,
"['Cooke, A.L.', 'Folgar, C.E.', 'Folgar, L.N.', 'Williams, J.', 'Park, S.', 'Rosen, D.W.']",2021-10-12T18:18:05Z,2021-10-12T18:18:05Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88712', 'http://dx.doi.org/10.26153/tsw/15646']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['conformal lattice structures', 'cellular materials', 'laser sintering', '3D Systems Corporation', 'Georgia Institute of Technology']",An Investigation of the Material Properties of Laser Sintered Parts Incorporating Conformal Lattice Structures (CLS™) Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/661d8c33-4f58-4186-96f8-fa71d7e7a517/download,University of Texas at Austin,"Cellular materials, including foams, honeycombs, lattices, and similar constructions, offer
the key advantages of high strength-to-weight ratios and favorable energy absorption
characteristics. The concept of designed cellular materials enables customized material
placement to best suit the demands of specific applications or achieve particular performance
targets. The design, generation, and fabrication of conformal lattice structures via laser sintering
are at the center of the disruptive manufacturing technologies proposed by 3D Systems
Corporation. The primary work reported here is the maturation and mechanical testing of the
conformal lattice structure technology developed between 3D Systems Corporation and the
Georgia Institute of Technology.",,,,,,
"['Fu, Youheng', 'Zhang, Haiou', 'Wang, Guilan', 'Wang, Huafeng']",2021-11-02T15:33:40Z,2021-11-02T15:33:40Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89832,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'bainite steel', 'mechanical properties', 'micro rolling', 'welding']",Investigation of the Mechanical Properties on Hybrid Deposition and Micro-Rolling of Bainite Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed025d0d-be05-4d8e-ae37-566fd3da2441/download,University of Texas at Austin,"Wire and arc additive manufacturing (WAAM) is a novel technology with high
efficiency and low cost for mass popularity. Whereas, the lack of deposition accuracy
and microstructure performances are still restricting its ongoing development. In this
paper, hybrid deposition and micro-rolling (HDMR) process has been used to
eliminate the anisotropy in WAAM bainitic steel samples. For the problems of
deficient deformation and larger remelting area due to deeper penetration and higher
temperature gradient, an initially optimized micro-rolling morphology has been
proposed. The results show: the tensile strengths of finished part are 1275MPa,
1256MPa, 1309MPa for transverse (X), longitudinal (Y), perpendicular (Z) directions
respectively. The elongation of three directions are 17.4%, 16.6%, 17.7% respectively.
The impact toughness is 99J/cm2 and the average grain size reaches about 7μm.
Compared to the traditionally heavy rolling equipment, micro roller this paper used
has transformative cost advantage to achieve high values of comprehensive
mechanical properties.",,,,,,
"['Seefried, M.', 'Zaeh, M.F.']",2020-02-17T14:55:02Z,2020-02-17T14:55:02Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80002', 'http://dx.doi.org/10.26153/tsw/7027']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Indirect Metal Laser Sintering,Investigation of the Oven Process in Indirect Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7f975857-7ce4-45ed-82de-e59d8379d4d8/download,,"This paper deals with the optimization of Indirect Metal Laser Sintering. Different experimental
analyses have proven that the oven process is highly responsible for the part distortion. By means
of polished micrograph sections and thermogravimetric and dilatometric investigations, the oven
process has been divided into four main steps: polymer removal, solid-state sintering, infiltration
and liquid-phase sintering.
Further experiments were carried out at higher temperature phases of the oven process, using
modified process parameters.
The aim of this research is to improve the knowledge about the oven process. In another step, this
process will be simulated by means of finite element analysis in order to minimize the part
distortion.",,,,,,
"['Dörfert, R.', 'Zhang, J.', 'Clausen, B.', 'Freiße, H.', 'Schumacher, J.', 'Vollertsen, F.']",2021-11-18T01:04:14Z,2021-11-18T01:04:14Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90383', 'http://dx.doi.org/10.26153/tsw/17304']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['oxygen content', 'mechanical property', 'tool steel 1.2344', 'laser beam melting']",Investigation of the Oxygen Content of Additively Manufactured Tool Steel 1.2344,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5f1126b-8e8e-4282-bdad-d3e378f451d4/download,University of Texas at Austin,"Laser Beam Melting (LBM) offers a high design flexibility and the possibility to create complex metal
parts in small batch sizes efficiently. However, several questions regarding the mechanical properties are still not
conclusively clarified. In general, the remaining degree of porosity is regarded as major indicator on the parts
properties. Other properties such as the resulting residual stresses, the oxygen contents and possible contaminants
of the powder or the influence of humidity are less often taken into consideration and difficult to measure. In this
work, the mechanical properties for LBM generated specimens out of tool steel 1.2344 are investigated and
compared to conventionally fabricated material. The quasi-static properties are comparable to conventionally
fabricated materials, whereas a significant impact on the fatigue strength was observed together with a high
oxygen content of 569 ppm, with significant oxygen peaks that can be allocated to the fractured area.",,,,,,
"['Moritzer, E.', 'Hecker, F.']",2023-04-05T13:52:43Z,2023-04-05T13:52:43Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117775', 'http://dx.doi.org/10.26153/tsw/44654']",eng,2022 International Solid Freeform Fabrication Symposium,Open,raster lines,Investigation of the Process Parameters and Geometry Dependent Shrinkage Behavior of Raster Lines in the Fused Deposition Modeling Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83be408c-b915-433b-ba88-6c56169327bc/download,,"Additive Manufacturing processes are able to generate components from raw material 
(filament, powder etc.) without the need of tools or conventional machining. One of the most 
common Additive Manufacturing processes is the Fused Deposition Modeling (FDM). Here, a 
thermoplastic polymer filament is fed into a heated nozzle where the filament is plasticized. 
The plasticized material is then deposited, layer-by-layer onto the building platform or the 
already existing component structure in a defined way. Thermoplastic polymers show a material 
specific shrinkage induced by the cooling process. The recurring heat input by depositing 
adjacent strands results in a complex cooling situation which contributes to the non-uniform 
shrinkage of the component. In the investigations, first, a Design of Experiments (DoE) is 
carried out to determine the influence of selected process parameters on the shrinkage behavior 
of the raster lines. Following, the geometrical deviations of simple geometries under 
consideration of different process parameters are determined and analyzed.",,,,,,
"['Lombardi, John L.', 'Artz, Gregory J.', 'Popovich, Dragan', 'Vaidyanathan, Ranji']",2019-02-26T17:27:03Z,2019-02-26T17:27:03Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73490', 'http://dx.doi.org/10.26153/tsw/640']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['EFF', 'FDM']",Issues Associated with the Development of a Water Soluble Support Material for use in Extrusion Freeforming & Fused Depositon Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0fff1782-a8db-4ee5-8daf-aa18b9c02a5f/download,,,,,,,,
"['Park, Jae-hyoung', 'Rosen, David W.']",2019-10-23T15:27:22Z,2019-10-23T15:27:22Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76762', 'http://dx.doi.org/10.26153/tsw/3851']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Vapor Deposition,Issues in Process Planning for Laser Chemical Vapor Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f19e641d-db1f-41d8-8ed7-adb54bac2984/download,,"Laser Chemical Vapor Deposition (LCVD) is a promising rapid prototyping and
manufacturing process that deposits metals and ceramics by local heating of a substrate with a
laser. Even though many LCVD process planning characteristics are shared with those of more
common Solid Freeform Fabrication (SFF) technologies, LCVD process planning requires new
efforts due to its unique characteristics. Unlike a conventional Layered Manufacturing (LM)
technology that only builds a planar layer, LCVD can build conformal layers (conform to nonplanar substrates), thin walls, and fibers (rod-shape). This paper explores process planning issues
for LCVD in the context of its unique characteristics.","We gratefully acknowledge funding from NSF, grant DMI-0070429, and the support of
the member companies of the Georgia Tech Rapid Prototyping & Manufacturing Institute.",,,,,
"['Morvan, Stephane M.', 'Fadel, Georges M.']",2018-11-15T21:24:27Z,2018-11-15T21:24:27Z,1996,Mechanical Engineering,doi:10.15781/T2ZW19C2Q,http://hdl.handle.net/2152/70281,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['IVECS', 'FFF', 'water-tight']","IVECS, Interactively Correcting .STL Files in a Virtual Environment",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b49c0702-084d-425e-b48c-f8a87f122b14/download,,"Free Form Fabrication (FFF) machines transform objects merely existing as Os or
1s in a computer into a tangible object. FFF machines shift the paradigm of standard 2
Dimensional printers/paper printouts to 3 Dimensional printers/volumetric printouts (or 3D
hardcopies). Currently, this technology is weakened by the link between computers and FFF
machines: the .STL file, which contains a series oftriangles representing the skin ofthe object
to be prototyped. A prototype, reflecting precisely the evolution of a concept within a design
cycle and allowing a systematic inspection/verification, is essential. A system responding to
this need was designed at Clemson University for the inspection and the correction ofsuch a
file. IVECS, the Interactive Virtual Environment for the Correction of.STL files, is a tool that
allows minute surgery to be performed on faulty tessellated models. IVECS allows STL files
to be imported, tessellation errors to be detected and automatically or manually fixed. This
paper expands on the use of IVECS for the inspection and the correction of .STL files. It
extends the usefulness of the STL format by allowing designers to virtually prototype before
actually building a physical model, thus contributing to a shorter design cycle.",,,,,,
"['Xiong, Ruitong', 'Christensen, Kyle', 'Xu, Changxue', 'Huang, Yong']",2021-10-18T21:24:15Z,2021-10-18T21:24:15Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89250,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['bioprinting', '3D inket printing', '3D laser printing', 'organ printing', 'organ transplant']",Jet-Based 3D Printing of Biological Constricts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/23e3bd63-7b21-440f-aab8-d2cd7a805f07/download,University of Texas at Austin,"Organ printing is the layer-by-layer bottom-up fabrication of complex cellular
organization of native tissues or organs by bioprinting multiple cell types and other biomaterials
at designated positions. The rising success rate of transplants has resulted in a critical need for
more tissues and organs. Approximately 95,000 people are on the waiting list for new organs in
the U.S. alone, and some die every day waiting for transplants. Integrated with a better
understanding of multicellular self-assembly, bioprinting-based organ printing provides a
promising solution to the problem of organ donor shortage. While some major challenges in
bioprinting are biological such as endothelialization, vascularization, and accelerated tissue
maturation, there is a critical need to create scale-up technologies for the robotic fabrication of
hollow three-dimensional (3D) vascular constructs for use as the first step toward organ printing.
Both inkjet- and laser- based bioprinting technologies have been explored as enabling bioprinting
technologies, and complex constructs such as 3D vascular and vascular-like constructs have been
successfully fabricated.",,,,,,
"['Haffner, H.A.', 'Rangapuram, M.', 'Dasari, S.K.', 'Isanaka, S.P.', 'Chandrashekhara, K.', 'Buchely, M.F.', 'Newkirk, J.W.']",2024-03-26T16:34:28Z,2024-03-26T16:34:28Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124361', 'https://doi.org/10.26153/tsw/50969']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['Johnson-Cook damage model', 'finite element simulation', 'laser powder bed fusion', '304L stainless steel']",JOHNSON-COOK FAILURE MODEL FOR ADDITIVELY MANUFACTURED 304L STAINLESS STEEL PARTS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/64a8041b-eaed-4a51-a1b2-17822b63919a/download,University of Texas at Austin,"Laser powder bed fusion (LPBF) process is a type of additive manufacturing technique
which uses a powder bed to form complex metal parts in a layer-by-layer process. This study aims
to understand the damage initiation in the parts manufactured by LPBF process using 304L
stainless steel powder, which is widely used in numerous applications. The tensile specimens were
manufactured using 304LSS powder through LPBF. Tensile specimens with varying notches were
tested to calibrate the parameters of the constitutive Johnson-Cook failure model. To obtain the
strength parameters, the tensile tests were performed at different temperatures and strain-rates. The
material model developed was used in numerical simulation of the tensile tests and compared with
the experimental results.",,,,,,
"['Zhang, Xinchang', 'Chen, Yitao', 'Pan, Tan', 'Cui, Wenyuan', 'Li, Lan', 'Liou, Frank']",2021-11-17T23:44:50Z,2021-11-17T23:44:50Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90358', 'http://dx.doi.org/10.26153/tsw/17279']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['copper', 'stainless steel 304L', 'joining', 'direct metal deposition']",Joining of Copper and Stainless Steel 304L Using Direct Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a4664efa-3730-4868-99a7-142b08711af1/download,University of Texas at Austin,"In the current study, the feasibility of joining pure copper (Cu) and stainless steel 304L
(SS304L) through direct metal deposition process was investigated by material characterization.
Samples were analyzed in terms of microstructure, elemental distribution, and tensile testing.
Direct depositing pure copper on SS304L shows copper was mechanically rather than
metallurgical bonded with SS304L due to the poor dissolubility of iron in copper. Iron was diffused
into copper with a diluted distance of 1.5 mm and above that, pure copper deposits were obtained.
Columnar structure was observed at the copper region near the interface while the columnar grains
became finer away from the interface and finally, equiaxed structure was observed. Tensile testing
shows the yield strength and ultimate tensile strength of combined materials (copper and SS304L)
are 123 MPa and 250 MPa and samples fractured at the copper section with a ductile fracture
mechanism. The bi-material interface survived the tensile test. The yield strength and ultimate
tensile strength of as-fabricated pure copper are 95.02 MPa and 186.66 MPa, respectively.",,,,,,
"['Yasin, Mohammad Salman', 'Soltani-Tehrani, Arash', 'Poudel, Arun', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-26T14:06:20Z,2023-01-26T14:06:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117301', 'http://dx.doi.org/10.26153/tsw/44182']",eng,2022 International Solid Freeform Fabrication Symposium,Open,KPV,Key Process Variable (KPV) Variations and Their Impact on Defect Structure and Tensile Behavior of L-PBF Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3264e7ce-3bb5-44dc-bba2-f9af8f3313e3/download,,"The process variables used in laser powder bed fusion (L-PBF) influence the defect 
formation in fabricated parts. However, key process variables (KPVs) such as laser power, laser 
speed, and hatch distance may drift within their tolerances during service between calibrations. 
These variations can result in different defect contents in parts and, consequently, different 
mechanical properties. Therefore, this study investigates the effects of KPV drift on the porosity 
and tensile behavior of L-PBF Ti-6Al-4V. According to the original equipment manufacturer, 
EOS, the laser power and hatch distance were altered by ± 4% and ± 2.4%, respectively, to emulate 
the actual drift in KPVs. Porosity analysis and hardness tests on L-PBF Ti-6Al-4V parts showed 
no significant change. In addition, tensile tests illustrated no general trend for different KPV drift 
variations.",,,,,,
"['Buchanan, Ranger', 'Kumar Dasari, Jeevan', 'Fidan, Ismail', 'Allen, Michael', 'Bhattacharya, Indranil']",2023-03-27T19:55:28Z,2023-03-27T19:55:28Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117660', 'http://dx.doi.org/10.26153/tsw/44539']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Fused Filament Fabrication', 'Iron-PLA Filament', 'Magnetability', 'ANOVA', 'MANOVA']",Knowledge Base Development for Mechanical Properties and Energy Consumption of Iron-PLA Composite Filaments in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1f9cada4-1034-4e83-8189-5718dab8e5d9/download,,"Additive Manufacturing (AM) is one of the latest manufacturing processes where instead 
of cutting away from material or casting an object, as in Traditional Manufacturing (TM), one 
constructively adds material to create a required design. The benefits of AM allow for some 
designs that are impossible to be manufactured with TM methods. One of the most common AM 
processes is Fused Filament Fabrication (FFF), which utilizes layers of extruded materials to 
manufacture objects.  While the most common materials in 3D printing are plastics, some other 
materials like metals can also be used. Such metallic printers can be utilized to manufacture 
materials with added electrical properties in addition to structural strength. 
Today, several new filaments are developed, tested, and practiced to answer the growing 
fabrication needs of advanced manufacturing industry. Several new materials such as wood, 
carbon fiber, fiber glass, and Kevlar are added to filaments to create new composite ones. The 
beta-testing results of these new filaments have been analyzed to improve their properties and 
functionality. The goal of this research study is to develop a number of knowledge blocks to 
successfully produce Iron-PLA composite parts and analyze the mechanical and magnetic 
properties in addition to the energy consumption of the prints based upon print parameters.",,,,,,
"['Xu, F.', 'Wong, Y.S.', 'Loh, H.T.']",2019-03-06T18:05:23Z,2019-03-06T18:05:23Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73559', 'http://dx.doi.org/10.26153/tsw/701']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'RP&M technology']",A Knowledge-based Decision Support System for RP&M Process Selection,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b10799d-a79b-4e33-b5e4-af00e622384b/download,,"Due to the large variety of RP&M material/machines and the. strengths/weaknesses
associated with different RP&M processes, the decision·to select a suitableRP&M system
becomes increasingly difficult. This paper presents a knowledge-based approach for the selection
ofsuitable RP&M material/machine to meet specific. requirements ofRP&Mapplications. The
system receives input data on the CAD modelandthe user's specifications,andgenerates outputs
that provide the most appropriate combination ofRP&Mmaterial/machine.·Optimal orientations,
together with estimated manufacturing time and cost, are considered and given in the final
outcome to help the user make the choice.",,,,,,
"['Auth, C.', 'Borstell, D.', 'Anderl, R.']",2021-11-15T21:50:23Z,2021-11-15T21:50:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90282', 'http://dx.doi.org/10.26153/tsw/17203']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['material production', 'manufacturing phase', 'lifecycle', 'fused deposition modeling', 'additive manufacturing']",Knowledge-Based Material Production in the Additive Manufacturing Lifecycle of Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e482293-46d4-45c8-a2de-b1a585b6806a/download,University of Texas at Austin,"The additive manufacturing (AM) lifecycle starts with the material production. This
phase has an impact on the AM process and its quality. Nowadays, information concerning
material production is not connected to the manufacturing process or the manufactured
component. Increasing digitalization enables data acquisition, handling and management.
Nevertheless, an integrated data concept for all AM lifecycle phases has not been realized yet.
Using information collected during the material production to evaluate component quality and
process stability is a huge research gap. Therefore, this paper deals with establishing a data
connection between material production and manufacturing phase. Based on the explanation of
the AM lifecycle, the identification of key influence factors and their interdependence a concept
for a knowledge-based material production in the AM lifecycle of fused deposition modeling
is developed. To prove the rationale behind the knowledge-based approach the interdependence
between two exemplary key factors is then evaluated experimentally and the result is discussed.
The implementation and validation phases contain the sensor plan for the material extruder and
the experimental examination of the effects of filament diameter changes on product quality.",,,,,,
"Bernard, Alain",2019-03-08T17:38:27Z,2019-03-08T17:38:27Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73570', 'http://dx.doi.org/10.26153/tsw/712']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping process', 'optimization']",Knowledge-based system for choice of rapid prototyping process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ce1ddc5-38b8-4243-b0c2-15a3e8b3a688/download,,"This paper introduces a knowledge-based system for the
choice of rapid product development processes.
Rapid product development processes are not limited to layer-manufacturing machines, but they also
integrate CAD reverse engineering, indirect methods for metallic and plastic part manufacturing, etc...
Due to short delays, people have no time to test and compare different solutions of rapid product
development processes. Even if people have time, tests are time and money consuming. It is also very
difficult for somebody to know all about industrial technologies, and to be able to evaluate a multi-criteria
choice in a short time.
The aim ofthe proposed knowledge-based system is to generate, from the specification of parts or
tools, different alternatives of rapid product development processes, which can be discriminated and
optimized when considering a combination of the different specification criteria (cost, quality, delay,
etc...).",,,,,,
"['Feygin, Michael', 'Hsieh, Brian']",2018-04-17T16:27:10Z,2018-04-17T16:27:10Z,1991,Mechanical Engineering,doi:10.15781/T2PV6BQ54,http://hdl.handle.net/2152/64325,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Mechanical, Aerospace, and Nuclear Engineering Department', 'Laminated Object Manufacturing', 'LOM', 'CAD']",Laminated Object Manufacturing (LOM): A Simpler Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/95bf7a6d-8ea9-4a47-bc81-4a3dd320a8e4/download,,"With Laminated Object Manufacturing (LQM) process, three dimensional objects
are manufactured by sequentially laminating and cUtting two-dimensional cross-sections.
The.rnediumused.inLOMprocess isaQhesive-coatedsheet• materials.. As seen in Figure 1,
the sheetmateria.l carries the adhesive either on one sideQr both sides, or it cQntains the
adhesive ill itself, like woven composite material impregnated with bonding agent. The
adhesive,which can be pre-coatedonto>material or be deposited prior to bonding, enables
layers of sheet material to be attached to each other so as to construct a three-dimensional
object.",,,,,,
"['Pope, Matthew J.', 'Patterson, Mark C.L.', 'Zimbeck, Walter', 'Fehrenbacher, Mark']",2018-12-06T21:22:01Z,2018-12-06T21:22:01Z,1997,Mechanical Engineering,doi:10.15781/T2XP6VP98,http://hdl.handle.net/2152/71431,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['damage-critica', 'laminated']",Laminated Object Manufacturing of Si3N4 With Enhanced Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56a20f92-8691-423b-bebb-dd0d07ed07a1/download,,"The potential to fabricate near net-shape ceramic components of intricate shape is attractive
and offers considerable savings in cost and time. The laminated architecture inherent in many
Rapid Prototyping techniques can be utilized to enhance material properties by providing weak
interfaces at regular intervals, oriented microstructures, and functionally graded compositions. By
design and control of these variables it is possible to enhance the strength, toughness and
performance of components fabricated from structural ceramics. A range of oriented
microstructural features have been investigated in Laminated Object Manufacturing of Si3N4
materials. Changes in the mechanical properties can be related to specific architectures and
microstructural developments which took place during sintering.",,,,,,
"['Eyerer, P.', 'Keller, B.', 'Shen, J.']",2018-09-26T20:27:36Z,2018-09-26T20:27:36Z,1994,Mechanical Engineering,doi:10.15781/T2DF6KN7G,http://hdl.handle.net/2152/68594,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['RP Systems', 'stereolithography systems', 'low-power laser']",LAPS - Laser Aided Powder Solidification - Technology for the direct production of metallic and polymer parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed77102d-8d81-4dbd-a40d-9cfae70205f5/download,,"The prototypes of today's commercial available RP-Systems (e.g. StereolithographySystems)
are suitable mainly for designing and, if even, for restricted functional tests.
From this it can be concluded that for obtaining functional or technical prototypes one has
to use time- and cost-intensive downstream-technologies like investment casting. Because
of the economical aspects in industries there is a great demand for direct production of
functional and technical prototypes.
The present paper describes the activities and research results on the development
techniques based on laser induced solidification of powder materials for the direct
manufacturing ofmetallic parts. Also a various number of polymers, suitable for sintering
and remelting, are investigated and presented as functional materials for different
applications.",,,,,,
"['Spinnie, N.', 'Smith, D.E.']",2021-10-28T15:42:58Z,2021-10-28T15:42:58Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89666,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['large-scale fused deposition modeling', 'fused deposition modeling', 'bead geometry', 'processing parameters']",Large Scale Fused Deposition Modeling: The Effect of Processing Parameters on Bead Geometry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac20c0bc-8faa-4a04-bcea-6a90e32a4cc7/download,University of Texas at Austin,"This paper considers processing parameters that affect bead geometry in
large-scale Fused Deposition Modeling (FDM). A BAK ExOn8 single screw mini extruder is
used to deposit controlled thermoplastic beads on a custom made heated build platform
specifically design for studying bead deposition. This study considers nozzle height above the
build platform, extruder screw RPM, platform speed, and polymer type. Deposition is performed
using an unfilled commercial copolyester, unfilled ABS, and filled ABS with 13% short carbon
fibers. Bead cross sectional area and shape are measured to evaluate flow rate and melt
distortion. Of particular interest is the dependence of bead shape on the inclusion of short carbon
fibers. Shape metrics including horizontal and vertical swell, aspect ratio, and convexity ratio are
used to quantify the shape of the bead cross section. Measured results show significant
variability in cross section geometry, supporting the need for quantifying these effects in order to
create a successful large-scale system.",,,,,,
"['Nycz, A.', 'Adediran, A.I.', 'Noakes, M.W.', 'Love, L.J.']",2021-11-01T20:53:26Z,2021-11-01T20:53:26Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89746,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['large structures', 'metal additive techniques', 'large scale metal additive techniques', 'metal additive manufacturing', 'geometric limit']",Large Scale Metal Additive Techniques Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c1f35978-c5fc-41f3-80a4-bcb5c9258025/download,University of Texas at Austin,"In recent years additive manufacturing has made long strides toward becoming a main stream production
technology. Particularly strong progress has been made in large-scale polymer deposition. However, large scale
metal additive has not yet reached parity with large scale polymer. This paper is a survey of the metal additive
techniques in the context of building large structures. Current commercial devices are capable of printing metal
parts on the order of several cubic feet compared to hundreds of cubic feet for the polymer side. In order to
follow the polymer progress path many factors must be considered—potential to scale, economy, environment
friendliness, material properties, feedstock availability, robustness of the process, quality and accuracy,
potential for defects, and post processing as well as potential applications. This paper focuses on current state
of art of large scale metal additive technology with a focus on expanding the geometric limits.",,,,,,
"['Watson, N.D.', 'Meisel, N.A.', 'Bilén, S.G.', 'Duarte, J.', 'Nazarian, S.']",2021-11-18T18:40:45Z,2021-11-18T18:40:45Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90462', 'http://dx.doi.org/10.26153/tsw/17383']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['large-scale additive manufacturing', 'concrete structures', '6-axis', 'robotic arm', 'habitat construction']",Large-Scale Additive Manufacturing of Concrete Using a 6-Axis Robotic Arm for Autonomous Habitat Construction,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8378b15a-46f8-4cab-937b-e815344eed00/download,University of Texas at Austin,"Layer-by-layer construction of concrete through additive manufacturing allows for greater
design freedom in concrete construction compared to conventional casting methods. This has led
researchers to pursue a variety of potential system solutions to the enable the creation of
architectural-scale additively-manufactured concrete structures. One of the most common
approaches is through the extrusion of concrete patterned via a six-axis robotic arm. However,
while the use of a six-axis robotic arm can offer significant geometric advantages in the printing
of architectural-scale concrete structures, it also suffers from significant challenges that must be
addressed. In this paper, the authors discuss potential methods to address such challenges
associated with (1) minimizing travel moves in toolpath design, (2) expanding the achievable build
volume, and (3) inserting pre-fabricated components in a structure being printed. These solutions
are then demonstrated through the context of NASA’s 3D-Printed Habitat Challenge.",,,,,,
"['Shepherd, Jacob J.', 'Meisel, Nicholas A.']",2021-11-16T15:39:38Z,2021-11-16T15:39:38Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90317', 'http://dx.doi.org/10.26153/tsw/17238']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['suitable parts', 'part filtering', 'printable As-Is', 'easily redesigned for printing', 'not printable parts', 'large-scale additive manufacturing']",Large-Scale Identification of Parts Suitable for Additive Manufacturing: An Industry Perspective,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f659a8c2-22db-41aa-bcd0-7c848cc577c3/download,University of Texas at Austin,"Additive manufacturing (AM) has many potential benefits to the aerospace industry, especially
when low production quantities are required. These benefits range from lightweight and complex
geometries to reduced setup costs and lead time. One of the largest challenges to introducing AM
into an existing aerospace vehicle is identifying which parts are candidates to be printed. This
paper identifies a number of criteria that can be used to quickly filter parts into three categories:
Printable As-Is, Easily Redesigned for Printing, and Not Printable Parts. The criteria are also
broken into three tiers based on their level of impact on eliminating parts from the selection
process. As a demonstration of these criteria, a case study is performed on a suborbital rocket,
consisting of over a thousand unique parts. A flow chart is provided to guide the implementation
of the filtering criteria, as well as methods to adapt the criteria to different industries.",,,,,,
"['Boulger, Alex', 'Laughter, Tyler', 'Rhodes, Andrew', 'Mhatre, Paritosh', 'Tsiamis, Nikolaos', 'Hershey, Christopher', 'Romberg, Stian', 'Lindahl, John', 'Kunc, Vlastimil']",2021-11-30T20:35:28Z,2021-11-30T20:35:28Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90538', 'http://dx.doi.org/10.26153/tsw/17457']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['large-scale thermoset', 'pick and place', '3D printer', 'large-scale additive manufacturing']",Large-Scale Thermoset Pick and Place Testing and Implementation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38751810-74da-4eb1-b185-8a918d0d50b9/download,University of Texas at Austin,"Oak Ridge National Laboratory is developing the first commercially available medium to large-scale
thermoset additive manufacturing (AM) system with Magnum Venus Products (MVP). This 3D printer is
capable of fabricating large-scale thermoset components at room temperature with a build volume of 16’ x 8’ x
42’’. The thermoset extrusion process uses irreversible exothermic chemical reactions to form a cross-linked
SRO\PHU ௗ3ULQWLQJWKHUPRVHWVDWVXFKODUJHVFDOHVZLWKKLJKO\FXVWRPL]DEOHPDWHULDOVDWURRP
temperature provides huge opportunities for complex and smart tooling applications. Integrating a pick and
place actuator into this system will allow for the placement of heating/cooling channels as well as sensors to
monitor tooling health and heat distribution. The pneumatically-driven pick and place actuator is integrated into
the existing electrical and mechanical design and is controlled using custom M-code commands. The system is
comprised mostly of commercially available components, providing easy adoptability by future thermoset
systems.",,,,,,
"['Strauss, Joseph Tunick', 'Stucky, Michael J.']",2021-10-26T19:30:40Z,2021-10-26T19:30:40Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89565,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['powder', 'powder mixture', 'additive manufacturing']",Laser Additive Manufacturing Process of a Mixture of Iron and Nickel Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02731c71-23fc-4249-89b3-fcc1d585d5ec/download,University of Texas at Austin,"Laser-based powder bed additive manufacturing (AM) of metal powders uses pre-alloyed
powder, which limits the alloys available for processing. Other processes using metal powders
such as powder metallurgy (PM) (press and sinter and MIM (Metal Injection Molding)) and
welding use elemental powder mixtures to produce a wide variety of alloy compositions. This
study tests the ability of laser AM to produce a homogeneous alloy from a mixture of powders.",,,,,,
"['Zhang, Jun', 'Ruan, Jianzhong', 'Liou, Frank']",2019-09-23T15:52:44Z,2019-09-23T15:52:44Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75945', 'http://dx.doi.org/10.26153/tsw/3044']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Automation,Laser Additive Manufacturing Process Planning and Automation 243,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e8701380-0173-47bd-a292-587f6e69d90f/download,,"This paper presents a Laser Additive Manufacturing Process Planning (LAMPP) being developed at the University of Missouri-Rolla. The off-line planning recognizes difficult-to-build features from an STL file, selects optimal part orientation and building directions based on the skeleton information of the object geometry, and optimizes the sub-process sequences for deposition and machining. During the optimization of the subpart building processes, collaboration between the deposition process planner and the machining process planner is needed to check the deposition availability and machinability. As a result, tool paths for both the laser head and the machining head are automatically generated.",,,,,,
"['Franceschini, Robert', 'Napravnik, Lee', 'Mukherjee, Amar', 'Sankaranarayanan, Srikanth', 'Kar, Aravinda']",2018-11-28T19:21:13Z,2018-11-28T19:21:13Z,1997,Mechanical Engineering,doi:10.15781/T26W96V6W,http://hdl.handle.net/2152/70324,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'design hierarchy', 'layered fabrication']",Laser Aided Direct Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b198e0bf-ac1f-4f46-977c-55cf9031a19c/download,,"We describe a multilevel design hierarchy applicable to the VLSI-like layered manufacturing technology of Solid
Freeform Fabrication (SFF) called Laser Aided Direct Rapid Prototyping (LADRP). We discuss the interfaces
between the abstraction levels and the requirements of the standard languages needed for the interfaces. We
provide experimental verification for the thickness design rule and indicate other possible design rules applicable
to this process. We then present a software tool called a Slicer that takes a three-dimensional description of
a solid body and creates 2.5D layers for the SFF process. Our current implementation is based on a boundary
representation of solids described by the Unigrafix solid modeler.",,,,,,
"['Wang, Jinglei', 'Prakash, Sashikanth', 'Joshi, Yashodhan', 'Liou, Frank']",2019-10-22T17:57:41Z,2019-10-22T17:57:41Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76326', 'http://dx.doi.org/10.26153/tsw/3415']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Part Repair,Laser Aided Part Repair-A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/826c5c2e-a1fa-45b9-ab2c-b8fd4a9d4559/download,,"Laser aided part-repair is an emerging trend that has great potential for future industrial
applications. Part-repair technologies are currently used in repairing military and civilian
equipment. The focus of this paper is to review the current repair processes, which use the laseraided metal deposition technology. Many metal parts, which are worn by continual use, can be
restored to working condition by the deposition of metal with a laser and machining. This not
only extends the life of the part, but also, saves on cost. A comparison between various
processes, their parameters, efficiency, cost, and etc. are also presented. The process limitations,
materials, and areas that are best suited for each process are also discussed.","This research was supported by the National Science Foundation Grant Number DMI-9871185,
Missouri Research Board, and a grant from the Missouri Department of Economic Development
through the MRTC grant.",,,,,
"['Tandra, Gargi', 'Sparks, Todd Eugene', 'Barua, Shyam', 'Kulkarni, Nikhil P.', 'Liou, Frank']",2021-10-01T00:03:56Z,2021-10-01T00:03:56Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88302', 'http://dx.doi.org/10.26153/tsw/15243']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['gas diffusion layers', 'polymer electrolyte membrane fuel cells', 'metallic GDL', 'laser deposition']",Laser Based Rapid Manufacturing of Metallic Gas Diffusion Layers for PEM Fuel Cells,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c754e164-22e9-4c48-b35f-91ed7b5febda/download,University of Texas at Austin,"Gas Diffusion layers (GDL’s) are an essential component of Polymer
Electrolyte Membrane Fuel cells (PEMFC’s) which aid in thermal & electrical
conductivities, water management and act as backup layers for the membrane
electrode assemblies. This paper summarizes the effort to prototype metallic GDL
designs using a miniature laser deposition system developed at Missouri University
of Science & Technology. The pore sizes are controlled by masking the diverging
laser beam using stainless steel masks of varying sizes and shapes. The through
pore feature and further treatment of the GDL’s for hydrophobicity reduces the
water management issue and thereby increases the performance of the fuel cells.
The operational characteristics of the GDL can be optimized by understanding the
effect of the key parameters like fluid permeability, porosity, hydrophobicity and the
surface morphology.",,,,,,
"['Holla, Vijaya', 'Kopp, Philipp', 'Grundewald, Jonas', 'Praegla, Patrick M.', 'Meier, Christoph', 'Wudy, Katrin', 'Kollmannsberger, Stefan']",2024-03-26T17:08:57Z,2024-03-26T17:08:57Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124378', 'https://doi.org/10.26153/tsw/50986']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser beam shaping', 'beam shape optimization', 'Gaussian-shaped laser', 'metal additive manufacturing', 'powder bed fusion of metals']",Laser beam shape optimization: Exploring alternative profiles to Gaussian-shaped laser beams in powder bed fusion of metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/341fb9bd-2b21-4af1-b38b-897f2d8203b1/download,University of Texas at Austin,"Laser-based powder bed fusion of metals (PBF-LB/M) commonly utilizes Gaussian-shaped laser
beams characterized by a high intensity at the center. However, this type of profile leads to localized high temperatures and temperature gradients. When the laser power is increased beyond
a certain threshold, the temperature inside the melt pool can reach the boiling point, causing excessive metal evaporation, hydrodynamic instabilities, and undesired effects such as keyholing.
On the other hand, ring-shaped laser beams generate a more uniform temperature distribution but
tend to produce shallower, wider, and shorter melt pools with reduced resolution compared to the
Gaussian profiles. The deep, narrow, and elongated melt pools generated by the Gaussian shapes
still have advantages for increased precision in the PBF-LB/M processes. This contribution uses
numerical optimization to generate a new laser beam shape that also leads to a deep, narrow, and
elongated melt pool, similar to a Gaussian-shaped beam, while maintaining a lower and more uniform temperature distribution inside the melt pool. The resulting optimized laser profile lowers the
maximum laser intensity by 40 % without decreasing the total laser power compared to the Gaussian profile. The more uniform distribution of temperature with a peak value of just above 3 000 ◦C
indicates a conduction dominated process with less hydrodynamic and minimal evaporative effects.
This is expected to reduce the associated defects and improve the process stability",,,,,,
"['Lubiano, Gigliola', 'Ramon, Jorge A.', 'Magee, Johnathan']",2019-09-23T17:20:23Z,2019-09-23T17:20:23Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75981', 'http://dx.doi.org/10.26153/tsw/3080']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Bending,Laser Bending of Thin Metal Sheets by Means of a Low Power CO2 Laser 537,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0756fafb-b174-46d6-a900-617f4193435d/download,,"An experimental study of the deformation phenomena during laser bending of 0.5 mm metal sheets is presented here. The thermal gradient mechanism, i.e. ratio of the laser beam diameter to the sheet thickness less than unity, was used to bend the samples. The sheets, which are made of 304 stainless steel, 1100 aluminum and 1010 carbon steel, were scanned with a
focused CO2 laser beam for several times. Optical power of the laser ranged from 64 to 95 W and its maximum traverse speed was 15 mm/s. Results are presented as plots of the bending angle vs. number of scans (i.e. 2θ-N curves). Understanding of this novel forming process is crucial in order to find applications for it in the rapid prototyping field.",,,,,,
"['Yeung, Ho', 'Grantham, Steven']",2023-01-27T14:23:20Z,2023-01-27T14:23:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117339', 'http://dx.doi.org/10.26153/tsw/44220']",eng,2022 International Solid Freeform Fabrication Symposium,Open,powder bed fusion,Laser Calibration for Powder Bed Fusion Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4901aa54-39d9-48aa-bfe6-d57acf0f4ce4/download,,"Laser powder bed fusion systems use a high-power laser, steered by two galvanometer 
mirrors to scan a pattern on metal powder layers. The laser spot size, position, and synchronization 
between the laser power and position are critical to the build quality. This paper describes in-situ 
calibration techniques utilizing a digital camera to image the attenuated laser beam directly. The 
laser spot size is measured using laser beam images taken by the camera at different heights. The 
laser position measurement involves commanding the galvanometer motor to scan through a grid 
of points on the camera sensor. The synchronization of laser power and position is verified by 
observing the intersections of the adjacent scan vectors. These methods provide not only a tool for 
calibration but also insights into the laser control for the laser powder bed fusion additive 
manufacturing process.",,,,,,
"['Lightman, Allan', 'Han, Gyoowan']",2018-11-14T17:25:27Z,2018-11-14T17:25:27Z,1996,Mechanical Engineering,doi:10.15781/T27H1F64S,http://hdl.handle.net/2152/70246,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'thermal degradation', 'casting']",Laser Cutting of Ceramic Composite Layers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d029bc8e-1496-4d76-a53f-dbb607fbce0f/download,,"The Laminated, Object Manufacturing (LOM) process lends itself to use of a variety of
materials that can be delivered in sheet format. Studies are underway to investigate the use of
monolithic and fiber reinforced (composite) ceramic tapes. The laser cutting process presents a
challenge due to the refractory properties of the fibers and, in some cases, their high thermal
conductivity. The cw CO2 laser's thermal degradation process currently used is not suitable for
these materials. The evaluation of potential alternative lasers has focused on pulsed systems that
use either photoablation together with thermal processes or thermal shock with thermal
degradation. We will describe preliminary results achieved in our study of the photoablation
process using a copper-vapor laser.",,,,,,
"['Li, Xiaoxuan', 'Wang, Jiwen', 'Shaw, Leon L.', 'Cameron, Thomas B.']",2020-02-20T18:32:51Z,2020-02-20T18:32:51Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80036', 'http://dx.doi.org/10.26153/tsw/7058']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Multi-Material Laser Densification,Laser Densification of Extruded Dental Porcelain Bodies in Multi-Material Laser Densification (MMLD) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2cf053f9-8d03-469a-8d96-f76a901b9374/download,,"In this study commercial dental porcelain powder was deposited via slurry extrusion and
laser densified to fabricate dental restorations in a Multi-Material Laser Densification (MMLD)
process. The processing conditions for laser densification of single lines and closed rings were
investigated in order to avoid warping and cracking. Multi-layer rings were also investigated to
study the dependence of bonding between layers on the laser densification conditions. The laser
densified rings showed no warping, and good bonding between layers could be achieved when
the laser densification condition was selected properly. The mechanism to achieve porcelain
rings without warping and cracking is discussed. The understanding developed will pave the way
for fabricating a physical dental restoration unit.",,,,,,
"['Yang, Yu', 'Sparks, Todd', 'Ruan, Jianzhong', 'Ren, Lan', 'Liou, Frank']",2020-03-09T13:38:57Z,2020-03-09T13:38:57Z,8/23/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80176', 'http://dx.doi.org/10.26153/tsw/7195']",eng,2007 International Solid Freeform Fabrication Symposium,Open,"['Laser Aided Manufacturing Lab', 'Laser deposition', 'part comparison']",Laser Deposition Cladding On-Line Inspection Using 3-D Scanner,Conference paper,https://repositories.lib.utexas.edu//bitstreams/733de8e2-7037-48d2-92da-aed8b5f4d769/download,,"Laser deposition directly deposits metal cladding to fabricate and repair components. In
order to finish the fabrication or repair, 3-D shape of the deposition needs to be inspected, and
thus it can be determined if it has sufficient cladding to fabricate a part after deposition process.
In the present hybrid system in the Laser Aided Manufacturing Lab (LAMP) at the University of
Missouri - Rolla, a CMM system is used to do the inspection. A CMM requires point-by-point
contact, which is time consuming and difficult to plan for an irregular deposition geometry. Also,
the CMM is a separate device, which requires removal of the part from the hybrid system, which
can induce fixture errors. The 3-D scanner is a non-contact tool to measure the 3-D shape of laser
deposition cladding which is fast and accurate. In this paper, A prototype non-contact 3-D
scanner approach has been implemented to inspect the free-form and complex parts built by laser
deposition. Registration of the measured model and 3-D CAD model allows
the comparison between the two models. It enables us to determine if the deposition is sufficient
before machining.",,,,,,
"['Fessler, J.R.', 'Merz, R.', 'Nickel, A.H', 'Prinz, F.B.', 'Weiss, L.E.']",2018-11-09T16:12:09Z,2018-11-09T16:12:09Z,1996,Mechanical Engineering,doi:10.15781/T29Z90X7D,http://hdl.handle.net/2152/69928,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SDM', 'CAD', 'SFF']",Laser Deposition of Metals for Shape Deposition Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c471eccb-cc18-49ee-b74e-d5a84e5a4c90/download,,"A laser/powder deposition process has been added to the Shape Deposition Manufacturing system
at Stanford University. This process is more robust than previous SDM metal deposition
processes, consistently producing fully dense, near-net shape deposits with excellent material
properties Material is deposited by scanning the laser across a surface while injecting metallic
powders into the melt-pool at the laser focus. A number of parts have been produced with the
system, including an injection molding tool, multimaterial structures and simple mechanisms.
Currently research is being perfonned to improve the finish quality of the parts. One of the main
areas of research involves controlling thermal stresses which can lead to warpage and
delamination. Selective deposition techniques and the use of low coefficient of thennal expansion
materials such as INVARTM show promise for reducing defonnations caused by internal stresses.",,,,,,
"['Ruizpalacios, R.', 'Kyogoku, H.', 'Sriram, V.', 'Wood, K.L.', 'Beaman, J.J.']",2019-11-21T18:17:17Z,2019-11-21T18:17:17Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78554', 'http://dx.doi.org/10.26153/tsw/5610']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Direct-Write,Laser Direct-Write of Nanoporous Optical Coatings: Preliminary Results,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d67c4cbe-cdde-43aa-94ec-8c49abe5f2de/download,,,,,,,,
"['Liu, Z.C.', 'Ning, F.D.', 'Cong, W.L.', 'Zhang, H.C.']",2021-10-28T19:14:22Z,2021-10-28T19:14:22Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89673,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser engineered net shaping', 'energy consumption', 'laser power', 'scanning speed', 'powder feed rate']",Laser Engineered Net Shaping of Metal Powders: A Study on Energy Consumption,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f47064b2-1b29-46f1-a5fb-cb78399c6a02/download,University of Texas at Austin,"With the increasing awareness of environmental protection and sustainable manufacturing, the energy
consumptions and potential environmental impacts of laser additive manufacturing (LAM) technology has been
attracting more and more concerns. This paper firstly investigates the energy distributions of different modules
of laser engineered net shaping (LENS), studies the effects of input variables (laser power, scanning speed, and
powder feed rate) and kinds of powders on the overall energy consumption during laser deposition processes. The
Energy Consumption of Unit Deposition Volume (ECUDV, in J/mm3) is proposed as a measure for the average
applied energy per volume of deposited material. The experimental results suggest that the powder feed rate has
the largest effect on ECUDV, followed by scanning speed and laser power. When the geometry shaping is selected
as an evaluating criterion, AISI 4140 powder will cause the largest energy consumption per unit volume.",,,,,,
"['Kobryn, Pamela A.', 'Semiatin, S. Lee']",2019-09-20T15:19:16Z,2019-09-20T15:19:16Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75920', 'http://dx.doi.org/10.26153/tsw/3019']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Laser,Laser Forming of Ti-6Al-4V: Research Overview 58,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1105956f-4827-459c-a498-6aa8fc7d98da/download,,"Laser forming is a solid-freeform-fabrication process which is being investigated for
titanium-component manufacturing based on its cost-reduction potential. However, before it can
be transitioned to production, the relationships between processing parameters, input materials,
and deposit properties must be understood. In the present work, efforts were undertaken to
characterize these relationships. These efforts included a comparison of different laser-forming
processes, an investigation of the effect of processing parameters on deposit structure,
determination of microstructure evolution via laser-processing experiments and thermal FEM
modeling, and a study of texture/microtexture evolution. An overview of the results of this laserforming research are provided in this paper",,,,,,
"['Ramos, J.A.', 'Bourell, D.L.', 'Govindaraju, M.R.']",2019-10-18T17:15:13Z,2019-10-18T17:15:13Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76268', 'http://dx.doi.org/10.26153/tsw/3357']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Coatings,Laser Fusion Coatings of Functional Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a6be9a83-8f67-487f-ab45-b79f91e9ff8e/download,,"Surface characteristics of functional parts made by Solid Freeform Fabrication
techniques such as Selective Laser Sintering (SLS), Stereolitography Apparatus (SLA) or
other fabrication techniques can be enhanced by the application of multi-element based
laser fused coatings. Environmental protection and wear resistance, among other
properties can be achieved by pre-depositing a slurry over the surface of the parts,
followed by a high-speed scanning with a high power laser beam. Wetting of the part
surface by the molten slurry is a main concern in this coating process. Wetting
characteristics of molten slurry can be improved by the right combination of coating
constituents, laser processing atmosphere, and laser processing parameters. Coating
quality is also a critical issue to ensure good performance of the coatings especially for
environmental protection. This paper presents results obtained for carbon-carbon
composites coated with silicon-based slurries by laser fusion process. Criterion in
selecting the coating constituents, laser process conditions, and oxidation test results are
discussed.","The authors gratefully acknowledge the support of the Ballistic Missile Defense
Organization (BMDO) for this work. The research is being funded under the Small
Business Innovative Research (SBIR) Program and managed by the Wright-Patterson Air
Force Base, Dayton, Ohio.",,,,,
"Edinger, R.",2021-11-16T14:55:09Z,2021-11-16T14:55:09Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90302', 'http://dx.doi.org/10.26153/tsw/17223']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['beam focus', 'beam spot size', 'beam deflection', 'laser heating', 'electron beam gun', 'electron beam additive manufacturing']",Laser Heated Electron Beam Gun Optimization to Improve Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/89b02b8f-314b-4511-b618-20d3df005523/download,University of Texas at Austin,"Electron Beam Additive Manufacturing requires to improve electron gun characteristics to
become a highly competitive manufacturing process. Our work targets the optimization of
beam focusing to reduce the beam spot size, to improve the beam deflection system resulting
in higher positioning accuracy, to refine thermal stability by minimizing heat induced drifting
and to introduce a new powder delivery device which can be synchronized to beam parameters.
Heisenberg's uncertainty principle states that if a position of a particle is precisely known, its
momentum becomes less accurate and vice versa. Therefore, it will be required to conceive
gun parameters optimizing the balance of opposing laws. Our goal is to deliver an open
platform electron beam additive manufacturing machine which utilizes the results presented in
this paper.",,,,,,
"['Krantz, Justin T.', 'Lough, Cody S.', 'Brown, Ben', 'Yang, Jinyu', 'Go, David B.', 'Landers, Robert G.', 'Kinzel, Edward C.']",2024-03-26T21:20:55Z,2024-03-26T21:20:55Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124414', 'https://doi.org/10.26153/tsw/51022']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['in-situ monitoring', 'laser power bed fusion', 'spectroscopy', 'additive manufacturing']",Laser Induced Breakdown Spectroscopy for In-Situ Monitoring of Laser Powder Bed Fusion Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee7efcbf-99f5-4dcb-96ae-5aedf8206198/download,University of Texas at Austin,"A major challenge for laser powder bed fusion processes is identifying and addressing
flaws in the as-built part. In-situ monitoring of the magnitude of radiation emitted from the vicinity
of the melt pool largely corresponds to the temperature field. This has been correlated with the
local porosity and microstructure of the part. However, the composition of the part can also vary,
either because of processing conditions or differences in the powder. Spectroscopy has the
potential to resolve material composition because spectral lines corresponding to atomic species
present in the metal can be clearly observed. The line emission phenomena from ionization and
excitation in the vapor plume is limited under standard LPBF conditions. Laser induced breakdown
spectroscopy (LIBS) uses a pulsed laser to produce a localized plasma. This is demonstrated in
LPBF using an ultrashort pulsed (USP) laser coaligned to the continuous wave (CW) process laser.
The USP laser can be used to probe the melt pool and plume in-process, creating a plasma that is
independent of the process conditions. This probing process has minimal adverse effects on the
melt pool. LIBS can provide feedback about the local species content through time resolved
spectroscopy and provides the potential for voxelwise composition information to be obtained
from the material.",,,,,,
"['Berez, Jaime', 'Saldaña, Christopher']",2023-01-27T13:45:06Z,2023-01-27T13:45:06Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117330', 'http://dx.doi.org/10.26153/tsw/44211']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion (LPBF)', 'powder bed measurement', 'topography', 'laser line profiler', 'surface texture']",Laser Line Profile Scanning for Powder Bed Topography Measurement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44cf0b7b-5b4b-4212-a421-92ca87760c11/download,,"The metal additive manufacturing (AM) method of laser powder bed fusion (LPBF) relies 
upon the formation of uniform, densely packed, and defect free powder layers. The direct 
measurement of as-spread powder layer quality is challenging owing to the fine size of the powder 
bed features and limited selection of instruments which can assess the powder bed in-situ. This 
work assesses the fitness of a laser line profiling instrument in the topographical measurement of 
an LPBF system powder bed. Firstly, results which assess the minimum resolvable feature size are 
presented, which suggest the instrument can capture microscopic powder bed defects. The ability 
of the instrument to detect macroscopic powder bed defects is also shown. Measures of bed quality, 
based on areal surface texture analysis, are explored for their potential as process signals.",,,,,,
"['Gegel, M.', 'Nisbett, A.', 'Bristow, D.', 'Landers, R.G.']",2021-10-28T15:00:03Z,2021-10-28T15:00:03Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89659,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'laser line scanner', 'geometric profiles', 'Missouri University of Science and Technology']",Laser Line Scan Characterization of Geometric Profiles in Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4cbe7e61-d4e3-457c-aeaa-5d38c585d305/download,University of Texas at Austin,"Laser Metal Deposition (LMD) is an additive manufacturing process in which material is deposited
by blowing powdered metal into a melt pool formed by a laser beam. When fabricating parts, the substrate
is subjected to motion control such that the melt pool traces a prescribed path to form each part layer.
Advantages of LMD include relatively efficient powder usage, the ability to create functionally-graded
parts and the ability to repair high-value parts. The process, however, is sensitive to variations in process
parameters and a need for feedback measurements and closed-loop control has been recognized in the
literature [1, 2]. To this end, a laser line scanner is being integrated into an LMD system at the Missouri
University of Science and Technology. Measurements from the laser line scanner will provide the feedback
data necessary for closed-loop control of the process. The work presented here considers characteristics of
the laser line scanner as it relates to scanning LMD depositions. Errors associated with the measurement
device are described along with digital processing operations designed to remove them. The parameter bead
height is extracted from scans for future use in a closed-loop control strategy.",,,,,,
"['Kyogoku, Hideki', 'Ramos, Jorge A.', 'Bourell, David L.']",2019-11-21T18:53:05Z,2019-11-21T18:53:05Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78571', 'http://dx.doi.org/10.26153/tsw/5627']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Ti-Ni Shape,Laser Melting of Ti-Ni Shape Memory Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/94e4c302-0fc8-450f-9393-c57da1a203cf/download,,"The applicability of laser melting in fabrication of Ti-Ni shape memory alloy was
investigated experimentally. Elemental powders of Ti and Ni and mechanically alloyed (MA)
TiNi powder were used to fabricate specimens. The effects of powder characteristics on the
microstructure and shape memory characteristics of the alloy were examined. The morphology
and microstructure of the laser-melted specimens were varied with fabrication conditions. Parts
fabricated from elemental powders exhibited a shape memory effect, but those from MA powder
did not exhibit it, although the latter showed more homogeneous microstructure than the former.",,,,,,
"['Azizi, Arad', 'Schiffres, Scott N.']",2021-11-16T14:59:50Z,2021-11-16T14:59:50Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90304', 'http://dx.doi.org/10.26153/tsw/17225']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['material bonding', 'powder bed fusion', 'selective laser melting', 'SLM', 'laser material processing', 'graphite-metal bonding']",Laser Metal Additive Manufacturing on Graphite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/494d8878-91d4-46c0-9558-86672599bbd9/download,University of Texas at Austin,"Metal powders are typically directly fused to a metal substrate of similar composition in
metal powder-bed fusion additive manufacturing. This work presents a process for printing a metal
alloy directly on graphite, rather than a metal platform. This technology has attractive applications
to heat transfer, as this process can be used to directly print heat sinks or heat exchangers on
pyrolytic graphite. The heat transfer applications of metal-pyrolytic graphite are enormous, as
pyrolytic graphite has the second highest thermal conductivity (>1700 W/m-K at room
temperature) of any bulk material, with only expensive diamond exceeding it. Bonding of common
metal alloys used in additive manufacturing and graphite are relatively weak and possess high
contact angles. However, by using the proper interlayer material, wettability and reactivity of the
graphite substrate with metal powder can increase drastically. The alloys that can typically bond
to graphite require extended times at elevated temperatures (minutes to hours), while this study
demonstrates rapid bonding (~100 µs).",,,,,,
"['Karnati, S.', 'Sparks, T.E.', 'Liou, F.', 'Newkirk, J.W.', 'Taminger, K.M.B.', 'Seufzer, W.J.']",2021-10-20T22:37:05Z,2021-10-20T22:37:05Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89378,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['functionally gradient materials', 'copper-nickel', 'Laser Metal Deposition']",Laser Metal Deposition of Functionally Gradient Materials from Elemental Copper and Nickel Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ae73da4f-e234-4d42-8ceb-b8a935e1fa6b/download,University of Texas at Austin,"This work deals with the planning and fabrication of a functionally gradient copper-nickel composition via Laser Metal Deposition (LMD). Various compositions of copper and
nickel were made by blending different weight percentages which were then sequentially
deposited to fabricate functionally gradient copper-nickel thin-wall structures. Analyses were
performed by sectioning the thin-wall samples for metallographic, hardness, X-ray diffraction
(XRD) and Energy Dispersive X-ray Spectroscopy (EDS) studies. The fabrication was studied
for identifying and corroborating the deposited compositions and their corresponding gradients.
XRD analyses were performed to identify the crystal structure of the deposit. EDS analysis was
instrumental in identifying the variation in composition and realizing the gradient in between
compositions. Consequences of using different laser beam intensity profiles and varying laser
power duty cycles were realized by analyzing the copper-nickel concentration trends obtained
from EDS analyses. Hardness testing was successful in capturing the decreasing trends in
strength with decreasing nickel concentration.",,,,,,
"['Streek, A.', 'Regenfuss, P.', 'Ebert, R.', 'Exner, H.']",2020-03-11T15:34:38Z,2020-03-11T15:34:38Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80254', 'http://dx.doi.org/10.26153/tsw/7273']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Laser micro sintering,Laser Micro Sintering – A Quality Leap through Improvement of Powder Packing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6568fd0d-6353-48e0-bea6-6dcf66d490ef/download,,"Laser micro sintering, a modification of selective laser sintering for freeform fabrication
of micro-parts, was continuously upgraded since its first application. Poor density of the powder
layers has been a persisting problem that had to be dealt with from the beginning. One solution
was the application of high intensity q-switched laser pulses. Compaction of the material and
improvement of the sinter resolution was achieved. But with these pulse-regimes only limited
density of the sintered body has been achievable. Recently special efforts have been made to get
rid of or at least reduce these drawbacks by markedly higher compaction of the respective powder
layers. There is clear evidence that with sufficiently compacted powder layers even laser micro
sintering with continuous radiation should be feasible. Till recently laser sintering of metal had
been applied mainly to produce monolithic components. With the upgraded technique direct
generation of micro devices with freely movable subassemblies can be possible.",,,,,,
"['Yeung, H.', 'Neira, J.', 'Lane, B.', 'Fox, J.', 'Lopez, F.']",2021-10-26T18:04:44Z,2021-10-26T18:04:44Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89543,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'additive manufacturing', 'laser scan path', 'powder control', 'G-code']",Laser Path Planning and Power Control Strategies for Powder Bed Fusion Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dbe01770-8482-40a5-ad07-29ea493b1bb2/download,University of Texas at Austin,"In laser powder bed fusion additive manufacturing (AM) process, laser scan path, velocity,
and power are some of the most important parameters affecting the build quality. Control strategies
for laser path and power are implemented and tested on a prototype testbed based on industrial
standard G-code type programming language (referred to as AM G-code). The proposed AM G-code demonstrates different modes which define power-velocity-position profiles, and account for
the laser and scanner dynamics. AM G-code is interpreted into xy2-100 protocol and sent to the
galvo scanners and laser using a custom transmitter. The actual scan path is compared with the
commanded path during controlled tests. The proposed AM G-code interpreter modes are then
evaluated considering the measured dynamic system response, and further discussed in contrast to
commercial powder bed fusion systems.",,,,,,
"['Laoui, Tahar', 'Wang, Xiaochuan', 'Childs, T.H.C.', 'Kruth, Jean-Pierre', 'Froyen, Ludo']",2019-09-23T17:01:22Z,2019-09-23T17:01:22Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75972', 'http://dx.doi.org/10.26153/tsw/3071']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Penetration,Laser Penetration in a Powder Bed During Selective Laser Sintering of Metal Powders: Simulations Versus Experiments 453,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e75e8ef2-11b7-4b40-927c-687dd312efe7/download,,"To gain a better understanding and control of the Selective Laser Sintering (SLS) process, more fundamental and modeling work is needed. A simple analytical ray-tracing model has been developed to simulate the energy absorption and penetration in SLS. The model is applied to FeCu and WC-Co powder mixtures, irradiated by Nd-YAG or CO2 laser. It gives an evaluation of the total energy incoupling and optical penetration of the laser beam in a powder bed and an estimation of the sintering zone dimensions. Another model, which considers heat flow by conduction in the bed, has also been used to estimate the sintering dimensions of one laser track.",This research is supported by the national fund IUAP/PAI P4/33.,,,,,
"['Wang, Hongyun', 'Bourell, David', 'Beaman, Joseph J.']",2019-02-18T17:47:36Z,2019-02-18T17:47:36Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73394', 'http://dx.doi.org/10.26153/tsw/546']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'CO2']",Laser Polishing of Silica Rods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/319c6356-09fb-47aa-9619-ba1bd45d7247/download,,"Lasers have been widely used in surface modification. In this research a CO2 continuous
wave laser has been used to polish the slot surface of the silica rods. The strong absorption of the
lO.6 um C02 radiation by the silica surface promotes the softening of a very thin layer of material
that flows under the action of surface tension. As a result, a mirror smooth glassy surface has been
formed which decreases the surface roughness without any substantial change in the surface
geometries. The effect of laser to surface inclination angle on the requisite power requirement was
assessed experimentally and theoretically. With laser beam scanning controlled by a computer aided design (CAD) database without specific tooling or human intervention, reliability and
reproducibility of this process have been greatly improved compared to conventional fire polishing.
The potential use of laser polishing as a post-processing step for freeform-fabricated parts is very
promising.",,,,,,
"['Uddin, Syed Zia', 'Espalin, David', 'Mireles, Jorge', 'Morton, Philip', 'Terrazas, Cesar', 'Collins, Shane', 'Murr, Lawrence E.', 'Wicker, Ryan']",2021-11-02T14:44:34Z,2021-11-02T14:44:34Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89814,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['aluminum alloy 6061', 'laser melting powder bed fusion', 'crack-free', 'induction heating', 'high density']",Laser Powder Bed Fusion Fabricated and Characterization of Crack-Free Aluminum Alloy 6061 Using In-Process Powder Bed Induction Heating,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6d92b0c2-b404-4f72-b783-0c07a684a213/download,University of Texas at Austin,"A parameter development study for pre-alloyed aluminum alloy 6061 (AA6061) was
carried out using an open-architecture powder bed laser melting (LM) technology with capabilities
of induction heating for raising the powder bed temperature. Cube specimens (10 mm on each
side) were used for parameter development with variation in laser power and scanning speed,
whereas layer thickness, hatch spacing and powder bed temperature were empirically determined.
While higher relative densities were achieved when using induction heating (as compared to
specimens fabricated without induction heating), the key difference in the experiments was the
ability to fabricate specimens without cracks when using induction heating. That is, crack-free
AA6061 parts were fabricated with the highest relative density measured of 98.7%. Micrographs
of specimens fabricated with the induction heating demonstrated the lack of melt pool and melt
track features, which are normally only achieved with post-processing heat treatments. This
research was important in its approach of using high temperature heating of the powder bed prior
to laser scanning to produce crack-free AA6061 parts. Further investigations are ongoing to
explore and optimize this fabrication process.",,,,,,
"['Oztan, Cagri', 'Fodran, Eric', 'Barnes, Eric', 'LeBlanc, Saniya']",2023-01-20T14:18:31Z,2023-01-20T14:18:31Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117257', 'http://dx.doi.org/10.26153/tsw/44138']",eng,2022 International Solid Freeform Fabrication Symposium,Open,laser powder bed fusion,Laser Powder Bed Fusion of Bismuth Telluride: Process-Structure-Property Relationships,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d4323d95-23eb-4fb4-825a-5d3f178fb97d/download,,"Thermoelectric generators possess a vast potential for waste heat recovery. Yet, the traditional 
fabrication methods of thermoelectric structures suffer from material loss and are limited to 
planar geometries. As a solution, laser additive manufacturing of thermoelectric materials has 
attracted considerable attention. In this research, the process-structure-property relationship of 
laser processed bulk bismuth telluride parts has been explored. Under constant laser power and 
scan speed, the effects of variation in scan pattern, number of scans, hatch spacing and layer 
height on the microstructural and thermoelectric properties were investigated. It was concluded 
that the laser powder bed fusion enables formation of intensive interfaces with preferential grain 
growth and certain scan patterns result in enhancement in relative density and thermoelectric 
properties.",,,,,,
"['Lantzsch, T.', 'Westphalen, T.', 'Tenbrock, C.', 'Traub, M.', 'Haefner, C.L.']",2021-12-07T18:38:26Z,2021-12-07T18:38:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90752', 'http://dx.doi.org/10.26153/tsw/17671']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['dual fiber laser array', 'fiexible optical system', '316L', 'stainless steel', 'laser powder bed fusion']",Laser Powder Bed Fusion of Stainless Steel 316L Using a Flexible Dual Fiber Laser Array,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a8a964f0-c7fc-473b-9e0d-c1d361a4ce01/download,University of Texas at Austin,"In recent years, Laser Powder Bed Fusion (LPBF) has become an industrially established
manufacturing technique. State-of-the-art LPBF machines feature a combination of fiber lasers and
galvanometer scanners due to their high dynamic and excellent focusability. To increase the productivity of
LPBF machines the number of laser scanner systems (LSS) is multiplied, which causes an almost linear
increase of machine costs. In this study a flexible optical system which allows the combination of two fiber
lasers with a single galvanometer scanner is developed and integrated into a LPBF lab machine to scale the
productivity within one scan field. The resulting machine is characterized and used for the manufacturing of
test specimen out of stainless steel AISI 316L. The manufactured specimens are analyzed in terms of melt
pool formation via high-speed videography as well as resulting part density and build-up rate. The obtained
results are compared with state-of-the-art LPBF-machines.",,,,,,
"['Yasa, Evren', 'Ozsoy, Andac', 'Tureyen, Erkan Bugra']",2021-12-06T22:04:35Z,2021-12-06T22:04:35Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90690', 'http://dx.doi.org/10.26153/tsw/17609']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['pulsed mode', 'laser powder bed fusion', 'point distance', 'exposure time', '17-4 PH stainless steel']",The Laser Powder Bed Fusion Process Development of 17-4 PH Stainless Steels with Pulsed-Wave Lasers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf19e436-a60e-4894-a5fa-fc4e16c24e59/download,University of Texas at Austin,"The main advantage of using Laser Powder Bed Fusion is its unique capability to produce
highly complex geometries with intricate features. Besides other differences in powder coating
and gas circulation among various LPBF machines, the type of laser (continuous or pulsed
wave) is the most critical one. In addition to several process parameters to be optimized for a
specific material, pulsed-wave lasers bring extra factors to consider. In this work, a pulsed-wave laser was used to develop process parameters for 17-4 PH stainless steel while keeping
volumetric energy density, laser power and velocity constant to understand the effect of pulse
related parameters on the outputs. As the point distance (PD) between consecutive laser spots
was increased, the exposure time was also raised to keep the scan speed constant. This enabled
achieving PDs with one extreme end approaching CW-lasers while the other end aiming at
keyhole effect.",,,,,,
"['Wimpenny, D.I.', 'Banerjee, S.', 'Jones, J.']",2021-09-29T14:43:52Z,2021-09-29T14:43:52Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88185', 'http://dx.doi.org/10.26153/tsw/15126']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['polymeric toner powder deposition', 'flow control agents', 'charge control agents', 'laser printing']",Laser Printed Elastomeric Parts and Their Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/45bbedd2-a6bb-469b-87c1-95927efec44e/download,University of Texas at Austin,"The precise deposition of polymeric toner powder by laser printing is reliant on having powder
particles with appropriate flow and uniform charge properties. Nanometer sized particles known
as flow control agents (FCA) and charge control agents (CCA) are used to modify powder
behaviour to provide the appropriate characteristic for printing. This paper shows how varying
the quantity of FCA applied to the surface of Somos201 particles can affect the elongation to
failure and ultimate tensile strength of laser printed tensile test specimens.",,,,,,
"['Banerjee, Soumya', 'Wimpenny, David Ian']",2020-03-02T14:31:35Z,2020-03-02T14:31:35Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80125', 'http://dx.doi.org/10.26153/tsw/7146']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Electrophotography,Laser Printing of Polymeric Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/faccf79c-b314-4d14-a151-a767aca9751d/download,,"Electrophotography, the basis of photocopying and laser printing, is a reliable and well developed
method of precisely depositing fine powders to form text or images. The process is highly
adaptable to different types of materials; commercial toners are based on particular polymers but
researchers have already shown the potential to deposit other materials including metals and
ceramics. Once the powder layer has been deposited it can be heated to form a fused layer.
This paper describes research conducted at DeMontfort University to develop a range of toners
based on conventional engineering polymers and concludes by outlinning the challenges which
will be tackled in the next phase of research.",,,,,,
"['Kletetzka, I.', 'Kummert, C.', 'Schmid, H.-J.']",2021-12-01T21:58:29Z,2021-12-01T21:58:29Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90629', 'http://dx.doi.org/10.26153/tsw/17548']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'media transmission', 'design guidelines']",Laser Sintering Design Guidelines for Media Transmitting Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2148c86f-13d3-4945-aed3-32bfd606c0ac/download,University of Texas at Austin,"In automotive and other fields of application media transmitting components are made of
plastics for reasons of weight and cost and complex, flow-optimized geometries are most desirable.
Therefore, the laser sintering technology (SLS) is predestinated to manufacture these components
as it offers a very high degree of design freedom and good mechanical properties. For industrial
applications the long-term properties of the SLS material in contact with liquid media are important
and were therefore investigated for polypropylene (PP) and polyamide (PA613). The mechanical
properties were tested after immersion and compared to injection molded samples. Furthermore,
laser sintering design guidelines for media transmitting components were developed. These
guidelines for instance include the minimum wall thickness to ensure media tightness and strategies
for the removal of powder from channels with a high length to diameter ratio.",,,,,,
"['Niino, Toshiki', 'Oizumi, Shunsuke', 'Otsuki, Hiroyuki']",2020-03-10T15:32:47Z,2020-03-10T15:32:47Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80217', 'http://dx.doi.org/10.26153/tsw/7236']",eng,2007 International Solid Freeform Fabrication Symposium,Open,laser sintering,Laser Sintering Fabrication of Highly Porous Models Utilizing Water Leachable Filler-Experimental Investigation into Process Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9a8f817-1a52-4b93-8420-1586fb0030b1/download,,"The authors are developing a laser sintering process to fabricate highly porous
models with such high porosities as 90% and more. In the process, water-soluble filler is
mixed with designated plastic powder and leached out after laser sintering process is
finished to generate pores where the grains used to exist. Previously, the authors
reported successful application of this technology on a tissue engineering scaffold.
However, relationship between process parameters and obtained results has not been
clarified. This paper reports experimental investigation into effects of optimizing
process parameters such as mixture, grain size of the filler on resultant porosity, pore
size and process resolution",,,,,,
"['Nelson, J.C.', 'Vail, N.K.', 'Barlow, J.W.']",2018-05-03T20:03:03Z,2018-05-03T20:03:03Z,1993,Mechanical Engineering,doi:10.15781/T2G737N0C,http://hdl.handle.net/2152/65080,,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'computer model', 'sintering model']",Laser Sintering Model for Composite Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/baf23ea0-2511-468b-8742-fa46c371433c/download,,"A computer model for the sintering of ceramic/polymer composite
materials has been established based on empirical sintering rate data. The
model calculates sintering depths which result from variations in the
operating parameters which include laser power, beam speed, scan
spacing, scan vector length, and initial temperatures of the powder and
surroundings. Sintering depths measured in multiple layer parts made of
polymer coated ceramic powders are compared to sintering depths
calculated by the sintering model.",,,,,,
"['Strobbe, D.', 'Van Puyvelde, P.', 'Kruth, J.-P.', 'Van Hooreweder, B.']",2021-11-11T16:04:13Z,2021-11-11T16:04:13Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90228', 'http://dx.doi.org/10.26153/tsw/17149']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'polyamides']","Laser Sintering of PA12/PA4,6 Polymer Composites",Conference paper,https://repositories.lib.utexas.edu//bitstreams/9b965a5a-1a40-4504-8a18-a2b59dbc98c8/download,University of Texas at Austin,"This work investigates the laser sintering (LS) processing of polyamide-12/polyamide-4,6
composites and the performance of resulting parts. The coalescence and consolidation of the
PA12/PA4,6 powder mixture are characterized. This demonstrates that at the LS processing
window for PA12 (grade PA2200), the powder mixture exhibits bimodal melting behavior. In this
behavior PA2200 melts during LS processing but PA4,6 remains solid. After laser sintering of the
materials, the microstructure and the mechanical properties of the resulting parts are characterized.
This illustrates that the PA2200 coalesces well and PA4,6 remains as a secondary phase during the
LS processing. Further developments to improve the powder size and morphology in order to
obtain better relative density of the parts are necessary. The investigated processing approach
opens up new perspectives for LS of advanced engineering thermoplastics.",,,,,,
"['Zhang, Hui', 'Bourell, David L.', 'Guo, Yanling', 'Li, Jian', 'Zhang, Xiaodong', 'Zhuang, Yu', 'Li, Zhipeng']",2021-11-18T02:22:27Z,2021-11-18T02:22:27Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90413', 'http://dx.doi.org/10.26153/tsw/17334']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'biomass composites', 'pine-polylactic acid', 'mechanical properties', 'microstructures', 'dimensional accuracy']",Laser Sintering of Pine/Polylatic Acid Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3201703b-9cd6-45e2-ae6e-144c9f282dc1/download,University of Texas at Austin,"A new powder feedstock composed of sustainable and degradable biomass composite
material was proposed for laser sintering technology in this research. This biomass mixture,
abbreviated P-PLA, is made up of mechanically mixed polylactic acid (PLA) powder and pine
powder. The proper processing parameters were determined based on the component thermal
behavior and laser sintering testing: processing temperature 130-135°C, laser power 20-24 W, scan
spacing 0.1-0.2 mm, scan speed 1.6-2.2 m/s and layer thickness 0.2mm. Laser-sintered P-PLA parts
exhibited much better mechanical properties compared with pine/polyethersulfone copolyester (PCoPES) wood-plastic composite, with tensile strength 34-200% higher and flexural strength 92-
246% higher than values for laser-sintered P-CoPES. Results reveal that pine powder loading can
reduce the shrinkage and deformation of laser-sintered P-PLA parts. Shrinkage decreased from 4%
to 0.31-2.27% in the XY plane and from 3.25% to 0.13-2.25% in the Z direction.",,,,,,
"['Imai, Y.', 'Kyogoku, H.', 'Shiraishi, K.']",2020-02-21T15:24:52Z,2020-02-21T15:24:52Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80062', 'http://dx.doi.org/10.26153/tsw/7084']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Selective laser sintering,Laser Sintering of Stainless Steel using Resin Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbf8dde6-2455-4939-921b-04803c655ea3/download,,"We tried laser sintering of 316L stainless steel powder using resin powder. The laser
sintering conditions such as laser power, scan speed and scan pitch with a YAG laser, and the
influence of additional resin powder on the density and the tensile properties of the sintered alloy
were investigated experimentally. The tensile specimen was laser-sintered with a YAG laser, and
then debound and sintered in a vacuum furnace. The tensile specimen was successfully fabricated.
The relative density and the tensile strength varied with the additional resin powder, and the
optimum weight percentage of additional resin powder was around 4%.The relative density of the
sintered alloy was approximately 85%, and the tensile strength and elongation of the sintered
alloy were more than 280 MPa and 15% respectively.",,,,,,
"['Wu, Ying-Jeng Engin', 'Beaman, Joseph J.']",2018-04-19T18:10:56Z,2018-04-19T18:10:56Z,1992,Mechanical Engineering,doi:10.15781/T2D21S21R,http://hdl.handle.net/2152/64398,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'SFF application', 'three-dimensional']",Laser Tracking Control Implementation for SFF Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a27e6c9-44c2-48b7-82db-070bed6eac7d/download,,"From a three-dimensional computer graphic model, Solid Freeform Fabrication
produces solid objects directly without special tooling and human handling. In order to
increas process productivity and accuracy, a time-efficient laser tracking control technique
is needed. Based on the minimum time optimal control solution, the desired laser scanning
control system is designed and implemented. To obtain uniform solidification during timeefficient
tracking which has variable speed, laser power intensity is also controlled in real
time by an acousto-optic modulator.",,,,,,
"['Lu, Y.', 'Shao, D. B.', 'Chen, S. C.']",2020-02-13T20:28:04Z,2020-02-13T20:28:04Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79974', 'http://dx.doi.org/10.26153/tsw/6999']",eng,2004 International Solid Freeform Fabrication Symposium,Open,laser-assisted photothermal,Laser-assisted photothermal imprinting of nanocomposite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9041c9a-7fbc-4e83-b41f-ada0e6795a71/download,,"We report on a laser-assisted photothermal imprinting method for directly patterning carbon
nanofiber-reinforced polyethylene nanocomposite. A single laser pulse from a solid state
Nd:YAG laser (10 ns pulse, 532 nm and 355 nm wavelengths) is used to melt/soften a thin skin
layer of the polymer nanocomposite. Meanwhile, a fused quartz mold with micro-sized surface
relief structures is pressed against the surface of the composite. Successful pattern transfer is
realized upon releasing the quartz mold. Although polyethylene is transparent to the laser beam,
the carbon nanofibers in the high density polyethylene (HDPE) matrix absorb the laser energy
and convert it into heat. Numerical heat conduction simulation shows the HDPE matrix is
partially melted or softened, allowing for easier imprinting of the relief pattern of the quartz
mold.",,,,,,
"['Ahmadi, Zabihollah', 'Lee, Seungjong', 'Shamsaei, Nima', 'Mahjouri-Samani, Masoud']",2021-11-18T00:55:47Z,2021-11-18T00:55:47Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90380', 'http://dx.doi.org/10.26153/tsw/17301']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser surface processing', 'surface defects', 'surface roughness', 'pores', 'fatigue behavior', 'titanium', 'additive manufacturing']",Laser-Assisted Surface Defects and Pore Reduction of Additive Manufactured Titanium Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1ae62e2-edac-4e62-9d2d-38ddd553381c/download,University of Texas at Austin,"Laser surface treatment of additively manufactured parts has attracted considerable interest in the
past few years due to its flexibility, operation speed, and capability for polishing complex surfaces
as compared to conventional mechanical based methods. This study presents the role of laser
surface processing in minimizing the surface roughness and pores that have detrimental effects on
the fatigue behavior of additively manufactured specimens. This study is performed by a precise
laser melting and recrystallization process to close the pores within 70 μm of the surface in order
to enhance the fatigue life of these specimens. A continuous-wave fiber laser is employed to
investigate the effect of various processing parameters for controlled laser surface treatments in
this study.",,,,,,
"['Li, Xiaochun', 'Choi, Hongseok', 'Yang, Yong']",2019-10-24T18:31:49Z,2019-10-24T18:31:49Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77422', 'http://dx.doi.org/10.26153/tsw/4511']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Laser-Based Meso/Micro Rapid Manufacturing System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5cd4264a-7483-49bf-932b-57e0a5adad39/download,,"The meso/micro layered manufacturing technologies have significant implications for the
design and fabrication of complex miniature structures. A laser-based additive/subtractive Rapid
Manufacturing system is thus developed to build meso/micro structures. By incorporating laser
microdeposition and micromachining with a pulsed Nd:YAG laser that has four harmonic
wavelengths, this manufacturing system takes computer-aided design (CAD) output to reproduce
meso/micro components in a wide selection of materials. To precisely deposit micro/nano
powders and to control composition in-situ, an ultrasonic-based micro powder-feeding
mechanism is developed. This additive/subtractive micro/meso manufacturing technology
provides a platform for a solid integration from CAD to the realization of complex 3D miniature
parts.","The authors are grateful to the support from Wisconsin Alumni Research Foundation and
National Science Foundation.",,,,,
"Zhou, Wenchao",2021-10-21T18:12:38Z,2021-10-21T18:12:38Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89415,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Lattice Boltzmann Method', 'multiple droplet interaction', 'inkjet deposition', 'contact angle', 'non-ideal surfaces']",Lattice Boltzmann Simulation of Multiple Droplet Interaction on Non-ideal Surfaces for Inkjet Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e151d9f7-3f91-418b-b23e-1af85d9029a5/download,University of Texas at Austin,"Inkjet deposition enables a more efficient, economic, scalable manufacturing process for a wider
variety of materials than other traditional additive techniques. The interaction dynamics of
inkjettted droplets on surfaces are crucial for controlling the formation of the printed patterns, the
accuracy of which is critical to the functionalities of the printed device (e.g., electronics).
However, little research has been reported on this front due to the prohibitive computational cost
of simulating the dynamics of multiple droplet interaction on surfaces. Recently, Zhou et al. [1]
reported an efficient numerical solver based on Lattice Boltzmann Method (LBM) that enabled
the simulation of multiple droplet interaction dynamics on an ideal surface (i.e., smooth and
homogeneous). In this model, the final shape of the droplets always relax back to the equilibrium
shape (i.e., spherical cap) prescribed by the static contact angle of the idea surface, which does
not provide any useful information on the final printed pattern. In order to simulate the printed
pattern in real world, it is necessary to take into consideration of the contact angle hysteresis
phenomenon on a non-ideal surface, which is caused by the surface roughness and chemical
inhomogeneity of the surface. In this paper, a dynamic contact angle boundary condition is
developed to take into account the contact angle hysteresis effect based on the previously
reported LBM model. The improved LBM model was validated with experimental data from
literature. The influence of the printing conditions, droplet spacing, and surface conditions on the
two-droplet interaction dynamics were investigated with the validated LBM model. Interesting
phenomena were observed and discussed. The interaction of a line of six droplets on a non-ideal
surface was simulated to demonstrate the powerful capability of the developed numerical solver
in simulating real-world inkjet printing process.",,,,,,
"['Zhou, Wenchao', 'Loney, Drew', 'Fedorov, Andrei G.', 'Levent Degertekin, F.', 'Rosen, David W.']",2021-10-11T21:35:28Z,2021-10-11T21:35:28Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88651', 'http://dx.doi.org/10.26153/tsw/15585']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['droplet interactions', 'inkjet deposition', 'Lattice Boltzmann Method', 'COMSOL', 'droplet impingement', 'inkjet manufacturing']",Lattice Boltzmann Simulations of Multiple Droplet Interactions During Impingement on the Substrate,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f2ce02da-0804-4984-8e52-6db732e9880a/download,University of Texas at Austin,"Studying material interface evolution in the course of multiple droplet interactions is critical
for understanding the material additive process in inkjet deposition. In this paper, we have
developed a novel numerical model based on the Lattice Boltzmann Method (LBM) to simulate
the interface dynamics during impingement and interaction of multiple droplets. A lattice
Boltzmann formulation is proposed to solve the governing equations of the continuous phasefield model that are used in commercial software COMSOL. The LBM inter-particle force is
derived by comparing the recovered macroscopic equations from LBM equations with the
governing equations of the phase-field model. In addition, a new set of boundary conditions for
the LBM formulation is proposed based on conservation of mass and momentum to ensure
correct evolution of contact line dynamics. The results of LBM simulations are compared with
those of COMSOL and experimental data from literature. The comparison shows the proposed
LBM model not only yields a significant improvement in computational speed, but also results in
better accuracy than COMSOL as validated against the experiments. We have also demonstrated
the capability of the developed LBM numerical solver for simulating interactions between
multiple droplets impinging on the substrate, which is critical for development and optimization
of inkjet manufacturing.",,,,,,
"Bhate, Dhruv",2021-11-08T23:30:52Z,2021-11-08T23:30:52Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90076', 'http://dx.doi.org/10.26153/tsw/16997']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['lattice design', 'design optimization', 'crowdsourcing', 'classroom', 'students', 'design for additive manufacturing']",Lattice Design Optimization: Crowdsourcing Ideas in the Classroom,Conference paper,https://repositories.lib.utexas.edu//bitstreams/998cd9fb-a351-40b1-92ba-c28e0b2a0475/download,University of Texas at Austin,"Crowdsourcing is a powerful method of generating ideas, particularly when there are many
possible solutions to a particular problem with no obvious process towards arriving at the optimum
one. In this paper, results of a crowdsourcing exercise conducted in a 30-student classroom are
reported. Students were tasked with using lattice design concepts to minimize the weight of a beam
under bending, tension and torsion. Using the nTopology software, they approached the problem
in three steps: (1) Selection/design of a unit cell, (2) Distribution of cell size, and (3) Optimization
of the thickness of individual members. The first two steps were design decisions made by the
students, the last step used nTopology's native solver. This work shares insights gained both in
lattice design itself, as well as on the use of crowdsourcing in the classroom, particularly in the
context of the rapidly evolving field of Design for Additive Manufacturing.",,,,,,
"['Tang, Y.', 'Zhao, Y.F.']",2021-10-21T19:11:16Z,2021-10-21T19:11:16Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89425,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['lattice-skin structures', 'lattice orientation', 'orientation optimization', 'additive manufacturing']",Lattice-skin Structures Design with Orientation Optimization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eebcca65-ec7e-4314-961e-80c2352d5909/download,University of Texas at Austin,"Parts with complex geometry can be produced by an additive manufacturing process
without a significant increase of fabrication time and cost. One application of AM technologies
is to fabricate customized lattice structures to enhance products’ performance with less material
and less weight. Thus, design methods of customized lattice structures have recently attracted
great research interests. Most existing design methods only consider the distribution of lattice
struts’ thickness as a primary design variable for customized lattice structures. Few of them
notice the importance of lattice orientation with regard to its structural performance. In this
paper, a design method for customized lattice-skin structures is proposed to optimize the
distribution of lattice orientations inside the design domain. In this design method, an initial
Functional Volume (FV) is divided into several sub-FVs and connected with additional
Functional Surfaces (FSs). The orientation of uniform lattice in each sub-FV is regarded as the
design variable. To optimize the design variables, an equivalent analysis model based on the
effective orthotropic properties of lattice structures is built. On the basis of this model, genetic
algorithm is applied to obtain the optimized distribution of lattice orientations. Two case studies
are provided at the end of this paper to validate the proposed design method.",,,,,,
"['Conner, Timothy Glen', 'Loerwald, Matthew', 'Hayasi, Mohammad', 'Asiabanpour, Bahram']",2021-10-04T20:47:18Z,2021-10-04T20:47:18Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88344', 'http://dx.doi.org/10.26153/tsw/15283']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Fully Dense Freeform Fabrication', 'FDFF', 'layer alignment', 'layer bonding']",Layer Alignment and Lamination for the Fully Dense Freeform Fabrication (FDFF) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/09693bd8-4681-4aa8-93ad-d240026ac8e8/download,University of Texas at Austin,"Fully Dense Freeform Fabrication uses an adaptive layering method for predefined sheets
and uses slices cut by a water cutter or laser cutter machine for manufacturing functional parts
through smart layer alignment, adjustable compression system, and compatible bonding
materials. Under pressure and heat, layers are attached and form a 3D prototype. This paper
presents an automated alignment mechanism and compression bonding method that is functional
for a variety of complex parts. The alignment system makes a nest setting by using five linear
actuators and the compression system is using an array of uneven pins that are locked by sliding
surfaces.",,,,,,
"['Zeng, Kai', 'Patil, Nachiket', 'Gu, Hengfeng', 'Gong, Haijun', 'Pal, Deepankar']",2021-10-07T15:28:32Z,2021-10-07T15:28:32Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88481', 'http://dx.doi.org/10.26153/tsw/15415']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['geometrical accuracy', 'Additive Manufacturing', 'Common Layer Interface', 'StereoLithography Interface', 'layer-bylayer', 'part quality']",Layer by Layer Validation of Geometrical Accuracy in Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a3014d69-f562-4386-9a03-8c722eb4aa63/download,University of Texas at Austin,"Geometrical inaccuracy from shrinkage and residual stress-induced deformations are key sources of
defects in Additive Manufacturing (AM). In most AM processes the CAD model is represented by an STL
file which is sliced into layers. The Common Layer Interface (CLI) and StereoLithography Interface (SLI)
files are two layer file formats which store this slice information and can be data mined to analyze
sources of error. By comparing the original STL file against a ‘stacked’ model based upon SLI and CLI files,
a “theoretical"" part accuracy can be created. In addition, these SLI/CLI files can be combined with
detailed process parameter knowledge such as scan pattern, laser power, scan speed, etc., to enable a
numerical prediction of part accuracy and deformations on a layer-by-layer basis. This paper introduces
a research project which is developing software and hardware tools to enable prediction and
measurement of part dimensions on a layer-by-layer basis with the goal of real-time part quality
validation and closed loop control.",,,,,,
"['Badrossamay, M.', 'Childs, T. H. C.']",2020-02-28T16:25:31Z,2020-02-28T16:25:31Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80115', 'http://dx.doi.org/10.26153/tsw/7136']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,Layer Formation Studies in Selective Laser Melting of Steel Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b1d5e9e-2ec0-46e3-a000-984e609828d9/download,,"This paper advances the findings of the selective laser melting (SLM) of tool steel and
stainless steel powders. The distinguishing feature is the melting of single layers in deep powder
beds by a continuous CO2 laser. First, effect of process parameters on the surface roughness for
each material is investigated. Based on these results combined with visual observation of the
solidified tracks, the question is then discussed as how the processability of various type of steels
is changed. The results show that surface morphology of layers is affected strongly by scan
spacing, thereby giving a lower average roughness at reduced scan spacing. The effect of scan
speed is also remarkable. In addition, other roughness parameters such as the peak height and
skewness are found to be useful tools for evaluation of laser melted surfaces.",,,,,,
"['Kahnert, M.', 'Lutzmann, S.', 'Zaeh, M.F.']",2020-03-09T13:41:26Z,2020-03-09T13:41:26Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80177', 'http://dx.doi.org/10.26153/tsw/7196']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Electron Beam Sintering,Layer Formations in Electron Beam Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fce7815f-3b52-4f95-afde-cecd93ef6cc8/download,,"Among direct metal processing manufacturing technologies (Rapid Manufacturing), Electron
Beam Sintering (EBS) exhibits a high application potential. Especially, the fast beam deflection
provided by electromagnetic lenses allows the realization of considerable building speeds and
minor residual stresses. Therefore, this paper aims to examine and utilize the given potential for
additive layer manufacturing. In this context, the deployed scanning strategy is a very important
aspect. By means of an increasing computer power, innovative and flexible patterns for the
solidification of the powder can be implemented. Thus, different patterns are being examined and
evaluated. Finally, occurring effects in the exposed zone are introduced.",,,,,,
"['Bocking, Chris', 'Jacobson, David', 'Bennett, Graham']",2019-09-23T16:22:24Z,2019-09-23T16:22:24Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75955', 'http://dx.doi.org/10.26153/tsw/3054']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Photochemical,Layer Manufacturing of Heat Exchange Elements using Photochemical Machining with Diffusion Brazing 325,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4d716d78-6c2d-4768-b713-6c9030b7a1f2/download,,"A number of heat exchanger elements for a Stirling engine were designed but found to be very difficult to manufacture using conventional technology. Each element required 1800 <1mm oval holes through a 70 mm length of the cooler. The elements were produced by repeated photochemical machining of 185 copper sheets of 0.455 mm thickness and joining them using a process known as diffusion brazing. This paper describes the science and process of manufacturing these components. The procedure was complicated by the need to integrate spigots at each end of the cooler, which meant that some layers required selective diffusion soldering.",,,,,,
"['Tang, Lie', 'Ruan, Jianzhoung', 'Sparks, Todd E.', 'Landers, Robert G.', 'Liou, Frank']",2021-09-23T22:12:44Z,2021-09-23T22:12:44Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88036', 'http://dx.doi.org/10.26153/tsw/14977']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Laser Metal Deposition', 'Particle Swarm Optimization', 'layer-to-layer height control', 'mechanical engineering']",Layer-to-Layer Height Control for Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d2bc1c1d-7e34-48f0-95ed-3b136d4e3c08/download,,"A Laser Metal Deposition (LMD) height controller design methodology is presented in
this paper. The height controller utilizes the Particle Swarm Optimization (PSO)
algorithm to estimate model parameters between layers using measured temperature and
track height profiles. The process model parameters for the next layer are then predicted
using Exponentially Weighted Moving Average (EWMA). Using the predicted model,
the powder flow rate reference profile, which will produce the desired layer height
reference, is then generated using Iterative Learning Control (ILC). The model parameter
estimation capability is tested using a four-layer deposition. The results demonstrate the
simulation based upon estimated process parameters matches the experimental results
quite well. Simulation study also shows that the methodology described above works
well in producing the reference layer height.",,,,,,
"['Ikeshoji, T.-T.', 'Yonehara, M.', 'Aoyagi, K.', 'Yamanaka, K.', 'Chiba, A.', 'Kyogoku, H.', 'Hashitani, M.']",2024-03-26T21:23:23Z,2024-03-26T21:23:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124415', 'https://doi.org/10.26153/tsw/51023']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PBF-LB', 'lack-of-fusion', 'Inconel 718', 'machine learning', 'additive manufacturing']",LAYER-WISE IN-PROCESS MONITORING-AND-FEEDBACK SYSTEM BASED ON SURFACE CHARACTERISTICS EVALUATED BY MACHINE-LEARNING-GENERATED CRITERIA,Conference paper,https://repositories.lib.utexas.edu//bitstreams/70b66940-86bd-4147-a73b-2b453d23feb9/download,University of Texas at Austin,"In the laser powder bed fusion (PBF-LB) process, a set of parameters that are considered optimal are
selected. Still, a set of parameters cannot accommodate complex model geometries, model placement in the
build chamber, and unforeseen circumstances, leading to internal defects. Therefore, a new in-situ monitoring
and feedback system has been developed to suppress the occurrence of lack-of-fusion (LOF) defects in the PBF-LB process. This system measures surface properties after each laser irradiation to predict whether LOF defects
occur. Then, if necessary, a feedback process is performed to re-melt the same surface. Evaluation thresholds
are defined by a combination of aerial surface texture parameters created in advance by machine learning of
surface properties and defect occurrence. For example, a square pillar of Inconel 718 alloy built with feedback
had a higher relative density than one without feedback.",,,,,,
"['Seifi, Seyyed Hadi', 'Tian, Wenmeng', 'Doude, Haley', 'Tschopp, Mark A.', 'Bian, Linkan']",2021-11-09T15:24:48Z,2021-11-09T15:24:48Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90093', 'http://dx.doi.org/10.26153/tsw/17014']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['layer-wise process', 'profile monitoring', 'thermal-microstructure', 'laser-based additive manufacturing']",Layer-Wise Profile Monitoring of Laser-Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3c6f8129-b15b-42a3-a30d-91690a47eb7d/download,University of Texas at Austin,"Additive manufacturing (AM) is a novel fabrication technique capable of producing highly
complex parts. Nevertheless, a major challenge is improving the quality of fabricated parts. While
there are a number of ways of approaching this problem, developing data-driven methods that use
AM process signatures to identify these part anomalies can be rapidly applied to improve overall
part quality during build. The objective of this study is to build a new layer-wise process signature
model to create the thermal-microstructure relationship. In this study, we derive novel key process
signatures for each layer (from melt pool thermal images), which are reduced using multilinear
principal component analysis (MPCA) and are directly correlated with layer-wise quality of the
part. Using these key process signatures, a Gaussian SVM classifier model is trained to detect the
existence of anomalies inside a layer. The proposed models are validated through a case study of
real-world direct laser deposition experiment where the layer-wise quality of the part is predicted
on the fly. The accuracy of the predictions is calculated using three measures (recall, precision,
and f-score), showing reasonable success of the proposed methodology in predicting layer-wise
quality. The ability to predict layer-wise quality enables process correction to eliminate anomalies
and to ultimately improve the quality of the fabricated part.",,,,,,
"['Starly, B.', 'Nam, J.', 'Lau, W.', 'Sun, W.']",2019-10-22T17:39:05Z,2019-10-22T17:39:05Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76323', 'http://dx.doi.org/10.26153/tsw/3412']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Fabrication,Layered Composite Model for Design and Fabrication of Bone Replacement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf66be92-91d5-4c91-97f6-7682917eda34/download,,"Biological tissues are inherently heterogeneous. The design of 3D tissue scaffolds for tissue
engineering application should, if possible, biomimic the complex hierarchy and structural
heterogeneity of the replaced tissues. This is particularly true for design of bone scaffolds with
structural properties compatible with the spatial heterogeneity and mechanical properties of the
replaced tissue. The paper presents an image-based computer modeling approach for
reconstruction, characterization, and biomimetic modeling and design of three-dimensional
heterogeneous tissue structure. The presented work will cover: 1) overview of biomimetic
modeling and design of bone structures and reverse engineering for CAD-based constructive
solid geometry; 2) design of bone scaffold; and 3) slicing and process planning for solid freeform
fabrication","We gratefully acknowledge support from NSF CRCD-9980298 and support from Therics,
Inc.",,,,,
"['Yasar, O.', 'Martin, M.', 'Harris, C.', 'Sun, S.', 'Starly, B.']",2020-03-10T16:13:44Z,2020-03-10T16:13:44Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80222', 'http://dx.doi.org/10.26153/tsw/7241']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Hydrogel Patterning,Layered Fabrication of Branched Networks Using Lindenmayer Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4184ec42-16e7-45ee-9845-553d14497b2f/download,,"A current challenge impeding the growth of bone tissue engineering is the lack of
functional scaffolds of geometric sizes greater than 10mm due to the inability of cells to
survive deep within the scaffold. It is hypothesized that these scaffolds must have an
inbuilt nutrient distribution network to sustain the uniform growth of cells. In this
paper, we seek to enhance the design and layered fabrication of scaffold internal
architecture through the development of Lindenmayer systems, a graphical language
based theory to create nutrient delivery networks. The scaffolds are fabricated using the
Texas Instruments DLP™ system through UV‐photopolymerization to produce
polyethylene glycol hydrogels with internal branch structures.   The paper will discuss
the Lindenmayer system, process planning algorithms, layered fabrication of samples,
challenges and future tasks.",,,,,,
"['Kietzman, J. W.', 'Cooper, A. G.', 'Weiss, L. E.', 'Schultz, L.', 'Lombardi, J. L.', 'Prinz, F. B.']",2018-11-28T21:27:45Z,2018-11-28T21:27:45Z,1997,Mechanical Engineering,doi:10.15781/T22805J53,http://hdl.handle.net/2152/70333,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SDM', 'Shape Deposition Manufacturing']",Layered Manufacturing Material Issues for SDM of Polymers and Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/14761699-eca2-44b7-8a87-36ecf0b037f1/download,,"Shape Deposition Manufacturing (SDM) is a solid freeform fabrication process which
enables the manufacture of structural parts from engineering materials. This paper discusses the
requirements and constraints for SDM part and sacrificial support materials, including chemical and
physical compatibility, mutual adhesion, low shrinkage, machinability, and support material
removability. Polymers and ceramics processed by SDM include polyurethanes, epoxies,
polyurethane foams, photocurable acrylics, and green alumina ceramics. SDM compatible support
materials include waxes, water-soluble polyacrylate soldermasks, and water-soluble
thermoplastics. This paper details the selection of SDM part and support material combinations for
the fabrication of polymer prototypes and polymer molds for ceramic prototyPes.",,,,,,
"['Messia, David', 'Pegna, Joseph', 'Lee, Woo Ho']",2018-11-29T21:08:44Z,2018-11-29T21:08:44Z,1997,Mechanical Engineering,doi:10.15781/T2G737Q08,http://hdl.handle.net/2152/70346,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['3-D LCVD', 'SALD']",Layered Micro-Wall Structures from the Gas Phase,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f48a57f9-6b72-4022-9b4b-402a90231448/download,,"The use of3-D LCVD with volumetric rate feedback was investigated in the fabrication
ofmicromechanical wall structures. These were constructed by recursive laser scanning and
resulted in layered wall composed ofrecursive line deposition.
Experiments were designed to uncover the relationship between scan rate, volumetric deposition
rate, pressure and laser powerfor pyrolytic graphite from an ethylene precursor. Results point to
a conduction dominated heat transfer which greatly limits the volumetric deposition rate at the
wall. This also results in a highly unstable deposition process, since volumetric deposition
increases by orders ofmagnitude as soon as rod growth is initiated.
An unexpected results ofthis work is the ability to grow rods at an angle to the laser axis, with
good control ofthe linear growth rate. This is achieved by adaptive laser scanning during rod
growth.",,,,,,
"['Zak, G.', 'Sela, M.N.', 'Park, C.B.', 'Benhabib, B.']",2018-11-28T16:43:33Z,2018-11-28T16:43:33Z,1997,Mechanical Engineering,doi:10.15781/T2M61C89K,http://hdl.handle.net/2152/70321,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['UV Laser Based System', 'Composite Liquid', 'liquid leveling subsystems']",A Layered-Manufacturing Process For the Fabrication of Glass-Fiber-Reinforced Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0221f42e-87cc-4f7b-b7fd-51b6a1ee92b1/download,,"In this paper, we present a rapid manufacturing process for the layered fabrication of
polymer-based composite parts using short discontinuous fibers as reinforcements. In the recent
past, numerous research efforts, similar to ours, have been made to produce fiber-reinforced
plastic parts via layered manufacturing methods. However, most of these attempts have not
resulted in the development of an effective commercially-viable manufacturing process. Our
proposed fabrication process on the other hand has been experimentally verified to yield
composite parts comparable in quality to pure polymer parts manufactured on a commercial
stereolithography system.",,,,,,
"['Abdelrahman, Mostafa', 'Starr, Thomas L.']",2021-10-12T21:38:54Z,2021-10-12T21:38:54Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88747', 'http://dx.doi.org/10.26153/tsw/15681']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Polymer Laser Sintering', 'end-use parts', 'high resolution infrared thermal imaging', 'thermal imaging']",Layerwise Monitoring of Polymer Laser Sintering Using Thermal Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7bbf5350-7846-496f-89f3-17f249c230db/download,University of Texas at Austin,"Polymer Laser Sintering (LS) is used increasingly for manufacture of end-use parts.
Improved methods of monitoring the process are needed to certify the quality of these parts. This
paper describes the use of high resolution infrared thermal imaging to monitor the temperature of
individual layers before, during and after laser scanning. The time-temperature history of each
point in a layer depends on process parameters and part geometry. This history also controls the
sintering and crystallization process for a single volume element of the part and its mechanical
properties. Proposed new process control schemes may use this monitoring data to ensure that all
volume elements achieve full density. The proposed framework includes creating a 3D template of
the input model. This template simulates the part fabrication in the SLS machine. Registration of
this template to the monitor data creates a 3D quality certificate for the part.",,,,,,
"['Gill, David D.', 'Griffith, Michelle L.', 'Reckaway, Daryl E.', 'Briner, Clifton F.', 'Abrams, Douglas G.']",2019-11-20T16:49:13Z,2019-11-20T16:49:13Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78482', 'http://dx.doi.org/10.26153/tsw/5567']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Geometries,LENS Deposition of Complex Geometries,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2f2d900e-30bd-4daf-84ca-fde204695386/download,,"The Laser Engineered Net Shaping (LENS®) system at Sandia National Laboratories, a
laser-based direct metal deposition process, was recently used for the fabrication of a complex
prototype. The LENS process involved the challenges of adjacent areas of thick and thin cross
section, overhanging unsupported features, high aspect ratios, and a hemispherical substrate.
These challenges were overcome through the use of closed-loop weld pool control, height
monitoring, a strong understanding of build parameters, and unique process planning strategies.
The near-net shape LENS part was completed with annealing and conventional machining to
produce the complex components in a reduced timeframe.",,,,,,
"['Gill, D. D.', 'Atwood, C. J.', 'Voth, T. E.', 'Robbins, J.', 'Dewhurst, P.', 'Taggart, D. G.']",2020-03-10T14:30:37Z,2020-03-10T14:30:37Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80210', 'http://dx.doi.org/10.26153/tsw/7229']",eng,2007 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,LENS® and SFF: Enabling Technologies for Optimized Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1d9de28-6146-4de2-acd6-2284351e6dba/download,,"Optimized, lightweight, high-strength structures are needed in many applications from aerospace
to automotive. In pursuit of such structures, there have been proposed analytical solutions and
some specialized FEA solutions for specific structures such as automobile frames. However,
generalized 3D optimization methods have been unavailable for use by most designers.
Moreover, in the cases where optimized structural solutions are available, they are often hollow,
curving, thin wall structures that cannot be fabricated by conventional manufacturing methods.
Researchers at Sandia National Laboratories and the University of Rhode Island teamed to solve
these problems. The team has been pursuing two methods of optimizing models for generalized
loading conditions, and also has been investigating the methods needed to fabricate these
structures using Laser Engineered Net Shaping™ (LENS®) and other rapid prototyping
methods. These solid freeform fabrication (SFF) methods offer the unique ability to make
hollow, high aspect ratio features out of many materials. The manufacturing development
required for LENS to make these complex structures has included the addition of rotational axes
to Sandia’s LENS machine bringing the total to 5 controlled axes. The additional axes have
required new efforts in process planning. Several of the unique structures that are only now
possible through the use of SFF technology are shown as part of the discussion of this exciting
new application for SFF.",,,,,,
"['White, Liam', 'Quaife, Bryan', 'Borish, Michael', 'Adkins, Cameron', 'Roschli, Alex']",2024-03-26T17:10:56Z,2024-03-26T17:10:56Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124379', 'https://doi.org/10.26153/tsw/50987']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['hybrid manufacturing', 'additive manufacturing', 'subtractive manufacturing', 'OpenVDB', 'sparse volumetric grid', 'voxel grid', 'level set function', 'signed distance function', 'marching squares']",Level Set Grids for Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/014c22ba-300f-4422-9191-7be9ebbd4264/download,University of Texas at Austin,"We propose a novel hybrid model, the Level Set Grid, to facilitate parallel additive and
subtractive processes in hybrid manufacturing. The Level Set Grid combines the strengths of
explicit and implicit representations, offering precise modeling of evolving geometries and fast
and efficient collision detection. This research focuses on integrating Level Set Grids into the
additive slicing and subtractive pathing generation processes, laying the groundwork for future
advancements in the parallelization of hybrid manufacturing.",,,,,,
"['Chung, Haseung', 'Das, Suman']",2019-11-20T16:27:48Z,2019-11-20T16:27:48Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78473', 'http://dx.doi.org/10.26153/tsw/5558']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Laser Melting,Level Set Methods for Modeling Laser Melting of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f58a319b-8495-478d-9774-ee937a38a11c/download,,"The physical model describing heat transfer and melting taking place during and after the
interaction of a laser beam with a semi-infinite metal surface is based on the classical Stefan
problem with appropriately chosen boundary conditions to reflect direct selective laser sintering
of metals. A level set method for solving this problem is presented in this paper. From the results
of these computations, we obtain time evolution of solid-liquid interface and temperature
distribution.",,,,,,
"['Rodriguez, Carlos', 'Barraza, Sol', 'Diaz, Julio', 'Arrieta, Edel', 'Hernandez, Alejandro', 'Hicks, Adam', 'Wicker, Ryan B.', 'Medina, Francisco']",2023-02-09T18:56:35Z,2023-02-09T18:56:35Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117440', 'http://dx.doi.org/10.26153/tsw/44321']",eng,2022 International Solid Freeform Fabrication Symposium,Open,bell crank,Lightweight Additively Manufactured Bell Crank,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2adbc897-d45c-4847-83fe-3c7bec49607e/download,,"Due to the long service life of Air Force Legacy aircrafts, some companies that used to 
manufacture their components and spares are no longer able to do so. In this case, Additive Man-
ufacturing (AM) poses as a viable option to manufacture those spares when needed and even im-
prove their cost, weight, and performance. This project focuses on designing, building and testing 
of a bell crank, a largely needed spare part in these aircrafts, in order to achieve weight reduction 
and increased strength. The designing process was done using Fusion 360’s Generative Design, 
which can be tailored to produce different outcomes which satisfy the user’s needs. Fused Depo-
sition Modeling (FDM) was chosen for the manufacturing method with ABS chosen as the testing 
material. The components were tested using an adapted Instron 5900 Series. The initial testing 
phase served to show that a horizontal build proved to be the most optimal out of three orientations 
tested, while the second phase showed that the Bk_fpx design, which focused on strength, was the 
best performing due to its strength-to-weight ratio (29.7) and cost ($160). It is recommended that 
all this work is continued by the metal AM method laser powder bed fusion (LPBF) with compa-
nies such as Selective Laser Melting (SLM) using Aluminum since this method is capable of rapid 
prototyping and this material would help minimize the weight in the aircraft.",,,,,,
"['Meisel, Nicholas A.', 'Williams, Christopher B.', 'Druschitz, Alan']",2021-10-05T18:35:24Z,2021-10-05T18:35:24Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88401', 'http://dx.doi.org/10.26153/tsw/15340']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['indirect 3D printing', 'cellular structures', 'metal casting']",Lightweight Metal Cellular Structures via Indirect 3D Printing and Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b7fd9be-0631-47d2-8f14-16985aa834b4/download,University of Texas at Austin,"Cellular materials offer high strength accompanied by low-density and can offer high
stiffness, good impact-absorption, and thermal and acoustic insulation. In this paper, the authors
describe their progress towards exploring the use of metal casting into 3D printed sand molds for
creating cellular materials and sandwich panels. The use of 3D printing allows for the
fabrication of sand molds without the need for a pattern, and thus enables the creation of cellular
structures with designed mesostructure from a bevy of metal alloys. The quality-of-fill results
for several cast aluminum cellular parts of varying geometry are presented in this paper, along
with a discussion of overall truss diameter variation.",,,,,,
"['Roe, Matthew', 'Yang, Li']",2023-02-24T14:53:53Z,2023-02-24T14:53:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117526', 'http://dx.doi.org/10.26153/tsw/44406']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Interpenetrating design', 'cellular structure', 'design', 'experimentation investigation']",A Limited -Scale Expeirmental Invstigation of the Unit Cell Topology Effects on Interpenetrating Cellular Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1136dab8-c16b-4b88-8621-ee75e871d8d0/download,,"The interpenetrating cellular structure is a novel recent design concept that has been subjected to some 
preliminary research efforts in recent years. As there still exist relatively limited understanding of such 
design concept, the current work aimed to provide additional insights via experimental-based study. Several 
baseline cellular unit cell structures that follow multiple cellular unit cell topology design rules were 
included in the study, in order to investigate whether there exist significant design relationships between 
the cellular topology pairing and the resulting performance of the interpenetrating structures. In general, 
the interpenetrating designs did not result in synergetic performance reinforcement with elastic modulus, 
ultimate strength or energy absorption, except for specific cases. In most cases, the local strut interaction 
between the two component cellular structures appear to exert negative effects on the properties of the 
interpenetrating structures. The results tentatively suggest the need of additional research with such concept.",,,,,,
"Bolvie, Klas",2019-10-18T14:59:54Z,2019-10-18T14:59:54Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76230', 'http://dx.doi.org/10.26153/tsw/3319']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sinterstation,Limits of Loose Metal Powder Density in the Sinterstation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/705a41d3-b331-4e46-bc5f-268dd046baa7/download,,"The possibility to increase the density of applied metal powder in the Sinterstation has been
investigated by successive addition of smaller sized particle fractions to a base powder. The optimal
composition for each blend was determined experimentally, and their apparent densities were compared
to the densities after Sinterstation application. The principal limiting factors for the density of metal
powder in the Sinterstation were found to be the interparticle friction and the small sized particles’
tendency to form a suspension in the air. Finally, based on the evaluation of the different powder
compositions’ behavior, a practical upper limit of loose metal powder density was estimated to 86%,
when applied by a Sinterstation. The highest applied powder density in this investigation was a binary
blend with 68.60% relative density.",,,,,,
"['Poudel, Arun', 'Shamsaei, Nima', 'Shao, Shuai']",2021-12-06T22:17:48Z,2021-12-06T22:17:48Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90695', 'http://dx.doi.org/10.26153/tsw/17614']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['linear elastic finite element analysis', 'stress intensity factor', 'three-dimensional defects', 'effect of defect shape']",Linear Elastic Finite Element Calculations of Short Cracks Initiated from the Defects: Effect of Defect Shape and Size,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d4a56c56-4a01-463e-9e51-643ece00f52b/download,University of Texas at Austin,"The defects present in an additively manufactured component deteriorate its mechanical,
especially fatigue performance. During loading, these defects influence the stress concentration,
promote the fatigue crack initiation and thus, lead to a lower fatigue performance. In this study,
the effect of defect shape and size on the Mode-I stress intensity factor (KI) of the short cracks
initiating from both 2D and 3D internal defects was investigated using linear elastic finite element
analysis (FEA). The shape of the defect was varied by altering the aspect ratio (width/height) from
0 to 1. Later, the dimensionless results from FEA were utilized to calculate the SIF in defects with
half-span width of range 10-100 µm. As a result, the influence of defect shape on the SIF was only
observed in the short crack length regimes and the measure of SIF was observed to increase with
decreasing aspect ratio for a given crack length.",,,,,,
"['Ullett, Jill S.', 'Rodrigues, Stanley J.', 'Chartoff, Richard P.']",2018-11-02T15:11:22Z,2018-11-02T15:11:22Z,1995,Mechanical Engineering,doi:10.15781/T25H7CD0C,http://hdl.handle.net/2152/69333,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'laser cured polymer', 'photo-polymer cure']",Linear Shrinkage of Stereolithography Resins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82f4e828-c093-465a-8e41-ca892ca869a4/download,,"The linear shrinkage of an acrylate and an epoxy based stereolithography resin was
measured during cure. A helium-cadmium (He-Cd) laser cured strands of resin as is done in the
stereolithography process using two exposures. The exposure time was held constant while the
delay time between exposures was varied. It was found for both resins that the final cure depth and
linear shrinkage were a function of delay time",,,,,,
"['Cesarano TI, Joseph', 'Baer, Thomas A.', 'Calvert, Paul']",2018-11-16T17:09:14Z,2018-11-16T17:09:14Z,1997,Mechanical Engineering,doi:10.15781/T2NG4HB9B,http://hdl.handle.net/2152/70299,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['freeform fabrication', 'dense ceramics', 'structural ceramics']",Liquid Metal Jetting for Printing Metal Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c71be89c-c5d4-4c74-9f6b-68c1657f7c4c/download,,"Liquid Metal Jetting (LMJ) is solid freeform fabrication process for producing metal
mechanical parts and electronic interconnects. It is a technology similar to ink jet printing
where individual molten droplets are accurately printed. LMJ will produce metal parts on
demand from a CAD database with functional performance parameters similar to metal parts
produced by machining or casting. By controlling solidification rates and metal alloy
composition, LMJ is able to produce parts with unique properties such as metal matrices
and functionally graded materials. This paper will review the current status of LMJ and
future applications for this technology.",,,,,,
"['Kirchebner, Benedikt', 'Weidner, Christoph', 'Ploetz, Maximilian', 'Rehekampff, Christoph', 'Volk, Wolfram', 'Lechner, Philipp']",2024-03-26T21:25:41Z,2024-03-26T21:25:41Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124416', 'https://doi.org/10.26153/tsw/51024']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['liquid metal jetting', 'liquid salt jetting', 'support structures', 'additive manufacturing']",LIQUID METAL JETTING OF ALUMINUM PARTS WITH SALT SUPPORT STRUCTURES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a0f2ab6f-7f9d-46ba-9858-5c332ad9584c/download,University of Texas at Austin,"Liquid metal jetting (LMJ) bears the potential of being a fast part manufacturing
technology while using a cheap raw material. LMJ is a subtype of material jetting (MJT) and the
parts are built by successively depositing droplets of molten metal onto a build platform. For full
3D capability, support structures are necessary, which must be removed in subsequent processes.
In previous investigations, we proposed the usage of water-soluble salt as a support material,
selected a suitable salt, and analyzed the influence of this material on aluminum parts made in
LMJ. The present work shows a duplex MJT print head for processing aluminum alloys and KClNaCl salt. Various printing sequences and support structure strategies are compared. The results
show that the sequence of printing aluminum and salt is crucial. Furthermore, using thin layers of
the support material as a release layer appears promising.",,,,,,
"Crockett, R.S.",2018-11-14T17:06:06Z,2018-11-14T17:06:06Z,1996,Mechanical Engineering,doi:10.15781/T2RJ49F1Z,http://hdl.handle.net/2152/70242,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['stereodeposition', 'FDC', 'Advanced ceramics Research']",The Liquid-to-Solid Transition in Stereodeposition Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c715f069-efa3-4965-af2f-fc89d1bfebc7/download,,,,,,,,
"['Maxwell, James', 'Borse, Sandesh']",2018-12-06T21:05:50Z,2018-12-06T21:05:50Z,1997,Mechanical Engineering,doi:10.15781/T29W09K05,http://hdl.handle.net/2152/71428,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['micromachining', 'excimer lasers']",The LMP Process: Layered Metal Prototyping of Titanium from Condensed Thin-Films for Microelectromechanical Devices,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cf8328db-417c-495f-b198-3d7b033ce461/download,,"Layered prototyping of three-dimensional titanium micromechanical
components was demonstrated using selected area laser photolysis of liquid-phase
organo-metallic and metal halide thin films. Scanning KrF and
XeF excimer lasers were employed at 248 and 351 nm, respectively, generating
solid titanium traces from condensed precursor films. Multiple layers
were patterned to produce high-aspect ratio titanium lines. Laser pulse repetition
rate, scan rate, pulse energy, and layer thickness were related to the
resulting layer topography. This process is a first step toward layered metal
rapid prototyping ofelectronic packaging microstructures and microelectromechanical
systems.",,,,,,
"['Simmons, Jacob', 'Daeumer, Matthias', 'Azizi, Arad']",2021-11-11T16:36:46Z,2021-11-11T16:36:46Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90240', 'http://dx.doi.org/10.26153/tsw/17161']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser powder-bed fusion', 'additive manufacturing', 'thermal conductivity', 'thermal transport', 'stainless steel', '316L', 'metal 3D printing']",Local Thermal Conductivity Mapping of Selective Laser Melted 316L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f12fe49-486a-45c7-a47e-9db29b2beb66/download,University of Texas at Austin,"The variation in thermal conductivity of 316L stainless steel samples produced with
selective laser melting with a varying process parameters is investigated in the bulk and in the
microscale. A critical scan rate was observed, while holding all other process parameters constant,
above which the porosity started to rapidly increase. For the lowest-porosity sample, a local
thermal conductivity map was produced using frequency-domain thermoreflectance. The local
stainless steel thermal conductivity varied between 10.4 and 19.8 W/m-K. The average thermal
conductivity of the thermal conductivity map agrees within measurement uncertainty with flash
diffusivity measurements. The reduction in thermal conductivity with increasing scan rate is not
fully explained by the porosity. The average measured values are less than conventionally
produced bulk 316L due to the unique processing conditions of laser powder bed fusion, which
modifies the crystallographic texture and microstructure.",,,,,,
"['Raja, Sandeep', 'Court, Nadia', 'Sidhu, Jagjit', 'Tuck, Chris', 'Hague, Richard']",2021-09-30T14:23:43Z,2021-09-30T14:23:43Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88255', 'http://dx.doi.org/10.26153/tsw/15196']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Direct Write', 'Additive Manufacturing', 'polymer thick film inks', 'inkjet inks', 'curing kinetics']",Localised Broadband Curing of Directly Written Inks for the Production of Electrical Devices for Aerospace Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ad59c9b-166f-431b-b220-5d3227c45c64/download,University of Texas at Austin,"Direct Write (DW) technologies afford the possibility of printing electronics and
sensors directly onto structural components. This allows advantageous weight saving by
making good use of available space through conformal printing whilst adding functionality.
To enable DW fabrication of devices onto large aerospace structures a localised processing
method is required. This paper investigates the feasibility of using a broadband thermal spot
curing system for processing DW Inkjet and Polymer Thick Film (PTF) materials onto
composite structures. The characteristics of spot cured tracks were compared to conventional
oven cured tracks and were shown to exhibit equivalent resistances.",,,,,,
"['Paudel, Basil J.', 'Thompson, Scott M.']",2021-11-18T17:05:25Z,2021-11-18T17:05:25Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90430', 'http://dx.doi.org/10.26153/tsw/17351']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser-powder bed fusion', 'heat transfer', 'simulation', 'multi-pass', 'numerical methods']",Localized Effect of Overhangs on Heat Transfer During Laser Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c6a9a3b-2c2a-4dde-b416-2e419d5a1db2/download,University of Texas at Austin,"The current study concentrates on the effect of local part topology on heat transfer during the laser-powder
bed fusion (L-PBF) additive manufacturing (AM) process. The high heat flux diffusion (i.e. thermal
spreading) is numerically modeled and investigated for the L-PBF of a thin-walled part with various
negative draft angles (overhangs) and a thin wall of variable cross-sectional area. Scan-wise and layer-wise
manufacturing effects on heat transfer are quantified via peak melt pool temperature and resulting melt pool
morphology. These thermal metrics are used to understand the effect of overhang angles on the melt pool
mand the surface roughness traits of stainless steel 316L, Inconel 625 and Ti-6Al-4V parts. Both powder
effects and phase change within the melt pool are considered using approximate, reduced-complexity
techniques. The employed numerical model has been validated using data available in the literature. Results
demonstrate that the melt pool morphology and temperature distribution along build geometries with
negative draft angles are significantly different than those with positive draft angles.",,,,,,
"['Aggarangsi, Pruk', 'Beuth, Jack L.']",2020-03-05T20:01:06Z,2020-03-05T20:01:06Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80153', 'http://dx.doi.org/10.26153/tsw/7174']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Additive Manufacturing,Localized Preheating Approaches for Reducing Residual Stress in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/12a209fc-325d-4e69-a4b8-0b0dee085179/download,,"Uniform preheating can be used to limit residual stress in the solid freeform
fabrication of relatively small parts. However, in additive manufacturing processes,
where a feature is deposited onto a much larger part, uniform preheating of the entire
assembly is typically not practical. This paper considers localized preheating to reduce
residual stresses, building on previous work using a defined thermal gradient through the
part depth as a metric for predicting maximum final residual stress. The building of thinwalled structures is considered. Two types of localized preheating approaches are
compared, appropriate for use in laser- or electron beam-based additive manufacturing
processes. In evaluating the effectiveness of each approach, a simplified
thermomechanical model is used that can be related directly to analytical
thermomechanical models for thermal stresses in unconstrained thin plates. Results are
presented showing that one of the methods yields temperature profiles likely to yield
reduced residual stresses at room temperature. Mechanical model results confirm this,
showing a significant reduction in maximum stress values. A more complete
thermomechanical simulation of thin wall fabrication is used to verify the trends seen in
the simplified model results.",,,,,,
"['Abolmaali, Saina', 'Vinel, Alexander', 'Fox, Jason', 'Liu, Jia', 'Silva, Daniel', 'Shamsaei, Nima']",2021-12-01T23:10:48Z,2021-12-01T23:10:48Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90650', 'http://dx.doi.org/10.26153/tsw/17569']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'surface roughness', 'ANOVA test', 'extreme value theory']",Location and Orientation Dependency in Surface Roughness of Nickel Super Alloy 625 Parts: Statistical and Distributional Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1d21574-fc24-4d93-9f95-b7641f326e9c/download,University of Texas at Austin,"Surface roughness is an important characteristic of additively manufactured parts,
since it can impact various mechanical properties, such as friction or fatigue life. Further,
surface roughness can change significantly depending on a number of factors: part
geometry, location on the build platform, process parameters, or powder characteristics.
Generally, it has been previously established that printing angle has a significant effect
on surface roughness. In this study we reanalyze a dataset constructed based on Laser-Beam Powder Bed Fusion manufactured Nickel super alloy 625 parts. The goal is to
evaluate the effect of location and print orientation on the variability of surface roughness,
particularly relative to printing angle. Different combinations of location orientation-angles
factors are tested using analysis of variance (ANOVA), with some significant findings. In
addition, we further consider the question of characterizing surface roughness measures
as applied to additive manufacturing and explore distributional analysis (particularly
extreme value theory) as a way to qualify these measures.",,,,,,
"['Lee, Seungjong', 'Muhammad, Muztahid', 'Zheng, Jingyi', 'Shao, Shuai', 'Shamsaei, Nima']",2021-12-01T23:13:52Z,2021-12-01T23:13:52Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90651', 'http://dx.doi.org/10.26153/tsw/17570']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'AM', 'laser beam powder bed fusion', 'LB-PBF', 'surface roughness', 'stainless steel', 'fatigue']",Locational Dependency of Additively Manufactured Parts: Effects of Surface Roughness on Fatigue Behavior,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0df7228-778e-449c-9df9-55d2d8361b50/download,University of Texas at Austin,"Surface roughness (SR) can vary significantly among parts manufactured at different locations on
the same build platform because of the gas flow and powder recoating process in current laser
beam powder bed fusion (LB-PBF) technique. In this study, intra-build SR variation across
locations was investigated for LB-PBF 316L stainless steel. The build platform was divided into
4 quadrants to assess the location-dependent variation of SR. Uniaxial stress-controlled fatigue
tests were conducted using a servo-hydraulic system. The SR from the four quadrants was analyzed
using the one-way Analysis of Variance (ANOVA) method and further verified SR's location
dependency. Kruskal-Wallis test was also employed since Box-Cox transformed data failed to
meet the requirements of the ANOVA test. Kruskal-Wallis test revealed that there are statistically
significant differences in SR values across different locations. The results were validated using
fatigue test results and gas flow simulation results reported in literature.",,,,,,
"['Lang, Andrew', 'Castle, James', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Siddhardh Nadendla, Venkata Sriram']",2023-02-09T18:53:45Z,2023-02-09T18:53:45Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117439', 'http://dx.doi.org/10.26153/tsw/44320']",eng,2022 International Solid Freeform Fabrication Symposium,Open,regression analysis,Logistic regression classification to predict regional anomalies in nominally printed volume of separate test pieces,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c61eeb2e-df34-4f18-ab2a-e99ed4285855/download,,"Supervised machine learning techniques have struggled to accurately predict voxel-wise 
occurrence of anomalies in metal powder bed parts printed with optimal processing parameters. 
This work discusses a method to visualize machine learning model predictions in 3D to interrogate 
patterns in the predictions. A simple logistic regression classifier, with cross validation and an 
optimized classification threshold, is trained using synthetic in situ features, a machine parameter, 
and post-process output labels. The developed classifier is shown to outperform deep learning and 
boosted classifiers on the datasets used. Voxel-wise prediction performance is very low, but 3D 
representation of model predictions shows the developed model can predict anomalies in the 
correct region of the printed part. The practical use of the developed method is demonstrated by 
predicting the occurrence of anomalies in nominally printed volume using a model that had been 
trained on a dataset printed with induced defects.",,,,,,
"['Bagsik, A.', 'Schöppner, V.', 'Klemp, E.']",2021-10-06T20:50:05Z,2021-10-06T20:50:05Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88441', 'http://dx.doi.org/10.26153/tsw/15378']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'long-term ageing', 'tensile specimes', 'Ultem*9085']",Long-Term Ageing Effects on Fused Deposition Modeling Parts Manufactured with Ultem*9085,Conference paper,https://repositories.lib.utexas.edu//bitstreams/af65892f-a70e-40b9-948e-edba4bacaea4/download,University of Texas at Austin,"Relating to the direct manufacturing of end-use parts the knowledge about the effect of the long-term
ageing of Fused Deposition Modeling (FDM) parts is of particular importance. For this, tensile specimens were
stored for time periods of up to 52 weeks in two different conditions and the testing was conducted at different
temperatures within a temperature range of -60°C to +160°C. Further tests were made after the exposure in
multiple media. The parts were built up with the system “Fortus 400mc” from Stratasys with the material
Ultem*9085 in two different build directions, the strongest direction X (on its side) and the weakest build
direction Z (upright) and with the standard toolpath parameters of the Insight software version 7.0.",,,,,,
"['Schmid, M.', 'Woellecke, F.', 'Levy, G.N.']",2021-10-05T19:04:08Z,2021-10-05T19:04:08Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88410', 'http://dx.doi.org/10.26153/tsw/15349']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'automotive application', 'Duraform® DF', 'Duraform® HST SLS', 'sealants']",Long-Term Durability of SLS Polymer Components Under Automotive Application Environment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f38e519d-a3f8-4098-bde3-95893b088f17/download,University of Texas at Austin,"Selective Laser Sintering (SLS) is close to be accepted as a genuine production technique
(Additive Manufacturing). However, one problem restricting a more frequent specific use of
SLS-parts is the limited or unknown long-term or functional behaviour under particular
environmental conditions. In our specific case, for automotive applications, plastic materials can
get in contact with brake fluid and coolant. The behaviour of commercial SLS materials in
contact with these liquids must be qualified in advance for a successful implementation. This
contribution investigates the resistance of Duraform®
 DF and Duraform® HST SLS made parts in
contact with the cited automotive media. The testes were carried out for parts as of the machine
and in a post processed coated state. Distinctive Epoxy-, Silicon- and PVC-based sealant was
used. Gravimetric analyses and results of mechanical behaviour are presented with respect to
material, type of coating and immersion time.",,,,,,
"['Ali, Mohammad Alshaikh', 'Huseynov, Orkhan', 'Fidan, Ismail', 'Vondra, Fred']",2024-03-26T21:28:38Z,2024-03-26T21:28:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124417', 'https://doi.org/10.26153/tsw/51025']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'metal casting', 'fused filament fabrication', 'material extrusion', 'investment casting']",Lost-PLA Casting Process Development Using Material Extrusion with Low-Weight PLA,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a7abb66-3ce7-4f9c-a1e9-12e4ac9b2d7c/download,University of Texas at Austin,"The goal of this research is to develop a baseline procedure for lost-PLA casting process
of aluminum. Traditional Manufacturing techniques and Smart Manufacturing techniques have
their advantages and disadvantages. Integrating the traditional and modern aspects of
manufacturing enhances the capabilities of manufacturing. In this study, low-weight PLA is used
in a Material Extrusion (MEX) machine to fabricate sacrificial patterns for an aluminum lost-casting process. Different process parameters, after a calibration process, are tested for the MEX
process The MEX process parameters tested are: infill pattern, and top/bottom solid layers. The
MEX process parameter investigation allows to draw conclusions to establish a standard for which
parameters are ideal for the casting process. For this research, casting process parameters are set
constant. The preliminary studies show that the lost-PLA casting process is successful in producing
dimensionally accurate aluminum parts by a direct-pour casting process using the suggested MEX
process parameters.",,,,,,
"['Hume, Chad A.', 'Rosen, David W.']",2021-11-15T20:42:36Z,2021-11-15T20:42:36Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90264', 'http://dx.doi.org/10.26153/tsw/17185']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['numerical modeling', 'methodology', 'predictive models', 'material jetting', 'material jetting-based additive manufacturing']",Low Cost Numerical Modeling of Material Jetting-Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dd39aae1-82b9-4150-b3e7-67b3fa5cdcf5/download,University of Texas at Austin,"Material jetting-based additive manufacturing is a promising manufacturing approach
with increasing interest in mesoscale applications such as microfluidics, membranes, and
microelectronics. At these size scales, significant edge deformation is observed limiting the
resolvable feature size. Currently, predicting and controlling such deformations would require
extensive experimentation or computationally prohibitive simulations. The objective of this work
is to develop a computationally low cost material jetting model that enables the simulation and
prediction of mesoscale feature fabrication. To this end, a quasi-static boundary-based method is
proposed and demonstrated as a simplified and accurate means of predicting the line-by-line,
layer-by-layer feature development. The method is validated through comparison with the known
analytical solution for a single droplet; then the method’s application to AM is demonstrated
through modeling of representative mesoscale features. The benefits and limitations of each are
discussed.",,,,,,
"['Barrett, Christopher', 'Carradero, Carolyn', 'Harris, Evan', 'McKnight, Jeremy', 'Walker, Jason', 'MacDonald, Eric', 'Conner, Brett']",2021-11-15T21:59:26Z,2021-11-15T21:59:26Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90285', 'http://dx.doi.org/10.26153/tsw/17206']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['spatter tracking', 'stereovision', 'low cost', 'high speed', 'cameras', 'laser powder bed fusion']","Low Cost, High Speed Stereovision for Spatter Tracking in Laser Powder Bed Fusion",Conference paper,https://repositories.lib.utexas.edu//bitstreams/8661556e-585e-4687-a941-86d0cdc81190/download,University of Texas at Austin,"Powder Bed Fusion Additive Manufacturing affords new design freedoms for metallic
structures with complex geometries in high performance materials. The aerospace industry has
identified the inherent benefits of AM not just in terms of shape creation but also with regard to
producing replacement parts for an aging fleet of aircraft. However, for these parts to be deployed
in flight-critical applications, the quality must be well established given the lack of flight heritage
for the manufacturing process. As additive manufacturing is executed layerwise, opportunities
exist to non-destructively verify the fabrication in situ with a qualify-as-you-go methodology. In
this study, a pair of low cost, high speed cameras are integrated and synchronized together to
provide stereovision in order to identify the size, speed, direction and age of spatter ejected from
the laser melt pool. The driving hypothesis of the effort is that behavior of spatter can be reliably
measured in order to determine the health of the laser process and ensure that spatter is not
contaminating the build. Feasibility demonstrations are shown that describe how the
measurements are made and characteristics calculated from the image data and how the data
were verified with alternative measurements. Opportunities, future work and challenges are
discussed.",,,,,,
"['Ullett, J. S.', 'Chartoff, R. P.', 'Schultz, J. W.', 'Bhatt, J. C.', 'Dotrong, M.', 'Pogue, R. T.']",2018-11-15T20:52:32Z,2018-11-15T20:52:32Z,1996,Mechanical Engineering,doi:10.15781/T27D2QT2J,http://hdl.handle.net/2152/70279,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['high performance resins', 'dimensional accuracy', 'stereolithography']","Low Shrinkage, High T Liquid Crystal Resins For Sterelithography",Conference paper,https://repositories.lib.utexas.edu//bitstreams/5f6def77-ca29-4aaf-a1f3-915b07c26efc/download,,,,,,,,
"['Yamauchi, Yuki', 'Kigure, Takashi', 'Niino, Toshiki']",2021-11-01T21:45:00Z,2021-11-01T21:45:00Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89765,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['PA powder', 'fiber laser', 'low temperature laser sintering']",Low Temperature Laser Sintering of PA Powder Using Fiber Laser,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2c821765-8de5-4f29-9937-107ca2643969/download,University of Texas at Austin,"Low temperature process is a novel plastic laser sintering process having potential for improving
powder recyclability dramatically. Although fiber laser has been rarely used for plastic laser
sintering in commercial base, its ability of being focused in a very small spot suits it to improve
precision of plastic laser sintering. In this research, low temperature laser sintering using fiber laser
was tested. The highest part density of 99% was obtained while standard high temperature process
can provide only 81%. Although generation of fume, which is a major problem in low temperature
process using CO2 laser, is not suppressed, it did not affect quality of parts. Part density was
strongly affected by slice size of parts and improved when the size is reduced.",,,,,,
"['Menge, D.', 'Schmid, H.-J.']",2021-12-01T23:46:40Z,2021-12-01T23:46:40Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90662', 'http://dx.doi.org/10.26153/tsw/17581']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['low temperature laser sintering', 'laser sintering system', 'laser sintering', 'PA12']",Low Temperature Laser Sintering on a Standard System: First Attempts and Results with PA12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15054e14-1008-4385-8325-98893b2a9b31/download,University of Texas at Austin,"The laser sintering process has been a well-established AM process for many years.
Disadvantages of LS are the low material variety and the thermal damage of the unprocessed
material. The low temperature laser sintering attacks at this point and processes powder material at
a build chamber temperature lower than the recrystallization temperature. This drastic reduction in
temperature results in significantly less thermal damage to the material. This work deals with the
low temperature laser sintering of Polyamide 12 (PA12) on a commercial, unmodified laser
sintering system to compare it to standard laser sintered PA12 and to create the basis for low
temperature laser sintering of high temperature materials on such a system. First results by
changing the exposure parameters and by fixing parts on a building platform show a processing of
PA12 on an EOS P396 at a build chamber temperature less than 100 °C instead of standard approx.
175 °C.",,,,,,
"['Niino, Toshiki', 'Uehara, Takashi']",2021-10-21T14:55:22Z,2021-10-21T14:55:22Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89385,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['plastic laser sintering', 'warpage', 'PEEK', 'temperature', 'powder bed']",Low Temperature Selective Laser Melting of High Temperature Plastic Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97895c28-4025-4ca4-99ee-55274f5d75ee/download,University of Texas at Austin,"In a typical plastic laser sintering or melting system, powder bed temperature is
maintained above the recrystallization temperature of the powder material to prevent
the parts under process from warping until the whole layers are processed. Although this
countermeasure can elegantly suppress the part warpage, heating the powder bed to
such a high temperature causes many problems. In case of high temperature plastic such
as polyetheretherketone (PEEK), bed temperature should be more than 300°C. Due to
this requirement, machine cost is extremely high and powder recyclability is very low.
The authors had introduced another countermeasure for the part warpage that anchors
the in-process parts to a rigid base plate instead of heating the powder bed above the
recrystallization temperature. In the current research, application of this method to
PEEK powder is tested, and a simple test piece of which relative density is more than
90% was successfully obtained with preheating temperature of 200°C. In this paper,
mechanical performances of obtained parts are presented, and several problems with the
process of PEEK powder are discussed as well.",,,,,,
"['Chen, Jingdong', 'Smith, Douglas E.']",2021-11-18T19:13:13Z,2021-11-18T19:13:13Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90474', 'http://dx.doi.org/10.26153/tsw/17395']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['melt flow', 'polymer filaments', 'low-cost', 'fused filament fabrication', 'additive manufacturing']",A Low-Cost Approach for Characterizing Melt Flow Properties of Filaments Used in Fused Filament Fabrication Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a74c07bd-06f9-4d96-8856-16b204b8539b/download,University of Texas at Austin,"Users of Fused Filament Fabrication (FFF) can choose from a wide variety of new materials as
filament producers continue to introduce new polymer and polymer composite filament into the
marketplace. This paper describes a low-cost device capable of measuring the rheological
properties of off-the-shelf polymer filament. In this approach, measurements are taken during
filament extrusion which are combined with a pressure drop model based on simple shear flow
within the FFF nozzle to perform inverse analysis that computes parameters for the power law
generalized Newtonian fluid (GNF) model. The applicability of our FFF-filament rheometer is
demonstrated with four commercially available polymer filaments by comparing the results to
those obtained from a commercial rotational rheometer. A filament characterization approach
similar to Melt Flow Index (MFI) is also proposed to assess the extrusion characteristics of
materials specific to FFF.",,,,,,
"['Gibson, Ian', 'Ming, Ling Wai']",2018-11-28T19:25:58Z,2018-11-28T19:25:58Z,1997,Mechanical Engineering,doi:10.15781/T2ZG6GS99,http://hdl.handle.net/2152/70326,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'Process control']",Low-cost Machine Vision Monitoring of the SLS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d6d815a1-9dd1-41e4-b50f-919bd1b575aa/download,,"During the building of a part using SLS, it is common practice to adjust the temperature
parameters. It is important to control these parameters because ifthey are too high then part
breakout is difficult. Ifthey are too low then parts have poor material properties. One method of
controlling these parameters is by observation through the process chamber window. Any
adjustment can be determined by examining the colour ofthe cross-section in process. By using a
machine vision system to determine colour variation, it is possible to calculate temperature or
laser power adjustments necessary to maintain consistent part quality.",,,,,,
"['Mathewson, Brian B.', 'Hebbar, Ravi', 'Choi, Sangeun', 'Newman, Wyatt S.', 'Cawley, James D.', 'Heuer, Arthur H.']",2019-02-22T19:55:34Z,2019-02-22T19:55:34Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73467', 'http://dx.doi.org/10.26153/tsw/617']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAM-LEM', 'layer-to-Iayer']","Machine Design, Control and Performance of Automated Computer-Aided Manufacturing of Laminated Engineering Materials",Conference paper,https://repositories.lib.utexas.edu//bitstreams/efab630e-29ca-4906-841e-40a8b4109944/download,,"This paper describes machine design and control aspects of automating a viable
CAM-LEM layered manufacturing process. The cut-then-stack sheet-based approach permits
using sheet materials of different thicknesses, enabling optimization of build speed. Further,
this cut-then-stack approach offers the possibility of assembling parts with multiple materials
interleaved both layer-to-Iayer as well as within each layer. The key to realizing these
prospective advantages is precise and reliable extraction and assembly of laser-cut regions
from sheet feedstock. This paper presents our design approach and examples created on an
automated CAM-LEM machine. It will be shown that the use of fugitive materials,
automatically assembled interleaved with engineering materials, is feasible, allowing
fabrication of laminated components with internal cusps and voids and improving the
dimensional stability of components during post-processing. Results of this work are
presented and applications of the technology are reviewed. Extensions to tangent-cut
thick-sheet interleaved assemblies are described.",,,,,,
"['Hilton, Z.T.', 'Gray, Jamee']",2023-04-03T15:35:23Z,2023-04-03T15:35:23Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117716', 'http://dx.doi.org/10.26153/tsw/44595']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Laser powder bed fusion,Machine Health Verification Process for Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e5a24ce-6396-4287-9a45-1073e1bd9635/download,,"Laser powder bed fusion (LPBF) machines are complex systems comprised of a number of 
interconnected subsystems which work in concert during the laser powder bed fusion process. 
The health, i.e. consistency in performance, of these complex systems must be monitored and 
verified to ensure consistency in the process during long-term production. If a system is 
'unhealthy' the process becomes less controlled and can lead to decreased, unknown, or 
unverifiable part quality. To monitor and validate whether  a machine is healthy, a number of 
tests were developed, which consist of: power monitoring, multi-laser alignment, laser position, 
laser caustic, gas flow, elevator accuracy, and machine condition. The methodology and efficacy 
of each test are discussed along with additional potential tests and next steps.",,,,,,
"Beaman, Joseph J.",2018-04-19T18:42:12Z,2018-04-19T18:42:12Z,1992,Mechanical Engineering,doi:10.15781/T2FX74F7X,http://hdl.handle.net/2152/64413,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'CAD representation', 'Selective Laser Sintering', 'SLS']",Machine Issues Associated with Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7b752b4c-0bbe-40d5-87a7-e3803639884c/download,,"Before we begin a discussion of machine issues it is important that we categorize
exactly what we mean. There are differences between the design of a research piece of
equipment as compared to a commercial piece of equipment. A research piece of
equipment has to have the flexibility to demonstrate a success pattern. A commercial
piece of equipment, on the other hand, assumes that you have a stable platform and you
are now trying to assess how broad a success path you have (Figure 1). In fact, you are
trying to make that path as broad as possible so that the machine will not fail and will
always work the same way. This particular talk, and my expertise, is much more along
the lines of design of a research piece of equipment. What I will be talking about today
are machine issues associated with developing a success path in Solid Freeform
Fabrication. The machines we will be talking about have to have the flexibility to operate
in a wide variety of ways with a wide variety of experiments.",,,,,,
"['Wang, Jier', 'Panesar, Ajit']",2024-03-27T15:47:15Z,2024-03-27T15:47:15Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124489', 'https://doi.org/10.26153/tsw/51097']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['metamaterial', 'machine learning', 'additive manufacturing']",Machine Learning Assisted Mechanical Metamaterial Design for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f30fe5c2-03cf-4945-914e-9bec268a4692/download,University of Texas at Austin,"Metamaterials, widely studied for its counterintuitive property such as negative Poisson’s ratio, negative
refraction, negative thermal expansion, and employed in various fields, are recognised to provide foundation for
superior multiscale structural designs. However, current mechanical metamaterial design methods usually relay
on performing sizing optimisations on predefined topology or implementing time-consuming inverse
homogenisation methods. Machine Learning (ML), as a powerful self-learning tool, is considered to have the
potential of discovering metamaterial topology and extending its property bounds. This work considers the use
of Neural Networks (NNs), (De-Convolutional Neural Networks) DCNNs and Generative Adversarial Networks
(GANs) to speed up the generation of new topologies for metamaterials. NNs and DCNNs are trained to inversely
generate metamaterial designs based on the input target effective macroscale properties, whilst the generator in
GANs is expected to output diverse metamaterial microstructures with random noise inputs. This work highlights
the potential of data-driven approaches in Design for Additive Manufacturing (DfAM) as an alternative to the
time-consuming, conventional methods.",,,,,,
"['Wang, J.', 'Panesar, A.']",2021-12-01T21:14:26Z,2021-12-01T21:14:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90614', 'http://dx.doi.org/10.26153/tsw/17533']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'machine learning', 'neural network', 'finite element']",Machine Learning Derived Graded Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44e74772-3b48-4e18-a066-42d6dcd6486b/download,University of Texas at Austin,"Herein, we propose a new lattice generation strategy that is computationally cheaper and produces high-quality geometric definition based on Machine Learning (ML) when compared to traditional methods. To
achieve the design of high-performance unit cells, firstly, the optimal mechanical property for each cell region
is derived according to the loading condition and the reference density obtained utilising a
conventional topology optimisation result. Next, a Neural Network (NN) is employed as an inverse generator
which is responsible for predicting the cell pattern for the optimal mechanical property. Training data (~ 500)
were collected from Finite Element (FE) analysis with varied cell parameters and then fed to the NN. With the
help of ML, the time spent in building the inverse generator is significantly reduced. Furthermore, the ML-based inverse generator can handle different cell types rather than one specific type which facilitates the
diversity and optimality of lattices.",,,,,,
"['Zhang, Wentai', 'Mehta, Akash', 'Desai, Prathamesh S.', 'Higgs, C. Fred III']",2021-11-03T21:43:39Z,2021-11-03T21:43:39Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89941,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing (AM)', 'powder spreading process map', 'discrete element method', 'machine learning']",Machine Learning Enabled Powder Spreading Process Map for Metal Additive Manufacturing (AM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/dfc8b05c-4978-4ad7-b992-60178e92f62a/download,University of Texas at Austin,"The metal powder-bed AM process involves two main steps: the spreading of powder layer and
selective fusing or binding the spread layer. Most AM research is focused on powder fusion.
Powder spreading is more rarely studied but is of significant importance for considering the quality
of the final part and total build time. It is thus essential to understand how to modify the spread
parameters such as spreader speed, to generate layers with desirable roughness and porosity. A
computational modeling framework employing Discrete Element Method (DEM) is applied to
simulate the spreading process, which is difficult to study experimentally, of Ti-6Al-4V powder
onto smooth substrates. Since the DEM simulations are computationally expensive, machine
learning was employed to interpolate between the highly non-linear results obtained by the running
a few DEM simulations. Eventually, a spreading process map is generated to determine which
spreader parameters can achieve the desired surface roughness and spread speed. This eventually
saves the total time for printing and reduces the cost of build.",,,,,,
"['Petrich, Jan', 'Gobert, Christian', 'Phoha, Shashi', 'Nassar, Abdalla R.', 'Reutzel, Edward W.']",2021-11-03T22:29:31Z,2021-11-03T22:29:31Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89950,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['machine learning', 'defect detection', 'high resolution layerwise imaging', 'post-build CT scans', 'powder bed fusion additive manufacturing']",Machine Learning for Defect Detection for PBFAM Using High Resolution Layerwise Imaging Coupled with Post-Build CT Scans,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3d372929-9f3b-4aab-ae88-80276de95582/download,University of Texas at Austin,"This paper develops a methodology based on machine learning to detect defects during
Powder Bed Fusion Additive Manufacturing (PBFAM) processes using data from high resolution
images. The methodology is validated experimentally using both a support vector machine (SVM)
and a neural network (NN) for binary classification. High resolution images are collected each
layer of the build, and the ground truth labels necessary for supervised machine learning are
obtained from a 3D computed tomography (CT) scan. CT data is processed using image processing
tools—extended to 3D—in order to extract xyz position of voids within the component. Anomaly
locations are subsequently transferred from the CT domain into the image domain using an affine
transformation. Multi-dimensional features are extracted from the images using data surrounding
both anomaly and nominal locations. Using cross-validation strategies for machine learning and
testing, accuracies of close to 90% could be achieved when using a neural network for in-situ
anomaly detection.",,,,,,
"['He, Haiyang', 'Yang, Yang', 'Pan, Yayue']",2021-11-09T14:56:58Z,2021-11-09T14:56:58Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90088', 'http://dx.doi.org/10.26153/tsw/17009']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['continuous projection stereolithography', 'CLIP', 'machine learning', 'deep neural network', 'siamese network', 'continuous printing speed']",Machine Learning for Modeling of Printing Speed in Continuous Projection Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a159aa64-d973-44a0-ad63-79f6a61eac96/download,University of Texas at Austin,"Continuous projection stereolithography technologies, also known as the Continuous Liquid Interface
Production (CLIP), can achieve build speeds an order of magnitude faster than conventional layer-by-layer
stereolithography process. However, identification of the proper continuous printing speed remains a grand
challenge in the process planning. To successfully print a part continuously, the printing speed needs to be
carefully adjusted and calibrated for the given geometry. In this paper, we investigate machine learning techniques
for modeling and predicting the proper printing speed in the continuous projection stereolithography process. The
synthetic dataset is generated by physics-based simulations. Experimental dataset is constructed for training the
machine learning models to find the appropriate speed range and the optimum speed. Conventional machine
learning techniques including Decision Tree, Naïve Bayes, Nearest Neighbors, and Support Vector Machine
(SVM), ensemble methods including Random Forest, Gradient Boosting, and Adaboosting, and the deep learning
approach Siamese Network are tested and compared. Experimental results validate the effectiveness of these
machine learning models and show that the Siamese Network model gives the highest accuracy.",,,,,,
"['Pike, J.A.', 'Klett, J.', 'Kunc, V.', 'Duty, C.E.']",2023-04-03T17:49:25Z,2023-04-03T17:49:25Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117731', 'http://dx.doi.org/10.26153/tsw/44610']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Machine Learning in Additive Manufacturing: A Review of Learning Techniques and Tasks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a21c73e-897f-4f63-8c5e-3b411f49bc7a/download,,"Due to recent advances, Machine Learning (ML) has gained attention in the Additive 
Manufacturing (AM) community as a new way to improve parts and processes. The capability of 
ML to produce insights from large amounts of data by solving tasks such as classification, 
regression, and clustering provide possibilities to impact every step of the AM process. In the 
design phase, ML can optimize part design with respect to geometry, material selection, and part 
count. Prior to printing, process simulations can offer understanding into the how the part will be 
printed, and energy, time, and cost estimates of a print can be made to assist with resource 
planning. During printing, AM can benefit from in-situ printing optimization and quality 
monitoring. Lastly, ML can characterize printed parts from in-situ or ex-situ data. This article 
describes some of the ML learning techniques and tasks commonly employed in AM and provides 
examples of their use in previous works.",,,,,,
"['Rajeshirke, Mithila', 'Alkunte, Suhas', 'Huseynov, Orkhan', 'Fidan, Ismail']",2024-03-25T22:43:47Z,2024-03-25T22:43:47Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124327', 'https://doi.org/10.26153/tsw/50935']",en_US,1990 International Solid Freeform Fabrication Symposium,open,"['material extrusion', 'fatigue prediction', 'composites', 'machine learning', 'additive manufacturing']",Machine Learning-Assisted Prediction of Fatigue Behaviour in Fiber-Reinforced Composites Manufactured via Material Extrusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fb9e9b1-9db1-404a-80c7-31667917f322/download,University of Texas at Austin,"The recent advancements in material extrusion (MEX) have expanded the potential use of
polymeric and composite structures in a wide range of structural and load-bearing applications.
However, cyclic loads can induce fatigue, resulting in the development of structural damage and
potentially leading to catastrophic failure at lower stress levels compared to normal mechanical
loading. Therefore, it is crucial to thoroughly investigate and understand the fatigue behavior of
composite parts manufactured using MEX. Predicting the fatigue life of polymeric composite
components poses a significant challenge due to the complex nature of the materials involved. In
this research, the aim is to utilize Machine Learning (ML) techniques to predict the fatigue life of
fiber-reinforced composites produced through the MEX process. ML focuses on developing
models that can learn from data, recognize underlying patterns within the data, and use those
patterns to make accurate predictions or decisions.",,,,,,
"['Mondal, Sudeepta', 'Menon, Nandana', 'Ray, Asok', 'Basak, Amrita']",2023-01-26T15:37:49Z,2023-01-26T15:37:49Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117319', 'http://dx.doi.org/10.26153/tsw/44200']",eng,2022 International Solid Freeform Fabrication Symposium,Open,nickel-base alloys,Machine Learning-Assisted Prediction of Thermophysical Properties of Nickel-Base Alloys over a Temperature Range,Conference paper,https://repositories.lib.utexas.edu//bitstreams/58f3b0a2-3b84-4391-9b45-fd2f6a40b382/download,,"Calculation of thermophysical properties of complex metallic alloys as functions of composition 
and temperature is essential to design new alloy systems that are suitable for advanced 
manufacturing processes such as additive manufacturing. Once the properties are obtained, they 
are typically integrated with a meso-scale simulation framework to understand the impact of 
composition on different properties. While the forward problem is straight forward, the inverse 
problem necessitates the integration of the thermodynamic and meso-scale modeling with an 
optimization framework. The usage of machine learning (ML) tools is, therefore, deemed to be 
conducive to the development of a digital twin framework for both thermodynamic as well as 
meso-scale modeling. This paper implements a Gaussian Process (GP) framework to predict 
thermophysical properties (e.g., bulk density, solidus/liquidus temperatures) of a nickel-base 
metallic alloy system, nickel-chromium-aluminum (Ni-Cr-Al), over a temperature range. The 
results show that the proposed GP-based framework is conducive to predicting thermophysical 
properties with good accuracy and, thus, can be implemented as a surrogate in the digital twin 
development of additive manufacturing processes.",,,,,,
"['Hayasi, Mohammad T.', 'Asiabanpour, Bahram']",2021-09-23T20:44:48Z,2021-09-23T20:44:48Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88023', 'http://dx.doi.org/10.26153/tsw/14964']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['machine path generation', 'direct slicing', 'design-by-feature', 'feature recognition']",Machine Path Generation Using Direct Slicing from Design-by-Feature Solid Model for Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be4ff441-f196-41d3-8300-e45bc7df5c9a/download,,"Because of the differences in the rapid prototyping (RP) processes, there is no standard machine path
code for them. For each RP process, based on its characteristics and requirements, the required data
are extracted from the CAD model and converted into proper format for the RP machine. Slicing a
CAD model through intersecting the model with the XY-plane at each Z increment is a well-known
method of path generation. Slicing a CAD model is currently conducted through Stereolithography
(STL) file slicing, direct slicing, and additive direct slicing. In this paper, a direct slicing approach
inside a design-by-feature solid modeler is proposed. Autodesk Inventor solid modeler, as a design-by-feature solid modeler is used for 3D solid modeling. The proposed system is implemented by
Visual Basic codes inside Inventor. In this approach, first protrusion and subtractive features that form
a model are extracted. Then, the intersection of each feature and the XY plane is identified. Then,
internal and external loops are found. Finally a continuous path in required format is generated.
Depending on the specific RP process requirements, additional features such as internal or external
hatch can be added to the machine path.",,,,,,
"['Kmecko, I.S.', 'Kovacevic, R.', 'Jandric, Z.']",2019-09-23T17:29:42Z,2019-09-23T17:29:42Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75985', 'http://dx.doi.org/10.26153/tsw/3084']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Machine Vision Based Control of Gas Tungsten Arc Welding for Rapid Prototyping 578,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0750d482-2891-4f3d-9d83-4481d221902e/download,,"A machine vision system, based on CCD camera, is used to control the molten pool size during the gas tungsten arc welding (GTAW) process. The technique is tested by making a metallic part with a complex 3-D network of conformal channels on a hybrid rapid prototyping machine based on welding and milling. The test part demonstrated manufacturing flexibility and new technological opportunities required for prototyping injection mold tools. The real metallic part made in a layered fashion had good surface quality, dimensional accuracy, and high density.","This work was financially supported by THECB’s Grants No. 0036133-0005-1997 and 003613- 0022-1999, NSF’s Grants No DMI-9732848 and DMI-9809198, and by the U.S. Department of Education Grant No. P200A80806-98.",,,,,
"['Koivunen, V.', 'Bajcsy, R.']",2018-05-03T19:43:14Z,2018-05-03T19:43:14Z,1993,Mechanical Engineering,doi:10.15781/T2154F62N,http://hdl.handle.net/2152/65068,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['CAD systems', 'CAD model', 'NURBS']",Machine Vision for Rapid Geometric Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c74cf0ac-162a-423a-aa7a-b2a4606b0967/download,,,,,,,,
"['Arigbabowo, Oluwasola K.', 'Tate, Yash', 'Geerts,  Wilhelmus J']",2024-03-25T22:26:42Z,2024-03-25T22:26:42Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124321', 'https://doi.org/10.26153/tsw/50929']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['magnetic fillers', 'Polyamide 4.6', 'Twin Screw Extrusion', 'additive manufacturing']",MAGNETIC CHARACTERIZATION OF 3D PRINTED HIGHPERFORMANCE POLYAMIDE MAGNETIC COMPOSITE,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11f6abd5-317c-4dbd-877b-da1df4282107/download,University of Texas at Austin,"Polyamide 4.6 is classified as a high-temperature thermoplastic because of its service
temperatures of up to 175°C, bringing it close to high-temperature plastics like PPS or PEEK. Due
to its high-temperature capability and price/performance ratio, Polyamide 4.6 is considered viable
in developing high-performance bonded magnets by serving as a binder/matrix to magnetic
powders/fillers to form multifunctional magneto polymeric composites that offer superior
properties to conventional materials. In this research, 10 wt.% and 30 wt.% strontium ferrite
magnetic powders were compounded with polyamide 4.6 using a co-rotating twin screw extruder
to fabricate monofilament bonded magnets for 3D printing. Morphological and magnetic
characterization was performed on the 3D printing monofilament samples using Scanning Electron
Microscopy, and Vibrating Sample Magnetometer, respectively. The morphological observations
showed an even dispersion of the strontium ferrite fillers in the magnetic composite. The magnetic
hysteresis results obtained via the VSM measurement at elevated temperatures indicate that the
polyamide 4.6 binder was durable enough to keep the magnetic particles from moving in the
bonded magnets. This suggests that the strontium ferrite bonded with Polyamide 4.6 binder is a
much better composite and can be used in high-temperature applications up to 150 °C.",,,,,,
"['Sukhotskiy, V.', 'Karampelas, I.H.', 'Garg, G.', 'Verma, A.', 'Tong, M.', 'Vader, S.', 'Vader, Z.', 'Furlani, E.P.']",2021-11-04T15:14:26Z,2021-11-04T15:14:26Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89984', 'http://dx.doi.org/10.26153/tsw/16905']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['magnetohydrodynamics', 'droplet ejection', 'drop on demand printing', '3D printing', 'additive manufacturing', 'thermo-fluidics', 'molten aluminum']",Magnetohydrodynamic Drop-on-Demand Liquid Metal 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ad6bcde5-c808-4a51-bac1-dde0ea1699e0/download,University of Texas at Austin,"We present a novel method for liquid metal drop-on-demand (DOD) additive manufacturing
of three-dimensional (3D) solid metal structures. This method relies on magnetohydrodynamic
(MHD)-based droplet generation. Specifically, a pulsed magnetic field, supplied by an external
coil, induces a Lorentz force density within a liquid metal filled ejection chamber, which causes a
droplet to be ejected through a nozzle. Three-dimensional solid metal structures of arbitrary shape
can be printed via layer-by-layer patterned deposition of droplets with drop-wise coalescence and
solidification. We introduce this prototype MHD printing system along with sample printed
structures. We also discuss the underlying physics governing drop generation and introduce
computational models for predicting device performance.",,,,,,
"['Wang, W. L.', 'Fuh, J. Y. H.', 'Wong, Y. S.', 'Miyazawa, T.']",2018-11-14T17:41:15Z,2018-11-14T17:41:15Z,1996,Mechanical Engineering,doi:10.15781/T23R0QD14,http://hdl.handle.net/2152/70247,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLA process', 'rapid prototyping', 'manufacturing processes']",Make-up Fabrication of Big or Complex Parts Using the SLA Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc726201-c6b2-4836-9302-9a6a06b59671/download,,"Rapid prototyping is a highly flexible manufacturing technology which can produce big or
complex parts without any special fixtures and tools. But it is often a costly and time consuming
process to produce big and complex parts. To solve this problem, this paper proposes the makeup
fabrication process. The process cuts the CAD models of big or complex parts into several
small components. optimizes the building orientation and the layout of the multiple objects and
then uses theSLA process to build. The paper discusses the basic process, the discretion rules of
the CAD models and the optimization of the layout of multiple objects in the simultaneous
building",,,,,,
"['Malyala, Santosh Kumar', 'Gibson, Ian', 'Y, Ravi Kumar', 'Chakravarthy, Chitra']",2021-11-09T20:59:28Z,2021-11-09T20:59:28Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90164', 'http://dx.doi.org/10.26153/tsw/17085']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'AM', 'mandibular resection', 'reposition appliance', 'complex surgery']",Mandibular Repositioning Appliance Following Resection Crossing the Midline- A3D Printed Guide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e062236e-b20b-4d8e-8215-bed261915ef3/download,University of Texas at Austin,"Additive Manufacturing (AM) is one of the latest manufacturing processes which has evolved
dramatically over the past three decades. The benefits of AM have steadily stepped in to almost
all modern industries. The medical and dental industries may have benefitted the most in this
regard. In the medical industry, every complex surgery has unique requirements in planning or
execution, where it needs customized surgical guides or tools. In patients with mandibular
tumors where a surgical resection is performed crossing the midline, currently there is no guide
or tool available for repositioning the mandible to the patient’s original anatomy. To overcome
this, an attempt has been made to develop a customized repositioning appliance, which can be
used for pre surgical planning and the same can be transferred to the patient during surgery. The
repositioning appliance is developed using the patient's CT data which is then processed with the
use of medical translation software. The final patient specific repositioning appliance is
fabricated using AM technology. This guide has been used on the models of the jaws requiring
resection to check their efficacy and the condylar repositioning has been seen to be close to the
pre-surgical position. This appliance is useful for pre-surgical planning, pre-bending and
adaptation of the reconstruction plate to the mandible and also to reposition the condyles to their
original positions after the resection.",,,,,,
"['Trautschold, Olivia', 'Dong, Andy']",2021-12-07T17:16:23Z,2021-12-07T17:16:23Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90725', 'http://dx.doi.org/10.26153/tsw/17644']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['crumple-forming', 'additive manufacturing', 'manufacturability analysis', 'complex network theory', 'eigenvalue decomposition']",Manufacturability Analysis of Crumple-Formed Geometries through Reduced Order Models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f445a359-62ba-435a-bdd2-9d5394606379/download,University of Texas at Austin,"Crumple-formed structures have irregular, multiscale geometric complexity. Similar to
periodic lattices, crumpled geometries can be tailored to applications requiring a high strength-to-weight ratio. As an alternative to confinement-based crumple forming, additive manufacturing
allows for increased geometric control and structural reproducibility to fabricate these structures.
The inherently irregular geometries of crumple-formed structures decrease the sensitivity of
macroscale properties to microscale manufacturing defects but pose a unique challenge for the
analysis of manufacturability using additive processes. Current approaches to manufacturability
analysis lack techniques suitable for addressing the multiscale geometric complexity and
irregularity of crumpled structures. This paper presents a preliminary study into the
manufacturability of crumple-formed structures using a model reduction technique that preserves
the robust bulk statistical properties of crumpled structures. Manufacturability predicted by the
reduced order model is assessed against an ideal geometry for additive processes.",,,,,,
"['Tedia, Saish', 'Williams, Christopher B.']",2021-10-26T17:44:32Z,2021-10-26T17:44:32Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89536,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['manufacturability', 'voxel-based', 'geometric modeling', 'part geometry', 'additive manufacturing']",Manufacturability Analysis Tool for Additive Manufacturing Using Voxel-Based Geometric Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d4d3cd71-4b19-4be8-add0-7f1fada8818f/download,University of Texas at Austin,"While Additive Manufacturing (AM) processes provide unparalleled design freedom, they still
impose some constraints on the geometries that can be successfully fabricated. Thus, there exists
a need for predictive analysis of part geometries’ manufacturability. Existing algorithms based on
surface representations require several computationally intensive manipulations. In this paper, the
authors present a framework for performing manufacturability analysis of parts to be manufactured
by AM using a voxel-based representations schema. The input triangular mesh is first converted
into a voxel representation using Ray Casting. Through a series of simple computations on a binary
three-dimensional array, the tool provides feedback on infeasible features, minimum feature size,
support material, orientation and manufacturing time for different build orientations. The tool’s
ability to effectively analyze parts for manufacturability is evaluated against several sample
geometries.",,,,,,
"['Josupeit, Stefan', 'Delfs, Patrick', 'Menge, Dennis', 'Schmid, Hans-Joachim']",2021-11-01T21:07:27Z,2021-11-01T21:07:27Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89752,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['manufacturability', 'lattice structures', 'polymer laser sintering']",Manufacturability and Mechanical Characterization of Laser Sintered Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/05cd0f41-6e54-41f8-bbb8-ed757eadf102/download,University of Texas at Austin,"The implementation of lattice structures into additive manufactured parts is an important
method to decrease part weight maintaining a high specific payload. However, the
manufacturability of lattice structures and mechanical properties for polymer laser sintering are
quite unknown yet. To examine the manufacturability, sandwich structures with different cell
types, cell sizes and lattice bar widths were designed, manufactured and evaluated. A decisive
criterion is for example a sufficient powder removal. In a second step, manufacturable structures
were analyzed using four-point-bending tests. Experimental data is compared to the density of the
lattice structures and allows for a direct comparison of different cell types with varied geometrical
attributes. The results of this work are guidelines for the design and dimensioning of laser sintered
lattice structures.",,,,,,
"['Stephens, Sean', 'Crawford, Richard H.', 'Rogers, William', 'Gitter, Andrew', 'Bosker, Gorden']",2019-09-23T17:27:46Z,2019-09-23T17:27:46Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75984', 'http://dx.doi.org/10.26153/tsw/3083']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prosthesis,Manufacture of Compliant Prosthesis Sockets using Selective Laser Sintering 565,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de3d7aa6-0fd1-4ec1-a6ab-b45a54b30c69/download,,"Solid Freeform Fabrication to date has largely been applied in prototype fabrication or fabrication of patterns for conventional manufacturing methods. However, many opportunities exist for using SFF for manufacturing the actual product. In particular, those applications that require or can be enhanced by custom geometric design seem to be well suited for SFF techniques. In this paper we describe the design of a prosthesis socket for a below-the-knee amputee. This socket is specifically designed to provide compliance in selected areas to enhance the comfort of the wearer. Additionally, the socket contains an integrated pylon fitting that provides a structurally superior connection while also improving the comfort of the wearer. The socket was manufactured using selective laser sintering, mated to a pylon and foot, and fitted to the patient for gait analysis. The results of the analysis indicate an improved fit is possible with manufacture by SLS.",The authors acknowledge the support of the Veterans Administration for partial support of this work.,,,,,
"['Suryakumar, S.', 'Somashekara, A.']",2021-10-12T18:25:56Z,2021-10-12T18:25:56Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88714', 'http://dx.doi.org/10.26153/tsw/15648']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['weld-deposition based additive manufacturing', 'additive manufacturing', 'twin-wire', 'process parameters', 'mechanical properties', 'material properties']",Manufacture of Functionally Gradient Materials using Weld-Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/264d0f6a-b4ce-4ef9-8b8f-7be1a00c2bf8/download,University of Texas at Austin,"When the inherent inhomogeneity of Additive Manufacturing techniques is carefully
exploited, the anisotropy transforms into the desired distribution of the properties paving the way
for manufacture of Functionally Gradient Materials. The present work focuses on using weld-deposition based Additive Manufacturing techniques to realize the same. Mechanical properties
like hardness and tensile strength can be controlled by a smaller degree through control of
process parameters like current, layer thickness etc. A wider control of material properties can be
obtained with the help of tandem weld-deposition setup like twin-wire. In tandem twin-wire
weld-deposition, two filler wires (electrodes) are guided separately and it is possible to control
each filler wire separately. The investigations done on these two approaches are presented in
paper.",,,,,,
"['Badrinarayan, B.', 'Barlow, J.W.']",2018-10-03T18:28:01Z,2018-10-03T18:28:01Z,1994,Mechanical Engineering,doi:10.15781/T2P844F4Z,http://hdl.handle.net/2152/68672,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SLS technology', 'CAD', 'rapid prototyping']",Manufacture Of Injection Molds Using SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/28a4a235-8ce6-4c93-af80-cfd62918d6fb/download,,"This paper describes the use of SLS technology for the fabrication of injection mold
cavities. Green shapes were made from metal - copolymer powder mixtures by SLS. The
copolymer was gradually burnt out and the metal was oxidized in an air furnace. The porous
oxidized metal part was subsequently infiltrated with an epoxy resin and cured. Effect of process
variables in SLS, effect of oxidation cycle, dimensional changes on oxidation and epoxy
infiltration of the oxidized metal part are discussed.",,,,,,
"['Dechet, Maximilian A.', 'Lanzl, Lydia', 'Werner, Yannick', 'Drummer, Dietmar', 'Bück, Andreas', 'Peukert, Wolfgang', 'Schmidt, Jochen']",2021-11-18T16:30:33Z,2021-11-18T16:30:33Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90417', 'http://dx.doi.org/10.26153/tsw/17338']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['glass fiber composite particles', 'polyamide 11', 'PA11', 'selective laser sintering']",Manufacturing and Application of PA11-Glass Fiber Composite Particles for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a9d4a4e-c410-4cb1-9c10-3e0b298df22f/download,University of Texas at Austin,"Selective laser sintering (SLS), a powder-based additive manufacturing technology, employs micronsized polymer particles, which are selectively fused by a laser. SLS yields excellent part qualities with good
mechanical properties. However, a persistent challenge in this layer-by-layer process is a reduction of
mechanical properties in the z-direction. This is often caused by insufficient layer adhesion. One way to
strengthen the layer adhesion in z-direction is the incorporation of glass fibers, which exceed from one
layer into another. However, most commercially available glass-fiber enhanced materials are dry blends
of the polymer powders and the fibers. In order to enhance the isotropic mechanical properties of parts
manufactured via selective laser sintering, the manufacturing of glass fiber-filled PA11 particles is shown in
this contribution. We present a single-pot approach to produce glass fiber-filled polyamide 11 (PA11)
composite particles. The particles are manufactured via liquid-liquid phase separation and precipitation [1]
(also known as solution-dissolution process) from ethanol glass fiber dispersions. Bulk polymer material of
PA11 is directly converted to composite microparticles in a single process. The produced particles are
characterized regarding their size and morphology. The amount of glass fibers in the bulk is assessed via
thermogravimetric analysis and the effect of the fibers on the processing window is investigated via
differential scanning calorimetry (DSC). As a proof of concept, the powder is employed in the SLS process to
produce glass fiber-enhanced test specimens for mechanical testing.",,,,,,
"Sachs, Emanuel",2019-10-18T17:11:15Z,2019-10-18T17:11:15Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76266', 'http://dx.doi.org/10.26153/tsw/3355']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Manufacturing by Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a149ee04-5569-4fe0-acdc-4e9bc9403af1/download,,"The SFF/RP industry has grown steadily with the most significant gains made in the number
of models produced per year – three million in the year 2000. Future growth is most likely to be
in manufacturing applications of SFF where even a single application can double the number of
models/parts produced annually. There are a number of factors or drivers which can motivate a
manufacturing application of SFF either individually or in combination. These drivers include:
i. avoid conventional tooling, ii. minimizing hand work, iii. mass customization, iv. geometric
flexibility, v. local control of composition. The most intriguing of these drivers is that of mass
customization – the manufacture of highly individual products, but on a mass scale. SFF offers
the possibility of mass customization of components with complex 3D geometry. A prominent
current example is that of Align Technology of Santa Clara, CA which produces unique plastic
aligners for orthodontic applications.
There already are manufacturing applications where the advantages offered by SFF are so
compelling as to overcome any barriers. However, widespread impact of SFF on manufacturing
will depend on overcoming several barriers. The essence of these barriers lies in the distinction
between prototyping and manufacturing. Manufacturing applications are far more demanding in
terms of build rate and associated cost, demands on dimensional control and tolerances,
properties of materials, and ease of use and serviceability of equipment.",,,,,,
"['Kerbrat, O.', 'Mognol, P.', 'Hascoet, J.-Y.']",2021-09-23T22:29:50Z,2021-09-23T22:29:50Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88039', 'http://dx.doi.org/10.26153/tsw/14980']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['subtractive processes', 'additive processes', 'hybrid modular tooling']",Manufacturing Complexity Evaluation For Additive and Subtractive Processes: Application to Hybrid Modular Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e7f856b7-75c1-4662-8992-8849d7ca077c/download,,"The aim of this work is to determine how to combine a subtractive process (HSM) and an
additive process (SLS) to realize tools (dies or molds). In fact, the design and manufacturing
of tools may be optimized with hybrid and modular points of view. Tools are not seen as
single pieces but as 3-D puzzles with modules; each module is manufactured by the best
process. So a new methodology is proposed: the most complex-to-manufacture areas of a tool
are determined (based on a manufacturability analysis from tool CAD model) and a hybrid
modular tool CAD model with a reduced manufacturing complexity is proposed.",,,,,,
"['Beck, James E.', 'Prinz, Fritz B.', 'Siewiorek, Daniel P.', 'Weiss, Lee E.']",2018-04-19T18:32:33Z,2018-04-19T18:32:33Z,1992,Mechanical Engineering,doi:10.15781/T23N20X5T,http://hdl.handle.net/2152/64408,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Mechatronics', 'Thermal Spray', 'shape deposition']",Manufacturing Mechatronics Using Thermal Spray Shape Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fcd14e93-6df5-4214-8aec-6bd9a4c7ea62/download,,"A new technology for manufacturing mechatronics is described. The technique is based on recursive
masking and deposition of thermally sprayed materials. Using these methods, mechanical structures
can be created that embed and interconnect electronic components. This results in highly integrated
mechatronic devices. A simple, electromechanical artifact was designed and produced to assess the
feasibility of these techniques. The details and limitations of this project will be discussed. Areas of
future research are identified which are aimed at realizing the full potential of this emerging manufacturing
process.",,,,,,
"['Williams, Christopher B.', 'Rosen, David W.']",2020-03-10T16:23:58Z,2020-03-10T16:23:58Z,9/5/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80224', 'http://dx.doi.org/10.26153/tsw/7243']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Additive Manufacturing,Manufacturing Metallic Parts with Designed Mesostructure via Three-Dimensional Printing of Metal Oxide Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb783689-9258-4328-91f8-102dc2509844/download,,"Cellular materials, metallic bodies with gaseous voids, are a promising class of materials that offer
high strength accompanied by a relatively low mass. In this paper, the authors investigate the use of ThreeDimensional Printing (3DP) to manufacture metallic cellular materials by selectively printing binder into a
bed of metal oxide ceramic powder. The resulting green part undergoes a thermal chemical post-process in
order to convert it to metal. As a result of their investigation, the authors are able to create cellular
materials made of maraging steel that feature wall sizes as small as 400 µm and angled trusses and channels
that are 1 mm in diameter.",,,,,,
"['Morvan, Stephane', 'Fadel, Georges', 'Love, James', 'Keicher, Dave']",2019-10-18T16:59:04Z,2019-10-18T16:59:04Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76261', 'http://dx.doi.org/10.26153/tsw/3350']",eng,2001 International Solid Freeform Fabrication Symposium,Open,LENS Apparatus,Manufacturing of a Heterogeneous Flywheel on a LENS Apparatus,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d07107e-c7a9-4d2b-a34f-f10d2d0e4c63/download,,"The design of a 1D gradient component satisfying a particular set of constraints is extended to its
manufacturing on a multi-material capable apparatus. The geometry and composition of this flywheel were
designed to meet a bi-objective optimum featuring maximum kinetic energy storage and minimal maximum
von-Mises stress along its radius. The efforts expanded during the transformation of this design from a
computer abstraction into a tangible object are presented. The process-planning step of the manufacturing
of this heterogeneous solid, which was dependent on the specifics of a LENS-based Apparatus, required a
different approach than that of traditional solids, and proved critical during fabrication.",,,,,,
"['Hascoet, J.Y.', 'Muller, P.', 'Mognol, P.']",2021-10-05T14:26:55Z,2021-10-05T14:26:55Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88378', 'http://dx.doi.org/10.26153/tsw/15317']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['functionally graded materials', 'morphologically complex parts', 'bi-materials gradients', 'additive manufacturing']",Manufacturing of Complex Parts with Continuous Functionally Graded Materials (FGM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/3db9799c-fa1e-4081-9a67-107390b7b5a4/download,University of Texas at Austin,"One of major evolutions of the additive manufacturing is the ability to produce parts with
functionally graded materials (FGM). However, manufacturing of these parts is limited to
discrete or nearly continuous FGM on samples. To achieve this, it is necessary to have a global
control of processes and to develop methodologies to help designers and manufacturers. A
methodology to produce morphologically complex parts is proposed in this paper. It consists in
classifying all typologies of bi-materials gradients with mathematical description. Each typology
of gradient is associating with manufacturing strategies in order to choose slicing and path
strategies. Afterwards, mathematical data are used to have a global control of a process. This
paper presents the principle of this methodology and the mathematical models which are chosen
to describe part and manufacturing.",,,,,,
"['Shimek, Moss', 'Patwardhan, Nachiket', 'Wood, Kristin L.', 'Beaman, Joseph', 'Crawford, Richard']",2019-10-18T15:23:32Z,2019-10-18T15:23:32Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76237', 'http://dx.doi.org/10.26153/tsw/3326']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Instrumented,Manufacturing of Instrumented Prototypes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15e2a308-2bf5-41f8-85c0-e51c7b2a2174/download,,"The research for the Cybernetic Physical project at UT Austin has the goal of
producing instrumented prototypes, using selective laser sintering (SLS) that can be used
in concert with similarity methods to update virtual models. The SLS process builds
prototypes sintering powder in a 2-D cross-section, layer by layer, with a CO2 laser.
Accomplishing this goal could significantly reduce cycle times and costs associated with
traditional prototyping methods. Strain gages and thermocouples are chosen as the first
sensors to be embedded. Experiments have been carried out to determine the feasibility
of embedding sensors both after the manufacturing process as well as during the SLS
process. These experiments have yielded data that will serve as a set of design
requirements for the embedding process. The results from the post-embedded prototypes
closely matched the theoretical results in one case. Hence a design of experiments will be
carried out to study the effects of various factors on these sensors. Embedding
thermocouples during an SLS build cycle uncovered issues that must be addressed in the
design process, such as keeping the sensor and lead wires flat on the cross-section and
managing the extra lead wires. A 1-D heat source, pin fin model was used to accurately
predict the temperature reading of the thermo couple in the sample. The error was
approximately 3.3%.",,,,,,
"['Dechet, Maximilian A.', 'Lanzl, Lydia', 'Wilden, Alisa', 'Sattes, Maria-Melanie', 'Drummer, Dietmar', 'Peukert, Wolfgang', 'Schmidt, Jochen']",2021-11-18T16:33:11Z,2021-11-18T16:33:11Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90418', 'http://dx.doi.org/10.26153/tsw/17339']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['nanoparticle-filled composite particles', 'polyamide 11', 'PA11', 'selective laser sintering']",Manufacturing of Nanoparticle-Filled PA11 Composite Particles for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/714236bb-21ea-4f24-95d7-7c7deb6e8e11/download,University of Texas at Austin,"Selective laser sintering (SLS) is an Additive Manufacturing (AM) process that yields excellent part
qualities with good mechanical properties. The SLS process employs micron-sized polymer particles, which are
selectively fused by a laser. While there seem to be hardly any boundaries regarding design, there are quite
some restrictions concerning the variety of commercially available SLS materials. With a market share of
roughly 90%, polyamide 12 (PA12) is currently the most widely used polymer material for SLS. Concerning
particle or fiber enhanced materials, only dry blended, but hardly any composite materials are available.
In this contribution, the manufacturing of nanoparticulate alumina-, titania- and silica-filled polyamide 11
(PA11) particles is demonstrated. The particles are manufactured via liquid-liquid phase separation and
precipitation (also known as solution-dissolution process) from ethanol dispersions. Bulk polymer material of
PA11 is directly converted to composite microparticles in a one-pot approach. The produced particles are
characterized regarding their size and morphology. The amount of nanoparticles in the bulk is assessed via
thermogravimetric analysis (TGA). Furthermore, the effect of the nanoparticles as nucleating agents is
investigated via DSC and correlated with surface energies as determined by inverse gas chromatography (IGC).",,,,,,
"['Ruvalcaba, Bryan E.', 'Arrieta, Edel', 'Escarcega, Andres H.', 'Medina, Francisco', 'Wicker, Ryan B.']",2021-11-30T20:04:05Z,2021-11-30T20:04:05Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90530', 'http://dx.doi.org/10.26153/tsw/17449']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'manufacturing process', 'parameter development', 'water-atomized zinc powder']",Manufacturing Process and Parameters Development for Water-atomized Zinc Powder for Selective Laser Melting Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bafaca19-44c1-4376-99eb-022738b74614/download,University of Texas at Austin,"Biodegradability of metals is a desirable characteristic for medical implants. Metals like
Fe, Mg, Zn and their alloys are usually preferred for this application, as their degradation rate has
been shown to work on medical implants. The fast degradation rate of Mg may early
compromise its structural performance for these components; while the slower degradation rate
of Fe may also become a disadvantage. This leaves Zinc’s degradation rate more suitable for this
application. Vaporization temperatures make zinc a challenging material to use in conventional
additive manufacturing systems. In this work, the process of developing parameters to print
water atomized zinc powder is presented. This process was performed in a commercial SLM
system, implying inconveniences for a powder not optimized for AM. Optical analysis of wateratomized powder was conducted for size and shapes measurement of precursor powder. This
work includes density and microstructure analysis, followed up by conclusion and remarks.",,,,,,
"['Lambert, Philip', 'Chartrain, Nicholas', 'Schultz, Alison', 'Cooke, Shelley', 'Long, Timothy', 'Whittington, Abby', 'Williams, Christopher']",2021-10-18T20:49:00Z,2021-10-18T20:49:00Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89241,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Mask Projection Microstereolithograhy', 'biocompatible polymers', 'biocompatibility']",Mask Projection Microstereolithography of Novel Biocompatible Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5506e78f-519a-42e2-8937-92353ead999c/download,University of Texas at Austin,"Mask Projection Microstereolithography (MPμSL) selectively cures entire layers of
photopolymer to create three-dimensional parts with features on the micron scale. The resolution
and scale of MPμSL are ideal for fabricating tissue engineering scaffolds with designed
mesostructure. While MPμSL have excellent resolution, there are few biocompatible materials
that are compatible with the vat photopolymerization processes. A novel diacrylate
functionalized Pluronic L-31 block-copolymer and poly(propylene glycol diacrylate) were
synthesized and processed with MPμSL. The resulting structures were analyzed for
biocompatibility, as well as accuracy and mechanical strength to assess feasibility for use in
tissue engineering scaffold fabrication. Preliminary fabricated scaffold geometries are presented
to validate experimental results.",,,,,,
"['Pallari, J. H. P.', 'Dalgarno, K. W.', 'Woodburn, J.']",2020-02-27T20:39:32Z,2020-02-27T20:39:32Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80103', 'http://dx.doi.org/10.26153/tsw/7124']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Rheumatoid arthritis,Mass Customization of Foot Orthosis for Rheumatoid Arthritis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2dac7d96-b85a-4530-b9be-e1881b8b99e8/download,,"Rheumatoid arthritis (RA) is an inflammatory disease, which can cause pain, stiffness, and
swelling in the joints of hands and feet. The foot is a major site for RA involvement and a
major source of disability resulting from this disease. This paper introduces research which
aims to create a mass customisation process for customised orthoses for patients with RA.
3D laser scanning, and gait analysis will be used to generate the orthosis geometry and
rapid manufacturing, namely the selective laser sintering (SLS) process, will be used to
produce the orthoses. The SLS process enables the incorporation of compositional
functional elements, such as locally adjusted stiffness or flexibility, into the orthosis
design.
The process involved two central elements. The first was a literature survey to identify
orthotic design rules for foot impairments in RA. This survey will form a platform for the
design rule development and will be complemented by data obtained from two patient
trials. The second is a virtual three-segment foot model, created in Anybody dynamics
modelling software which can be motivated by data measured from patients using 3D
motion capture and force plate systems. Once the measured data has been applied to the
model, a virtual insole can be used to simulate the effects of various features in the
orthosis.
Considerable variation was noted in the literature for types of material, design and
methods of orthotic construction. Pressure redistribution using cushioning materials was
consistently mapped to painful deformed joints. Orthoses with contoured surfaces, either
custom- or mass produced in thermoplastic materials of varying stiffness and density were
mapped to joint motion control and deformity prevention. The paper will also describe
applying patient gait data to the Anybody model, and then altering the gait pattern by
applying the insole model. Future work will also be discussed.",,,,,,
"['Ye, Hang', 'Zhou, Chi', 'Xu, Wenyao']",2021-10-26T17:53:21Z,2021-10-26T17:53:21Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89539,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['mass customization', 'additive manufacturing', 'topology', 'slicing', 'CLIP']",Mass Customization: Reuse of Topology Information to Accelerate Slicing Process for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7e4256f4-aeef-4bbf-8795-7e1dcf5b1b50/download,University of Texas at Austin,"Additive manufacturing (AM) can build objects with complex features with little extra
effort, opening up potentials to realize mass customization. Continuous Liquid Interface
Production (CLIP) prints object in a continuous fashion, leading to extremely high productivity
and consequently enabling mass customization. CLIP adopts a large number of images as input,
which poses a fundamental challenge in layer generation. The slicing procedure for a single
customized model can take tens of minutes or even hours to complete, and the time consumption
becomes more prominent in mass customization context. Motivated by the similarities among the
customized products, we proposed a new slicing paradigm. It reuses topology information
obtained from the template model for other customized products from the same category. The
idea of topology information reuse is implemented at three levels, including self reuse, intra-model reuse, and inter-model reuse. Experimental results show that the proposed slicing
paradigm can significantly reduce the time consumption on pre-fabrication computation, and
ultimately fulfill mass customization enabled by AM.",,,,,,
"['Delfs, P.', 'Li, Z.', 'Schmid, H.-J.']",2021-10-20T20:30:07Z,2021-10-20T20:30:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89355,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'mass finishing', 'disc finishing']",Mass Finishing of Laser Sintered Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cf5566ee-2122-4282-8378-b1692567b564/download,University of Texas at Austin,"Selective laser sintered (SLS) part surfaces are quite rough textured by the
layered structure and adherence of incomplete molten powder particles. Different
post-treatments can help to smooth these surfaces. In this work we investigated
the mass finishing method with a disc finishing machine. The aim was to quantify
the influences of different process parameters on roughness values and rounding of
edges. Therefore different geometries and material of abrasive media were used.
Further the intensity was varied by changing the rotational speed and duration
of the finishing process. Analysis was done with a 3D optical microscope to get
profile and areal roughness parameters as well as radii of edges. SLS part surfaces
with build angles from 0°
to 180°
in 15°
steps were evaluated. The results show
that depending on the used abrasive media roughness values can be reduced to
about 15 % of its initial value in a few hours of finishing.",,,,,,
"['Chartoff, Richard P.', 'Flach, Lawrance', 'Weissman, Peter']",2018-05-03T19:26:47Z,2018-05-03T19:26:47Z,1993,Mechanical Engineering,doi:10.15781/T2J679D77,http://hdl.handle.net/2152/65064,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['SLA', 'rapid prototyping', 'stereolithography']",Material and Process Parameters that Affect Accuracy in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4f26f401-e99d-4e70-903a-f9bd1f6124fe/download,,"Experimental real time linear shrinkage rate measurements simulating stereolithography
are used in an analysis of shrinkage during line drawing in stereolithography. While the amount of
shrinkage depends on the polymerization kinetics, shrinkage kinetics and overall degree of cure, it
also depends on the length of time to draw a line of plastic. A line drawn slowly will exhibit less
apparent shrinkage than one drawn very quickly because much of the shrinkage is compensated
for as the line is drawn. The data also indicates that a typical stereolithography resin in the green
state may shrink to only 65% of its maximum, thus retaining considerable potential for shrinkage
during post-cure. This infonnation can be used to predict the amount of shrinkage to be expected
under certain exposure conditions and to fonnulate overall strategies to reduce shrinkage and
subsequent warpage that causes shape distortion.",,,,,,
"['Dobson, Sean', 'Wu, Yan', 'Yang, Li']",2021-11-09T18:39:54Z,2021-11-09T18:39:54Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90113', 'http://dx.doi.org/10.26153/tsw/17034']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['thin wall structures', 'lightweight structures', 'material characteristics', 'Ti-6Al-4V', 'EOS M270', 'laser melting powder bed fusion', 'LM-PBF', 'additive manufacturing']",Material Characterization for Lightweight Thin Wall Structures Using Laser Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d25a63f6-7047-4887-844e-a3e541f5d53e/download,,"In this study the geometry-process-material characteristics of the Ti6Al4V thin wall features
fabricated by the EOS M270 laser melting powder bed fusion (LM-PBF) additive manufacturing
(AM) was investigated. Samples with varying wall thickness, orientation, scanning speeds and
laser power were fabricated and analyzed. The dimensional accuracies, microstructural
characteristics and mechanical properties of the samples were evaluated experimentally. The
results clearly indicated the significant coupling effects between the geometry design of these thin
wall features and their material properties, which is critical to the design and manufacturing of
many AM lightweight structures. By identifying significant design and process parameters for the
thin wall structures, this study will enable further investigations of the integrated design theories
for the AM lightweight structures.",,,,,,
"['Nodehi, Mehrab', 'Asiabanpour, Bahram', 'Omer, Liam', 'Ozbakkaloglu, Togay']",2021-12-07T18:24:10Z,2021-12-07T18:24:10Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90748', 'http://dx.doi.org/10.26153/tsw/17667']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D printing cementitious materials', '3D concrete printing']",Material Characterization of Diversity Aggregated Cementitious Materials Produced with a Modular Lightweight Additive Manufacturing Extrusion System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c46be270-e943-4d38-b6b0-19ab0ec52f18/download,University of Texas at Austin,"Applications of additive manufacturing in the construction industry started three decades ago with the first patent and prototype of the contour crafting process. Since then, its obvious benefits in reducing labor cost, construction waste while improving efficiency and flexibility have led to the development of several large-scale commercial machines in this field. However, proper lab-scale machines for training experts in automated construction and research-based activities such as material optimizations for civil and structural engineers are not available. The only available small-scale apparatus in AM-based construction is limited to a minimal list of materials and properties. Those machines are not capable of fabricating samples from cementitious materials with a variety of aggregate sizes. This paper compares two low-cost, modular AM-based construction systems capable of extruding a wide variety of cementitious materials with diverse aggregate sizes. The systems are capable of controlled extrusion with a variety of cross-section forms. The system can be attached to a robotic arm, CNC machine, or other programmable machines. As a proof-of-concept, the developed system is utilized to fabricate cement mortar with larger aggregate sizes with different materials mixture ratios. Mechanical performance of the resulting additively manufactured cementitious parts is examined and compared.",,,,,,
"['Amon, Christina', 'Beuth, Jack', 'Kirchner, Helmut', 'Merz, Robert', 'Prinz, Fritz', 'Schmaltz, Kevin', 'Weiss, Lee']",2018-05-03T16:20:53Z,2018-05-03T16:20:53Z,1993,Mechanical Engineering,doi:10.15781/T2P26QM6W,http://hdl.handle.net/2152/65032,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['layered manufacturing', 'sintering', 'melting', 'thermal modeling', 'residual stress', 'multi material', 'structures', 'stress cracking']",Material Issues in Layered Forming,Conference paper,https://repositories.lib.utexas.edu//bitstreams/047d947b-98c6-4729-9a86-8996a5afcca4/download,,"A brief overview of key issues in layered thermal processing is given. Incremental sintering
and layered fusion ofpowder and molten droplets are discussed. The criteria for remelting the solid
substrate are derivedfrom a one dimensional heat transfer model. Temperature gradients which
occur during solidification and subsequent cooling. are responsible for the build up of internal
stresses which can be estimated through establishing an elastic beam model. The difficulties as well
as opportunities regarding the generation of multi-layer multi-material structures are also described
in this article.",,,,,,
"['Boivie, K.', 'Karlsen, R.', 'Van der Eijk, C.']",2020-02-28T15:07:59Z,2020-02-28T15:07:59Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80109', 'http://dx.doi.org/10.26153/tsw/7130']",eng,2006 International Solid Freeform Fabrication Symposium,Open,metal printing process,"Material Issues of the Metal Printing Process, MPP",Conference paper,https://repositories.lib.utexas.edu//bitstreams/214a2d4c-d87b-4409-a13c-91b058767bc3/download,,"The metal printing process, MPP; is a novel Rapid Manufacturing process under development
at SINTEF and NTNU in Trondheim, Norway. The process, which aims at the manufacturing
of end-use products for demanding applications in metallic and CerMet materials, consists of
two separate parts; The layer fabrication, based on electrostatic attraction of powder materials,
and the consolidation, consisting of the compression and sintering of each layer in a heated
die. This approach leads to a number of issues regarding the interaction between the process
solutions and the materials. This paper addresses some of the most critical material issues at
the current development stage of MPP, and the present solutions to these.",,,,,,
"Lipton, Jeffrey I.",2024-03-27T15:48:34Z,2024-03-27T15:48:34Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124490', 'https://doi.org/10.26153/tsw/51098']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['material jetting', 'suspension system', 'additive manufacturing']",Material Jetting of Suspension System Components.,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e93401fe-b03a-4b49-93cf-511b19742ce8/download,University of Texas at Austin,"Material Jetting has demonstrated great promise in being able to produce complex
functionalities using multi-material printing. Despite this potential material jetting has struggled
to find applications in direct part production. Here we show how material jetting can be used to
produce viscoelastic energy absorbers for large displacement applications in harsh environments.
We generate printed components to act as the core of a suspension system on a recumbent trike.
The 3D printed dampers allowed for improvements of the ride experienced. Through long term
exposure studies, we demonstrate that techniques and methods previously applied to the absorption
of vibration in indoor power tool applications can be extended to outdoor environments.",,,,,,
"['Sekmen, K.', 'Rehbein, T.', 'Johlitz, M.', 'Lion, A.', 'Constantinescu, A.']",2023-03-29T16:20:25Z,2023-03-29T16:20:25Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117677', 'http://dx.doi.org/10.26153/tsw/44556']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'UV curing', 'photopolymer', 'reaction kinetics', 'viscoelastic modelling']",Material Modelling of the Photopolymers for Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8103589b-ef51-4986-aca5-aa5579c2ae11/download,,"Ultraviolet (UV) curing of polymers is a key phenomenon for several additive 
manufacturing technologies. This contribution presents a model relating the process parameters of 
UV light intensity and temperature to the thermal and mechanical properties of the polymer and 
the experimental results used to calibrate the model. Moreover, photo-differential scanning 
calorimetry (photo-DSC) measurements are performed to investigate the crosslinking reaction and 
to model the degree of cure as a function of the light intensity and temperature. The viscoelastic 
properties are measured by UV rheometry and it is shown that the classical time-cure superposition 
principle can equally be applied to the experimental results. Complete curing and mechanical 
model equations are provided to describe the material behavior as a result of our experimental 
findings.",,,,,,
"['Guo, C.', 'Ge, W.J.', 'Lin, F.']",2021-10-18T21:39:13Z,2021-10-18T21:39:13Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89256,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Selective Melting', 'material molten time', 'material deposition']",Material Molten Time and its Effect on Material Deposition during Electron Beam Selective Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97239d58-f96a-4a58-b7ef-5677d66f45dd/download,University of Texas at Austin,"Electron Beam Selective Melting (EBSM) is an additive manufacturing technology
that directly fabricates parts from metal powders in a layer-by-layer fashion. The material
molten time, which equals the total time that material keeps molten during scanning, is
selected as an indicator for evaluating the effects of process parameters on material deposition.
A finite elements model was established to simulate the molten time distribution within the
scanning area for various parameters. Samples were fabricated using the same parameters in
simulation. It’s found that there is a strong relation between the molten time and material
deposition behavior. Appropriate material molten time results in a dense and flat surface. Too
little material molten time leads to a non-dense surface and internal pores, and too much
material molten time leads to a distorted surface and coarsened microstructures. The material
molten time increases with the increase of beam current and with the decrease of scanning
velocity and length of scanning line. An optimized process which aims to obtain appropriate
and homogeneous molten time within the scanning area is also developed to improve the
deposition quality.",,,,,,
"['Fan, K.M.', 'Cheung, W.L.', 'Gibson, L.']",2019-10-09T16:29:46Z,2019-10-09T16:29:46Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76158', 'http://dx.doi.org/10.26153/tsw/3247']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Trueform,Material Movement and Fusion Behavior of TrueForm and TrueForm/SiO2 during Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0d20892-823c-4460-8e49-78aee023a779/download,,"Different material systems, TrueForm and TrueForm/SiO2 composites, were sintered under
similar conditions. A microscope equipped with a CCD camera was utilized to examine the
material movement near the laser beam. Powder movement of the blends was found to start at
different ranges ahead of the line of scan. For TrueForm, the polymer particles were found to
undergo fusion ahead of the laser beam and form a band, 0.5-0.7mm wide, which then moved as
a single block towards the sintered area. The dry mixed TrueForm/SiO2 composites (dry blends)
exhibited a short-range material movement in the form of small agglomerates. Meanwhile, the
TrueForm/SiO2 composite powder prepared by melt extrusion (melt blend) showed a range of
material movement between those of TrueForm and the dry blends. The discrepancy is believed
to arise from changes in heat transfer properties and fusion behavior after blending. The surface
temperature of the powder bed was monitored during sintering. Generally, the dry blends
exhibited a higher surface temperature. Apparently, both the particle size of SiO2 and the
blending method had an effect on the temperature and material movement, and hence on the final
morphology of the sintered components.",,,,,,
"['Raju, Nandhini', 'Warren, Peter', 'Subramanian, Ramesh', 'Ghosh, Ranajay', 'Raghavan, Seetha', 'Fernandez, Erik', 'Kapat, Jayanta']",2021-12-06T22:12:19Z,2021-12-06T22:12:19Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90693', 'http://dx.doi.org/10.26153/tsw/17612']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['17-4 PH stainless steel', 'material properties', 'atomic diffusion additive manufacturing', 'ADAM']",Material Properties of 17-4PH Stainless Steel Fabricated by Atomic Diffusion Additive Manufacturing (ADAM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/4d15f0d0-baeb-4b10-b1c9-b0ea47a808ce/download,University of Texas at Austin,"The objective of this paper is to investigate the material properties of 17-4PH stainless steel printed by the
Atomic Diffusion Additive manufacturing technique. Samples with film cooling holes in different orientations
were manufactured in a Markforged Metal-X machine. The presence of the holes in these samples helps to
understand the printability and accuracy of internal cooling holes, as manufactured by the Metal-X machine.
Manufactured samples were first washed to remove the plastic binder. These pre-sintered samples were tested,
before sintering, for density, microstructure analysis, CT (Computerized Tomography) scan, roughness, and XRF
(X-ray Fluorescence Spectrometer) to understand the material properties. The printed holes, their anomalies, and
selection of standards of testing will be discussed along with the material behavior of 17-4PH stainless steel.",,,,,,
"['Maines, Erin', 'Bell, Nelson', 'Evans, Lindsey', 'Roach, Matthew', 'Tsui, Lok-kum', 'Lavin, Judith', 'Keicher, David']",2021-11-10T21:11:30Z,2021-11-10T21:11:30Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90176', 'http://dx.doi.org/10.26153/tsw/17097']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['low viscosity resin', 'ceramic slurries', 'material properties', 'stereolithography', 'additive manufacturing']",Material Properties of Ceramic Slurries for Applications in Additive Manufacturing Using Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/18c401e4-9f99-40ec-bfa5-2d742f4e3383/download,University of Texas at Austin,"Stereolithography (SL) is a process that uses photosensitive polymer solutions to create
3D parts in a layer by layer approach. Sandia National Labs is interested in using SL for the
printing of ceramic loaded resins, namely alumina, that we are formulating here at the labs. One
of the most important aspects for SL printing of ceramics is the properties of the slurry itself. The
work presented here will focus on the use of a novel commercially available low viscosity resin
provided by Colorado Photopolymer Solutions, CPS 2030, and a Hypermer KD1 dispersant from
Croda. Two types of a commercially available alumina powder, Almatis A16 SG and Almatis
A15 SG, are compared to determine the effects that the size and the distribution of the powder
have on the loading of the solution using rheology. The choice of a low viscosity resin allows for
a high particle loading, which is necessary for the printing of high density parts using a
commercial SL printer. The Krieger-Dougherty equation was used to evaluate the maximum
particle loading for the system. This study found that a bimodal distribution of micron sized
powder (A15 SG) reduced the shear thickening effects caused by hydroclusters, and allows for
the highest alumina powder loading. A final sintered density of 90% of the theoretical density of
alumina was achieved based on the optimized formulation and printing conditions.",,,,,,
"['Josupeit, Stefan', 'Lohn, Johannes', 'Hermann, Eduard', 'Gessler, Monika', 'Tenbrink, Stephan', 'Schmid, Hans-Joachim']",2021-10-20T20:44:57Z,2021-10-20T20:44:57Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89357,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'build cycles', 'refresh cycles', 'refresh rates', 'polyamide 12']",Material Properties of Laser Sintered Polyamide 12 as Function of Build Cycles Using Low Refresh Rates,Conference paper,https://repositories.lib.utexas.edu//bitstreams/74a9b460-ce44-41da-9503-e5dcfd688ff5/download,University of Texas at Austin,"Due to long process times at high temperatures, unmolten polyamide 12 material ages
during the manufacturing process. Hence, it needs to be refreshed with new material for further
build cycles. In application, refresh rates of about 50 % are commonly used. In this work, the
recycling optimized material PA 2221 from EOS is analyzed along a series of 13 build and refresh
cycles using a reduced refresh rate of 32 %. Before and after every build, the powder is analyzed
regarding melt properties determined by MVR and DSC measurements. Thereby, in-process ageing
effects are investigated and the steady-state conditions are determined accordingly. In addition,
powder properties are directly linked to resulting mechanical and geometrical part properties. Key
findings are a robust DSC measurement method for polyamide 12 powder, constant “circulated”
material properties after three build/refresh cycles and robust tensile properties along the whole
tested powder life cycle. As a result, process conditions of PA 2221 using reduced refresh rates can
be derived from this work.",,,,,,
"['Kaweesa, Dorcas V.', 'Meisel, Nicholas A.']",2021-11-11T15:40:50Z,2021-11-11T15:40:50Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90224', 'http://dx.doi.org/10.26153/tsw/17145']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['digital composite structures', 'voxel size', 'custom design', 'material property', 'functionally graded materials', 'FGMs', 'additive manufacturing']",Material Property Changes in Custom-Designed Digital Composite Structures Due to Voxel Size,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cfc5bf92-265a-4654-b476-f9342718924a/download,University of Texas at Austin,"Advances in additive manufacturing enable fabrication of complex structures using functionally
graded materials (FGMs) at a voxel level. Prior to developing voxel-based FGM designs using
compatible dithering approaches, it is essential to first understand the basic principles of voxel-based digital composite designs. While several research studies exist regarding different
representations of composition in voxel-based solid models, there is no extensive research on the
material properties of voxel-based digital composite structures. This paper bridges this gap by
investigating custom voxel-based designs of digital composite structures. The objective is to
determine how the material properties of such structures are impacted by different voxel sizes
using the material jetting process. In addition to the material properties, computational time taken
to process different voxel sizes is analyzed. By doing so, we gain a better understanding of the
relationship between material composition and voxel size in digital composite structures.",,,,,,
"['Dinda, Shantanab', 'Banerjee, Dishary', 'Shaffer, Derek', 'Ozbolat, Ibrahim T.', 'Simpson, Timothy W.']",2023-02-09T19:01:35Z,2023-02-09T19:01:35Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117442', 'http://dx.doi.org/10.26153/tsw/44323']",eng,2022 International Solid Freeform Fabrication Symposium,Open,metal implants,Material Selection & Design for Lattice-Based Biodegradable Metal Implants for Bone Regeneration in  Load-Bearing Bone Defects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a62d2168-e877-4706-9a0f-d0409cc5ff01/download,,"Human bone is a dynamic tissue and has a natural ability to repair small fractures quickly; however, critical 
fractures below the waist require external mechanical aids to help bear loading while healing.  These techniques 
are effective but tend to cause a lack of mobility and decrease quality of life. New materials focused on the 
biodegradability of implants have opened new avenues in implant design and fabrication, reducing previous 
concerns such as tunability of degradation rates in such materials.  Furthermore, three-dimensional (3D) printed 
biodegradable metallic implants show promise as an alternative for expediting recovery and increasing mobility, 
especially with the growth of lattice-based design and better osseointegration techniques.  This study discusses 
the development and testing of a functional AM implant that integrates load-bearing, biodegradability, 
biocompatibility, and osseointegration, with an eye toward clinical translation.  Based on the desired material 
properties, an iron-manganese mixture is used, along with dopants to aid biocompatibility and improve 
degradation rates. Lattice-based design has been implemented to reduce material usage without affecting 
mechanical properties, and the implants have been printed using binder jetting.  After fabrication, experiment 
analysis to evaluate mechanical properties, degradation rates and byproducts, in-vitro performance, and 
microstructure has been performed for validation, to prepare the implant for in-vivo testing, giving us a functional 
lattice-based biodegradable metal implant.",,,,,,
"['Yuan, Mengqi', 'Liu, Yu', 'Qian, Xinming']",2021-11-08T22:54:56Z,2021-11-08T22:54:56Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90066', 'http://dx.doi.org/10.26153/tsw/16987']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['stab resistant', 'body armor', 'carbon fiber', 'polyamide']",Material Selection on Laser Sintered Stab Resistance Body Armor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/466684ea-f92c-4dab-b626-acfa07926ffd/download,University of Texas at Austin,"Stab resistant body armor (SRBA) is essential defensive equipment to protect the human
body from injury due to stabbing. The conventional SRBAs are heavy and inflexible. Therefore a
new type of SRBA has been recently developed using Laser Sintering (LS), which has resulted in
a substantial improvement to SRBA in terms of structure and material design. In this
development, carbon fiber was employed in the polyamide matrix to obtain the optimal stab
resistant performances. Four kinds of materials were used and showed that the polyamide/carbon
fiber (PA/CF) composite improved the stab resistance property compared to pure polyamide (PA).
The stab resistance performances of flat plates were weaker than structured plates. The
penetration depth of the PA/CF structured plate was 2 mm less than the pure PA structured plate.
SEM observations of the products confirmed experimental conclusions that the addition of the
CF largely improved the plate stab resistance. Moreover, using the PA/CF structured plate to
produce SRBA would reduce the weight of the product by 30-40% comparing to the conventional
SRBA, which would greatly reduce the physical burden to the wearer and largely improve the
chance that the armor would be used.",,,,,,
"['Shanjani, Yaser', 'Toyserkani, Ehsan']",2021-09-23T21:49:29Z,2021-09-23T21:49:29Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88030', 'http://dx.doi.org/10.26153/tsw/14971']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['solid freeform fabrication', 'counter-rotating roller', 'powder-based solids', 'mechanical engineering']",Material Spreading and Compaction in Power-Based Solid Freeform Fabrication Methods: Mathematical Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bee2faf5-a7d5-460c-a6d7-5313374450c9/download,,"In this study, the spreading and compaction of powder by a counter-rotating roller, in the 
solid freeform fabrication (SFF) process, is modeled and characterized. The effect of layer 
thickness, roller diameter, amount of loose powder, and its initial density on the powder bed’s
relative density and roller compaction pressure is investigated.",,,,,,
"['Kietzman, J. W.', 'Prinz, F. B.']",2019-02-26T20:22:13Z,2019-02-26T20:22:13Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73497', 'http://dx.doi.org/10.26153/tsw/647']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SDM', 'support material']",Material Strength in Polymer Shape Deposition Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c03553e-25e3-45a5-904e-43b3cbb95d62/download,,"Shape Deposition Manufacturing (SDM) is a layered manufacturing process involving an
iterative combination of material addition and material removal. Polymer SDM processes have
used castable thermoset resins to build a variety of parts. The strength of such parts is determined
by the bulk material properties of the part materials and by their interlayer adhesion. This paper
describes tensile testing of three thermoset resins used for SDM - two polyurethane resins and one
epoxy resin. Both monolithic specimens and specimens with two interlayer !nterfaces were tested.
Interlayer tensile strengths were found to vary greatly among the three matenals, from 5-40 MPa.",,,,,,
"['Damas, Sara M.', 'Turner, Cameron J.']",2021-12-01T23:41:18Z,2021-12-01T23:41:18Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90660', 'http://dx.doi.org/10.26153/tsw/17579']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['conductive pathway', 'material testing', 'ABS', 'nanoparticles', '3D printing']",The Material Testing of Nanoparticle Doped 3D Printed ABS to Decrease Resistance and Create a Conductive Pathway,Conference paper,https://repositories.lib.utexas.edu//bitstreams/017d8e46-6e96-4203-9a7a-4170f5ba88a7/download,University of Texas at Austin,"The technology to 3D print by low-cost fabrication has been around since the 1970’s. Thanks
to one of its founding fathers, Scott Crump, as of 1989, it is possible to 3D print in low-cost
fabricated layers to obtain a solid component. The demand for 3D printed products has only gone
up since. Nickel, copper, carbon, and electric paint nanoparticles were bound to Acrylonitrile
Butadiene Styrene (ABS) using N-Methyl-2-Pyrrolidinone (NMP) by fused deposition modeling
(FDM). When ABS is doped with nanoparticles, conductive properties are introduced to the
filament which can then be used for strain measurements. This study concluded: When compared
to the other nanoparticles, nickel produced the lowest resistance when doped into the ABS.
Multiple layers of the NMP and nanoparticles yields a lower resistance, which subsequently yields
higher conductivity. The methodology outlined in this paper successfully created individually
isolated conductive pathways, where indeed NMP does improve the conductive performance of
the nanoparticles.",,,,,,
"['Song, Ruoyu', 'Telenko, Cassandra']",2021-10-28T15:48:31Z,2021-10-28T15:48:31Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89668,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['material waste', 'commercial FDM printers', 'fused deposition modeling', 'ABS material']",Material Waste of Commercial FDM Printers Under Realistic Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6c870239-3230-44b9-b1f3-3ea9e471329e/download,University of Texas at Austin,"Fused deposition modeling (FDM) is a prominent technology for additive manufacturing.
Additive manufacturing is thought to minimize material waste, but the actual material waste
could be larger than expected due to human or printer error. In FDM, the quantity of support
material is influenced by the part orientation and other settings of the printing. Additionally,
failures may result from insufficient preheating time, inappropriate geometry of parts, user error
or printer malfunctions. Material waste from commercial FDM printers using ABS material in a
heavily utilized open shop was collected in this study. The mass data of both support material
and failed prints were recorded over time. In addition, the failed prints were classified into 9
different categories and weighed according to failure reasons. The data were analyzed and
indicated that about 34% of the plastic used in the open studio was wasted. Only considering the
failed prints as the extra amount of material consumed under realistic conditions, the mass of
material lost to failed builds was about 2.22 times what might be estimated in a controlled
process study. Suggestions to reduce the material waste for each failure type are given.",,,,,,
"['Josupeit, Stefan', 'Rüsenberg, Stefan', 'Schmid, Hans-Joachim']",2021-10-07T15:18:52Z,2021-10-07T15:18:52Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88477', 'http://dx.doi.org/10.26153/tsw/15412']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['polymer laser sintering', 'nylon 12', 'part quality', 'aircraft industry']",A Material-Based Quality Concept for Polymer Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9cd7d1ea-d3d9-4796-ad7d-7c9f44ea3b8c/download,University of Texas at Austin,"In this work, the quality of laser sintered parts is investigated along a defined process chain for
a nylon 12 material (PA 2200) on an EOSINT P395 laser sintering system. Important influencing
factors are figured out. Rheological powder characterization methods are investigated as well as
mechanical, physical and other chosen part properties. The concept allows reproducible part quality
characteristics and is used to obtain (testing) temperature dependent material data. It can also be
extended on further materials based on nylon 12: PA 2241 FR, which is convenient for the aircraft
industry due to its flame-retardant properties, and PA 2221, which has economic advantages due
to a lower material consumption.",,,,,,
"Kimble, Luke L.",2018-04-19T18:15:45Z,2018-04-19T18:15:45Z,1992,Mechanical Engineering,doi:10.15781/T20V8B11S,http://hdl.handle.net/2152/64401,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'SLS', 'Selective Laser Sintering']",The Materials Advantage of the SLS Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8bb792f1-8875-4313-8a8c-6245a885fa46/download,,"The rapid prototyping market continues to progress in tenns of processes and materials
used for the creation of conceptual and functional parts and prototype tooling. As this market
continues to mature, the market leaders win be able to offer rapid prototyping processes and
materials that provide parts which are accurate, have good surface finish, and provide properties
which support fqnctional applications.. The materials used for these parts will be. polymers, metals,
and ceramics. '. The strength oithe SLSTM Selective Laser Sintering Process is the. potential to use a
wide variety of powdered materials for the creation of models, patterns, and some fonns of
prototype tooling. ,This paper will cover the types of materials currently used in the SLS process
and their inherent advantages.and discuss current research into the development of new materials.",,,,,,
"['Satapathy, S.', 'Hsieh, K.', 'Persad, C.']",2020-02-12T15:49:19Z,2020-02-12T15:49:19Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79943', 'http://dx.doi.org/10.26153/tsw/6969']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Electrical Conductor,Materials Design - Towards a Functionally Graded Electrical Conductor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/20df546b-31e6-45dd-9683-1a504bf398c5/download,,"In this study, we discuss functionally graded (FG) materials as pulsed electrical
conductors. These conductors can be designed to be more efficient and longer lasting by
applying numerical modeling tools. One focus is on limiting the thermal fatigue damage
in conductors caused by very high temperatures that develop during pulse heating. We
have quantified the effect of various grading functions on the pulsed Joule heating
generated and the peak temperature experienced in the conductors of an electromagnetic
launcher by using a 1D numerical code and a state of the art 3D coupled finite element
code, EMAP3D. Because FG materials incorporate applications-tailored compositions,
structures, and dimensions, smoothly graded properties in lateral and longitudinal cross
sections are obtainable. The Solid Freeform Fabrication (SFF) processing approach
allows for architectures with a series of important features. These features include the
selective use of high efficiency conducting materials in the core, preconditioned
conductor/structure interfaces, and built-in features for enhanced cooling where
necessary.",,,,,,
"['Barlow, J. W', 'Lee, G.', 'Aufdemorte, T. B.', 'Fox, W. C', 'Swain, L.D.', 'Vail, N.K']",2019-02-27T17:32:04Z,2019-02-27T17:32:04Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73506', 'http://dx.doi.org/10.26153/tsw/656']",,1998 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'porous']",Materials for Biomedical Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f6e974e-8e5e-44e6-8d03-cd43f5f6aba6/download,,"This paper discusses two ceramic material systems for selective laser sintering (SLS) that are
being developed for biomedical applications for use in repair of bone defects. SLS is the
preferred method of fabricating ceramic implants that exhibit well defined porous
microstructures. Implants fabricated in this. manner have proven effective in-vivo showing
excellent biocompatibility as well as considerable osseous integration and remodeling of the
imp'ant material",,,,,,
"['Cawley, J. D.', 'Liu, Z.', 'Mou, J.', 'Heuer, A. H.']",2019-02-26T17:23:11Z,2019-02-26T17:23:11Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73489', 'http://dx.doi.org/10.26153/tsw/639']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['densification', 'powder compact']",Materials Issues in Laminated Object Manufacturing of Powder-Based Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e64b4115-186f-4da2-a32e-9e9b87d14313/download,,"Laminated object manufacturing offine ceramic and powder metallurgy components can
be carried out using either the cut-then-stack or stack-then-cut motif. With either
approach, it is necessary to effect laser cutting to define layer geometry and lamination to
fuse the stack into a seamless monolith. The relationship between the microstructure of
the green tape used as feedstock on the relative ease of each process is reviewed",,,,,,
"['Schorzmann, J.', 'Gerstl, H.', 'Tan, Z.', 'Sprenger, L.', 'Lu, H.-H.', 'Taumann, S.', 'Wimmer, M.', 'Boccaccini, A.R.', 'Salehi-Muller, S.', 'Dopper, F.']",2024-03-27T15:51:08Z,2024-03-27T15:51:08Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124491', 'https://doi.org/10.26153/tsw/51099']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['bioreactor development', 'material screening methodology', 'additive manufacturing', 'material extrusion with thermal reaction bonding', 'biofabrication', '3D-bioprinting']",MATERIALS SCREENING METHODOLOGY FOR ADDITIVE MANUFACTURING IN BIOREACTOR TECHNOLOGY,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0107d2d1-8240-4bb2-bfef-d75f0d412aa6/download,University of Texas at Austin,"Biofabrication is used to fabricate complex tissues/organs inspired by their native structures
using additive manufacturing (AM) techniques and bio-inks (biopolymers enriched with living
cells). Electroactive cells such as skeletal muscle function via electrical signals and therefore,
their optimum in vitro functionality requires electrical conductivity and electrical stimulations.
AM can be used to precisely fabricate a bioreactor for a dynamic culture of cells and
bioengineered tissues and electrical stimulation of them. In this study, we focused on a material
selection methodology for AM of bioreactors with selective electrical conductivity based on
Reuter [1].
The important material requirements for bioreactors are biocompatibility, chemical stability,
electrical conductivity, and the capability of being sterilized. However, there is no standardized
procedure for selecting materials, that are appropriate for AM of bioreactors.
Our study comprises three phases which deductively narrowed down the material selection;
these phases are the determination of material requirements, pre-selection, and fine selection of
suitable materials. With the proposed method, a material selection for AM of functional
bioreactors (consisting of bioreactor housing and integrated additively manufactured electrodes
for electrical stimulation of the cells) could be efficiently made. For the bioreactor housing, two
of the investigated materials, high-temperature polylactic acid (HTPLA) and polypropylene
(PP) meet all requirements. The materials of the bioreactor electrodes could be narrowed down
to polyethylene with copper particles (PE-Cu) and poly lactic acid with graphene nanoplates
(PLA-GNP), where PE-Cu fulfilled all requirements besides the biocompatibility. PLA-GNP
matches all requirements besides the high temperature resistance. For a final selection of the
material for the bioreactor electrodes, further tests are required. However, this approach enabled
to reduce the amount of biocompatibility testing from 16 different materials to only four (-
75%), saving material, time, capacity and costs.",,,,,,
"['Lin, Feng', 'Sun, Wei', 'Van, Yongnian']",2019-03-12T15:49:33Z,2019-03-12T15:49:33Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73591', 'http://dx.doi.org/10.26153/tsw/733']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Layered Manufacturing', 'Rapid Prototyping']",A Mathematical Description of Layered Manufacturing Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/46356ecf-0481-4cbd-83dd-2563aa6b97f7/download,,"This study is attempted to use a mathematical definition to describe the principles of Layer Manufacturing
Processing. The concept of model decoll1Position (layered subtraction for 3D model slicing) and material
accumulation (layered addition for <prot()typjng fabrication) and the associated sequence function and
seql.lence· potential to explain·and define the layered manufacturing processing is presented. In the
mathematical description, a 3D CAD model is graphically represented by a set of points collected within
the bounded surfaces. In addition to its geometric feature, a processing sequence indicator is also assigned
to each point as an attribute to associate with its slicing and fabricating·sequence. Model decomposition
slices the collected. points into a series of point sets according to their sequence indicator, and material
accumulation processes the layered fabrication by stacking the point sets to form the designed object. A
scalar field function is used to express the variation of the sequence indicators for the selected point sets
and to define iso-sequence planes. The iso-sequence planes are the processing layers consisting of all
points with the same sequence indicator. Material accumulation is conducted in the gradient direction of
each iso-sequence plane. Example of using proposed scalar field function and the iso-sequence plane for
flat and no-flat layered prototyping processing is also presented.",,,,,,
"Dwivedi, Rajeev",2023-01-26T14:54:32Z,2023-01-26T14:54:32Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117312', 'http://dx.doi.org/10.26153/tsw/44193']",eng,2022 International Solid Freeform Fabrication Symposium,Open,maxel,maxel framework for representing and process planning of  Functionally Graded Materials.,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5655e96d-b341-4537-b447-7daa5fe416a3/download,,"Functionally Graded Materials (FGM) are characterized by variation in material composition or density per the 
required functionality. Inherent ability of various Solid Freeform Fabrication techniques to access bulk volume 
of part makes it a amenable to fabricating range of functionally graded materials. However, most of the Solid 
Free Form fabrication follow 2-1/2 additive process. In SFF manufacturing methods the tool path for each layer 
follows a Zig-zag or similar profile that necessarily is not most optimal path for material delivery. This may led 
to process inefficiencies. This paper presents a framework based on the maxel representation of materials to enable 
more efficient and accurate manufacturing of FGMs.",,,,,,
"['Rodriguez, J. F.', 'Thomas, J.P.', 'Renaud, J. E.']",2019-03-13T16:36:43Z,2019-03-13T16:36:43Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73644', 'http://dx.doi.org/10.26153/tsw/786']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Fused-Deposition', 'Solid Freeform Fabrication']",Maximizing the Strength of Fused-Deposition ABS Plastic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b6d19e26-edf2-420e-84b1-884f969ccf8a/download,,"Fused-Deposition (FD) creates parts using robotic extrusion of set.D.i-liquid .polymer
fiber, which molecularly bonds with neighboring fibers via thermal-dlffuslo.n bonding. T~e
strength ofthe. part depends on the bulk polymer strength, themesostructure ~flber layout, vOid
geom~try, extent of fiber bonding), and thefiber-t~-fiber ~ond strength. The ~nfluence of these
factors on the mechanical strength of FD-ABS.plasttc parts IS reported.along with the.FD process
variable settingsfor maximum strength. Substantial increases in transverse strength are achieved
at the optirnal settings and additional increases can be achieved by post..fabrication annealing.
Keywords: Stratasys, fused-deposition, ABSplastic, functional parts, strength, mesostructure, polymer diffusion.",,,,,,
"['Robinson, C. J.', 'Zhang, C.', 'Janaki Ram, G. D.', 'Siggard, E. J.', 'Stucker, B.', 'Li, L.']",2020-03-02T15:40:39Z,2020-03-02T15:40:39Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80136', 'http://dx.doi.org/10.26153/tsw/7157']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic Consolidation,Maximum Height to Width Ratio of Freestanding Structures Built Using Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbf462a5-8a87-47e5-b7da-a9a6c29ef174/download,,"Ultrasonic consolidation (UC) is a process whereby metal foils can be metallurgically
bonded at or near room temperature. The UC process works by inducing high-speed differential
motion (~20kHz) between a newly deposited layer and a substrate (which consists of a base plate
and any previously deposited layers of material). This differential motion causes plastic
deformation at the interface, which breaks up surface oxides and deforms surface asperities,
bringing clean metal surfaces into intimate contact, where bonding occurs. If the substrate is not
stiff enough to resist deflection during ultrasonic excitation of newly deposited layers, then it
deflects along with the newly deposited layer, resulting in no differential motion and lack of
bonding. Geometric issues which control substrate stiffness and deflection were investigated at
Utah State University by building a number of free-standing rib structures with varying
dimensions and orientations. Each structure was built to a height where lack of bonding between
the previously deposited layers and the newly deposited layer caused the building process to fail,
a height to width ratio (H/W) of approximately 1:1. The parts were then cut, polished, and
viewed under a microscope. An ANSYS model was created to investigate analytically the cause
of this failure. It appears build failure is due to excessive deflection of the ribs around a 1:1 H/W,
resulting in insufficient differential motion and deformation to achieve bonding. Preliminary
results show, when the H/W reaches 1:1, the von Mises stress is found to be tensile along
portions of the bonding interface, which eliminates the compressive frictional forces necessary
for plastic deformation and formation of a metallurgical bond. These tensile stresses are shown
to be concentrated at regions near the edges of the newly deposited foil layer.",,,,,,
"['Young, Y.Y.', 'Yu, K.M.', 'Kwong, C.K.']",2019-10-18T15:17:46Z,2019-10-18T15:17:46Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76235', 'http://dx.doi.org/10.26153/tsw/3324']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Jewel Rings,Maximum Visibility Building Direction for Layered Manufacturing of Jewel Rings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e52cab88-49fa-4c9e-a1e6-8272b081b690/download,,"Rapid prototyping is used in jewelry production since the introduction of
Stereolithography Apparatus into the market. However, the building orientation is
mainly decided by the experience of the operator rather than by any systematic
analysis. A theory is therefore needed to analyze the best orientation of jewelry in
rapid jewelry production. In this paper, a new orientation methodology is applied to
jewel ring models to properly orient them for layer manufacturing. Jewel ring model
built is then demonstrated to have better quality and less error. A case study is
presented to illustrate the theory.","The work described in this paper was supported by a grant from the Hong
Kong Polytechnic University (Project No.: G-V617).",,,,,
"['Gupta, Guarav', 'Tan, JunJay', 'Seepersad, Carolyn Conner']",2020-03-02T14:33:41Z,2020-03-02T14:33:41Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80126', 'http://dx.doi.org/10.26153/tsw/7147']",eng,2006 International Solid Freeform Fabrication Symposium,Open,cellular materials,ME Design and Freeform Fabrication of Compliant Cellular Materials with Graded Stiffness,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68ab06e4-9007-441b-ac86-a537f0446519/download,,"Typically, cellular materials are designed for structural applications to provide stiffness or
absorb impact via permanent plastic deformation. Alternatively, it is possible to design compliant
cellular materials that absorb energy via recoverable elastic deformation, allowing the material to
spring back to its original configuration after the load is released. Potential applications include
automotive panels or prosthetic applications that require repeated, low-speed impact absorption
without permanent deformation. The key is to arrange solid base material in cellular topologies
that permit high levels of elastic deformation. To prevent plastic deformation, the topologies are
designed for contact between cell walls at predetermined load levels, resulting in customized,
graded stiffness profiles. Design techniques are established for synthesizing cellular topologies
with customized compliance for static or quasi-static applications. The design techniques
account for cell wall contact, large scale deformations, and material nonlinearities. Resulting
cellular material designs are fabricated with selective laser sintering, and their properties are
experimentally evaluated.",,,,,,
"['Kulkarni, N.P.', 'Sparks, T.E.', 'Tandra, G.', 'Liou, F.W.']",2021-10-01T00:01:15Z,2021-10-01T00:01:15Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88301', 'http://dx.doi.org/10.26153/tsw/15242']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['fuel cell', 'Membrane Electrode Assembly', 'polymer-electrode membrane', 'selective deposition', 'catalyst', 'cost reduction']",MEA Manufacturing Using an Additive Manufacturing Process to Deposit a Catalyst Patter in an MEA and its Impact on Cost Reduction,Conference paper,https://repositories.lib.utexas.edu//bitstreams/337fbed3-92b0-4970-842d-4c2069a18d3f/download,University of Texas at Austin,"The manufacturing of a fuel cell Membrane Electrode Assembly (MEA) is a significant cost
driver in polymer-electrolyte membrane (PEM) fuel cell technologies, primarily due to the
inclusion of expensive materials in the catalyst layer. The selective deposition of a catalyst on the
MEA of a fuel cell can drastically reduce the costs depending upon the catalyst, method used for
deposition, and production volume. In this paper, testing and analysis of a novel catalyst iridium
oxide is discussed. The performance of the catalyst will be compared with the conventional
catalysts which will give us an estimate of its effectiveness however, in this paper, only its
feasibility in terms of cost is discussed.",,,,,,
"['Chalancon, Antoine', 'Bourell, David']",2021-11-01T21:47:14Z,2021-11-01T21:47:14Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89767,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['energy density', 'polyamide 12', 'laser sintering']",Measured Energy Densities for Polyamide 12 and Comparison of Values Calculated for Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9edc7ece-f767-457b-a8cc-25c1c4a2da87/download,University of Texas at Austin,"Energy density is a key factor in the Laser Sintering (LS) process, and impacts the
properties of the built parts. Processing parameters have an important effect on Laser
Sintering. This paper focuses on the evaluation of various energy density equations.
Experiments were carried out by varying processing parameters, namely, laser power,
scan speed, hatch distance/scan spacing and layer thickness to change actual and
calculated energy density. Relative density was estimated using the Archimedes method
and mensuration. As a result, a correlation between the laser energy density and the
relative density has been established. Finally, the effect of parameters is discussed.",,,,,,
"['Dvorak, Jake', 'Ajinjeru, Christine', 'Smith, Tyler', 'Kim, Seokpum', 'Hershey, Christopher', 'Lindahl, John', 'Kunc, Vlastimil', 'Duty, Chad']",2021-11-18T17:22:15Z,2021-11-18T17:22:15Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90435', 'http://dx.doi.org/10.26153/tsw/17356']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['pressure profiles', 'pressure distributions', 'single screw extruder', 'big area additive manufacturing', 'BAAM']",Measurement and Analysis of Pressure Profile Within Big Area Additive Manufacturing Single Screw Extruder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e09c94ca-4713-4a64-833a-d434c0115c39/download,University of Texas at Austin,"Pressure distributions within a single screw extruder are dependent on several factors,
namely, processing parameters and flow geometry. The Big Area Additive Manufacturing
(BAAM) system involves a complex flow geometry with multiple flow zones following the screw
extruder. This study utilized experimental data and a one-dimensional (1-D) analytical model to
compare pressures at specific areas of interest in the BAAM system. Initial results show a need
for further two-dimensional (2-D) and three-dimensional (3-D) simulation and modeling of the
BAAM extruder with more accurate underlying assumptions. The results of this work will allow
for further study of BAAM input parameters for optimal print quality, material properties, and
print head geometric design.",,,,,,
"['Klingbeil, N.W.', 'Beuth, J.L.', 'Chin, R.K.', 'Amon, C.H.']",2019-02-22T20:05:09Z,2019-02-22T20:05:09Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73471', 'http://dx.doi.org/10.26153/tsw/621']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SDM']",Measurement and Modeling of Residual Stress-Induced Warping in Direct Metal Deposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0cbd1ff-4247-4d8d-98c1-fb2becbe36dc/download,,"Tolerance loss due to residual stress-induced warping is a major concern in solid freeform
fabrication (SFF) processes. An understanding of how residual stresses develop and how they
lead to tolerance loss is a key issue in advancing these processes. In this paper, results are
presented from warping experiments on plate-shaped specimens created by microcasting and
welding processes used in Shape Deposition Manufacturing (SDM). Results from these
experiments give insight into differences between the two processes, the role of preheating and
insulating conditions during manufacture and the influence of deposition path on magnitudes and
distributions of warping displacements. Results are then compared to predictions from two types
of residual stress models. While the models effectively predict warping magnitudes and the effects
of various thermal conditions, they are unable to capture some of the more subtle trends in the
experiments. Results from the experiments and numerical models suggest that a combination of
initial substrate preheating and part insulation can be applied to SDM and similar SFF processes to
limit warping deflections, which is substantially simpler than active control of part temperatures
during manufacture. Results also suggest that 3-D mechanical constraints are important in
achieving precise control of warping behavior in SFF processes.",,,,,,
"['Sumin Sih, Samuel', 'Barlow, Joe W.']",2018-10-03T16:50:51Z,2018-10-03T16:50:51Z,1994,Mechanical Engineering,doi:10.15781/T2KH0FJ02,http://hdl.handle.net/2152/68665,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'hydroxyapatite powder', 'thermal conductivity of power beds']",Measurement and Prediction of the Thermal Conductivity of Powders at High Temperatures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/18e41ece-472c-4262-9850-c16bc182e09e/download,,"An equation for the prediction of the thermal conductivity of
powder beds up to high temperatures is suggested by the authors.
The predicted values by the equation are compared with the values
of the thermal conductivity of alumina powder, magnesia powder
and zirconia powder reported in the literature, and are found to be
consistent. The predicted values by the equation are also compared
with the measured values of the thermal conductivity of calcium
hydroxyapatite powder, at various temPeratures, up to 500°C by the
laser-heated method.",,,,,,
"['Klingbeil, N.W.', 'Zinn, J.W.', 'Beuth, J.L.']",2018-11-28T21:25:24Z,2018-11-28T21:25:24Z,1997,Mechanical Engineering,doi:10.15781/T25X25Z66,http://hdl.handle.net/2152/70332,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SDM process', 'Microcasting']",Measurement of Residual Stresses in Parts Created by Shape Deposition Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc99ca1b-ed6f-43cc-81fd-fa5c9fc571c5/download,,"Residual stress build-up is a concern in any solid freeform fabrication process involving
successive deposition of uncured or molten material, due to differential contractions caused by
solidification or curing. The most detrimental effect of residual stresses is typically part warping,
which can lead to unacceptable losses in part tolerance. In many processes residual stress build-up
is a fundamental barrier to the consistent manufacture of high-quality artifacts. In this paper, two
methods of measuring residual stresses in parts created by Shape Deposition Manufacturing (SDM)
with microcasting are described. First, a technique for measuring warping in deposited plateshaped
specimens is detailed, which can be used to determine residual stress resultants as well as
to quantify gross effects of processing changes on residual stress magnitudes. Next, x-ray
diffraction procedures are described by which residual stresses in deposited layers can be measured
at discrete in-plane locations as a function of depth. Measured results for 308L stainless steel
deposits determined from each method are interpreted in the context of residual stress modeling
results obtained numerically in a separate research effort. The measured results provide insight
into the effects on residual stress of both the material deposition path and the discrete droplet-bydroplet
nature of the microcasting deposition process. The insights provided here may also be
applicable to other processes involving successive material deposition.",,,,,,
"['Steinberger, J.', 'Manetsberger, K.', 'Shen, J.', 'MulIers, J.']",2019-03-13T16:18:15Z,2019-03-13T16:18:15Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73640', 'http://dx.doi.org/10.26153/tsw/782']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'electromagnetic']",Measurement of the Sintering Dynamics of polymeric powders at Near SLS Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d4f5048-b14d-469d-b508-755734177604/download,,"The sintering dynamics of materials used in the Selective Laser Sintering process impact
greatly the thermal conditions of the powder bed. An experimental setup was developed to
obtain sintering rate information at conditions very near to those of the SLS process. The
system consists of a powder sample heated by a CO2 laser while maintained at constant
thermal boundary conditions. The powder height is measured by means of an optical sensor,
which avoids stress on the powder and allows fast data. acquisition. This paper discusses
experiments conducted with this apparatus and further compares the obtained results with
theoretical models and the previous work of others.",,,,,,
"['Sih, Samuel S.', 'Barlow, Joel W.']",2018-05-03T20:04:24Z,2018-05-03T20:04:24Z,1993,Mechanical Engineering,doi:10.15781/T2BG2HT54,http://hdl.handle.net/2152/65081,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Chemical Engineering Department', 'sintering', 'laser-heat', 'thermal']",Measurement of the Thermal Conductivity of Powders by Two Different Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e2a9f46-5368-410f-b34a-d909d1029617/download,,"The thermal diffusivities and thermal conductivities of powders, especially PMMA-coated
silicon carbide, at various temperatures, have been tested by two different dynamic methods, the
water-bath method and the laser-heated method. The thermal conductivity data found by these two
techniques are found to be consistent with each other.",,,,,,
"['Sih, Samuel S.', 'Barlow, Joel W.']",2018-04-19T17:25:44Z,2018-04-19T17:25:44Z,1991,Mechanical Engineering,doi:10.15781/T2JS9HR3W,http://hdl.handle.net/2152/64389,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Chemical Engineering Department', 'polymer powders', 'SLS']",The Measurement of the Thermal Properties and Absorptances of Powders Near their Melting Temperatures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f75d6fe-d37e-473f-9e1f-5e1e9841dca4/download,,"A new technique, using a laser as the heating source, has been adopted to measure the heat
capacities, thermal diffusivities, thermal conductivities, and absorptances of powders (especially
polymer powders) near their melting temperatures. This makes use of an unsteady state process.
The data of the thermal conductivities obtained through this technique below 100°C are in concord
with the values obtained through the other techniques, which predicts well for the use of this
technique for still higher temperatures, up to the melting temperatures of the powders to be
investigated.",,,,,,
"['Fly, David E.', 'Gradowski, Anita', 'Espalin, David', 'Winker, Rob', 'Rask, Josh']",2021-10-18T20:24:48Z,2021-10-18T20:24:48Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89233,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['CMM', 'gauge blocks', 'gauge pins', 'calipers', 'FDM', '3D printing', '3D scanning', 'error compensation', 'sources of variation']",Measurement Systems Comparison on Various Feature Sizes of FDM Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd22a743-7b1b-4e9d-aeae-90cbeef26dff/download,University of Texas at Austin,"12 identical FDM parts were produced in ABSM30, each having 16 features for replicated
measurements. Half the features were positive (posts), half were negative (holes). Half of all
features were rectangular, half were round. Two different CMMs with 1.5mm touch probes were
compared, one CMM additionally used a laser, and manual measurements were taken with
gauges and calipers. All features were measured using these 4 measurement systems. All
measurements were compared against the theoretical feature size to generate a percent error
value. The laser values were notably different than both probe values. The manual
measurements were similar to one of the two CMM probes. Positive versus negative features
were significantly different in 7 of 8 cases. Feature size and measurement error were inversely
proportional. The largest features had the least amount of error in all cases while the features
below 6mm had the most error and high variation.",,,,,,
"['Fodran, Eric', 'Koch, Martin', 'Menon, Unny']",2018-11-14T20:58:25Z,2018-11-14T20:58:25Z,1996,Mechanical Engineering,doi:10.15781/T20V8B325,http://hdl.handle.net/2152/70266,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'mechanical properties', 'polymer materials']",Mechanical and Dimensional Characteristics of Fused Deposition Modeling Build Styles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b21f67dd-9ccc-4c33-8fb0-a03e3576b30a/download,,"As rapid prototyping becomes more prominent, industry relies more on
the mechanical properties of the builds. Fused Deposition Modeling (FDM)
tensile samples were constructed and tested in order to characterize the
mechanical properties of Acrylonitrile Butadiene Styrene (ABS) FDM builds.
Parameters such as fill gap, line width, and slice thickness were varied in the
production of the FDM samples. This was performed independently to isolate the
effect of each parameter on mechanical properties. Results include the ultimate
tensile strength, yield strength, elongation, energy to fracture, modulus of
elasticity, and dimensional analysis. High magnification fracture surface analysis
was also be performed to aid in the characterization of sample failures.",,,,,,
"['Rüsenberg, S.', 'Schimdt, L.', 'Schmid, H.-J.']",2021-10-04T21:28:03Z,2021-10-04T21:28:03Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88352', 'http://dx.doi.org/10.26153/tsw/15291']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['physical properties', 'mechanical properties', 'laser sintered parts', 'polyamide parts']",Mechanical and Physical Properties - A Way to Assess Quality of Laser Sintered Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a614c87e-dce4-44cc-a0f9-52fee509c73a/download,University of Texas at Austin,"The aim of this paper is the description and evaluation of physical properties like porosity and density
and their influence on mechanical properties of laser sintered polyamide parts. For example, by reducing the
porosity an increase of mechanical properties is possible. The correlation of laser parameters to these properties
is investigated in detail. The energy density is an important parameter for the laser sintering process. By
changing laser power, scan velocity and hatch distance an influence on manufactured components is given. A
systematic variation of all three laser parameters is performed. A comparison of results obtained at constant
energy densities obtained by varying these relevant parameters accordingly is shown as well.",,,,,,
"['Venkataraman, N.', 'Rangarajan, S.', 'Matthewson, M.J.', 'Safari, A.', 'Danforth, S.C.', 'Yardimci, A.', 'Guceri, S.I.']",2019-03-15T15:49:49Z,2019-03-15T15:49:49Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73685', 'http://dx.doi.org/10.26153/tsw/827']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Fused deposition of ceramics', 'solid freeform']",Mechanical and Rheological Properties of Feedstock Material for Fused Deposition of Ceramics and Metals (FDC and FDMet) and their Relationship to Process Performance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1910680e-5974-4d56-9fd4-8d86904537e7/download,,"Fused deposition of ceramics (FDC) is a solid freeform fabrication technique based on
extrusion of a highly loaded thermoplastic binder system. The present FDC process uses filament
feedstock of 1.780 mm ± 0.025 mm diameter. The.filament acts as both the piston driving the
extrusion process as well as the molten feedstockbeing deposited. The filaments need to be able
to provide and sustain the pressure needed to drive the extrusion process. Failure to do this
results in failure via ""buckling"". The filament compressive modulus determines the ability ofthe
filament to provide·and sustain the required pressure to drive the extrusion. The viscosity ofthe
feedstock material, nozzle geometry and volumetric flow rates employed determine the pressure
needed to drive the extrusion process. In this worktheiextrusion pressure for a particular material
termed PZT ECG9 (52.6 Vol.% PZT powder in ECG9i~inder) was measured experimentally as a
function of volumetric flow rate and nozzle geometry.rhe compressive modulus ofthe material
was determined using a miniature materials tester (Rheoinetrics, Inc., Piscataway, NJ). A process
map has been developed. The map is based .on the quantity MIE, and predicts the performance
of the material in a FDC process as a.functioIl.ofnozzleg~ometry and volumetric flow rate. In
general, it is observed that when MIE exceeds a critical value, called APcr/E, there is an
increased tendency for the filament to buckle. A. preliminary fluid flow model for extrusion of
PZT ECG9 through a FDC nozzle has also been developed using Polyflow™ software. The
model predicts the observed trend in pressure drop with flow rate and nozzle geometry with
reasonable accuracy.",,,,,,
"['Knoop, F.', 'Schoeppner, V.']",2021-10-21T15:13:54Z,2021-10-21T15:13:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89391,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'polyamide 12', 'mechanical properties', 'thermal properties']",Mechanical and Thermal Properties of FDM Parts Manufactured with Polyamide 12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e34de4f-e770-4211-8b49-2535ecfa293f/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) is an Additive Manufacturing (AM) technology which
is used for prototypes, single-part production and also small batch productions. For use as a final
product, it is important that the parts have good mechanical properties, high dimensional accuracy
and smooth surfaces. The knowledge of the mechanical properties is very important for the design
engineer when it comes to the component design. End-use products out of the FDM process have
to resist applied forces. In this paper, investigations were conducted with the polymer Polyamide 12
(FDM Nylon 12) from Stratasys Inc. This polymer can be processed with three different tip sizes
resulting in different layer thicknesses from 178 μm to 330 μm. Thus, the mechanical properties
were determined for these layer thicknesses and for different orientations on the build platform. In
addition to the mechanical properties the thermal properties (e.g. with a DSC analysis) are also
investigated.",,,,,,
"['Davies, S.J.', 'Jeffs, S.P.', 'Lancaster, R.J.', 'Baxter, G.']",2021-11-02T14:14:39Z,2021-11-02T14:14:39Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89810,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['small punch tensile test', 'nickel superalloy', 'laser powder bed fusion', 'LPBF', 'build orientation', 'heat treatment']",Mechanical Assessment of a LPBF Nickel Superalloy Using the Small Punch Test Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/22c632bd-dfaf-45bc-8a0e-6616b952d30a/download,University of Texas at Austin,"With the continuous drive of the aerospace industry to introduce Additive Layer
Manufacturing (ALM) into next generation gas turbine engines, the requirement to understand
their mechanical performance has grown. However, limitations in material availability due to the nature
of the process can restrict the scope for conventional mechanical testing. The Small Punch Tensile
(SPT) test provides an effective tool for ranking the performance of ALM processed alloys, credited
to the small volumes of material utilised and the ability to sample localised regions. This technique has
been applied to the nickel superalloy C263, manufactured via Laser Powder Bed Fusion (LPBF) in
different build orientations and subjected to contrasting post process heat treatments. To fully
understand the effects of these process variables on the mechanical response of LPBF alloys, empirical
correlations have been derived between SPT and uniaxial data attempting to demonstrate the suitability of
this approach in characterising the properties of ALM structures.",,,,,,
"['Guivier, Manon', 'Kuebler, Jesse', 'Swanson, Trevor', 'Lawson, Christopher', 'Fernandez-Ballester, Lucia', 'Negahban, Mehrdad', 'Sealy, Michael P.']",2021-12-07T18:45:32Z,2021-12-07T18:45:32Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90754', 'http://dx.doi.org/10.26153/tsw/17673']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['hybrid additive manufacturing', 'fused filament fabrication', 'polymer', 'ultrasonic peening']",Mechanical Behavior of ABS after Interlayer Ultrasonic Peening Printed by Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a357eba2-dd85-4068-bb9b-e29adc3e0c6b/download,University of Texas at Austin,"Hybrid additive manufacturing brought new opportunities to improve the mechanical
properties of materials by secondary processing of individual layers during printing. Previous
work demonstrated interlayer shot peening during printing by fused filament fabrication (FFF)
affected mechanical behavior while inadvertently imparting debris contamination from
pulverized beads. The encouraging results motivated a study on the use of contamination free
ultrasonic peening (UP) as an alternative interlayer surface treatment. Ultrasonic peening of
FFF printed Acrylonitrile Butadiene Styrene (ABS) was studied in order to compare the effects
on mechanical properties between ultrasonic peening and previously studied shot peening,
different print orientations, and different interlayer peening frequencies. Two different layer
peening frequencies (L4 and L8) were compared to an as-printed control (L0). Two orientations
for each layer peening frequency were chosen for comparison. Tensile tests were conducted in
order to observe the influence of interlayer UP on tensile strength of ABS parts.",,,,,,
"['Shrestha, Rakish', 'Sterling, Amanda', 'Lessel, Brandon', 'Phan, Nam', 'Sereshk, Mohammad Reza Vaziri', 'Shamsaei, Nima']",2021-11-09T20:07:50Z,2021-11-09T20:07:50Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90151', 'http://dx.doi.org/10.26153/tsw/17072']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['monotonic tensile test', 'lattice', 'schoen gyroid structure', 'additive manufacturing', '17-4 PH SS']",Mechanical Behavior of Additively Manufactured 17-4 PH Stainless Steel Schoen Gyroid Lattice Structure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/30f4d075-1bd5-45b6-8383-36d1c601d262/download,University of Texas at Austin,"In this study, the mechanical properties of additively manufactured 17-4 PH stainless steel
Schoen Gyroid lattice structures were investigated under monotonic tensile loading. Based on the
results obtained from the monotonic tensile test, relationship between tensile properties and
relative density of Schoen Gyroid was also established based on the Gibson-Ashby equations. Four
different types of gyroid structures with varying volume fractions were designed by altering
thickness and length of the unit cell and then fabricated in horizontal direction using a laser powder
bed fusion (L-PBF) process. Monotonic tensile tests were conducted under displacement control
mode with the speed of cross head movement set to be equivalent to the strain rate of 0.001 s-1
.
Monotonic tensile results showed a decrease in stiffness and a slight increase in elongation to
failure with the decreasing volume fraction among different lattice structures. A good correlation
between the material properties (maximum force and stiffness) and volume fraction was also
obtained using Gibson-Ashby type relationship. Furthermore, maximum force normalized by the
volume per unit length was calculated to determine the effect of cell thickness and length on the
resulting mechanical properties. Normalized force versus displacement plot illustrated an increase
in stiffness with the increase in unit cell thickness. Whereas, lattice structures with similar cell
length and cell thickness exhibited similar normalized maximum force as well as stiffness values.",,,,,,
"['Sereshk, Mohammad Reza Vaziri', 'Shrestha, Rakish', 'Lessel, Brandon', 'Phan, Nam', 'Shamsaei, Nima']",2021-11-30T21:42:03Z,2021-11-30T21:42:03Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90559', 'http://dx.doi.org/10.26153/tsw/17478']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'gyroids', 'heat treatment', 'mechanical behavior', 'post-processing', 'laser beam powder bed fusion']",Mechanical Behavior of Additively-Manufactured Gyroid Lattice Structure under Different Heat Treatments,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f8757c6-fefb-4e77-a6d2-978e0fca58c3/download,University of Texas at Austin,"Gyroid lattice structures, known for high stiffness and specific strength, are gaining
attention for their energy absorption ability. However, energy absorption and strength of the
gyroids are two desired properties, which vary contradictory. This study investigates manipulating
properties on lattices using post-processing operation instead of modifying dimensions with
consequent changes in weight and production cost. The challenge is that a particular post-processing heat treatment may improve one property, while it may be detrimental to other ones.
The compressive properties of 17-4 PH stainless steel gyroid lattice structures fabricated using
laser beam powder bed fusion (LB-PBF) method is investigated. Compressive properties such as
load bearing capacity, crashing strength, and energy absorption are determined and the trends in
their variation are discussed. Based on the experimental results, heat treating lattices with CA
H900 procedure improves energy absorption and strength considerably, while increases crashing
force, as well.",,,,,,
"['Wang, Mei', 'Zhou, Yan', 'Wei, Q.S.', 'Fan, Zhunfeng']",2021-11-10T22:50:00Z,2021-11-10T22:50:00Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90198', 'http://dx.doi.org/10.26153/tsw/17119']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['AISI H13', 'hot-work', 'tool steel', 'tensile stress', 'mechanical behavior', 'selective laser melting']",The Mechanical Behavior of AISI H13 Hot-Work Tool Steel Processed by Selective Laser Melting under Tensile Stress,Conference paper,https://repositories.lib.utexas.edu//bitstreams/40654d69-2e18-4209-a70e-9ad2ec5799c2/download,University of Texas at Austin,"AISI H13 tool steel is commonly used in hot-working applications include die casting dies,
inserts, forging dies, extrusion dies, etc. Molds fabricated by selective laser melting (SLM) with
conforming cooling channels can maintain a steady and uniform cooling performance to the
molding parts, which ensures high quality of the products and general reduction of the cycle time.
Therefore, SLM process has gained increasing attention in the hot-work tool field. The present
study concerns the properties of H13 materials that with and without preheating during the SLM
process. X-ray diffraction (XRD), field emission scanning electron microscope (SEM), and high-temperature tensile tests were applied to investigate the phases, microstructures and resultant
mechanical properties of SLM processed H13. Results show that the application of preheating
during SLM process results in a more homogeneous microstructure of the material with better
mechanical properties compared to those without preheating. High-temperature tensile strength
increased from 1066 MPa to 1183 MPa, the total elongation increased from 5.7% to 8.1%. The
high-temperature tensile strength of those parts with preheating was higher than those of the
treated commercial H13 tool steel, while the total elongation was much lower than those
commercial materials.",,,,,,
"['Jiang, D.', 'Smith, D.E.']",2021-10-27T22:54:53Z,2021-10-27T22:54:53Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89640,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fused filament fabrication', 'carbon fiber', 'mechanical behavior']",Mechanical Behavior of Carbon Fiber Composites Produced with Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be8b30df-5bac-4f49-8386-0d29e97ba227/download,University of Texas at Austin,"Fused Filament Fabrication (FFF) is a commonly used Additive Manufacturing (AM)
technique. However, the printed parts often lack sufficient mechanical integrity. Recently,
mechanical properties of FFF filament have been enhanced by blending pure polymer with short
carbon fibers. This paper presents a study of the mechanical properties for carbon fiber filled (CFF)
FFF parts produced with Makerbot printers. Polymer composite and pure polymer tensile test
coupons are printed and then tested following ASTM D3039M. Here we consider FFF print
orientations that are aligned with the test bar axis at 0 degree, 45 degrees, ±45 degrees, and normal
to the bar axis at 90 degrees. The filament considered here was purchased from filament suppliers
and included PLA, ABS, and PETG. Results are presented for tensile strength and tensile modulus.
Additionally, short fiber composite samples are evaluated for fiber length distribution (FLD) and
fiber weight fraction. Fracture surfaces are evaluated under SEM.",,,,,,
"['Denham, Hugh B.', 'Cesarano III, Joseph', 'King, Bruce H.', 'Calvert, Paul']",2019-02-26T20:49:31Z,2019-02-26T20:49:31Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73500', 'http://dx.doi.org/10.26153/tsw/650']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['ceramic', 'strength']",Mechanical Behavior of Robocast Alumina,Conference paper,https://repositories.lib.utexas.edu//bitstreams/95deb3e9-8efd-4ef3-8628-c9ae2919dcd0/download,,"Direct fabrication of alumina parts by robocasting was completed. This method is based
on three-dimensional deposition of binderless aqueous alumina slurries. Parts were made with
different deposition paths and mechanical·testing performed·to determine the effects •of bead
alignment. Properties were also compared to. alumina processed more traditionally",,,,,,
"['Amado-Becker, Felipe', 'Díaz, Richard A.', 'Ramos-Grez, Jorge']",2020-03-05T20:06:16Z,2020-03-05T20:06:16Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80154', 'http://dx.doi.org/10.26153/tsw/7175']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Mechanical Behavior of SLS Components in Relation to the Build Orientation During the Sintering Process as Measured by ESPI,Conference paper,https://repositories.lib.utexas.edu//bitstreams/afb3e679-633c-4a3a-af66-56b43f2b0f8f/download,,"Selective Laser Sintering (SLS) allows producing real parts from CAD data from materials with
different characteristics compared to the final model, presenting dissimilar mechanical properties
between the prototype and the product. The purpose of this work is to correlate the mechanical
behavior of beam-type specimens produced by SLS with build orientation angle used as a process
parameter, also attempting to demonstrate how this parameter affects the accuracy of the
Empirical Similitude Method (ESM). ESM presents itself as a valuable tool when creating scale
models with SLS, specifically in the framework of evolutionary product design. More
specifically, the Young modulus variation of test specimens of well-known dimensions and
material (DuraformTM PA2
), will be characterized by loading them within the elastic range. The
resulting elastic deformations will be measured using the technique of Electronic Speckle Pattern
Interferometry (ESPI) for small deformations in an out-of-plane configuration, contrasting these
results with the elastic theory of deformations. As a main result, it was found that there exists a
linear correlation between the build angle and the elastic modulus of the parts. Secondly, it was
demonstrated empirically that the ESM predicts better the mechanical response of the part than
TSM. Moreover, a 30% error reduction can be achieved within the ESM when using the build
orientation angle as a process parameter.",,,,,,
"['Roach, M.A.', 'Keicher, D.', 'Maines, E.', 'Wall, B.', 'Wall, C.', 'Lavin, J.', 'Whetten, S.', 'Evans, L.']",2021-11-10T21:18:28Z,2021-11-10T21:18:28Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90178', 'http://dx.doi.org/10.26153/tsw/17099']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['ceramics', 'alumina', 'mechanical challenges', '3D printing', 'digital light processing', 'stereolithography']",Mechanical Challenges of 3D Printing Ceramics Using Digital Light Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c54b3e1b-f474-444e-b873-c8148675400b/download,University of Texas at Austin,"Digital light processing (DLP) 3D printing can be used for manufacturing complex
structures using a variety of materials, which would be nearly impossible using traditional
manufacturing methods. Recent work at Sandia National Laboratories uses DLP technology for
additive manufacturing of complex alumina structures, using photocurable resins loaded with
micron or submicron alumina particles. These resins are printed using a DLP 3D printer to
produce a “green part.” The work presented here will discuss the mechanical challenges
associated with printing alumina using commercially available DLP and stereolithography 3D
printers, including the design of a custom DLP 3D printer to address identified mechanical
challenges, thereby leading to improved print versatility and quality.",,,,,,
"['Bertoldi, M', 'Yardimci, M', 'Pistor, C. M.', 'Guceri, S. I', 'Sala, G']",2019-02-26T20:20:28Z,2019-02-26T20:20:28Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73496', 'http://dx.doi.org/10.26153/tsw/646']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'polymer-based material']",Mechanical Characterization of Parts Processed via Fused Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e6c667b-678c-49f1-bb67-2b1bb5c0a8fd/download,,"The possibility of using materials with better physical and mechanical properties together
with the quickly improving capabilities of various processes increasingly make Rapid
Prototyping (RP) as a new manufacturing technology for specialty components.
In Fused Deposition Modeling (FDM), the build orientation and the toolpath used
strongly affect the properties of the part. This study presents the results of experimental work
based on mechanical characterization of parts fabricated with fused deposition to determine the
stiffness matrix and the thermal expansion coefficients for an equivalent orthotropic material.
The results can be directly adapted into computational analysis tools based on classical
lamination theory, for part quality and performance prediction. Current investigation focuses on
use ofABS material in Stratasys FDM 1650 rapid prototyping equipment.",,,,,,
"['Correa, Dixon', 'Bostwick, Ken', 'Wilson, Preston S.', 'Haberman, Michael', 'Seepersad, Carolyn Conner']",2021-10-21T19:21:49Z,2021-10-21T19:21:49Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89428,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['negative stiffness honeycombs', 'impact', 'impact performance', 'additive manufacturing']",Mechanical Impact Performance of Additively Manufactured Negative Stiffness Honeycombs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13044470-bbae-4a04-8fb8-03b4d887d6cd/download,University of Texas at Austin,"Negative stiffness honeycombs materials are comprised of negative stiffness beams
arranged in ordered arrays. They are capable of providing isolation from impacts and returning
to their initial shape. Previous research by the authors focused on the behavior of negative
stiffness honeycombs to quasi-static loading conditions. This paper investigates the behavior of
similar negative stiffness honeycombs under impact. The construction of an impact testing rig for
the experimental evaluation of negative stiffness honeycombs is discussed. Experimental results
from impact tests performed on honeycomb prototypes manufactured using selective laser
sintering (SLS) in nylon 11 material are presented and compared with analytical and finite
element predictions as well as quasi-static test results.",,,,,,
"['Weflen, E.D.', 'Ginther, M.C.', 'Eldakroury, M.A.', 'Frank, M.C.']",2021-12-07T18:57:26Z,2021-12-07T18:57:26Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90757', 'http://dx.doi.org/10.26153/tsw/17676']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['iterative processing', 'mechanical interface', 'hybrid additive manufacturing', 'hybrid subtractive manufacturing']",Mechanical Interface for Iterative Hybrid Additive and Subtractive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a4286668-3b59-4c24-976c-7b7b51b91ac7/download,University of Texas at Austin,"Additive and subtractive manufacturing systems for in-envelope production of large
objects face challenges with respect to reach and access of cutting tools. One approach to
overcoming this is iteratively alternate between additive and subtractive processes. However,
polymer objects require cooling before machining, resulting in poor thermal welding when the
subsequent polymer layer is deposited. This paper describes a method to enable iterative
processing for in-envelope hybrid manufacturing that uses a mechanical bond to transition back to
additive deposition after machining. This is accomplished using an AMBIT screw-extrusion head
to additively manufacture a section of the object within a 5-axis machining center. After the object
is machined, a dovetail cutting tool forms undercut geometry in the interface where plastic
extrusion will resume. Upon polymer solidification, a mechanical interlock is formed. This work
evaluates several undercut geometries for mechanical performance. This iterative approach to
hybrid additive/subtractive manufacturing reduces machining complexity while maintaining
structural integrity.",,,,,,
"['Benedetti, L.', 'Brulé, B.', 'Decraemer, N.', 'Davies, R.', 'Evans, K.', 'Ghita, O.']",2021-11-18T01:19:06Z,2021-11-18T01:19:06Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90389', 'http://dx.doi.org/10.26153/tsw/17310']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['high temperature laser sintering', 'PEKK', 'mechanical performance']",Mechanical Performance of Laser Sintered Poly(ether Ketone Ketone) (PEKK),Conference paper,https://repositories.lib.utexas.edu//bitstreams/d556d781-f86a-40fe-b725-5d0194193da5/download,University of Texas at Austin,"The recent progress in Additive Manufacturing Powder Bed Fusion systems are bound
to attract uptake of new high performance materials. Within the Poly(aryl ether ketone)
(PAEK) family, Poly(ether ketone ketone) (PEKK) shows promising mechanical properties, comparable with the commercial laser sintering grade PEK HP3, whilst processed at
significantly lower temperatures. Kepstan 6002 PEKK specimens were laser sintered in
multiple orientations and a range of mechanical tests were used to assess overall performance. PEKK showed outstanding ultimate tensile strength ranging between 75 and 90
MPa in x-y direction whilst maintaining an elongation at break of 2.6%. Further investigation of the fracture showed localized plastic regions attributed to a better performance.
The same plastic behaviour is observed during compression, in which PEKK showed remarkable deformation with no signs of breaking. The combination of properties offered
by Kepstan PEKK parts manufactured at a lower processing temperature makes it a very
attractive polymer for applications in the aerospace and automotive sectors.",,,,,,
"['Ponnusamy, P.', 'Masood, S.H.', 'Ruan, D.', 'Palanisamy, S.', 'Rahman Rashid, R.A.', 'Ahmed Mohamed, Omar']",2021-11-02T15:11:09Z,2021-11-02T15:11:09Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89824,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', '17-4 PH', 'quasi-static compression', 'microhardness', 'factorial design']",Mechanical Performance of Selective Laser Melted 17-4 PH Stainless Steel Under Compressive Loading,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f67acfb-8547-45d3-a451-4c11a6c98226/download,University of Texas at Austin,"Selective Laser Melting (SLM) is a powder-bed type Additive Manufacturing (AM)
process, where metal powder melting is followed by rapid solidification to yield metallic
components. The mechanical performance of the components is greatly influenced by various
SLM process parameters such as laser power, scan speed, scan pattern, hatch distance, build
orientation, layer thickness and defocus distance. Studies on compressive properties of stainless
steel parts by SLM have received relatively little attention. In this study, an investigation was
conducted to assess the influence of laser power, build orientation, layer thickness and laser
defocus distance on the mechanical behaviour of selective laser melted 17-4 PH stainless steel
parts under quasi-static compression. Fractional factorial design was used to optimise the four
process parameters to obtain maximum hardness and compressive strength with least porosity.
Results are supported by studies on porosity and microstructure observations.",,,,,,
"['Bens, A. T.', 'Tille, C.', 'Leukers, B.', 'Bermes, G.', 'Emons, M.', 'Sobe, R.', 'Pansky, A.', 'Roitzheim, B.', 'Schulze, M.', 'Tobiasch, E.', 'Seitz, H.']",2020-02-20T21:04:38Z,2020-02-20T21:04:38Z,8/25/05,Mechanical Engineering,,https://hdl.handle.net/2152/80054,eng,2005 International Solid Freeform Fabrication Symposium,Open,stereolithography,Mechanical Properties and Bioanalytical Characterization for a Novel Non-Toxic Flexible Photopolymer Formulation Class,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7701583d-70fc-4987-86c6-99aab3cc2509/download,,"We present herein a new class of resin formulations for stereolithography, named FlexSL,
with a broad bandwidth of tunable mechanical properties. The novel polyether(meth)acrylate
based material class has outstanding material characteristics in combination with the advantages
of being a biocompatible (meth)acrylate based processing material. FlexSL shows very promising
results in several initial biocompatibility tests. This emphasizes its non-toxic behavior in a
biomedical environment, caused mainly by the (meth)acrylate based core components. The
FlexSL materials are less cytotoxic than other commercial available and tested resin materials.
This novel resin material could then be one of the engineering materials of choice for very
complex three-dimensional structures in the medical technologies area. A short overview of
mechanical and processing properties will be given in the end.",,,,,,
"['Dalgarno, K. W.', 'Wood, D. J.', 'Goodridge, R. D.', 'Xiao, K.', 'Ohtsuki, C.', 'Genever, P.', 'Dyson, J.']",2020-02-20T20:44:01Z,2020-02-20T20:44:01Z,8/25/05,Mechanical Engineering,,https://hdl.handle.net/2152/80051,eng,2005 International Solid Freeform Fabrication Symposium,Open,"['apatite-mullite', 'apatite-wollostonite']",Mechanical Properties and Biological Responses of Bioactive Glass Ceramics Processed using Indirect SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df654d2f-6258-404a-bfa9-1e12660c1e3f/download,,"This paper will report on research which aims to generate bone replacement components by
processing bioactive glass-ceramic powders using indirect selective laser sintering. The indirect
SLS route has been chosen as it offers the ability to tailor the shape of the implant to the
implantation site, and two bioactive glass ceramic materials have been processed through this
route: apatite-mullite and apatite-wollostanite. The results of bend tests, to investigate
mechanical properties, and in vitro and in vivo experiments to investigate biological responses of
the materials will be reported, and the suitability of completed components for implant will be
assessed.",,,,,,
"['Obielodan, J.', 'Delwiche, M.']",2023-03-29T16:25:53Z,2023-03-29T16:25:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117680', 'http://dx.doi.org/10.26153/tsw/44559']",eng,2022 International Solid Freeform Fabrication Symposium,Open,laser sintering,Mechanical Properties Characterization for Polyamide Matrix Dairy Protein Composites  Fabricated Using Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f84ce460-5358-4190-85dd-d15a5b125de5/download,,"This work investigates the viability of casein protein for manufacturing engineering 
structures. Polyamide 12 (PA12) was used as a matrix for different compositions of casein up to 
20 wt%. Test samples were fabricated for neat PA12 and the composites using selective laser 
sintering for mechanical properties comparisons. The results show significant increases of the 
tensile strengths up to 71% for the composite materials over the neat PA12. Stiffnesses also 
increased up to 157%. The composite samples were embrittled in comparison with the neat PA12 
samples, however, with the addition of a plasticizer, significant improvement in ductility was 
obtained from near 2% to over 6% percent elongation with marginal loss in strength. The 
investigation shows the dependencies of mechanical properties of the composites on the type of 
filler casein and treatments.",,,,,,
"['Yan, Lei', 'Cui, Wenyuan', 'Newkirk, Joseph W.', 'Liou, Frank', 'Thomas, Eric E.', 'Baker, Andrew H.', 'Castle, James B.']",2021-11-09T15:32:58Z,2021-11-09T15:32:58Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90096', 'http://dx.doi.org/10.26153/tsw/17017']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['Ti-6Al-4V', 'thin-wall structure', 'laser metal deposition', 'CNC milling', 'hybrid manufacturing', 'design of experiment']",Mechanical Properties Evaluation of a Ti-6Al-4V Thin-Wall Structure Produced by a Hybrid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/076a2a45-d15a-40a8-9648-6e2a33e3dc84/download,University of Texas at Austin,"The hybrid manufacturing (HM) process combines the precision of computer numerical
control (CNC) and the freeform capability of additive manufacturing to expand the versatility of
advanced manufacturing. The intent of this paper is to explore the relationship between HM
processing parameters and mechanical properties of the final parts manufactured by one type of
HM process that combines laser metal deposition (LMD) and CNC milling. The design of
experiment (DOE) is implemented to explore the Ti-6Al-4V thin-wall structure fabrication process
with different HM build strategies. Vickers hardness, tensile test, and microstructure analyses are
conducted to evaluate the mechanical property variance within the final parts fabricated according
to the DOE matrix. Finally, a prediction model of yield strength at 0.2% offset for Ti-6Al-4V parts
built through the aforementioned HM process was obtained by an analysis of variance (ANOVA)
test, which revealed the significant factors are build height within each LMD process, laser energy
input, and the interaction of build height within each LMD process to the preheating condition.",,,,,,
"['Hung, Chia-Hung', 'Shen, Yiyu', 'Leu, Ming', 'Tsai, Hai-Lung']",2021-11-04T15:33:21Z,2021-11-04T15:33:21Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89987', 'http://dx.doi.org/10.26153/tsw/16908']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['mechanical property', '304L stainless steel', '304L', 'laser-foil-printing']",Mechanical Properties of 304L Metal Parts Made by Laser-Foil-Printing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9c28d9b8-fbfe-44df-85ab-22f176e0b19a/download,University of Texas at Austin,"Laser-Foil-Printing (LFP) is a novel laminated object manufacturing process for metal
additive manufacturing. It fabricates three-dimensional metal parts by using a dual-laser system
to weld and cut metal foils layer by layer. A main advantage of LFP is the higher cooling rate
compared to powder-based laser additive manufacturing processes due to the thermal
conductivity difference between foil and powder. This study focuses on the mechanical
properties of 304L stainless steel parts built by the LFP process. The experimental results
indicate that the yield strength and ultimate tensile strength of LFP fabricated 304L SS parts are
higher by 9% and 8% in the longitudinal direction, and 24% and 25% in the transverse direction,
respectively, in comparison to the parts fabricated by the selective laser melting process. X-ray
diffraction and electron backscattered diffraction are used to obtain the lattice structure and the
grain size of the fabricated parts.",,,,,,
"['Pinter, P.', 'Baumann, S.', 'Lohr, C.', 'Heuer, A.', 'Englert, L.', 'Weidenmann, K.A.']",2021-11-15T22:28:41Z,2021-11-15T22:28:41Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90295', 'http://dx.doi.org/10.26153/tsw/17216']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['APF', 'FFF', 'impact properties', 'computed tomography']",Mechanical Properties of Additively Manufactured Polymer Samples using a Piezo Controlled Injection Molding Unit and Fused Filament Fabrication compared with a Conventional Injection Molding Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/84d90199-4e35-498c-8a7d-be66379f3c9d/download,University of Texas at Austin,"In polymer additive manufacturing (AM), many processes have been developed and optimized in order to
achieve decent mechanical properties in recent years. Nonetheless, it is hardly possible to reach the reference
properties given by the injection molding process using the same base material.
Within this contribution, a process using a piezo controlled injection molding unit was compared with a common
fused filament fabrication (FFF) process and the injection molding process. The novel AM process using an
injection molding unit can theoretically process any thermoplastic granulate. In order to compare these three
mentioned processes, a filament for the FFF was extruded using the same ABS granulate as for the method based
on the piezo controlled injection molding unit and the conventional injection molding process.
Results show that quasi-static mechanical properties depend more on the achievable density than on the
manufacturing process itself while dynamic tests offer room for optimizations.",,,,,,
"['Brøtan, V.', 'Fergani, O.', 'Sørby, K.', 'Welo, T.']",2021-11-01T21:10:29Z,2021-11-01T21:10:29Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89753,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['strut size', 'stiffness', 'compressive strength', '316L', 'rhombic dodecahedron', 'lattice structures', 'additive manufacturing']",Mechanical Properties of Biocompatible 316L Steel Rhombic Dodecahedron Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7abce253-fcfc-42fe-932a-cd7d495b06be/download,University of Texas at Austin,"Additive manufactured lattice structures have the potential of enhancing many of today’s
engineered products manufactured by traditionally methods. The former provides the capability of
altering the mechanical, thermal and acoustic properties of structures through the use of lattices.
However, more investigation is needed to better understand the manufacturability and the
mechanical behavior of sandwich structures. This paper investigates the influence of strut size on
the global stiffness and the compressive strength using compression testing of sandwich structures.
Digital Image Correlation (DIC) analysis is applied to determine the local strain distribution during
the compression test. It is found that the compressive strength increases linearly with increased
lattice strut diameter. Moreover, based on DIC the maximum strains are observed in the strut
connection regions.",,,,,,
"['Wang, Zezheng', 'Runzi, Michael', 'Gilchrist, Matthew', 'Gong, Haijun']",2021-12-01T23:27:27Z,2021-12-01T23:27:27Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90655', 'http://dx.doi.org/10.26153/tsw/17574']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['PEEK', 'mechanical properties', 'fused deposition modeling']",Mechanical Properties of High-Performance Plastic Polyether-ether-ketone (PEEK) Printed by Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/232e7d0e-2db3-481f-a832-c4c6b5da59d7/download,University of Texas at Austin,"Polyether-ether-ketone (PEEK) is a high-performance thermoplastic material with high heat
resistance, high chemical resistance, high water resistance, and high wear resistance. Due to its
distinguished strength and durability, PEEK is extensively used for aerospace, automotive, and
medical applications. 3D printing PEEK filaments offer a new approach to make PEEK parts, fulfilling specific requirements of geometrical complexity. But the mechanical properties of 3D
printed PEEK materials are not further explored. This study investigated the mechanical
properties of PEEK materials fabricated using the fused deposition modeling (FDM) 3D printing
process. Tensile test, hardness test, and impact test were conducted to the PEEK samples, in
compliance with ASTM standards. The testing results were summarized and discussed, compared to the conventionally manufactured PEEK materials. This study also provides insights
on employing FDM 3D printing process for making PEEK parts, based on its special mechanical
properties and failure mode.",,,,,,
"['Bandyopadhyay, Amit', 'Atisivan, Raj', 'Kuhn, Gabe', 'Yeruva, Suresh']",2019-09-18T16:07:37Z,2019-09-18T16:07:37Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75897', 'http://dx.doi.org/10.26153/tsw/2997']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Alumina-Al,Mechanical Properties of Interconnected Phase Alumina-Al Composites 24,Conference paper,https://repositories.lib.utexas.edu//bitstreams/418b02f4-bff1-454b-af44-819cddeccd03/download,,"Interconnected phase alumina-Al composites were fabricated by pressureless reactive
metal infiltration of porous mullite ceramic preforms. Controlled porosity mullite
ceramics were processed via the indirect fused deposition. Volume fraction, size and
distribution of metals were varied in the composite to understand their effects on
physical, thermal and mechanical properties. Mechanical testes were conducted
under uniaxial compression and four-point bend loading. Fractographic analyses of
these samples were performed to understand the mechanism of failure under different
types of loading. The paper describes processing and characterization of structured
alumina-Al composites.",Office of Naval Research through the grant N00014-98-1-550 (Program Manager: Dr. Steve Fishman).,,,,,
"['Kobryn, P.A.', 'Semiatin, S.L.']",2019-10-10T16:54:21Z,2019-10-10T16:54:21Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76172', 'http://dx.doi.org/10.26153/tsw/3261']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Laser-Deposited,Mechanical Properties of Laser-Deposited Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1f223781-6661-4c46-bce0-e2fdafc56f01/download,,"Laser additive manufacturing is a solid-freeform-fabrication process which is being
investigated for titanium-component manufacturing and repair based on its cost-reduction
potential and flexibility. Laser additive manufacturing also has the potential to improve
mechanical properties due to the high cooling rates involved. However, the effect of the layered
manufacturing process and any lack-of-fusion porosity and texture on the magnitude and
anisotropy of mechanical properties is of concern. Hence, a preliminary effort was undertaken to
assess these effects for bulk Ti-6Al-4V deposits manufactured using the LENS™ process.
Tension, fatigue, and crack-growth tests were performed on both stress-relieved and HIP’ed
deposits in three primary directions. The results were compared to published data for
conventionally processed Ti-6Al-4V castings and forgings.",,,,,,
"['Santos, Edson', 'Abe, F.', 'Kitamura, Y.', 'Osakada, K.', 'Shiomi, M.']",2019-10-23T14:30:23Z,2019-10-23T14:30:23Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76547', 'http://dx.doi.org/10.26153/tsw/3636']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Titanium,Mechanical Properties of Pure Titanium Models Processed by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2cd12e5e-560f-4ac6-abfd-fa7436e4b592/download,,"The influence of laser processing parameters on mechanical properties and microstructure
of pure titanium models made by selective laser melting is investigated. The density of the
models can reach higher than 95% under proper conditions. Although the tensile strength test
shows results comparable to the wrought material, the impact and torsional fatigue strengths are
low because of porosity and oxygen pick-up suggested by increasing of hardness. Hot isostatic
pressing allows almost full densification and greatly improves mechanical properties.",,,,,,
"['Aboulkhair, Nesma T.', 'Stephens, Alex', 'Maskery, Ian', 'Tuck, Chris', 'Ashcroft, Ian', 'Everitt, Nicola M.']",2021-10-21T15:34:14Z,2021-10-21T15:34:14Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89398,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'aluminum alloys', 'AlSi10Mg', 'nanoscale', 'microscale', 'macroscale', 'mechanical properties']","Mechanical Properties of Selective Laser Melted AlSi10Mg: Nano, Micro, and Macro Properties",Conference paper,https://repositories.lib.utexas.edu//bitstreams/4f3cb635-ea27-4afa-b824-b80260674721/download,University of Texas at Austin,"The selective laser melting (SLM) of aluminium alloys is of great current interest at both
the industrial and research levels. Aluminium poses a challenge to SLM compared with other
candidate materials, such as titanium alloys, stainless steels, and nickel-based alloys, because of
its high thermal diffusivity and low infrared absorptivity and tendency to result in relatively
porous parts. However, recent studies have reported the successful production of dense
AlSi10Mg parts using SLM. In this study, we report on the nano, micro, and macroscopic
mechanical properties of dense AlSi10Mg samples fabricated by SLM. Nanoindentation revealed
the hardness profile across individual melt pools building up the parts to be uniform. This is due
to the fine microstructure and uniform chemical elements distribution developed during the
process due to rapid solidification. Micro-hardness testing showed anisotropy in properties
according to the build orientation driven by the texture produced during solidification. Lastly, the
tensile and compressive behaviours of the parts were examined showing high strength under both
loading conditions as well as adequate amounts of strain. These superior mechanical properties
compared to those achieved via conventional manufacturing promote SLM as promising for
several applications.",,,,,,
"['Li, Yingqi', 'Leu, Ming C.', 'Tsai, Hai-Lung']",2021-11-11T15:25:38Z,2021-11-11T15:25:38Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90219', 'http://dx.doi.org/10.26153/tsw/17140']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['metallic glass', 'laser processing', 'additive manufacturing', 'mechanical properties']",Mechanical Properties of Zr-Based Bulk Metallic Glass Parts Fabricated by Laser-Foil-Printing Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc9f5a39-0fa5-4d18-a8f7-72f4216d1e6e/download,University of Texas at Austin,"The application of bulk metallic glasses (BMGs) has been traditionally limited to parts with small
dimensions and simple geometries, due to the requirement of fast cooling during the conventional process of
casting. This research exemplifies a promising additive manufacturing method, i.e., laser-foil-printing (LFP), to
fabricate high-quality BMG parts with large dimensions and complex geometries. In this study,
Zr52.5Ti5Al10Ni14.6Cu17.9 BMG parts were fabricated by LFP technology in which MG foils are laser welded layer-by-layer upon a substrate. The mechanical properties of the fabricated BMG parts were measured using micro-indentation, tensile test and four-point bending test, and then compared to as-cast BMG parts. Through LFP, as
rapid cooling rates can be achieved, fully amorphous and nearly fully dense BMG parts without cracking have
been successfully made. The fabricated BMG parts exhibit mechanical properties, including micro-hardness,
tensile strength, and flexural strength, comparable with the as-cast BMG parts.",,,,,,
"['Snarr, Scott E.', 'Beaman, Joseph J. Jr', 'Fish, Scott']",2021-11-10T21:44:27Z,2021-11-10T21:44:27Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90186', 'http://dx.doi.org/10.26153/tsw/17107']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['parameter development', 'set point development', 'laser parameter', 'set point', 'selective laser sintering', 'carbon fiber reinforced polyetheretherketone', 'CFR PEEK']",Mechanical Property Correlation and Laser Parameter Development for the Selective Laser Sintering of Carbon Fiber Reinforced Polyetheretherketone,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a81ead32-4ca1-43c1-a609-c6be3d05d663/download,University of Texas at Austin,,,"This thesis specifically investigates parameter and set point development for a material novel to the
SLS process, Carbon Fiber Reinforced Polyetheretherketone (CFR PEEK).",,,,
"['Khalid Rafi, H.', 'Karthik, N.V.', 'Starr, Thomas L.', 'Stucker, Brent E.']",2021-10-06T20:27:44Z,2021-10-06T20:27:44Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88434', 'http://dx.doi.org/10.26153/tsw/15371']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Ti-6Al-4V', 'electron beam melting', 'mechanical properties']",Mechanical Property Evaluation of Ti-6Al-4V Parts Made Using Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/051d1544-3fd3-464a-bc15-7b8455f6a6a8/download,University of Texas at Austin,"Cylindrical Ti-6Al-4V parts were built in vertical and horizontal orientations using
electron beam melting. Tensile tests and fatigue tests were carried out. The specimens were
tested in as-built and machined conditions to understand the effect of surface finish on
mechanical properties. The fracture surfaces were analyzed using scanning electron microscopy
and the fractography results were correlated with the mechanical properties. Based on the results
the effects of part orientation and surface finish on mechanical properties are discussed.",,,,,,
"['Dietrich, S.', 'Karcher, B.', 'Popp, U.', 'Scholz, J.']",2024-03-27T15:52:45Z,2024-03-27T15:52:45Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124492', 'https://doi.org/10.26153/tsw/51100']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['fused filament fabrication', 'material extrusion', 'surface treatment', 'polymer']",Mechanical Surface Treatment of Polymer Parts Produced by FFF,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e714423b-107c-4952-8eac-26b6e4bf94a5/download,University of Texas at Austin,"The surface structure in the form of waviness and roughness as well as near surface density of FFF parts
represents a major issue with respect to mechanical performance especially under fatigue loading. Mechanical
surface treatments like shot peening or rolling are commonly used techniques, especially for metal components,
to reduce surface roughness, increase surface densification and create beneficial residual stress states in the
surface layer. In this study, a rolling process has been applied intermittently with the layer-wise FFF process and
the effect on the surface state has been investigated using laser scanning and optical microscopy as well as microcomputed tomography. A process window with different rolling tools and rolling paths has been identified
and analysed. The results show clearly advantageous properties regarding an improved surface roughness,
with a higher densification gradient in the first perimeter tracks of the FFF extrusion strategy as well as sharper
corners being realized.",,,,,,
"['Dongare, Suijitkumar', 'Sparks, Todd E.', 'Newkirk, Joseph', 'Liou, Frank']",2021-10-12T21:31:17Z,2021-10-12T21:31:17Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88745', 'http://dx.doi.org/10.26153/tsw/15679']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'mini-tensile', 'mini-tensile testing', 'tensile properties']",A Mechanical Testing Methodology for Metal Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7c7d22a9-ab67-45f8-b6cb-e3b61282b90a/download,University of Texas at Austin,"Most additive manufacturing processes are layer-by-layer deposition, thus its mechanical
properties could be very different than those made from traditional manufacturing processes.
This paper summarizes a mini-tensile testing methodology for additive manufacturing. Research
concerning the tensile testing of metallic material has been conducted and test methods have
been defined. It encompasses the methods for determination of yield strength, yield point
elongation, tensile strength, elongation, and reduction of area. The study of positional variation
and cooling-rate dependency in case of additive manufacturing proves to be expensive and time
consuming with the full-size test specimens. Thus, this paper discussed a technique for testing of
tensile properties using miniature sized test specimens. It covers detailed procedures for
development of test specimens, actual testing set-up and the analysis of test results.",,,,,,
"['Weflen, E.D.', 'Peters, F.E.', 'Frank, M.C.']",2024-03-26T21:30:14Z,2024-03-26T21:30:14Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124418', 'https://doi.org/10.26153/tsw/51026']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['big area additive manufacturing', 'print surface', 'additive manufacturing']",MECHANICALLY BONDING AND THERMALLY RELEASING PRINT SURFACE FOR BIG AREA ADDITIVE MANUFACTURING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83a07885-a65b-4af2-afb3-d6e0d61b037e/download,University of Texas at Austin,"Part retention and removal are challenges for Big Area Additive Manufacturing (BAAM)
systems, increasing production costs and impacting part quality. A part should remain locked to
the print surface during processing and then be released for removal when processing is completed.
However, a method for releasing large, multi-meter parts from the print surface on BAAM systems
is nonexistent. This work presents a print surface with a mechanically bonding interfacial structure
that locks the part to the print surface during processing and then thermally releases the part for
removal. Design and process parameters were evaluated, and a model was developed as a design
guide for industry implementation. A demonstration casting pattern was produced in a hybrid
manufacturing machining center by iterating between polymer pellet-fed material extrusion and
surface machining. The viable applications of BAAM can be expanded by improving the process
and reducing costs.",,,,,,
"['Ramos, Jorge', 'Bourell, David']",2019-11-21T18:28:43Z,2019-11-21T18:28:43Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78560', 'http://dx.doi.org/10.26153/tsw/5616']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Surface Interaction,Mechanics of the Selective Laser Raster-Scanning Surface Interaction,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43516d5d-52bf-4600-a557-59751b7871d9/download,,"In recent years, the use of a high power laser beam actuated by fast speed
scanning mirrors has opened up novel selective laser raster-scan processing venues as
extremely rapid motion and high overlapping of the beam can be attained. This permits
distribution of laser energy precisely over geometric patterns such as rectangles, circles,
triangles etc. The surface thermal history at any given point under such processing was
estimated using an analytical solution for the 1D, semi-infinite, surface flux boundary
condition heat conduction problem together with linear superposition theory. Presented
here is the comparison of the thermal histories of different selective laser surface
processes previously implemented, namely: laser surface polishing of flat surfaces, laser
induced cementation of cylindrical surfaces and direct laser single layer masked
deposition. It was possible to verify that in laser induced cementation, long-width and
short-length scanned regions provided low average temperature and low heating rate with
spaced out temperature peaks, whereas for direct laser single layer deposition in which a
narrow-width – long-length region is scanned, the heating rate and peak temperature are
higher and the peaks are squeezed. The analysis also provided ways to estimate the
Andrew’s number associated with a raster-scan process for the sake of comparison with
single-beam processes having a given number value. Understanding the influence of scan
geometry and overlapping on the selective raster-scan processing provides a method to
tailor the surface peak temperature as well as the heating and cooling rates, affecting the
solidification or sintering conditions and therefore the mechanical properties of the parts
obtained.",,,,,,
"['Dwivedi, Rajeev', 'Zekovic, Srdja', 'Kovacevic, Radovan']",2020-02-24T14:25:29Z,2020-02-24T14:25:29Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80074', 'http://dx.doi.org/10.26153/tsw/7095']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Mechanism for Determination of G-factors for Solid Freeform Fabrication Techniques Based on Large Heat Input,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e2d87489-6368-435c-82af-456a491b4fca/download,,"A major class of Solid Freeform Fabrication (SFF) methods for metal deposition
are based on large heat input. The geometry and microstructural properties of the
deposition depend primarily on the heat input and the subsequent distribution at
the substrate. On one hand the insufficient heat may lead to the inadequate melting
of the metal, on the other hand overheating and heat accumulation leads to the overmelting, resulting in the deformation of the build up geometry. The heat distribution is
governed by the available heat sink . For a better control of the process, the estimation
of heat sinks and the subsequent control of the energy input allows a better control
of the process. A parameter G-factor that estimates the heat sink based on the local
geometry of a part has been introduced. The estimation of G-factor is based on the
simulation and the experimental results. Also a mechanism to determine the G-factor
for various substrate geometries has been introduced.",,,,,,
"['Nussbaum, J.', 'Crane, N.B.']",2021-10-12T20:15:51Z,2021-10-12T20:15:51Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88731', 'http://dx.doi.org/10.26153/tsw/15665']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['post processing deformation', 'additive manufacturing', 'selective heating', 'multimaterial fabrication', 'selective deformation']",Mechanisms for Post Processing Deformation without Part-Specific Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3acfbb8d-9345-43d7-90e7-39134e8c8de0/download,University of Texas at Austin,"Post processing deformation of additive manufactured components offers many advantages
from reduced printing time and material usage to simplified multimaterial fabrication. For
thermoplastic components, controlled deformations can be achieved by locally heating to
temporarily soften the material. This paper investigates multiple methods of selectively heating
and deforming desired locations to form the final component. The deformation location can be
controlled by geometry (thickness), surface properties (reflectivity) or by local addition of a
secondary material to control the heating. Demonstrations are provided for each of these
deformation methods and then an example is provided to show how this approach could produce
customized geometries from a standard feature.",,,,,,
"['Gong, Haijun', 'Gu, Hengfeng', 'Zeng, Kai', 'Dilip, J.J.S.', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-12T21:42:50Z,2021-10-12T21:42:50Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88748', 'http://dx.doi.org/10.26153/tsw/15682']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'pre-alloyed powder', 'Ti-6Al-4V', 'parameter optimization', 'single bead fabrication', 'melt', 'melt pool geometry']",Melt Pool Characterization for Selective Laser Melting of Ti-6Al-4V Pre-alloyed Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5f2b2be-36f6-4b50-aa11-a0e6b9b214f2/download,University of Texas at Austin,"Parameter optimization for metal powders in Selective Laser Melting (SLM) is usually
carried out by experimental investigations of the influence of significant parameters (such as laser
power, scan speed, hatch spacing, layer thickness, scan pattern, etc.) on microstructure and/or
mechanical properties. This type of experimental optimization is extremely time- and cost-consuming. In order to accelerate the optimization process, a study was undertaken to develop a
method for rapid optimization of parameters based on melt pool characterizations. These
characterizations began with investigations of SLM single bead experiments. Pre-alloyed Ti-6Al-4V powder was used for single bead fabrication with multiple laser power and scan speed
combinations. Surface morphology and dimensions of single beads were characterized.
Geometrical features of melt pools were measured after polishing and etching of the cross section
of each single bead. It was found that melt pool characteristics provide significant information that
is helpful for process parameters selection. These experiments are being extended to characterize
test pads with multiple layers.",,,,,,
"['Cheng, Bo', 'Lydon, James', 'Cooper, Kenneth', 'Cole, Vernon', 'Northrop, Paul', 'Chou, Kevin']",2021-11-03T21:46:48Z,2021-11-03T21:46:48Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89942,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'SLM', 'infrared imaging', 'melt pool size']",Melt Pool Dimension Measurement in Selective Laser Melting Using Thermal Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e83de706-0558-4a39-8d0d-ec07d24bddcf/download,University of Texas at Austin,"Process temperature measurement for selective laser melting (SLM) can provide critical
information such as melt pool dimension for real-time part quality control. In this study, a MCS640
LumaSense thermal imager was utilized to collect process radiant temperature information during
SLM fabrication using Inconel718 powder. Identified liquidus-solidus transition was used to
calculate melt pool size. Speed effect on melt pool dimension has been investigated. The major
findings are as follows. (1) At a beam power of 180 W, the averaged melt pool has dimensions of
about 0.39 mm and 0.23 mm in length and width for 400 mm/s scanning speed. (2) No significant
difference has been observed for melt pool size at different build height for a given scanning speed.
(3) Melt pool width decreases with the increase of scanning speed, while similar melt pool length
was observed at different speed under a laser power of 180 W.",,,,,,
"['Cheng, Bo', 'Chou, Kevin']",2021-10-21T17:53:57Z,2021-10-21T17:53:57Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89410,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'raster scan', 'finite element method', 'remelting']",Melt Pool Evolution Study in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78c63eff-d72e-4f06-9bef-007429c512f4/download,University of Texas at Austin,"In selective laser melting (SLM) additive manufacturing, the completion of the entire
scanning cross-sectional area of each layer build is consisted of many smaller scanning patches.
Hence, the scanning length in each path may be too short to reach the melt pool quasi-steady
state, thus, affecting the melt pool geometry, which is also effected by the process parameters. It
is also known that the melt pool size correlates with the build part microstructures and properties.
In this study, temperature simulations, finite-element based, of SLM for In718 is applied to track
the thermal response during scanning of an individual patch. The results show that the process
parameters determine the melt pool evolution, which affects the actual molten pool size in the
regions defined by the raster scanning length. Manipulating the scanning path length and process
parameters, based on the melt pool evolution information, may help to achieve a desired melt
pool size for part quality controls.",,,,,,
"['Park, Bumsoo', 'Wang, Xin', 'Mishra, Sandipan', 'Bristow, Douglas', 'Landers, Robert']",2023-01-27T13:48:46Z,2023-01-27T13:48:46Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117331', 'http://dx.doi.org/10.26153/tsw/44212']",eng,2022 International Solid Freeform Fabrication Symposium,Open,powder bed fusion,"Melt Pool Feature Extraction, Spatial Registration, and Layer-To-Layer Control in Powder Bed Fusion",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b26e8da3-325a-4e28-91ab-a9386c704332/download,,"Laser Powder Bed Fusion (LPBF) is a well-known additive manufacturing technique that uses a high-
power laser to fuse loose metal powder into a solid part. A major issue restricting this technology from wider 
industrial applications is the lack of part quality assurance. In this paper, a high-speed (2kHz) co-axial near-
infrared optical camera setup is implemented for process monitoring and control. The acquisition locations for 
individual images are estimated based on specified scan paths and scan velocities to create a spatial registration 
technique. Melt pool thermal features are linked to specific locations instead of time instants, motivating a spatial 
control strategy to achieve thermal feature uniformity. Based on the spatial mapping of the thermal features, 
experimental studies are conducted where a spatial layer-to-layer iterative learning controller is implemented to 
achieve spatial uniformity of the thermal features. The experimental results present a convergence of the thermal 
features to a uniform level.",,,,,,
"['Cheng, Bo', 'Chou, Kevin']",2021-10-11T21:49:05Z,2021-10-11T21:49:05Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88655', 'http://dx.doi.org/10.26153/tsw/15589']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['design of experiments', 'electron beam additive manufacturing', 'melt pool geometry', 'process parameters', 'thermal modeling']",Melt Pool Geometry Simulations for Powder-Based Electron Beam Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b6f3c78-0e0c-4e92-b37c-7da0f666509e/download,University of Texas at Austin,"It is known that the melt pool geometry and dynamics strongly affect the build
part properties in metal-based additive manufacturing (AM) processes. Thus, process
temperature predictions may offer useful information of the melt pool evolution during
the heating-cooling cycle. A transient thermal modeling for powder-based electron beam
additive manufacturing (EBAM) process has been developed for process temperature
simulations, considering temperature and porosity dependent thermal properties. In this
study, the thermal model is applied to evaluate, for the case of Ti-6Al-4V in EBAM, the
process parameter effects, such as the beam speed, on the temperature profile along the
melt scan and the corresponding melt pool geometric characteristics such as the lengthdepth ratio and the cross-sectional area. The intent is to establish a process envelop for
part quality control.",,,,,,
"['Sampson, R.', 'Lancaster, R.', 'Weston, M.']",2021-11-04T14:06:30Z,2021-11-04T14:06:30Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89964,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['image process acceleration', 'image processing', 'melt pool', 'General Purpose', 'Graphics Processing Units', 'direct energy deposition']",Melt Pool Image Process Acceleration Using General Purpose Computing on Graphics Processing Units,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e6935e2b-6840-4f34-b9fd-158cf3c51310/download,University of Texas at Austin,"The additive manufacturing (AM) process is incredibly complex, and the intricate web of changing process parameters can result in poor repeatability and structural consistency. New geometric designs result in an initial iteration process to optimise build parameters, which is highly
laborious and time consuming. A deep understanding of process parameters in AM, and the
ability to control and manipulate said parameters, may lead to advanced AM capabilities.
Non-contact devices are typically required to measure the build characteristics such as melt
pool geometry and temperature, which give a greater understanding of the complex AM process. This paper will look to view the molten metal pool that is formed in the Direct Energy
Deposition (DED) process using complementary metal-oxide-semiconductor (CMOS) cameras
and presents a new method of using General Purpose computing on Graphics Processing Units
(GPGPU) to accelerate the image processing technique for such applications.",,,,,,
"['Gibson, B.T.', 'Bandari, Y.K.', 'Richardson, B.S.', 'Roschli, A.C.', 'Post, B.K.', 'Borish, M.C.', 'Thornton, A.', 'Henry, W.C.', 'Lamsey, M.', 'Love, L.J.']",2021-11-18T18:06:47Z,2021-11-18T18:06:47Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90450', 'http://dx.doi.org/10.26153/tsw/17371']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['melt pool monitoring', 'large scale metal additive manufacturing', 'laser-wire based directed energy  deposition', 'Oak Ridge National Laboratory', 'GKN Aerospace']",Melt Pool Monitoring for Control and Data Analytics in Large-Scale Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f01edcc5-ce0a-482b-9ea6-8388aafebaf0/download,University of Texas at Austin,"Laser-wire based Directed Energy Deposition (DED) processes are being developed at Oak
Ridge National Laboratory’s Manufacturing Demonstration Facility, in collaboration with GKN
Aerospace, for large volume metal additive manufacturing of metallic structures. The technology
has the potential to deliver reduced costs and lead times when compared to conventional methods
of manufacturing in several industries. While complex structures are being produced with
relatively high deposition rates and at near-net shape, issues persist with achieving consistent
geometric accuracy and thermal stability. A significant research effort is focused on developing
coordinated, multi-modal sensing and control for addressing these issues. An introduction to this
large-volume metal process will be provided, followed by investigations into real-time thermal
monitoring capabilities that support control and data analytics frameworks. Studies focused on
melt pool monitoring via infrared thermography, thermal and geometric effects on melt pool size
measurement, and interactions between process variables and thermal monitoring metrics are
presented.",,,,,,
"['Aggarangsi, Pruk', 'Beuth, Jack L.', 'Griffith, Michelle']",2019-11-20T16:13:25Z,2019-11-20T16:13:25Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78468', 'http://dx.doi.org/10.26153/tsw/5553']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Laser-Based Deposition,Melt Pool Size and Stress Control for Laser-Based Deposition Near a Free Edge,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6537b774-f88d-4cb2-88fd-cf399e166304/download,,"Thermomechanical models developed in this research address two experimental
observations made during the deposition of thin-walled structures by the LENSTM process. The
first observation (via thermal imaging) is of substantial increases in melt pool size as a vertical
free edge is approached under conditions of constant laser power and velocity. The second
observation (via neutron diffraction) is of large tensile stresses in the vertical direction at vertical
free edges, after deposition is completed and the wall is allowed to cool to room temperature. At
issue is how to best control melt pool size as a free edge is approached and whether such control
will also reduce observed free edge stresses. Thermomechanical model results are presented
which demonstrate that power reduction curves suggested by process maps for melt pool size
under steady-state conditions can be effective in controlling melt pool size as a free edge is
approached. However, to achieve optimal results it is important that power reductions be
initiated before increases in melt pool size are observed. Stress simulations indicate that control
of melt pool size can reduce free-edge stresses; however, the primary cause of these stresses is a
constraint effect which is independent of melt pool size.","This research was supported by the National Science Foundation Division of Design,
Manufacture and Industrial Innovation, through the Materials Processing and Manufacturing
Program, award number DMI-0200270.",,,,,
"['Vasinonta, Aditad', 'Beuth, Jack L.', 'Ong, Raymond']",2019-10-18T16:08:43Z,2019-10-18T16:08:43Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76248', 'http://dx.doi.org/10.26153/tsw/3337']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Thin-Walled,Melt Pool Size Control in Thin-Walled and Bulky Parts via Process Maps,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fd62660-b1b1-4c55-bdaf-79a71aa008bd/download,,"Control of melt pool size is critical for maintaining consistent build conditions in the
solid freeform fabrication of complex shapes. In this research, melt pool size in laser-based
solid freeform fabrication processes is studied for both thin-walled structures and bulky parts.
Numerical simulations are used to construct non-dimensional plots (termed process maps) that
quantify the effects of changes in part height, laser power, deposition speed and part preheating
on melt pool size. Strategies for the control of melt pool size suggested by the process maps are
similar for the two geometries. Insights are given as to how transitions between these two
extremes in geometry can be managed to maintain a consistent melt pool size. This modeling
work is being performed in tandem with process development and melt pool imaging and control
research underway on the LENS process at Sandia National Laboratories",This research has been supported by the National Science Foundation under grant DMI9700320 and by Sandia National Laboratories under grant BE-0792.,,,,,
"['Patel, S.', 'Vlasea, M.L.']",2021-11-18T17:08:01Z,2021-11-18T17:08:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90431', 'http://dx.doi.org/10.26153/tsw/17352']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['process parameter', 'temperature prediction', 'melting mode thresholds', 'laser powder bed fusion']",Melting Mode Thresholds in Laser Powder Bed Fusion and Their Application Towards Process Parameter Development,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c73ac52d-dc19-4bd0-a551-f2af205e712c/download,University of Texas at Austin,"Depending on processing conditions, laser powder bed fusion (LPBF) has broadly two different
processing regimes, conduction and keyhole mode. Heat conduction governs the melt pool morphology observed
in conduction mode melting. In contrast, keyhole mode melting is observed when the morphology of the molten
pool is controlled by thermo-capillary convection and recoil momentum pressure generated by vaporization of a
given material. Additionally, there exists another melting mode called transition mode wherein the dominance of
conduction or convection depends on processing conditions. In this work, we use an analytical temperature
prediction model, along with normalized processing diagrams, to obtain a processing window for achieving highdensity three-dimensional Ti-6Al-4V parts on a continuous beam exposure LPBF system. The normalized
processing diagrams in this work help visualize the three melting modes - conduction, transition, and keyhole
mode. The temperature prediction model can be used to predict the thresholds between the three melting modes.
This work can be used for understanding the physical origins of defects in three-dimensional LPBF parts, as well
as lower the risk of costly experimentation to go from powder to near fully dense products.",,,,,,
"['Choi, S. H.', 'Kwok, K. T.']",2019-03-12T16:06:11Z,2019-03-12T16:06:11Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73593', 'http://dx.doi.org/10.26153/tsw/735']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'CAD']",A Memory Efficient Slicing Algorithm for Large STL Files,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ad7238eb-9717-402d-ba5f-87154bebe67c/download,,"This paper proposes a memory efficient slicing algorithm for Rapid Prototyping (RP)
processes. The algorithm is aimed to overcome the constraints of computer memory inherent in
the .conventional slicing methodologies.lte~tracts from the Stereolithography (STL) file the
facets that intersect with the cutting plane to process the slice data and the topological
information. Reading onlythefacets ofthe current layer greatly reducestheatnount ofcomputer
memory required <and involves less •computationally intensive. searching operations. Th~s, large
SThfiles>of virtually~nlimitedsizescan be sliced to facilitate theRt> process. The algorithm is
alsorelativelyfau;lt-tolerant in that inconsistent contour due to defects of the STL file may be
l11()reeffectiVelyrepaired.
The topologicaLinformation of the layer contours can be subsequel1tlyprocessed by further
operations, such as hatching, physical fabrication or virtual simulation. To cater for the variations
of RP processes, the Common Layer Interface (CLI) format is adopted as the output interface.",,,,,,
"['Park, Byong-Ho', 'Prinz, Fritz B.']",2019-09-23T15:30:27Z,2019-09-23T15:30:27Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75937', 'http://dx.doi.org/10.26153/tsw/3036']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Assemblies,Mesoscopic Assemblies with SDM Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5f6aed92-7d46-4e79-aa2d-6af56ece64bc/download,,"Shape Deposition Manufacturing (SDM) is a layered manufacturing process capable of building complex 3D parts through the combination of material addition and subtraction. Overhangs can be built with the help of sacrificial support materials. SDM achieves high surface quality by taking advantage of material subtraction by CNC machining. High surface quality in turn enables the fabrication of pre-assembled mechanisms that can be freed to turn or slide after removal of sacrificial support materials. Using SDM, miniature trailing-edge effectors (MiTEs), which are pneumatic actuators with the minimum feature size of about 500 P  KDYH EHHQ fabricated for aeroelastic control of uninhabited air vehicles (UAV’s). However, as part size is VFDOHGGRZQ OLPLWLQJSURFHVVLQJFRQVWUDLQWVZHUHREVHUYHG 7RGDWHFOHDUDQFHVRI   PFRXOG be achieved in MiTEs. Also, this paper will discuss limiting manufacturing constraints and planning issues unique to the size range which is frequently referred to as the ‘mesoscopic’ regime.",,,,,,
"['Shrestha, Subin', 'Chou, Kevin']",2021-11-03T21:28:19Z,2021-11-03T21:28:19Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89937,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['powder distribution', 'selective laser melting', 'thermo-fluid model']",Mesoscopic Multilayer Simulation of Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/62998607-e229-4011-8b15-5defe25954fb/download,University of Texas at Austin,"Selective Laser Melting (SLM) is a metal additive manufacturing with complex process physics
that requires understanding of metallic particle accumulations and interactions to layer additions.
In this work, a mesoscopic multilayer numerical model with volume of fluid (VOF) method is
developed using ANSYS/FLUENT. At first, a sequential powder adding algorithm is applied to
generate a layer of randomly distributed particles of non-uniform sizes over a solid substrate. A
moving volumetric heat source is then applied to melt a single track in the powder layer which is
defined by specifying temperature dependent material properties. After the single scan in the first
layer is completed, the surface data is acquired to re-apply sequential powder adding algorithm
over the deformed surface to generate second layer of powder. In this study, the melt flow has
been simplified and is driven primarily by constant surface tension applied over the melt pool.
The obtained track width from simulations is in reasonable agreement with experimental results
in literature.",,,,,,
"['Lee, Y.S.', 'Zhang, W.']",2021-10-21T17:10:03Z,2021-10-21T17:10:03Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89408,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['particle size distribution', 'additive manufacturing', 'volume of fluid', 'powder bed fusion']",Mesoscopic Simulation of Heat Transfer and Fluid Flow in Laser Powder Bed Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3516540e-ffc0-4f11-884a-943f56ac3669/download,University of Texas at Austin,"Laser-powder bed fusion (L-PBF) additive manufacturing involves complex physics such
as heat transfer and molten metal flow, which have a significant influence on the final build quality.
In this study, transport phenomena based modeling is used to provide a quantitative understanding
of complex molten pool transients. In particular, a three dimensional (3D), transient numerical
model is developed for L-PBF additive manufacturing by solving the governing partial differential
equations of mass, momentum and energy conservation. The individual powder particles are
resolved using the volume of fluid method (VOF) method with a fine mesh size of 3 μm (thus at
meso-scale). The powder particle arrangement including particle size distribution and packing
density are taken into account in placement of individual particles calculated using discrete
element method. Moreover, the model considers Marangoni shear stress, an important driving
force for molten metal flow. The numerical model is used to quantitatively study the effect of laser
power, scanning speed, and powder size distribution on the bead geometry and formation of balling
defect.",,,,,,
"['Vendra, L.', 'Achanta, A.']",2021-11-09T18:43:44Z,2021-11-09T18:43:44Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90114', 'http://dx.doi.org/10.26153/tsw/17035']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['metal additive manufacturing', 'additive manufacturing', 'oil industry', 'gas industry']",Metal Additive Manufacturing in the Oil and Gas Industry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/716250ad-ce25-4c2c-b70c-5a62f4105c17/download,University of Texas at Austin,"Additive Manufacturing (AM) has gained increasing prominence and had the most
significant commercial impact in the aerospace sector in the last few years. The adoption of AM
in the oil and gas industry has been slow, although the potential economic benefits it offers are
tremendous. Improving product performance, reducing costs and lead time, creating a more
flexible and distributed supply chain are some of the major focus areas for the oil and gas industry
today which cannot be attained through traditional manufacturing methods. A broad overview of
the state of Metal AM pertaining to oil and gas applications is provided. Potential applications of
AM in the oilfield are highlighted, including demonstrated examples such as components for
downhole logging and drilling tools, turbomachinery, pipeline components, etc. A lack of
qualification and certification methodologies, along with technical and cultural challenges that
hamper AM’s adoption in the industry are discussed.",,,,,,
"['Liu, Z. E.', 'Wei, P.', 'Kernan, B.', 'Heuer, A. H.', 'Cawle, J. D.']",2018-11-14T20:00:00Z,2018-11-14T20:00:00Z,1996,Mechanical Engineering,doi:10.15781/T2SB3XJ3K,http://hdl.handle.net/2152/70260,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAM-LEM', 'sheet feedstocks', 'microstructure']",Metal and Ceramic Components made via CAM-LEM Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/31760035-0c9d-4bc6-902c-95c4687c94a3/download,,"CAM-LEM (Computer-Aided Manufacturing ofLaminated Engineering Materials) is
an SFF technology suitable for many engineering materials for which feedstock is available in
sheet form; lamination and post-processing procedures are materials specific. Two methods for
producing sheetstock, tapecasting and compression molding , are discussed and contrasted.
Ceramic and metallic components that have been produced via CAM-LEM are described.",,,,,,
"['Himmer, Thomas', 'Techel, Anja', 'Nowotny, Steffen', 'Beyer, Eckhard']",2020-02-13T20:02:46Z,2020-02-13T20:02:46Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79972', 'http://dx.doi.org/10.26153/tsw/6997']",eng,2004 International Solid Freeform Fabrication Symposium,Open,fast manufacturing,Metal Laminated Tooling - A Quick and Flexible Tooling Concept,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c23791d5-893d-4e84-9789-aea03b13ae9e/download,,,,"For the fast manufacturing of complex formed tools Fraunhofer IWS works together with partners from the industry on a constant automation solution for cutting, packaging and adding steel sheet cutouts. With the selection of the most suitable connecting technology, also requirements must be considered to quality, surface quality and the production costs. Deep drawing or stamping tools do not require a complete connection of the single metal sheets. Here, a fast and economical connection is the main objective. Due to simple automation, laser beam welding offers itself as joining process. On the other hand, a temperature-steady connection of the sheet metal lamellas is necessary for injection molds, which can resist the injection pressures.",,,,
"['Badrinarayan, B.', 'Barlow, J.W.']",2018-04-19T17:34:50Z,2018-04-19T17:34:50Z,1992,Mechanical Engineering,doi:10.15781/T2988346K,http://hdl.handle.net/2152/64391,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'Electric Discharge Machining', 'PMMA']",Metal Parts From Selective Laser Sintering of Metal-Polymer Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c64bf3a6-31e0-4d3a-926e-23bb362bd674/download,,,,,,,,
"['Michaels, Steven', 'Sachs, Emanuel M.', 'Cima, Michael J.']",2018-04-19T18:23:52Z,2018-04-19T18:23:52Z,1992,Mechanical Engineering,doi:10.15781/T2GT5FZ5X,http://hdl.handle.net/2152/64405,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Three Dimensional Printing', 'rapid prototyping', '3DP']",Metal Parts Generation by Three Dimensional Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08918ab7-33f2-4309-9250-3af3deab9645/download,,,,,,,,
"['Knight, Ronald', 'Wright, Joseph', 'Beaman, Joseph', 'Freitag, Douglas']",2018-11-14T18:04:24Z,2018-11-14T18:04:24Z,1996,Mechanical Engineering,doi:10.15781/T22V2CW3Q,http://hdl.handle.net/2152/70255,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLS', '3D CAD', 'DTM']",Metal Processing Using Selective Laser Sintering and Hot Isostatic Pressing (SLSIHIP),Conference paper,https://repositories.lib.utexas.edu//bitstreams/1274daa5-78ec-420f-aaff-8c6a18ffdac2/download,,"In July of 1995 the Office of Naval Research (ONR) awarded a contract to Loral Vought
Systems entitled Low Cost Metal Processing Using SLSIHIP. The two-phase, four-year program
is co-sponsored by ONR and the Defense Advanced Research Projects Agency, DARPA. The
program addresses the DoD and Navy need to improve the reprocurement, remanufacture and
repair methodology for high value metal parts. The specific program objective is to develop and
demonstrate Selec~:ve Laser Sintering (SLS) as a lower cost, flexible and faster method of
fabricating spare and replacement, small/medium sized powder metal parts for DoD weapon
systems. Current activity is f~cused on development of a high temperature SLS workstation and
on selective laser sintering trials on candidate metal powders including Inconel, molybdenum
and titanium.",,,,,,
"['Druschitz, A.P.', 'Cowden, S.', 'Dudley, A.', 'Walsh, S.', 'Weir, A.', 'Williams, C.B.', 'Wood, B.']",2021-11-01T21:16:36Z,2021-11-01T21:16:36Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89756,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['metal casting', '3D printed sand', 'mesostructure', 'ceramics', 'composites', 'encapsulation']",Metal-Ceramic Composite Lattice Structures Using 3D Printed Sand Molds and Cores,Conference paper,https://repositories.lib.utexas.edu//bitstreams/951a1e00-e10a-4968-9bac-11dfaf7d16c7/download,University of Texas at Austin,"Binder Jetting of sand molds for metal casting provides a scalable and efficient means of
fabricating large metal parts with complex geometric features made possible only by Additive
Manufacturing. For example, in earlier work, the authors demonstrated the use of Binder Jetting
to fabricate complex mold structures for casting large-scale, lightweight metallic lattice
structures and sandwich panels that could not be made through either traditional sand casting or
through other direct metal AM techniques. In this paper, the authors demonstrate the fabrication
of metal-ceramic composite lattice structures via embedding ceramic tiles into the printed mold
package. The addition of ceramic tiles can add resistance to penetrators and/or radiation
shielding to the lightweight lattice structures, which can be tailored for energy absorbing
performance. 3D printed mold and core designs for metal and metal-ceramic composite lattice
castings are described along with 3D printed mold designs for encapsulating individual metal or
ceramic tiles.",,,,,,
"['Zhang, Xinchang', 'Cui, Wenyuan', 'Li, Wei', 'Liou, Frank']",2021-11-04T15:53:06Z,2021-11-04T15:53:06Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89990', 'http://dx.doi.org/10.26153/tsw/16911']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['hybrid manufacturing', 'defect repair', 'laser metal deposition', 'reverse engineering']",Metallic Components Repair Strategies Using the Hybrid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/45c19c9e-0f31-42c3-a1f7-ffc0bd723e6d/download,University of Texas at Austin,"The hybrid manufacturing process which integrates additive manufacturing with
subtractive machining is competitive and promising in component repair. To automate this process,
detecting the missing volume and generating the deposition tracks is the key. In this study,
strategies for repairing defects on flat and non-flat surfaces were investigated. A cost-effective
reverse engineering tool was utilized to reconstruct STL models of damaged objects. Point data of
the fracture surface on flat surfaces was obtained to generate the tool path for material building up.
For defects on non-flat surfaces, the damaged model was best-fitted with the nominal model. Then
both models were sliced and by using area comparison method, the defective domain was detected.
Then a series of projection rays were utilized to slice the damaged cross-sections to extract the
repair volume. Finally, repair experiments were performed to assess the repair quality through
repair automation.",,,,,,
"['Fulcher, Ben', 'Leigh, David K.']",2021-10-11T20:20:31Z,2021-10-11T20:20:31Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88627', 'http://dx.doi.org/10.26153/tsw/15561']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Harvest Technologies', 'additive manufacturing', 'metal additive manufacturing', 'mechanical property characterization', 'geometrical production', 'aerosp', 'oil', 'aerospace']",Metals Additive Manufacturing Development at Harvest Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d4fb68b1-a01b-4773-99a5-f7eabc20552a/download,University of Texas at Austin,"Harvest Technologies received an EOS M280 in April of 2013 for the production of metal
parts through additive manufacturing (AM). Inconel 718 was chosen as a starting material due to
its high-end applications in the oil and aerospace industries. Two major areas are of high priority
in understanding the machine: (1) mechanical property characterization and (2) geometrical
production capability through building prototype models. The following is a working document
of Harvest’ progression in developing knowledge in the field of metals AM.",,,,,,
"['Tominski, J.', 'Lammers, S.', 'Wulf, C.', 'Zimmer, D.']",2021-11-08T23:37:44Z,2021-11-08T23:37:44Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90079', 'http://dx.doi.org/10.26153/tsw/17000']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['software-based design check', 'design check', 'complex structures', 'additive manufacturing', 'methodology']",Method for a Software-Based Design Check of Additively Manufactured Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/25bbb57c-8d73-47b4-bf26-60c99faa05aa/download,University of Texas at Austin,"Additive manufacturing offers the potential to produce complex structures such as
topology-optimized components or lattice structures. However, even these numerically generated
structures are subject to manufacturing restrictions. Therefore, compliance with design rules has to
be checked to ensure a robust production. For complex structures, this check requires a great effort.
Hence, a method for a software-based design check that automatically verifies the compliance with
design rules of complex structures has to be developed.
Within the framework of the developed method, the frequently used STL format which is
usually applied during preparation of the manufacturing process, is used. This format approximates
components using triangles. By systematically linking these triangles, geometrical attributes of
components which are relevant for a controlled manufacturing can be identified. Comparing these
attributes to a database containing attribute limits of divergent manufacturing conditions allows a
design check regarding robust manufacturing processes.",,,,,,
"['Stiltner, L. Justin', 'Elliott, Amelia M.', 'Williams, Christopher B.']",2021-10-05T14:33:55Z,2021-10-05T14:33:55Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88380', 'http://dx.doi.org/10.26153/tsw/15319']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['PolyJet™ process', '3D printing', 'actuated joints', 'fiber embedding']",A Method for Creating Actuated Joints via Fiber Embedding in a Polyjet 3D Printing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/471968d5-567a-44a5-a1c6-f0dac641ec84/download,University of Texas at Austin,"The Objet PolyJet direct 3D Printing process is capable of simultaneously depositing two distinct photopolymer
materials in preset combinations to enable designers to create parts with graded material properties. For example,
this dual-jet process offers designers the ability to combine elastomeric and rigid materials in order to create
integrated assemblies featuring stiff components and flexible joints and gaskets. To expand the potential of this
technology, the authors have developed a method for the direct fabrication of systems with actuated joints without
post-process assembly. The method, which involves temporarily pausing the build process and embedding and
anchoring fibers into the part, is described in this paper along with part design considerations. Two systems
featuring actuated joints are presented as a means of displaying the embedding method’s capabilities.",,,,,,
"['Elliott, A.M.', 'Nandwana, P.', 'Siddel, D.', 'Compton, B.G.']",2021-10-28T14:37:15Z,2021-10-28T14:37:15Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89652,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['powder bed density', 'binder-jet additive manufacturing', 'powder feedstock', 'shrinkage']",A Method for Measuring Powder Bed Density in Binder Jet Additive Manufacturing Process and the Powder Feedstock Characteristics Influencing the Powder Bed Density,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f413c638-27b9-490b-87bb-beca491ea6eb/download,University of Texas at Austin,"Powder bed additive manufacturing involves layer-by-layer spreading of powders before
melting, sintering or binding them. Traditionally apparent and tapped density measurements have
been carried out to get an estimate of the powder bed density. Powder bed density is especially
important in the case of binder-jet additive manufacturing where sintering is carried out as one of
the steps to achieve full densification. During densification, shrinkage occurs. The extent of
shrinkage depends upon the powder bed density. Thus, it is important to understand the role of
powder feedstock on controlling the powder bed density. In the present paper, we have
developed a technique to measure the powder bed density. We also used different powder
feedstock materials to understand the role of powder size distribution and morphology on the
powder bed density. The detailed results are presented.",,,,,,
"['Chen, Niechen', 'Frank, Matthew C.']",2021-11-04T13:55:24Z,2021-11-04T13:55:24Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89961,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['support structure', 'support removal', 'powder bed', 'metal additive manufacturing']",A Method for Metal AM Support Structure Design to Facilitate Removal,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8debb7ae-8cae-4db0-a2d5-f59e60743831/download,University of Texas at Austin,"For powder bed metal additive manufacturing (AM), additional post-processing for support
structure removal is required. However, this removal process is not formally considered during
the design of support structures. Therefore, when either manual or CNC milling is required, some
support structures may not be easily removed due to tool accessibility. In this research, with STL
model as input, tool accessibility is calculated and used to map onto the facets to grow supports
that are more amenable to machined removal. It provides a way to combine previous analysis on
support layout with additional information to guide suitable setups; ones that consider not only
critical angles requiring support but also removability. This work could enable better support
designs that will lead to higher throughput of metal AM by reducing effort and expense in post-process machining.",,,,,,
"['Auth, C.', 'Arndt, A.', 'Anderl, R.']",2021-11-08T22:18:38Z,2021-11-08T22:18:38Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90054', 'http://dx.doi.org/10.26153/tsw/16975']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['economic efficiency', 'additive manufacturing', 'conventional manufacturing', 'evaluation']",Method for the Evaluation of Economic Efficiency of Additive and Conventional Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4288190-74fa-4206-83ce-77c5c1260775/download,University of Texas at Austin,"The advantages of individuality and complexity for free are commonly known in the
field of additive manufacturing, but, nevertheless, they compete with advantages of
conventional manufacturing methods. On the one hand, a small size production can be
economically viable through additive manufacturing. On the other hand, conventional
manufacturing methods are well known and optimized, so that they have low cost per unit.
Therefore, to evaluate the economic efficiency various criteria are needed to compare additive
and conventional manufacturing methods. In the following part comparative criteria and
influence factors for economic efficiency are identified and described. Besides general aspects
personal reasons may influence a manufacturing decision. Therefore, the identified criteria are
used to build a method which helps the user to decide on a manufacturing method depending
on personal preferences. The structure and use of this method is described in the second part.
After this, an outlook and conclusion is given.",,,,,,
"['Sassaman, D.', 'Phillips, T.', 'Beaman, J.', 'Milroy, C.', 'Ide, M.']",2021-12-07T17:56:42Z,2021-12-07T17:56:42Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90737', 'http://dx.doi.org/10.26153/tsw/17656']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['powder flowability', 'pre-screening', 'revolution powder analysis', 'machine learning', 'selective laser sintering']",A Method of Predicting Powder Flowability for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38f634a5-6744-4bd2-91e0-2a92f55bc319/download,University of Texas at Austin,"This work investigates a method for pre-screening material systems for Selective Laser Sintering
(SLS) using a combination of Revolution Powder Analysis (RPA) and machine learning. To
develop this method, nylon was mixed with alumina or carbon fibers in different wt.% to form
material systems with varying flowability. The materials were measured in a custom RPA device
and the results compared with as-spread layer density and surface roughness. Machine learning
was used to attempt classification of all powders for each method. Ultimately, it was found that
the RPA method is able to reliably classify powders based on their flowability, but as-spread
layer density and surface roughness were not able to be classified.",,,,,,
"['Hartman, Aja', 'Zhao, Lihua']",2024-03-26T21:32:02Z,2024-03-26T21:32:02Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124419', 'https://doi.org/10.26153/tsw/51027']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['multi jet fusion', 'MJF', '3D printing', 'thermals', 'additive manufacturing']",Method to Balance Thermals for Multi-functional 3D MJF Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9e8a3c44-059c-4227-ba2f-03e38c5da683/download,University of Texas at Austin,"HP’s Multi Jet Fusion (MJF) is a powder-based additive manufacturing technology that
selectively melts polymer powder, in a layer-by-layer fashion to create 3D parts. There are
several different voxel properties that can be modulated using MJF including multi-color,
ductility, conductivity, among others. Creating mechanically uniform multi-material parts with
varying voxel properties throughout is challenging due to the liquid creating a competing
cooling and active absorbing components that effect the temperature of printed parts
differently. Here, we balance fusibility by utilizing a thermal imaging and an agent loading
sweep thermal profile characterization print for each individual agent. We then digitally control
the agent loading based on this data set and dynamic thermal imaging to produce a uniform
temperature profile. This ensures even fusing throughout multi-agent printed parts, shown by
uniform weight measurements of multi-color cubes from average weight 1.4 ± 0.2 g to 1.5 ±
0.1 g.",,,,,,
"['Mumtaz, K.', 'Vora, P.', 'Hopkinson, N.']",2021-10-04T20:23:25Z,2021-10-04T20:23:25Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88338', 'http://dx.doi.org/10.26153/tsw/15277']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['metal powder bed', 'additive manufacturing', 'anchors', 'supports', 'overhanging features', 'laser processing', 'powder bed']",A Method to Eliminate Anchors/Supports from Directly Laser Melted Metal Powder Bed Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a0c3d29a-74ea-4e89-9a75-be8ed505bf3c/download,University of Texas at Austin,"Metal powder bed AM processes have a significant drawback in that they require
anchors/supports to hold overhanging features down during laser processing. This severely
restricts the geometries that the processes can make, adds significant time and cost to production
and reduces throughput as parts cannot be easily stacked in the build bed. A method to eliminate
the need for these anchors/supports has been invented and will be described. Early parts made
without anchors will be shown and next steps for research will be discussed.",,,,,,
"['Guduri, Sashidhar', 'Crawford, Richard H.']",2018-04-19T16:35:34Z,2018-04-19T16:35:34Z,1992,Mechanical Engineering,doi:10.15781/T2KS6JN34,http://hdl.handle.net/2152/64381,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'Constructive Solid Geometry', 'CSG']",A Method to Generate Exact Contour Files for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2e5f03d-cf12-4d19-8586-739e32005609/download,,"Existing methods to create contour files generate a polygonal approximation of
the contours instead of an exact representation. This paper presents a method to generate
exact contours from Constructive Solid Geometry (CSG) representations. The method
preserves the accuracy of the contour files provided the primitives used to generate the
CSG tree are polygonal or quadric objects. Due to the inclusion of quadric objects into
the primitive set an additional effort to solve for the intersection points between two
quadric curves is required. The paper also presents a method to convert piecewise
quadratic contours to toggle point files for raster scanning solid freeform fabrication
processes.",,,,,,
"['Ott, M.', 'Meihofener, N.', 'Mozgova, I.']",2024-03-26T17:12:28Z,2024-03-26T17:12:28Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124380', 'https://doi.org/10.26153/tsw/50988']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['neural network', 'design time', 'design', 'additive manufacturing']",Methodical Approach to Reducing Design Time by using Neural Networks in Early Stages of Concept Development,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bde10f58-b6b3-4c3a-8038-cd07c762c6bb/download,University of Texas at Austin,"Modern companies often face various challenges in concept development of products or systems.
Design engineers prepare initial concepts as 3D models. These are then simulated by computational
engineers. If requirements are not met, this necessitates an iterative process that runs between the
design and computation departments until a valid concept is created. Design methods such as
topology optimization are often used here. The upcoming result is then attempted to be adapted to
certain manufacturing processes. These iteration loops can sometimes take a very long time, since
the model construction and structural optimization generate large computational efforts. The
present work shows on an example a methodical approach, which represents a first proof of
concept, to solving this problem, including a description of methods and techniques, as well as
possible problems in a detailed analysis concerning training data for neural networks and their
abstraction capabilities. It is evident that additional research work needs to be conducted for further
utilization in order to address all arising questions.",,,,,,
"['Borstell, D.', 'Walker, N.', 'Kurz, S.']",2021-11-30T20:51:53Z,2021-11-30T20:51:53Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90543', 'http://dx.doi.org/10.26153/tsw/17462']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['orthosis', 'left hand', 'double bass', 'perception', 'methodology', '3D printing']",Methodical Design of a 3D-Printable Orthosis for the Left Hand to Support Double Bass Perceptional Training,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ca0a87c-14b3-4765-a94c-4274ae8e29f2/download,University of Texas at Austin,"The evolution of Additive Manufacturing (AM) in the past decades has opened up its
use to a wide range of new applications where conventional manufacturing methods dominated.
Orthoses are medical devices, mostly used on legs or arms after injuries or surgery. Amongst
other functions, they limit the possible movement of limbs or joints to prevent excessive
movements or loads during remobilization. Their manufacturing process is predominantly
manual and conventional using e.g. plaster casts and materials like foam, wood and textiles.
Playing the acoustic double bass requires precise positioning of the left hand fingers on
the fingerboard. Perception of the finger spacing is very important for good intonation.
Different educational approaches have therefore been made to kinesthetic and perceptional
training. Miniaturization and low forces allow applying additive manufacturing technology to
a previously conventional device leading to a new approach to design a perceptional training
device for the left hand: an individually shaped orthosis, which is lightweight, low cost, and
adjustable and which can be worn during instrument practice.",,,,,,
"['Uí Mhurchadha, S.M.', 'Huynh, M.P.', 'Quinn, P.T.', 'Tomaz, I.', 'Raghavendra, R.']",2021-12-01T22:01:47Z,2021-12-01T22:01:47Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90630', 'http://dx.doi.org/10.26153/tsw/17549']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['smart components', 'experimental characterisation', '316L stainless steel', 'smart component']",A Methodology for the Embedding of Sensors in Components Manufactured Using Metal Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1df0ad21-48a8-4df5-8019-326925f53fbc/download,University of Texas at Austin,"This paper presents a methodology for the embedding of a sensor in a 316L stainless steel component
during the laser powder bed fusion process. The aim of this study is to overcome the drawbacks of traditional
sensor attachment to the surface of a component via placing sensors into a part during the manufacturing process.
A methodology for the embedding process that ensures the functionality of the sensor within the component is
presented and a preliminary investigation into the effect of the embedding process on the manufactured part
quality preformed. An off-the-self accelerometer was embedded into a turbine and tested under rotational loading
conditions. The interface microstructure where the print was stopped is also studied to investigate the effect of
the sensor embedding methodology on material properties. The embedded sensor is capable of detecting off-axis
rotation and over-speed of the turbine, two critical loading conditions that cause failure in turbines.",,,,,,
"['Tyvaert, Irenee', 'Fadel, Georges', 'Rouhaud, Emannuelle']",2019-03-08T17:40:53Z,2019-03-08T17:40:53Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73571', 'http://dx.doi.org/10.26153/tsw/713']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Reverse Engineering', 'Rapid Prototyping']",A Methodology to Create STL Files from Data Point Clouds Generated with a Coordinate Measuring Machine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e63b2b9-7796-47eb-bc53-34f535ed8451/download,,"Industries have always had the need to reproduce objects especially when drawings
are no longer or were never available (reverse engineering). Coordinate measurement
machines, whether touch- or laser-based, enable users to generate a point cloud representing
a surface. The aim of this work is to develop a methodology and its translation into a
software program to generate closed STL file models from such data point clouds.
The first step in the research is to develop an algorithm to merge several surfaces
(data point clouds) from a real object in exactly the same reference frame. Then, a
tessellation program is implemented to creat~ the STL file considering computational costs
and minimizing the number oftriangles while maintaining the accuracy ofthe original part.
The implementation is illustrated on two examples and conclusions are drawn.",,,,,,
"['Nikoukar, Mohammad', 'Patil, Nachiket', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-11T21:15:30Z,2021-10-11T21:15:30Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88644', 'http://dx.doi.org/10.26153/tsw/15578']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Cholesky algorithm', 'stiffness matrix', 'additive manufacturing', 'thermo-mechanical properties prediction', 'finite element analysis']",Methods for Enhancing the Speed of Numerical Calculations for the Prediction of the Mechanical Behavior of Parts Made Using Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b3a9e96f-f46d-4563-8e69-faa54f43fc6d/download,University of Texas at Austin,"Finite element modeling (FEM) is one of the most common methods for predicting the thermo-mechanical
properties of 3D structures. Since FEM was developed primarily to analyze and optimize structures that would
then be mass-produced, the time for modeling was small compared to the time required to produce the
components. With the advent of Additive Manufacturing (AM) it is now possible to produce and test complex
parts more quickly than FEM methods can predict their mechanical performance. As such, an enhanced
numerical method for quickly solving for the mechanical behavior of components is needed to fully take
advantage of the speed and versatility of this new manufacturing paradigm.
In order to enhance the computational efficiency of FEM, a novel method was developed to adapt FEM for
prediction of fundamental deformation responses of AM-produced parts. A general FEM strategy comprised of
constructing the stiffness and external stimuli (such as laser power or pressure) as matrices and vectors
respectively has been formulated. Thermo-mechanical response is calculated by obtaining the compliance
matrix from the stiffness matrix and then multiplying the corresponding values of the compliance matrix with
the external stimulus vector. Obtaining the compliance matrix from the stiffness matrix is accomplished, in
most cases, using a well-known Cholesky algorithm which starts by transforming the stiffness matrix into a
lower triangular matrix with zeros above its diagonal [1]. In this study, the Cholesky algorithm has been
improved by identification of discrete sparse bands and by eliminating many zero multiplications in the lower
triangular matrix to obtain the thermo-mechanical response much faster than currently available algorithms. In
addition, the vector based storage strategy of the above-mentioned discrete sparse bands and multipliers have
been used to save computer storage space, including free cache memory, resulting in faster computations. An
example showing the time advantage of this new framework over previously used algorithms to obtain the
deformation response of an additively manufactured axial beam is provided along with its theoretical
background.",,,,,,
"['Turk, Tunay', 'Hung, Chia-Hung', 'Hossein Sehhat, M.', 'Leu, Ming C.']",2021-12-06T23:21:04Z,2021-12-06T23:21:04Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90714', 'http://dx.doi.org/10.26153/tsw/17633']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['automation', 'laser foil printing', 'laser based metal additive manufacturing']",Methods of Automating the Laser-Foil-Printing Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63872eea-9d98-4b53-9149-1e48fb746a68/download,University of Texas at Austin,"Laser Foil Printing (LFP) is a laser-based metal Additive Manufacturing (AM) method
recently developed at Missouri University of Science and Technology. This study investigates and
compares two different methods of automating part fabrication for the LFP process. Specifically,
the edge elevation issue due to laser cutting is investigated. Edge elevation occurs after the foil
cutting operation, which is an essential step of the LFP process. Previously, mechanical polishing
was done to remove the elevated edges for the fabrication of each layer. However, as mechanical
polishing is very time-consuming, the current study focuses on two other methods to eliminate the
elevated edges. One of them uses laser polishing to remove the elevated edges. Another method is
changing the order of the fabrication steps between pattern welding and contour cutting in the LFP
process. Comparisons are made to observe the differences in part quality, properties, and building
time between these two methods.",,,,,,
"['Beller, Z.J.', 'Secor, E.B.', 'Lavin, J.', 'Keicher, D.M.', 'Essien, M.', 'Whetten, S.', 'Mani, S.S.']",2021-11-10T21:33:16Z,2021-11-10T21:33:16Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90182', 'http://dx.doi.org/10.26153/tsw/17103']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['anti-reflective coatings', 'optics', 'deposition', 'deposition methods', 'additive manufacturing']",Methods of Depositing Anti-Reflective Coatings for Additively Manufactured Optics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ea7613d-96ae-4708-b796-89c10f02b8cb/download,University of Texas at Austin,"Recent advancements in the field of additive manufacturing (AM) have enabled the
production of high-fidelity optical components allowing for the design of novel fiber optic
systems. In order to support this emerging technology, methods of depositing anti-reflective
coatings (ARCs) onto these optical components must be developed. Work has begun to identify
such coating materials; develop systems capable of accurately depositing controlled, uniform
layers onto given substrates; establish deposition procedures for ensuring coating validity; and
establish post-processing procedures to ensure the reliability of finished components. Areas of
interest for finished components include their integration into high-bandwidth fiber optic
systems, enabling further miniaturization of communication components. Methods of ARC
deposition will be discussed along with final component performance and the identification of
key process parameters affecting product performance.",,,,,,
"['Li, Wenbin', 'Ghazanfari, Amir', 'Leu, Ming C.', 'Landers, Robert G.']",2021-10-19T20:21:00Z,2021-10-19T20:21:00Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89331,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['extrusion-on-demand', 'high solids', 'loading ceramic pastes', 'ceramics paste', 'ram extruder', 'needle valve', 'auger valve']",Methods of Extrusion on Demand for High Solids Loading Ceramic Paste in Freeform Extrusion Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/34c67d5f-9812-42c0-9852-b10b20c8bc85/download,University of Texas at Austin,"Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid
freeform fabrication processes requires a precise control of the extrusion flow rate to dispense
material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion
process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian
behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram
extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high
solids loading (i.e., >50%, volumetric) aqueous alumina paste. Optimal extrusion process
parameters for these methods are determined through printing tests and analysis. The extrusion
performance in terms of extrusion start and stop accuracy, as well as flow rate consistency, is
compared and analyzed for the three methods. Advantages and disadvantages of these three
methods are also discussed.",,,,,,
"['Hiller, Jonathan', 'Lipson, Hod']",2020-03-09T14:37:05Z,2020-03-09T14:37:05Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80186', 'http://dx.doi.org/10.26153/tsw/7205']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Digital Freeform Fabrication,Methods of Parallel Voxel Manipulation for 3D Digital Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19642b97-a6ed-4c86-bd2e-581793b828c8/download,,"A novel digital printing concept is explored for desktop fabrication of multimaterial objects with arbitrary 3D geometry. Digital objects are composed of
many discrete, self-aligning voxels instead of continuous (analog) deposition
techniques. Overall accuracy is determined by the individual voxels instead of the
printer, and digital properties such as perfect replication and error correction are
physically meaningful. The key challenge in digital printing is massively parallel,
deterministic voxel manipulation. To quickly print millions of voxels while
keeping errors low, we propose a parallel manufacturing process that exploits
electrostatic forces to place an entire 2D pattern of voxels concurrently. Using a
custom charged print head, we demonstrate selective 1.5mm voxel pick-up within
a larger, self-aligned layer. We expect the principle to scale to million voxel
layers using currently available technology.",,,,,,
"['Fischer, J.', 'Kniepkamp, M.', 'Abele, E.']",2021-10-12T19:56:56Z,2021-10-12T19:56:56Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88727', 'http://dx.doi.org/10.26153/tsw/15661']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Micro Laser Melting', 'additive manufacturing', 'micro manufacturing', 'micro parts', '316L steel powder']",Micro Laser Melting: Analyses of Current Potentials and Restrictions for the Additive Manufacturing of Micro Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/52c78606-f603-4060-8b93-ebaeaa73b649/download,University of Texas at Austin,"Although there is a significant requirement for complex micro parts, current metal processing
additive manufacturing techniques are limited in achievable part accuracy and geometric
resolution. Due to the recently developed process of Micro Laser Melting (MLM) new
potentials in micro manufacturing are realizable.
This paper gives an overview of the present potentials of MLM using 316L steel powder.
While using powder material with a grain size of ≤ 5 µm this technique enables layer
thicknesses from 5 to 7 µm. Due to the use of different exposure strategies and laser modes
(pulsed and continuous radiation) high aspect ratios up to 260 could be realized with thin wall
structures. Furthermore, the influence of laser mode and exposure sequence on the part
density, surface quality and accuracy of lattice structures with a minimum wall thickness
lower than 40 µm is analyzed.",,,,,,
"['Cheng, Xudong', 'Schwieso, Patrick', 'Choi, Hongseok', 'Datta, Arindom', 'Li, Xiaochun']",2020-02-13T20:54:10Z,2020-02-13T20:54:10Z,8/30/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79977', 'http://dx.doi.org/10.26153/tsw/7002']",,2004 International Solid Freeform Fabrication Symposium,Open,process monitoring,Micro Thin Film Sensor Embedding in Metal Structures for Rapid Production of Miniature Smart Metal Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4000a7f2-e545-49fa-b208-3c8106b943f3/download,,"In-situ monitoring and control of temperature and strain is important to improve
product quality for numerous mesoscale manufacturing processes. However, it is difficult for
conventional sensors to provide measurements with a high spatial and temporal resolution at
critical locations. This paper studies the fabrication and calibration of micro thin film sensors
embedded in metal structures for miniature tooling applications. Micro thin film sensors have
been successfully fabricated on various metal substrates and advanced embedding techniques
have been developed to ensure sensor function inside metal structures. Specifically, multilayer
dielectric/metal thin film micro sensors were embedded into layered metal structures by
ultrasonic welding (USW). These embedded sensors provided superior spatial and temporal
resolutions. Smart tooling technique will improve safety and reliability significantly for
manufacturing processes.",,,,,,
"['Shuai, Li', 'Wei, Qingsong', 'Shi, Yusheng', 'Zhang, Jie', 'Wei, Li']",2021-10-26T20:14:55Z,2021-10-26T20:14:55Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89574,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['micro-crack formation', 'selective laser melting', 'Inconel 625']",Micro-Crack Formation and Controlling of Inconel625 Parts Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2408600f-16a0-4a2f-a705-821469aac4ae/download,University of Texas at Austin,"Micro-crack is one of the most serious defects in selective laser melting (SLM), which
impair the mechanical properties of the fabricated parts. In this study, Inconel625
superalloy specimens were fabricated by SLM process with progressive alternative
scan strategy. The morphology of the cracks, elements distribution were detected by
optical microscope (OM), scanning electron microscope (SEM) and electron back
scattered diffraction (EBSD). The results showed that a large numbers of micro-cracks
occurred at room temperature, with the average length of approximately 100 µm. It
was found that crack formation was attribute to the local segregation of Nb and Mo
element in the process of rapid solidification, resulting in the generation of low
melting temperature eutectic solidification (γ+Laves). Micro-cracks grows along the
interface of (γ+Laves) under the thermal stress. Base-plate preheating shows an
efficient method to reduce the scales and number of cracks. The residual stress was
reduced by more than 50% when preheating at 300℃.",,,,,,
"['Ware, Henry Oliver T', 'Sun, Cheng']",2021-11-16T15:29:48Z,2021-11-16T15:29:48Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90314', 'http://dx.doi.org/10.26153/tsw/17235']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['microCLIP', 'high-resolution fabrication', 'ceramic resin', 'ceramic resins', 'dimensional accuracy', '3D printing']",microCLIP Ceramic High-Resolution Fabrication and Dimensional Accuracy Requirements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4bc8ef78-ae46-4dd1-a261-adc2314fa270/download,University of Texas at Austin,"Ceramics have been broadly used as structural and functional materials with a wide range
of engineering applications. Recent introduction of Continuous Liquid Interface Production
(CLIP) uses projection UV photopolymerization and oxygen inhibition to tremendously reduce
fabrication time. In addition to 3D printing polymeric materials, it has demonstrated the feasibility
of fabricating 3D ceramic parts using photo-curable ceramic resins. However, the associated
ceramic particle light-scattering significantly alters the process characteristics of the CLIP process,
resulting in broadening of the lateral dimensions in associated with the reduction in the curing
depth. Varying the exposure conditions to accommodate the scattering effect further affects the
deadzone thickness, which introduces a systematic defocusing error to further complicate the
process control. In this work we show that careful characterization and balance of both effects
yields an optimal set of process parameters (UV Power and stage speed) for high-resolution 3D
fabrication with a given photo-curable ceramic resin.",,,,,,
"['Vail, N.K.', 'Barlow, J.W.']",2018-04-10T16:20:43Z,2018-04-10T16:20:43Z,1990,Mechanical Engineering,doi:10.15781/T2R78658X,http://hdl.handle.net/2152/64234,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['The Center for Materials Science and Engineering', 'Department of Chemical Engineering', 'Selective Layer Sintering', 'SLS']",Microencapsulation of Finely Divided Ceramic Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f21f2bd3-a186-49ef-9040-33b4ad5d2347/download,,"Polymer coated alumina particles have been prepared by spray
drying alumina powder with a polymer emulsion. Powders containing a
maximum of 50% wt. were obtained. The coated particles were compared
to mixtures of alumina and polymer. Oven sintering tests show the coated
material to compact more than the mixed and pure polymer materials.
Strong, well defined parts with layer thicknesses of 0.002"" were produced
from both coated and mixed materials by the Selective Layer Sintering
process.",,,,,,
"['Udofia, Edidiong Nseowo', 'Zhou, Wenchao']",2021-11-15T21:45:57Z,2021-11-15T21:45:57Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90280', 'http://dx.doi.org/10.26153/tsw/17201']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['microextrusion', '3D printing', 'evaporation timescale', 'capillary rise', 'standoff distance', 'substrate driven ink flow', 'surface energy', 'PDMS printing']",Microextrusion Based 3D Printing – A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f122912-7900-4083-9add-268872eed30d/download,University of Texas at Austin,"Whilst extrusion-based 3D printing processes have been successfully applied at the macroscale,
this seeming simplicity belies the dynamic complexities needed for consistent, repeatable and cost-effective printing at the microscale. To fully tap into the promise of microextrusion (µEP) of
fabricating fine resolution features, it is critical to establish an understanding of the fundamentals
of ink flow, interface energy, drying, and the process-property relationship of the printing process.
Till date, a comprehensive and coherent organization of this knowledge from relevant literature in
different fields is still lacking. In this paper, we present a framework of the underlying principles
of the microextrusion process, offering an overall roadmap to guide successful printing based on
both results in the literature and our own experimental tests. The impacts of various process
parameters on the resolution of printed features are identified. Experiments are carried out to
validate the developed framework. Key challenges and future directions of microextrusion 3D
printing are also highlighted.",,,,,,
"['Griffith, Michelle', 'Yang, Pin', 'Burns, George', 'Harris, Marc']",2019-11-15T16:05:02Z,2019-11-15T16:05:02Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78418', 'http://dx.doi.org/10.26153/tsw/5505']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Femtosecond,Microfabrication with Femtosecond Laser Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/45cf4965-26eb-4cd5-a759-bc348c972b8d/download,,"Our research investigates the special characteristics of femtosecond laser processing for
microfabrication. The ultrashort pulse significantly reduces the thermal diffusion length. As a
result, material is removed more efficiently with little damage to the surrounding feature volume.
Currently, we are exploring the basic mechanisms that control femtosecond laser processing, to
determine the process parameter space for laser processing of metals to address manufacturing
requirements for feature definition, precision and reproducibility. One of the unique aspects to
femtosecond radiation is the creation of localized structural changes. By scanning the focal point
within a transparent material, we can create three-dimensional waveguides.
This paper will describe our results to explore femtosecond laser ablation for laser
processing of metals and glasses. We will discuss the effect of laser parameters on removal rate,
feature size/definition, aspect ratio, material structure, and performance. Examples of
component fabrication in metals and glasses will be shown.",This work supported by the U. S. Department of Energy under contract DE-AC04-94AL85000.,,,,,
"['Holt, Nicholas', 'VanHorn, Austin', 'Montazeri, Masha', 'Zhou, Wenchao']",2021-11-03T21:58:35Z,2021-11-03T21:58:35Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89945,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'MAPS', 'MEMS', 'microheaters', 'printed electronics', 'powder bed processes']",Microheater Array Powder Sintering: A Novel Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e8ae28f9-3f23-4898-a13f-323ee2cb9ae2/download,University of Texas at Austin,"One of the most versatile additive manufacturing (AM) processes is selective laser sintering (SLS), which
scans a powder bed with a laser beam to fuse powder particles layer by layer to build 3D objects for prototypes
and end products with a wide range of materials. However, it suffers from slow printing speed due to the
pointwise scanning and high energy consumption due to the requirement of a high-power laser. In this paper,
we propose a novel method of additive manufacturing which replaces the laser beam with an array of
microheaters as an energy source to sinter powder particles. This method, referred to as Microheater Array
Powder Sintering (MAPS), has the potential to significantly increase the printing speed by layer-wise
sintering and reduce the power consumption due to the lower power requirements of the microheater array.
This paper is to provide a proof-of-concept for this proposed new method. First, a thin-film microheater is
designed and simulated with an experimentally validated numerical model to demonstrate that it can be used
as an alternative energy source to sinter powder particles by reaching a target temperature of 600°C within
milliseconds at a power consumption of 1.2 Watts. The numerical model is used to simulate the MAPS
process by placing the heater in close proximity to the powder particles. Simulation results show that heat
can be effectively transferred over an air gap to raise the temperature of the powder particles to their sintering
temperature. Different process parameters (e.g., air gap, material properties, time, printing resolution, etc.)
are discussed. An experimental MAPS system is then implemented to provide a proof-of-concept with the
designed microheater and a custom air gap control apparatus. A straight line is successfully printed on thermal
paper using the experimental MAPS system, which suggests the proposed MAPS process is feasible.",,,,,,
"['Crane, Nathan', 'Nellis, Mike', 'Nolas, George', 'Harmon, Julie']",2020-03-09T13:11:50Z,2020-03-09T13:11:50Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80170', 'http://dx.doi.org/10.26153/tsw/7189']",eng,2007 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,Microscale Freeform Integration by Directed Self Assembly,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b090578e-3e0a-4723-9c65-690e82cffead/download,,"Most solid freeform fabrication (SFF) manufacturing processes assemble uniform
components such as powder particles or polymer chains to produce desired geometries. Their
capacity for producing highly functional parts (integrated actuation, sensing, and electronics)
will dramatically increase when multiple materials and functional subcomponents can be
automatically integrated. This paper addresses criteria for a system that integrates multiple
materials and components through computer-controlled self-assembly. It builds complex systems
from layers of self-assembled micro-components. The paper will address implementation
methods, present a concept demonstration, and consider its application to micro-thermoelectric
systems. This manufacturing process can be enhanced further through integration with mature
additive processes.",,,,,,
"['Xu, Yi', 'Imamura, Masato', 'Nakagawa, Takeo']",2018-11-29T20:28:05Z,2018-11-29T20:28:05Z,1997,Mechanical Engineering,doi:10.15781/T27S7JC2B,http://hdl.handle.net/2152/70340,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Stereolithography', '3D objects']",Microscopic Flow Observation of Photopolymer by UV-Laser Beam Exposure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f89cc208-2b06-4a77-86d3-b06c7ea22e2d/download,,"Microscopic flow of liquid photopolylner around the cured polymer was observed
during laser exposure. The maximum velocity was about 4 mm/s. The temperature raised by
reaction heat, causes the density of liquid photopolymer to vary, resulting in this flow. This
flow causes the nearby cured strands to sway and it decreases the accuracy of SL model.",,,,,,
"['Chartrain, Nicholas A.', 'Vratsanos, Maria', 'Han, Dung T.', 'Sirrine, Justin M.', 'Pekkanen, Allison', 'Long, Timothy E.', 'Whittington, Abby R.', 'Williams, Christopher B.']",2021-10-28T21:59:25Z,2021-10-28T21:59:25Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89711,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['tissue scaffold', 'regenerative medicine', 'stereolithography', 'biodegradable', 'polymer']",Microstereolithography of Tissue Scaffolds Using a Biodegradable Photocurable Polyester,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13a2bcaf-6214-4e3a-9ee0-ba4729919841/download,University of Texas at Austin,"Due to its ability to create complex cellular geometries with extremely fine resolution, mask
projection microstereolithography (MPμSL) can be useful for fabricating designed tissue
scaffolds and other biological constructs for use in Tissue Engineering and Regenerative
Medicine. However, few photocurable materials with low cytotoxicity, adequate cell adhesion,
and degradability can be processed with MPμSL. In this work, we present the fabrication of
biocompatible and biodegradable tissue scaffolds with 50 μm feature sizes from a novel
polyester using MPμSL. Poly(tri(ethylene glycol)adipate) dimethacrylate (PTEGA-DMA) was
synthesized and evaluated for its printability. The curing parameters for printing were identified
and scaffolds were fabricated. Optical and electron microscopy were used to determine the
achievable feature sizes and accuracy of printed parts using the polymer in the MPμSL system.
MC3T3-E1 mouse preosteoblasts were seeded on PTEGA-DMA films to assess adhesion and
biocompatibility.",,,,,,
"['Hanumantha, M.', 'Farhang, B.', 'Ravichander, B.B.', 'Ganesh-Ram, A.', 'Ramachandra, S.', 'Finley, B.E.', 'Swails, N.', 'Amerinatanzi, A.']",2021-12-06T22:41:51Z,2021-12-06T22:41:51Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90702', 'http://dx.doi.org/10.26153/tsw/17621']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'overhangs', 'IN718', 'microstructure', 'Vickers hardness']",Microstructural and Mechanical Characterization of Laser Powder Bed Fusion of IN718 Overhangs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53ceec45-b4b0-461b-b46b-1bfb2b0a511b/download,University of Texas at Austin,"Inconel 178 (IN718), a nickel-chromium-based superalloy known for its superior properties is used
in aerospace, oil, and gas industries. Due to its high hardness, IN718 is difficult to be machined.
Therefore, fabrication of IN718 components with complex geometries is a big challenge when
conventional manufacturing techniques are used. Laser powder bed fusion (LPBF) technique can
be used to fabricate IN718 parts with high precision. During fabrication of overhang structures,
supports are typically employed, which significantly increases the use of resources such as material
consumption and postprocessing. The focus of this study is to determine the angle at which an
overhang structure can be fabricated without employing supports. To this aim, the angled-overhang samples with varied angles (30°-90°) were manufactured with no support. The effect of
overhang state on the microstructural and mechanical properties of the LPBF-processed IN718
samples was analyzed. According to the microstructural analysis, the deepest melt pools in the
overhang sample seemed to be at a hanging angle of 45°. Moreover, the overhang sample
fabricated at 45° had the greatest Vickers hardness value of 382.90 HV. This study urges a
reconsideration of the common approach of selecting supports for overhang samples in the LPBF
process when a higher quality of the as-fabricated parts is desired.",,,,,,
"['Ewing, Cody', 'Wu, Yan', 'Yang, Li']",2021-11-09T20:01:18Z,2021-11-09T20:01:18Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90149', 'http://dx.doi.org/10.26153/tsw/17070']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['Ti6Al4V', 'cellular struts', 'microstructure', 'mechanical characterization', 'electron beam powder bed fusion', 'EB-PBF', 'additive manufacturing']",Microstructural and Mechanical Characterization of Ti6Al4V Cellular Struts Fabricated by Electron Beam Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/64ea57a6-a79f-46c7-ac6f-a98cb795e7b9/download,University of Texas at Austin,"Despite the widespread use of the electron beam powder bed fusion (EB-PBF) additive
manufacturing (AM) process in the fabrication of cellular structures, relatively little is known
about the microstructural and mechanical properties of the individual cellular struts of different
geometries fabricated by the EB-PBF. In this study, experimental investigation was carried out in
the attempt to establish preliminary understanding of the material characteristics of the Ti6Al4V
cellular struts using EB-PBF under various geometry design conditions (dimension and orientation
angle). It was found that there exist significant geometry effects for the material characteristics of
the Ti6Al4V cellular struts, which indicates that a non-uniform material model should be
considered in the future design of these cellular structures.",,,,,,
"['Ning, Fuda', 'Hu, Yingbin', 'Liu, Zhichao', 'Wang, Hui', 'Cong, Weilong', 'Li, Yuzhou']",2021-10-27T21:15:57Z,2021-10-27T21:15:57Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89616,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser engineered net shaping', 'LENS', 'Al2O3 nanoparticle reinforced composites', 'microstructures', 'microhardness', 'compressive properties']",Microstructural and Mechanical Performance of Al2O3 Nanoparticle Reinforced 17-4 PH Stainless Steel Bulk Composite Parts Fabricated by Laser Engineered Net Shaping Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1465a78a-c1ce-461f-ad14-38ebff18d12a/download,University of Texas at Austin,"Alloy 17-4 PH (AISI 630) is a precipitation-hardening martensitic stainless steel that has
been extensively employed in the industries of aerospace, marine, and chemical. In this study,
bulk parts of both 17-4 PH and Al2O3 reinforced 17-4 PH composites were fabricated on a steel
substrate by laser engineered net shaping (LENS) process to investigate the effects of Al2O3
reinforcements on the part performance. The 17-4 PH powders were pre-mixed with Al2O3
nanoparticles by ball milling. The microstructures of both parts were observed using scanning
electron microscopy and mechanical properties including microhardness and compressive
properties were evaluated by means of a Vickers microhardness tester and a universal tester,
respectively. The results indicate that Al2O3 reinforced 17-4 PH composite parts fabricated by
LENS process exhibited superior microhardness and compressive properties as compared to pure
17-4 PH parts.",,,,,,
"['Lakshminarayan, Uday', 'Marcus, H.L.']",2018-04-17T18:16:25Z,2018-04-17T18:16:25Z,1991,Mechanical Engineering,doi:10.15781/T2RN30R1X,http://hdl.handle.net/2152/64340,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Selective Laser Sintering', 'SLS', 'material systems']",Microstructural and Mechanical Properties of Al2O3/P2O5 AND Al2O3/B2O3 Composties Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/af8d903c-bafc-4f6d-b83b-8797923a8ff2/download,,"The feasibility of processing ceramic powders by Selective Laser Sintering has been
reported in an earlier paperl . Material systems we have investigated include alumina based
systems with ammonium phosphate or boron oxide as low temperature binders which are
the systems discussed in this paper. With bOth systems, a secondary heat treat.rJ1ent is
necessary to realize the high temperatute properties of the materials. This paper will focus
mainly on the mechanical properties of the composite bodies. In particular, the influence of
particle size, powder mix composition, laser parameters and secondary heat treat.rJ1ent on
density, strength and dimensional stability of the final product will be discussed.",,,,,,
"['Doris, A.', 'Trujillo, I.', 'Godinez, D.', 'Arrieta, E.', 'Wicker, R.B.', 'Gradi, P.', 'Katsarelis, C.C.', 'Medina, F.']",2024-03-26T16:36:49Z,2024-03-26T16:36:49Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124362', 'https://doi.org/10.26153/tsw/50970']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['Inconel 718', 'laser powder bed fusion', 'geometric feature build plate', 'multiple machine configurations', 'heat treatment', 'microindentation hardness', 'optical microscopy', 'EBSD image mapping', 'microstructure']",Microstructural and microhardness variations of laser powder bed fusion (L-PBF) additively manufactured Inconel 718 due to machine variability and wall thickness for aerospace applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08671889-83a3-4fa1-8021-0a78d6ffdaaf/download,University of Texas at Austin,"This paper reports on a study investigating the microstructure and microhardness of thin walls
fabricated by Laser Powder Bed Fusion (L-PBF) from sixteen geometric feature build plates. The
study evaluated any variance in those properties with the variation in thickness by characterizing
the XY and YZ planes of seven thin walls of different thicknesses and the base parts. Electron
Backscatter Diffraction (EBSD) analysis with inverse pole figure (IPF) mapping was done for four
samples from four different machine manufacturers. From the EBSD grain boundary map, the
microstructure is composed of equiaxed grains with a lower threshold angle with smaller grains in
the border area. Compositional analysis for both the powders and the resulting fully heat-treated LPBF manufactured material was analyzed for alloy element stability and contaminants using 10 mg
samples. The paper concludes by showing the relationship between composition and
microstructural properties.",,,,,,
"['Gong, X.', 'Lydon, J.', 'Cooper, K.', 'Chou, K.']",2021-10-12T22:59:01Z,2021-10-12T22:59:01Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88765', 'http://dx.doi.org/10.26153/tsw/15699']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['electron beam additive manufacturing', 'additive manufacturing', 'beam scanning speed', 'microstructure', 'Ti-6Al-4V']",Microstructural Characterization and Modeling of Beam Speed Effects on Ti-6Al-4V by Electron Beam Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d2a06ce7-348d-45c8-a4a1-4e01b5e910a1/download,University of Texas at Austin,"In this study, the influence of the beam scanning speed to the microstructure of Ti-6Al4V parts processed by EBAM is investigated. EBAM parts were fabricated with 4 different
scanning speeds, ranging from 214 mm/s to 689 mm/s, and the microstructures were studied. In
addition, the volume fractions of different phases were obtained by thermal and phase
transformation modeling. The microstructure is characterized by columnar structures of prior β
grains along the build direction, and fine Widmanstätten (α+β) structure and α′ martensites are
presented inside of the prior β. Both the prior β grain size and α-lath thickness decrease with the
increase of the scanning speed. For the phase constitution, the volume fraction of α′ increases
with the scanning speed while the volume fraction of α decreases due to the increase of cooling
rate during solid phase transformation. The results from the analytical phase transformation
model are consistent with the microstructure characterization from the experiment.",,,,,,
"['Fu, Tian', 'Fan, Zhiqiang', 'Pulugurtha, Syamala R.', 'Sparks, Todd E.', 'Ruan, Jianzhong', 'Liou, Frank', 'Newkirk, Joseph W.']",2020-03-10T17:37:47Z,2020-03-10T17:37:47Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80236', 'http://dx.doi.org/10.26153/tsw/7255']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Laser Direct Metal Deposition,Microstructural Characterization of Diode Laser Deposited Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e61495da-acd9-4974-9cbf-42ba33c9b98b/download,,"Laser Direct Metal Deposition (DMD) is an effective approach to manufacturing or
repairing a range of metal components. The process is a layer-by-layer approach to building
up a three dimensional solid object. The microstructure influences mechanical properties of
the deposited parts. Thus, it is important to understand the microstructural features of diode
laser deposited parts. This paper presents a microstructure analysis of a diode laser
deposited Ti-6Al-4V onto a Ti-6Al-4V substrate.",,,,,,
"['Doris, A.', 'Trujillo, L.', 'Godinez, Dana', 'Arrieta, E.', 'Wicker, R. B.', 'Gradl, P.', 'Medina, F.']",2023-03-30T15:58:19Z,2023-03-30T15:58:19Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117693', 'http://dx.doi.org/10.26153/tsw/44572']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'laser powder bed fusion (L-PBF)', 'Inconel 718', 'Microstructural  Characterization']",Microstructural Characterization of Laser Powder Bed Fusion (L-PBF) Additively Manufactured Inconel 718 for Aerospace Application,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f2f330fd-0995-409f-963c-5090d8540dba/download,,"Alloy 718 (Inconel 718) is used for aerospace applications because of its excellent corrosion 
resistance and mechanical properties. This alloy is particularly applicable in manufacturing 
components subjected to high temperatures in rocket engines, aero-engines, and gas turbines. 
Properties for this alloy when processing on systems from similar and different Laser Powder Bed 
Fusion (L-PBF) machines provide subtle differences due to process parameters, feedstock, and 
machine configurations.  A series of sixteen L-PBF AM Inconel 718 geometric feature build plates 
have been evaluated for microstructure using optical microscopy. This study presents the details 
of the microstructure analysis concerning geometry and different machine platforms. 
Microstructural investigations of these samples included average grain width measurement for all 
the X-Y and Y-Z build layers and are accompanied by process parameters and powder 
characterization. The present work concludes with a discussion on the importance of captured 
differences among builds to understand the practical limitations among AM platforms.",,,,,,
"['Basak, Amrita', 'Das, Suman']",2021-10-26T19:36:52Z,2021-10-26T19:36:52Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89567,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['MAR-M247', 'scanning laser epitaxy', 'microstructure', 'nickel-based superalloy']",Microstructural Characterization of MAR-M247 Fabricated Through Scanning Laser Epitaxy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d3aa7fb-b68e-4daa-bc91-ba0c7ba2e207/download,University of Texas at Austin,"Nickel-base superalloys are extensively used to produce gas turbine hot section components as
these alloys offer improved creep strength and higher fatigue resistance compared to other alloys
due to the presence of precipitate-strengthening phases such as Ni3Ti or Ni3Al (γ' phases) in the
normally face-centered cubic (FCC) structure of the solidified nickel. Although this second phase
is the main reason for the improvements in properties, presence of such phases also results in
increased processing difficulties as these alloys are prone to crack formation. In this work, we
demonstrate powder bed fusion-based additive manufacturing of MAR-M247 onto like-chemistry
substrates through scanning laser epitaxy (SLE). The SLE deposited MAR-M247 followed the
polycrystalline morphology of the underlying MAR-M247 substrate. Metallurgical continuity was
achieved across the entire deposit-substrate interface and the samples showed no warpage during
the laser processing across a broad range of processing parameters. Optical imaging, scanning
electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were carried out to
characterize the microstructural refinement in the SLE fabricated MAR-M247.","This work is
sponsored by the Office of Naval Research through grants N00014-11-1-0670 and N00014-14-1-
0658.",,,,,
"['Cima, M.J.', 'Lauder, A.', 'Khanuja, S.', 'Sachs, E.']",2018-04-19T18:17:45Z,2018-04-19T18:17:45Z,1992,Mechanical Engineering,doi:10.15781/T2W37MC63,http://hdl.handle.net/2152/64402,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Three Dimensional Printing', 'rapid prototyping', '3DP']",Microstructural Elements of Components Derived from 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f00d2d88-6b31-4ae6-9392-f16d0bf2b030/download,,,,,,,,
"['Niino, Toshiki', 'Haraguchi, Hisashi', 'Itagaki, Yutaro', 'Hara, Kentaro', 'Morita, Susumu']",2021-10-06T20:46:07Z,2021-10-06T20:46:07Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88440', 'http://dx.doi.org/10.26153/tsw/15377']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['preheat free processed parts', 'microstructural observation', 'laser sintering', 'plastic parts']",Microstructural Observation and Mechanical Property Evaluation of Plastic Parts Obtained by Preheat Free Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7f3d7d83-d0bc-4953-8889-4f7bd6cd5474/download,University of Texas at Austin,"Tensile test on preheat free (PF) processed part was performed it is shown that ultimate
strength is the same as that from conventional process when relative density is the
same. Microstructural observation showed that decomposition occurs during PF process.
Microstructure of PF processed part is similar to those of amorphous. It is indicated
that preheat free process can improve geometrical precision. PGA to which conventional
process cannot be applied was successful processed by PF. 
Tensile test on preheat free (PF) processed part was performed it is shown that ultimate
strength is the same as that from conventional process when relative density is the
same. Microstructural observation showed that decomposition occurs during PF process.
Microstructure of PF processed part is similar to those of amorphous. It is indicated
that preheat free process can improve geometrical precision. PGA to which conventional
process cannot be applied was successful processed by PF.",,,,,,
"['Sterling, Amanda J.', 'Torries, Brian', 'Shamsaei, Nima', 'Thompson, Scott M.', 'Daniewicz, Steven R.']",2021-10-20T21:26:12Z,2021-10-20T21:26:12Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89365,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Laser Engineered Net Shaping', 'fatigue', 'porosity', 'Ti-6Al-4V']",Microstructural Sensitive Fatigue Modeling of Additively Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7480ab9-aa56-4f83-a789-fe6fb10b85d7/download,University of Texas at Austin,"A common issue in powder-based Additive Manufacturing (AM) techniques is
porosity. While process parameters can be controlled to limit this occurrence, complete
elimination without post-processing is difficult. Because porosity can significantly affect fatigue
behavior of AM parts, it is important to understand and model this material trait. In this study, the
porosity in various Ti-6Al-4V specimens fabricated via Laser Engineered Net Shaping (LENS)
was determined prior to fatigue testing. Void distribution and morphology was
quantified. Fractography was performed to determine the specimen’s transition through crack
initiation and propagation stages. These results were used to calibrate a microstructure-sensitive
fatigue model for predicting the fatigue behavior of as-built and heat treated LENS Ti-6Al-4V.",,,,,,
"['Zhang, Yuanjie', 'Song, Bo', 'Zhang, Lei', 'Wang, Zhiwei', 'Shi, Yusheng']",2021-11-02T19:38:26Z,2021-11-02T19:38:26Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89877,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'amorphous alloys', 'crack']",Microstructure and Crack Distribution of Fe-Based Amorphous Alloys Manufactured by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6bc670eb-2d5b-47fe-be3e-0986e23b9d86/download,University of Texas at Austin,"In this study, Fe-based amorphous alloys with a length and width of 10 mm
and height of 6 mm were prepared by selective laser melting (SLM). X-ray diffraction,
Differential Thermal Analysis and Scanning Electron Microscope were used to
investigated the effect of scan space and strategy on the crystallization, microstructure,
crack distribution and density. The content of amorphous calculated by Differential
Thermal Analysis is up to 93%. There is an obviously trend to lower crack
distribution and higher density with an appropriate scan spaces and strategies. With
the increasing scan space, the density increased first, then gradually decreased, while
the crack decreased and then increasing with the scan space.",,,,,,
"['Bauer, T.', 'Spierings, A.B.', 'Wegener, K.']",2021-10-28T22:36:50Z,2021-10-28T22:36:50Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89719,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'additive manufacturing', 'anti-magnetic shielding alloy', 'magnetic properties']",Microstructure and Electro-Magnetic Properties of a Nickel-Based Anti-Magnetic Shielding Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c3acc281-9b8e-44fd-997e-029cc6df6a73/download,University of Texas at Austin,"Selective Laser Melting (SLM) is capable producing high performance parts e.g. for the
aerospace or turbine industry. Nonetheless there is a high potential in other sectors such as in the
electronic industry. For these applications, optimal properties of magnetic flux, coercive force
and hysteresis are required. An isotropic microstructure is favoured - a condition hardly achieved
by the SLM process. The SLM-processing window for a NiFe14Cu5Mo4 alloy is developed and
basic microstructure is presented. The electro-magnetic properties are measured using a specific
test bench allowing a direct comparison of the properties with a reference material. The results
are discussed with a specific focus on the effect of the microstructure on the industrial usage.",,,,,,
"['Zhang, Jingwei', 'Zhang, Yunlu', 'Liou, Frank', 'Newkirk, Joseph W.', 'Brown-Taminger, Karen M.', 'Seufzer, Walliam J.']",2021-10-20T21:39:23Z,2021-10-20T21:39:23Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89367,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'microstructures', 'hardness', 'Vickers hardness', 'Ti6Al4V-TiC']",A Microstructure and Hardness Study of Functionally Graded Materials Ti6Al4V/TiC by Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c79c5ec2-cb8c-473e-9024-be5a34848953/download,University of Texas at Austin,"Crack free functionally graded material (FGM) Ti6Al4V-TiC has been fabricated by laser
metal deposition (LMD) using TiC and Ti6Al4V powder which were premixed for different
ratios. This study focuses on the influence of laser processing parameters and TiC compositional
distribution on microstructure, Vickers hardness and phase. The microstructure is analyzed by
scanning electron microscopy (SEM), x-ray diffraction (XRD) and hardness tests. Primary
carbide, eutectic carbide and unmelted carbide are found in the deposit area. When laser power
increased, the primary and secondary dendrite arm spacing increased. The laser power and
scanning speed did not influence the Vickers hardness distribution significantly.",,,,,,
"['Zhang, M.N.', 'Zhou, X.L.', 'Zhu, W.Z.', 'Li, J.H.']",2021-11-02T19:30:06Z,2021-11-02T19:30:06Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89875,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'SLM', 'high-entropy alloy', 'densification', 'microstructure', 'microhardness']",Microstructure and Mechanical Behavior of AlCoCuFeNi High-Entropy Alloy Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3221e562-4504-46b6-9ea6-41595d73dfc4/download,University of Texas at Austin,"Additive manufacturing (AM) technique, such as selective laser melting (SLM) is a modern method for
materials fabrication and formation. In this study, AlCoCuFeNi HEA parts are fabricated by SLM using prealloyed powders prepared by atomization process. The effect of processing parameters on microstructures,
microhardness and compression property of SLM-fabricated HEA parts are systematically investigated. Results
show that input laser energy density involved in laser power and scan speed plays a significant role in the
densification behavior. A near-full 99.03% density is achieved as an energy density of 102.5 J/mm3
. The alloys
consist of simple body-centred cubic (BCC) structure and exhibit the highest microhardness up to 541.17 HV0.2
and compressive strength of 1621.1 MPa due to the BCC solid solution strengthening. The study reveals that
SLM is advantageous to produce the high-entropy alloy with high density, good mechanical properties and even
complicated shapes.",,,,,,
"['Bauer, T.', 'Dawson, K.', 'Spierings, A.B.', 'Wegener, K.']",2021-10-20T22:43:57Z,2021-10-20T22:43:57Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89380,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'additive manufacturing', 'Haynes®  230®', 'nickel base alloys', 'microstructure', 'mechanical properties']",Microstructure and Mechanical Characterisation of SLM Processed Haynes® 230®,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ccc369c2-3505-4be4-8be4-8e86cdac6b1d/download,University of Texas at Austin,"Selective Laser Melting (SLM) enables the production of complex near-net-shaped parts
especially out of difficult to machine Nickel based alloys like Haynes®
 230®. However, exact
knowledge of the SLM processing windows and the corresponding mechanical properties is
essential for a target-oriented part design as well as post process planning. Especially the high
cooling rate of the small weld pool characterizes the SLM process and is known to cause
material microstructures different to standard wrought or cast material.
Samples are built with different heat input levels and are analysed for their density, pore- and
crack sizes. Optical and scanning electron microscope (SEM) and electron backscatter diffraction
(EBSD) are used to characterize the material microstructure. Static tensile test samples were built
in either 0° or 90° orientation for the evaluation of mechanical properties at room temperature
and anisotropy as well as the influence of the different heat input levels are assessed.
It is shown that the alloy itself is well suited for the SLM process allowing the consolidation of
nearly defect free material with improved mechanical properties with regards of yield and
ultimate tensile strength compared to cast as well as wrought material.",,,,,,
"['Nastac, Mihaela', 'Klein, Rick Lucas Andrew']",2021-11-02T15:17:18Z,2021-11-02T15:17:18Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89826,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['microstructure', 'mechanical property', '316L', 'stainless steel', 'binder jetting', 'electron beam melting', 'selective laser melting']",Microstructure and Mechanical Properties Comparison of 316L Parts Produced by Different Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/540dffbb-f348-4382-aada-ec634337e724/download,University of Texas at Austin,"316L stainless steel alloy is well known for its corrosion resistance and combination of
strength and ductility. By using direct metal additive manufacturing, 316L parts can be produced
with volumes and complexity that were previously unachievable. Three of the major metal
additive manufacturing technologies – binder jetting, electron beam melting, and selective laser
melting – produce SS316L parts, but with different material properties and microstructures. This
paper will examine the microstructure and mechanical properties differences between parts
produced by the three methods and discuss recent advances to improve microstructure and
mechanical performance of metallic alloy parts produced by additive manufacturing.",,,,,,
"['Ahmad, Nabeel', 'Baig, Shaharyar', 'Ghiaasiaan, Reza', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-25T18:27:57Z,2023-01-25T18:27:57Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117294', 'http://dx.doi.org/10.26153/tsw/44175']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'laser powder bed fusion (L-PBF)', 'laser  powder directed energy deposition (LP-DED)', 'Inconel 718', 'grain size', 'tensile properties']",Microstructure and mechanical properties of additively manufactured  Inconel 718: A comparative study between L-PBF and LP-DED,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ceea1ffb-21ae-43c3-abca-77c49e90ecab/download,,"This study aims to characterize the microstructure and mechanical properties of 
Inconel 718 fabricated using two different additive manufacturing processes: laser 
powder bed fusion (L-PBF) and laser powder directed energy deposition (LP-DED). 
Similar heat treatments (HTs) including stress-relief (1065ºC for 1.5 hr), hot isostatic 
pressing (1162ºC under 100 MPa isostatic pressure of Ar gas for 3 hr), solution 
annealing (1065ºC for 1 hr), and two-step ageing (760ºC for 10 hr + 650ºC for 10 hr) 
are applied to both batches. Scanning electron microscopy is utilized to characterize 
microstructural evolution during each step of HTs for both samples. Tensile tests are 
performed to evaluate the mechanical properties at room temperature. Elongation to 
failure of L-PBF specimens is measured to be 16% lower than that of the LP-DED 
ones, while the ultimate tensile and yield strengths of L-PBF specimens are, 
respectively, 9% and 6% higher, compared to the LP-DED ones. The differences in 
tensile properties between two specimens are explained using microstructural and 
fracture surfaces analysis.",,,,,,
"['Muhammad, Muztahid', 'Gusain, Rukesh', 'Ghiaasiaan, Seyed R.', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2023-01-25T18:22:33Z,2023-01-25T18:22:33Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117293', 'http://dx.doi.org/10.26153/tsw/44174']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Haynes 230', 'laser powder bed fusion', 'laser powder directed  energy deposition', 'tensile properties']",Microstructure and Mechanical Properties of Additively Manufactured Haynes 230: A Comparative Study of L-PBF vs. LP-DED,Conference paper,https://repositories.lib.utexas.edu//bitstreams/99cfdd18-515e-4cc7-a2de-d207f43ff657/download,,"This study investigates the microstructure and room temperature mechanical properties of 
Haynes 230 fabricated via laser powder bed fusion (L-PBF) and laser powder directed energy 
deposition (LP-DED). Both L-PBF and LP-DED specimens underwent similar multiple-step heat 
treatments (HT): stress-relieving (1066°C for 1.5 hours), followed by hot isostatic pressing (at 1163°C 
and 103 MPa for 3 hours), and solution annealing (1177°C for 3 hours). Microstructural analysis was 
conducted employing a scanning electron microscope. Uniaxial tensile tests at room temperature were 
conducted to evaluate the mechanical properties. The change in microstructures after HT and tensile 
results for both L-PBF and LP-DED specimens were comparable. Upon HTs, the micro-segregation 
and dendritic microstructure observed in non-heat treated conditions were almost fully dissolved, and 
carbide phases (M6C/M23C6) formed within grain interiors and grain boundaries in both L-PBF and 
LP-DED specimens. Finally, the failure mechanisms under tensile load have been studied and 
compared by fractography.",,,,,,
"['Ahmad, Nabeel', 'Ghiaasiaan, Reza', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima']",2024-03-26T16:38:35Z,2024-03-26T16:38:35Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124363', 'https://doi.org/10.26153/tsw/50971']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser powder bed fusion', 'laser powder directed energy deposition', 'Haynes 282', 'grain size', 'tensile properties']",Microstructure and Mechanical Properties of Additively Manufactured Haynes 282: A Comparative Analysis between Laser Powder Bed Fusion and Laser Powder Directed Energy Deposition Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9684a77-93c3-480b-91be-ee58d82d548d/download,University of Texas at Austin,"This study compares the microstructure and tensile properties of Haynes 282 fabricated using laser powder
bed fusion and laser powder directed energy deposition. Both sets underwent stress-relieving, followed by hot
isostatic pressing, and the standard double aging heat treatment. Tensile testing was conducted at room
temperature on specimens fabricated with both technologies to evaluate and compare their tensile behaviors.
Results show that the ultimate tensile and yield strengths of laser powder bed fused specimens were 18% and
57% higher, respectively than those of laser powder directed energy deposited ones, whereas the elongation to
failure was similar in both. The difference in strengths is attributed to the differences in the size of γ' precipitates
and grains, i.e., those in the laser powder directed energy deposited specimens being larger, whereas similar
elongation to failure is attributed to the carbide debonding dominating the fracture mechanism in both batches.",,,,,,
"['Yasa, E.', 'Kempen, K.', 'Kruth, J.-P.']",2021-09-30T15:32:25Z,2021-09-30T15:32:25Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88264', 'http://dx.doi.org/10.26153/tsw/15205']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'maraging steel 300', 'heat treatments', 'microstructures', 'mechanical properties']",Microstructure and Mechanical Properties of Maraging Steel 300 After Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be324be9-85bc-4e41-9ca2-79fad6c89d73/download,University of Texas at Austin,"Selective laser melting (SLM) is an additive manufacturing process for the direct fabrication of
prototypes, tools and functional parts. The process uses a high intensity laser beam to selectively
fuse fine metal powder particles together in a layer-wise manner by scanning cross-sections
generated from a three-dimensional CAD model. The SLM process is capable of producing near
fully dense functional products without almost any geometrical limitation and having mechanical
properties comparable to those produced by conventional manufacturing techniques. There is a
wide range of materials that are suitable to be processed by SLM including various steels, Ti, Al
and CoCr alloys. Being one of these materials, maraging steel 300 (18Ni-300) is an iron-nickel
steel alloy which is often used in applications where high fracture toughness and strength are
required or where dimensional changes have to remain at a minimal level, e.g. aircraft and
aerospace industries for rocket motor castings and landing gear or tooling applications. To
achieve its superior strength and hardness, maraging steel, of which the name is derived from
‘martensite aging’, should be treated with an aging heat treatment. In this study, the effect of the
SLM parameters (scan speed and layer thickness) on the obtained density, surface quality and
hardness of maraging steel 300 parts is investigated. Moreover, various aging heat treatments
(different combinations of duration and maximum temperature) are applied on the SLM parts to
achieve high hardness values. The mechanical testing of maraging steel 300 specimens produced
by SLM and treated with an appropriate aging treatment is accomplished by impact toughness
and tensile tests and compared to the results obtained using conventional production techniques.
Additionally, the microstructures of as-built and heat treated parts are investigated.",,,,,,
"['Feng, Shaw C.', 'Jones, Albert T.', 'Lu, Yan']",2021-12-01T22:50:05Z,2021-12-01T22:50:05Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90644', 'http://dx.doi.org/10.26153/tsw/17563']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['data alignment', 'data registration', 'microstructure', 'mechanical property', 'additive manufacturing']",Microstructure and Mechanical Test Data Alignment for Additive Manufacturing Data Registration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/548d2741-fd42-444b-808a-315bed1cae43/download,University of Texas at Austin,"Melt pool monitoring, microstructure, and mechanical property data are becoming
increasingly available and important in additive manufacturing (AM). These data along with data
analytics tools can be used to ensure the part’s quality and accelerate the qualification process. A
major impediment to correlating these types of data is that they are obtained in different local
coordinate systems. To establish the required process-microstructure-property relationships, these
data must also be aligned with other build data such as build commands. This paper proposes an
innovative data registration procedure to correlate and organize these different types of data.",,,,,,
"['Zhang, Yunlu', 'Zhang, Jingwei', 'Liou, Frank', 'Newkirk, Joseph']",2021-10-20T21:45:09Z,2021-10-20T21:45:09Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89369,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Ti alloy composites', 'TiB-reinforced composites', 'laser metal deposition']",Microstructure and Property of TiB-Reinforced Ti Alloy Composites by Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a3d903a-c392-4768-b69b-10740e1ba825/download,University of Texas at Austin,"TiB-reinforced Ti alloy composites have been laser deposited with pre-alloyed Ti-6Al4V-1B powder. The microstructure of the as-deposited and heat treated composites have been
characterized in detail using scanning electron microscope (SEM). A homogeneous dispersion
of needle-like TiB precipitates is formed in the Ti-6Al-4V α/β matrix. TiB precipitates promote
formation of small near equaxed α/β grain after β annealing process. The micro-hardness of the
laser deposited composites increase 20-30% with 5 vol. % TiB precipitates compared to
unreinforced Ti-6Al-4V deposits.",,,,,,
"['Brooks, J.', 'Robino, C.', 'Headley, T.', 'Goods, S.', 'Griffith, M.']",2019-03-15T16:22:33Z,2019-03-15T16:22:33Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73688', 'http://dx.doi.org/10.26153/tsw/830']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['LENS', 'metallurgical']",Microstructure and Property Optimization of LENS Deposited H13 Tool Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/37e93221-1903-4fc6-bb22-7cfca933e612/download,,"Direct laser metal deposition is a means of near net shape processing that offers a number
of advantages including rapid prototyping and small lot production. With the LENS (Laser
Engineered Net Shape) process [Ref 1], parts are fabricated by creating a laser melted pool into
which particles are injected. Fabrication proceeds by moving the work piece, thereby building
the structure line by line and layer by layer. In this manner a wide variety of geometries and
structures can be fabricated. During fabrication, a complex thermal history is experienced in
different  regions of the build. These thermal histories include remelting and numerous lower
temperature thermal cycles. Furthermore, the use of a finely focused laser to form the rapidly
traversing pooL can result in relatively high solidification velocities and cooling rates.
Previous work has developed LENS as an advanced manufacturing tool rather than
exploiting its potentially unique attributes: real time control of microstructure, tailored material
properties at different part locations, the production of graded structures, etc. Very often,
however, material properties are not significantly different than those of wrought materials.
The. goal of this program is to exploit the unusual thermal environment experienced during
fabrication, and the ability to design and vary alloy composition. In this paper we describe this
approach using H13 tool steel in which only the thennal fields are varied through changing
process parameters to achieve desired properties.",,,,,,
"Kumar, S.",2020-03-10T17:41:21Z,2020-03-10T17:41:21Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80239', 'http://dx.doi.org/10.26153/tsw/7258']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,Microstructure and Wear of SLM Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9cdb31de-3ee1-47a9-8ab1-104bb15eb2da/download,,,,,,,,
"['Murr, L.E.', 'Gaytan, S.M.', 'Ramirez, D.A.', 'Martinez, E.', 'Martinez, J.L.', 'Hernandez, D.H.', 'Machado, B.I.', 'Medina, F.', 'Wicker, R.B.']",2021-09-30T14:53:02Z,2021-09-30T14:53:02Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88260', 'http://dx.doi.org/10.26153/tsw/15201']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['materials with controlled microstructural architecture', 'microstructure architecture development', 'additive manufacturing', 'electron beam melting', 'metals', 'alloys', 'solid free-form fabrication']",Microstructure Architecture Development in Metals and Alloys By Additive Manufacturing Using Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fe50d5bc-4f2b-439a-9089-441921509690/download,University of Texas at Austin,"The concept of materials with controlled microstructural architecture (MCMA) to
develop and fabricate structural materials with novel and possibly superior properties and
performance characteristics is a new paradigm or paradigm extension for materials science and
engineering. In the conventional materials science and engineering paradigm, structure
(microstructure), properties, processing, and performance features are linked in the development
of desirable materials properties and performance through processing methodologies which
manipulate microstructures. For many metal or alloy systems, thermomechanical treatment
combining controlled amounts of plastic deformation with heat treatment or aging cycles can
achieve improved mechanical properties beyond those attainable by conventional processing
alone (such as rolling or forging for example) through controlled microstructure development. In
this paper we illustrate a new concept involving the fabrication of microstructural architectures
by the process development and selective manipulation of these microstructures ideally defining
material design space. This allows for the additional or independent manipulation of material
properties by additive manufacturing (AM) using electron beam melting (EBM). Specifically we
demonstrate the novel development of a carbide (M23C6) architecture in the AM of a Co-base
alloy and an oxide (Cu2O) precipitate-dislocation architecture in the AM of an oxygen-containing Cu. While more conventional processing can produce various precipitate
microstructures in these materials, EBM produces spatial arrays of precipitate columns or
columnar-like features often oriented in the build direction. These microstructural architectures
are observed by optical microscopy and scanning and transmission electron microscopy.
Prospects for EBM architecture development in precipitation-hardenable Al alloys is also
discussed. In the EBM build process using precursor powders, the electron beam parameters
(including beam focus, scan speed and sequencing) produce localized, requisite thermodynamic
regimes which create or organize the precipitate-related spatial arrays. This feature demonstrates
the utility of AM not only in the fabrication of complex components, but also prospects for
selective property design using CAD for MCMA development: a new or extended processing-microstructure-property-performance paradigm for materials science and engineering in
advanced manufacturing involving solid free-form fabrication (SFF).",,,,,,
"['Li, Xiaoxuan', 'Wang, Jiwen', 'Augustine, Alvin', 'Shaw, Leon L.', 'Marcus, Harris L.']",2019-10-10T17:08:49Z,2019-10-10T17:08:49Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76174', 'http://dx.doi.org/10.26153/tsw/3263']",eng,2001 International Solid Freeform Fabrication Symposium,Open,"['De', 'Densification']",Microstructure Evaluation for Laser Densification of Dental Porcelains,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6f46b07e-c857-4984-8778-d8e603c43751/download,,"The feasibility of dental restorations has been investigated using a multi-materials laser
densification (MMLD) process, where dental alloy and porcelain powders are laser densified layer
by layer to form solid bodies. The present study focuses on the densification behavior of dental
porcelain powders in response to a moving laser source. Effects of the laser processing temperature
and the green density of the powder bed on microstructure, distortion, macro-cracks, porosities and
phase contents of the laser densified porcelain have been investigated. The condition to generate
continuous porcelain bodies from powder compacts have also be studied. It is found that the
geometry, composition and density of densified porcelain bodies are strongly affected by the laser
processing temperature and the green density of the powder compact.",,,,,,
"['Avateffazeli, Maryam', 'Khan, Md Faysal', 'Shamsaei, Nima', 'Haghshenas, Meysam']",2023-01-23T13:56:51Z,2023-01-23T13:56:51Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117278', 'http://dx.doi.org/10.26153/tsw/44159']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['A205', 'Al-Cu-Mg-Ag-TiB2', 'laser powder bed fusion', 'fatigue', 'T7 aging']","Microstructure,  Mechanical, and Fatigue Properties of a Laser Powder Bed Fused Al-Cu-Mg-Ag-Ti-B (A205) Alloy",Conference paper,https://repositories.lib.utexas.edu//bitstreams/879d1293-5a77-4fd3-8d08-c1dc4bc7df78/download,,"This paper aims at assessing the effect of heat treatment on fatigue behavior of a novel 
laser-powder-bed-fusion (L-PBF) fabricated Al-Cu-Mg-Ag-Ti-B alloy, known as A205. To this 
end, L-PBF samples were heat-treated including (i) stress-relieving, and (ii) T7 stabilizing over-
aging. Upon printing and post-heat treatments, advanced microstructural characterizations, 
mechanical property measurements and force-controlled fatigue performance studies were 
conducted on the samples, systematically. The findings in this paper present useful information 
for the selection of appropriate heat treatment conditions, to facilitate control of the fatigue 
behavior in the L-PBF A205 material, which is of great significance for their high-demanding 
applications in aerospace sectors.",,,,,,
"['Zimbeck, Walter', 'Pope, Matthew', 'Rice, R.W.']",2018-11-14T20:49:15Z,2018-11-14T20:49:15Z,1996,Mechanical Engineering,doi:10.15781/T24M91W7C,http://hdl.handle.net/2152/70265,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['UV flood lamp', '3D printing', 'SFF']",Microstructures and Strengths of Metals and Ceramics made by Photopolymerbased Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0bd8cbd7-647c-4a60-b324-00eadb1a0a33/download,,"Metal and ceramic flexure specimens were fabricated using a photopolymer-based rapid
prototyping technique. Photosensitive resins (inks) were produced by dispersing 50 - 55 vol%
metal or ceramic powders in a photopolymer resin. Laminates 0.2"" thick were built up by repeated
application oflayers 3 - 10 mils thick followed by curing under a UV flood lamp with photomasks.
The layered samples were thermally processed to remove the photopolymer binder and sintered to
high density. Densities, microstructural characterization and flexure strengths are reported for
silicon nitride, alumina, zirconia, stainless steel, and tungsten.",,,,,,
"['Buls, Sam', 'Vleugels, Jef', 'Van Hooreweder, Brecht']",2021-11-16T15:08:23Z,2021-11-16T15:08:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90307', 'http://dx.doi.org/10.26153/tsw/17228']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['technical ceramics', 'ceramics', 'direct processing', 'microwave assisted selective laser melting']",Microwave Assisted Selective Laser Melting of Technical Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a047b73f-844e-44b4-8992-7a35c8f33700/download,University of Texas at Austin,"Direct processing of near fully dense technical ceramics is not possible with conventional additive
manufacturing (AM) processes due to the very high temperatures that are required. Therefore, indirect AM
approaches are often used. These indirect processes show great potential but require extensive post processing
(e.g. debinding and sintering) leading to shrinkage, limited geometrical accuracy and eventually limiting overall
part quality. To overcome these limitations, this paper presents a novel Microwave Assisted Selective Laser
Melting process that enables direct processing of technical ceramics.",,,,,,
"['Clark, N.', 'Lacan, F.', 'Porch, A.']",2021-11-02T18:27:59Z,2021-11-02T18:27:59Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89860,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['microwave', 'nylon', 'perturbation', 'permittivity', 'powder', 'polyamide', 'laser sintering']",Microwave Measurements of Nylon-12 Powder Ageing for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93b2b36e-6c53-48ea-888d-f66f325f81b3/download,University of Texas at Austin,"With repeated recycling, nylon powders used in Selective Laser Sintering are known to
degrade and ultimately cause mechanical performance and surface finish deterioration in produced
parts. In order to maintain consistent production and to reduce cost by minimising waste powder,
it is desirable to monitor this degradation. However, any techniques used must be inexpensive,
quick and simple in order to maintain industrial relevance; dielectric measurements by microwave
cavity perturbation can offer these advantages. Here, samples are taken from a working SLS
machine and their permittivity measured using microwave cavity perturbation operating around 2.5
GHz. A 2% reduction in effective dielectric constant and an 8% reduction in effective dielectric
loss is observed between new powder and recycled feedstock. Furthermore, in-situ measurements
simulating build chamber conditions show a similar trend.",,,,,,
"['Krishnanand, L.', 'Manmadhachary, A.', 'Ravi Kumar, Y.']",2021-10-18T20:58:05Z,2021-10-18T20:58:05Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89244,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['CT', 'partial volume effect', 'volumetric error', 'CT image construction', 'ANOVA']",Minimization of Volumetric Errors in CAD Medical Models Using 64 Slice Spiral CT Scanner,Conference paper,https://repositories.lib.utexas.edu//bitstreams/845fb874-dfeb-4c5c-9e7e-121d89a70d44/download,University of Texas at Austin,"Sixty four slice spiral Computed Tomography (CT) scanner is one of the advanced CT
scanners to capture the large volume of tissues and improved longitudinal resolution. The CT
images are used to develop a 3-Dimensional (3D) Computer Aided Design (CAD) medical
model. While developing a 3D CAD medical model volumetric errors occur due to partial
volume or volume averaging effect. In order to study, various CT image construction parameters
were considered to minimize the volumetric errors in 3D CAD medical models, a human dry
mandible has been selected as a phantom. A Taguchi technique was used to find optimal CT
image construction parameters. A L9 orthogonal array was used to optimize the CT image
construction parameters constituting slice thickness, slice increment and Field of View (FOV)
while performing CT image construction. The resultant optimal parameters are scrutinized using
analysis of variance (ANOVA) method for its influence on the CT image construction. In this
work, it has been found that there is a volumetric error of a 3D CAD medical model (STL file)
from CT images of a dry mandible was 1978 mm3
(6.11%).",,,,,,
"['Chan, C K', 'Tan, S T']",2019-03-12T16:13:52Z,2019-03-12T16:13:52Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73594', 'http://dx.doi.org/10.26153/tsw/736']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['bounding box', 'iterative method']",A Minimum Bounding Box Algorithm and its Application to Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e6ef6c2-b191-4947-b32e-dc46d5f49bb6/download,,"This paper describes a method for determining the minimum bounding box of an
arbitrary solid. The method simplifies the complex three-dimensional problem by projecting
the solid onto the three principal planes and makes use ofthe projected contours for analysis.
The orientations of the contours are determined by rotating them within a specific angle
range. These orientations are then used to approximate the orientation of the solid so that its
bounding box volume is minimised.",,,,,,
"['Grant, Lynnora O.', 'Alameen, Magdi B.', 'Carazzone, J. Reid', 'Higgs, C. Fred III', 'Cordero, Zachary C.']",2021-11-09T14:42:05Z,2021-11-09T14:42:05Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90083', 'http://dx.doi.org/10.26153/tsw/17004']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'binder jetting', 'reactive binder', 'distortion', '3D printing', 'ceramics']",Mitigating Distortion During Sintering of Binder Jet Printed Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/915136a3-3415-4297-ba94-0f24787c9418/download,University of Texas at Austin,"Sintering increases the strength of binder jet 3D printed green bodies through densification,
but with the potential cost of distortion due to creep. In this work, we determine how a reactive
binder affects such distortion during sintering of titanium dioxide green bodies. The binder
decomposes to form nanocrystalline interparticle necks during the early stages of the sintering
process. We first characterize the decomposition of the reactive binder through thermogravimetry,
differential scanning calorimetry, and x-ray diffraction. Next, we elucidate the effect of this
precursor on the shrinkage of cylindrical parts using dilatometry experiments, and observe the
deflection of sintering beams using in situ imaging. These experiments show that the precursor
dramatically suppresses creep during sintering, demonstrating a potential solution for increasing
the dimensional accuracy of the binder jet 3D printing process.",,,,,,
"['Marques, Lucas Galvan', 'Williams, Robert Austin', 'Zhou, Wenchao']",2021-11-04T14:41:46Z,2021-11-04T14:41:46Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89972,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['mobile 3D printer', 'filament extrusion printhead', 'Internet', 'cooperative 3D printing']",A Mobile 3D Printer for Cooperative 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2c0501ab-203a-4e74-b19d-63e3b7c7460b/download,University of Texas at Austin,"Cooperative 3D printing is an emerging technology that aims to provide scalability to 3D
printing by enabling thousands of printhead-carrying mobile robots to cooperate on a single
printing job and to integrate pre-manufactured components during the 3D printing process.
At the core of the cooperative 3D printing platform is a mobile robot that can carry different
printhead or a gripper. In this paper, we present a mobile 3D printer with a filament
extrusion printhead that can be controlled over the Internet. First, we designed a compact
mobile 3D printer with an extrusion printhead and four omnidirectional wheels. A wireless
communication interface is also developed to send commands to and receive information
from the mobile 3D printer. Successful prints have been demonstrated with two developed
mobile 3D printers printing cooperatively, which shows the promise of cooperative 3D
printing.",,,,,,
"['Asiabanpour, B.', 'Um, D.', 'Sriraman, V.', 'Tseng, A.', 'Mata, J.', 'Wahed, N.']",2020-02-20T19:23:47Z,2020-02-20T19:23:47Z,8/23/05,Mechanical Engineering,,https://hdl.handle.net/2152/80041,eng,2005 International Solid Freeform Fabrication Symposium,Open,Mobile Paving System,Mobile Paving System (MPS): A New Large Scale Freeform Fabrication Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/071942f4-ab67-4a91-84e9-c2822b0ff62d/download,,"In the last decade, significant opportunities for automation have been identified in the area of
construction. Soaring labor and material costs have driven multiple research efforts in
construction automation. In this paper, we present a novel means for construction automation
that involves the fusion of the rapid prototyping, controls and mechatronics technologies. The
resultant autonomous construction mechanism has been designed for commercial applications.
Mobile Paving System (MPS) is a new freeform fabrication process which is capable of rapidly
producing variable profiles such as curbs and sidewalks out of materials like cement and asphalt.
Path generation and guidance of the construction operation is controlled by a mobile robot. This
article presents an overview of research and development efforts that are aimed at establishing
the feasibility and the potential of the process.",,,,,,
"['Steck, Jason', 'Morales-Ortega, Rolando', 'Currence, Jacob', 'Zhou, Wenchao']",2021-11-08T22:48:24Z,2021-11-08T22:48:24Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90063', 'http://dx.doi.org/10.26153/tsw/16984']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'cooperative 3D printing', 'robot gripper', 'hybrid production']",A Mobile Robot Gripper for Cooperative 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9805dc4-ced4-4c09-b1ba-2ef94b14dcc8/download,University of Texas at Austin,"Cooperative 3D printing is an emerging technology that aims to overcome several limitations of
contemporary 3D printing (e.g., print size, cost, complexity) by allowing multiple mobile 3D
printers (or printhead-carrying mobile robots) to work simultaneously on a single print job. In
particular, one challenge of 3D printing is the inability to incorporate pre-manufactured
components in a structure without human intervention. In this paper, we present a mobile robot
gripper that can work with other mobile 3D printers to pick and place pre-manufactured
components into a 3D printed structure during the printing process. First, we designed a simple
gripper using a rack and pinion actuator that can be driven by a single stepper motor like a regular
extrusion printhead. Next, a mobile robot gripper is developed with the designed gripper
mechanism. Finally, we tested the mobile robot gripper for picking and placing objects using G-code commands. Results show the mobile robot gripper can successfully pick and place pre-manufactured components into a 3D printed structure. This development will potentially enable
autonomous hybrid manufacturing that combines 3D printing and traditional manufacturing to
improve the quality and capability for manufacturing complex products.",,,,,,
"['Pribe, Joshua D.', 'West, Brian M.', 'Gegel, Michelle L.', 'Hartwig, Troy', 'Lunn, Toby', 'Brown, Ben', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Kinzel, Edward C.']",2021-10-26T18:13:52Z,2021-10-26T18:13:52Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89547,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['modal response', 'validation technique', 'metal parts', 'selective laser melting', 'frequency response function', 'FRF']",Modal Response as a Validation Technique for Metal Parts Fabricated with Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6129fd15-cc52-46d3-b18c-24c72ce385c1/download,University of Texas at Austin,"This paper investigates modal analysis as a validation technique for additively manufactured parts. The Frequency Response Function (FRF) is dependent on both the geometry and the
material properties of the part as well as the presence of any defects. This allows the FRF to serve
as a “fingerprint” for a given part of given quality. Once established, the FRF can be used to
qualify subsequently printed parts. This approach is particularly attractive for metal parts, due to
the lower damping as well as use in high-value applications where failure is unacceptable. To
evaluate the efficacy of the technique, tensile specimens are printed with a Renishaw AM250, the
modal response of these parts is characterized prior to tensile testing, and the FRFs are compared
to their engineering metrics for parts printed with both nominal and off-nominal parameters. Numerical modeling is used to understand the modal structure, and the possibility of defect prognosis
is also explored by comparing the measured response to simulation results.",,,,,,
"['Chahal, Vedant', 'Taylor, Robert M.']",2021-11-09T19:46:34Z,2021-11-09T19:46:34Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90144', 'http://dx.doi.org/10.26153/tsw/17065']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['residual stress', 'maraging steel 300', 'model development', 'laser metal 3D printing', 'selective laser melting', 'design of experiments']",Model Development for Residual Stress Consideration in Design for Laser Metal 3D Printing of Maraging Steel 300,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eda19017-2fd2-4e9f-9a5b-33ebdbaee331/download,University of Texas at Austin,"Design optimization of laser metal 3D printed structural components requires prediction of
build-process induced residual stresses that vary with part geometry and affect distortion and support requirements during the build. Finite element residual stress state evaluation is not feasible
within the computational constraints of iterative optimization. Alternatively, a simplified theoretical model is presented for predicting the residual stresses induced during Selective Laser Melting
of maraging steel. Furthermore, a Design of Experiments (DOE) approach is implemented to verify the theoretical model and develop a response surface suitable for design optimization. The DOE
uses cantilever geometry with length, thickness, and fillet radius as variables and shows overhang
length to have the greatest influence on residual stresses. Geometries with high stiffness lead to
lower deformations and tend to retain high stresses. The presented model can predict the trend of
residual stresses for different geometries and can be used in shape optimization.",,,,,,
"['Dwivedi, Rajeev', 'Zekovic, Srdja', 'Kovacevic, Radovan']",2020-02-24T14:56:38Z,2020-02-24T14:56:38Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80076', 'http://dx.doi.org/10.26153/tsw/7097']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,A Model for Error Propagation in the Surface Profile for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/60d45401-1f0c-4cbe-b33e-05f57bfc84b0/download,,,,,,,,
"['Sun, Ming-shen', 'Nelson, Christian', 'Beaman, Joseph J.', 'Barlow, Joel J.']",2018-04-12T18:22:09Z,2018-04-12T18:22:09Z,1991,Mechanical Engineering,doi:10.15781/T29W09G38,http://hdl.handle.net/2152/64279,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Powder bed', ""Frenkel's model"", 'SSL']",A Model for Partial Viscous Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5bfa0356-d008-4cd1-8332-67a5d0f3b3d9/download,,"A mathematical model describing the sintering rate of a viscous material powder
bed is presented. This model assumes that the powder bed is composed of cubic
packed, equal-size spherical particles. The sintering rate equation is derived in
terms of a unit cell dimension or the relative density of a powder bed. A
mathematical factor, fraction of sintering, is introduced to explain the
phenomena of partial sintering. Key words: model, viscous sintering.",,,,,,
"['Watanabe, N.', 'Shofner, M.L.', 'Treat, N.', 'Rosen, D.W.']",2021-11-01T22:50:36Z,2021-11-01T22:50:36Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89788,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['residual stress', 'part warpage', 'polypropylene', 'material extrusion']",A Model for Residual Stress and Part Warpage Prediction in Material Extrusion with Application to Polypropylene,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3af82ce8-1e6e-44ad-8b85-b769385adbcb/download,University of Texas at Austin,"The layer-by-layer fabrication procedure causes residual stresses to accumulate due to the
repetition of heating and cooling during the material extrusion process. In this study, residual
stress and part warpage of a polypropylene copolymer are investigated. The effects of adjusting
process variable settings, such as deposition temperature, deposition speed, and layer height, on
part warpage are analyzed computationally and experimentally. Material extrusion process
simulation models that are capable of predicting the temperature distributions, deposited filament
shapes, and residual stresses of fabricated parts have been developed. These models are used to
predict the warpages and deformations of the fabricated parts; these predictions are compared
with experimental results to evaluate the models’ efficacy. Insights are gained on the effects of
particulate inclusions on the residual stress and warpage behaviors of polypropylene copolymer.",,,,,,
"['Sui, Chao', 'Zhou, Wenchao']",2023-01-27T14:18:15Z,2023-01-27T14:18:15Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117337', 'http://dx.doi.org/10.26153/tsw/44218']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['piezo inkjet', 'printing speed', 'drop-on-demand (DOD)', 'driving signal', 'model']",A Model for the Effects of Driving Signal on Piezoelectric Inkjet Printing Speed,Conference paper,https://repositories.lib.utexas.edu//bitstreams/085fe5dd-7d67-4bf3-b4ed-669263dc7aa0/download,,"Piezo drop-on-demand (DOD) inkjet is a non-contact and direct forming technique for 
pattern fabrication, which has been widely used in additive manufacturing and other 
industrial applications. It is known that the ink properties and the waveform of the driving 
signal play a significant role in droplet ejection behavior. In this paper, we present a model 
for the droplet formation dynamics from a single nozzle with a bipolar driving signal, which 
provides a quantitative relationship between the waveform of the driving signal and the 
average jetting velocity at the nozzle exit, droplet ejection frequency, droplet volume, and 
printing speed. An experimental setup is developed for calibration and validation of the 
model. Results show the model agrees well with experiments and can be used to predict 
inkjet printing speed based on the parameters of the driving signal.",,,,,,
"['Das, Suman', 'Chung, Haseung']",2019-10-18T15:28:40Z,2019-10-18T15:28:40Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76239', 'http://dx.doi.org/10.26153/tsw/3328']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sintering,A Model of Laser-Powder Interaction in Direct Selective Laser Sintering of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b50adf57-fc89-4de0-a681-27d73a793839/download,,"We present a simple one-dimensional model that describes the physical mechanisms of
heat transfer, melting and resolidification taking place during and after the interaction of a laser
beam with a bed of pure metal powder. The physical model describing this situation is based on
the classical Stefan problem with appropriately chosen boundary conditions to reflect direct
selective laser sintering of metals. A numerical model based on the finite volume method is
developed to perform computations for two beam diameters, three beam speeds and for constant,
step and ramp laser power input profiles. The results of these computations show the influence of
laser beam diameter, laser power input rate and input duration on the melt interface velocity and
location, and temperature. Scaling laws for time to reach maximum melt depth and total meltresolidification time are derived. Comparisons of the temperature histories for the three power
input profiles are described.",,,,,,
"['Klosterman, Donald', 'Chartoff, Richard', 'Flach, Lawrance', 'Bryant, Eric']",2019-09-23T16:49:50Z,2019-09-23T16:49:50Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75967', 'http://dx.doi.org/10.26153/tsw/3066']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Fabrication,Model-Based Control of Cure Distribution in Polymer Composite Parts Made by Laminated Object Fabrication (LOF) 409,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fd4471c3-4bbf-408a-bd0a-0b818e0c33c7/download,,"A mathematical heat transfer model was used to investigate process control strategies for making thermoset polymer composite materials by Laminated Object Fabrication (LOF). The temperature of the laminator was manipulated in order to control the uniformity and overall level of cure through the thickness of a 20-layer part. When the laminator temperature was held constant throughout the LOF build process, as is normally the case in practice, the model predicted that the resulting panel would have a steep cure gradient from top to bottom. This was considered to be undesirable. The model was then used in conjunction with an optimization algorithm to determine a temperature program for the laminator which would result in panels with a more desirable spatial cure profile (i.e. constant). Computer model simulations demonstrated that it should be feasible to control both the level and distribution of cure in thermoset composite panels layed-up with LOF by simply manipulating the laminator temperature with simple and realistic heating schedules.",,,,,,
"['Mignatti, M.A.', 'Campbell, M.I.', 'Ruizpalacios, R.', 'Wood, K.L.', 'Beaman, J.J.']",2019-11-21T18:19:21Z,2019-11-21T18:19:21Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78555', 'http://dx.doi.org/10.26153/tsw/5611']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Direct-Write,"Modeling and Characterization of a Novel, Low-Cost, Direct-Write Waveguide",Conference paper,https://repositories.lib.utexas.edu//bitstreams/69808ec2-00d6-4485-9e3b-9257373a55fe/download,,"Both the current long-term telecommunication trends toward optical networking and the
recent growth in information bandwidth have pushed the necessity for improved optical
communications. Our fabrication approach, which leverages our expertise in solid
freeform fabrication in conjunction with sol-gel technology, has advantages over these
other methods because of the inherent benefits of using a direct-write philosophy, such as
design flexibility and minimal post-processing. However, fabrication of such novel
optical components requires extensive knowledge of their light guidance capabilities.
This paper will show the technical issues involved in both modeling and characterizing
small optical components fabricated by locally densifying sol-gels in a modified directwrite process.",,,,,,
"['Basak, Amrita', 'Acharya, Ranadip', 'Das, Suman']",2021-10-21T18:09:07Z,2021-10-21T18:09:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89414,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['microstructure evolution', 'single-crystal alloys', 'scanning laser epitaxy']",Modeling and Characterization of Microstructure Evolution in Single-Crystal Superalloys Processed through Scanning Laser Epitaxy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/33ee570e-19fc-41a8-b58b-3bd91baefadb/download,University of Texas at Austin,"This paper focuses on microstructure evolution in single-crystal alloys processed through
scanning laser epitaxy (SLE); a metal powder-bed based additive manufacturing technology
aimed at the creation of equiaxed, directionally-solidified or single-crystal structures in nickel-base superalloys. Galvanometer-controlled movements of the laser and high-resolution raster
scanning result in improved control over the melting and solidification processes in SLE.
Characterization of microstructural evolution as a function of the complex process physics in
SLE is essential for process development, control and optimization. In this paper an ANSYS
CFX based transient flow-thermal model has been developed to simulate microstructure
characteristics for single-crystal superalloys such as CMSX-4 and René N5. Geometrical
parameters and melt pool properties are used to estimate the resulting solidification
microstructure. Microstructural predictions are compared to experimental metallography and
reasonably good agreement is achieved.","This work is sponsored by the Office of Naval Research
through grants N00014-11-1-0670 and N00014-14-1-0658.",,,,,
"['Subedi, Saroj', 'Ware, Henry Oliver Tenadooah']",2024-03-26T17:14:21Z,2024-03-26T17:14:21Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124381', 'https://doi.org/10.26153/tsw/50989']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['digital light processing', 'illumination', 'wavelength', 'additive manufacturing']",MODELING AND CORRECTING ILLUMINATION INHOMOGENEITY OVER MULTIPLE DLP ILLUMINATION INTENSITIES FOR BETTER FABRICATION ACCURACY,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e392d72-d9ec-4368-b34f-217a6a98569d/download,University of Texas at Austin,"Within custom Digital Light Processing (DLP) systems, various small issues either in the
optical assembly or with the DMD can lead to non-uniform illumination at the curing interface.
This inhomogeneity leads to inaccurate dimensions of fabricated features over the full print area.
To remedy this in our system, we have explored the relationship between LED output illumination,
divided the illuminated area into a regional mesh, measured the light intensity and grayscale values
over the mesh to obtain region-specific grayscale mask adjustments for illumination-leveling. This
process involves producing grayscale mask by quantifiably balancing the light intensity values
over build area and thus obtaining more uniform printed features. We compared the dimensional
accuracy of features printed using full white pixel value images for 250µm features and those
obtained using illumination-leveling grayscale processed images. Our results demonstrate the
effectiveness of our method to obtain dimensionally accurate features, thanks to the achieved
uniform illumination.",,,,,,
"['Jackson, Todd R.', 'Patrikalakis, Nicholas M.', 'Sachs, Emanuel M.', 'Cima, Michael J.']",2019-02-20T17:21:31Z,2019-02-20T17:21:31Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73455', 'http://dx.doi.org/10.26153/tsw/607']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LCC', '3D Printing']",Modeling and Designing Components with Locally Controlled Composition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5234484-6f7d-4741-859b-88909baa9bd0/download,,"SFF processes have demonstrated the ability to produce parts with locally controlled
composition. In the limit, processes such as 3D Printing,cancreate parts with composition
control on thelength scaleiof 100 microns.ToexploitthispC)tential,~e\\ZJnethodsto rnod~l,
exchange, and process parts.with local composition needtobe.deyeloped..... Anapproachtc)
modeling a part's geometty,.topology, and composition will be presented.· This.approachis
based on sUbdividing the solidmodel into sub-regions and associating analytic composition
blending functions \\lith each region. These blending functions definethe composition
throughout the model as mixtures ofthe primary materials available to·the SEF machine.
Various design tools will also be presented, for example, specification of com~ositionasa
function of the distance from the surface of a part. Finally,the role of design rules specifying
maximum concentrations and concentration.gradients will be discussed.",,,,,,
"['Li, W.', 'Zhang, J.W.', 'Karnati, S.', 'Zhang, Y.L.', 'Liou, F.', 'Newkirk, J.', 'Taminger, K.M.B.', 'Seufzer, W.L.']",2021-10-26T18:58:45Z,2021-10-26T18:58:45Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89556,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['functionally gradient material', 'pre-mixed multi-powder', 'FGM composition', 'numerical modeling']",Modeling and Experimental Investigation of Pre-Mixed Multi-Powder Flow in Fabricating Functional Gradient Material by Laser Metal Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8580f8a-ef50-4852-8495-1bd4e9fa4fe1/download,University of Texas at Austin,"Laser Metal Deposition (LMD) is an effective process to fabricate Functionally Gradient
Material (FGM) from pre-mixed powders. Since the supplied multi-powder directly affects the
deposited FGM’s composition, investigation on Pre-Mixed Multi-Powder (PMMP) flow during
LMD is greatly needed. This paper presents a comprehensive numerical PMMP flow model. By
solving discrete particle force balance equations coupled with continuity equations and
momentum equations for carrier gas, the dynamic behavior of PMMP flow through powder
feeder pipe and out of nozzle was calculated. To verify modeling results, pre-mixed Cu and 4047
Al powder was transported and patterned in an epoxy resin coating after exiting nozzle. The
distribution of exiting pre-mixed powder was plotted by quantifying the volume percentages of
different powders. The gathered distribution data was used to estimate the exiting pre-mixed
powder’s composition, and finally validate modeling results.",,,,,,
"['Bryant, Frances D.', 'Leu, Ming C.']",2021-09-23T21:52:31Z,2021-09-23T21:52:31Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88031', 'http://dx.doi.org/10.26153/tsw/14972']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Rapid Freeze Prototyping', 'support material', 'mechanical engineering']",Modeling and Experimental Results of Concentration with Support Material in Rapid Freeze Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7096937e-43f1-496d-909d-66d0d95d36df/download,,"Ice structures with complex geometries and overhung areas are created by the Rapid 
Freeze Prototyping (RFP) process in a sufficiently cool environment by freezing water into ice as 
the main material in conjunction with a eutectic dextrose-water solution as the sacrificial support 
material. The supported areas in an ice structure are removed via an increase in temperature in a 
separate environment after the structure is completely fabricated. To understand to what extent 
these two materials mix during fabrication, two methods of modeling the concentration changes 
that occur near the interface of the main and support materials have been developed. The 
simulation results based on these models along with some experimentally measured data are 
presented in this paper.",,,,,,
"['Anam, Md Ashabul', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-11T20:38:21Z,2021-10-11T20:38:21Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88636', 'http://dx.doi.org/10.26153/tsw/15570']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'Inconel 625', 'nickel-based superalloy', 'process parameters', 'dislocation density based crystal plasticity finite element model']",Modeling and Experimental Validation of Nickel-based Super Alloy (Inconel 625) Made Using Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/80e87820-175a-47ae-94a3-71d6d98e880a/download,University of Texas at Austin,"The formation of constituent phases in Selective Laser Melting of Inconel 625 is a function of
local temperatures, hold times at those temperatures, local cooling rates and local compositions
in the melt pool. These variables are directly correlated with input process parameters such as
beam power, scan speed, hatch spacing, beam diameter and thermo-mechanical characteristics of
the powder bed. The effect of these process parameters must be understood in order to properly
control the machines and predict the properties of parts being fabricated. To understand the
effects, IN625 coupons using eight different sets of processing parameters have been fabricated
and microstructure and mechanical properties were compared. These properties will be then used
to validate a dislocation density based crystal plasticity finite element model (DDCP-FEM).",,,,,,
"['Huang, Pu', 'Deng, Dongping', 'Chen, Yong']",2021-10-07T17:43:49Z,2021-10-07T17:43:49Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88492', 'http://dx.doi.org/10.26153/tsw/15426']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['heterogeneous object', 'material design', 'stereolithography', 'functional grading material', 'process planning']",Modeling and Fabrication of Heterogeneous Three-Dimensional Objects Based on Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8348412-bf5e-4f47-a693-f7d6e427b5fc/download,University of Texas at Austin,"Heterogeneous object modeling and fabrication has been studied in the past few decades. Recently the
idea of digital materials has been demonstrated by using Additive Manufacturing (AM) processes. Our
previous study illustrated that the mask-image-projection based Stereolithography (MIP-SL) process is
promising in fabricating such heterogeneous objects. In the paper, we present an integrated framework for
modeling and fabricating heterogeneous objects based on the MIP-SL process. Our approach can achieve
desired grading transmission between different materials in the object by considering the fabrication
constraints of the MIP-SL process. The MIP-SL process planning of a heterogeneous model and the
hardware setup for its fabrication are also presented. Test cases including physical experiments are
performed to demonstrate the possibility of using heterogeneous materials to achieve desired physical
properties. Future work on the design and fabrication of objects with heterogeneous materials is also
discussed.",,,,,,
"['Liou, Frank', 'Fan, Zhiqiang', 'Pan, Heng', 'Slattery, Kevin', 'Kinsella, Mary', 'Newkirk, Joseph', 'Chou, Hsin-Nan']",2020-03-09T14:42:52Z,2020-03-09T14:42:52Z,9/4/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80188', 'http://dx.doi.org/10.26153/tsw/7207']",eng,2007 International Solid Freeform Fabrication Symposium,Open,direct laser deposition,Modeling and Simulation of a Laser Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c63c2bd5-44f2-40f3-87f6-37bc95d697f7/download,,"A laser deposition process involves the supply of metallic powders into a laser-heated spot where
the powder is melted and forms a melt puddle which quickly solidifies into a bead. In order to
design an effective system, the laser beam, the powder beam, and their interactions need to be
fully understood. In this paper, the laser-material interaction within the melt pool is reported
using a multi-scale model: a macroscopic model to model mass, heat, and momentum transfer.
Experiments were also conducted to validate the simulation model.",,,,,,
"['Bryant, Frances D.', 'Leu, Ming C.']",2020-03-09T14:53:10Z,2020-03-09T14:53:10Z,9/4/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80190', 'http://dx.doi.org/10.26153/tsw/7209']",eng,2007 International Solid Freeform Fabrication Symposium,Open,"['Rapid Freeze Prototyping', 'solid freeform fabrication process']",Modeling and Validation of Temperature and Concentration for Rapid Freeze Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7abe8d9e-ad94-418a-aeee-d9a6e46229e8/download,,"Rapid Freeze Prototyping is a solid freeform fabrication process that uses water as the main build
material in a cold environment to create three-dimensional parts. A eutectic sugar-water solution
(C6H12O6 – H2O) has been used as a sacrificial material in order to create complex 3D parts with
features such as overhangs. A study of the interaction of the build and support materials is
presented in this paper. The temperature of both materials during deposition and subsequent
cooling is modeled using a semi-empirical model and a theoretical model. A concentration
model is used to predict the concentration in the fabricated parts around the interface of the two
materials with predicted temperatures as input. Experiments are conducted to validate both the
temperature and concentration models.",,,,,,
"['Dwivedi, Rajeev', 'Zekovic, Srdja', 'Kovacevic, Radovan']",2020-03-02T15:42:12Z,2020-03-02T15:42:12Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80137', 'http://dx.doi.org/10.26153/tsw/7158']",eng,2006 International Solid Freeform Fabrication Symposium,Open,SolidFreeform-Fabrication,Modeling and Verification of Error Propagation in Integrated Additive/Subtractive Multi-Directional Direct Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/014eb756-d0af-4bd9-a0ea-ecebf26c3a44/download,,"Integrated additive-subtractive manufacturing, when applied in the framework of SolidFreeform-Fabrication (SFF) allows the fabrication of functional parts on single platform, directly from its computer model. Reduction in process complexity and total processing steps is
ensured by multi-directional material deposition and machining. However, due to shift in the
datum location in reorientation steps and sequential addition of material in the form of layers,
the CAD process intent is not exactly replicated. This leads to inclusion of dimensional errors.
Machining in order to eliminate the errors as frequent as layer deposition is highly expensive
and can be avoided by estimation of errors and varying process parameters, and/or performing
machining after a set of layers are deposited. This paper proposes a state space model for modeling the error propagation due to linear as well as angular variation in the datum. The model
is based on identification of possible sources of error, mechanism of error inclusion and influence
of process parameters. An experiment performed to determine parameters of error modeling
has been reported.",,,,,,
"['Pierce, Jason B.', 'Smith, Douglas E.']",2024-03-26T17:16:28Z,2024-03-26T17:16:28Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124382', 'https://doi.org/10.26153/tsw/50990']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['computational fluid dynamics', 'discrete element modeling', 'carbon fiber', 'suspension dynamics', 'additive manufacturing']",MODELING CARBON FIBER SUSPENSION DYNAMICS FOR ADDITIVE MANUFACTURING POLYMER MELT FLOWS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9fe49a38-cd58-4d1b-b5cb-fb2edc2209e9/download,University of Texas at Austin,"The addition of short carbon fibers to the feedstock of large-scale polymer
extrusion/deposition additive manufacturing results in significant increases in mechanical
properties dependent on the fiber distribution and orientation in the beads. In order to analyze those
factors, a coupled computational fluid dynamics (CFD) and discrete element modeling (DEM)
approach is developed to simulate the behavior of fibers in an extrusion/deposition nozzle flow
after calibrations in simple shear flows. The DEM model uses bonded discrete particles to make
up flexible and breakable fibers that are first calibrated to match Jeffery’s orbit and to produce
interactions that are consistent with Advani-Tucker orientation tensor predictions. The DEM/CFD
model is then used to simulate the processing of fiber suspensions in the variable flow and
geometries present in extrusion/deposition nozzles. The computed results provide enhanced
insight into the evolution of fiber orientation and distribution during extrusion/deposition as
compared to existing models through individual fiber tracking over time and space on multiple
parameters of interest such as orientation, flexure, and contact forces.",,,,,,
"['Jariwala, Amit S.', 'Ding, Fei', 'Boddapati, Aparna', 'Breedveld, Victor', 'Grover, Martha', 'Henderson, Clifford L.', 'Rosen, David W.']",2021-09-30T18:43:27Z,2021-09-30T18:43:27Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88275', 'http://dx.doi.org/10.26153/tsw/15216']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'additive manufacturing', '2D photopolymerization model', 'oxygen inhibition', 'oxygen diffusion']",Modeling Effects of Oxygen Inhibition in Mask Based Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/33e36670-4d7a-4512-b786-6ddf97505cf2/download,University of Texas at Austin,"Stereolithography (SL) is an additive manufacturing process in which liquid
photopolymer resin is cross-linked and converted to solid with a UV laser light source.
Traditional models of SL processes do not consider the complex chemical reactions and species
transport occurring during photopolymerization and, hence, are incapable of accurately
predicting resin curing behavior. In this paper, a 2D photopolymerization model based on
ordinary differential equations is presented that incorporates the effects of oxygen inhibition and
diffusion during the polymerization process. This model accurately predicts the cured part height
when compared to experiments conducted on a mask based stereolithgraphy system. The
simulated results also show the characteristic edge curvature as seen in experiments. Parametric
studies were conducted to investigate the possibilities to improve the accuracy of the model for
predicting the edge curvature.",,,,,,
"['Boddu, Mallikharjuna R.', 'Thayalan, Vishnu P.', 'Landers, Robert G.']",2019-11-20T16:10:48Z,2019-11-20T16:10:48Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78467', 'http://dx.doi.org/10.26153/tsw/5552']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Aided Manufacturing,Modeling for the Control of the Laser Aided Manufacturing Process(LAMP),Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f60edb1-7bfd-4c03-9c56-f46aad902bf3/download,,"Many state–of–the–art Rapid Prototyping (RP) technologies adopt lasers to fabricate 3–D solid
parts by material deposition in layers. The ability of these RP technologies to control the process
requires a thorough understanding of the process mechanics. This paper presents the analysis of
an analytical, dynamic model explaining the complex phenomenon of Laser Aided
Manufacturing Process (LAMP). The equilibrium of the dynamic model is analyzed and
dynamic simulations are performed to determine its stability characteristics. This model forms
the basis for the real–time control of the LAMP.","The authors gratefully acknowledge the financial support of the National Science Foundation
(DMI–9871185), Society of Manufacturing Engineers (#02022–A), Missouri Research Board,
and UMR’s Intelligent Systems Center.",,,,,
"['Wu, Yan', 'Yang, Li']",2021-11-04T19:21:43Z,2021-11-04T19:21:43Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90008', 'http://dx.doi.org/10.26153/16929']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['2D lattice structures', 'unit cell', 'deformation', 'fracture behavior', 'crack propagation', 'additive manufacturing']",Modeling of Crack Propagation in 2D Brittle Finite Lattice Structures Assisted by Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2600499f-969f-40ea-8411-50a8d24a9079/download,University of Texas at Austin,"The failure characteristics of lattice structures are of significant importance in various
lightweight applications such as aerospace and biomedicine. In this study, several 2D lattice
structures with different number of unit cells that represent different geometrical characteristics
and deformation mechanisms were investigated for their fracture behaviors. The fracture
characteristic of the cellular samples was studied experimentally through tensile testing. The
fracture propagation patterns of different lattice designs were investigated by high-speed
camera, and consequently analyzed via analytical model in order to evaluate the effect of finite
unit cells on the fracture characteristics of these cellular structures. The results were further
compared with the classic cellular fracture theory by Gibson and Ashby. The comparison results
suggest that for small number of unit cells designs the homogenized fracture model does not
provide accurate crack propagation predictions.",,,,,,
"['Turner, Irem Y.', 'Wood, Kristin L.', 'Busch-Vishniac, Ilene J.']",2018-11-08T15:03:25Z,2018-11-08T15:03:25Z,1995,Mechanical Engineering,doi:10.15781/T2RB6WN2V,http://hdl.handle.net/2152/69881,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'Modeling and Simulation', 'iron-galvanometer']",Modeling of Dynamic Effects Caused by the Beam Delivery System in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c55470b8-799f-4ff3-9568-4ef56523a11f/download,,"In this work, the machine dynamic response in Selective Laser Sintering is investigated with
the purpose of determining the causes of scanning errors. Machine subcomponents are first
investigated to determine their potential effects on the laser beam positional accuracy. The
dynamics of the laser beam delivery system are identified as the major contributor to deviations
in the laser beam position. The moving-iron galvanometer scanner used in SLS machines is then
modeled, with the ultimate goal of understanding how its various components and parameters
affect part scanning accuracy. This work should provide a better understanding of the dynamics
of the laser beam delivery system and give insight on machine parameters that result in better
part accuracy.",,,,,,
"['Kim, Dong Sung', 'Suriboot, Jakkrit', 'Grunlan, Melissa', 'Tai, Bruce L.']",2021-11-04T15:01:10Z,2021-11-04T15:01:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89979,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'silicone 3D printing', 'low one-photon polymerization']",Modeling of Low One-Photon Polymerization for 3D Printing of UV-Curable Silicones,Conference paper,https://repositories.lib.utexas.edu//bitstreams/293a0e67-a471-487e-8347-ecb221100021/download,University of Texas at Austin,"Low-one photon polymerization (LOPP) enables an in-liquid curing to suspend a soft
silicone object in the vat without mechanical disturbance. LOPP requires a low-absorbance
wavelength and a great gradient light beam to achieve the desired curing. To further control the
process for 3D printing, this research aims to model LOPP behaviors of a custom-made UV-curable silicone system based on Gaussian beam and Beer-Lambert law. A methyl acrylate-based
silicone was specifically formulated to pair with a 375 nm UV light and high numerical aperture
lens in this work. The silicone was established with critical exposure and penetration depth by a
modified “windowpane” test. The comparison results between the model and LOPP tests showed
a consistent trend of polymerization. This model suggested a large penetration depth and smaller
critical exposure to achieve an ideal LOPP-based printing.",,,,,,
"['Wu, Zhanping', 'Ogale, Amod A.', 'Ahzi, Said', 'Paul, Frank W.', 'Hunt, Elaine']",2018-12-07T17:15:46Z,2018-12-07T17:15:46Z,1997,Mechanical Engineering,doi:10.15781/T23776F87,http://hdl.handle.net/2152/71453,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['rapid prototypes', 'manufacturing']",Modeling of Mechanical Behavior of SLA Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/90553b9f-a9bf-4105-8bc9-f67fcdfc0ecb/download,,"In recent years, important efforts have been focused on producing functional parts using
Stereolithography Apparatus ( SLA ). One of the applications is the development of rapid
polymer tooling such as dies for injection molding. For these applications, optimal thermal as
well as mechanical properties are of significance. In this paper, the mechanical behavior of the
cured resin SL5170 is discussed by use of an elastic-viscoplastic material model. Uniaxial
compression tests at different deformation rates are conducted. The stress-strain curves of these
tests are predicted by the model, and comparisons of these results with experiments show good
agreement.",,,,,,
"['Vail, N.K.', 'Barlow, J.W.']",2018-10-03T18:35:54Z,2018-10-03T18:35:54Z,1994,Mechanical Engineering,doi:10.15781/T2930PD6F,http://hdl.handle.net/2152/68675,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'green composites', 'polymer binder materials']",Modeling of Polymer Degradation in SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7df24bd2-6331-4d61-a601-06c18f1ed63e/download,,"A simple computer model has been developed to predict the thermal
degradation of polymer binders used in the fabrication of composite
green shapes from high temperature ceramic materials.
Decomposition rate kinetics of the polymer materials were
determined and incorporated into the model. The polymer
degradation occurring in three separate powder systems was
determined as a function of applied laser energy. Agreement
between model results and experimental data is quite good.
(Key Words: Polymer, Degradation, Selective Laser Sintering,
Composites).",,,,,,
"['Flood, Aaron', 'Liou, Frank']",2021-10-21T16:59:26Z,2021-10-21T16:59:26Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89406,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['powder bed processing', 'powder bed', 'Discrete Element Method', 'Geometric Method']",Modeling of Powder Bed Processing – A Review,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38c35c84-2e49-4d2f-9e99-d9179de341a8/download,University of Texas at Austin,"Many models have been developed to model powder beds and these methods can be
implemented to model a powder bed for Selective Laser Sintering, Selective Laser Melting and
any other technique of additive manufacturing which uses powder beds. Two of the main
systems are the Discrete Element Method (DEM) and the Geometric Method. The purpose of
this paper is to analyze each of the methods. It will first highlight how each of the models creates
the powder bed. The next aspect reviewed is the computational time and its causes. And lastly,
each of the methods will be examined for their accuracy as shown from various experiments that
have been reported in literature. In addition to these methods, there are several others that have
been proposed that will also be studied and compared to highlight the strengths and weaknesses
of each.",,,,,,
"['Mendez, Patricio', 'Brown, Stuart']",2018-10-03T16:03:32Z,2018-10-03T16:03:32Z,1994,Mechanical Engineering,doi:10.15781/T2GQ6RM7G,http://hdl.handle.net/2152/68658,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'model', 'thermal']",Modeling of Selected SFF Process Limits,Conference paper,https://repositories.lib.utexas.edu//bitstreams/74717653-2585-4b16-8ba9-5a3d5d75242c/download,,"An analytical model of the thermal field for one scan line during SLS is developed. Quantitative relationships
between net heat input and beam velocity are stated for sintering at a given distance from the center
of the beam and for the case of maximum surface temperature. For the maximum surface temperature, two
extreme cases have been analyzed: pure conduction heat transport, and highly convective molten consolidation.
It is suggested that a highly convective process allows significantly higher net heat input than pure
conduction. It is found that for certain conditions, the relationship between net heat input and beam velocity
is independent of the thermal conductivity of the material. Key Words: model, melting, selective laser
sintering, thermal, process window.",,,,,,
"['Jacquot, Y.', 'Zong, S.', 'Marcus, H.L.']",2018-04-10T17:25:23Z,2018-04-10T17:25:23Z,1990,Mechanical Engineering,doi:10.15781/T2ZS2KW7H,http://hdl.handle.net/2152/64240,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SFF', 'SALD', 'selective area laser deposition']",Modeling of Selective Area Laser Deposition for Solid Freeform fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a8abd8cf-12f7-4376-b2cd-597af851c2ed/download,,"The results of a theoretical study of the selective area laser deposition process used for Solid
Freeform Fabrication (SFF) from gas phase is presented. We show how the deposition profile of
carbon deposited via pyrolytic laser chemical vapor deposition using acetylene as the source gas
can be computed by taking into account heat transfer, reaction, and mass transfer processes inside
the reactor. The two dimensional representation of the related experimental variables are used to
describe the substrate temperature, carbon deposit, and acetylene concentration in the process. The
parameters describing these processes are estimated.",,,,,,
"['Dai, K.', 'Crocker, J.', 'Shaw, L.', 'Marcus, H.']",2019-10-18T15:42:26Z,2019-10-18T15:42:26Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76243', 'http://dx.doi.org/10.26153/tsw/3332']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Deposition,Modeling of Selective Area Laser Deposition Vapor Infiltration (SALDVI) of Silicon Carbide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67e87486-9a13-40ac-a04a-bb476f6dae4b/download,,"Selective Area Laser Deposition Vapor Infiltration (SALDVI) is a developing
solid freeform fabrication (SFF) technique in which porous layers of powder are
densified by infiltrating the pore spaces with solid material deposited from a gas
precursor during laser heating. A 3D finite element model was developed that simulates
SALDVI of silicon carbide. The model predicts the laser input power and the distribution
of vapor deposited SiC within the powder bed as well as on the surface of the powder bed
(SALD). The model considers a moving Gaussian distribution laser beam, temperatureand porous-dependent thermal conductivity, specific heat and temperature-dependent
deposition rate. Furthermore, the model also includes closed-loop control of the laser
power to achieve a desired target processing temperature on the top surface of the power
bed. The simulation results agree fairly well with experimental data for simple
geometries and offer guidelines for further experimental studies of the SALDVI process.",,,,,,
"['Pan, Heng', 'Liou, Frank']",2020-02-14T16:23:16Z,2020-02-14T16:23:16Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79993', 'http://dx.doi.org/10.26153/tsw/7018']",eng,2004 International Solid Freeform Fabrication Symposium,Open,direct laser deposition process,Modeling of the Metal Powder Flow with Carrier Gas in Coaxial Nozzle for Direct Laser Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4ed514ee-746b-4cb6-add4-3f7cee8da850/download,,"In direct laser deposition process, metal powder is directly fed with carrier gas
through the coaxial nozzle into the melt pool created by the laser to form the solid parts.
Many operational parameters of the process depend on the characteristic of the powder
stream structure below the exit of the coaxial nozzle. In this paper, a computational
approach is developed for the simulation of the gas-particle flow in the coaxial nozzle.
By taking into account the nozzle geometry and operating parameters, such as width and
inclination angle of powder passage and carrier gas velocity, the developed
computational code allows the simulation, optimization and control of the delivery of the
metal powders.",,,,,,
"['Bai, X.W.', 'Zhang, H.O.', 'Wang, G.I.']",2021-10-18T21:29:29Z,2021-10-18T21:29:29Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89252,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['induction heating', 'weld-based additive manufacturing', 'residual stresses']",Modeling on the Moving Induction Heating Used in Weld-Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e93b56a8-0811-4269-be4b-252a69ed6cc1/download,University of Texas at Austin,"This paper numerically investigates the application induction heating in weld-based additive
manufacturing to reduce residual stresses. To avoid time-consuming transient electromagnetic calculation, the
induction heat is assumed to be constant in the arc coordinate. Thermo-electromagnetic coupling analysis is
performed only at a typical time to obtain the representative distribution of induction heat, which is then
transferred to the thermal analysis of multilayer deposition as a secondary heat source. Furthermore, the effects
of real-time induction preheating and postheating on residual stress state are analyzed in comparative
simulations. The results show that both induction preheating and postheating lead to more homogeneous heat
input and lower residual stresses compared with the case without induction heating.",,,,,,
"['Thomas, J. P.', 'Rodriguez, J. F.']",2019-06-13T14:07:44Z,2019-06-13T14:07:44Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/74942', 'http://dx.doi.org/10.26153/tsw/2054']",eng,2000 International Solid Freeform Fabrication Symposium,Open,"['Fused-Deposition (FD)', 'FD-ABS']",Modeling the Fracture Strength between Fused-Deposition Extruded Roads 16,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc3e3f26-0cf5-4fc6-8919-29b0f1d455a1/download,,"The fracture strength developed between Fused-Deposition extruded roads is modeled in
terms of the wetting and thermally-driven diffusion bonding processes. Thermal histories at the
road-to-road interface are obtained from a heat transfer analysis and used to develop model
predictions based on reptation theory for the interdiffusion of long-chain polymer molecules.
Fracture toughness data on FD-ABS plastic specimens is used to quantify the model. The results
show that most of the fracture strength develops during the surface wetting stage of bonding and
that slower cooling rates during solidification promote stronger bonding between the roads.",,,,,,
"Soylemez, E.",2021-11-11T16:41:00Z,2021-11-11T16:41:00Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90242', 'http://dx.doi.org/10.26153/tsw/17163']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['finite element analysis', 'selective laser melting', 'keyhole', 'process map']",Modeling the Melt Pool of the Laser Sintered Ti6Al4V Layers with Goldak's Double-Ellipsoidal Heat Source,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4eb85183-6308-41b1-a77a-a7d09e6c1487/download,University of Texas at Austin,"Selective laser melting process has been widely studied to elucidate the effects of process
parameters (laser speed, laser power, scan strategy, hatch distance, layer thickness, etc.) on
the manufactured parts. Experimental and numerical modeling studies have been investigating
the melt pool shapes of the laser sintered layers to correlate the melt pool geometry with the part
quality. Although modeling results agree with the experiments, the melt pool cross-section may
form key holing rather than semi-circular shape due to Marangoni effect, recoil pressure, and
sudden evaporation for some process parameters combinations. To accurately model the melt
pool depth, this study proposes a finite element analysis (FEA) model that simulates the laser
source as the Goldak’s double-ellipsoidal heat power density model. Single bead experiments of
Ti6Al4V were conducted within the processing range of laser sintering system with the 400 W
laser, and these experimental results allowed to verify simulated FEA results.",,,,,,
"['Hoskins, Dylan', 'Kim, Seokpum', 'Hassen, Ahmed', 'Lindahl, John', 'Kunc, Vlastimil', 'Duty, Chad']",2021-11-18T17:02:23Z,2021-11-18T17:02:23Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90429', 'http://dx.doi.org/10.26153/tsw/17350']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['coefficient of thermal expansion', 'CTE', 'non-homogenized approach', 'large area extrusion deposition additive manufacturing', 'LAEDAM']",Modeling Thermal Expansion of a Large Area Extrusion Deposition Additively Manufactured Parts Using a Non-Homogenized Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7518b6b0-45f7-486b-806c-0c86871b255b/download,University of Texas at Austin,"Interest in the use of large area extrusion deposition additive manufacturing (LAEDAM) to
create tools for creation of composites is on the rise, due to its ability to create complex shapes
rapidly. To ensure the parts created from the tool meet geometric standards, it is important to
understand the thermal expansion of the printed part. Which is a challenge as LAEDAM imparts
a non-uniform fiber orientation to the deposited material. A non-uniform fiber orientation in the
deposited material creates a non-homogeneous cross section at a given position. Due to this
heterogeneity, the coefficient of thermal expansion (CTE) also varies according to the position in
the cross section. Previous modelling attempts of LAEDAM parts have employed a
homogenized approach. This work experimentally characterizes CTE variations across the cross
section of a bead using thermomechanical analysis and uses this as a non-homogenized input at
the bead level for a finite element model. Predictions from this finite element model are then be
compared to strain maps measured using 2-D digital image correlation of large-scale printed
parts (127 mm cubes).",,,,,,
"['Li, Mingyang', 'Landers, Robert G.', 'Leu, Ming C.']",2021-10-06T21:21:53Z,2021-10-06T21:21:53Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88448', 'http://dx.doi.org/10.26153/tsw/15385']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['ceramic paste solidifcation', 'numerical simulations']","Modeling, Analysis and Simulation of Paste Freezing in Freeze-form Extrusion Fabrication",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9fad069-d680-4248-b2de-7eaa0a05c1cf/download,University of Texas at Austin,"During the freeze-form extrusion fabrication process for aqueous-based pastes, the sub-zero
temperature environment aids the part in maintaining its shape by freezing the water present in
the paste. The paste freezes very quickly when deposited on a substrate in a freezing
environment. However, as the part’s height increases, the freezing time increases as the heat
conduction rate to the substrate decreases. The freezing time can exceed the time required to
extrude one layer of paste due to water’s high latent heat, thus leaving the extruded paste in its
semi-liquid state and causing the part to deform or even collapse. Therefore, dwell time is
needed between layers, which may substantially increase the build time of the part. In this paper,
the effects of the paste material, paste solids loading, convection coefficient, initial paste
temperature, ambient temperature, total time between layers, and layer thickness on the freezing
time of paste are investigated. The paste temperature and paste freezing time are computed for
various process parameters via numerical simulation using the commercial code Fluent.",,,,,,
"['Šeta, Berin', 'Mollah, Md. Tusher', 'Kumar, Vipin', 'Pokkalla, Deepak Kumar', 'Kim, Seokpum', 'Hassen, Ahmed Arabi', 'Spangenberg, Jon']",2023-01-26T21:37:50Z,2023-01-26T21:37:50Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117324', 'http://dx.doi.org/10.26153/tsw/44205']",eng,2022 International Solid Freeform Fabrication Symposium,Open,molding,Modelling Fiber Orientation during Additive Manufacturing-Compression Molding Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44604e13-e0f8-45ff-be64-edc945b3f225/download,,"The production of high-performance thermoplastic composites reinforced with short carbon fibers can be 
achieved by a novel “additive manufacturing-compression molding” technique. An advantage of such a 
combination is two-fold: controlled fiber orientation in additive manufacturing and less void content by 
compression molding. In this study, a computational fluid dynamics model has been developed to predict the 
behavior of printed layers during fiber-reinforced thermoplastic extrusion and subsequent compression molding. 
The fiber orientation was modelled with the simple quadratic closure model. The interaction between the fibers 
was included using a rotary diffusion coefficient that becomes significant in concentrated regimes. Finally, the 
second rank orientation tensor was coupled with the momentum equation as an anisotropic part of the stress term. 
The effect of different fiber orientation within printed layers was investigated to determine the favorable printing 
scenarios in the strands that undergo compression molding afterwards. The developed numerical model enables 
design of high-performance composites with tunable mechanical properties.",,,,,,
"['Wu, Yan', 'Yang, Li']",2021-11-30T21:57:40Z,2021-11-30T21:57:40Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90563', 'http://dx.doi.org/10.26153/tsw/17482']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['tensile fracture', 'cellular structures', 'crack propagation', 'size effect']",Modelling for the Tensile Fracture Characteristic of Cellular Structures under Tensile Load with Size Effect,Conference paper,https://repositories.lib.utexas.edu//bitstreams/60c3a425-180a-46c5-bb3c-10d43c019146/download,University of Texas at Austin,"In the unit cell-based design of cellular structures, an important issue is the effect of the
cellular pattern size (i.e. the number of unit cell numbers along different orientations) on their
mechanical properties. Among these properties, the fracture properties are of great importance
for a broad range of applications but have been rarely investigated. In this work the size effects
on the fracture characteristic (including failure initiation, crack propagation and failure patterns)
of the BCC, octet-truss, auxetic and octahedral structures under tensile loadings were analyzed
based analytical models. It was found that for the fracture of the cellular structures there exist
significant coupling effects between the unit cell topology and the cellular pattern size. The
results also clearly suggested the importance of dedicating more design attentions to the
boundaries of the cellular structures during their fracture designs. This study provides additional
insights into the design considerations for the fracture properties of the cellular structures.",,,,,,
"['Dibua, Obehi G.', 'Yuksel, Anil', 'Roy, Nilabh K.', 'Foong, Chee S.', 'Cullinan, Michael']",2021-11-03T20:33:23Z,2021-11-03T20:33:23Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89925,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['nanoparticle diffusion', 'nanoparticle sintering', 'modelling', 'microscale selective laser sintering', 'μ-SLS']",Modelling Nanoparticle Sintering in a Microscale Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a530b4b-0f73-4289-afb8-2e540948faf4/download,University of Texas at Austin,"An important aspect of making microscale selective laser sintering (μ-SLS) a viable
commercial process is having the ability to predict the structural properties of sintered parts. This
prediction is made possible through accurate models of the sintering process. The majority of SLS
models simulate sintering as a melting process which is accurate for microparticles. However, for
nanoscale particles the sintering process becomes dominated by grain boundary and surface
diffusion between particles. Though there are currently research efforts on modeling the sintering
behavior between nanoparticles, these efforts revolve around simulations with only a few
particles. This paper presents an approach to modelling diffusion between nanoparticles in full
sized beds made up of hundreds of particles. The simulations presented in this paper are done
using a phase field modeling (PFM) approach that can be used to predict properties such as the
porosity, shrinkage and relative density of sintered parts, which can then be compared against
experimental data.",,,,,,
"['Lee, Yousub', 'Simunovic, Srdjan', 'Gibson, Brian', 'Mhatre, Paritosh', 'Roschli, Alex']",2023-01-26T15:12:33Z,2023-01-26T15:12:33Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117315', 'http://dx.doi.org/10.26153/tsw/44196']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Ti-6Al-4V,Modelling of Microstructure Evolution in Wire-Based Laser Direct Energy Deposition with Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8c6b7d5-6e88-4b51-aa6c-3cbd7b75cbcb/download,,"Over the past years, wire-based direct energy deposition (DED) has been transitioning from rapid 
prototyping to the production of end-use part and mass production. However, a wide market 
penetration of the DED has not happened yet. The difficulties for wide-scale market adoption to 
critical structural components are related to the development cost for process optimization and for 
manufacturing of high-quality parts. For metallic components, the process conditions (e.g., power, 
speed, tool path) control the material and mechanical properties/performance of the printed part. The 
thermal history strongly determines the phase fraction, morphology, growth pattern, size of 
microstructure, and nature of defects. Thus, in this study, we: 1) developed a thermal simulation using 
finite element method, 2) experimentally measured thermal histories from a U-shaped part with four 
tool paths of horizontal, vertical, raster, and contour to calibrate and validate the thermal model, and 3) 
investigated the effect of thermal history on microstructure evolution and quantified the 
microstructural variation during the printing process.",,,,,,
"['Ryder, G. J.', 'Berzins, M.', 'Childs, T. H. C']",2018-11-16T16:03:58Z,2018-11-16T16:03:58Z,1996,Mechanical Engineering,doi:10.15781/T2JQ0TF3G,http://hdl.handle.net/2152/70292,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['sintering process', 'sintering machines', 'Selective Laser Sintering process']",Modelling Simple Feature Creation in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee6fca47-27eb-4ee6-89e1-8da06158fe77/download,,"A two dimensional finite difference thermal sintering model has been created to describe
the Selective Laser Sintering process(SLS). It includes thermal property variation with position
and temperature, and especially adaptive meshing to refine information in regions of high
temperature gradients. It has been used to predict density and temperature in both single and
multi layer sintering operations, corresponding to experimental results. This paper will present
comparisons of theory and experiment for the SLS of simple geometries such as blocks, steps,
and cylinders.",,,,,,
"['Xue, Samuel S.', 'Barlow, Joel W.']",2018-04-12T18:31:32Z,2018-04-12T18:31:32Z,1991,Mechanical Engineering,doi:10.15781/T22F7K78V,http://hdl.handle.net/2152/64283,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Chemical Engineering Department', 'SLS', 'Maxwell-Eucken Model', 'models']",Models for the Prediction of the Thermal,Conference paper,https://repositories.lib.utexas.edu//bitstreams/234ebc93-cb17-427e-84c8-c58eb8b65529/download,,"Five models and eq\1ationsJorthe.predictic;>nof the tbertnal conduc~""ities of powders in the
literature are compared with the data obtainedill the experiments of the authors. Anew modified
ntodel for the. correlation of the experimental data is presented.
Key words: differential scanning calorimetry, porosity, solid content, specific heat, thermal
conductivity.",,,,,,
"['Liang, Xuan', 'Chen, Qian', 'Cheng, Lin', 'Yang, Qingcheng', 'To, Albert']",2021-11-08T21:52:23Z,2021-11-08T21:52:23Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90051', 'http://dx.doi.org/10.26153/tsw/16972']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'inherent strain', 'modified method', 'residual distortion']",A Modified Inherent Strain Method for Fast Prediction of Residual Deformation in Additive Manufacturing of Metal Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c48dff75-ea2f-4cb9-991f-33da1a06fa68/download,University of Texas at Austin,"Effective prediction of residual deformation is very important to guarantee the quality of
metal parts produced by additive manufacturing (AM). However, analytical or numerical models
for the AM process are complicated and time consuming thus far. The conventional inherent
strain theory can predict residual distortion of the regular metal welding problem. Typically, it is
not applicable to the complicated layer-by-layer laser-sintering depositing process. In this paper,
a modified inherent strain method is presented to predict the residual deformation much more
efficiently. Calculation of the modified inherent strain is based on small-scale thermomechanical
simulation of the AM process. Next, the strain values are assigned to the heat-affected zone as
material thermal property and a one-time static mechanical analysis is performed. Residual
deformation obtained by the new method and the thermomechanical simulation indicates good
accuracy and efficiency of the proposed method.",,,,,,
"['Hagen, Deborah', 'Chen, Alex', 'Beaman, Joseph J.', 'Kovar, Desiderio']",2021-11-18T01:55:56Z,2021-11-18T01:55:56Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90403', 'http://dx.doi.org/10.26153/tsw/17324']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser flash sintering', 'moisture', 'yttria-stabilized zirconia', 'ceramics']",Moisture Effects on Selective Laser Flash Sintering of Yttria-Stabilized Zirconia,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b13fce3a-801f-477a-bb1a-f7b9738b5b48/download,University of Texas at Austin,"Selective laser flash sintering (SLFS) combines a uniform electric field with a localized,
scanning laser as the only external heating source. The presence of a large uniform electric field
can greatly increase the sintering rate and lower the sintering temperature for ceramics. The
combination of lower sintering temperature and faster sintering rates may allow SLFS to be used
for ceramic additive manufacturing. In this work, we study the effects of moisture on SLFS of
yttria-stabilized zirconia ceramic. We compare the effects of processing parameters on the
initiation of SLFS for samples exposed to a range of moisture levels.",,,,,,
"['Sinico, M.', 'Ranjan, R.', 'Moshiri, M.', 'Ayas, C.', 'Langelaar, M.', 'Witvrouw, A.', 'van Keulen, F.', 'Dewulf, W.']",2021-11-30T19:54:36Z,2021-11-30T19:54:36Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90528', 'http://dx.doi.org/10.26153/tsw/17447']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'laser powder bed fusion', 'mold insert']",A Mold Insert Case Study on Topology Optimized Design for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa3d7107-5752-40db-952d-35b61533d1b9/download,University of Texas at Austin,"The Additive Manufacturing (AM) of injection molding inserts has gained popularity during recent years
primarily due to the reduced design-to-production time and form freedom offered by AM. In this paper, Topology
Optimization (TO) is performed on a metallic mold insert which is to be produced by the Laser Powder Bed
Fusion (LPBF) technique. First, a commercially available TO software is used, to minimize the mass of the
component while ensuring adequate mechanical response under a prescribed loading condition. The commercial
TO tool adopts geometry-based AM constraints and achieves a mass reduction of ~50 %. Furthermore, an
in-house TO method has been developed which integrates a simplified AM process model within the standard
TO algorithm for addressing the issue of local overheating during manufacturing. The two topology optimized
designs are briefly compared, and the advantages of implementing manufacturing constraints into the TO
algorithm are discussed.",,,,,,
"['Zhirnov, I.', 'Doubenskaia, M.', 'Kotoban, D.']",2021-11-03T22:13:23Z,2021-11-03T22:13:23Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89949,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['thermographic monitoring', 'single-track degradation', 'single-track', 'selective laser melting']",Monitoring of Single-Track Degradation in the Process of Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d0118d3-b0c7-403b-8e5d-da7c4f586710/download,University of Texas at Austin,"Selective laser melting machines provide the optimal working parameters for
manufacturing during the process. However, the laser interaction with metal powder is an
unstable. The gasdynamic flows make powder particles move and escape from the melt pool.
This phenomenon leads to an irregular distribution of the material volume being remelted. Since
the energy is constant during the process, single-tracks with different geometry are appeared and
their superposition forms the 3D-object. To detect the process abnormality of stable track
formation there was developed a control system based on morphological analysis of thermal
image obtained by IR-camera. The temperature field distribution along the image matrix’s row
with the maximum temperature was used as influencing factor on stable track formation.
Roughness was reduced from 39.9 to 6.6 µm by using control system with the same process
parameters. The obtained results can be applied in industrial SLM machines with the integrated
active control system.",,,,,,
"['Ziemian, C.W.', 'Cipoletti, D.E.', 'Ziemian, S.N.', 'Okwara, M.N.', 'Haile, K.V.']",2021-10-13T19:36:18Z,2021-10-13T19:36:18Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88770', 'http://dx.doi.org/10.26153/tsw/15704']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'monotonic tensile fatigue', 'cyclic tensile fatigue', 'tensile behavior', 'ABS components']",Monotonic and Cyclic Tensile Properties of ABS Components Fabricated by Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9107bcbf-ec33-4246-ac3d-ed0aaf4b2ce0/download,,"An investigation of tensile strength and cyclic tension-tension fatigue behavior has been
performed on layered ABS components fabricated by fused deposition modeling (FDM).
Experimentation was designed to focus specifically on the effect of specimen mesostructure on
monotonic tensile behavior and tensile-fatigue life. Analyzed mesostructures include
unidirectional laminae with parallel fiber orientations ranging from θ = 0° (aligned with the
loading axis) to θ = 90° (perpendicular to the loading axis), and alternating laminae with a
layering pattern of θ°/(θ-90°) fiber orientations. The unidirectional 0° specimens achieved the
greatest tensile strength and effective elastic modulus, while the alternating +45°/-45° specimens
displayed the best fatigue performance of the specimens tested. Results highlight the anisotropic
behavior of FDM components and suggest that the tensile behavior is improved by aligning the
fibers of unidirectional laminae more closely with the axis of the applied stress. In addition, the
specimens with θ°/(θ-90°) fiber orientations displayed incrementally improved tensile properties
and fatigue performance from an apparent offsetting effect that results from alternating laminae.
The fracture surfaces of the specimens were analyzed using scanning electron microscopy in
order to gain further insights into the fatigue damage and failure mechanisms.",,,,,,
"['Xian, Y.', 'Rosen, D.W.']",2021-11-09T19:52:01Z,2021-11-09T19:52:01Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90146', 'http://dx.doi.org/10.26153/tsw/17067']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['moving morphable components', 'MMC', 'topology optimization', 'support structures', 'material anisotropy', 'additive manufacturing']",Morphable Components Topology Optimization for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3342766-8fd1-4b2e-ab3c-70d297035c3a/download,University of Texas at Austin,"This paper addresses two issues: 1. Topology optimization (TO) yields designs that may
require support structures if additively manufactured, which increase material and clean-up costs.
2. Material anisotropy is induced during additive manufacturing, which results in inaccurate TO
results if such material properties are not included in the algorithm. This paper, based on a
moving morphable components (MMC) approach where structure is composed of several
building blocks, introduces constraints for minimum build angle, as well as a penalty constraint
for building blocks with no support material below, so that the TO output is completely
printable. Additionally, orthotropic material properties are integrated in the optimization. In a
separate optimization algorithm, each building block is assumed to have its own fiber
orientation.",,,,,,
"['Dwivedi, Rajeev', 'Kovacevic, Radovan']",2020-02-17T14:21:31Z,2020-02-17T14:21:31Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79996', 'http://dx.doi.org/10.26153/tsw/7021']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Morphing Based Approach for Process Planning for Fabrication of Geometries and the Control of Material Composition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/762278fd-9bd9-48d2-8ec8-fc8bcca9ce7f/download,,"The inherent limitation of most of the solid freeform fabrication is the deposition in form
of layers. Artificial imposition of the process for the desired geometric morphology and
the functional gradience of material limits the accuracy of the workpiece. Mathematical
morphing of geometry and the material gradience allows a smooth variation across the
part geometry and the material composition of the part. The paper describes a framework
for process planning and implementation of fabrication of geometries and control of the
material composition. Simulation results for the suggested approach are described in the
paper.",,,,,,
"['Saint John, David B.', 'Joshi, Sanjay B.', 'Simpson, Timothy W.', 'Qu, Meng', 'Rowatt, John David', 'Lou, Yucun']",2021-10-26T20:18:02Z,2021-10-26T20:18:02Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89575,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'Inconel 718', 'morphology', 'grain texture', 'as-deposited', 'heat treated']",Morphology and Grain Texture in As-Deposited and Heat Treated Inconel 718 Structures Produced using Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/65dc8f17-3cb5-4228-b555-7e80070dfcec/download,University of Texas at Austin,"With increasing interest in the use of powder bed fusion (PBF) processes for additive
manufacturing, understanding the relationship between as-deposited and heat treated states and
the intrinsic anisotropy of fabricated parts has become critical for its successful application. This
phenomenon has been studied and reported extensively for Inconel 718 parts fabricated using
PBF for aerospace applications, but few reports exist on the morphology and grain texture of
Inconel 718 parts fabricated for oil and gas applications, which have different demands. This
work demonstrates that the anisotropy in Inconel 718 parts produced using laser-based PBF is
not entirely removed by subsequent heat treatments, and it may be an artifact of the as-deposited
grain structure, whose elongated grains may stretch through several melt pools. The as-built
material is observed to exhibit some texturing, with (001) being the preferential growth direction.
Despite some residual anisotropy, heat treatments are sufficient to provide material qualities that
meet specification, even without the use of a HIP (hot isostatic pressing) step. It is hypothesized
that similarly elongated grain structures may explain the anisotropy observed in other materials
systems employed in PBF additive manufacturing processes.",,,,,,
"['Taylor, C. Martin', 'Childs, T.H.C.', 'Hauser, C.']",2019-10-25T16:03:04Z,2019-10-25T16:03:04Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77440', 'http://dx.doi.org/10.26153/tsw/4529']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Morphology,Morphology of Direct SLS-Processed Stainless Steel Layers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3524c212-fd11-471c-9e2e-435da8c6b823/download,,"This paper discusses work done to analyse the shape of stainless steel layers generated
by direct selective laser sintering (SLS). Laser power, scan spacing and scanning speed have
been varied, to investigate their effect on geometry. The relationship between scanning
parameters and the qualities of sintered parts (dimensional uniformity, porosity and scanned
track shape) is described. A PC-based finite element code, developed to simulate SLS, has
been modified to match the conditions of experiments discussed above. A comparison is made
between computer-generated and experimentally-generated parts.",,,,,,
"['Jouaneh, Musa', 'Stucker, Brent']",2019-11-20T15:44:22Z,2019-11-20T15:44:22Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78460', 'http://dx.doi.org/10.26153/tsw/5545']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Fabrication,A Motion Planning Approach for Fabrication of Complex 3-D Shapes in a LENS� Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/751a38c7-7064-4e82-b461-0b1e5aa40797/download,,"This paper discusses an approach for planning the motion of the laser deposition
head relative to the part for fabrication of complex 3-D shapes such as parts with
overhangs, branches, and internal cavities in direct metal deposition processes such as the
LENS‘ process. The proposed approach is based on slicing the solid model of the part
into equal-thickness slices perpendicular to the normal build direction and formulating a
motion planning strategy based on the properties of these slices. The paper discusses the
four sub-approaches that are proposed to handle a variety of complex 3-D shapes parts.",,,,,,
"Jouaneh, Musa",2019-10-30T16:56:11Z,2019-10-30T16:56:11Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78193', 'http://dx.doi.org/10.26153/tsw/5282']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Cladding,Motion Planning for Cladding Operations in a 5-Axis LENS� Machine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d9102ce0-2d9e-466f-9ba4-f217b478b682/download,,"This paper presents a motion planning approach for some basic part shapes that
require 5-axis motion control in a LENS machine. The paper discusses an approach
that allows a cladding layer to be deposited on a cylindrical or a semi-spherical part for
re-build operations. For cylindrical parts, the deposited layer could take the form of a
tube, a spiral, or stepped/tappered tube. The approach allows arbitrary values for the
parameters of these layers, and automatically translates the part parameters into a motion
control program to run the LENS machine. The developed methodology was tested on
an Optomec 850 machine, and the results were successful.",,,,,,
"['Zong, Guisheng', 'Marcus, Harris L.']",2018-04-17T19:31:59Z,2018-04-17T19:31:59Z,1991,Mechanical Engineering,doi:10.15781/T2TD9NR56,http://hdl.handle.net/2152/64356,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SALD', 'pyrolytic']",Moving Boundary Transport Phenomena in Selective Area Laser Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e9bf252-57b5-4b2d-a768-f7960b3241f9/download,,"The overall selective area laser deposition process was modeled using the two-layer, three
dimensional solid phase heat transfer with the moving boundary condition considered, gas phase
mass transfer, and film growth coupled equations. A modified front-tracking finite difference
method was used to solve the moving boundary heat conduction in thick deposits. The results
correlate with the experimental observations.",,,,,,
"['Tagore, G.R.N.', 'Anjikar, Swapnil D.', 'Gopal, A. Venu']",2020-03-09T14:56:19Z,2020-03-09T14:56:19Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80191', 'http://dx.doi.org/10.26153/tsw/7210']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Fused Deposition Modeling,Multi Objective Optimisation of Build Orientation for Rapid Prototyping with Fused Deposition Modeling (FDM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/5286f4f8-8193-4c7c-b21d-01b9d64ca599/download,,"The ability to select the optimal orientation of build up is one of the critical factors since
it affects the part surface quality, accuracy, build time and part cost. Various factors to be
considered in optimisation of build orientation for FDM are build material, support material,
build up time, surface roughness and total cost. Experiments were carried out and results are
analysed for varying build orientation for primitive geometries like cylinder. An appropriate
weighting factor has been considered for various objective functions depending on the specific
requirement of the part while carrying out multi-objective optimisation. These analyses will help
process engineers to decide proper build orientation.",,,,,,
"['Liou, Frank', 'Ruan, Jianzhong', 'Sparks, Todd E.']",2021-09-30T19:10:58Z,2021-09-30T19:10:58Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88283', 'http://dx.doi.org/10.26153/tsw/15224']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Multi-Axis Planning System', 'hybrid laser metal deposition processes', 'multi-axis layered manufacturing', 'automated fabrication']",Multi-Axis Planning System (MAPS) for Hybrid Laser Metal Deposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4271887e-521a-49fc-a6e7-41bb57d25413/download,University of Texas at Austin,"This paper summarizes the research and development of a Multi-Axis Planning System (MAPS)
for hybrid laser metal deposition processes. The project goal is to enable the current direct metal
deposition systems to fully control and utilize multi-axis capability to make complex parts.
MAPS allows fully automated process planning for multi-axis layered manufacturing to control
direct metal deposition machines for automated fabrication. Such a capability will lead to
dramatic reductions in lead time and manufacturing costs for high-value, low-volume
components with high performance material. The overall approach, slicing algorithm, machine
simulation for planning validation, and the planning results will be presented.",,,,,,
"['Surovi, N.A.', 'Soh, G.S.']",2024-03-26T23:11:49Z,2024-03-26T23:11:49Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124444', 'https://doi.org/10.26153/tsw/51052']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'geometric defect']",MULTI-BEAD AND MULTI-LAYER PRINTING GEOMETRIC DEFECT IDENTIFICATION USING SINGLE BEAD TRAINED MODELS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7948b303-87b3-4d98-8191-6301f1d54b2d/download,University of Texas at Austin,"In Wire Arc Additive Manufacturing (WAAM), a geometric defect is a defect that creates voids in
the final printed part due to incomplete fusion between two non-uniform overlapping bead segments. Such
a defect posesthe onset of a severe problem during multi-bead prints. In our earlier work, a methodology
has been developed to construct machine learning (ML)-based modelsto identify geometrically defective
bead segments using acoustic signals. In this paper, we investigate the performance of these single-bead
segments trained defect detection model scalability for identifying voids during multi-bead prints. A
comparative study of the performance of a variety of ML models is explored based on Inconel 718 material
printing. The results show that the single bead segments-based defect identification model can effectively
identify defective and non-defective segments in both single-layer multi-bead printing and multi-layer multibead printing.",,,,,,
"['Heeling, T.', 'Zimmermann, L.', 'Wegener, K.']",2021-10-28T19:52:15Z,2021-10-28T19:52:15Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89684,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'multi-beam strategies', '316L']",Multi-Beam Strategies for the Optimization of the Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee1bf77f-af0f-45ed-b549-47a3e3755466/download,University of Texas at Austin,"The additive manufacturing of metal parts is of increasing importance for various industry
sectors, but processes like selective laser melting are still lacking of robustness especially in the
case of hard to process materials. The local adjustment of temperature fields around the melt pool
seems promising to decrease melt pool and stress related defects because the boundary conditions
can be tailored to positively influence the melt pool dynamics and lifetime as well as the
temperature gradients which are the main reason for distortion and cracking. Therefore a
selective laser melting laboratory machine was built up which features two independent lasers
and beam deflection units which are adapted to synchronization. To discuss the usability of
different synchronized multi-beam strategies for further process improvement, computational and
experimental evaluations are used to investigate the strategies‘ influences on the process
dynamics of the selective laser melting process.",,,,,,
"['Singh, Prabhjot', 'Dutta, Debasish']",2019-11-20T16:39:33Z,2019-11-20T16:39:33Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78478', 'http://dx.doi.org/10.26153/tsw/5563']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Layered Deposition,Multi-Direction Layered Deposition: An Overview of Process Planning Methodologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b9272a6-a9d9-4e35-a846-7995b17cffc2/download,,"Layered Manufacturing (LM) techniques build a part by adding thin layers of material. In many LM
processes overhangs require the deposition of sacrificial supports resulting in an increase in the
build time, wastage of material and costly post-processing. This has led to the development of LM
systems which can deposit material along multiple directions and eliminate the need for supports.
We survey the configurations of available multi-direction deposition systems. An overview of the
process planning challenges is presented. Literature on process planning methodologies is
reviewed.",,,,,,
"['Ding, D.', 'Pan, Z.', 'Cuiuri, D.', 'Li, H.', 'Larkin, N.', 'van Duin, S.']",2021-10-21T15:48:25Z,2021-10-21T15:48:25Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89402,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['robotic wire-feed additive manufacturing', 'multi-directional slicing', 'CAD models', 'STL models']",Multi-Direction Slicing of STL Models for Robotic Wire-Feed Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1299549-aaaf-4b26-9f13-2f44ecf25668/download,University of Texas at Austin,"Robotic wire-feed additive manufacturing technology is possible to directly fabricate
metallic overhangs without support structures through multi-direction deposition. To automatically
produce complex components with overhangs, an efficient multi-direction slicing algorithm to slice
CAD models into a set of proper layers is required. This paper reports the concept and
implementation of a new strategy for multi-direction slicing of CAD models represented in STL
format. An input STL model is firstly decomposed into sub-volumes using a simple curvature-based volume decomposition method. Accordingly, each sub-volume is able to be built in a single
direction. Then a depth-tree structure is introduced to regroup the decomposed sub-volumes and
provide the slicing sequences. Consequently, sub-volumes are separately sliced along their
associated appropriate build directions in sequence. The proposed multi-direction slicing strategy
is shown to be simple and efficient for STL models with sharp edges.",,,,,,
"['Bagchi, Amit', 'Beesley, Robert']",2018-10-03T15:38:18Z,2018-10-03T15:38:18Z,1994,Mechanical Engineering,doi:10.15781/T2HQ3SH86,http://hdl.handle.net/2152/68650,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Solid free-form fabrication', 'Photolithography', 'selective laser sintering']",Multi-layered Composites Using Photolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b532c87c-f94f-4147-b368-54e8627a7583/download,,"The mechanical properties of the parts made using solid freeform fabrication technologies are
limited by their resins used. Previous research has shown that the mechanical properties of these
parts can be enhanced substantially by using glass and fiber reinforcements. However, all of the
published data is for single layered composites, which does not demonstrate its feasibility to manufacture
multilayered real objects.
In this paper experiments carried out to build multi-layered parts with glass fiber tow as reinforcement
in a matrix of photopolymeric resin are described. These specimens are then tested in
uniaxial tension and three point bending to determine their improvement in mechanical properties.
The experimental data shows that the tensile strength and tensile modulus increased linearly with
the volume fraction of the fiber in the composite, thus demonstrating that the trends observed in
single layer composites can be also seen in multi-layered composites.",,,,,,
"['Bondi, Scott N.', 'Johnson, Ryan W.', 'Eikhatib, Tarek', 'Gillespie, Josh', 'Mi, Jian', 'Lackey, W. Jack']",2019-10-22T18:10:37Z,2019-10-22T18:10:37Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76331', 'http://dx.doi.org/10.26153/tsw/3420']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Deposition,Multi-Material and Advanced Geometry Deposition via Laser Chemical Vapor Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/067ed020-d727-4f1c-8022-5e7801349b8b/download,,"Laser Chemical Vapor Deposition (LCVD) as a manufacturing process holds the
potential to build compositionally and geometrically unique objects. Georgia Tech’s LCVD
system has been used in the past to create three-dimensional and laminate structures out of
carbon. Recently molybdenum and boron nitride were successfully deposited and upgrades to
the system have allowed for higher spatial resolutions and more varied geometric capabilities.
Upgrades include the addition of a fourth linear stage and implementation of an argon ion laser.
Detailed thermal and fluid modeling have provided more insight as to the important parameters
and characteristics of the LCVD process.",This work is supported by the National Science Foundation.,,,,,
"['Lipton, Jeffrey', 'Arnold, Dave', 'Nigl, Franz', 'Lopez, Nastassia', 'Cohen, Dan', 'Norén, Nils', 'Lipson, Hod']",2021-10-01T00:10:27Z,2021-10-01T00:10:27Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88304', 'http://dx.doi.org/10.26153/tsw/15245']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'additive manufacturing', 'food printing', 'food processing', 'multi-material constructs']",Multi-Material Food Printing with Complex Internal Structure Suitable for Conventional Post-Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c7c036fd-4f58-4b5a-95f3-5d59437c989b/download,University of Texas at Austin,"Solid Freeform Fabrication (SFF) of food provides an exciting application for
additive manufacturing technologies. A variety of materials has been used to
demonstrate food printing. However, these materials were not suited for
traditional food processing techniques (Baking, slow cooking, frying, etc) and
thus eliminating the majority of today‟s consumed food. We demonstrated new
materials suitable for baking, broiling and frying. Turkey, scallop, celery were
processed and modified using transglutaminase to enable them to be slow cooked
or deep-fried after printing. Mutli-material constructs of turkey meat and celery
were successfully printed. A cookie recipe was modified to be printable while
retaining shape during baking. By adding cocoa powder to the modified recipe a
second, visually and differently tasting material was created. A complex shape of
the cocoa modified material was printed within a block of the modified material.
The complex internal geometry printed was fully preserved during baking.",,,,,,
"['Patrick, Steven', 'Nycz, Andrzej', 'Noakes, Mark']",2021-11-18T16:49:21Z,2021-11-18T16:49:21Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90424', 'http://dx.doi.org/10.26153/tsw/17345']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['slicing software', 'slicing', 'process planning', 'multi-material', 'additive manufacturing', 'metal big area additive manufacturing', 'MBAAM', 'Oak Ridge National Laboratory']",Multi-Material Process Planning for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ec57a3cb-8475-4706-82f8-abb06dadb5a0/download,University of Texas at Austin,"A key process in additive manufacturing is converting a 3D model into a set of instructions
that a robot can parse and implement. This process is commonly referred to as slicing. Oak Ridge
National Laboratory’s (ORNL) Metal Big Area Additive Manufacturing (MBAAM) team at the
Manufacturing Demonstration Facility (MDF) has developed a slicing software that generates
instructions for multiple materials within the same part. The benefits of using multiple materials
are lower cost, fewer voids, and greater control over the print. However, a significant challenge
arose when the two different materials had different layer heights and bead widths. A layer of
complexity was added not only when the material changed from layer to layer, but also when
different materials were used within a single layer. These challenges were addressed by assigning
bead types and profile types to printing regions and layers, respectively.",,,,,,
"['Griffith, Michelle L.', 'Harwell, Lane D.', 'Romero, J. Tony', 'Schlienger, Eric', 'Atwood, Clint L.', 'Smugeresky, John E.']",2018-12-05T19:32:31Z,2018-12-05T19:32:31Z,1997,Mechanical Engineering,doi:10.15781/T21J97T99,http://hdl.handle.net/2152/71406,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'alloys']",Multi-Material Processing By Lens,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4255f87d-bc6c-4ddc-a267-18a095a0ea5e/download,,"During the past few years, solid freeform fabrication has evolved into direct fabrication of
metallic components using computer aided design (CAD) solid models. [1-4] Laser Engineered
Net Shaping (LENS™) is one such technique [5-7] being developed at Sandia to fabricate high
strength, near net shape metallic components. In the past two years a variety of components have
been fabricated using LENS™ for applications ranging from prototype parts to injection mold
tooling. [8]
To advance direct fabrication capabilities, a process must be able to accommodate a wide
range ofmaterials, including alloys and composites. This is important for tailoring certain
physical properties critical to component performance. Examples include graded deposition for
matching coefficient ofthermal expansion between dissimilar materials, layered fabrication for
novel mechanical properties, and new alloy design where elemental constituents and/or alloys are
blended to create new materials. In this paper, we will discuss the development ofprecise
powder feeding capabilities for the LENSTM process to fabricate graded or layered material parts.
We also present preliminary results from chemical and microstructural analysis.",,,,,,
"['Ott, M.', 'Zach, M.F.']",2021-09-30T13:44:32Z,2021-09-30T13:44:32Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88250', 'http://dx.doi.org/10.26153/tsw/15191']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive layer manufacturing', 'multi-material processing', 'material flexibility', 'material properties', 'hot work steel', 'tungsten carbide/cobalt']",Multi-Material Processing in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d3b43fdf-71cd-4be3-bb28-27ae19d9e319/download,University of Texas at Austin,"One of the most important advantages of additive layer manufacturing (ALM) is the ability to
produce parts with high geometric complexity in a very economical manner. However, only little
effort has been taken in order to enhance aspects of material flexibility of ALM. A modified
manufacturing process was developed and different stages concerning the dimensions of multi-material complexity are defined. The technological base being selective laser melting, two
varying metallic materials were fused within each layer. Therefore, a new recoating mechanism
for non-cohesive powders has been developed. To increase lifetime of tools with abrasive wear
environment, hot work steel and tungsten carbide/cobalt have been combined. A tooling insert
has been chosen as an example of application.",,,,,,
"['Chang, Chih-Chiang M.', 'Angelini, Thomas E.', 'Bova, Frank J.', 'Banks, Scott A.']",2021-11-30T20:09:48Z,2021-11-30T20:09:48Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90532', 'http://dx.doi.org/10.26153/tsw/17451']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['soft matter fabrication', '3D printing', 'robotics', 'additive manufacturing', 'multi-material']",Multi-Material Soft Matter Robotic Fabrication: A Proof of Concept in Patient-Specific Neurosurgical Surrogates,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb8affa1-43c8-4d57-9b7d-677601af93d2/download,University of Texas at Austin,"Soft matter 3D printing provides the capability to fabricate 3D structures by depositing
hydrogel inks in granular gel support material. To date, there has been little work reported using
this method to fabricate complex-shaped models with multiple materials in a timely fashion. The
aim of this project is to introduce recent research of multi-material soft-matter extrusion and
deposition for fast freeform fabrication of 3D structures, and to present a process for automating
the fabrication of patient-specific neuro-anatomic models for surgical training. A compact design
of multi-material extrusion printhead is described, which is capable of fabricating 3D structures
from multiple inks. This approach provides a fast and efficient way to convert a virtual volumetric
model into a physical extruded hydrogel structure using the multi-material soft-matter robotic
fabrication system. In addition to fabrication of neurosurgical phantoms, the capabilities we
describe may be useful in broader application contexts such as general soft matter robotic
fabrication, pharmaceutical testing, and extrusion-based bioprinting.",,,,,,
"['Arcaute, Karina', 'Zuverza, Nubia', 'Mann, Brenda', 'Wicker, Ryan']",2020-03-10T15:12:07Z,2020-03-10T15:12:07Z,8/27/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80214', 'http://dx.doi.org/10.26153/tsw/7233']",eng,2007 International Solid Freeform Fabrication Symposium,Open,stereolithography,Multi-Material Stereolithography: Spatially-Controlled Bioactive Poly(Ethylene Glycol) Scaffolds for Tissue Engineering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4b7ecd7-728b-48c2-8d44-65bc033a5adf/download,,"Challenges remain in tissue engineering to control the spatial and temporal mechanical and
biochemical architectures of scaffolds. Unique capabilities of stereolithography (SL) for
fabricating multi-material spatially-controlled bioactive scaffolds were explored in this work. To
accomplish multi-material builds with implantable materials, a new mini-vat setup was designed,
constructed and placed on top of the existing build platform to allow for accurate and selfaligning X-Y registration during fabrication. Precise quantities of photocrosslinkable solution
were added to and removed from the mini-vat using micro-pipettes. The mini-vat setup allowed
the part to be easily removed and rinsed and different photocrosslinkable solutions could be
easily removed and added to the vat to aid in multi-material fabrication. Two photocrosslinkable
hydrogel biopolymers, poly(ethylene glycol dimethacrylate) (PEG-dma, molecular wt 1,000) and
poly(ethylene glycol)-diacrylate (PEG-da, molecular wt 3,400), were used as the primary
scaffold materials, and controlled concentrations of fluorescently labeled dextran or bioactive
PEG were prescribed and fabricated in different regions of the scaffold using SL. The
equilibrium swelling behavior of the two biopolymers after SL fabrication was determined and
used to design constructs with the specified dimensions at the swollen state. Two methods were
used to measure the spatial gradients enabled by this process with multi-material spatial control
successfully demonstrated down to 500-µm. First, the presence of the fluorescent component in
specific regions of the scaffold was analyzed with fluorescent microscopy. Second, human
dermal fibroblast cells were seeded on top of the fabricated scaffolds with selective bioactivity,
and phase contrast microscopy images were used to show specific localization of cells in the
regions patterned with bioactive PEG. The use of multi-material SL and the relative ease of
conjugating different bioactive ligands or growth factors to PEG allows for the fabrication of
tailored three-dimensional constructs with specified spatially-controlled bioactivity.",,,,,,
"['Aguiló, M.A.', 'Warner, J.E.']",2021-11-04T19:55:55Z,2021-11-04T19:55:55Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90015', 'http://dx.doi.org/10.26153/16936']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['stochastic reduced order model', 'multi-material topology optimization', 'structural topology optimization', 'topology optimization', 'uncertainty']",Multi-Material Structural Topology Optimization Under Uncertainty via a Stochastic Reduced Order Model Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a3f59ee4-b806-4704-ad4d-2532346a5074/download,University of Texas at Austin,"This work presents a stochastic reduced order modeling approach for the solution of uncertainty aware, multi-material, structural topology optimization problems. Uncertainty aware structural topology optimization problems are computationally complex due to the number of model
evaluations that are needed to quantify and propagate design uncertainties. This computational
complexity is magnified if high-fidelity simulations are used during optimization. A stochastic reduced order model (SROM) approach is applied to 1) alleviate the prohibitive computational cost
associated with large-scale, uncertainty aware, structural topology optimization problems; and 2)
quantify and propagate inherent uncertainties due to design imperfections. The SROM framework
transforms the uncertainty aware, multi-material, structural topology optimization problem into a
deterministic optimization problem that relies only on independent calls to a deterministic analysis
engine. This approach enables the use of existing optimization and analysis tools for the solution
of uncertainty aware, multi-material, structural topology optimization problems.",,,,,,
"['Janaki Ram, G. D.', 'Robinson, C.', 'Stucker, B. E.']",2020-02-28T15:04:30Z,2020-02-28T15:04:30Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80108', 'http://dx.doi.org/10.26153/tsw/7129']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic consolidation,Multi-Material Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/316a7aa5-e0e8-41ef-a0e4-5cb9a653c56d/download,,"Ultrasonic consolidation (UC) is a recently developed direct metal solid freeform
fabrication process. While the process has been well-demonstrated for part fabrication in Al alloy
3003 H18, including with intricate cooling channels, some of the potential strengths of the
process have not been fully exploited. One of them is its flexibility with build materials and the
other is its suitability for fabrication of multi-material and functionally graded material parts with
enhanced functional or mechanical properties. Capitalizing on these capabilities is critical for
broadening the application range and commercial utilization of the process. In the current work,
UC was used to investigate ultrasonic bonding of a broad range of engineering materials, which
included stainless steels, Ni-base alloys, brass, Al alloys, and Al alloy composites. UC multimaterial part fabrication was examined using Al alloy 3003 as the bulk part material and the
above mentioned materials as performance enhancement materials. Studies were focused on
microstructural aspects to evaluate interface characteristics between dissimilar material layers.
The results showed that most of these materials can be successfully bonded to Al alloy 3003 and
vice versa using the ultrasonic consolidation process. Bond formation and interface
characteristics between various material combinations are discussed based on oxide layer
characteristics, material properties, and others.",,,,,,
"['Choi, S.H.', 'Cheung, H.H.']",2019-11-20T15:50:19Z,2019-11-20T15:50:19Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78462', 'http://dx.doi.org/10.26153/tsw/5547']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Multi-Material,A Multi-Material Virtual Prototyping System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e1b21a2f-a30a-4f31-aad4-bb8e933a0890/download,,"This paper proposes a virtual prototyping system for digital fabrication of multimaterial prototypes. It consists mainly of a topological hierarchy-sorting algorithm for
processing slice contours, and a virtual simulation system for visualisation and optimisation
of multi-material layered manufacturing (MMLM) processes. The topological hierarchysorting algorithm processes the hierarchy relationship of complex slice contours. It builds a
parent-and-son list that defines the containment relationship of the slice contours, and
subsequently arranges the contours in an appropriate sequence which facilitates optimisation
of toolpath for MMLM by avoiding redundant movements. The virtual simulation system
simulates MMLM processes and provides vivid visualisation of the resulting multi-material
prototypes for quality analysis and optimisation of the processes","The authors would like to acknowledge the Research Grant Council of the Hong Kong SAR
Government and the CRCG of the University of Hong Kong for their financial support for
this project.",,,,,
"['Espalin, David', 'Ramirez, Jorge', 'Medina, Francisco', 'Wicker, Ryan']",2021-10-06T21:56:33Z,2021-10-06T21:56:33Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88456', 'http://dx.doi.org/10.26153/tsw/15393']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'multi-materials', 'multi-technology', 'thermoplastic parts']","Multi-Material, Multi-Technology FDM System",Conference paper,https://repositories.lib.utexas.edu//bitstreams/80ce4603-a12c-4f42-81ed-544c1764f538/download,University of Texas at Austin,"A multi-material, multi-technology FDM system was developed and constructed to
enable the production of novel thermoplastic parts. Two legacy FDM systems were modified
and installed onto a single manufacturing system to allow the strategic, spatially controlled
thermoplastic deposition of multiple materials during the same build. Additionally, a build
process variation utilizing more than two extrusions tips was employed to deposit
thermoplastic materials using variable layer thicknesses and road widths. The hardware and
control software is discussed as well as the potential applications of multi-material polymeric
parts. Benefits of multiple material FDM include: 1) achieving aesthetic requirements by
using polymers of different colors, and 2) attaining desired properties (e.g., bulk
tensile/compressive/flexural strength, weight, thermal conductivity) by strategically
combining layers and regions within layers of polymers that display different properties.
Parts produced using the build process variation exhibited internal road with 1200 ± 39µm
road width and 497 ± 11µm layer height while the contours measured 269 ± 18µm road width
and 133 ± 3µm layer thickness. Additionally, for a 50.8mm by 50.8mm square section
(25.4mm tall), the build process variation required 4.0 hours to build while the original
strategy required 6.2 hours constituting a 35% reduction in build time.",,,,,,
"['Khalil, S.', 'Nam, J.', 'Darling, A.', 'Sun, W.']",2020-02-20T18:38:00Z,2020-02-20T18:38:00Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80038', 'http://dx.doi.org/10.26153/tsw/7060']",eng,2004 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,Multi-Nozzle Biopolymer Deposition for Freeform Fabrication of Tissue Constructs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c827f801-78dc-4ca1-add5-d5fe50d56f08/download,,"Advanced freeform fabrication techniques have been recently used for the construction of tissue
scaffolds because of the process repeatability and capability of high accuracy in fabrication
resolution at the macro and micro scales. Among many applicable tissue scaffolding materials,
polymeric materials have unique properties in terms of the biocompatibility and degradation, and
have thus been widely utilized in tissue engineering applications. Hydrogels, such as alginate,
has been one of the most important polymer scaffolding materials because of its biocompatibility
and internal structure similarity to that of the extracellular matrix of many tissues, and its
relatively moderate processing. Three-dimensional deposition has been an entreating freeform
fabrication method of biopolymer and particularly hydrogel scaffolds because of its readiness to
deposit fluids at ambient temperatures. This paper presents a recent development of biopolymer
deposition based freeform fabrication for 3-diemnsinal tissue scaffolds. The system
configuration of multi-nozzles used in the deposition of sodium alginate solutions and Poly-?-
Caprolactone (PCL) are described. Studies on polymer deposition feasibility and structural
formability are conducted, and the preliminary results are presented.",,,,,,
"['Aboutaleb, Amir M.', 'Bian, Linkan', 'Shamsaei, Nima', 'Thompson, Scott M.', 'Rao, Prahalad K.']",2021-10-27T21:25:01Z,2021-10-27T21:25:01Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89619,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'multi-objective optimization', 'fused filament fabrication', 'geometry accuracy optimization', 'design of experiments']",Multi-Objective Process Optimization of Additive Manufacturing: A Case Study on Geometry Accuracy Optimization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4f750348-5ab4-4880-91aa-0268c4bb973a/download,University of Texas at Austin,"Despite recent research efforts improving Additive Manufacturing (AM) systems, quality and reliability
of AM built products remains as a challenge. There is a critical need to achieve process parameters optimizing
multiple mechanical properties or geometry accuracy measures simultaneously. The challenge is that the
optimal value of various objectives may not be achieved concurrently. Most of the existing studies aimed to
obtain the optimal process parameters for each objective individually, resulting in duplicate experiments and
high costs. In this study we investigated multiple geometry accuracy measures of parts fabricated by Fused
Filament Fabrication (FFF) system. An integrated framework for systematically designing experiments is
proposed to achieve multiple sets of FFF process parameters resulting in optimal geometry integrity. The
proposed method is validated using a real world case study. The results show that optimal properties are
achieved in a more efficient manner compared with existing methods.",,,,,,
"['Paudel, Basil J.', 'Masoomi, Mohammad', 'Thompson, Scott M.']",2021-11-30T19:50:41Z,2021-11-30T19:50:41Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90527', 'http://dx.doi.org/10.26153/tsw/17446']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser-powder bed fusion', 'optimization', 'heat sink', 'topology', 'fin design']",Multi-Objective Topology Optimization of Additively Manufactured Heat Exchangers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/940219e2-230b-4a7e-a6eb-3687ed6ed45d/download,University of Texas at Austin,"The higher design flexibility offered by additive manufacturing (AM) allows for radical
improvements in the design and functionality of legacy parts. In this study, a flat-plate heat
exchanger is designed and optimized using the ANSYS topology optimization module. Unlike
conventional numerical optimization tools, the current optimization approach employs multiple
objective functions, including mass reduction and maximization of heat transfer efficiency. Two
unique, initial designs were used for ‘seeding’ the multi-objective topology optimization (TO)
routines and the results are compared and discussed. Topology design and operating (boundary
condition) variables were varied to elucidate major design sensitivities. The predicted heat transfer
within the topology-optimized parts was validated using separate numerical methods. Constraints
related to flow pressure drops and additive manufacturability were enforced. In both cases, the
optimal design performed significantly better than the conventional heat exchanger in terms of
thermal efficiency per unit mass.",,,,,,
"['MN, Kishore', 'Qian, Dong', 'Li, Wei']",2024-03-26T20:02:43Z,2024-03-26T20:02:43Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124384', 'https://doi.org/10.26153/tsw/50992']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'low temperature', 'sub-freezing deposition', 'computational fluid dynamics', 'multiphysics modeling']",MULTI-PHYSICS MODELING OF LOW-TEMPERATURE DIRECTED ENERGY DEPOSITION OF STAINLESS STEEL 316L,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2390a86e-ee67-430a-abe9-4ceee2a538db/download,University of Texas at Austin,"The Directed energy deposition (DED) process is greatly influenced by the ambient temperature
at on-site repair. In Northern Hemisphere locations, DED is particularly influenced by sub-freezing
temperatures. However, its influence on the process is not yet studied. This critical gap is fulfilled
in this research through a multi-physics computational fluid dynamics (CFD) modeling of the lowtemperature DED of the SS316L powders. The model is validated with test cases: −3°𝐶 for subfreezing and 20°𝐶 for room temperature cases using a cryogenic DED platform. The modeling
involves powder spray, local melting, rapid cooling, solidification, evaporation, and fluid-gas
interactions. The results show, at sub-freezing, the molten pool is ~63% bigger with the maximum
temperature reduced by ~9.5%. The deposition saw an increase in width by ~8.6% and height by
~26% than the room temperature case. Overall, the versatile modeling-experimental platform helps
study cryogenic DED cases for in-space additive manufacturing.",,,,,,
"['Cheng, Bo', 'Li, Xiaobai', 'Tuffile, Charles', 'Ilin, Alexander', 'Willeck, Hannes', 'Hartel, Udo']",2021-11-15T21:02:59Z,2021-11-15T21:02:59Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90270', 'http://dx.doi.org/10.26153/tsw/17191']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'SLM', 'discrete element method', 'DEM', 'powder bed packing', 'melt pool', 'computational fluid dynamics', 'CFD', 'volume of fluid', 'VOF']",Multi-Physics Modeling of Single Track Scanning in Selective Laser Melting: Powder Compaction Effect,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cfb54c01-7c1f-490b-bff0-ab2a35984b4d/download,University of Texas at Austin,"In this work, a microscale computational fluid dynamics (CFD) model was developed for
selective laser melting (SLM) process simulation using FLOW3D to study the effect of powder
bed recoating methods on melt pool characteristics. The discrete element method (DEM) was used
to simulate both the blade and the roller-compaction recoating processes, where layers of powder
particles with different sizes were generated on a solid substrate. Melt pools propagating through
the powder beds were simulated using the Volume of Fluid (VOF) method that tracks the free
surface evolution of melt pools that are produced when a Gaussian distributed moving laser heat
source, with given process parameters, irradiates the powder bed. Thermal and fluid material
properties were incorporated in the model to improve simulation accuracy, and melt pool
validation from single-track laser scanning simulation was performed.",,,,,,
"['Lehder, E.F.', 'Ashcroft, I.A.', 'Wildman, R.D.', 'Maskery, I.', 'Cantu, L.R.']",2021-11-30T20:07:44Z,2021-11-30T20:07:44Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90531', 'http://dx.doi.org/10.26153/tsw/17450']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['bone scaffolds', 'computational modelling', 'minimal surfaces', 'tissue regeneration', 'level set method', 'multi-scale']",A Multi-Scale Computational Model to Predict the Performance of Cell Seeded Scaffolds with Triply Periodic Minimal Surface Geometries,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b59b3bf-a5d7-4d73-a623-e8afc8f0d7be/download,University of Texas at Austin,"Bone scaffolds are required to replace the painful and dangerous process of bone grafting, currently the
gold standard for treating open bone fractures. Tissue engineering scaffolds work best when there is a high
amount of surface area for biological cells to attach. Triply Periodic Minimal Surface (TPMS) geometries offer
high ratios of surface area per volume. However, it is not yet clear which TPMS cell type would yield the fastest
bone growth rate. In this study, we used a three-dimensional multi-scale model to predict the performance of
scaffolds with four TPMS unit cell types (Primitive, Gyroid, Diamond and Lidinoid). At the micro-scale, the
model simulates curvature-dependent tissue growth, while at the macro-scale the model uses FEA to ensure the
construct stiffness is acceptable. The Lidinoid unit cell type was found to yield the most bone growth after
40 days while also ensuring an acceptable scaffold stiffness.",,,,,,
"['Botelho, L.', 'van Blitterswijk, R.H.', 'Khajepour, A.']",2021-12-07T18:32:07Z,2021-12-07T18:32:07Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90751', 'http://dx.doi.org/10.26153/tsw/17670']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser additive manufacturing', 'machine learning', 'convolutional neural network']",Multi-track Geometry Prediction in Powder Fed Laser Additive Manufacturing Using Machine Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df4ec261-900c-48e6-b38a-95b9d49f5197/download,University of Texas at Austin,"Laser additive manufacturing (LAM) allows for complex geometries to be fabricated
without the limitations of conventional manufacturing. However, LAM is highly sensitive to small
disturbances, resulting in variation in the geometry of the produced layer (clad). Therefore, in this
research a monitoring algorithm is discussed with the capability of predicting the geometry of
multiple tracks of added material. Though imaging can be used to measure the geometry of the
melt pool during LAM, the appearance of the melt pool changes in multi-track processes due to
the previous layers causing measurement errors. Hence, a machine learning algorithm may be able
to accommodate for the changing melt pool appearance to improve accuracy. Images can be
captured during LAM with visible-light and infrared sensors which may provide sufficient
information for the geometry to be predicted. A convolutional neural network (CNN) can then use
these images to estimate the geometry (height and width) during LAM processes.",,,,,,
"['Folgar, C.E.', 'Folgar, L.N.', 'Cormier, D.']",2021-10-07T18:18:15Z,2021-10-07T18:18:15Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88498', 'http://dx.doi.org/10.26153/tsw/15432']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'direct printing', 'multifunctional material', 'part strength', 'electrical conductivity']",Multifunctional Material Direct Printing for Laser Sintering Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93cc0a72-bb1c-4767-89aa-9767bca10722/download,University of Texas at Austin,"The research reports the development of advanced techniques for the direct print of
materials into parts made by laser sintering. The present invention provides for the production of
three-dimensional objects with improved build and support materials. The direct printed material
may be metals, elastomers, ceramic, or any other material, which is typically different than the
laser sintering material. Aspects of the technique include direct printed materials within laser
sintered parts to improve part strength, provide multi-materials, provide electrical conductivity,
and provide other desirable benefits to the part.",,,,,,
"['Johannes, S.J.', 'Keicher, D.M.', 'Lavin, J.M.', 'Secor, E.B.', 'Whetten, S.R.', 'Essien, M.']",2021-11-09T18:51:19Z,2021-11-09T18:51:19Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90116', 'http://dx.doi.org/10.26153/tsw/17037']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['aerosol jet printing', 'direct-write printing', 'circuit elements', 'toroidal inductor', 'additive manufacturing']",Multimaterial Aerosol Jet Printing of Passive Circuit Elements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6bf96d30-27b2-4df2-af5c-bf00b1c73c9c/download,University of Texas at Austin,"Recent advances in additive manufacturing technologies present opportunities for
rethinking the design and fabrication of electronic components. An area of considerable interest
for electronic printing is the production of multi-layered, multi-material passive components. This
research focuses on the design and fabrication of a toroidal microinductor using a digital, direct-write printing platform. The toroidal inductor has a three layer design with a dielectric and core
material printed in between the lower and upper halves of the conductive coil. The results of this
work are discussed, including printer, ink, and processing requirements to successfully print the
multi-layer, multi-material component. The inductance of several successful printed devices is
measured and compared to predicted values. Overall, the results and lessons of this work provide
guidance for future work in this growing field.",,,,,,
"['Geiger, Martin', 'Greul, Matthias', 'Steger, Wilhelm', 'Sindel, Manfred']",2018-09-26T16:48:03Z,2018-09-26T16:48:03Z,1994,Mechanical Engineering,doi:10.15781/T2348H18X,http://hdl.handle.net/2152/68581,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Multiphase Jet Solidification', 'RP Technologies', '3D Modeler of Stratasys']",Multiphase Jet Solidification - a new process towards metal prototypes and a new data interface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/34bc59a2-8ae9-463e-bc49-722b963e76fd/download,,"The production of metallic and ceramic parts with RP technologies is requested. Multiphase Jet Solidification (MJS) is a process which reveals good results to develop a
commercial system due to this task. Low viscous materials (liquefied substances or
powder-binder~pastes) are extruded through an x-y-z~ontrolled jet and parts of different
materials e.g. stainless steel are fabricated layer by layer up to the final extension. basic
principle of the process and the current results will be presented. A slice format was
designed for MJS, but it is also usable for other technologies. The is
development of a general slice interface for RP.",,,,,,
"['Rangapuram, M.', 'Yang, M.', 'Babalola, S.', 'Newkirk, J.W.', 'Bartlett, L.N.', 'Liou, F.F.', 'Chandrashekhara, K.']",2023-03-30T16:12:24Z,2023-03-30T16:12:24Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117698', 'http://dx.doi.org/10.26153/tsw/44577']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Laser powder bed fusion,A Multiphysics Modeling Approach to Assess the Powder Bed Characteristics of High Strength Steel in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f70de131-790e-4c59-b60d-7511af969643/download,,"Selective laser melting (SLM) is a type of additive manufacturing technique which uses a powder 
bed to form complex metal parts in a layer-by-layer process. The density of the powder bed in 
SLM affects the mechanical properties of the produced part. Good powder packing results in a 
higher powder bed density which in turn influences the quality of the produced part. In this work, 
a computational fluid dynamics (CFD) model was developed for the SLM process using Flow 3D 
software to study the effect of powder bed density on the melt pool characteristics of high strength 
steel. Discrete element method (DEM) was used to generate powder beds with realistic powder 
properties. The realistic powder properties of AF9628 were obtained using JMatPro software. The 
powder beds were irradiated with a moving laser heat source to study the melt pool characteristics. 
These models were validated with experimental results.",,,,,,
"['Caglar, H.', 'Liang, A.', 'Mumtaz, K.']",2024-03-26T21:35:59Z,2024-03-26T21:35:59Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124421', 'https://doi.org/10.26153/tsw/51029']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'diode area melting', 'Ti-6Al-4V', 'additive manufacturing']",MULTIPLE 450 nm DIODE LASER PROCESSING OF TI64 POWDER,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aae75500-33e1-4a25-8eaf-dca7c7aecca2/download,University of Texas at Austin,"Diode Area Melting (DAM) presents an alternative approach to traditional Laser Powder
Bed Fusion (PBF-LB/M) approaches, integrating multiple individually addressable low-power
fibre-coupled diode lasers into a laser head; these traverse across a powder bed to melt powdered
feedstock. DAM research to date has focused on using low-power 808 nm lasers to process Ti6Al-4V (Ti64) powder. This work focuses on using multiple short wavelengths 450 nm 4W lasers
to process Ti64 feedstock. Previous studies found that when processing Ti64, absorption was 11%
higher using 450 nm lasers when compared to using 808 nm lasers and 14% higher than 1064nm
laser. This work demonstrated the potential to use shorter wavelength lasers in DAM/LPBF for
improved melting efficiency. Also, it aimed to examine the impact of 450 nm diode lasers on Ti64
and generate a parameter map for this material. It was found that low power (4W) multiple 450
nm diode lasers can successfully melt the Ti64 for AM applications with above 95% density.",,,,,,
"['Leite, M.', 'Frutuoso, N.', 'Soares, B.', 'Ventura, R.']",2021-11-15T22:01:50Z,2021-11-15T22:01:50Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90286', 'http://dx.doi.org/10.26153/tsw/17207']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['large parts', 'FDM', 'collaborative deposition heads']",Multiple Collaborative Printing Heads in FDM: The Issues in Process Planning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1430a740-68fb-47b8-9e62-7117d98246c7/download,University of Texas at Austin,"One of the main drawbacks of large-scale FDM is fabrication time, due to the use of a single deposition
head. In this paper we propose a novel approach to tool-path generation for a system with multiple collaborative
independent deposition heads. This system allows the size of the parts to increase considerably in comparison to
regular FDM systems without the corresponding time increase. However, to enable the tool-path generation, the
conventional process planning must be changed.
Once the machine configuration is defined, (e.g. number and size of heads), the regions are attributed to
each head as either static or dynamic. Then the layer is divided into domains, assigned to each head. A
centralized tool-path planner then generates tool-paths, accounting for collisions and optimizing the fabrication
time in the layer. The process repeating for all layers.
Examples of this approach show reduced fabrication time and larger part dimensions than conventional
systems.",,,,,,
"['Wicker, Ryan', 'Medina, Francisco', 'Elkins, Chris']",2020-02-17T15:40:23Z,2020-02-17T15:40:23Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/80013', 'http://dx.doi.org/10.26153/tsw/7038']",eng,2004 International Solid Freeform Fabrication Symposium,Open,"['multiple material stereolithography', 'rapid prototyping', 'micro-stereolithography']",Multiple Material Micro-Fabrication: Extending Stereolithography to Tissue Engineering and Other Novel Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61f2ec11-728b-433b-a70b-33cc55ffc399/download,,"A design for modifying an existing 3D Systems stereolithography (SL) apparatus 250/50 was
developed to accommodate multiple material fabrication for building multi-material, multifunctional and multi-colored prototypes, models and devices. The machine was configured for
automated access to an intermediate washing, curing, and drying unit that eliminated
contamination between material vats and maintained accurate platform registration throughout
the build process. Three vats were arranged on a rotating vat carousel, and each vat was adapted
to actively maintain a uniform, desired level of material by including a recoating device and a
material fill and removal system. A single platform was attached to an elevator mechanism (zstage) to traverse the platform to and from the vats and the washing, curing, and drying unit. The
platform was mounted to the z-stage via an automated rotary stage to rotate the platform about a
horizontal axis, thus providing angled building, washing, curing, and drying capabilities. A
horizontal traversing mechanism was also designed to be optionally included to facilitate
manufacturing between multiple SL cabinets, related SL apparatuses and/or other alternative
manufacturing technologies. For micro-fabrication, linear and rotary stages were selected that
provided ±1.0 µm repeatability and 0.1 µm resolution and ±2 arc sec repeatability and 0.13 arc
sec resolution, respectively. The multi-material SL design presented here is capable of utilizing
existing SL resins for manufacturing multiple material mechanically and electrically functional
models as well as hydrogels, biocompatible materials, and bioactive agents for a variety of biofunctional, implantable tissue engineering applications including nerve regeneration and guided
angiogenesis.",,,,,,
"['Choi, Jae-Won', 'MacDonald, Eric', 'Wicker, Ryan']",2021-09-29T20:12:08Z,2021-09-29T20:12:08Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88210', 'http://dx.doi.org/10.26153/tsw/15151']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['microstereolithography (µSL)', 'multi-material fabrication']",Multiple Material Microstereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef014224-446f-4342-ab0d-d1b597ef4ddd/download,University of Texas at Austin,"We have previously described the development of a µSL system using a Digital Micromirror Device
(DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for
crosslinking the photoreactive polymer solution. The µSL system was designed with x-y resolution of
~2 µm and a vertical (z) resolution of ~1 µm (with practical limitations on vertical resolution of ~30
µm resulting from the current laboratory setup). This µSL system is capable of producing real three-dimensional (3D) microstructures, which can be used in micro-fluidics, tissue engineering, and various
functional micro-systems. As has been explored and described in µSL, many benefits will potentially
be derived from producing multiple material microstructures in µSL. One particular application area of
interest is in producing multiple material micro-scaffolds for tissue engineering. In this work, a
method for multiple material µSL fabrication was developed using a syringe pump system to add
material to a small, removable vat designed for the µSL system. Multiple material fabrication was
accomplished by manually removing the vat and draining the current material, rinsing the vat, placing
the vat back into the system, and dispensing a prescribed volume in the vat using the syringe pump.
Layer thicknesses less than ~30 µm were achieved using this process. To demonstrate this system,
several multiple material microstructures were produced, and we believe multi-material µSL represents a
promising technology for producing functional microstructures with composite materials.",,,,,,
"['Snarr, Scott E.', 'Najera, Andres', 'Beaman, Joseph Jr.', 'Haas, Derek']",2021-12-07T18:30:25Z,2021-12-07T18:30:25Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90750', 'http://dx.doi.org/10.26153/tsw/17669']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['mutliple-material powder bed fusion', 'machine development', 'nozzle-based powder deposition', 'cross-contamination', 'design of experiments']",Multiple-Material Powder Bed Fusion Machine Development: Reducing Cross-Contamination between Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0295547c-bf90-4cef-b82a-8174e719c51a/download,University of Texas at Austin,"Powder bed fusion is an additive manufacturing technology capable of producing fully
dense, high strength parts with complex geometries. However, it is currently only able to
fabricate parts comprised of a single material. Multiple-material capabilities would allow for an
added level of design complexity and the matching of material properties to the functional
requirements of a part. In order to achieve this, a full redesign of the current powder deposition
system is required. Previous attempts to implement multiple-material powder deposition systems
encountered issues with controlling the dimensional accuracy in the build direction and cross-contamination between materials. This research integrates an angled blade leveling mechanism
along with a nozzle-based powder deposition system to solve these problems. A design of
experiments was run to identify significant leveling parameters and to quantify material cross-contamination. A deposition and leveling system that creates a uniform height multiple-material
powder bed with no significant cross-contamination of materials is demonstrated.",,,,,,
"['Meisel, Nicholas A.', 'Gaynor, Andrew', 'Williams, Christopher B.', 'Guest, James K.']",2021-10-12T18:48:06Z,2021-10-12T18:48:06Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88717', 'http://dx.doi.org/10.26153/tsw/15651']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'PolyJet', '3D printing', 'multiple materials', 'compliant mechanisms', 'material jetting']",Multiple-Material Topology Optimization of Compliant Mechanisms Created via Polyjet 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/097f6036-ff64-454d-a15a-cb5524dacf6f/download,University of Texas at Austin,"Compliant mechanisms are able to transfer motion, force, and energy using a monolithic
structure without discrete hinge elements. The geometric design freedoms and multi-material
capability offered by the PolyJet 3D printing process enables the fabrication of compliant
mechanisms with optimized topology. The inclusion of multiple materials in the topology
optimization process has the potential to eliminate the narrow, weak, hinge-like sections that are
often present in single-material compliant mechanisms. In this paper, the authors propose a
design and fabrication process for the realization of 3-phase, multiple-material compliant
mechanisms. The process is tested on a 2D compliant force inverter. Experimental and
theoretical performance of the resulting 3-phase inverter is compared against a standard 2-phase
design.",,,,,,
"['Arrieta, Edel', 'Mireles, Jorge', 'Stewart, Calvin', 'Carrasco, Cesar', 'Wicker, Ryan B.']",2021-11-04T19:14:02Z,2021-11-04T19:14:02Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90006', 'http://dx.doi.org/10.26153/16927']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['cellular solids', 'unit-cell', 'EBM', 'Ti-6Al-4V', 'digital image correlation', 'microstructure']",Multiscale Analysis of Cellular Solids Fabricated by EBM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5711d80f-e0d5-4621-ac8e-112109d36d8f/download,University of Texas at Austin,"Additive Manufacturing technologies such as Electron Beam Melting are empowering
individuals to develop novelty materials by introducing hierarchical levels into solids. Features
from the introduced architectures and the manufacturing technology grant these metamaterials
with mechanical performances not commonly seen in standard solids. Thus, the response of
cellular metals can now be manipulated. In general, the reported research on lattices focuses on
very specific topics such as microstructure, geometry and orientation, giving the impression of
isolated knowledge. However, the response of these metamaterials is the result of a complex
multiscale interaction between these and other factors ranging from the microstructure of the
constitutive solid, up to the cell topology. Intended as a one-stop introductory document for a new
branch of material designers, the major factors affecting the response of cellular metals are
identified, classified and merged into a multiscale discussion supported with evidence from a series
of experiments including ASTM standard tests of EBM Ti-6Al-4V standard and lattice specimens,
accompanied by failure analysis. The testing features digital image correlation (DIC) for
measuring deformations, strain fields, as well as Poisson and shear effects, becoming a critical tool
for the advanced characterization of specimens, especially those with complex geometries that
normally would require specific instrumentation. Among these multiple determinants;
microstructure, manufacturing orientation, manufacturing process, Maxwell’s stability criterion,
and other geometrical features are discussed for the comprehensive understanding of two lattice
designs presented herein. Lastly, Illustrative examples of how the stress-strain curves are helpful
in diagnosing design features to start reverse engineering processes, and a summary of the
determinants effects are included.",,,,,,
"['Seepersad, Carolyn Conner', 'Shahan, David', 'Madhavan, Kaarthic']",2020-03-10T14:23:29Z,2020-03-10T14:23:29Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80209', 'http://dx.doi.org/10.26153/tsw/7228']",eng,2007 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,Multiscale Design for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dbb183e4-0a78-40e1-816d-d4c6c34c19bf/download,,"One of the advantages of solid freeform fabrication is the ability to fabricate complex
structures on multiple scales, from the macroscale features of an overall part to the
mesoscale topology of its internal architecture and even the microstructure or
composition of the constituent material. This manufacturing freedom poses the challenge
of designing across these scales, especially when a part with designed mesostructure is
part of a larger system with changing requirements that propagate across scales. A setbased multiscale design method is presented for coordinating design across scales and
reducing iterative redesign of SFF parts and their mesostructures. The method is applied
to design a miniature unmanned aerial vehicle system. The system is decomposed into
disciplinary subsystems and constituent parts, including wings with honeycomb
mesostructures that are topologically tailored for stiffness and strength and fabricated
with selective laser sintering. The application illustrates how the design of freeform parts
can be coordinated more efficiently with the design of parent systems.",,,,,,
"['Morris, C.', 'Debeau, D.', 'Dressler, A.', 'Seepersad, C.C.']",2021-11-03T22:36:10Z,2021-11-03T22:36:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89952,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['operating parameters', 'multisystem model', 'optimization', 'solar sintering system']",Multisystem Modeling and Optimization of Solar Sintering System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/403609b6-fe09-492a-92e7-7ad494a7f597/download,University of Texas at Austin,"In developing countries, the production of building materials such as tile and brick,
require large amounts of non-renewable energy and/or time to produce. Previous work has
shown that solar sintering machines are capable of producing ceramic parts in a viable amount of
time using only solar energy. The systems focus sunlight on a bed of sand where the intensity is
sufficient for sintering. Then by moving the sand bed, parts of complex geometry are formed.
This study aims to identify optimal operating parameters for the solar sintering system by
solving a multi-objective, multisystem model. The subsystems considered are the dynamics of
the sand bed, optics of focusing sunlight, and heating of the sand bed. To reduce the
computational expense, a Kriging surrogate model was employed to model the heating of the
sand bed. Finally by performing a tradeoff analysis of production time and part quality, candidate
operating parameters were identified.",,,,,,
"['Nath, P.', 'Hu, Z.', 'Mahadevan, S.']",2021-11-02T20:38:05Z,2021-11-02T20:38:05Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89891,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['uncertainty quantification', 'additive manufacturing', 'multi-level', 'simulation']",Mutli-Level Uncertainty Quantification in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9e55226-ee62-4dd4-851a-610a0d6ddecd/download,University of Texas at Austin,"Quantifying the uncertainty in additive manufacturing (AM) process plays an important
role in the quality control of additively manufactured products. This work presents an uncertainty
quantification (UQ) framework to quantify the uncertainty of material microstructure due to
multiple uncertainty (aleatory and epistemic) sources present in the AM simulation process. A
multi-scale, multi-physics simulation model is first developed to simulate the melting and
solidification processes. The melt pool profile obtained from macro-scale finite element analysis
is coupled with a micro-scale cellular automata model to predict the microstructure evolution
during solidification. Based on the simulation model, various sources of uncertainty are aggregated
to quantify the uncertainty in the grain size distribution of the microstructure. The contributions of
the various sources of uncertainty to the uncertainty of microstructure grain size distribution are
analyzed using variance-based global sensitivity analysis. The results show that the proposed
approach can effectively perform UQ of the AM process and the uncertainty in the grain size
distribution is mainly affected by material properties and grain growth parameters.",,,,,,
"['Behera, Dipankar', 'Roy, Nilabh K.', 'Foong, Chee S.', 'Cullinan, Michael']",2021-11-16T15:19:04Z,2021-11-16T15:19:04Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90310', 'http://dx.doi.org/10.26153/tsw/17231']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['powder bed deposition', 'slot-die coating', 'nanoparticle', 'microscale selective laser sintering', 'µ-SLS']",Nanoparticle Bed Deposition by Slot Die Coating for Microscale Selective Laser Sintering Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/74545fbd-0ffc-4ec7-a4ce-87523eb45b97/download,University of Texas at Austin,"The minimum feature size in most commercially available metal additive manufacturing
(AM) processes is limited to ~100 microns which poses a fundamental challenge in fabricating
complex 3D micro-components. The authors have developed a microscale selective laser sintering
(µ-SLS) process with the goal of fabricating these microproducts with 1µm minimum feature size
resolution. To achieve near-net shaped sintered features, the powder bed layer should not be more
than one micron thick. This paper presents the development and testing of a powder bed deposition
mechanism using a slot-die coater. Metallic nanoparticles uniformly dispersed in a solvent were
used in this study. A viscocapillary coating model was used to predict the wet thickness of the
powder bed based on the coating gap. Experimental results revealed that uniform sub-micron layer
thicknesses were achieved by optimizing the process parameters such as flow rate, coating speed,
coating gap, and die gap. The novel approach discussed in this paper enables the implementation
of a robust coating mechanism for high throughput AM.",,,,,,
"['Roth, J.-P.', 'Sulak, I.', 'Chlup, Z.', 'Fischer-Buhner, J.', 'Krupp, U.', 'Jahns, K.']",2024-03-26T16:40:48Z,2024-03-26T16:40:48Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124365', 'https://doi.org/10.26153/tsw/50973']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['NiCu', 'Alloy 400', 'nanoparticle', 'laser powder bed fusion', 'additive manufacturing']",NANOPARTICLE-MODIFICATION OF NICU-BASED ALLOY 400 FOR LASER POWDER BED FUSION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/73c6858b-e536-4e95-b001-c250f94cb225/download,University of Texas at Austin,"NiCu-based Alloy 400 is a material being frequently used in corrosive environments
wherefore it is applied in several industries like the maritime sector or chemical processing [1].
Numerous functional parts made of this alloy, like heat exchangers or liquid-carrying tubes for
instance, may withstand harsh environments to a certain extend but still, at high temperatures and
especially in carbon-rich atmospheres, component failure occurs due to poor metal dusting and
creep resistance [2–5]. Reinforcing the base alloy system with nanoparticles using gas atomization
and subsequent laser powder bed fusion (LPBF) can counteract such material failure [6]. Hence, in
this work, titanium was added to Alloy 400 and atomized under nitrogen atmosphere in order to
cause TiN nanoparticle formation in the microstructure of printed components.",,,,,,
"['Sandoval, J. H.', 'Ochoa, L.', 'Hernandez, A.', 'Lozoya, O.', 'Soto, K. F.', 'Murr, L. E.', 'Wicker, R. B.']",2020-02-27T19:07:18Z,2020-02-27T19:07:18Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80091', 'http://dx.doi.org/10.26153/tsw/7112']",eng,2005 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,Nanotailoring Stereolithography Resins for Unique Applications using Carbon Nanotubes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc9390d8-74be-490a-ad26-b4f9f9b77606/download,,"Nanostructured materials and exploiting their properties in stereolithography (SL) may open
new markets for unique rapidly manufactured functional devices. Controlled amounts of multiwalled carbon nanotubes (MWCNTs) were successfully dispersed in SL epoxy-based resins and
complex three-dimensional (3D) parts were successfully fabricated by means of a multi-material
SL setup. The effect of the nanosized filler was evaluated using mechanical testing. Small
dispersions of MWCNTs resulted in significant effects on the physical properties of the
polymerized resin. A MWCNT concentration of .05 wt% (w/v) in DSM Somos® WaterShed™
11120 resin increased the ultimate tensile stress and fracture stress an average of 17% and 37%,
respectively. Electron microscopy was used to examine the morphology of the nanocomposite
and results showed affinity between the MWCNTs and SL resin and identified buckled
nanotubes that illustrated strong interfacial bonding. These improved physical properties may
provide opportunities for using nanocomposite SL resins in end-use applications. Varying types
and concentrations of nanomaterials can be used to tailor existing SL resins for particular
applications.",,,,,,
"['Roberts, Christopher E.', 'Ledbetter, Frank', 'Jones, Jennifer M.', 'Courtright, Zach', 'Blanchard, Alexander']",2024-03-26T23:14:06Z,2024-03-26T23:14:06Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124445', 'https://doi.org/10.26153/tsw/51053']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['NASA', 'in-space manufacturing', 'metal', 'additive manufacturing']",NASA Technology Maturation Plan for In-space Manufacturing of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a06d9e21-bc02-4c97-87b9-e0b073c9d1d8/download,University of Texas at Austin,"As the International Space Station’s (ISS) life approaches its end, NASA intends to travel
back to the Moon and establish a sustainable presence, paving a pathway towards Mars. A
fundamental shift in the current logistics strategy is required to support extended missions. Ondemand manufacturing enables reduced operational cost and increased long term sustainability
providing a pathway towards reducing NASA’s logistics burden. The In-Space Manufacturing
(ISM) portfolio at Marshall Space Flight Center is developing additive polymers, metals, and
electronics manufacturing technologies to enable a sustainable presence on the Moon and enable
long-duration transit missions. Manufacturing systems for in-space applications must meet a
unique set of constraints requiring a maturation path independent from processes targeted for
terrestrial use. In May 2023, the On Demand Manufacturing of Metals (ODMM) project, part of
the ISM portfolio funded through the Game Changing Development (GCD) program office, was
canceled; however, prior to cancelation, the engineering team developed a technology maturation
plan for in-space manufacturing of metallic components. The status of ODMM at closeout and an
overview of the technology maturation plan for ODMM are discussed.",,,,,,
"['Correa, D.M.', 'Klatt, T.D.', 'Cortes, S.A.', 'Haberman, M.R.', 'Kovar, D.', 'Seepersad, C.C.']",2021-10-13T20:55:34Z,2021-10-13T20:55:34Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88783', 'http://dx.doi.org/10.26153/tsw/15717']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['negative stiffness honeycomb', 'negative stiffness', 'external load', 'recoverable shock', 'laser sintering']",Negative Stiffness Honeycombs for Recoverable Shock Isolation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/41f305e1-0e30-4f72-b4c0-8e27a00e3e45/download,University of Texas at Austin,"Negative stiffness honeycomb materials are comprised of unit cells that exhibit negative
stiffness or snap-through-like behavior. Under an external load of small magnitude, a negative
stiffness honeycomb exhibits large effective elastic modulus, equivalent to those of other
standard honeycomb topologies. When the external load reaches a predetermined threshold, the
negative stiffness cells begin to transition from one buckled shape to another, thereby absorbing
mechanical energy and mechanically isolating the underlying structure. When the external load
is released, the honeycomb returns to its original topology in a fully recoverable way. In this
paper, theoretical and experimental behavior of negative stiffness honeycombs is explored, based
on FEA modeling and experimental evaluation of laser sintered specimens. Additive
manufacturing enables fabrication of these complex honeycombs in regular or conformal
patterns. Example applications are also discussed.",,,,,,
"Gervasi, Vito R.",2018-11-29T20:16:35Z,2018-11-29T20:16:35Z,1997,Mechanical Engineering,doi:10.15781/T28P5VW1T,http://hdl.handle.net/2152/70337,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SLA']",Net Shape Composites Using SLA Tetracast Patterns,Conference paper,https://repositories.lib.utexas.edu//bitstreams/448e9380-e38e-4e0b-8d5a-f8c2ada024ab/download,,"Net-shape composites have been a focus of
Solid Freeform Fabrication (SFF) for a number of
years. A new method to achieve net-shape
composites uses hollow Stereolithography (SLA)
TetraCast* patterns. The TetraCast* pattern is
injected with a filler material consisting of a matrix
(typically epoxy) and reinforcement fibers, flakes,
andlor particles. Upon solidification ofthe injected
matrix, the net-shape composite is achieved.
Net-shape composites are ideal for custom
manufacturing due to the virtually limitless
geometry capabilities of SLA. Areas such as
aerospace, medical, manufacturing, and others
could someday benefit from this process.
Research to date has shown this composite
structure to follow the ""rule ofmixtures."" It has
also been shown that heat-deflection, elasticmodulus,
and tensile-strength can be enhanced
andlor predicted in the composite material. Several
areas of continuing research include: viscosity
limitations, stair-step notch reduction,
reinforcement combinations, shrinkage prediction,
cooling methods, SLA skin removal, nextgeneration
TetraCast* structures, wear-resistant
coatings, process automation, and TetraCast*
pattern fill methods.",,,,,,
"['Klosterman, Don', 'Chartoff, Richard', 'Osborne, Nora', 'Graves, George', 'Lightman, Allan', 'Bezeredi, Akos']",2019-03-01T17:45:27Z,2019-03-01T17:45:27Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73522', 'http://dx.doi.org/10.26153/tsw/672']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'Lamination']",Net Shape Fabrication of SiC and SiC/SiC Components Using Laminated Object Manufacturing (LaM): Overall Process Flowchart,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ddfa736b-92a8-400d-a7da-e26ccf738687/download,,,,,,,,
"['Manzur, Tariq', 'Roychoudhuri, Chandra', 'Dua, Puneit', 'Hossain, Fahmida', 'Marcus, Harris']",2018-11-28T20:57:14Z,2018-11-28T20:57:14Z,1997,Mechanical Engineering,doi:10.15781/T2FF3MK37,http://hdl.handle.net/2152/70330,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['desk-top manufacturing', 'diode laser']",Net shape Functional Parts Using Diode Laser,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9569352-4731-412e-862e-44d2d9c396ea/download,,"Manufacturing processes, such as cutting, drilling, soldering, marking, forming 3Dsintered
parts from metal powders and laser vapor deposition, are now well established
practices using matured high power lasers like Nd:YAG, C02 and Excimer lasers(l).
These lasers are bulky, inefficient and expensive. Semiconductor diode lasers, if
wavelength is not a disadvantage, hold the potential of creating a major cost/convenience
breakthrough in these and other new manufacturing processes such as growing integrated
opto-electronics devices etc. They have the potential to initiate a mini industrial
revolution because they are compact, have high wall-plug efficiency (50%) and above all,
they can be mass produced (like computer chips). It is important to note that almost all
laser material processing can be carried out ifthe intensity available can cover the range
from 103 to 107 W/cm2
. Fortunately, microscopic as they may be, even low power diode
lasers emit reliably at 106 W/cm2
. The hurdle that needs to be solved is coupling energy
from a large number of diodes to obtain high total power without losing much oftheir
inherent brightness and yet keep the system cost low. Price of high power laser diodes
have already come down dramatically over the last five years; further reduction is
expected as the volume market keeps increasing rapidly. Current commercial devices are
mostly oftwo types: (1) fiber coupled arrays and (2) two-dimensional stacked arrays. We
are using both types. We believe, the ultimate high brightness and high total power at
low cost will be achieved by 2D array ofbroad area surface emitting lasers. We will
present the results of our various activities using 30W (980 nm, spot size - 600 ~m),
10 W (860 nm, spot size - 50 ~m) and 60 W (810 nm, spot size - 700 ~m) fiber-coupled
cw diode laser and 50 W (930 nm spot size -700 ~m) free space diode lasers on: (1)
fabricating 3D SLS parts directly from metal/ceramic powders using CAD/CAM design,
(2) laser assisted selective area vapor phase deposition of amorphous SiC and ShN4-rod,
(3) Pb and Ag soldering ofsimple electronic parts, (4) surface hardening ofstainless steel
ribbon.
INTRODUCT",,,,,,
"['Marin, Nena', 'Crawford, Richard H.']",2018-11-08T15:52:03Z,2018-11-08T15:52:03Z,1995,Mechanical Engineering,doi:10.15781/T2XW48G10,http://hdl.handle.net/2152/69895,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'CT', '3D CT reconstructions']",A Neural Network Architecture to Identify the Bone Tissue for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e2742f97-0b88-4ee0-b118-ba52c6de35e0/download,,"Computed tomography produces sets of tomograms for medical interpretation. Typical interpretation consists of imaging and simple observation on a 2D display screen, so that feature extraction and tissue differentiation is based primarily on human expertise. Solid freeform fabrication offers the promise of fabrication of prostheses based on actual patient anatomy. Use of CT data for this purpose requires automated interpretation. This paper presents a system architecture based on neural networks for the segmentation and classification of tissues of interest in tomograms. This approach produces a quantitative recovery of the available information by applying a feed-forward neural net trained with the back-propagation algorithm. The neural network architecture selected was tested on fabricated CT image matrices of the lower extremity.",,,,,,
"['Hayasi, Mohammad', 'Asiabanpour, Bahram']",2021-10-04T21:47:08Z,2021-10-04T21:47:08Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88359', 'http://dx.doi.org/10.26153/tsw/15298']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['adaptive slicing', 'design-by-feature', 'fully dense freeform fabrication', 'FDFF']",A New Adaptive Slicing Approach for the Fully Dense Freeform Fabrication (FDFF) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/500ca05a-2e82-4265-b1f1-de9b460a72ed/download,University of Texas at Austin,"FDFF is a process based on thin line cutting processes, variable thickness layering, slicing in
different orientations, and bulk layer attachment. The combination of these capabilities
enables the production of good quality complex parts from practically any material at a very
fast pace. As for rapid prototypes fabricated by the FDFF process, it is certainly possible to
employ adaptive slicing technique due to the possibility of cutting different metal/non-metal
sheet at various thicknesses. This paper proposes a new adaptive slicing method whereby the
capability of cutting a 3D solid model at the predefined sheets’ thicknesses is achieved and
the geometry of all internal and external features of a part is also investigated to ensure the
reduction of part geometry deviation through the seamless curvature detection. Despite most
previous works which start slicing a tessellated or direct CAD model at the maximum
available thickness, this system commences the process with available minimum thickness by
applying a new adaptive method to all pairs of contours at the top and bottom slices of the
layer. Autodesk Inventor solid modeler, as a design-by-feature solid modeler, is used for 3D
solid modeling. The proposed system is implemented by Visual Basic codes inside Inventor
using API functions to access both geometry and topology information of the design-by-feature solid model . This system has been successfully tested on a variety of complex parts
containing sophisticated internal and external features.",,,,,,
"['Darrah, James', 'Wielgus, Martin']",2018-04-10T18:59:09Z,2018-04-10T18:59:09Z,1990,Mechanical Engineering,doi:10.15781/T2XS5K066,http://hdl.handle.net/2152/64248,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'machine designer', 'DTM']",A New CAD Model Format For SFF Machines?,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5158e5eb-1da9-4a35-8453-cb5828597c76/download,,"This paper addresses the issue of a standard input data fonnat for Solid Freefonn Fabrication (SFF)
machines. Currently implemented approaches do not address the different aspects of Solid
Freefonn Fabrication. This paper will state the requirements from the perspective of the SFF
machine designer and make recommendations based on these requirements.",,,,,,
"['Asiabanpour, Bahram', 'Cano, Robert', 'VanWagner, Lane', 'McCormick, Thomas', 'Wasik, Farhana']",2020-02-20T20:08:42Z,2020-02-20T20:08:42Z,8/17/05,Mechanical Engineering,,https://hdl.handle.net/2152/80047,eng,2005 International Solid Freeform Fabrication Symposium,Open,"['Selective Inhibition of Sintering', 'Waste saving', 'Heater Design']",New Design for Conserving Polymer Powder for the SIS Rapid Prototyping Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/481b142f-c24f-4c7e-80da-243e38f74f33/download,,"Selective Inhibition of Sintering (SIS) is a Rapid Prototyping process that makes parts in a layerbased method by using polymer powders. Current SIS machines accomplish this layer-based
method by heating a fixed area of polymer powder. The current process is an area of concern
because the entire fixed area of each layer is cured, resulting in large amounts of polymer
powder being wasted. This paper explains the design of an automated, mechanical system that
will mask off areas of polymer powder with heat-resistant fingers, allowing for the adjustment of
the heated area in order to cure minimal amounts of polymer powder at each layer. Test results of
a prototype model showed significant reduction in polymer powder usage.",,,,,,
"['Thissell, W. Richards', 'Marcus, H.L.']",2018-10-03T16:42:26Z,2018-10-03T16:42:26Z,1994,Mechanical Engineering,doi:10.15781/T2ZS2KZ4Z,http://hdl.handle.net/2152/68662,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Selected area laser deposition', '3D printing', 'solid freeform fabrication']",New Developments in Processing and Control of Selected Area Laser Deposition of Carbon,Conference paper,https://repositories.lib.utexas.edu//bitstreams/353ad7e0-ab34-4444-8214-ef9728b9bcef/download,,"Selected area laser deposition (SALD) has been used to deposit carbon from methane, hydrogen,
oxygen, and argon mixtures using a third generation deposition system. The effect of two laser
scanning hardware/software designs on the development of morphological instability in the
resulting deposit is compared. One method uses programmed I/O using the main process control
CPU to calculate and download beam position and desired laser power. Another method is
presented which uses dedicated direct memory access (DMA) controllers and a dedicated
counter/timer to download the required information. Its improvements to the process include
better coordination between laser power and beam speed resulting in an improved beam power
delivery uniformity and an improved ability to utilize one CPU for control of more of the SALD
process variables.",,,,,,
"['Shuttleworth, M.P.', 'Esfahani, M.N.', 'Marques-Hueso, J.', 'Jones, T.D.A.', 'Ryspayeva, A.', 'Desmulliez, M.P.Y.', 'Harris, R.A.', 'Kay, R.W.']",2021-11-09T15:48:32Z,2021-11-09T15:48:32Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90101', 'http://dx.doi.org/10.26153/tsw/17022']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['co-fabrication', 'flex-rigid electronics', 'electronic circuitry', 'new manufacturing', 'additive manufacturing']",A New Digitally Driven Process for the Fabrication of Integrated Flex-Rigid Electronics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/111e94e0-5616-4a6e-bd2f-63865f64c855/download,University of Texas at Austin,"Conventionally, flexible and rigid electronics are produced separately using mask-based
lithography techniques thus requiring connectors to join circuits together introducing potential
failure modes and additional assembly. This work demonstrates a new manufacturing approach
which overcomes this limitation by allowing the co-fabrication of both flex and rigid electronic
circuitry within the same part. This is achieved by hybridizing polyetherimide fused filament
fabrication with selective photosynthesis of silver nanoparticles and copper electroless plating.
The performance and reliability of this approach has been experimentally validated via
manufacturing and testing positional sensors. By printing thin layers (< 50 µm), polyetherimide
exhibits a high flexibility with minimal degradation from fatigue. Where part thicknesses
exceed 180 µm, components start to exhibit rigid properties. A combination of various layer
thicknesses allows rigid-flex substrates to be produced, with secondary processing to deposit
the circuitry. Positional sensors with metalized feature sizes down to 300 µm have been
fabricated that when deflected demonstrate a repeatable 1.4 Ω resistance change for 43,500
cycles.",,,,,,
"['Zeng, Kai', 'Pal, Deepankar', 'Patil, Nachiket', 'Stucker, Brent']",2021-10-11T21:21:36Z,2021-10-11T21:21:36Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88647', 'http://dx.doi.org/10.26153/tsw/15581']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'temperature evolution', 'dynamic moving mesh method', 'mesh method', 'computational enhancements', 'fine-scale solution']",A New Dynamic Mesh Method Applied to the Simulation of Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9ff09d1-d590-4de0-932b-35a69af0bc6f/download,University of Texas at Austin,"The process of Selective Laser Melting (SLM) involves the moving of a laser beam across a
powder bed to melt material layer by layer. From the standpoint of modeling, this simple
procedure is complicated to capture accurately. SLM involves very high laser intensity values, on the
order of 1010 W/m2
 and a Heat Affected Zone (HAZ) that is orders of magnitude less than the
dimensions of the platform. Many computational models have been developed to study
temperature evolution in SLM, but most of these models only simulate a small part of the problem
with a fine mesh or the entire problem using a coarse mesh to avoid the computational burdens of
meshing the full problem with a fine mesh. In order to accurately capture the details of
temperature evolution anywhere in a full-sized part located anywhere in the build platform, in an
efficient manner, a new dynamic moving mesh method has been developed and implemented in
both ANSYS and in a unique Matlab code. This dynamic mesh has been shown to provide significant
computational enhancements over other solution methodologies, while enabling fine-scale
solutions anywhere in the domain space. A detailed comparison between various ways of solving
the SLM problem has been carried out to compare modeling approaches.",,,,,,
"['Qiu, Dan', 'Langrana, Noshir A.']",2019-09-23T16:47:15Z,2019-09-23T16:47:15Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75966', 'http://dx.doi.org/10.26153/tsw/3065']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Analysis,A New Feature in an Extrusion Based LM Process – Adaptive Roadwidth 399,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43332397-2b37-4985-bb9d-384eb06ba804/download,,"For extrusion based LM processes, a computational based adaptive roadwidth algorithm have been developed which further reduces (if not eliminate) all voids and defects. Toolpath equations are written in terms of roadwidth, vector path offset, subperimeter offset, and vector angles. The program computes all contours and vector paths to fill a layer, the location and size of all voids/defects, and makes comparison with the acceptable void limits. Based on this information, the adaptive roadwidth for the vector paths are then created to minimize the voids and defects. This new feature is added to the existing in-house multi-material LM CAD software.",,,,,,
"['Rodriguez, Nicholas', 'Crawford, Richard']",2021-11-08T23:04:14Z,2021-11-08T23:04:14Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90070', 'http://dx.doi.org/10.26153/tsw/16991']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printed parts', 'high strength', 'ductile', 'filament deposition', 'fused deposition modeling', '3D printer', '3D printing']","New Filament Deposition Technique for High Strength, Ductile 3D Printed Parts",Conference paper,https://repositories.lib.utexas.edu//bitstreams/649ba7ff-0635-41a6-a852-8dcaa0e0b8b8/download,University of Texas at Austin,"This paper proposes a method to use an off-the-shelf commercial Fused Deposition
Modeling (FDM) 3D printer with minimal modifications to manufacture higher strength parts
that fail in a ductile rather than brittle manner. A novel scan pattern designed to increase interlayer adhesion in FDM parts is modeled and tested to determine its effect on mechanical
properties of printed ABS parts. Results from three-point bend testing indicate a significant
increase in part strength and elongation at break when using the proposed scan pattern compared
to parts manufactured using a traditional scan pattern.",,,,,,
"['Patil, Nachiket', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-11T21:18:32Z,2021-10-11T21:18:32Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88645', 'http://dx.doi.org/10.26153/tsw/15579']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Selective Laser Melting', 'powder bed fusion', 'dimensional reduction', 'phenomenological multi-scale simulation', 'finite element analysis', 'Eigen modes', 'mask projection']",A New Finite Element Solver using Numerical Eigen Modes for Fast Simulation of Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c00a3ed-cd95-4e47-891a-773d6bf51d9a/download,University of Texas at Austin,"A new efficient numerical technique has been formulated for dimensional reduction and phenomenological
multi-scale simulation of additive manufacturing processes using finite element analysis. This technique is
demonstrated using prismatic build volumes to represent the Selective Laser Melting powder bed fusion additive
manufacturing process. The Eigen modes determined as an outcome of implementation of this technique will
help to reduce the time necessary for optimization of process parameters and closed loop control. In addition to
thermal simulations of the Selective Laser Melting process, this technique is also applicable to the simulation of
lattice structures, layered materials such as ultrasonically consolidated laminates, thin walled coatings and
development of high fidelity beam and plate theories for parts made using additive manufacturing processes. A
future integration of this method with analytical Eigen wavelets will provide infinite support compared to finite
support provided by directional polynomial shape functions currently used for implementation of finite element
strategies. The present Eigen modes will be also useful in analysis and optimization of mask projection based
additive manufacturing processes.",,,,,,
"['Yen, H. C.', 'Chiu, M. L.', 'Huang, P. H.']",2020-03-11T15:23:01Z,2020-03-11T15:23:01Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80250', 'http://dx.doi.org/10.26153/tsw/7269']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Ceramic Laser Fusion,A New Layer Casting System for Ceramic Laser Rapid Prototyping Apparatus,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a794e0d-f107-4043-9e66-7b0ad99e1794/download,,"In the existing Ceramic Laser Fusion system, slurry is fed on the high
temperature surface of the green part; therefore, a part of water infiltrates into the
green block and vaporizes before the process of layer casting. As a result, the slurry
viscosity rises gradually; the quality of the layer surface is not uniform, and the green
part density is uneven. The aim of present study is to develop a new layer casting
system which can solve the problems mentioned above to obtain a green part with
uniform surface quality and density, and to shorten the time-taken of part fabrication.
The first part of the paper illustrates the major requirements and parameters of a slurry
distributor; the second part describes the integration of the slurry feeding device and
layer casting system. The integrated system can feed slurry and cast thin layer
simultaneously; consequently, the drawbacks of the existing system can be eliminated
and the time-taken of the layer casting can be shortened. A variable-frequency drive
(inverter) is used to control the motor speed. The relation between the frequency and
the slurry delivery can be included in the process control program to adjust the
quantity in accordance with the layer thickness; hence, the waste of the slurry can be
reduced.",,,,,,
"['Marchelli, Grant', 'Ganter, Mark', 'Storti, Duane']",2021-09-29T14:37:23Z,2021-09-29T14:37:23Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88183', 'http://dx.doi.org/10.26153/tsw/15124']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'new material/binder systems', 'mid-fire to high-fire ceramics']",New Material Systems for 3D Ceramic Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1097313-9be8-4530-bf71-e880560e2a3d/download,University of Texas at Austin,"We present new material/binder systems for use in 3D printing hardware for the creation
of mid-fire to high-fire ceramics. 3D printing is one of a variety of techniques in which objects
are produced by printing binder onto a layer of powder. A brief overview of our process is
presented and demonstration works are shown. Several available dry clay bodies were adapted
for use in an existing, commercial 3D printer. Details of powder formulation are presented.
Experimental results are presented for strain, flexural stress, and porosity for the various clay
bodies as a function of firing temperature.",,,,,,
"['Keller, Nils', 'Ploshikhin, Vasily']",2021-10-18T22:09:34Z,2021-10-18T22:09:34Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89269,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'residual stress', 'residual distortion', 'manufacturing predictions', 'mechanical layer equivalent']",New Method for Fast Predictions on Residual Stress and Distortion of AM Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/64482aa9-945e-4037-a164-afa6c958eb0f/download,University of Texas at Austin,"A new multi-scale approach based on the method of finite elements is developed in
order to enable much faster predictions of residual stress and distortion for AM parts. The
approach includes the calibration of the heat source, the analysis of scanning strategies, the
generation of the so-called “mechanical layer equivalent” (MLE) and its integration into a fast
structural analysis. The use of MLE determined on the micro-scale and mapped into the largescale structural analysis reduces computational time in comparison with the conventional
thermo-mechanical simulations from months to hours while saving the same accuracy of
numerical predictions. The new method is realized in newly developed powerful AM
software. Simulation results are in a very good agreement with experimental measurements of
distortion and residual stress. The potential of the new method to compensate the expected
distortion using pre-deformation of parts is demonstrated by numerical experiments of a near-net-shape AM fabrication.",,,,,,
"['Khodabakhshi, K.', 'Gilbert, M.', 'Dickens, P.', 'Hague, R.', 'Fathi, S.']",2021-09-29T14:47:02Z,2021-09-29T14:47:02Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88186', 'http://dx.doi.org/10.26153/tsw/15127']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['polymerization mixture formulation', 'jetting process', 'polyamide 6 parts']",New polymerization-mixture formulation for jetting: An approach to production of polyamide 6 parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cd0b3f22-ebf7-49ff-a851-3cc3e78a453d/download,University of Texas at Austin,"Poor mechanical properties of manufactured parts is one of the main problems in most
of the RP and RM processes. This work deals with a study on formulation of new
polymerization mixtures with the aim of being used in jetting process. Two different
catalyst components were compared in order to shorten the solidification time and
improve the final properties of the manufactured part. The feasibility of jetting
polymerization mixtures at jetting head temperature was also investigated. Different
characterization and visualization methods (i.e. such as DSC, viscometry, TGA, and
hot stage optical microscopy) were used to monitor the polymerization progress and
manufactured part properties.",,,,,,
"['Uhlmann, E.', 'Elsner, P.']",2020-02-20T20:30:33Z,2020-02-20T20:30:33Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80050,eng,2005 International Solid Freeform Fabrication Symposium,Open,polymer applications,New Printing Technology for Fully Graduated Material Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/263268b9-ec44-423c-b472-96aaa0ebcf30/download,,,,,,,,
"['Cevolini, Franco', 'Davis, Stewart', 'Rinland, Sergio']",2021-09-23T22:40:14Z,2021-09-23T22:40:14Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88042', 'http://dx.doi.org/10.26153/tsw/14983']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['CRP Rapid Casting Method', 'competitive motor sports', 'Epsilon Euskadi eel']",New Rapid Casting Techniques for Competitive Motor Sports,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5cdfe931-3481-4ceb-a923-56a3e98b3285/download,,"Casting components utilizing free form manufacturing techniques to produce investment
patterns have in recent years been overshadowed by the promise of Direct Metal machines.
Despite this casting vendors continue to work diligently to make the creation of extremely
complex components as an almost common place occurrence. This paper examines the work
of CRP Technology and its creation of Windform® PS to advance casting techniques and
ultimately produce front and rear uprights for the new “Epsilon Euskadi ee1” for competition
in American Le Mans Series and 24 hours of Le Mans 2008. Developed and manufactured
utilizing the “CRP Rapid Casting Method” these Titanium Rapid Castings highlight the hard
and complex work involved in making this extremely difficult task look easy. The process is
examined and outlined to help others understand the work involved.",,,,,,
"['Ventura, Susanna C.', 'Narang, Subhash C.', 'Sharma, Sunity', 'Stotts, John', 'Liu, Chunling', 'Liu, Susan', 'Ho, Lung-Hua', 'Annavajjula, Durga', 'Lombardo, Steven J.', 'Hardy, Anne', 'Mangaudis, Mike', 'Chen, Eric', 'Groseclose, Lance']",2018-11-14T17:52:46Z,2018-11-14T17:52:46Z,1996,Mechanical Engineering,doi:10.15781/T2G15TX0P,http://hdl.handle.net/2152/70252,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD/CAM', 'SFF', 'UV curable polymers']",A New SFF Process for Functional Ceramic Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6fe955ac-d7cd-48fc-bfd8-23823a2ce6ed/download,,"SRI International in collaboration with Saint-Gobain/Norton Industrial Ceramics
Corporation and Allison Engine Company is developing a new SFF process, Direct Photo
Shaping, for the fabrication of functional ceramic components. The process is based on the layerby-layer
photocuring of ceramic slurries containing monomers curable by visible light. Each layer
is photoimaged by a liquid crystal display (LCD) or a digital light processing (DLP) projection
system. After binder removal and sintering, the properties of silicon nitride tiles prepared according
to the Dire~t Photo Shaping process were found to be comparable to properties of tiles formed by
conventional methods.",,,,,,
"['Rock, Stephen J.', 'Gilman, Charles R.']",2018-10-04T20:02:13Z,2018-10-04T20:02:13Z,1995,Mechanical Engineering,doi:10.15781/T2WM14C85,http://hdl.handle.net/2152/68709,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['freeform powder molding', 'SFF', 'prototyping methods']",A New SFF Process for Functional Part Rapid Prototyping and Manufacturing: Freeform Powder Molding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b5399f8-388c-4ccf-8523-088f4beeeada/download,,"Freeform Powder Molding l (FPM), a new Solid Freeform Fabrication process capable of
directly producing functional parts from a wide range of structural materials, is presently being
developed. This paper describes the fundamental process concept currently pending patent and
provides early results demonstrating process feasibility. Materials used in process validation
experiments include copper, iron, nickel, 304 stainless steel, and titanium. The process has the
potential to meet the needs of both Rapid Prototyping and small lot-size manufacturing
applications.",,,,,,
"['Wang, Feng', 'Chen, Ke-Zhang', 'Feng, Xin-An']",2020-02-13T19:54:53Z,2020-02-13T19:54:53Z,8/24/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79971', 'http://dx.doi.org/10.26153/tsw/6996']",eng,2004 International Solid Freeform Fabrication Symposium,Open,composite materials,Novel Implementations of Plasma Spraying for Fabricating Components Made of a Multiphase Perfect Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c8946b11-d459-4135-98da-33d5875c9876/download,,"A component, which has a perfect combination of different materials (including homogeneous
materials and different types of heterogeneous materials) in its different portions for a specific
application, is considered as the component made of a multiphase perfect material. Based on
the requirements for fabricating different types of heterogeneous materials, a hybrid
manufacturing process with layered manufacturing, micro-fabrication, and mechanical
machining has been developed under the guidance of Axiomatic Design. According to the
hybrid process, this paper investigates the related technologies and selects plasma spraying
technology to spread materials layer by layer; and further analyzes its key design parameters,
improves plasma spraying technology, and presents a novel implementation of this
technology.",,,,,,
"['Slightam, Jonathon E.', 'Gervasi, Vito R.']",2021-10-05T18:45:05Z,2021-10-05T18:45:05Z,8/18/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88404', 'http://dx.doi.org/10.26153/tsw/15343']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'fluid power components/systems', 'solid state actuators', 'solid state actuator systems', 'Milwaukee School of Engineering']",Novel Integrated Fluid-Power Actuators for Functional End-Use Components and Systems via Selective Laser Sintering Nylon 12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fda4555e-729d-481a-9994-b6aaf627c052/download,University of Texas at Austin,"The Milwaukee School of Engineering (MSOE) and the Additive Manufacturing (AM)
community have an interest in expanding applications of AM and broadening market
opportunities. Specific areas of interest include robotics and fully functional
components/systems. MSOE has developed methods for streamlining the development and
implementation of functional fluid power components/systems, such as Magnetic Resonance
Imaging (fMRI) robotic surgery systems, rescue robotics, and customized form-fit orthotic and
prosthetic devices, all of which have a high power-density and high efficiency with the use of
fluid power. MSOE has defined several of these components and devices as solid state actuators
(SSA) (single, multi-functional components made of diaphragms, bellows, springs etc.) or solid
state actuator systems (SSAS). Prior work has already been done on integrated systems for
robotic prototypes to help determine and improve workspaces, thus allowing designers to make
practical design changes at a low cost. Implementing AM fluid power devices in industry has
also been done, where applications largely include human-machine interaction and biomimetic or
continuum robotics. However, most devices are made up of numerous components in assemblies.
MSOE has made it possible for mechanisms to be fully functional as built and as a single entity.
The implementation and development of SSAs and SSASs are discussed along with practical
design considerations of integrated functional fluid power components.",,,,,,
"['Wang, Z.', 'Zhang, Y.', 'Bernard, A.']",2021-12-06T23:33:18Z,2021-12-06T23:33:18Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90718', 'http://dx.doi.org/10.26153/tsw/17637']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['tool-path', 'constructuve design', 'triply periodic minimal surface', 'knowledge-based system']",A Novel Knowledge-Based Toolpath Constructive Approach for Designing High-Precision Graded Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/662eb205-3ecd-4e08-9b27-836ee615f2d2/download,University of Texas at Austin,"Current part-scale lattice design methods cause accuracy loss and manufacturability uncertainty in
AM preparation stages. STL model conversion and slicing can lead to loss of shape accuracy and
surface quality, while unqualified toolpaths may cause printing failures, e.g. pores or re-melting in
the powder-bed fusion process. Moreover, all these steps are time-consuming due to the large
model file. To solve these challenges, this paper proposes a novel knowledge-based toolpath constructive design method to generate high-precision graded lattice unit cells with manufacturability.
It integrates implicit modeling, variable distance field, direct slicing and fine toolpath configuration
to construct qualified toolpaths without any intermediate steps. To save computation time in part-scale lattice design, predefined different types or sizes of graded lattice unit cells are populated and
assembled into a given design space directly. Hence, it has big potential to improve industrial application of part-scale porous structures with fine and gradient porous features.",,,,,,
"['Pogue, Robert T.', 'Chartoff, Richard P.']",2018-12-05T16:46:02Z,2018-12-05T16:46:02Z,1997,Mechanical Engineering,doi:10.15781/T26970J2T,http://hdl.handle.net/2152/71397,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['spectroscopy', 'stereolithography']",Novel Liquid Crystal Monomers for Stereolithography: Reaction Rates and Photopolymerization Conversion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/37cfe08d-877d-49ff-9f62-bd4ac8e01d9e/download,,"Liquid crystal (LC) monomers are a novel type ofresin for stereolithography that result
in polymers having unique physical and mechanical properties. These monomers consist ofrigid
central cores connected to acrylate functional groups by short aliphatic chains. Because ofthe
rigid-rod structure ofthe monomer the cross-linked polymer networks formed have high glass
transition temperatures (Tg). The high TglS result in particularly high upper-use temperatures for
stereolithography parts.
This paper reports on photopolymerization reaction rates and monomer conversion for
two acrylate monomers measured using reflectance real-time infra-red spectroscopy (RRTIR).
The RRTIR method measures the disappearance ofreactive acrylate groups in the monomer as a
function oftime while the monomers are being exposed to UV light. For the two new resins, UV
irradiation using an argon ion laser gives rapid photopolymerization with acrylate conversion as
high as 95 %. Conversion and polymerization rates in these monomers are dependent upon
photo-initiator selection and concentration. In addition, the results indicate that conversion
increases with increased laser intensity and elevated temperatures.",,,,,,
"['Schultz, J. W.', 'Ullett, J. S.', 'Chartoff, R. P.', 'Pogue, R.T.']",2018-12-05T16:44:20Z,2018-12-05T16:44:20Z,1997,Mechanical Engineering,doi:10.15781/T2B27QB6K,http://hdl.handle.net/2152/71396,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'Liquid crystal']",Novel Liquid Crystal Resins for Stereolithography: Mechanical and Physical Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e43de412-60d6-4b2e-bf58-a4a9a45d6616/download,,"This paper considers photocurable liquid crystal (LC) monomers which are a new class of
stereolithography resins. These resins form polymers with high upper-use temperatures. The rodlike
molecules can be aligned by an external force. When cured in an aligned state, the aligned
structure is ""locked in"" resulting in materials with anisotropic physical and mechanical
properties. FTIR spectroscopy, thermo-mechanical analysis (TMA), dynamic mechanical analysis
(DMA), and large strain mechanical tests were applied to liquid crystal photo-polymers, both in
the green state and after postcure. These measurements showed that the photo-polymerization
reaction locked in the molecular order. Elastic modulus in the glassy state, revealed
approximately a factor of two difference between the directions parallel and perpendicular to the
alignment. Thermal expansion measurements showed an anisotropic linear expansion that was
very small, and sometimes negative in the alignment direction. Finally, these resins demonstrated
high glass transition temperatures which could be advanced to as high as 150°C by postcuring.",,,,,,
"['Erler, M.', 'Streek, A.', 'Schulze, C.', 'Exner, H.']",2021-10-12T19:52:33Z,2021-10-12T19:52:33Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88726', 'http://dx.doi.org/10.26153/tsw/15660']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser micro sintering', 'micro powder', '3D-measurement', 'in-situ']",Novel Machine and Measurement Concept for Micro Machining by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f37ae447-91a0-43d4-a417-ef553a653ed8/download,University of Texas at Austin,"Laser sintering has been established in solid freeform fabrication to produce individual
micro parts and small batches. However, the achievable resolution and accuracy of this
technology seems to be not sufficient to meet prospective demands in micro production, i.e.
micro system technology, aerospace or innovative medical applications. As a modification of
the technology, laser micro sintering (LMS) was developed to overcome this limitation. In
general, the results obtained in LMS demonstrated already the high potential of this additive
manufacturing process in micro production. The limited dimensions of the micro parts and
even the reproducibility, due to the special process requirements regarding the applied powder
particles sizes in the µm-ranges, inhibits the implementation as an industrial manufacturing
process. Therefore a novel concept of setups, suitable for an industrial demand of selective
laser sintering with noticeable higher resolutions has to be proven. As a first, a novel
machinery setup for a high resolution selective laser sintering has been studied in this work.
To achieve a sufficient repeatability of the sintering process, a new method for in-situ
analyzing and measuring is implemented and allows the verification the homogeneity and
thickness first: of the deposited powder layers and second: of the resulting sinter structure. As
an innovative feature the measurement system has to be applied as an in-situ method for
direct process controlling in a future use. Accordingly, the possibility to recognize structural
defects during generation of sintered bodies are presented and comparably analyzed by cross
sections of the respective specimens.",,,,,,
"['Xie, Yang', 'Zhang, Haiou', 'Wang, Guilan', 'Zhou, Fei']",2021-10-12T21:28:00Z,2021-10-12T21:28:00Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88744', 'http://dx.doi.org/10.26153/tsw/15678']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['metamorphic rolling mechanism', 'variable wall thickness', 'arc based deposition', 'additive manufacturing', 'net shape components']",A Novel Metamorphic Mechanism for Efficient Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/196d5e8c-d94f-4353-973c-0d04ed9bede4/download,University of Texas at Austin,"A novel metamorphic rolling mechanism (MRM) based on genetic evolution
synthesis that realized multiway, multiple-DOF and synchronous plastic forming in arc
based deposition processing of components with variable wall thickness is proposed
in this paper. Topology and mechanical structure of the metamorphic mechanism is
presented and D-H equation is derived. Experiments show that firstly efficient
manufacturing of components with variable wall thickness can be realized by
synchronous rolling in vertical direction. Secondly precision and surface
configurations of the components are improved compared with that of freeform
deposition manufacturing. The metamorphic mechanism provides possibilities of
efficient hybrid manufacturing of near net shape components with variable wall
thickness.",,,,,,
"['Goel, Abhishek', 'Surana, Anupam', 'Choudhury, Asimava Roy']",2021-09-23T21:46:00Z,2021-09-23T21:46:00Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88029', 'http://dx.doi.org/10.26153/tsw/14970']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['part decomposition', 'Hybrid Rapid Prototyping', 'undercut edges']",A Novel Method for Part Decomposition Based on Undercut Edges for Efficient Hybrid Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f216e32-b810-4bf7-9665-8ed091965597/download,,"Layered Manufacturing allows physical prototypes of 3D parts to be built directly from their 
computer models, as a stack of 2D layers. This article proposes to decompose the model to be 
built into minimum number of layers and then build each layer separately by performing 
machining operations on a given sheet of metal, using a 3-axis CNC milling machine and 
adhering the layers, allowing large models to be built in parallel. The decomposition of the 
model is carried out in such a fashion that it decomposes all the inaccessible regions in the object 
such as under-cut concave edges. For a given build up direction, the undercut edges, which cause 
a part to be inaccessible by a tool, are extracted and eliminated in two decomposition steps 
ensuring that the number of layers are as least as possible, thus minimizing the build time.",,,,,,
"['Li, Jinghao', 'Luo, Zhibo', 'Guan, Xiaoyi', 'Zhou, Xianglin', 'Brochu, Mathieu', 'Zhao, Yaoyao Fiona']",2021-11-11T16:43:17Z,2021-11-11T16:43:17Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90243', 'http://dx.doi.org/10.26153/tsw/17164']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['microstructure simulation model', 'microstructure', 'invasion model', 'grain growth', 'direct energy deposition', 'DED']",A Novel Microstructure Simulation Model for Direct Energy Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0ab1186-c1fa-4ecb-9d2e-ef82582913e3/download,University of Texas at Austin,"The microstructure of additive manufacturing parts has unique characteristics. In this
paper, a novel microstructure simulation model is proposed in grain level, called
""Invasion Model"", to simulate the transient competitive grain growth behaviour in
direct energy deposition (DED) process. Different from the phase field method, the
invasion model does not focus on the exact dendrite geometry immersed in the liquid
phase which will usually lead into high computational cost. The key point of the
invasion model is its capability to reflect the transient competitive grain growth
behavior under the triensent thermal gradient located at the bottom of the melt pool. An
‘invasion factor' is proposed to represent the possibility that one single crystal will
invade its adjacent crystals in each time step. This ‘invasion factor' is calculated by the
relation between crystallographic orientation and a changing thermal gradient under the
help of the grain boundary criterions in competitive grain growth. Furthermore, the
shape and the cooling condition of the melt pool are vital to the final microstructure.
The geometry of the melt pool is extracted from the temperature history data of finite
element and CFD simulation. The melt pool geometry is analyzed quantitively from
interpolated temperature history data and inputted into the invasion model. A vertical
cross section of DED fabricated Ti-6Al-4V in multiple layers was investigated by the
invasion model, and the competitive grain growth behavior is simulated between the
crystals with random crystallographic orientations.",,,,,,
"['Pan, Yayue', 'Patil, Abhishek', 'Zhou, Chi']",2021-10-19T15:44:01Z,2021-10-19T15:44:01Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89304,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['multi-material printing', 'metal-polymer composite', 'additive manufacturing', 'electrophotography', 'stereolithography', 'vat photopolymerization']",A Novel Projection Based Electro-Stereolithography (PES) Process for Composite Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0a01ca5-8a77-4cfd-b179-21682cd3c41f/download,University of Texas at Austin,"Most current additive manufacturing processes can only process one material in one build.
Few of them are able to fabricate multiple materials and composites, with limited choices of
materials. In this research, we propose a novel Projection based Electro-Stereolithography (PES)
process, which is able to fabricate composites with high resolution and fast speed, and a big
range of material choices. The proposed novel additive manufacturing process integrates
projection-based stereolithography and electrophotography approaches by using a
photoconductive film and digital micro-mirror device (DMD). In PES, a photoconductive film is
used to collect charged particles in the regions illuminated by light. More specifically, a laser
beam is scanning on the film to create a latent image on the film and then a layer of charged
particles is attracted to the illuminated area. A liquid bridge system and a stamping system have
been developed to transfer particles from the film to liquid resin precisely. Furthermore, a digital
mask is used to pattern the light irradiation of the DMD chip to selectively cure the
photopolymer liquid resin and particles of that layer. By transferring particles with designed
patterns to the resin in a projection based stereolithography system, we will be able to fabricate
composites with various materials at microscopic resolutions very quickly. Challenges in this
novel manufacturing process, including transferring of particles and curing control, have been
discussed and addressed. The corresponding key parameters of the particles collecting, dropping
and curing in the PES system have been identified. A proof-of-concept PES testbed has been
developed and a couple of tests have been performed to validate the feasibility of the proposed
additive manufacturing approach.",,,,,,
"['Biester, K.', 'Schwarz, N.', 'Hermsdorf, J.', 'Kaierle, S.']",2024-03-26T16:42:24Z,2024-03-26T16:42:24Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124366', 'https://doi.org/10.26153/tsw/50974']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['LDNA', 'cladding', 'waviness', 'welding strategy', 'high deposition rate']",NOVEL WELDING STRATEGY IN HIGH DEPOSITION RATE LASER-ASSISTED DOUBLE-WIRE WELDING PROCESS WITH NONTRANSFERRED ARC,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e32f634-0a8f-444d-a5bb-4c4251f28751/download,University of Texas at Austin,"Laser-assisted double wire welding with nontransferred arc melts material using an arc
between two conveyed wires. Driven by gravity the molten metal drops onto the substrate. A laser
beam is oscillated on the melt pool to bond the weld beads to the substrate without undercuts.
Claddings at high deposition rates (11.6 kg/h) were performed with 316L on mild steel. The first
welding strategy (AAA) is to weld adjacent beads (A) with a varied track spacing of 7 to 9 mm.
The second strategy (ABA) consists of beads (A) welded at a distance of 14 to 18 mm from each
other, so that a third bead (B) can be deposited in the space between. Claddings with the determined
track spacing for AAA of 9 mm and ABA 18 mm were created in order to compare the resulting
surface properties. The ABA cladding did not achieve a more uniform surface and less waviness
than the AAA cladding.",,,,,,
"['Liu, Heng', 'Sparks, Todd E.', 'Liou, Frank W.', 'Dietrich, David M.']",2021-10-11T21:29:06Z,2021-10-11T21:29:06Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88649', 'http://dx.doi.org/10.26153/tsw/15583']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['direct metal deposition', 'thermo-mechanical finite element model', 'finite element model', 'residual stress', 'deformation', 'deposition parameters']",Numerical Analysis of Thermal Stress and Deformation in Multi-Layer Laser Metal Deposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b172e910-7708-4f7a-bb16-3ce46c3beed3/download,University of Texas at Austin,"Direct metal deposition (DMD) has gained increasing attention in the area of rapid manufacturing and repairing. This process involves extremely high thermal gradients and heat and
cooling rate, resulting in residual stresses and distortion. This paper presents a 3D sequentially
coupled thermo-mechanical finite element model to predict residual stresses and deformations.
The temperature distribution, thermal stress field and geometry deformation across domain are
illustrated. The effect of deposition parameters on residual stress and deflections are also explored. A set of validation experiments for mechanical effects were conducted using laser
displacement sensor. The comparisons between the simulated and experimental results show
good agreement.",,,,,,
"['Thakar, Yogesh', 'Pan, Heng', 'Liou, Frank']",2020-02-14T16:21:38Z,2020-02-14T16:21:38Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79992', 'http://dx.doi.org/10.26153/tsw/7017']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Axial powder stream,Numerical and Experimental Analysis of the Powder Flow Streams in the Laser Aided Material Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c57f489a-066f-4409-aa03-94a1a7aae86a/download,,"Axial powder stream concentration between the nozzle end and the deposition point is an
important process parameter in the laser aided material deposition process. The powder
concentration is greatly influenced by the nozzle geometry in use. This paper describes the
numerical and experimental analysis of this important parameter in relation to the coaxial nozzle.
The experiments are performed with the different nozzle geometries to generate various flow
patterns of the gravity fed powder in a cold stream. The results of the experimental analysis are
compared with the numerical simulation and found justified. These results are used in concluding
the significance of important nozzle parameters for various powder concentration modes.",,,,,,
"['du Plessis, Anton', 'Yadroitsava, Ina', 'Kouprianoff, Dean', 'Yadroitsev, Igor']",2021-11-09T20:28:43Z,2021-11-09T20:28:43Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90158', 'http://dx.doi.org/10.26153/tsw/17079']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['lattice structure', 'porosity', 'Ti6Al4V', 'laser based powder bed fusion', 'microCT']",Numerical and Experimental Study on the Effect of Artificial Porosity in a Lattice Structure Manufactured by Laser Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/57f1888f-9634-471d-a86c-06a461808236/download,University of Texas at Austin,"Additively manufactured lattice structures are used in various applications due to their
unique properties, especially low weight with relatively good strength and stiffness. While lattices
have been investigated widely, the effect of manufacturing flaws on the lattice performance was
not yet analyzed in detail. One important type of manufacturing flaw which can be relatively easily
analyzed numerically and experimentally is unwanted voids or porosity. In this work, using a
simple cubic lattice structure as a test case, pores with varying sizes were induced in a single strut
and compressive loading simulated. Ti6Al4V ELI (extra low interstitial) lattices produced by laser
powder bed fusion, with and without induced pores, were subjected to mechanical compression
tests. MicroCT images validated the presence and size of the induced voids in produced samples.
The mechanical compression results show that even relatively large pores in individual loadbearing struts do not affect the ultimate compressive strength of these lattices, for these particular
lattice shapes studied and for individual large pores.",,,,,,
"['He, Haiyang', 'Cheng, Bo', 'Schmidt, Kaja', 'Kruse, Claudia', 'Tuffile, Charles']",2021-11-18T17:24:30Z,2021-11-18T17:24:30Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90436', 'http://dx.doi.org/10.26153/tsw/17357']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['polymer dispensing', 'computational fluid dynamics', 'CFD', 'strand', 'process-quality map']",Numerical Investigation of Extrusion-Based Additive Manufacturing for Process Parameter Planning in a Polymer Dispensing System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b94a66b-65cc-4bb0-863d-7aecfff682e5/download,University of Texas at Austin,"This paper establishes a computational fluid dynamics (CFD) model using ANSYS Fluent
for the time-pressure polymer dispensing process. The developed model simulates the process of
liquid being applied on a substrate and predicts critical performance indexes, such as strand width
and height, of the dispensing system. A mesh sensitivity analysis has been performed to identify
the element size for achieving satisfactory accuracy and efficient computation time. The influences
of material properties, such as surface tension and viscosity, on the simulation results were
investigated. In addition, the effect of flow rate and nozzle translational speed on strand width
were studied. The simulation results were validated against experimental measurements, and the
model was demonstrated to be effective in predicting the strand width. Based on the simulations,
a process map was constructed for process parameter planning and optimization.",,,,,,
"['Li, Xuxiao', 'Tan, Wenda']",2021-10-26T18:23:19Z,2021-10-26T18:23:19Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89551,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'laser absorption', 'powder bed', 'ray tracing method']",Numerical Investigation of Laser Absorption by Metal Powder Bed in Selective Laser Sintering Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08982495-5c5f-49b8-80ee-0dfcbcfa1d54/download,University of Texas at Austin,"Laser absorption by powder bed in selective laser sintering (SLS) processes remains a
critical issue to be fully understood. This issue is important for the appropriate selection of
processing parameters in practices as well as an accurate definition of the thermal input in
numerical modeling. In this work, a ray tracing model is used to study this issue. In parametric
studies, the effects of laser parameters and powder bed structures on the laser absorption are
investigated. It is found that a top-hat laser produces a more uniform laser absorption within laser
heated spots than a Gaussian laser. The absorption distribution generally does not follow an
exponential decay; instead, it gradually increases to a “peak” and then decreases along the laser
shooting direction. The absorption near the substrate can be enhanced when the powder bed
thickness is reduced, which helps to bind the newly deposited layer with its substrate in SLS
processes. Finally, using bimodal powder beds can reduce laser penetration and produce more
uniform laser absorption in laser heated spots.",,,,,,
"['Sheth, Sanchita', 'Taylor, Robert M.']",2021-11-03T20:57:25Z,2021-11-03T20:57:25Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89932,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['stiffness', 'raster orientation', 'fused deposition modeling', 'numerical investigation']",Numerical Investigation of Stiffness Properties of FDM Parts as a Function of Raster Orientation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4dfff7ad-f97c-4274-b330-806521302439/download,University of Texas at Austin,"This work discusses a numerical investigation of stiffness properties of parts printed
using Fused Deposition Modeling (FDM). Small volumes of different raster orientations
were modelled and meshed using SIMULIATM (Abaqus). These meshes were exported to a
damage prediction software BSAM, which uses a homogenization approach to model
interface bond strength between adjacent raster beads. In BSAM, boundary conditions,
connectivity and material properties have been specified. This BSAM model was then used
to compare stiffness properties at various raster angles. A similar trend in the modulus
values was observed from experimental test data. Further this model could be used to specify
and predict interface properties for the specimens at various raster angles which could be
used to eventually predict strength and fracture.",,,,,,
"['Jamshidinia, M.', 'Kong, F.', 'Kovacevic, R.']",2021-10-11T22:48:35Z,2021-10-11T22:48:35Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88674', 'http://dx.doi.org/10.26153/tsw/15608']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['fatigue failure', 'surface roughness', 'fatigue strength factor', 'bio-compatible dental implant', 'Electron Beam Melting® (EBM)']",The Numerical Modeling of Fatigue Properties of a Bio-compatible Dental Implant Produced by Electron Beam Melting® (EBM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/2568c0bb-6d09-4d1d-b020-c399a3dc61b7/download,University of Texas at Austin,"Cyclic load could result in the fatigue failure of a component at stress levels below the
yielding stress of material. Therefore, studying the mechanical behaviors of a dental implant
structure under cyclic load is required. The numerical modeling of a cyclic load test was
performed for a bio-compatible dental implant by using ANSYS® Workbench®. The fatigue test
samples, made of Ti-6Al-4V were manufactured by Electron Beam Melting® (EBM) process.
An abutment with octahedral lattice structure of 2 mm unit cell size was selected to design the
abutment. A sinusoidal wave was used to apply the cyclic load, where the loading ratio was set at
10%. The influences of the loading force and the fatigue strength factor on the fatigue life of the
octahedral lattice structure were numerically studied. According to the results, an increase in the
loading force was associated with an increase in the maximum equivalent stress developed in the
lattice structure. Also, the numerical results showed that applying a load above 441 N resulted in
a sharp decrease in the fatigue life of the lattice structure from 107
 cycles to 5.5×104
 cycles. It
was shown that an increase in the fatigue strength factor from 0.81 to 0.87 improved the fatigue
life about 100 times. Therefore, improving the surface roughness of the bio-compatible dental
implant could be one of the major factors that could increase the implant fatigue resistance and
should be considered through the design optimization of the dental implant.",,,,,,
"['Wu, Maxwell', 'Sammons, Patrick M.', 'Barton, Kira']",2021-11-03T21:24:53Z,2021-11-03T21:24:53Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89936,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['electrohydrodynamic jet printing', 'CFD', 'modeling']",Numerical Modeling of High Resolution Electrohydrodynamic Jet Printing Using OpenFOAM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7c95cb18-6483-495e-837c-4ee54c401e64/download,University of Texas at Austin,"Electrohydrodynamic jet (e-jet) printing is a micro-/nano-scale additive manufacturing
(AM) method that has emerged in recent years as a process to rival similar technologies such as
inkjet printing. By utilizing electrostatic forces to induce fluid flow, e-jet has shown the ability to
fabricate high resolution features with a wide variety of materials. Because it is a relatively new
AM process, the printing behavior of many different types of inks are not completely understood,
as existing knowledge of the process relies almost entirely on empirical methods that can be time
intensive and difficult to implement for materials that are hazardous or not readily available. This
paper discusses procedures for modeling both the electric and fluid dynamics of the e-jet printing
process within OpenFOAM, an open-source computational fluid dynamics (CFD) solver. Further
discussion has been provided to show simulations of the process at typical high resolution e-jet
printing scales and to present existing limitations of the model.",,,,,,
"['Comminal, R.', 'Serdeczny, M.P.', 'Pederson, D.B.', 'Spangenberg, J.']",2021-11-15T20:51:13Z,2021-11-15T20:51:13Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90267', 'http://dx.doi.org/10.26153/tsw/17188']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['material deposition', 'contouring precision', 'fused deposition modeling', 'numerical model']",Numerical Modeling of the Material Deposition and Contouring Precision in Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a1b1c3e0-5b05-4a91-8ed9-9d94d32690a0/download,University of Texas at Austin,"We present a numerical model of the material deposition in fused deposition modeling. The
flow of the material extruded from the printing head nozzle is simulated within the computation
fluid dynamics (CFD) paradigm. The molten thermoplastic is modeled as an incompressible
Newtonian fluid with a free surface. The numerical model provides a prediction of the shape of the
printed road. Four deposition strategies are investigated to print a road along a tool path with a 90°
turn. The investigated scenarios include the ideal case of an extrusion rate synchronized with the
printing speed, as well as the cases of a sharp tool path with a stop-at-turn trajectory, and a
smoothed tool path with blended acceleration. The CFD simulation provides a way to optimize the
tool path planning and the deposition strategy, in order to improve dimensional accuracy in
extrusion-based additive manufacturing.",,,,,,
"['Serdeczny, Marcin P.', 'Comminal, Raphaël', 'Pederson, David B.', 'Spangenberg, Jon']",2021-11-15T20:48:44Z,2021-11-15T20:48:44Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90266', 'http://dx.doi.org/10.26153/tsw/17187']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['printing parameters', 'porosity', 'fused deposition modeling']",Numerical Prediction of the Porosity of Parts Fabricated with Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4ce2437d-8813-4f22-82b7-44fc8d1ae04a/download,University of Texas at Austin,"In this paper, we study the effect of the printing parameters, namely the layer thickness and the strand-to-strand distance, on the porosity of components produced with Fused Deposition Modeling (FDM). The
FDM process is based on the extrusion of a melted material through a nozzle, which forms a 3D object, layer
by layer from the subsequent deposition of strands. Previous numerical modeling and experimental studies
have showed that the cross-section of the strands depends on the printing parameters. Using computational
fluid dynamics simulations, we predict the shape of the cross-sections of multiple strands printed next to
each other, and we estimate the porosity of the part. The results of this study show that the porosity of the
parts produced by FDM can be controlled by adjusting the printing parameters.",,,,,,
"['Mollah, Tusher', 'Comminal, Raphaël', 'Serdeczny, Marcin P.', 'Pederson, David B.', 'Spangenberg, Jon']",2021-12-07T17:29:35Z,2021-12-07T17:29:35Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90731', 'http://dx.doi.org/10.26153/tsw/17650']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['yield stress', 'layer stability', 'viscoplastic materials', 'multilayer printing', 'numerical modeling']",Numerical Predictions of Bottom Layer Stability in Material Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fbbc11a-4cd4-43aa-8890-17722ae75e73/download,University of Texas at Austin,"Robocasting and 3D concrete printing are technologies that belong under the umbrella term
material extrusion additive manufacturing. These two free form fabrication methods are used to
produce 3D structures/components in materials such as ceramic pastes, thermosets, and concrete.
Common for the materials is their viscoplastic behavior during deposition and structural buildup
(i.e., increase in yield stress) after deposition. The material’s complex nature makes it a nontrivial task to ensure that printed layers do not deform when depositing additional layers on top.
In this paper, we numerically investigate the influence of the yield stress buildup of viscoplastic
materials on the stability of the bottom layer during multilayer printing. Specifically, we have
developed a computational fluid dynamics model that applies a scalar approach to alter the yield
stress. The novel model provides fundamental knowledge on how to design the material’s
rheology, so the bottom layer can withstand both the hydrostatic- and extrusion-pressure.",,,,,,
"['Zhou, X.M.', 'Zhang, H.O.', 'Wang, G.L.', 'Liang, L.Y.', 'Fu, Y.H.', 'Bai, X.W.', 'Wang, X.P.']",2021-10-19T18:15:07Z,2021-10-19T18:15:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89315,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['arc based additive manufacturing', 'external longitudinal static magnetic field', 'magnetic field', 'numerical simulation']",Numerical Simulation and Experimental Investigation of Arc Based Additive Manufacturing Assisted with External Longitudinal Static Magnetic Field,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dd37dab6-a6c0-4033-95df-d392be1a7d05/download,University of Texas at Austin,"This paper proposes a new arc based additive manufacturing method assisted with external longitudinal
static magnetic field. An electromagnetic coupling numerical model has been established, which consists of
droplet impingement, heat transfer and dynamics of molten pool. Comparing the simulation results between
normal deposition and external longitudinal magnetic filed assisted deposition, it shows that the external
longitudinal static magnetic field induces the tangential stirring force in molten pool and drives the molten
metal moving to the edge of the pool. This can reduce the temperature gradient in forming region. Furthermore,
the related comparison experiments of single-bead deposition and multi-beads overlapping deposition are
performed, it was found that the tangential stirring force can reduce the height of single-bead as well as increase
the width of single-bead. The experimental results are in accordance with the simulation results. The changing
of morphology of the bead is beneficial to multi-beads overlapping and capable of improving the surface
accuracy for arc based additive manufacturing parts.",,,,,,
"['Fan, Zhiqiang', 'Jambunathan, Anand', 'Sparks, Todd E.', 'Ruan, Jianzhong', 'Yang, Yu', 'Bao, Yaxin', 'Liou, Frank']",2020-03-02T15:44:28Z,2020-03-02T15:44:28Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80138', 'http://dx.doi.org/10.26153/tsw/7159']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Computer Aided Design,Numerical Simulation and Prediction of Dilution During Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc2073a0-9057-4a1e-9f88-3c8eb4682d29/download,,"The laser additive manufacturing technique of laser deposition allows quick fabrication of
fully-dense metallic components directly from Computer Aided Design (CAD) solid models.
The applications of laser deposition include rapid prototyping, rapid tooling and part
refurbishment. The development of an accurate predictive model for laser deposition is
extremely complicated due to the multitude of process parameters and materials properties
involved. In this work, a heat transfer and fluid flow model is developed. The model is used to
predict dilution under varying process parameters for deposits of Ti-6Al-4V. Experimental
validation of the predicted dilution is presented. The laser used is a direct diode laser.",,,,,,
"['Dai, K.', 'Klemens, P.', 'Shaw, L.']",2019-09-23T16:43:06Z,2019-09-23T16:43:06Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75964', 'http://dx.doi.org/10.26153/tsw/3063']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Densification,Numerical Simulation of Bi-Materials Laser Densification 386,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1de69a30-8d1d-43e2-8116-85b47b636a3e/download,,"The dominant procedure currently used for permanent fixed prosthodontics is porcelainfused-to-metal (PFM) restoration that is a time consuming and labor intensive process. To address these shortcomings, this project will develop a solid freeform fabrication (SFF) technique for dental restoration. Thus, a dental restoration can be built from a computer model without part-specific tooling and human intervention. The SFF technique to be developed is called multi-materials laser densification (MMLD) and capable of dealing with multiple dental materials such as dental alloys and porcelains. In order to provide guidelines for laser
densification of multiple materials, numerical simulation has been carried out using the ANSYS code with 3-dimensional elements to model the temperature and stress fields during the MMLD process. Effects of laser scanning patterns and scanning rates have been investigated. Implications of these results on laser densification of multiple materials are discussed.",The authors gratefully acknowledge financial support provided bythe National Science Foundation under Grant No: DMI-9908249.,,,,,
"['Li, Mingyang', 'Tang, Lie', 'Xue, Fei', 'Landers, Robert']",2021-10-04T21:41:24Z,2021-10-04T21:41:24Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88357', 'http://dx.doi.org/10.26153/tsw/15296']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['ceramic paste extrusion', 'numerical simulation', 'non-Newtonian flow']",Numerical Simulation of Ram Extrusion Process for Ceramic Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6277c698-8e09-4e81-9672-c06a40c3c94b/download,University of Texas at Austin,"The freeze–form extrusion process for aqueous–based ceramic paste is complex due to the non–
Newtonian behavior of the paste. In this paper the process is studied numerically using a
developed mathematical model. The ceramic paste viscosity is characterized by the Herschel–Bulkley model. The relationship between plunger velocity and extrusion force is computed
numerically. The influence of air, which is mixed with the paste during the loading process, is
also examined. Due to the compressibility introduced by the trapped air, the plunger force
dynamic response is typically dominated by a first order response. It is also shown that the
extrusion plunger force depends on the volume of air in the extruder. Good agreement is
obtained between the simulation results and experimental data.",,,,,,
"['Shimono, Yusuke', 'Oba, Mototeru', 'Nomoto, Sukeharu', 'Koizumi, Yuichiro', 'Chiba, Akihiko']",2021-11-03T20:39:29Z,2021-11-03T20:39:29Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89927,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['multi-phase field method', 'soldification', 'simulation', 'titanium alloy', 'additive manufacturing', 'MPFM']",Numerical Simulation of Solidification in Additive Manufacturing of Ti Alloy by Multi-Phase Field Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ab6ba81-888f-4a86-980c-a6c4b41ad20a/download,University of Texas at Austin,"The multi-phase field method (MPFM) coupled with the database of calculation of phase diagrams
(CALPHAD) is a powerful tool for simulation of solidification microstructure evolution in engineering casting
conditions. MPFM equations have been introduced assuming quasi-equilibrium at the interface. However, few
attempts have been made adopting MPFM for solidification in additive manufacturing (AM) conditions because
the process is considered to be in a strongly non-equilibrium condition. In other words, the classical solidification
theory based on the local equilibrium assumption was not considered to be applicable to this process. However,
some researchers have reported experimental observations of the columnar-to-equiaxed transition in the
solidification of AM. These suggest MPFM can be adopted for solidification simulation of the AM process. We
tackled the issue of applicability of MPFM for solidification simulation in AM of Ti alloys. It was confirmed that
solidification simulation using MPFM can provide observation of the columnar-to-equiaxed transition and
establish a solidification map for the AM process conditions.",,,,,,
"['Luo, Zhibo', 'Zhao, Yaoyao Fiona']",2021-11-03T21:16:15Z,2021-11-03T21:16:15Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89934,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['hybrid heat source', 'Gaussian point', 'line heat source', 'temperature field', 'powder bed fusion']",Numerical Simulation of Temperature Fields in Powder Bed Fusion Process by Using Hybrid Heat Source Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11ac5719-065d-4719-9042-24cb348af682/download,University of Texas at Austin,"Powder bed fusion (PBF) process is capable of producing a complex geometrical part
with less material and energy consumption compared with conventional manufacturing methods.
The performance of PBF processed part is mainly controlled by many process parameters such as
scanning speed, scanning pattern, scanning strategy, and layer thickness. Usually, these
parameters are optimized through detailed experiments which are time-consuming and costly.
Therefore, numerical methods have been widely adopted to investigate the effects of these
process parameters on temperature fields and thermal stress fields. As the laser/electron beam
introduces huge temperature gradients within the irradiated region, which will result in the
distortion even delamination of solidified layers, the study of the history of temperature
distribution is the basic and crucial step in the modeling of PBF process. Most of the current
research utilizes moving Gaussian point heat source as heat input to model the temperature
distribution of a part. However, due to the small diameter of laser/electron beam, a small enough
time step size is required to accurately model the real heat input, which will lead to significant
computational burden. In this research, a hybrid of moving Gaussian point and line heat source
model is developed, which makes the modeling of PBF process efficient without losing too much
accuracy. In addition, an adaptive mesh scheme, which is capable of dynamically refining the
mesh near the beam spot and coarsening the mesh far away from the beam spot, is adopted to
accelerate the simulation process. Specifically, moving Gaussian point heat source is applied to
the region of interest where accuracy is more concerned such as the temperature field within
overhang feature. While the line heat source is applied to the region of interest where efficiency
is more concerned such as temperature field within the inner region of a square. The simulation
result shows that the temperature fields by using hybrid source model are comparable to the
temperature fields by using the moving Gaussian point heat source model, and much less central
processing unit time is required when the hybrid heat source is applied.",,,,,,
"['Fan, Zhiqiang', 'Sparks, Todd E.', 'Liou, Frank', 'Jambunathan, Anand', 'Bao, Yaxin', 'Ruan, Jianzhong', 'Newkirk, Joseph W.']",2020-03-09T15:09:00Z,2020-03-09T15:09:00Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80192', 'http://dx.doi.org/10.26153/tsw/7211']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Computer Aided Design,Numerical Simulation of the Evolution of Solidification Microstructure in Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0141a173-6643-497d-b4bd-c10a8847b02e/download,,"A predictive model is developed to simulate the evolution of the solidification microstructure
during the laser deposition process. The microstructure model is coupled with a
comprehensive macroscopic thermodynamic model. This model simulates dendritic grain
structures and morphological evolution in solidification. Based on the cellular automata
approach, this microstructure model takes into account the heterogeneous nucleation both
within the melt pool and at the substrate/melt interface, the growth kinetics, and preferential
growth directions of dendrites. Both diffusion and convection effects are included. This
model enables prediction and visualization of grain structures during and after the deposition
process. This model is applied to Ti-6Al-4V.",,,,,,
"['Wang, L.', 'Felicelli, S.', 'Gooroochurn, Y.', 'Wang, P. T.', 'Horstemeyer, M. F.']",2020-03-02T15:26:13Z,2020-03-02T15:26:13Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80132', 'http://dx.doi.org/10.26153/tsw/7153']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Engineered Net Shaping,Numerical Simulation of the Temperature Distribution and Solid-Phase Evolution in the LENS™ Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd67216f-b9cf-4335-9c46-7c202f0f9049/download,,"A three-dimensional finite element model was developed and applied to analyze the
temperature and phase evolution in deposited stainless steel 410 (SS410) during the Laser
Engineered Net Shaping (LENSTM) rapid fabrication process. The effect of solid phase
transformations is taken into account by using temperature and phase dependent material
properties and the continuous cooling transformation (CCT) diagram. The laser beam is modeled
as a Gaussian distribution of heat flux from a moving heat source with conical shape. The laser
power is optimized in order to achieve a pre-defined molten pool size for each layer. It is found
that approximately 5% decrease of the laser power for each pass is required to obtain a steady
molten pool size. The temperature distribution and cooling rate surrounding the molten pool are
predicted and compared with experiments. Based upon the predicted thermal cycles and cooling
rate, the phase transformations and their effects on the hardness are discussed.",,,,,,
"['Zeng, D.', 'Rebandt, Matthew', 'Lacaria, Giuseppe', 'Lee, Ellen', 'Su, Xuming']",2021-11-18T17:19:33Z,2021-11-18T17:19:33Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90434', 'http://dx.doi.org/10.26153/tsw/17355']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['numerical simulation', 'temperature history', 'plastic parts', 'fused filament fabrication', 'FFF']",Numerical Simulation of the Temperature History for Plastic Parts in Fused Filament Fabrication (FFF) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9d3d369-c22e-4c35-bd13-1e4064459495/download,University of Texas at Austin,"Fused Filament Fabrication (FFF) is one of the major Additive Manufacturing (AM)
processes for polymer materials. In FFF process, repetitive heating and cooling cycles occur when
the filament is dispositioned onto a build platform to fabricate a three-dimensional part. The
uneven temperature gradients and non-uniform cooling in the part may cause significant amount
of warpage. The current practice of making an AM part to match the design intent is largely relied
on time consuming trial-and-errors. Numerical simulation is an effective way to predict warpage.
Accurate prediction of the thermal history during the FFF process is key for the success of warpage
simulation. In this paper, an integrated approach is developed in LS-DYNA to model the FFF
process and predict the temperature profile. Different from the traditional approaches, the tool path
and FEM mesh are decoupled in this study to enable the flexibility of FEA mesh generation and
improve computational efficiency. An innovated micro thermocouple is used to measure the
temperature history inside the parts. The evolution of the thermal history is predicted and compared
to the measurement data to demonstrate the accuracy and efficiency of the developed simulation
model.",,,,,,
"Hsu, Michael B.",2018-04-19T18:12:28Z,2018-04-19T18:12:28Z,1992,Mechanical Engineering,doi:10.15781/T28C9RM8S,http://hdl.handle.net/2152/64399,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['creep models', ""Poisson's ratio"", 'apparent modulus']",Numerical Simulation of Viscous Sintering under Mechanical Loads,Conference paper,https://repositories.lib.utexas.edu//bitstreams/075814fc-7a8d-4e92-a6e2-61d088a96fd4/download,,,,,,,,
"['Tan, W.', 'Gibson, I.']",2020-02-20T19:45:29Z,2020-02-20T19:45:29Z,8/3/05,Mechanical Engineering,,https://hdl.handle.net/2152/80044,eng,2005 International Solid Freeform Fabrication Symposium,Open,"['microstereolithography', 'recoating process', 'numerical simulation']",Numerical Study on the Recoating Process in Microstereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f27c30a-38e1-4d75-b0e3-5abc51ce16cd/download,,"Microstereolithography is a promising RP-based micro-fabrication technique that aims to
meet the demands for complex geometry micro-scale parts. Projection microstereolithography
incorporates a Dynamic Pattern Generator to obtain high resolution in the parallel plane.
However, its lateral resolution has been always limited by the final layer thickness and the long
resin settling time, both of which rely on the recoating process. In order to find the critical
factors behind the recoating process, a numerical simulation method (Computational Fluid
Dynamics, CFD) has been used to investigate the relationships among final layer thickness,
settling time, resin viscosity and ratio of object/container size. These results are helpful for the
selection of resin characteristics and the design of the microstereolithography machine.",,,,,,
"['Shen, Ninggang', 'Chou, Kevin']",2021-10-06T21:33:55Z,2021-10-06T21:33:55Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88451', 'http://dx.doi.org/10.26153/tsw/15388']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['electron beam additive manufacturing', 'thermal models', 'preheating temperatures', 'complex process configurations', 'temperature field']",Numerical Thermal Analysis in Electron Beam Additive Manufacturing with Preheating Effects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8bc4626f-e4aa-4290-98d3-f03a61b463df/download,University of Texas at Austin,"In an early study, a thermal model has been developed, using finite element simulations,
to study the temperature field and response in the electron beam additive manufacturing (EBAM)
process, with an ability to simulate single pass scanning only. In this study, an investigation was
focused on the initial thermal conditions, redesigned to analyze a critical substrate thickness,
above which the preheating temperature penetration will not be affected. Extended studies are
also conducted on more complex process configurations, such as multi-layer raster scanning,
which are close to actual operations, for more accurate representations of the transient thermal
phenomenon.",,,,,,
"['Ikeshoji, T.-T.', 'Kyogoku, H.', 'Yonehara, M.', 'Araki, M.', 'Nakamura, K.']",2021-10-26T19:18:47Z,2021-10-26T19:18:47Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89562,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'nickel alloy', 'numerical transient analysis', 'heat transfer', 'powder bed', 'multilayer track']",Numerical Transient Heat Transfer Analysis of Multi Laser Track on Powder Bed of Ni-Based Alloy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ffdbd6e-8cbc-45aa-aa9a-62ed86848834/download,University of Texas at Austin,"The numerical transient heat transfer analysis is conducted for SLM process of Ni-based
alloy. For the initial situation, the powder layer covers all the top surface of bulk substrate. Then
it is simulated a laser spot scans one and half times of round trips. To simulate the melting of
powder layer and its solidification, the powder elements are changed to the bulk when the
powder element’s temperature reaches to liquidus. The results show the change in melt pool
shape. It is symmetry about scanning direction axis for the first path, but the second and third
paths’ melt pool is wider on the solidified side. The melt pool dimensions are compared with the
experimentally obtained thermography images. The estimated melt pool depth is also compared
with the metallographic microstructure image of cross section. The results might suggest the
one-path simulation is not enough for the prediction of solidified track of SLM process.",,,,,,
"['Nzebuka, Gaius Chukwuka', 'Ufodike, Chukwuzubelu Okenwa']",2023-02-17T14:46:13Z,2023-02-17T14:46:13Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117486', 'http://dx.doi.org/10.26153/tsw/44367']",eng,2022 International Solid Freeform Fabrication Symposium,Open,filament,Numerical Transient Thermal Development of Melting a Solid Filament in a Hot-end of a Material Extrusion System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/22c1cef6-8927-425e-a8f7-ed554a46d058/download,,"Additive manufacturing of polymer feedstock in the form of solid filament is challenging 
due to heat transfer limitations. The ease of melting the filament in the liquefier influences the 
production rate and life cycle of the hot-end components. This study presents numerical transient 
thermal development during the melting of the solid filament in the liquefier. The sample filament 
material selected for the study is a tough polylactic acid (TPLA). The transient computation of 
thermal distribution and liquid fraction evolution was performed using computational fluid 
dynamics (CFD) commercial software. However, the numerical model formulations cannot be 
directly applied to the available CFD software. Therefore, a user-defined function (UDF) was 
written and interfaced with the CFD software for the properties field-dependent functions. Special 
care was taken to capture the motion of the solid filament by patching the velocity explicitly in the 
flow domain. One simulation was performed without accounting for the velocity of the translating 
solid filament and the result obtained revealed that the case that accounts for the velocity of the 
solid filament predicts the infrared thermographic measured nozzle exit temperature of the 
extrudate more accurately. Also, a steady thermal development was achieved in the hot end after 
25 seconds. The transient thermal analysis can be useful for a better understanding of melting 
dynamics in the liquefier and assist in process control planning.",,,,,,
"['Chung, Marilyn', 'Malone, Evan', 'Tolley, Michael T.', 'Chepaitis, Andrew J.', 'Lipson, Hod']",2021-09-23T22:47:43Z,2021-09-23T22:47:43Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88046', 'http://dx.doi.org/10.26153/tsw/14987']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping technology', 'object augmentation', 'visually impaired']",Object Augmentation for the Visually Impaired Using RP,Conference paper,https://repositories.lib.utexas.edu//bitstreams/083eda81-318e-40a7-b478-d9c3af49f6b5/download,,"We demonstrate the application of rapid prototyping technology to augment every-day objects for
the visually impaired. A freeform fabricator was used to print a tactile alphabet on multiple
surfaces including paper, plastic, and metal. We have identified and experimented with multiple
non-toxic materials and analyzed the dimensional tolerance, repeatability, and adhesion
characteristics on multiple surfaces. Printing time for 1x1cm embossed letters varied from 14 to 52
seconds. More broadly, these experiments open the door to RP applications that involve custom
product adaptation to address disabilities.",,,,,,
"['Tilli, J.', 'Fantoni, G.', 'Currenti, S.', 'Razionale, A.V.']",2021-10-12T20:26:52Z,2021-10-12T20:26:52Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88733', 'http://dx.doi.org/10.26153/tsw/15667']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'removal manufacturing', 'object shaping', 'polystyrene', 'sonotrode']",Object Shaping of Polystyrene with a Sonotrode,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee8e8702-bb59-4181-badd-d6a0c67dafab/download,University of Texas at Austin,"Rapid Prototyping methods are often based on additive manufacturing strategies.
Depending on the application, it can also be considered the use of a removal manufacturing
rapid prototyping methodology. In this paper the authors investigate the possibility of using
the ultrasound technology for the shaping of materials that can be considered as a final object,
or as a rapid manufactured mold for the creation of prototypes. In this case, free-form objects
can be manufactured starting from foam like materials, and model the foam through the use of
a ultrasonic horn thus shaping the desired features. The authors tested the possibility of
implementing the technology onto automated systems, allowing considering the use of this
system on automated manufacturing lines. Geometrical deviations from the 3D model are
measured and material morphology before and after machining is analyzed.",,,,,,
"['Landers, Robert G.', 'Hilgers, Michael', 'Liou, Frank W.', 'McMillin, Bruce M.']",2019-10-23T15:10:45Z,2019-10-23T15:10:45Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76756', 'http://dx.doi.org/10.26153/tsw/3845']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Object-Oriented,Object-Oriented Modeling and Fault Detection of a Powder Feeder for a Laser Metal Deposition System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/528375a8-6a3d-4be2-a4ca-07a9eb7375e9/download,,"One of the most critical components of a laser metal deposition system is the powder feeder unit.
Techniques are required to efficiently design and analyze these systems and to ensure fault
tolerance during the operation. In this paper, a model of the powder feeder unit, based on object–
oriented abstractions of it components, is developed. This model is modular in that specific
components can be efficiently updated or replaced with components that perform a similar
function. In addition, the model can be used for simulation allowing for efficient design and
analysis. Assurance of the correctness of the powder feeder system is obtained from concurrent
run–time evaluation of temporal logic expressions. A simulation example is provided.","The authors gratefully acknowledge their students’ contributions to this paper and the financial
support of the National Science Foundation (DMI–9871185), Missouri Research Board, Society
of Manufacturing Engineers, and Missouri Department of Economic Development.",,,,,
"['Scharowsky, T.', 'Baureiβ, A.', 'Singer, R.F.', 'Körner, C.']",2021-10-06T21:48:08Z,2021-10-06T21:48:08Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88454', 'http://dx.doi.org/10.26153/tsw/15391']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['selective electron beam melting', 'beam powder interaction', 'melt pool dynamic', 'Ti6Al4V']",Observation and Numerical Simulation of Melt Pool Dynamic and Beam Powder Interaction During Selective Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b98b93a-ca59-41b8-ba91-d29b80119e56/download,University of Texas at Austin,"Selective electron beam melting (SEBM) is an additive manufacturing method used to
produce complex parts in a layer-by-layer process utilizing Ti6Al4V powder. To improve the
very good properties of built parts even more and to use the full capacity of the process, the
fundamental understanding of the beam powder interaction is of essential relevance.
Numerical simulations and observation with a high speed camera of powder melting show the
strong melt pool dynamic and its lateral extent clearly. Furthermore, the immediate effect of
beam parameters, e.g. beam current and velocity, on the melting behavior of the powder can
be resolved in time steps of a few milliseconds.",,,,,,
"['Lawrence, Jacob', 'Inkley, Colton', 'Fezzaa, Kamel', 'Clark, Samuel J.', 'Crane, Nathan B.']",2023-01-27T17:58:23Z,2023-01-27T17:58:23Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117350', 'http://dx.doi.org/10.26153/tsw/44231']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Binder Jetting', 'Synchrotron X-ray Imaging', 'Binder-Powder Interaction', 'Print  Processing Parameters', 'Metal']",Observations of Binder Jetting Defect Formation Using High-Speed Synchrotron X-Ray Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a47cb13e-f9a9-4246-ac5d-49bb7349ca93/download,,"The Binder Jetting (BJ) process is capable of producing parts at high speeds from a variety 
of materials, but performance is limited by defects in the final parts. An improved understanding 
of fundamental phenomena in the printing process is needed to understand the source of these 
defects. This work presents initial findings from high-speed imaging of the BJ process using 
synchrotron X-rays. High-speed X-ray imaging allows for direct observation of key physical 
mechanisms in the printing process that may introduce defects including binder droplet impact on 
the powder bed, powder rearrangement below and above the powder bed surface, and balling 
formation. Testing was performed with multiple materials and droplet spacings to compare the 
effect on observed phenomena. Multiple lines were printed on packed and loose powder beds to 
further explore factors that affect defect formation and to better simulate industrially relevant 
conditions.",,,,,,
"['Dhaveji, Ch. Sweta', 'Sparks, Todd E.', 'Ruan, Jianzhong', 'Liou, Frank W.']",2021-10-04T21:49:40Z,2021-10-04T21:49:40Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88360', 'http://dx.doi.org/10.26153/tsw/15299']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing toolpath', 'machine simulation', 'multi axis AM']",Octree Approach for Simulation of Additive Manufacturing Toolpath,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e1bb96a2-6fb4-4f05-9357-267ed0773327/download,University of Texas at Austin,"Machine simulation is an effective way of checking additive manufacturing tool paths for both interferences and errors in part
produced. This paper presents an algorithm to visually simulate a multi axis additive manufacturing system as it executes a process plan. Simulation results are intended to be used as a verification step before physically producing the part. Verification is
particularly important for large builds of expensive materials. The algorithm uses an octree approach to efficiently model the
deposition of part geometry and its changes. This paper discusses development of the simulation algorithm, including both the
representation of the additive manufacturing machine and the octree data model of the part being produced.",,,,,,
"['Tang, Hwa-Hsing', 'Yen, H.C.', 'Len, Wen-Hsiang']",2019-11-21T18:04:29Z,2019-11-21T18:04:29Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78550', 'http://dx.doi.org/10.26153/tsw/5606']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Rapid Prototyping,On Ceramic Parts Fabricated Rapid Prototyping Machine Based on Ceramic Laser Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9659a125-28ca-4e36-adff-7f2b7a927cb3/download,,"Conventional ceramic manufacture processes are not feasible to make ceramic parts with
complex shape because of restrictions such as high tooling cost, time consuming and skillful
workmanship. A new facility taking advantage of patented Ceramic Laser Fusion (CLF)
technology to fabricate complex ceramic parts automatically is developed. According to the
samples made by CLF machine, they are verified that hollow and over hung structures can be
supported by solid green portion and complex ceramic parts can be fabricated. Apparently, this
facility could promote the applications of ceramic materials, such as direct fabrication of ceramic
shell mold.",,,,,,
"['Papadatos, Alexandre L.', 'Ahzi, Said', 'Deckard, Carl R.', 'Paul, Frank W.']",2018-12-07T17:10:44Z,2018-12-07T17:10:44Z,1997,Mechanical Engineering,doi:10.15781/T2BR8N26F,http://hdl.handle.net/2152/71451,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['dimensional stabilities', 'Rapid prototyping']",On dimensional stabilities: Modeling of the Bonus-Z during the SLS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c51c4197-a193-40cb-8baa-b498711705e5/download,,"This work is a first step towards the prediction of the dimensions and thermomechanical
properties ofparts made with the Selective Laser Sintering (SLS) technology.
An important variation of the dimensions is found in the Z-direction of the build. This
phenomenon is known as the ""Bonus-Z"" where material properties differ from those in
the rest of the part due to a non-homogeneous sintering. The focus of this work is the
characterization and the modeling of the bonus-Z phenomenon, by relating it to the
energy input. The polymer powder used in this study is polycarbonate.",,,,,,
"['Thien, Austen', 'Kelly, Kathryn M.', 'Massey, Caroline E.', 'Saldana, Christopher J.']",2024-03-26T23:17:04Z,2024-03-26T23:17:04Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124446', 'https://doi.org/10.26153/tsw/51054']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['wire-arc additive manufacturing', 'stability', 'aluminum alloy']",ON PROCESS STABILITY IN WAAM-CMT OF ALUMINUM ALLOYS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4624232-4d1a-4b35-8bcf-ba16bcd8a916/download,University of Texas at Austin,"Wire-arc additive manufacturing (WAAM) has become a cost-efficient metal additive
manufacturing process. However, depositing aluminum with WAAM is challenging due to its
sensitivity to heat input (linear energy density), which can cause undesirable surface topology
waviness if not controlled. Thus, a process window is needed that can produce stable geometry
and deposition conditions while minimizing production times. In this study, 5183 aluminum
alloy wire is used to deposit 10-layer walls with varying wire feed speeds (WFS) and traverse
speeds (TS) (at a constant WFS/TS ratio) and varying interpass temperature (IPT). In-situ
process data consisting of optical contact-tip-workpiece-distance (CTWD) and current/voltage
measurements are collected to determine process condition stability throughout the build. Part
geometry is measured using a 3D scanner and build porosity is characterized via digital X-ray.
A process window is identified that produces stable surface topology and process conditions at
a minimal production time.",,,,,,
"Das, Suman",2019-10-09T16:15:31Z,2019-10-09T16:15:31Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76151', 'http://dx.doi.org/10.26153/tsw/3240']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sintering,On Some Physical Aspects of Process Control in Direct Selective Laser Sintering of Metals Part I,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f629627a-7dba-411a-8ae1-57b45757085b/download,,,,,,,,
"Das, Suman",2019-10-09T16:17:13Z,2019-10-09T16:17:13Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76152', 'http://dx.doi.org/10.26153/tsw/3241']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sintering,On Some Physical Aspects of Process Control in Direct Selective Laser Sintering of Metals Part II,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44409a12-9f12-49a6-86e6-ee89e7eff871/download,,,,,,,,
"Das, Suman",2019-10-09T16:18:26Z,2019-10-09T16:18:26Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76153', 'http://dx.doi.org/10.26153/tsw/3242']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sintering,On Some Physical Aspects of Process Control in Direct Selective Laser Sintering of Metals Part III,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b5b84ff-de0e-40cc-bfce-bbaa56b570ef/download,,,,,,,,
"['Allen, Seth', 'Dutta, Deba']",2018-10-03T15:51:40Z,2018-10-03T15:51:40Z,1994,Mechanical Engineering,doi:10.15781/T24F1N368,http://hdl.handle.net/2152/68653,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Layered manufacturing', '3D System machines', 'photocurable liquid']",On the Computation Of Part Orientation Using Support Structures in Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/92effa27-1c59-4792-822e-50a4e5e951a0/download,,"During the construction of an object by layered manufacturing, it might be
necessary to build external supports either to prevent the object from toppling, or to support
floating components and overhanging material. The support structures, if necessary, must
be built simultaneously with the object, and hence must be accounted for in the path
planning of the laser beam or the deposition nozzle. In this paper, we find the best direction
offormation of an object by layered manufacturing process that allows the use of support
structures. In the orientation determined by the best direction offormation, the object is
constructible with a minimal support structure, is stable, and rests on a planar base.
Implementation results are also included.",,,,,,
"['Wood, Nathaniel', 'Schwalbach, Edwin', 'Gillman, Andrew', 'Hoelzle, David J.']",2021-12-01T22:28:47Z,2021-12-01T22:28:47Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90639', 'http://dx.doi.org/10.26153/tsw/17558']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'ensemble kalman filter', 'thermal camera', 'camera resolution']",On the Diminishing Returns of Thermal Camera Resolution for PBF Temperature Estimation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68cc0198-20ba-4bbb-bec0-8c6054d1afca/download,University of Texas at Austin,"Powder Bed Fusion (PBF) faces ongoing challenges in the areas of process monitoring and
control. Standard methods for alleviating these issues rely on machine learning, which requires
costly and time-consuming training data. Expense is compounded by the perceived necessity
of using sensors with extremely high resolutions. This research avoids this cost by employing
an Ensemble Kalman Filter (EnKF), which uses measured data to correct physics-based model
predictions of the process, to monitor part internal temperature fields during building. This
work tests EnKF performance, in simulation, for two model architectures, using simulated
cameras of varying resolution as our measuring instruments. Crucially, we show that increasing camera resolution produces diminishing returns in EnKF accuracy, relative to the model
predictions, with up to 81% error reduction. This result shows that current AM quality control practices with expensive sensors may be inefficient; with appropriate algorithms, cheaper
setups may be used with little additional error.",,,,,,
"['Goossens, Louca R.', 'Kinds, Yannis', 'Kruth, Jean-Pierre', 'Van Hooreweder, Brecht']",2021-11-15T22:39:02Z,2021-11-15T22:39:02Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90299', 'http://dx.doi.org/10.26153/tsw/17220']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['thermal lensing', 'focal shift', 'high power laser', 'control', 'SLM']",On the Influence of Thermal Lensing During Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/14391a10-9f34-4b6c-a43e-6fc5bdd840a0/download,University of Texas at Austin,"Multi kilowatt single mode lasers are increasingly being used in Selective Laser Melting
(SLM), typically with the aim of improving productivity. However, the high power densities
present in the optical path lead to a thermally induced focal shift i.e. thermal lensing. Whilst
thermal lensing has been studied for many processes, its impact on parts produced by SLM is
currently unknown. Therefore this work discusses the characteristics of a thermally induced
focal shift supplemented by a method for the compensation of this effect. In addition, SLM
parts with and without thermal lensing compensation are compared in order to show the effect
on final part quality.",,,,,,
"['Gill, D.D.', 'Smugeresky, J. E.', 'Harris, M. F.', 'Robino, C. V.', 'Griffith, M. L.']",2020-02-14T15:22:44Z,2020-02-14T15:22:44Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79984', 'http://dx.doi.org/10.26153/tsw/7009']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Laser Engineered Net Shaping,On the Interface Between LENS® Deposited Stainless Steel 304L Repair Geometry and Cast or Machined Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc812b8a-9bf7-46fe-b267-c2ca3995ff9c/download,,"Laser Engineered Net Shaping™ (LENS®) is being evaluated for use as a metal component
repair/modification process. A component of the evaluation is to better understand the characteristics of
the interface between LENS deposited material and the substrate on which it is deposited. A processing
and metallurgical evaluation was made on LENS processed material fabricated for component
qualification tests. A process parameter evaluation was used to determine optimum build parameters
and these parameters were used in the fabrication of tensile test specimens to study the characteristics of
the interface between LENS deposited material and several types of substrates. Analyses of the
interface included mechanical properties, microstructure, and metallurgical integrity. Test samples
were determined for a variety of geometric configurations associated with interfaces between LENS
deposited material and both wrought base material or previously deposited LENS material. Thirteen
different interface configurations were fabricated for evaluation representing a spectrum of deposition
conditions from complete part build, to hybrid substrate-LENS builds, to repair builds for damaged or
re-designed housings. Good mechanical properties and full density were observed for all configurations.
When tested to failure, fracture occurred by ductile microvoid coalescence. The repair and hybrid
interfaces showed the same metallurgical integrity as, and had properties similar to, monolithic LENS
deposits.",,,,,,
"['Casanova, Lucas', 'Anitha, Vineeth Vijayan', 'Kadway, Nikhil', 'Gandhi, Arpit', 'Le, Thao', 'Lee, Christine', 'Bhate, Dhruv']",2021-11-09T20:13:17Z,2021-11-09T20:13:17Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90153', 'http://dx.doi.org/10.26153/tsw/17074']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['asymmetric honeycombs', 'mechanical behavior', 'material design', 'additive manufacturing']",On the Mechanical Behavior of Additively Manufactured Asymmetric Honeycombs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e3fec48-189c-4190-9bb5-c2d0981911df/download,University of Texas at Austin,"From a design perspective, there are four decisions that need to be made when integrating
cellular materials such as lattices and honeycombs into a structure: selection of the unit cell type,
distribution of the size of the cells across the structure, optimization of individual cell walls/struts
and junction thicknesses, and finally, integration of the cellular material with the outer form of the
larger structure it is a part of. In this paper, we explore an alternative approach to designing cellular
materials, borrowing concepts of symmetry from mathematics and the arts to manipulate 2-
dimensional square honeycombs of uniform thickness, starting from a regular, periodic square,
gradually varying symmetry and the number of shapes to create a range of forms. We report results
of compression testing of specimens made with the Fused Deposition Modeling process, and study
the effective specific properties of the honeycombs with regard to their peak stress at failure,
densification strain and energy absorption. We report weak to no correlation to the first two of
these, but demonstrate how asymmetry and negative space may be leveraged to formulate design
principles for energy absorption.",,,,,,
"['Sager, Benay', 'Rosen, David W.']",2020-02-14T16:18:56Z,2020-02-14T16:18:56Z,8/31/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79991', 'http://dx.doi.org/10.26153/tsw/7016']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Stereolithography,"On the Use of Angled, Dynamic Laser Beams to Improve Stereolithography Surface Finish",Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed15bf7b-4ffc-48a7-93b4-57eb806e11a2/download,,"Improved surface finish of Stereolithography (SLA) parts is an important goal for furthering
the resolution of the technology. In order to improve the surface finish, a dynamic laser beam
with changing angle, beam size, beam shape, and irradiance distribution is proposed. In this
paper, an analytical irradiance model of an angled, dynamic laser beam in the SLA process is
presented. This model is used to simulate cured shapes of SLA builds. Simulated build shapes
are compared to established SLA analytical models and conclusions are drawn on the accuracy
of the developed model.",,,,,,
"['Hyde, C.J.', 'Xu, Z.', 'Thompson, A.', 'Leach, R.K.', 'Maskery, I.', 'Tuck, C.J.', 'Clare, A.T.']",2021-11-02T14:41:03Z,2021-11-02T14:41:03Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89813,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['creep', 'two-bar specimen', 'x-ray computed tomography', 'laser powder bed fusion', 'inconel 718']",On the Use of X-Ray Computed Tomography for Monitoring the Failure of An Inconel 718 Two-Bar Specimen Manufactured by Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7de5b0b8-7ffa-4c59-b9e2-89844c3ff60f/download,University of Texas at Austin,"Additive manufacturing technologies are highly versatile, capable of producing components with
previously impossible complex geometries. However, when additive manufacturing is used to
produce parts for critical applications, such as in the aerospace sector, the parts are sometimes
limited by poor mechanical properties; largely as a result of porosity and lower material
homogeneity than found in, for example, a wrought equivalent. Presented here is a method for
identifying material defects, such as porosity, and for monitoring the progress of these defects
towards failure during a mechanical test. An Inconel 718 two-bar specimen, produced by laser
powder bed fusion, has been applied to a “staged” mechanical test, and X-ray computed
tomography used to measure the sample at the end of each “stage”. The X-ray computed
tomography data has then been used to provide a history of failure sites prior to failure.",,,,,,
"['Beascoechea, Alejandro', 'Wozny, Michael J.']",2018-11-02T17:05:34Z,2018-11-02T17:05:34Z,1995,Mechanical Engineering,doi:10.15781/T24J0BH0P,http://hdl.handle.net/2152/69341,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SFF technology', 'optimization', 'fabrication']",On Three Dimensional Heuristic Packing For Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ce55811f-464c-439f-b5f6-322673facc4d/download,,"Optimal packing, any dimension, is computationally intractable. Here we address the particular
problem of automatically generating good layouts of arbitrary solid three-dimensional shape models
into a container region that represents a given freeform fabrication manufacturing chamber. We
put forth a multistage approach that combines modem heuristic optimization methods with computational
geometry techniques. Our aim is to secure satisfactory and practical results for a problem
for which reaching optimal packing configurations is computationally unattainable.",,,,,,
"['Fouchal, F.', 'Knight, J.A.G.', 'Dickens, P.', 'Garrington, N.']",2019-10-18T16:11:32Z,2019-10-18T16:11:32Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76249', 'http://dx.doi.org/10.26153/tsw/3338']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Epoxy Resin,On-line Monitoring of Epoxy Resin Cure using Infrared Spectroscopy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa8356f9-11ce-4e5f-bd44-a134899eaa90/download,,"The method described can be used to observe the cure in epoxy resins, it is a sensor to
serve as an on line monitoring system of physical change of the resins during the curing time and
the future behaviour of the part built. It is also proposed that the method can be applied in
Stereolithography (SL). In this paper the method permits a rapid determination of the state of
chemical reaction happening in an epoxy resin diglycidyl ether of bisphenol A (DGEBA) with a
curing agent triethylenetetramine stoichiometric mixture. It uses a mid infrared Fourier transform
(FT-IR) technique to analyse the mixture via an embedded fibre optic and an FT-IR spectrometer
operating in the region of 4000-700 cm-1. An accurate concentration versus time of epoxy amine
and the hydroxyl groups gave a good estimate of the extent of reaction. The chemical group
peaks at 1132cm-1 and 3300-3400cm-1 where used to follow the disappearance of the epoxy, and
the amine respectively, while the peak at 2970cm-1 was used as reference peak. A review of a
number of techniques used in the study of the curing process of epoxy resins and a number of
methods used in an on-line monitoring of thermoset resin cure process is referred to
Keywords: Streolithography, epoxy/amine cure, FT-IR spectroscopy, extent of
reaction, fiber optic sensor.",,,,,,
"['Yang, Liu', 'Binega, Eden', 'Cheng, Jack C.P.', 'Jeon, Ikgeun', 'Sohn, Hoon']",2021-12-01T23:08:11Z,2021-12-01T23:08:11Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90649', 'http://dx.doi.org/10.26153/tsw/17568']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'laser line scanner', 'geometry quality', 'quality management', 'online management']",Online Geometry Quality Management during Directed Energy Deposition using Laser Line Scaner,Conference paper,https://repositories.lib.utexas.edu//bitstreams/efcc630c-c6ee-4db3-ac53-c33b79e6515d/download,University of Texas at Austin,"Additive manufacturing (AM) is a powerful and promising manufacturing
technology due to its advantages of material saving, mass customization and small-quantity production of custom-designed products. However, current situation of lacking
quality management in 3D printing process is the key barrier of adopting this advanced
technology. Geometry inaccuracy of 3D printed components is one of the main quality
problems for AM, especially when the final product requires high precision in its geometry.
In this study, an online geometry quality management method for continuous monitoring
during the direct energy deposition (DED) process was developed using a laser line
scanner. Our proposed methodology comprises: (1) real-time track-by-track scanning of
multi-layer single-track component, (2) online geometry extraction of multi-layer single-track component during printing process, and (3) online plotting and comparison of the
as-designed and as-built models.",,,,,,
"['Craeghs, Tom', 'Clijsters, Stijn', 'Yasa, Evren', 'Kruth, Jean-Pierre']",2021-10-04T21:21:50Z,2021-10-04T21:21:50Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88350', 'http://dx.doi.org/10.26153/tsw/15289']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'quality monitoring', 'quality control', 'online quality control']",Online Quality Control of Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed92c4ed-fd04-4ba7-a4c4-d84b790dea2e/download,University of Texas at Austin,"Selective Laser Melting (SLM) is an Additive Manufacturing technique which
allows producing three-dimensional metallic parts from powder material, using a layer-by-layer fashion. Typical applications of this technology are parts with high geometrical
complexity or internal features such as biomedical implants or casting molds with
conformal cooling channels. In order to break through in industries with very high quality
standards (such as aerospace industries), an important issue to be addressed is quality
monitoring and control during the actual building process. Online quality control can
significantly increase the robustness of the process by enabling to check the quality of the
building process in the earliest possible stage, such that eventually corrective actions can
be taken during the process. This is in contrast with on-line and a posteriori quality
control which does not allow taking corrective measures if the quality of the part does not
meet the desired quality standard. The development of a framework for online quality
control of Selective Laser Melting is the subject of this paper. The framework consists of
two complementary systems: a system for visual inspection of powder deposition and a
system for online and real-time monitoring of the melt pool. A combination of these two
systems enables to guarantee the quality of SLM parts with high confidence.",,,,,,
"['Tang, Shangyong', 'Wang, Guilan', 'Zhang, Haiou', 'Wang, Rui']",2021-11-04T18:25:17Z,2021-11-04T18:25:17Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89998', 'http://dx.doi.org/10.26153/16919']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['online surface defects detection system', 'surface defects', 'defect detection', 'deep learning', 'support vector', 'arc welding based additive manufacturing', 'AWAM']",An Online Surface Defects Detection System for AWAM Based on Deep Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a1a2938-334b-41e0-b163-e61cb6383e49/download,University of Texas at Austin,"Defects detecting layer by layer in arc welding based additive manufacturing (AWAM) is a
big challenge as it affects the successive layer quality of the products. Most of the work on layer
quality defection were focused on 3D profile measurement and X-ray spectroscopy method but it
is inefficient, expensive with poor adaptability. In this work, an online intelligent surface defects
detection system for AWAM was developed through deep learning algorithm and support vector
machine method. To achieve a reliable surface feature of the welding beads, a vision sensor was
used to get the image of the shaped surface synchronously. The system was trained offline and
online to acquire knowledge of the welding beads which were classified into five patterns as normal,
pore, hump, depression and undercut. An defection test result showed 95.29% accuracy. The
system was verified to be practical with high accuracy and efficiency for the surface defects.",,,,,,
"['Hartman, Aja', 'Baker, Mary', 'Tastl, Ingeborg', 'Nauka, Krzysztof']",2023-01-20T13:53:28Z,2023-01-20T13:53:28Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117253', 'http://dx.doi.org/10.26153/tsw/44134']",eng,2022 International Solid Freeform Fabrication Symposium,Open,MJF,Opacity Modulation in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24c1ba80-88c7-45af-ba3f-21ca98e02b35/download,,"HP’s powder-based technology, Multi Jet Fusion (MJF), uses a fusing agent to 
selectively melt polymer powder in a layer-by-layer fashion to create 3D parts. There are many 
applications that require variable opacity including signage, medical models, and backlit 
buttons and indicators on computers, vehicles, and instruments. The industry also needs to 
replicate different materials that have varying optical properties throughout their thickness, 
such as skin or tortoiseshell, and to enable techniques such as covert markings on parts. 
Although completely opaque parts are achievable by doping the base powder material with an 
opacifying material, this opacifying method makes the whole part opaque instead of allowing 
variability at a voxel level. By modulating both opacifying agent loading and the geometric 
design of the opaque part region in our MJF platform, we have achieved variable optical 
properties within parts, modulating optical transmission from 48 % to 1 %.",,,,,,
"['Carter, William', 'Tucker, Michael', 'Mahony, Michael', 'Toledano, David', 'Butler, Robert', 'Roychowdhury, Subhrajit', 'Nassar, Abdalla R.', 'Corbin, David J.', 'Benedict, Mark D.', 'Hicks, Adam S.']",2021-11-16T15:37:04Z,2021-11-16T15:37:04Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90316', 'http://dx.doi.org/10.26153/tsw/17237']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['open scan path', 'selective laser melting', 'acceleration of large-scale additive manufacturing', 'ALSAM', 'Air Force']",An Open-Architecture Multi-Laser Research Platform for Acceleration of Large-Scale Additive Manufacturing (ALSAM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/2005da82-0de6-4f58-a656-a8e98dbdc621/download,University of Texas at Austin,"As Selective Laser Melting (SLM) technology matures, researchers and engineers
responsible for transitioning the technology from rapid prototyping into manufacturing are gaining
a better understanding of the opportunities with this revolutionary technology. A step for
accelerating solutions is to allow researchers complete access to all aspects of the process for
experimentation. As part of an AFRL-sponsored program with America Makes, a production-grade SLM machine (a Concept Laser M2) will be enhanced to allow operation with either the
original OEM controls and scan path generation or an open-source set of software developed under
America Makes programs. This machine will be referred to as the ALSAM Platform and will be
delivered to the Air Force along with the source code for the open scan path generation software
(written in C++) and the open machine controller (written in LabVIEW™).",,,,,,
"['Elliott, A.M.', 'Love, L.J.']",2021-10-28T22:44:51Z,2021-10-28T22:44:51Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89722,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['metal additive manufacturing', 'operator burden', 'build cycle', 'part processing', 'reset']",Operator Burden in Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb250543-2d70-4dfd-8ebb-0d8f2bf5458d/download,University of Texas at Austin,"Additive manufacturing (AM) is an emerging manufacturing process that creates usable machine
parts via layer-by-layer joining of a stock material. With this layer-wise approach, high-performance geometries can be created which are impossible with traditional manufacturing
methods. Metal AM technology has the potential to significantly reduce the manufacturing
burden of developing custom hardware; however, a major consideration in choosing a metal AM
system is the required amount of operator involvement (i.e., operator burden) in the
manufacturing process. The operator burden not only determines the amount of operator training
and specialization required but also the usability of the system in a facility. As operators of
several metal AM processes, the Manufacturing Demonstration Facility (MDF) at Oak Ridge
National Labs is uniquely poised to provide insight into requirements for operator involvement
in each of the three major metal AM processes. The paper covers an overview of each of the
three metal AM technologies, focusing on the burden on the operator to complete the build cycle,
process the part for final use, and reset the AM equipment for future builds.",,,,,,
"['Foster, B.K.', 'Reutzel, E.W.', 'Nassar, A.R.', 'Hall, B.T.', 'Brown, S.W.', 'Dickman, C.J.']",2021-10-19T19:20:04Z,2021-10-19T19:20:04Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89328,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['powder bed fusion', 'additive manufacturing', 'layer-wise imaging']","Optical, Layerwise Monitoring of Powder Bed Fusion",Conference paper,https://repositories.lib.utexas.edu//bitstreams/f99366e0-828f-4a6c-b890-44313eecc83b/download,University of Texas at Austin,"In powder bed fusion additive manufacturing, pre-placed layers of powder are successively
fused to form three-dimensional components. During part build-up, flaws in the material or part
geometry can occur and lead to an unacceptable part quality. Common flaws include porosity, poor
surface finish, and thermal deformation. Here, a layer-wise imaging technique is presented for process
monitoring. The technique relies on collection and analyses of images taken under oblique
illuminations of fused and pre-placed powder layers. Results of three-dimensional reconstruction of
image data and identification of potential flaws are presented.",,,,,,
"['Ray, Phillip', 'Chahine, Gilbert', 'Smith, Pauline', 'Kovacevic, R.']",2021-10-05T14:48:34Z,2021-10-05T14:48:34Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88385', 'http://dx.doi.org/10.26153/tsw/15324']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['golf club head', 'electron beam melting (EBM)', 'additive manufacturing (AM)', 'functionally graded porosity (FGP)']",Optimal Design of a Golf Club using Functionally Graded Porosity,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dbbda56b-55e4-446a-bbf8-3da786ca64ae/download,University of Texas at Austin,"The current work portrays a new concept of designing and manufacturing golf club heads
with functionally graded porosity (FGP) by means of electron beam melting® (EBM®). In light
of the advancement of additive manufacturing (AM) technologies and the consequent wide
spread applications in the aerospace, automotive, and biomedical industries, the current work
discusses a new application in sport technologies; for example, in the golf industry. EBM®
makes it possible to print the designed porosity within a golf club head, to reduce the weight and
optimize performance. The focus is to design the golf club head with FGP to improve
performance and reduce weight. The dynamic properties of porous materials are investigated
theoretically. The porosity in the club head was analyzed numerically by simulating the impact
between the club head and a steel ball in order to determine the coefficient of restitution (COR)
of the club head. The simulation’s parameters are in compliance with the U.S Golf Association’s
(USGA) test procedure for measuring COR.",,,,,,
"['Cao, Xiaoqing', 'Ayalew, Beshah']",2021-10-18T21:53:03Z,2021-10-18T21:53:03Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89263,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser-aided powder deposition', 'melting interface tracking', 'optimization']",Optimal Melting Interface Tracking in Laser-Aided Powder Deposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9744852e-6c3b-4b92-a1ce-8c3b7c30e0e5/download,University of Texas at Austin,"This paper presents a systematic control inputs optimization method for melting interface
tracking in laser-aided powder deposition (LAPD) processes. Using a proposed interface
approximation and a coordinate system moving with the laser source, and adopting the enhanced
thermal conductivity method, the process model is first reduced to a set of coupled partial
differential equations (PDEs) in fixed spatial domains. Then, the control problem of achieving
process target properties is formulated as one of optimizing the control inputs to track a
prescribed melting interface which is approximated from required process target parameters.
This proposed optimization scheme is solved by the adjoint-based gradient method for which an
algorithm is provided. A weighting scheme is also proposed to overcome feasibility issues with
poor interface specifications and still achieve improved tracking of target parameters. The
proposed scheme is illustrated through a simulation-based case study on a laser cladding process.",,,,,,
"['Miyanaji, Hadi', 'Zhang, Shanshan', 'Lassell, Austin', 'Zandinejad, Amir Ali', 'Yang, Li']",2021-10-21T20:58:01Z,2021-10-21T20:58:01Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89446,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'binder jetting process', 'green parts', 'sintering']",Optimal Process Parameters for 3D Printing of Dental Porcelain Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2c89f960-629c-465b-93bd-136187cfdbbf/download,University of Texas at Austin,"Dental porcelain material is a typical glass ceramic material that is widely used in dental
restoration applications. However, there still exists limited knowledge about the fabrication of
this type of materials using binder jetting additive manufacturing process. There are several
important factors such as saturation level, power level, drying time as well as spread speed,
which would potentially affect the accuracy and strength of the printed parts before and after
sintering. Therefore, in this research an extensive experimental study was performed to obtain
the optimal process parameters for the dental porcelain materials fabricated via ExOne binder
jetting system. The results also provide general printing guidelines for the fabrication of glass
ceramic materials.",,,,,,
"['Dzogbewu, T.C.', 'Yadroitsev, I.', 'Krakhmalev, P.', 'Yadroitsava, I.', 'Du Plessis, A.']",2021-11-02T13:47:30Z,2021-11-02T13:47:30Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89801,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['process parameters', 'in situ', 'Ti15Mo', 'laser powder bed fusion']",Optimal Process Parameters for In Situ Alloyed Ti15Mo Structures by Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/629d91f2-8c81-4f4d-b117-734dc1762954/download,University of Texas at Austin,"Powder Bed Fusion (PBF) is a manufacturing method with the advantage that it can
produce objects of complex geometry. Additionally, it opens great opportunities to synthesize
new materials from elemental powder using an in situ alloying approach. Potential of the in situ
PBF alloying approach is nevertheless not well understood due to lack of experimental
knowledge and information on the influence of process parameters on the microstructure,
homogeneity and properties of the final materials. This investigation is focused on Ti15Mo alloy
that was chosen as a promising β-type alloy for biomedical applications due to low Young’s
modulus, close to the mechanical properties of bones. Geometrical characteristics of single tracks
were investigated at a wide range of laser powers and scanning speeds. Threshold of enthalpy
ratio to transition from conduction to keyhole mode was found. To study the distributions of
molybdenum in Ti matrix, X-ray nanoCT scans and SEM EDS were performed. Effects of hatch
distance and scanning strategy on the layer surface morphology were investigated.
Microstructure and mechanical properties of as-built specimens were analyzed. Illustrated effects
of each process parameter on the synthesized material is paramount to successful manufacturing
of advanced implants with mechanical properties close to bones.",,,,,,
"['Ghazanfari, Amir', 'Li, Wenbin', 'Leu, Ming C.', 'Landers, Robert G.']",2021-10-21T18:28:54Z,2021-10-21T18:28:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89420,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['rastering orientation', 'freeform extrusion fabrication', 'horizontal staircase effect']",Optimal Rastering Orientation in Freeform Extrusion Fabrication Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24ec35db-5e3f-4d69-a408-02e06324aca9/download,University of Texas at Austin,"Many researchers have tried to optimize the build direction of additively manufactured parts to minimize
the vertical staircase effect. However, the horizontal staircase effect should also be considered when fully dense
parts are to be fabricated. In this paper, part inaccuracy due to the horizontal staircase effect is considered in
order to determine the optimal rastering orientation in building the part. An algorithm is developed to estimate
this inaccuracy and a technique is proposed to minimize it. The effect of rastering orientation on staircase errors
is examined, and the particle swarm optimization method is used to determine the optimum rastering angle that
leads to minimum errors for each layer. Several case studies are considered where the staircase errors are
calculated with and without optimizing the rastering orientation. The results show that the errors can be reduced
considerably when using the optimal rastering orientation. To verify the analytical results, parts are fabricated
using a freeform extrusion fabrication process at various angles and the errors are compared.",,,,,,
"['Subedi, Subodh C.', 'Thoma, Dan J.', 'Suresh, Krishnan']",2023-01-26T15:34:53Z,2023-01-26T15:34:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117318', 'http://dx.doi.org/10.26153/tsw/44199']",eng,2022 International Solid Freeform Fabrication Symposium,Open,LPBF,Optimal Truss-Type Supports for Minimal Part Distortion in LPBF,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2390f25-2ad7-43a9-a743-ebc981c7cd24/download,,"Efficient transfer of heat to the build plate is important for part printability in laser
powder bed fusion (LPBF). Support structures provide pathways for heat dissipation from
the melt pool to the build plate. Truss-type supports have been proposed for better thermal
management in LPBF since they are easy to analyze, optimize and post-process. In this
paper, we consider thermo-elastic LBPF simulations, where a part and corresponding truss-
type support are progressively coupled during the build process. Transient thermal FEA
is performed as each layer is built to obtain temperature profiles. Thermal and structural
equivalent static loads are obtained from the transient results, which are accumulated to
compute aggregate structural equivalent static loads (ASESL). Structural deformation of
coupled systems involving part and truss-type supports is also computed after each layer-
wise built. Finally, cross-sectional areas of truss-type supports are optimized using ASESL
to minimize structural deformation. Optimized supports show a significant reduction in
part deformation compared to un-optimized supports. Numerical results are presented to
demonstrate the merits of the proposed method.",,,,,,
"['Vaithilingam, Jayasheelan', 'Laoboonmee, Kasidis', 'Saleh, Ehab', 'Hague, Richard J.M.', 'Wildman, Ricky D.', 'Tuck, Christopher J.']",2021-11-01T22:23:35Z,2021-11-01T22:23:35Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89780,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['substrate angles', 'dielectric substrate', 'multi-functional parts', 'multi-material parts', 'optimization', '3D inkjet printing']",Optimisation of Substrate Angles for Three Dimensional Inkjet Printing of Multi-Functional and Multi-Material Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a7e251e-b95c-40c9-b24a-0c57ceebd1e7/download,University of Texas at Austin,"Three dimensional (3D) inkjet printing of multiple materials is being explored widely to
fabricate multi-functional parts such as the printing of strain gauges and heating elements
embedded within a component. Although dielectrics and conductive materials can be inkjet-printed together, there is a difference in their layer thicknesses. Inkjet printed conductive
materials require sintering at temperatures of around 150°C to form a conductive network.
Exposing the dielectric materials which may be sensitive to prolonged heat exposure could
affect their material properties. Hence, optimisation of conductive routes within the structural
material is essential. It is envisaged that printing of structural materials at an angle to a certain
height/layers and then printing a few layers (~ 10 layers) of conductive material on to the top
surface will enable faster fabrication and reduced exposure of the dielectric material to heat.
To compliment this aim, in this study, dielectric substrates were printed at different angles and
the conductivity of the tracks were assessed. Surface morphology of the printed tracks showed
misplacement of droplets for angles above 15° due to the influence of print height. The printed
tracks remained conductive up to 65°; however above 50°, the tracks were highly resistive (>
150KΩ). The optimal angle to obtain conductive tracks with the highest print resolution was
15° and it was greatly influenced by the print height. Further study is required to optimise the
substrate angle by using a constant print height and varying the slope length.",,,,,,
"['Khodabakhshi, K.', 'Gilbert, M.', 'Dickens, P.', 'Hague, R.', 'Fathi, S.']",2021-09-28T17:49:28Z,2021-09-28T17:49:28Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88135', 'http://dx.doi.org/10.26153/tsw/15076']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['anionic polymerization', 'caprolactam', 'polyamide 6', 'inkjetting']",Optimised Polymerization Conditions for Inkjetting of Caprolactam to Produce Polyamide Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a86f31b0-fa1d-4623-b8a5-5af5b5a78939/download,University of Texas at Austin,"Rapid Manufacturing (RM) techniques have been developed to shorten the processing cycle, and 
lead to efficient production of ready-to-use complex items. This project aims to manufacture 
three dimensional parts, directly from monomer, using a 3D Printing process based on ink-jet 
printing technology. A fast polymerization and high monomer conversion are essential. This 
work describes conditions for the rapid anionic polymerization of caprolactam after inkjetting to 
produce polyamide (nylon 6) parts. The effect of polymerization temperature and different 
catalyst/initiator types and concentrations on the rate of reaction were studied. Results show that, 
although increasing polymerization temperature results in quicker polymerization, the highest 
polymerization rate is achievable with 0.38g of sodium hydride and 320µl of N-acetylcaprolactam.",,,,,,
"['ONUH, S.O.', 'HON, K.K.B.']",2018-12-07T16:13:27Z,2018-12-07T16:13:27Z,1997,Mechanical Engineering,doi:10.15781/T24747B9Z,http://hdl.handle.net/2152/71445,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['RPT', 'Stereolithography']",Optimising Build Parameters and Hatch Style for Part Accuracy in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4abe751-e6b1-4a58-b0d7-ae5d3952b577/download,,"A detailed study of the effects of layer thickness, hatch spacing, hatch overcure
depth, and hatch fill cure depth on the quality of the StereoLithography (SL) product was
carried out using acrylic based resin. Taguchi Method was used for analysing all
experimental results. The ANOVA and the Signal-to-noise ratio (SIN) results were used to
select the optimum parameters and the appropriate factor levels for further experiments. A
new hatch styIe with an optimum layer thickness is proposed for the build process with
minimum geometrical distortion.",,,,,,
"['Richards, I.P.F.', 'Garabet, T.M.N.', 'Bitar, I.S.', 'Salmon, F.M.']",2021-11-02T19:49:10Z,2021-11-02T19:49:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89881,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser sintering', 'desktop-laser sintering', 'thermoplastic polyurethane', 'powder characterisation', 'mechanical properties']",Optimising Thermoplastic Polyurethane for Desktop Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0ca12e4b-3034-4b84-922f-4c353a0f2388/download,University of Texas at Austin,"Laser Sintering (LS) is an industrially relevant Additive Manufacturing method that has
become more accessible since the introduction of commercially available desktop-LS systems.
However, useable materials are currently limited to several grades of nylon, and so the aim of
this study was to optimise an unknown, novel material for use in desktop-LS. A grade of
thermoplastic polyurethane (UNEXTPU) was analysed to determine thermal properties,
particle characteristics and bulk powder flow efficiency. To facilitate laser absorption at
445nm, a carbon additive (graphite) was added to UNEXTPU; the addition of graphite also
significantly improved flow efficiency. UNEXTPU was successfully processed on a desktop-LS system, and mechanical testing found that it possesses properties comparable to industrial
grade thermoplastic polyurethanes (Elongation at Break: 139%, Tensile Modulus: 48.7Mpa,
Ultimate Tensile Strength: 7.9Mpa, Shore Hardness: 75). Bulk powder flow efficiency and
mechanical properties were retained in twice recycled powder. This research has established a
new viable elastomeric material for use in desktop-LS.",,,,,,
"['Brackett, D.', 'Panesar, A.', 'Ashcroft, I.', 'Wildman, R.', 'Hague, R.']",2021-10-11T21:32:37Z,2021-10-11T21:32:37Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88650', 'http://dx.doi.org/10.26153/tsw/15584']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['multi-material 3D printing', 'additive manufacturing', 'topology optimization', 'design analysis', 'optimization', 'active internal systems']",An Optimization Based Design Framework for Multi-Functional 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97f045cd-b91f-4d18-8739-f5976cce77df/download,University of Texas at Austin,"This work investigates design analysis and optimization methods for the integration of
active internal systems into a component for manufacture using multi-material 3D printing
processes. This enables efficient design of optimal multifunctional components that exploit the
design freedoms of additive manufacturing (AM). The main contributions of this paper are in two
areas: 1) the automated placement and routing of electrical systems within the component volume
and, 2) the accommodation of the effect of this system integration on the structural response of
the part through structural topology optimization (TO). A novel voxel modeling approach was
used to facilitate design flexibility and to allow direct mapping to the 3D printer jetting nozzles.",,,,,,
"Levy, Richard A.",2018-05-03T17:59:57Z,2018-05-03T17:59:57Z,1993,Mechanical Engineering,doi:10.15781/T2M32NT3H,http://hdl.handle.net/2152/65048,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Craniofacial Imaging and Modeling', 'CT']",Optimization of 2D CT Data Sets for Three-Dimensional,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db47963a-4cf7-4a16-8c5e-9e0d301008d9/download,,"Computer-generated anatomic modeling using radiologic data is a well-known entity. Currently,
state of the art 3D modeling systems lack the variable thresholding, user interactive, capabilities of
3D imaging software.1 We investigated clinical parameters - cr scan plane, 2D filter algorithm,
surrounding medium - and tested a simple mathematical thresholding algorithm based upon
experimentation with a cr phantom, to evaluate a semiautomated approach to 3D craniofacial
imaging and model generation. (Figure 1)",,,,,,
"['Borstell, D.', 'Georg, M.-C.']",2021-12-01T21:27:43Z,2021-12-01T21:27:43Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90619', 'http://dx.doi.org/10.26153/tsw/17538']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['design for additive manufacturing', 'gear assembly', 'worm gear', 'double bass']",Optimization of a Worm Gear Assembly Design for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9144d42-e32f-45d5-a087-debdf15c8f55/download,University of Texas at Austin,"Worm gears are widely used to transmit power at predominantly low speeds and highspeed ratios. Their self-locking characteristic makes them unique to many drive applications.
Industrial power requirements are causing forces and tensions mostly prohibiting thermoplastic
materials in worm gear drive trains.
Double basses are tuned using a worm gear assembly made from machined steel and
brass or cast bronze. Neglectable power requirements, few hours of operation, esthetic
expectations and the classic luthier’s approach to making such an instrument by hand have
excluded the double basses’ tuning assembly from all engineering approaches regarding
optimal design, efficiency and costs.
Manufacturing the traditionally designed double bass worm gear assembly using
Additive manufacturing processes requires the application of general design rules and the rules
of Design for Additive Manufacturing (DFAM) resulting in an optimized gear assembly
regarding weight, costs and design properties.",,,,,,
"['Fieger, T.', 'Nugara, D.', 'Huebner, J.', 'Witt, G.']",2021-11-02T18:39:08Z,2021-11-02T18:39:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89864,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser sinitering', 'adhesives', 'bonding agent', 'assembly', 'norms and standards']",Optimization of Adhesively Joined Laser-Sintered Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5791c8b8-adf9-4b91-8154-ddf54097c0e5/download,University of Texas at Austin,"As additive manufacturing technologies are advancing in quality and economic
feasibility, joining and assembly is becoming increasingly important for industrial users. In this
study, the performance of four adhesives for polyamide 12 specimens is analyzed. Testing of
bonding relevant factors, such as the surface energy of the solid substrates, is conducted. Tensile
shear tests of plain polyamide 12 specimens glued together, show an early adhesive failure of
the joint. To increase the polar bonding forces and the surface energy of the solid substrate,
pretreatments such as atmospheric plasma, chemical, corona and flame treatment are applied.
An increase up to 81% of the original binding strength can be achieved with flame treatment.
As an alternative to increase the bonding strength of the joints, the effects of design changes of
the bonding area are looked at. The research shows that micro tubes on the surface of a substrate
can increase the bonding strength up to 49%. A summary of the impact of all pretreatments and
design changes is given and the suitability of each application is assessed.",,,,,,
"['Peng, Hao', 'Ghasri-Khouzani, Morteza', 'Gong, Shan', 'Attardo, Ross', 'Ostiguy, Pierre', 'Aboud Gatrell, Bernice', 'Budzinski, Joseph', 'Tomonto, Charles', 'Neidig, Joel', 'Shankar, M. Ravi', 'Billo, Richard', 'Go, David B.', 'Hoelzle, David']",2021-11-02T20:06:57Z,2021-11-02T20:06:57Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89883,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'DMLS', 'optimization', 'build orientation', 'thermal distortion', 'thermal stress', 'support structure']",Optimization of Build Orientation for Minimum Thermal Distortion in DMLS Metallic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c07b1f92-77de-4b5a-9108-ae96f86c8f7a/download,University of Texas at Austin,"The additive manufacturing (AM) process direct metal laser sintering (DMLS) can quickly
produce complex parts. However, thermal stress in DMLS may induce thermal distortion and cause
build failure. This manuscript presents an optimization algorithm for the build orientation in
DMLS to minimize thermal distortion. The algorithm is built on the foundation of two coupled
thermal and thermo-mechanical models developed in our previous work. The DIRECT search
method and a universal objective function for thermal distortion were used. Constraints were
included to rule out build orientations resulting in overheating or excessive oxidation. The
optimization algorithm was tested on a rectangular bar and a complex, contoured part. Both parts
were printed using an EOS M290 machine, and measured by a coordinate measuring machine. In
comparison to build orientations chosen by two novice operators, the optimized build orientations
gave significant reduction in the thermal distortion and number of print trials before print success.",,,,,,
"['Tariq, Usman', 'Joy, Ranjit', 'Wu, Sung-Heng', 'Arif Mahmood, Muhammad', 'Woodworth, Michael M.', 'Liou, Frank']",2024-03-26T20:06:25Z,2024-03-26T20:06:25Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124386', 'https://doi.org/10.26153/tsw/50994']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['metal additive manufacturing', 'finite element analysis', 'computational time', 'directed energy deposition', 'residual stress']",OPTIMIZATION OF COMPUTATIONAL TIME FOR DIGITAL TWIN DATABASE IN DIRECTED ENERGY DEPOSITION FOR RESIDUAL STRESSES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f998361-54b5-4584-ba7a-b2b6a0e703b3/download,University of Texas at Austin,"Metal Additive Manufacturing (MAM) has experienced rapid growth and demonstrated its cost-effectiveness
in the production of high-quality products. However, MAM processes introduce significant thermal gradients that
result in the formation of residual stresses and distortions in the final parts. Finite Element Analysis (FEA) is a
valuable tool for predicting residual stresses, but it requires substantial computational power. This study aims to
reduce computational time by incorporating a thermo-mechanical model specifically designed for the Directed
Energy Deposition (DED) process using Ti6Al4V. This model predicts the thermal history and subsequent
residual stresses in the deposited material. Various FEA methods, including “chunk”, layer, and conventional
methods are examined, providing a comparative analysis of computational cost and numerical accuracy. These
findings contribute towards the realization of a digital twin database, where the incorporation of efficient and
accurate FEA models can optimize part quality and strength while reducing computational time.",,,,,,
"['Chen, Yu', 'Vastola, Guglielmo', 'Zhang, Yong Wei']",2021-11-15T21:10:24Z,2021-11-15T21:10:24Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90273', 'http://dx.doi.org/10.26153/tsw/17194']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['inert gas flow', 'chamber', 'computational fluid dynamics', 'laser powder bed fusion', 'CFD', 'L-PBF']",Optimization of Inert Gas Flow Inside Laser Powder Bed Fusion Chamber with Computational Fluid Dynamics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d9152b01-255b-4d83-9888-a3e9ac9ef01e/download,University of Texas at Austin,"It is crucial to maintain a uniform and fast enough inert gas flow inside build chamber to obtain high-quality final products (e.g. low porosity) without oxidation. The current study investigated the behaviors of the
inert gas flow inside a chamber with CFD simulations, as well as its evaluation and optimization. The gas flow
pattern inside the chamber was evaluated in terms of the uniformity of velocity across the build plate. It was
shown that the gas channels and locations of inlet openings significantly affected the flow inside the chamber.
So the design of gas channels/inlets and flow rates was carefully adjusted to generate uniform gas flow across
the chamber to remove emissions from the melt pool efficiently. Furthermore, the re-circulation of emission
inside chamber was significantly reduced to keep the chamber walls clean and minimize the damage to the
optical surface. In conclusion, CFD benefits in improving quality of products and reducing life-cycle cost for
laser powder-bed fusion process (L-PBF).",,,,,,
"['Theeda, Sumanth', 'Ravichander, Bharath Bhushan', 'Jagdale, Shweta Hanmant', 'Kumar, Golden']",2023-03-28T19:24:34Z,2023-03-28T19:24:34Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117668', 'http://dx.doi.org/10.26153/tsw/44547']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser Powder Bed Fusion', 'neural networks', 'machine learning', 'SS316L']",Optimization of Laser Process Parameters Using Machine Learning Algorithms and Performance Comparison,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24687bb1-b94f-4e92-9fd1-ef48f53c8877/download,,"Laser powder bed fusion (L-PBF) can be used to produce near net-shaped functional metal 
components. Despite offering high flexibility in producing components with intricate geometries, 
L-PBF has many constraints in terms of controllability and repeatability because of large number 
of processing parameters. There is a need for a robust computational model which can predict the 
properties of L-PBF parts using a wide range of processing parameters. In this work, several 
Machine learning-based algorithms like Random Forest, k Nearest Neighbors, XGBOOST, 
Support Vector Machine (SVM), and Deep Neural Networks are used to model the property-
processing parameters relation for SS 316L samples prepared by LPBF. Laser power, scan speed, 
hatch spacing, scan strategy, volumetric energy density, and density are used as the input to these 
models. The developed model is then used to predict and analyze the surface roughness of as-
fabricated SS 316L specimens. The prediction and experimental results are compared for the 
above-mentioned models to evaluate the capabilities and accuracy of each model.",,,,,,
"['Theeda, S.', 'Ravichander, B.B.', 'Jagdale, S.H.', 'Kumar, G.']",2023-04-03T17:45:39Z,2023-04-03T17:45:39Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117729', 'http://dx.doi.org/10.26153/tsw/44608']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser Powder Bed Fusion', 'Neural Networks', 'Machine Learning', 'SS316L']",Optimization of Laser Process Parameters Using Machine Learning Algorithms and Performance Comparison,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9282689e-03f2-47da-abd5-30d5d236e787/download,,"Laser powder bed fusion (L-PBF) can be used to produce near net-shaped functional metal 
components. Despite offering high flexibility in producing components with intricate geometries, 
L-PBF has many constraints in terms of controllability and repeatability because of large number 
of processing parameters. There is a need for a robust computational model which can predict the 
properties of L-PBF parts using a wide range of processing parameters. In this work, several 
Machine learning-based algorithms like Random Forest, k Nearest Neighbors, XGBOOST, 
Support Vector Machine (SVM), and Deep Neural Networks are used to model the property-
processing parameters relation for SS 316L samples prepared by LPBF. Laser power, scan speed, 
hatch spacing, scan strategy, volumetric energy density, and density are used as the input to these 
models. The developed model is then used to predict and analyze the surface roughness of as-
fabricated SS 316L specimens. The prediction and experimental results are compared for the 
above-mentioned models to evaluate the capabilities and accuracy of each model.",,,,,,
"['Kim, Dong Sung', 'Thompson, Steven', 'Grunlan, Melissa', 'Tai, Bruce L.']",2021-10-28T14:57:02Z,2021-10-28T14:57:02Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89658,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['low one-photon polymerization', 'hydrostatic 3D printing', 'silicone material', 'optimization']",Optimization of Low One-Photon Polymerization for Hydrostatic 3D Printing of Silicone Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/261fca2d-e113-466a-b7e5-19015a5cf652/download,University of Texas at Austin,"This study investigated the parameter optimization of low one-photon polymerization in
hydrostatic 3D printing (H3P). H3P produces 3D structures in a hydrostatic condition with
minimum or no physical supports, used particularly for soft materials that typically require
substantial supports to hold the position and shape in conventional 3D printing methods. H3P
allows for “in-liquid” polymerization to happen by low one-photon polymerization (LOPP) to cure
the silicone at the focusing spot inside of the resin. With the selected UV-curable silicone, different
wavelengths, light intensities, and exposure times were investigated to achieve an ideal LOPP. The
ideal LOPP should have a wide time window to precisely control the polymerization size and
produce a consistent geometry. This is largely dependent on the light wavelength and then the
intensity. In this study, the wavelength of 387 nm with the absorbance rate of 0.008 was found the
optimal setting for the selected silicone among 365 nm (0.051 absorbance rate) and 405 nm (nearly
0 absorbance rate) wavelengths. The results showed that the parameters for LOPP are very
selective.",,,,,,
"['Yan, Jingyuan', 'Battiato, Ilenia', 'Fadel, Georges M.']",2021-10-18T21:47:41Z,2021-10-18T21:47:41Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89260,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Laser Engineered Net Shaping', 'Direct Metal Deposition', 'in-flight melting', 'multi-materials']",Optimization of Multi-Materials In-Flight Melting in Laser Engineered Net Shaping (LENS) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8eb1000e-65cf-422c-b12e-0b323e825808/download,University of Texas at Austin,"A heterogeneous object has potentially many advantages and in many cases can realize
appearance and/or functionality that homogeneous objects cannot achieve. LENSTM, a Direct
Metal Deposition process, is one technology with the potential to fabricate heterogeneous objects.
In-flight melting provides an advantageous condition for better mixing of multiple materials with
different properties, thus critical for fabricating heterogeneous objects. In this study, a multi-materials in-flight melting model of the LENS process is developed for the cases of single and
multiple particles jets. The impact of in-flight particles melting as well as substrate melting on
materials mixing is investigated. An optimization method is proposed for the LENS fabrication
of heterogeneous objects based on the concurrent melting of particles and substrate. A cermet
composite material fabrication test case is utilized to demonstrate the applicability of the method.
Inconel 718 powders and alumina ceramic powders are used as building materials in the test case.
A group of optimized process parameters are provided: using a 320 W, 600 μm spot diameter
laser moving at 10 mm/s, the injection angles are 20°, the injection velocities are 1 m/s, the
material feeding rates are 0.5 g/min, the particle diameters are 20 μm, and the nozzle diameters
are 0.7 mm for both materials. Moreover, the material with a lower melting point should be
injected in the front of the laser moving direction, while the material with a higher melting point
should be injected from the rear.",,,,,,
"['Yamauchi, Yuki', 'Kigure, Takashi', 'Niino, Toshiki']",2023-01-19T17:48:01Z,2023-01-19T17:48:01Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117251', 'http://dx.doi.org/10.26153/tsw/44132']",eng,2022 International Solid Freeform Fabrication Symposium,Open,adhesion,Optimization of penetration depth and powder layer thickness for proper  interlayer adhesion in polymer laser sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef8501fc-dc22-4f8e-a8c7-ac71fb111fba/download,,"In laser sintering, the melt pool depth relative to the powder layer thickness is the 
main factor influencing interlayer adhesion strength. The melt pool depth is closely 
related to the amount of laser energy and its penetration depth. Previous studies have 
shown that using a near-infrared laser and an additive agent that absorbs its light allows 
for a wide range of penetration depth control. This research focuses on the optimization 
of the powder layer thickness and penetration depth to achieve appropriate interlayer 
adhesion. To determine the optimal amount of laser energy, the relationship between 
the amount of laser energy and part density for each layer pitch and penetration depth 
was determined. The relationship between the amount of energy supplied normalized 
by the penetration depth and part density was consistent regardless of the penetration 
depth of the powder material. The adhesion strength of specimens prepared using 
different optimal amounts of energy to maximize part density was evaluated. Based on 
this evaluation, layer thickness normalized by penetration depth is the dominant factor 
influencing interlayer adhesion strength.",,,,,,
"['Karapatis, N.P.', 'Egger, G.', 'Gygax, P.E.', 'Glardon, R,']",2019-03-12T17:05:57Z,2019-03-12T17:05:57Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73604', 'http://dx.doi.org/10.26153/tsw/746']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'polymer']",Optimization of Powder Layer Density in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/badbcef3-9fa5-4b0a-bb38-34299dcaedae/download,,"An important parameter for the overall quality of SLS parts is the density of powder layers before sintering.
Previous studies have shownthatthe control of powder particle shape and size distribution can increase the density of
non-packed powder beds. However, these studies concerned beds several orders of magnitude larger than the SLS
layers. The purpose ofthis study. is to determine if,and to what extent, the density of thin powder layers can be
ineteased. Experiments show that the density of thin layers increases from 53% to 63% when adding 30% fine powder
to the coarse powder,/with a coarse-to-fine ratio of 1:10. Compared with the bulk experiments, this density
improvement method is less efficient, because the particles do not arrange as efficiently, and the wall effects can
become predominant.",,,,,,
"['Ashby, Kathryn', 'Fieldman, Zack', 'Kenney, Pat', 'Rockstroh, Todd']",2021-10-19T15:17:33Z,2021-10-19T15:17:33Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89295,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['direct metal laser melting', 'process parameters', 'reentrant build geometry', 'reentrant surface finish']",Optimization of Process Parameters for Reentrant Surfaces in Direct Metal Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e8f7e7b4-e6c6-40f1-95ad-fda053da2505/download,University of Texas at Austin,"One of the key factors for development and optimization of direct metal laser
melting (DMLM) is the analysis of process parameters on reentrant build geometry and
surface finish. Recent studies have focused on the optimization of standard build
parameters with only minor emphasis on reentrant geometries. Parameters that are not
optimized often contribute to poor surface finish, difficult to remove supports, and failed-to-build geometries of reentrant surfaces that limit the capabilities of DMLM. Through the
analysis of multiple studies with varying process parameters and input scan path
geometry, open loop methods for creation and control of reentrant build geometries are
assessed and presented.",,,,,,
"['Leu, Ming C.', 'Pattnaik, Shashwatashish', 'Hilmas, Gregory E.']",2021-09-30T18:34:38Z,2021-09-30T18:34:38Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88273', 'http://dx.doi.org/10.26153/tsw/15214']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'zirconium diboride parts', 'optimization', 'ultra-high temperature applications']",Optimization of Selective Laser Sintering Process for Fabrication of Zirconium Diboride Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6f45122-5955-458a-92e4-55635d7e62da/download,University of Texas at Austin,"Selective Laser Sintering (SLS) was investigated to fabricate Zirconium Diboride
(ZrB2) parts for ultra-high temperature applications. Experiments were conducted to
determine values of SLS process parameters (laser power, scan speed, line spacing, and
layer thickness) that can be used to build ZrB2 parts with high integrity and sharp
geometrical features. A sacrificial plate with a proper number of layers (determined from
experimentation) separated from the main part was built in order to reduce thermal
gradients when building the main part. The sacrificial plate was found to assist in
eliminating cracks in the bottom of the main part. The fabricated green parts then went
through post processing steps including binder burnout and sintering at proper
temperature schedules, to remove the binder and sinter the ZrB2 particles. The test bars
after sintering had an average relative density of 87% and an average flexural strength of
250 MPa.",,,,,,
"['Ghanekar, Amol S.', 'Crawford, Richard H.', 'Watson, Douglas']",2019-11-20T17:08:24Z,2019-11-20T17:08:24Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78485', 'http://dx.doi.org/10.26153/tsw/5570']",eng,2003 International Solid Freeform Fabrication Symposium,Open,SLS Process,Optimization of SLS Process Parameters Using D-Optimality,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2817d846-20ce-4633-8fd0-f4a55af79692/download,,"Solid Freeform Fabrication (SFF) refers to a group of processes that manufacture parts of
arbitrarily complex geometry without tooling. Currently, the operation of most SFF machines
requires skilled operators with expertise in choosing process parameters in ordered to achieve the
desired part quality. Thus, the “push-button 3D hardcopy” promise of SFF has yet to be realized.
This paper presents a framework for selecting optimal process parameter values automatically
for the selective laser sintering (SLS) process. The research described considered five process
parameters that are important for the SLS process. To achieve quality measures from the five
process parameters, optimization is inevitable. The method optimizes these process parameters
of SLS with respect to a set of desired quality measures, based on user input of the relative
importance of each of the quality measures. The basis for the framework is the so-called Doptimality criterion applied to a series of factorial experiments that capture empirically the
relationships between the process parameters and part quality measures. The framework is
implemented in MINITAB™ and a macro is used to perform the optimization.",,,,,,
"['Teufelhart, S.', 'Reinhart, G.']",2021-10-06T21:19:25Z,2021-10-06T21:19:25Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88447', 'http://dx.doi.org/10.26153/tsw/15384']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Additive Layer Manufacturing', 'lattice structures', 'strut diameters', 'stress directions']",Optimization of Strut Diameters in Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5f8f6d4e-22e9-44c1-b6ef-60a4dad3dfa7/download,University of Texas at Austin,"Additive manufactured lattice structures show a high potential for lightweight design.
Currently, these structures have a periodical build-up, which leads to disadvantageous stress
states. On the one hand, unfavorable bending loads on the single struts appear. This can be
avoided by an adaption of the course of the structure to the main stress directions inside the part.
On the other hand, different stress values are appearing inside the single struts. Therefore, a
procedure for the optimization of the struts diameters is presented. Thus, it becomes possible to
achieve equal stresses in the whole structure and gain a better lightweight performance.",,,,,,
"['Krol, T.A.', 'Zach, F.', 'Seidel, C.']",2021-10-06T21:15:54Z,2021-10-06T21:15:54Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88446', 'http://dx.doi.org/10.26153/tsw/15383']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['metal-based additive manufacturing', 'support structures', 'finite element models']",Optimization of Supports in Metal-Based Additive Manufacturing by Means of Finite Element Models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/668d7730-ab1b-4e54-87d4-0006d38fc64c/download,University of Texas at Austin,"Metal-based additive manufacturing processes require a supporting of overhanging part areas during the powder
solidification e. g. for improving the heat dissipation to the substrate. Technology users nowadays strive to
reduce support areas due to economical aspects, while simultaneously enhancing the process stability by
maximizing the support stiffness. For the simplification and acceleration of this support design procedure, the
presented work describes a methodology for optimizing support structures by means of finite element models.
Thereby, the main approaches are covering a fractal adaptation of the support layout and an optimization of
block supports depending on the calculation results. The presented methods were applied by using experimental
components.",,,,,,
"['Mukhametkaliyev, T.M.', 'Ferrucci, M.', 'Pavan, M.', 'Villanueva, M.C.', 'Craeghs, T.', 'Claeys, C.', 'Deckers, E.', 'Desmet, W.']",2021-11-30T20:14:33Z,2021-11-30T20:14:33Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90533', 'http://dx.doi.org/10.26153/tsw/17452']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'laser sintering', 'vibro-acoustic metamaterial', 'ED mapping', 'up-skin and down-skin scanning strategy', 'scan pattern', 'computer tomography', 'optimization']",Optimization of the Additive Manufacturing Process for Geometrically Complex Vibro-Acoustic Metamaterials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f0558a7-8fde-4be8-9b52-b4527ce51f1a/download,University of Texas at Austin,"A study performed at KU Leuven provided a proof-of-concept of vibro-acoustic locally
resonant meta-materials manufactured with Laser Sintering (LS). However, the geometry and
material properties of the manufactured parts deviated from their nominal (specified) values,
resulting in differences in resonant frequencies of the locally added resonators and a deviation from
their predicted vibro-acoustic performance. In this work, the fabrication of locally resonant vibroacoustic metamaterials was improved through a holistic engineering approach, resulting in an
improved vibro-acoustic performance. It is shown that unequal energy density distribution within
the printing layers is one of the main causes of deviations.",,,,,,
"['Brown-Moore, Tosh Kāneala', 'Balaji, Srivatsan', 'Lipton, Jeffrey']",2023-02-09T19:07:39Z,2023-02-09T19:07:39Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117444', 'http://dx.doi.org/10.26153/tsw/44325']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Ukraine,Optimizing 3D Printed Tourniquets for Immediate Aid in Ukraine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/51e4f486-b942-4886-867b-122164499057/download,,"The outbreak of conflict in Ukraine has been met with a drastic increase in demand for 
medical devices like the COVID pandemic. Additive manufacturing enables the on-demand onsite 
manufacturing of medical devices, such as tourniquets, necessary to save lives in emergency 
situations where delivery isn’t an option. Here we show the relative performance of open-source 
3D printed GLIA tourniquet components made from ABS and PETG and compare them to a 
commercially available combat application tourniquet (CAT). Using a variety of mechanical tests, 
our results demonstrate that tourniquet components printed with PETG are the best alternative to 
commercially available tourniquets in terms of cost and mechanical properties. We used this work 
to guide aid efforts for Ukraine through the Open-Source Medical Supply Organization.",,,,,,
"['Thompson, David C.', 'Crawford, Richard H.']",2018-11-08T15:05:17Z,2018-11-08T15:05:17Z,1995,Mechanical Engineering,doi:10.15781/T2MK65T8G,http://hdl.handle.net/2152/69882,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'SALD', 'Rapid prototyping']",Optimizing Part Quality with Orientation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f8062c8-0c2b-448c-b2fd-b6fcdcf560bb/download,,"The orientation of SFF-manufactured parts can have a significant effect on the
quality of the parts, in both surface effects and strength. Currently, orientation is
either ignored or set on the basis of experience. This paper takes some simple experiments
and creates quantitative measures relating different aspects of part quality to
orientation. This leads to several computational tools for optimizing the orientation
of a part for manufacture with SLS or SALD on the basis of part strength, surface
""aliasing"" error, volumetric supports, and build time as an alternative to human
experts.",,,,,,
"['Asiabanpour, B.', 'Vejandla, D.T.', 'Novoa, C.', 'Jimenez, J.', 'Fischer, R.']",2021-09-28T18:25:13Z,2021-09-28T18:25:13Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88146', 'http://dx.doi.org/10.26153/tsw/15087']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['plasma cutting', 'regression model', 'desirability function', 'optimiization', 'experimental design', 'Rapid Manufacturing']",Optimizing the Quality of Parts Manufactured by the Automated Plasma Cutting Process Using Response Surface Methodology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/010be919-80ed-41b8-8f9d-0c994df5e4e4/download,University of Texas at Austin,"Automated plasma cutting is an effective process for building complex two-dimensional metallic
parts in a short period of time. Because the plasma cutting machine has several factors or input
variables to control (e.g., current, cutting speed, torch height) and a variety of part quality
characteristics or response variables to satisfy (e.g., flatness, clean cut, bevel angle), it is very
difficult to find an overall optimum machine setting. In this research, response surface
methodology and desirability functions are used to simultaneously optimize 18 part quality
characteristics. Final results identify an optimal machine configuration that facilitates the
fabrication of parts with close-to-perfect quality for all responses considered.",,,,,,
"['Novoa, C.', 'Flores, A.']",2021-11-18T01:23:03Z,2021-11-18T01:23:03Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90391', 'http://dx.doi.org/10.26153/tsw/17312']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'AM', 'fused deposition modeling', 'FDM', 'polylactic acid', 'PLA', 'design of experiments', 'DOE']",Optimizing the Tensile Strength for 3D Printed PLA Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/197a26d4-fd9e-442d-89fa-f59e26d9121d/download,University of Texas at Austin,"This research investigates on how extruder nozzle temperature, model infill rate (i.e.
density) and number of shells affect the tensile strength of three-dimensional polylactic acid (PLA)
products manufactured with the fused deposition model technology. Our goal is to enhance the
quality of 3D printed products using the Makerbot Replicator. In the last thirty years, additive
manufacturing has been increasingly commercialized, therefore, it is critical to understand
properties of PLA products to broaden the use of 3D printing. We utilize a Universal Tensile
Machine and Quality Engineering to comprehend tensile strength characteristics of PLA. Tensile
strength tests are performed on PLA specimens to analyze their resistance to breakage. Statistical
analysis of the experimental data collected shows that extruder temperature and model infill rate
(i.e. density) affect tensile strength.",,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2023-01-19T17:34:45Z,2023-01-19T17:34:45Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117249', 'http://dx.doi.org/10.26153/tsw/44130']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Organizing Committee,Organizing Committee,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e33398a-5278-4648-ba8b-1550a38eb505/download,,,,,,,,
"['Borish, Michael', 'Roschli, Alex']",2021-12-06T23:43:59Z,2021-12-06T23:43:59Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90721', 'http://dx.doi.org/10.26153/tsw/17640']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['slicing', 'on-demand slicing', 'additive manufacturing', 'sensor feedback', 'modeling feedback']",ORNL Slicer 2.0: Towards a New Slicing Paradigm,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1bb4ab61-d089-43bc-ab12-f955bd574e5a/download,University of Texas at Austin,"One fundamental step of additive manufacturing is slicing. Slicing is the conversion of a 3D
mesh to a set of layers containing all the necessary pathing to construct the object. The slicing
process is typically viewed as one step in a sequential additive manufacturing workflow: an object is
designed in CAD, sliced, and subsequent G-code is sent to the additive manufacturing system for
construction. While successful, this workflow has limitations such as the utilization of sensor feedback
for pathing alteration. To address limitations and better take advantage of opportunities resulting from
the Industry 4.0 revolution, researchers at Oak Ridge National Laboratory developed a new slicer,
ORNL Slicer 2.0. Slicer 2.0 was developed with the concept of “on-demand” slicing whereby the
slicer takes a more active role in object construction. In this paper, we describe the fundamental
design philosophy of this new approach as well as the Slicer 2.0 framework.",,,,,,
"['Roschli, Alex', 'Messing, Andrew', 'Borish, Michael', 'Post, Brian K.', 'Love, Lonnie J.']",2021-11-02T20:32:16Z,2021-11-02T20:32:16Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89889,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['ORNL Slicer 2', 'ORNL Slicer', 'tool path', 'additive manufacturing']",ORNL Slicer 2: A Novel Approach for Additive Manufacturing Tool Path Planning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7031e942-8b88-4479-bcbb-b81b0c5001a5/download,University of Texas at Austin,"ORNL Slicer is the first software designed to generate machine instructions, or tool paths,
from CAD files for large-scale 3D printing of metals and polymers. The software was
revolutionary because it allowed for slicing of models reaching 20 feet long, generating millions
of lines of G-Code in seconds. The structure of the first ORNL Slicer had limitations in its
framework, which has led to the development of ORNL Slicer 2. In the second version of the
slicer, the process is modularized with individual layers being divided into regions, smarter infill
patterns, and traversals are generated based upon stress, thermal, and other models. The new
software has also been structured to allow for slicing and reslicing based on machine feedback
during the printing process.",,,,,,
"['Ahn, Dong-Gyu', 'Lee, Jun-Young', 'Yang, Dong-Yol']",2020-02-17T15:46:24Z,2020-02-17T15:46:24Z,8/30/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/80015', 'http://dx.doi.org/10.26153/tsw/7040']",eng,2004 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,Orthopedic Surgery Planning Based on the Integration of Reverse Engineering and Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2404280-26e6-447d-9d38-eff43de19f25/download,,"This paper describes orthopedic surgical planning based on the integration of RE and RP.
Using symmetrical characteristics of the human body, CAD data of the original bone without
damages for the injured extent are generated from a mirror transformation of undamaged bone
data for the uninjured extent. The physical model before the injury is manufactured from RP
apparatus. Surgical planning, such as the selection of the proper implant, pre-forming of the
implant, decision of fixation positions and incision sizes, etc., is determined by a physical
simulation using the physical model. In order to examine the applicability and efficiency of
surgical planning technology for orthopedics, various case studies, such as a proximal tibia
plateau fracture, a distal tibia comminuted fracture and an iliac wing fracture of pelvis, are
carried out. As a result of the examination, it has been shown that the orthopedic surgical
planning based on the integration of RE and RP is an efficient surgical tool.",,,,,,
"['Martínez-Magallanes, Mario', 'Cuan-Urquizo, Enrique', 'Ramirez-Cedillo, Erick', 'Roman-Flores, Armando']",2024-03-27T15:54:58Z,2024-03-27T15:54:58Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124493', 'https://doi.org/10.26153/tsw/51101']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['fractal mechanical metamaterials', 'out-of-plane', 'Hibert curve', 'conformabiity', 'additive manufacturing', 'LCD SLA']",OUT-OF-PLANE MECHANICAL PROPERTIES OF ADDITIVELY MANUFACTURED FRACTAL REINFORCED STRUCTURES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61770751-c527-4527-a60a-53735f1634d5/download,University of Texas at Austin,"Architected materials are an emergent kind of materials that gain their
physical properties from their rationally designed micro-structures. They
are normally conformed by regular unit-cells repetition, but other variations,
such as hierarchal, aperiodic, and graded arrangements have also been explored
as well. Here we propose an approach consisting of using fractal geometry to
control the mechanical response of the metamaterials. We designed a set of
11 different arrangements based on the self-filling Hilbert fractal, the set
consisted of 3 different iteration orders at 3 different matching relative
densities, and two other graded arrangements. The samples were fabricated
using a Micro-LCD 3D-printer and tested under out-of-plane loads. The test was
performed using a texturometer with a spherical probe impregnated with red paint to
characterize the conformability of the samples. Force and
displacement were recorded to compare the mechanical response of the samples
against the fractal parameters and obtain the structure-property relation.",,,,,,
"['Li, Dian', 'Liu, Ruikai', 'Zhao, Xiayun']",2021-11-18T18:43:02Z,2021-11-18T18:43:02Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90463', 'http://dx.doi.org/10.26153/tsw/17384']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['temperature measurement', 'in-situ', 'metallic additive manufacturing']",Overview of In-Situ Temperature Measurement for Metallic Additive Manufacturing: How and then What,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f34616d6-cf12-4b65-ac1f-188b68a0d35a/download,University of Texas at Austin,"Additive manufacturing (AM) is important in industrial and economical domains but still
lacking process accuracy. In-situ measurement and process control can offer an effective solution.
In AM based on metals, the temperature field of melting pool has critical impacts on phase transformation and mechanical properties. Researchers have developed various approaches to track
real-time temperature during ultrahigh temperature in AM. Nevertheless, large temperature gradient around the energy source demands a capable measurement system and method due to the
limitations of the conventional infrared cameras and pyrometers. This study will explore the deficiency and improvement of the existing approaches with a focus on the cutting-edge methods of
AM process temperature measurement, along with a critical thinking about the follow-up usage of
the collected data. Specifically, it will report the status and trends in employing various machine
learning and advanced control techniques with the in-situ sensor data for process qualification
purposes.",,,,,,
"Rosen, David W.",2019-12-05T16:56:51Z,2019-12-05T16:56:51Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78646', 'http://dx.doi.org/10.26153/tsw/5702']",eng,2004 International Solid Freeform Fabrication Symposium,Open,WTEC Additive/Subtractive,Overview of the WTEC Additive/Subtractive Manufacturing Study of European Research,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1848110b-0f6d-4425-9193-f12cecc633a4/download,,"As a follow-up to the 1996 JTEC/WTEC study of rapid prototyping research in Europe and
Japan, the 2003 Additive/Subtractive Manufacturing study assessed the evolution of RP
technologies and new developments in the area. The goal of this study was to gather information
on the worldwide status and trends in additive/subtractive (A/S) manufacturing science and
technology and disseminate it to government decision makers and the research community. This
talk will present the primary observations, results, and conclusions of the study. Highlights
include: The European Union has an organized effort to make advances in A/S manufacturing,
the levels of activity and infrastructure are superior to the US, and European countries have
targeted rapid manufacturing - the science and technology of production manufacture using A/S
technologies. The talk also provides the context for subsequent presentations in the Session on
European SFF Programs.",,,,,,
"['Ma, Changyu', 'Lin, Yu-Keng', 'Zheng, Tianqi', 'Mallory, Phillip', 'Zhu, Jianhao', 'Morris Wang, Y.', 'Li, Xiaochun', 'Kang, Bruce', 'Li, Bingbing']",2024-03-26T16:44:48Z,2024-03-26T16:44:48Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124367', 'https://doi.org/10.26153/tsw/50975']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['ODS SS316L', 'Y2O3', 'additive manufacturing', 'grain refinement']",Oxide Dispersion Strengthened (ODS) SS316L Prepared by Laser Powder Bed Fusion (L-PBF): Analysis of Microstructure and Hardness Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/121ab036-66e0-4bd9-a6a8-37bba7dfbfd2/download,University of Texas at Austin,"In this paper, dense oxide dispersion-strengthened (ODS) SS316L with 0.5 wt.% Y2O3 was
fabricated using nano-Y2O3-embedded spherical SS316L powder via laser powder bed fusion (LPBF). The molten pool, oxide dispersion, cellular structure, and microhardness of the as-printed
ODS SS316L were investigated through optical microscopy (OM), scanning electron microscopy
(SEM), energy dispersive X-Ray Spectroscopy (EDX), and Vickers hardness testing, respectively.
The results reveal a uniform dispersion of Y-rich nanoparticles in as-printed ODS SS316L,
contributing to the development of a fine-grain structure in the as-printed ODS SS316L. A wide
and shallow molten pool was observed in as-printed ODS SS316L, and enhanced microhardness
was observed in ODS SS316L compared to pristine SS316L. The effects of Y2O3 on microstructure
evolution and reinforcing mechanisms of microhardness are discussed.",,,,,,
"['Wang, Xiangpang', 'Haiou, Zhang', 'Guilan, Wang']",2021-10-11T22:28:32Z,2021-10-11T22:28:32Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88669', 'http://dx.doi.org/10.26153/tsw/15603']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['complicated cavity part', 'discrete Voronoi diagram', 'distance map', 'path planning', 'additive manufacturing']",Parallel Contour Path Planning for Complicated Cavity Part Fabrication using Voronoi-based Distance Map,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9691d893-782a-4260-8b64-c7591ed7f7cd/download,University of Texas at Austin,"To generate parallel contour path for direct production of complicated cavity
component, a novel path planning based on Voronoi-based distance map is presented
in this paper. Firstly, the grid representation of polygonal slice is produced by
hierarchical rasterization using graphics hardware acceleration and divided into
Voronoi cells of contour by an exact EDT (Euclidean distance transformation). Then,
each VCI (Voronoi cell of inner contour) is further subdivided into CLRI (closed loop
region of inner contour) and OLRI (open loop region of inner contour). Closed paths
for each CLRI and the block merging VCO (Voronoi cell of outer contour) and all
OLRIs are generated by local and global isoline extraction, respectively. The final
path ordered in circumferential and radial directions is obtained by sorting and
connecting all individual paths. In comparison with conventional methods such as
pair-wise intersection and Voronoi diagram, the proposed algorithm is numerically
robust, can avoid null path and self-intersection because of the application of distance
map and discrete Voronoi diagram. It is especially used for FGM (Functionally
Graded Material) design and fabrication.",,,,,,
"['Kirschman, C.F.', 'Jara-Almonte, C.C.']",2018-04-18T17:41:00Z,2018-04-18T17:41:00Z,1992,Mechanical Engineering,doi:10.15781/T2NS0MF5K,http://hdl.handle.net/2152/64365,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Mechanical Engineering Department', 'Center for Advanced Manufacturing', 'CAD system']",A Parallel Slicing Algorithm for Solid Freeform Fabrication Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/444fb9f6-cf03-4c32-bba3-bf77599fe7f7/download,,"Slicing can accountfor more than 60% ofthe time to prepare apartforbuildingon astereolithographic apparatus. To improve the preparation time, aparallel slicing algorithm was developed. The algorithm was run on aButterfly GP1000 using 2,4,8, 16, and 32processors and superlinear speedup was observed due to high memory requirements. The parallel algorithm can reduce slice times by up to 92% on 16 concurrentprocessors as compared to a single processor.",,,,,,
"['Kumar, Kannan Suresh', 'Sparks, Todd E.', 'Liou, Frank']",2021-10-21T17:04:00Z,2021-10-21T17:04:00Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89407,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'wire feed', 'wire feed additive manufacturing', 'process parameters']",Parameter Determination and Experimental Validation of a Wire Feed Additive Manufacturing Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6f65c6f-aeef-4a16-ba68-368e888be11e/download,University of Texas at Austin,"Laser metal deposition with wire feed is one of the additive manufacturing methods with great
scope and robustness. Process parameters plays an important role in controlling the process and
obtaining an ideal manufactured part. Simulations tools are highly essential in determining the
ideal parameters and melt pool conditions. The current work is a transient 3D model of wire feed
additive manufacturing which realizes the heat transfer and fluid flow behavior of the process
with varying laser power and power density. The model was programmed in Python and a 1 KW
Gaussian beam fiber laser was used to conduct experiments. The effect of laser exposure to the
scanned and deposited profile on Ti-6Al-4V alloy is obtained. The comparison of simulation and
experimental results shows that this model can successfully predict the temperature profile, and
solidified metal profile. The optimum input parameters based on material properties can be
identified using the model.",,,,,,
"['Zhao, Xiayun', 'Rosen, David W.']",2021-10-21T18:21:04Z,2021-10-21T18:21:04Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89418,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Exposure Controlled Projection Lithography', 'interferometric curing monitoring', 'sensor model', 'calibration model']",Parameter Estimation Based Real-Time Metrology for Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e5f2bcf1-9d33-4c88-b7a9-79b1b25a021d/download,University of Texas at Austin,"Exposure Controlled Projection Lithography (ECPL) is a layerless mask-projection
stereolithography process, in which parts are fabricated from photopolymers on a stationary
transparent substrate. To enable advanced closed-loop control for ECPL, an in-situ
interferometric curing monitoring (ICM) system has been developed to infer the output of cured
height. However, the existing ICM method based on an implicit model and rough phase counting
is not fast and accurate enough. This paper reports on a new ICM method to address the
modeling and algorithms issues confronted by the current ICM method. The new ICM model
includes two sub-models: a sensor model of instantaneous frequency based on interference optics
and a calibration model. To solve the models, a moving horizon exponentially weighted online
parameter estimation algorithm and numerical integration are adopted. As a preliminary
validation, offline analysis of interferograms acquired in an ECPL curing experiment is
presented. The agreement between ICM estimated cured height and ex-situ microscope
measurement indicates that the overall scheme of the new ICM measurement method with a
well-established model, evolutionary estimation and incremental accumulation, is promising as a
real-time metrology system for ECPL. The new ICM method is also shown to be able to measure
multiple voxel heights consistently and simultaneously, which is desired in global measurement
and control of ECPL.",,,,,,
"['Zhu, Wei', 'Yan, Chunze', 'Yang, Jiayi', 'Wen, Shifeng', 'Shi, Yusheng']",2021-10-21T14:50:35Z,2021-10-21T14:50:35Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89384,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['carbon fiber', 'epoxy resin', 'selective laser sintering', 'processing parameters', 'thermoplastics']",Parameter Optimization for Preparing Carbon Fiber/Epoxy Composites by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/37106114-f8dc-4414-bcaf-66ad7d22f5c6/download,University of Texas at Austin,"Carbon fiber (CF) reinforced thermosetting resin composites offer a wide range
of high performance features including excellent strength, modulus and thermal
resistance and light weight. Consequently, they are increasingly demanded by
aerospace and automotive industries due to the tighter requirements of the transport
vehicles for lightweight as well as higher payloads. Although thermoplastics and their
composites have been widely used in additive manufacturing (AM), to date it is
difficult to manufacture carbon fibers reinforced thermosetting composite parts via
AM technologies. Therefore, this study developed a novel method based on selective
laser sintering (SLS) to fabricate high-performance carbon fiber/epoxy resin
composites. The response surface method was employed to study the processing
parameters affecting the quality of final parts, and an optimized processing condition
was obtained.",,,,,,
"['Deng, Xioaming', 'Zong, Guisheng', 'Beaman, Joseph J.']",2018-04-19T16:42:03Z,2018-04-19T16:42:03Z,1992,Mechanical Engineering,doi:10.15781/T2G15TT9P,http://hdl.handle.net/2152/64382,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Department of Mechanical Engineering', 'SLS']",Parametric Analysis for Selective Laser Sintering of a Sample Polymer System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b26e605b-13a0-4c84-8ecb-273ea3391661/download,,,,,,,,
"['Kyriazis, N.', 'Eine, J.', 'Thakur, A.R.']",2024-03-26T21:33:56Z,2024-03-26T21:33:56Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124420', 'https://doi.org/10.26153/tsw/51028']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'deposition pressure', 'freeform', 'multiaxis']",PARAMETRIC ANALYSIS OF DEPOSITION PRESSURE CONTROLLED MULTI-AXIS FREEFORM FABRICATION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d222319e-a46c-4d5c-8e93-e5b7c5f8bd35/download,University of Texas at Austin,"Additive manufacturing is being explored as one of the most promising in-space manufacturing techniques.
The presence of micro-gravity enables the fabrication of support-free sparse structures with ease. Sparse lattice
structures (e.g. trusses) are attractive for space applications as they can be tailored for specific load paths. Previous
studies have identified a positive correlation between deposition pressure and inter-layer adhesion in 3D printing.
However, excessive deposition pressures negatively influence the in-orbit printing accuracy. Therefore, a
parametric investigation was conducted to determine the optimal deposition pressure to fabricate mechanically
sound trusses in orbit. Support-free arches with varying nodal deposition pressures were 3D printed using a multiaxis robotic manipulator with integrated force sensors. Mechanical testing of these arches concluded that the
strength improvement plateaus and registers no significant increase in (joint) strength after a certain deposition
pressure, characterized by the properties of the extrude. Integration of a force-feedback facilitates free-form
printing of complex, multi-layered, support-free structures in terrestrial environments. In a free-floating space
environment, it assists in optimizing the overall printing process.",,,,,,
"['Martin Sun, Ming-shen', 'Beaman, Joseph J.', 'Barlow, Joel W.']",2018-04-10T19:28:33Z,2018-04-10T19:28:33Z,1990,Mechanical Engineering,doi:10.15781/T2JM23Z8N,http://hdl.handle.net/2152/64251,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['SSL', ""Frenkel's sintering model"", 'manufacturing process']",Parametric Analysis of the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/18e532ea-e5f6-4d63-a422-0719d115eaac/download,,"Qualitative and quantitative analyses are required to develop Selective Laser
Sintering into a viable Manufacturing process. A simplified mathematical model for
sintering incorporating the heat tJ;ansfer equation. and the sintering rate equation, but using
temperature independent thermal properties, is presented in this paper. A practical result is
the calculation of sintering depthdeftned as the depth of powder where the void fraction is
less than 0.1 as a function of control parameters, such as the laser power intensity, the laser
scanning velocity, and the initial bedtemperature. We derive the general behavior of laser
sintering. A comparison of model predictions with laser sinterlng tests is provided.",,,,,,
"['Fadel, Georges', 'Ganti, Ravi']",2019-02-20T17:13:54Z,2019-02-20T17:13:54Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73453', 'http://dx.doi.org/10.26153/tsw/605']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Controller', 'galvanometers']",Parametric Based Controller for Rapid Prototyping Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/519fe92e-9e9d-45bd-921f-3092450ec0b3/download,,"A methodology aiming at reproducing in Rapid Prototyping applications, exact parametric
curves from CAD data is presented. The approach consists of converting the space-based parametric
curves from the CAD system into time-base, such that the equations of the curve in terms of time are
then fed to a controller directly. Optimization is used to solve the problem, which has both Rapid
Prototyping process and scanning constraints. With information such as the equation of the curve, its
first and second derivatives with respect to time, a real-time trajectory controller can be designed.
The trajectory displays an increase in accuracy over traditional approaches using STL files, which is
ofthe order of the chordal tolerance used to generate tessellations. The system model involves
electrical and mechanical dynamics of the galvanometers and sensors. The controller, which acts on
two mirrors, deflecting the laser beam of a stereolithography machine in the x and y directions
respectively, should be easily substituted for current systems. Application of the methodology to
freeform curves shows acceptable tracking and can be improved by judicious selection ofthe equation
representing the spatial parameter as a function of time.",,,,,,
"['Chen, Kenwei', 'Crawford, Richard H.', 'Beaman, Joseph J.']",2018-11-16T16:27:27Z,2018-11-16T16:27:27Z,1996,Mechanical Engineering,doi:10.15781/T25D8P10H,http://hdl.handle.net/2152/70295,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'tracking control algorithm', 'SLC']",Parametric Representation of Part Contours in SLS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6cf4b306-1a7d-4e40-bf2e-f3075ecdb121/download,,"Current layer-based SFF technologies process faceted geometric input data to produce
polygonal contours of the part's boundary in each layer. However, for improved part quality,
other more accurate representations of part contours are desirable. Likewise, implementation of
Wu's minimum time optimal laser tracking control method for selective laser sintering (SLS)
requires contour curves that exhibit higher order continuity. In this paper, we first analyze the
requirements of optimal laser tracking to develop evaluation criteria for choosing a contour
representation. Several possible representation methods are reviewed. We show that the NonUniform
Rational B-Spline (NURBS) curve meets the criteria. A demonstration program
illustrates the advantages of NURBS curves for representing contours with uniform point
distributions. The results can be used in other control areas where uniform point distribution or
constant velocity is required.",,,,,,
"['Zhang, Yizhuo', 'Chou, Y. Kevin']",2020-03-02T14:39:55Z,2020-03-02T14:39:55Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80128', 'http://dx.doi.org/10.26153/tsw/7149']",eng,2006 International Solid Freeform Fabrication Symposium,Open,fused deposition modeling,A Parametric Study of Part Distortions in FDM Using 3D FEA,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7f0b328d-4e09-405d-beba-604c1424b486/download,,"We developed a finite element model to simulate the fused deposition modeling (FDM)
process. The model considers the coupled thermal and mechanical analysis and incorporates the
element activation function to mimic the additive nature of FDM. Due to repetitive heating and
cooling in the FDM process, residual stresses accumulate inside the part during the deposition.
The model is also used to evaluate the part distortions, revealing distortion features such as
vaulting shapes and distortion-core shifting. A parametric study, three factors and three levels,
was performed to evaluate the effects of the deposition parameters on residual stresses and part
distortions. Prototype models with larger sizes were fabricated, measured, and compared with the
simulations.
The simulation results show that (1) the scan speed is the most significant factor to part
distortions, followed by the layer thickness, (2) the road width alone is insignificant, however,
the interaction between the road width and the layer thickness is significant too, and (3) there are
other two-way and three-way interactions that are of secondary significance. Residual stresses
increase with the layer thickness, and increase with the road width, to a less extent though, yet
largely affected by the layer thickness. The FDM part distortions from the experiment show a
similar trend as in the simulations, but no quantitative correlation.",,,,,,
"['Sun, Dongwei', 'Li, Xuxiao', 'Tan, Wenda']",2021-11-02T15:19:57Z,2021-11-02T15:19:57Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89827,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'stainless steel 316L', 'deposition track morphology', 'grain structure']",A Parametric Study on Grain Structure in Selective Laser Melting Process for Stainless Steel 316L,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b54ac663-cb33-4715-af7b-4374910b3691/download,University of Texas at Austin,"Laser Selective Melting (SLM) process is used in this work to produce 3-dimensional samples
of Stainless Steel (SS) 316L. The effects of laser power, scanning speed, and laser scanning
strategy on the track morphology and grain structure are investigated. As the laser heat input is
increased by increasing laser power and/or decreasing laser scanning speed, the surface
morphology of the SLM track will vary according to the extent of powder melting, and the grain
size will increase correspondingly. Different laser scanning strategies can produce different grain
patterns, and a noticeable porosity can be found if the scanning strategy is not appropriate. The
grains in the bottom layers of the built samples inherit the crystallographic orientations from the
substrate through epitaxial growth; nucleation takes places in the top layers and introduces new
grains of random crystallographic orientations into the built samples.",,,,,,
"['Pridham, M.S.', 'Thomson, G.']",2018-05-03T17:05:54Z,2018-05-03T17:05:54Z,1993,Mechanical Engineering,doi:10.15781/T2N29PQ55,http://hdl.handle.net/2152/65040,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Applied Physics and Electronic and Manufacturing Engineering', '3-D welding', 'rapid prototyping', 'BRITE']",Part Fabrication Using Laser Machining and Welding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f2f2b584-cf7c-4c19-851d-c1b3c532095a/download,,"This paper describes the current work on a laser cutting and welding system for
the fabrication of prototype parts in mild and .. stainless steels. The relationship
to other rapid prototyping systems and to laminated tool production techniques is
discussed, the progress to date is described. Difficulties with current welding
procedures are outlined and alternative joining techniques are considered.",,,,,,
"['Yardimci, M. Atif', 'Guceri, Selcuk I.', 'Agarwala, Mukesh', 'Danforth, Stephen C.']",2018-11-16T15:21:38Z,2018-11-16T15:21:38Z,1996,Mechanical Engineering,doi:10.15781/T26D5PX1T,http://hdl.handle.net/2152/70287,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition', 'thermoplastic materials', 'process analysis']",Part Quality Prediction Tools for Fused Deposition Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5228d33e-69e8-4fdd-bc91-4d0a2f085526/download,,"Fused Deposition process fabricates requested part geometries by sequentially depositing
discrete curvilinear beads ofmaterial next to and on top of each other. The part integrity
depends strongly on the bonding quality at the bead interfaces. Since diffusion bonding of
thermoplastic components in the material system is thermally driven, temperature history
ofinterfaces determine the bonding quality. Detailed thermal analysis of deposition region
and layer building simulation for a model geometry have been performed to investigate
local and global material behavior during processing. A simple transport property
prediction model has also been developed for the determination of thermal transport
properties of the particle loaded systems used in Fused Deposition. Based on the
information obtained from thermal models, a computationally efficient part building
model has been developed to predict bonding quality in the whole part. The model is
driven by the same command file, sml file, that drives the Fused Deposition hardware;
and hence is capable of replicating the building process. The model has been tested for a
model geometry, spur gear, and three dimensional bonding quality distribution has been
predicted for the part.",,,,,,
"['Zhang, Xinchang', 'Liou, Frank']",2021-11-16T16:29:21Z,2021-11-16T16:29:21Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90336', 'http://dx.doi.org/10.26153/tsw/17257']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['remanufacturing', 'hybrid processing', 'direct laser deposition', 'component repair']",Part Remanufacturing Using Hybrid Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/15782a05-d435-4112-835b-a219ce208600/download,University of Texas at Austin,"Many users of high-performance metal parts, such as the aerospace industry, the mold/die
casting industry, and heavy machinery consumers, extend the service of these damaged parts by
employing remanufacturing technology. Additive manufacturing has unique capabilities, such as
low heat input, a small heat-affected zone, free-form fabrication, and a near-net-shape. This paper
summarizes the effort and the tested results to achieve an automated remanufacturing process using
hybrid additive manufacturing and CNC machining processes. It will enable the robust
remanufacturing-on-demand to significantly increase operational availability to reduce
sustainment costs, thus will lead to robust and quality remanufacturing that is critical for
remanufacturing process qualification.",,,,,,
"['Eiamsa-ard, Kunnayut', 'Nair, Hari Janardanan', 'Ren, Lan', 'Ruan, Jianzhong', 'Sparks, Todd', 'Liou, Frank W.']",2020-02-24T15:12:39Z,2020-02-24T15:12:39Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80079', 'http://dx.doi.org/10.26153/tsw/7100']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Gas Tungsten Arc Welding,Part Repair using a Hybrid Manufacturing System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ca2d785e-91d6-476b-b017-d49f48daf254/download,,"Nowadays, part repair technology is gaining more interest from military and industries
due to the benefit of cost reducing as well as time and energy saving. Traditionally, part
repair is done in the repair department using welding process. The limitations of the
traditional welding process are becoming more and more noticeable when the accuracy
and reliability are required. Part repair process has been developed utilizing a hybrid
manufacturing system, in which the laser aided deposition and CNC cutting processes are
integrated. Part repair software is developed in order to facilitate the users. The system
and the software elevate the repair process to the next level, in which the accuracy,
reliability, and efficiency can be achieved. The concept of repair process is presented in
this paper. Verification and experimental results are also discussed.",,,,,,
"['Grose, J.', 'Liao, A.', 'Tasnim, F.', 'Foong, C.S.', 'Cullinan, M.A.']",2024-03-26T20:08:29Z,2024-03-26T20:08:29Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124387', 'https://doi.org/10.26153/tsw/50995']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['microscale selective laser sintering', 'heat zones', 'additive manufacturing']",PART SCALE SIMULATION OF HEAT AFFECTED ZONES FOR PARAMETER OPTIMIZATION IN A MICROSCALE SELECTIVE LASER SINTERING SYSTEM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19f30244-c06c-40a1-b18a-9c1c76fb04e1/download,University of Texas at Austin,"The Microscale Selective Laser Sintering (μ-SLS) system can produce feature sizes on the
order of a single micrometer, far smaller than existing metal additive technologies. Despite this
advantage, there are challenges in producing reliable small-scale parts due to unwanted heat
transfer in the nanoparticle bed. To address this issue, a multiscale Finite Element thermal model
has been developed to predict the temperature changes that occur during sintering within the
particle bed. Nanoscale particle models are used to quantify material property changes experienced
by particle groups that undergo laser sintering. This work processes the property relationships
developed by the particle models and integrates comprehensive property functions into the partscale model to capture the nuanced thermal evolution that occurs during sintering. The multiscale
model predicts the extent of heat spread and part formation during sintering to optimize input laser
parameters, reduce unwanted heat spread, and improve the minimum feature resolution of
printable parts.",,,,,,
"['Peng, Hao', 'Go, David B.', 'Billo, Rick', 'Gong, Shan', 'Ravi Shankar, M.', 'Aboud Gatrell, Bernice', 'Budzinski, Joseph', 'Ostiguy, Pierre', 'Attardo, Ross', 'Tomonto, Charles', 'Neidig, Joel', 'Hoelzle, David']",2021-10-26T19:15:12Z,2021-10-26T19:15:12Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89561,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'DMLS', 'thermal distortion', 'thermal stress', 'part orientation', 'support structure', 'quasi-static loading']",Part-Scale Model for Fast Prediction of Thermal Distortion in DMLS Additive Manufacturing Part 2: A Quasi-Static Thermomechanical Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/851e07fe-5648-437b-82de-7db495fdb7ba/download,University of Texas at Austin,"The direct metal laser sintering (DMLS) additive manufacturing process can quickly
produce complex parts with excellent mechanical properties. However, thermal stress accumulated
in the layer-by-layer build cycles of DMLS may induce part distortion and even cause the failure
of the whole build process. This paper is the second part of two companion papers that present a
part-scale model for fast prediction of temperature history and part distortion in DMLS. In this
paper, a quasi-static thermomechanical (QTM) model is built to estimate the thermal distortion of
entire parts in DMLS. Firstly, the thermal contraction in each build cycle is modeled as a quasi-static loading process; the final thermal stress accumulated in the parts is the superposition of
thermal stress generated in each build cycle. Secondly, the stress relaxation process after the parts
are cut off from the substrate is modeled, and final distortion of the parts is predicted with thermal
stress calculated from the thermal contraction processes. In comparison to existing transient
thermomechanical models, the QTM can predict thermal distortion in DMLS with much faster
computational speed, and a comparison against experiment shows less than 10% error.",,,,,,
"['Johnston, Scott', 'Anderson, Rhonda', 'Storti, Duane']",2019-11-21T18:25:31Z,2019-11-21T18:25:31Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78558', 'http://dx.doi.org/10.26153/tsw/5614']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Steel Components,Particle Size Influence Upon Sintered Induced Strains Within 3DP� Stainless Steel Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fff2f6b-f754-4851-83ba-d93f5abbaa7e/download,,"Three-dimensional printing (3DP™
1
) is a layer-by-layer manufacturing process whereby a
three-dimensional (3D) component is created by the distribution of a liquid binder onto a powder
media. A 3DP™ process using stainless steel powder as its printing media requires post-printing
thermal processing for debinding and sintering of the printed green component. To minimize
dimensional distortion while increasing structural integrity of the green component, 3DP™
thermal post-processing is designed to produce only neck growth between particles, defined as
initial stage sintering.
The accepted theoretical model governing initial stage sintering strain for spherical powder
particles provides a qualitative account of strain development with respect to time and
temperature variance; however, the model does not produce an accurate quantitative account for
the magnitude of the strain when compared to dimensional experimental results. The theoretical
model indicates that powder particle size is the dominant parameter governing sintering strain.
The purpose of this study is to introduce an effective particle size into the theoretical model,
thus enabling the application of the theoretical model to estimate dimensional change for
components produced by 3DP™. Dimensional sintering experimentation has been performed
using 3DP™ test specimens with spherical powder particles having mean diameters of 20 Pm, 80
Pm, and 200 Pm. Experimental results and progress on the theoretical model are discussed.","Financial support for this work is provided by the Office of Naval Research, Contract
#N00014-C-00-0378.",,,,,
"['Sellers, R.', 'Gould, B.', 'Wolff, S.']",2021-12-06T23:17:52Z,2021-12-06T23:17:52Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90713', 'http://dx.doi.org/10.26153/tsw/17632']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'directed energy deposition', 'Ti-6Al-4V', 'x-ray imaging', 'thermal imaging', 'molybdenum', 'surface energy']",Particle-Melt Pool Interactions in Multi-Material Laser Based Directed Energy Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ec057e63-1558-4e2d-a9ec-ffa02f738b85/download,University of Texas at Austin,"Laser based metal directed energy deposition (DED) is an additive manufacturing process
that is currently on the rise in the industry. However, there is still a knowledge gap in the
understanding of fundamental interactions between particles and the melt pool in the DED
process and how to change the parameters to alter microstructure. This work utilized
synchronized in-situ thermal and X-ray imaging to understand the anomalous behavior of
molybdenum powder binding onto a Ti-6Al-4V substrate as fundamental understanding for
layer-by-layer processing. Using these visual techniques, particle velocity, mass, surface energy,
kinetic energy, contact area, and temperature were observed and calculated. The correlation is
shown and recorded to understand the wettability of particles and why some will bounce off of
the substrate while others enter the melt pool. This work will allow for the manipulation of
particle-melt pool interactions in DED which will help reproduce and build better parts more
efficiently",,,,,,
"['Moser, D.', 'Cullinan, M.', 'Murthy, J.']",2021-10-26T18:42:10Z,2021-10-26T18:42:10Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89553,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['melt modeling', 'selective laser melting', 'discrete element model', 'powder particles']",Particle-Scale Melt Modeling of the Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85151f2f-d375-4bb0-842e-3d13f94b88c5/download,University of Texas at Austin,"In this work, a melting model is developed and implemented to simulate the melting of
powder particles for Selective Laser Melting (SLS). A hybrid continuum-discrete methodology is
used to model the melting process. A Discrete Element Model (DEM) is used to generate random
packing structures of spherical particles. These structures are then placed on top of a background
mesh in the OpenFOAM finite volume library. The radiation transport equation (RTE) is solved
on the mesh to simulate the effect of laser heating. Heat sources generated by the RTE are
introduced into the energy equation, which is also solved on the mesh. Once particle melting
occurs, the resulting flow is solved for on the mesh. Computation of properties in the mesh cells
is accomplished using volume averaging between the solid, liquid, and background gas phases.
The resulting total melt pool depth and width is calculated and results compared against
previously published experimental results and good agreement is obtained. Relations are then
developed for the melt fraction of the powder as a function of the average temperature of the
powder. These relations can be used as bulk properties in the enthalpy model for part-scale
simulations.",,,,,,
"['Narahara, Hiroyuki', 'Kawaguchi, Shinichiro', 'Suzuki, Hiroshi']",2019-10-23T15:03:35Z,2019-10-23T15:03:35Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76753', 'http://dx.doi.org/10.26153/tsw/3842']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Stereolithography,Parts Design and Manufacturing Process Support System Based on Stereolithography Manufacturing Knowledge Database,Conference paper,https://repositories.lib.utexas.edu//bitstreams/20b73d3a-8a66-41ce-8b1c-6016905470b1/download,,"Although rapid prototyping technology has a strong point that complex parts can be
manufactured easily, it is difficult to satisfy further higher precision if designer isn't familiar with
the technological know-how of the manufacture. This research aims to develop a design support
system for realizing higher precision of RP easily in consideration of manufacturing know-how.
The function of this system is as follows: the knowledge of manufacturing know-how such as the
preferred manufacturing direction for higher precision is stored in database. The complex shape
of solid form is analyzed in the middle of design stage, and then preferred manufacturing
processes or compositions are advised by this system.",,,,,,
"['Chen, Xi', 'Zhang, Haiou', 'Hu, Jiannan', 'Xiao, Yu']",2021-11-18T18:18:38Z,2021-11-18T18:18:38Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90454', 'http://dx.doi.org/10.26153/tsw/17375']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['infrared thermography', 'stack temperature field', 'pixel width curve', 'defect detection', 'wire arc additive manufacturing']",A Passive On-Line Defect Detection Method for Wire and Arc Additive Manufacturing Based on Infrared Thermography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/789b20d5-44ce-486c-8899-859e72bff663/download,University of Texas at Austin,"According to the additive manufacturing process, this paper comes up with a passive
infrared thermography non-destructive testing method based on the stack temperature field and
pixel width curve. The temperature field of the arc-melting layer is collected in real-time, and
the multi-frame temperature data stream is stacked for maximum value, and the region where
the maximum value is greater than 800 °C is intercepted to obtain the current molten layer
profile. The AlexNet model is used to classify the profile of molten layers, such as normal,
deviation, flow and hump. Determine whether the current layer has a shape defect based on the
model and the pixel width curve and the processing such as milling and repair welding will be
taken in time. This method detects in real-time during the manufacturing process which will
cause irreversible losses, and the current layer detection information is also the basis for
adjusting the processing parameters of the next layer and realizes the closed-loop feedback of
the additive manufacturing process.",,,,,,
"['Geuy, Michael', 'Martin, Jay', 'Simpson, Timothy', 'Meisel, Nicholas']",2024-03-26T20:10:36Z,2024-03-26T20:10:36Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124388', 'https://doi.org/10.26153/tsw/50996']",en_US,2022 International Solid Freeform Fabrication Symposium,Open,"['robotic material extrusion', 'non-planar', 'additive manufacturing']",PATH PLANNING FOR NON-PLANAR ROBOTIC ADDITIVE MANUFACTURING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b76e63c0-fb07-46a6-980f-28c5b3965e90/download,University of Texas at Austin,"As material extrusion additive manufacturing continues to mature, there is increasing need for an
extrusion path planning (“slicing”) method that takes full advantage of the abilities of manydegree-of-freedom systems like those used in Robotic Material Extrusion (RoMEX). These
systems can create engineering parts with complex geometries and improved mechanical
properties by utilizing non-planar curved layers, part-region-specific extrusion parameters, and
support-free printing. This paper explores the application of 3D surfaces (demonstrated here with
an upward pointing cone) as the basis of non-planar layer generation without the need to
decompose the object into regions. Creation of these toolpaths incorporates key principles from
planar, multi-planar, and active-Z path generation methods with attention paid to variable layer
thickness, extrusion angle control, and overhang angle. The primary result of this work is a method
for the generation of curved extrusion paths forming layers of arbitrary shape for arbitrary part
geometry, based on a novel combination of existing best practices present throughout the available
literature.",,,,,,
"['Frank, Matthew C.', 'Joshi, Ashish', 'Anderson, Donald D.', 'Thomas, Thaddeus P.', 'Rudert, M. James', 'Tochigi, Yuki', 'Marsh, J. Lawrence', 'Brown, Thomas D.']",2021-10-01T00:28:23Z,2021-10-01T00:28:23Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88309', 'http://dx.doi.org/10.26153/tsw/15250']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['rapid machining', 'rapid prototyping', 'bone implants', 'surface texturing']",Patient-Specific Bone Implants using Subtractive Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5dcf002c-7b7d-4e7e-8fe1-8eb5d1442222/download,,"This research involves the development of rapid manufacturing for patient-specific bone implants
using a Subtractive Rapid Prototyping process. The geometry of segmental defects in bone, resulting
from traumatic injury or cancerous tumor resection, can be reverse-engineered from medical images (such
as CT scans), and then accurate defect fillers can be automatically generated in advanced synthetic or
otherwise bioactive/biocompatible materials. This paper presents a general process planning
methodology that begins with CT imaging and results in the automatic generation of process plans for a
subtractive RP system. This work uniquely enables the rapid manufacturing of implant fillers with
several key characteristics including; suitable bio-compatible materials and custom surface characteristics
on specified patches of the filler geometry. This work utilizes a PLY input file, instead of the more
common STL, since color texture information can be utilized for advanced process planning depending
on whether the surface is fracture, periosteal or articular in origin. The future impact of this work is the
ability to create accurate filler geometries that improve initial fixation strength and stability through
accurate mating geometry, fixation planning and inter-surface roughness conditions.
Keywords: Rapid Machining, Rapid Prototyping, Bone Implants, Surface Texturing",,,,,,
"['Himmer, T.', 'Stiles, E.', 'Techel, A.', 'Beyer, E.']",2020-02-20T19:37:32Z,2020-02-20T19:37:32Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80042,eng,2005 International Solid Freeform Fabrication Symposium,Open,Precise Cast Prototyping,PCPro a Novel Technology for Rapid Prototyping and Rapid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5973798d-595a-4c02-bb1c-d470d020c73d/download,,"PCPro stands for Precise Cast Prototyping, which is a combination of casting technologies and
milling. This method was developed at Fraunhofer IWS in Dresden, Germany. It is patented in
Germany [1] and is applied in the USA under US 10/794,936. The main goal for this
development was to shorten the process chain for making plastic prototypes accompanied by
higher quality. The casting technology was integrated in a machining center in order to enable a
high degree of automation and to avoid an external casting system. This means that Rapid
Manufacturing can be easily implemented using such an automated combination of casting and
machining.
This article describes the PCPro method by means of the fabrication of sample parts. The
advantages and the limitations in comparison to common Rapid Prototyping and Rapid
Manufacturing process chains will be discussed. In addition, the manufacturing of a prototype
machine is presented.",,,,,,
"['Luo, M.', 'Tian, X.', 'Shang, J.', 'Zhu, W.', 'Li, D.']",2021-11-11T15:33:23Z,2021-11-11T15:33:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90221', 'http://dx.doi.org/10.26153/tsw/17142']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['PEEK', 'interlaminar shear strength', 'crystallinity', 'laser device', 'heat treatment', 'in-situ', 'fused deposition modeling']",PEEK High Performance Fused Deposition Modeling Manufacturing with Laser In-Situ Heat Treatment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97730456-cd5c-4b4d-986d-2fb757658379/download,University of Texas at Austin,"Because of the thermal resistance, high mechanical properties, biocompatibility, PEEK have increasingly
extended their application in medicals, aircraft, industrial fields and so on. In FDM, a low crystallinity can be got
to limit volume contraction to avoid weak interlaminar bonding, which results in the conflict between high
interlaminar bonding and crystallinity. In this study, a CO2 laser device was adopted to improve both the
interlaminar shear strength and the crystallinity of PEEK part synchronously in FDM. A series of test was then
successively implemented. And after the observation and the analysis of the results, an obvious improvement was
got that its interlaminar shear strength could improve over 45%, while its crystallinity could improve over double
times for PEEK. Additionally, the process suggests a much potential in developing the gradient distribution of
the crystallinity or stiffness in multi-function integration manufacturing for PEEK-like semi-crystalline materials.",,,,,,
"['Seppälä, J.', 'Rockel, D.', 'Hupfer, A.']",2021-10-18T20:08:46Z,2021-10-18T20:08:46Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89226,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'design method', 'aircraft engine', 'aircraft engine components']",Performance and Functionality Based Design Methods for Improved and Novel Aircraft Engine Components for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a11931a-e8d3-4eea-a9a8-9a2d9cd9d995/download,University of Texas at Austin,"For aircraft engine manufacturers the technology of AM appears promising. AM provides
the opportunity for a highly flexible and a cost effective part production. Furthermore AM offers
new potentials and possibilities for lightweight designs. The implementation and applications of
AM can be divided in three different strategic application levels. The first level includes
manufacturing simple existing parts; these kinds of parts are already in production. In the second
level, new design tools, such as structural optimization, are used to improve an existing part by
benefiting from the new design freedom but without changing its functionality. The third level
includes novel parts with new functionality.
This paper presents design methods for AM parts for the second and third level:
performance and solution based approach, respectively. Also the safety classification of engine
parts is looked into. Step-by-step design methods are presented, accompanied by case studies that
demonstrate improvement to the initial design: a light weight, topology optimized turbine guide
vane (level two) and an aircraft engine casing design that has an improved tip clearance behavior
under transient operating cycles (level three).",,,,,,
"['Lane, B.', 'Grantham, S.', 'Yeung, H.', 'Zarobila, C.', 'Fox, J.']",2021-11-03T21:54:08Z,2021-11-03T21:54:08Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89944,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['process monitoring', 'sensors', 'metrology testbed', 'additive manufacturing', 'National Institute Standards and Technology', 'NIST']",Performance Characterization of Process Monitoring Sensors on the NIST Additive Manufacturing Metrology Testbed,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7fc4b220-4e14-477d-b545-6fd3da83b43c/download,University of Texas at Austin,"Researchers and equipment manufacturers are developing in-situ process monitoring techniques
with the goal of qualifying additive manufacturing (AM) parts during a build, thereby accelerating the
certification process. Co-axial melt pool monitoring (MPM) is one of the primary in-situ process
monitoring methods implemented on laser powder bed fusion (LPBF) machines. A co-axial MPM system
is incorporated on the Additive Manufacturing Metrology Testbed (AMMT) at the National Institute of
Standards and Technology (NIST); a custom LPBF and thermophysical property research platform where
one of many research goals is to advance measurement science of AM process monitoring. This paper
presents the methods used to calibrate and characterize the spatial resolution of the melt pool monitoring
instrumentation on the AMMT. Results from the measurements are compared to real melt pool images,
and analysis is provided comparing the effect on spatial resolution limits on image analysis.",,,,,,
"['Bitragunta, Venkata Sivaram', 'Sparks, Todd', 'Liou, Frank']",2021-10-20T20:19:39Z,2021-10-20T20:19:39Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89352,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['blown direct metal deposition process', 'perturbation frequency', 'disk feeders', 'deposit quality', 'surface roughness']",Performance Metric for Powder Feeder Systems in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a4134f18-1bc5-49ca-a375-e1803860f1b7/download,University of Texas at Austin,,,This paper describes experiments that were carried out to determine the significance between measured surface roughness values of the deposits over theoretically calculated performance metric values.,,,,
"['Jarrett, David O.', 'Gibert, James M.', 'Fadel, Georges M.']",2021-10-05T19:55:21Z,2021-10-05T19:55:21Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88421', 'http://dx.doi.org/10.26153/tsw/15360']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic additive manufacturing', 'metal matrix composites', 'steel wire reinforcements', 'aluminum matrix']",Performance of Stainless Steel AlSi 304 Wire Reinforced Metal Matrix Composites Made Using Ultrasonic Additive Manufacturing in Bending,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bfcc0cbf-c171-48a7-a69f-35e85859ade3/download,University of Texas at Austin,"Ultrasonic additive manufacturing (UAM) is a solid-state additive and subtractive
manufacturing process that utilizes ultrasonic energy to produce layered metallic parts.
The process is easily extended to create advanced multi-material structures, e.g., metal
matrix composites, functionally graded metallic components, and shape memory alloys.
This research utilizes a three point bending test to compare the elastic modulus in metal
matrix composites (MMC’s) specimens consisting of stainless steel wire reinforcements
with an aluminum matrix to unreinforced test specimens; both specimens are produced by
UAM. In the MMC the volume fraction of wire is relatively low, 0.77%, yet yields an
average increase in modulus of 8.9%.",,,,,,
"['Yuan, Xiao', 'Zhang, Jing', 'Zahiri, Behnam', 'Khoshnevis, Behrokh']",2021-11-01T22:05:21Z,2021-11-01T22:05:21Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89773,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['contour crafting', 'additive manufacturing', 'sulfur concrete', 'space colonization']",Performance of Sulfur Concrete in Planetary Applications of Contour Crafting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68a911f7-14a9-4638-9444-fb0fea81bbe1/download,University of Texas at Austin,"Sulfur concrete is a high potential composite material which meets NASA’s ISRU (In-Situ Resource Utilization) requirements for some Lunar and most Martian structure construction
by means of Contour Crafting (CC). The performance of sulfur concrete is sensitive to its
ingredients and to the variables in the thermal process used for applying the material. The sulfur
concrete extrusion process is implemented on a mini-scale auger extruder and a novel full-scale
extruder. An experiment is designed to study the factors that influence the workability of sulfur
concrete. The research result may be instrumental for improving the workability of sulfur
concrete, which also has significant terrestrial applications.",,,,,,
"['Marchal, V.', 'Peryaut, F.', 'Zhang, Y.', 'Labed, N.']",2021-12-07T17:47:46Z,2021-12-07T17:47:46Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90734', 'http://dx.doi.org/10.26153/tsw/17653']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['continuous fiber printing', 'periodic homogenization', 'elastic properties']",A Periodic Homogenization Model Including Porosity to Predict Elastic Properties of 3D-Printed Continuous Carbon Fiber-Reinforced Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b65890f-e579-4801-bbe5-a0f17124286d/download,University of Texas at Austin,"Adding continuous carbon fiber into the Fused Filament Fabrication (FFF) process is critical to get reinforced composite structures with improved mechanical properties. However, it
remains difficult for the designer to create optimized complex composite structures. Indeed,
performing numerical simulations on these materials require to know their elastic coefficients,
which are difficult to determine. Using a model of periodic homogenization which considers
both the fiber content and the porosity, would be a quick solution to predict the mechanical
properties of the printed composite. Based on material studies and validated mechanical tests,
this simulation model allows the use of a homogeneous material to replace the composite material for the finite element analysis. This will greatly reduce the number of elements required
in the model, leading to a big decrease of the computation cost. Hence, the numerical model
has potential to perform simulation-driven design processes, such as generative design.",,,,,,
"['Shigueoka, M.O.', 'de M. Junqueira, S.L.', 'Alves, T.A.', 'Volpato, N.']",2021-11-30T21:37:01Z,2021-11-30T21:37:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90557', 'http://dx.doi.org/10.26153/tsw/17476']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['porous media', 'permeability', 'material extrusion']",Permeability Analysis of Polymeric Porous Media Obtained by Material Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d9686b1b-9e1c-45ed-85d2-14360a3d9a7d/download,University of Texas at Austin,"Porous media (PM) are used in many applications, and their geometry and hydraulic properties are
essential in flow analysis, especially in geology (oil and gas) and medical (tissue engineering)
applications. Additive Manufacturing (AM) enables the production of planned porosity and the
material extrusion AM allows working with process parameters to produce lattice type geometries,
without the need to have a 3D model of the internal porous structure. This work presents a
preliminary study on the permeability of some PM designs obtained in PLA using an in-house
process-planning software. Two main filling variations of the raster strategies were studied, one
considering the displacement of staggered layers and the other involving a new joined filaments
proposal. The permeability obtained experimentally is compared with numerical outputs. The
results indicate that both filling strategies influence the PM permeability, but this was more
significant with the joined filaments approach.",,,,,,
"['Yardimci, M. Atif', 'Guceri, Selcuk I', 'Danforth, Stephen C.']",2018-10-10T15:50:28Z,2018-10-10T15:50:28Z,1995,Mechanical Engineering,doi:10.15781/T2NV99W2B,http://hdl.handle.net/2152/68757,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'stereolithography', 'laser-based methods']",A Phenomenological Numerical Model For Fused Deposition Processing of Particle Filled Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11db4dba-a999-4e4c-9eb9-fa2a30d6ad37/download,,"Fused Deposition ModelingTM utilizes the simple idea of melting, extrusion and
resolidification of thermoplastic filaments. The introduction of particulate materials,
especially ceramics and metals, will widen the range of capabilities of the process. The
present study is directed to the development of a family of numerical models for the
FDM and Fused Deposition of Ceramics processes. These models in turn would help to
predict the operation windows of the FDM/FDC. Time-dependent mesh generation and
parameter file generation are incorporated into the developed two-dimensional model.
Finite element method is used in order to address heat transfer issues regarding the
solidification ofthe thermoplastic binder",,,,,,
"['Steinchen, W.', 'Kramer, B.', 'Kupfer, G.']",2018-11-02T13:53:40Z,2018-11-02T13:53:40Z,1995,Mechanical Engineering,doi:10.15781/T2Z02ZV09,http://hdl.handle.net/2152/69327,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'photoelastic', '3D Systems']",Photoelastic Investigation Using New STL-Resins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/41508cf2-e773-46dc-a1c0-b0fd47b5d9b2/download,,"Stereolithography is not only ideal to study the function and the design of a simple or complex
component, but also for stress and strain analysis by means of photoelasticity. The basis for using
Stereolithograpy components is the biremngent property of the photoPOIYffiers, which has been
discovered in 1991 in the Lab ofPhotoelasticity and Holography [5]. Therefore, a few acrylate and epoxy
resins develoPed by Ciba-Geigy were calibrated and compared with the most commonly used resin,
Araldite B (manufactured by Ciba-Geigy, too). The experience shows that static and dynamic
photoelastic investigations by using the new STL-resins are possible. The time saving for photoelastic
investigations amountsto values about 10 months and the cost saving is equivalent to 90010.",,,,,,
"['Kim, Young Hyun', 'Lim, Jong Seon', 'Lee, In Hwan', 'Kim, Ho-Chan']",2021-09-29T17:08:09Z,2021-09-29T17:08:09Z,2009,Mechanical Engineering,,"['https://hdl.handle.net/2152/88190', 'http://dx.doi.org/10.26153/tsw/15131']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['photopolymer solidification', 'stereolithography process', 'laser exposure conditions']",Photopolymer Solidification for Inclined Laser Exposure Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/768b557a-5ded-4a09-aded-aff72b5fdc38/download,University of Texas at Austin,"It has been reported that the photopolymer solidification in the stereolithogrpahy process is
mainly depended on the laser exposure conditions such as laser power and scanning speed.
However, they were focused on the vertical laser exposure conditions. In this research, we
developed a mathematical model for the photopolymer solidification under the inclined laser
beam exposure condition. Using the developed mathematical model, the photopolymer
solidifications were simulated for various inclined laser exposure conditions. Developed
mathematical model was in good agreement with the experimental result. This research can be
applied to improve the surface roughness in the stereolithogrpahy process.",,,,,,
"['Chartoff, Richard P.', 'Du, Jin']",2018-11-02T16:30:30Z,2018-11-02T16:30:30Z,1995,Mechanical Engineering,doi:10.15781/T2NG4HB5D,http://hdl.handle.net/2152/69337,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['UV laser beam', 'SLA process', 'stereolithography resins']",Photopolymerization Reaction Rates By Reflectance Real Time Infrared Spectroscopy: Application To Stereolithography Resins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc98602e-3357-48c2-96c3-7232419a8769/download,,"An advanced real time infrared technique for studying the isothermal in-situ cure
of ultra-fast photopolymerization reactions has been developed. The method, referred to
as reflectance real time infrared (RRTIR), involves time resolved IR analysis by reflected
IR radiation while a resin sample is being exposed to a UV laser beam. The effect of
factors such as chemical composition, radiation intensity, and temperature on reaction
rate were determined for multifunctional acrylate resins exposed to a HeCd laser (325
nm). Isothermal cure profiles were monitored quantitatively through disappearance of the
810 cm-1
acrylate IR absorbance band. The dark reaction after the UV radiation was
turned off also was monitored. The RRTIR method is shown to be highly effective for
quantifying photopolymerization reactions in the millisecond time range.
The rate data indicate that quantitative comparisons between reactivities and
conversions for different stereolithography resins are possible using this method under
conditions that simulate the SLA process. Also, the data show conclusively that the
reaction continues for long periods of time after initial laser exposure. This is expected to
be a significant factor in the development of warpage and curl during the SLA building
process.",,,,,,
"['Olubummo, Adekunle', 'Zhao, Lihua', 'Hartman, Aja', 'Tom, Howard', 'Zhao, Yan', 'Wycoff, Kyle']",2024-03-25T22:29:25Z,2024-03-25T22:29:25Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124322', 'https://doi.org/10.26153/tsw/50930']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['nickel dithiolene', '3D printing', 'bleaching', 'additive manufacturing']",Photothermal Bleaching of Nickel Dithiolene for Bright Multi-colored 3D Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/889a6490-9196-488f-96bd-8c61f249ceb7/download,University of Texas at Austin,"HP’s Multi Jet Fusion is a powder bed fusion 3D printing technology that utilizes a carbon-based radiation absorber
in combination with a near infrared (NIR) light source to facilitate the fusion of polymer powder in a layer-by-layer
fashion to generate 3D parts. Most available carbon-based and NIR radiation absorbers have an intrinsic dark color,
which as a result will only produce black/gray and dark colored parts. However, there are many applications that
require variable color, including prosthetics, medical models, and indicators, among others. To create white, bright
colored, and translucent parts with MJF, a visibly transparent and colorless radiation absorber is required. In this
paper, we designed an activating fusing agent (AFA) that contains a red, strong NIR absorbing dye that turns colorless
after harvesting irradiation energy during the MJF 3D printing process and provide a bright colored part when working
with other color agents.",,,,,,
"['Hong, Zhen', 'Wang, Zhiping', 'Deng, Sihao', 'Zhang, Yicha', 'Bernard, Alain']",2021-12-06T23:30:01Z,2021-12-06T23:30:01Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90717', 'http://dx.doi.org/10.26153/tsw/17636']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['toolpath optimization', 'profile-based sweep', 'hybrid additive manufacturing', 'HAM']",Physical Deposition Profile Based Toolpath Generation and Optimization for Additive Volume Building in Hybrid Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d6e54ab1-a349-4cd1-bf1c-50d5bcbb2bf5/download,University of Texas at Austin,"In hybrid additive manufacturing (HAM), toolpaths affect the volume building and
removing during the sequential or iterative hybrid processing since they control the deposition
nozzle or cutting tools. In sequential hybrid additive manufacturing, toolpaths for additive
manufacturing module define the volume directly determines of the shape accuracy and volume
building time. In this paper, we report a new toolpath generation and optimization method for a
developing cold spraying - based HAM process’s additive processing module. This method adopts
a valid physical deposition profile to set scanning parameters and then applies an evolutionary
optimization algorithm to minimize the total scanning length for building a set of ordered
disconnected volumes on a predefined base. The propose method is illustrated by a complex tree
shape model and validated by three selected numerical examples. It has potential to help save
spraying raw materials and time as well as improve shape accuracy.",,,,,,
"['Ahn, S.', 'Murphy, J.', 'Ramos, J.', 'Beaman, J.J.']",2019-10-18T16:22:43Z,2019-10-18T16:22:43Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76252', 'http://dx.doi.org/10.26153/tsw/3341']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Melting,Physical Modeling for Dynamic Control of Melting Process in Direct-SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/33ba8a4c-e37a-40ac-a0bd-ba5a22ff1340/download,,"During the melting process by laser irradiation, it is essential to understand the
phase change processes to get high quality Direct SLS parts especially when highorder scanning paths are needed. This process is a transient three -dimensional heat
conduction problem with a moving heat source and a moving phase boundary. The
process can be simplified to a one-dimensional moving boundary model using
appropriate assumptions. To implement a real-time control strategy, approximate
solutions were found using three methods. Experiments using a CW CO2 laser were
performed on low carbon steelsamples to verify the models’ results. By using first
order differential equations derived from the model, multi-input multi-output (MIMO)
control strategies can be applied.",,,,,,
"['Awenlimobor, Aigbe', 'Wang, Zhaogui', 'Smith, Douglas E.']",2021-12-07T17:53:08Z,2021-12-07T17:53:08Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90736', 'http://dx.doi.org/10.26153/tsw/17655']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['fiber simulation', 'fiber motion', 'finite element analysis', 'large-scale additive manufacturing', 'polymer deposition', 'printed beads']",Physical Modeling: Simulation of Micro-Void Development within Large Scale Polymer Composite Deposition Beads,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63bc40c1-0aca-4ba8-b1cb-9f1ffeeeb583/download,University of Texas at Austin,"Short carbon fiber composites are used in large-scale polymer deposition additive manufacturing due to
their increased stiffness and strength and reduced thermal expansion and print distortion. While much
attention has been given to interlayer properties, less is known about bead microstructure, including the
effect that suspended fibers have on porosity. This paper develops a model for single fiber motion in a
purely viscous flow that is simulated with a custom finite element fiber suspension analysis. Our fiber
simulation is based on Jeffrey’s model assumptions where translational and rotational velocities which zero
applied forces and moments are computed. Velocity gradients along streamlines within the flow of polymer
melt through a large-scale polymer deposition additive manufacturing flow field serve as input. The
pressure distribution around a fiber is computed along the flow path including the die swell expansion at
the nozzle exit. The simulation provides insight into micro-void formation within printed beads.",,,,,,
"['Mensch, Cole', 'Zhou, Wenchao', 'Sha, Zhenghui']",2024-03-26T21:37:31Z,2024-03-26T21:37:31Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124422', 'https://doi.org/10.26153/tsw/51030']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['job placement', 'cooperative 3D printing', 'additive manufacturing']",PHYSICAL VALIDATION OF JOB PLACEMENT OPTIMIZATION IN COOPERATIVE 3D PRINTING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3326e1ee-4481-4086-8d8c-bd3722f3a487/download,University of Texas at Austin,"Cooperative 3D printing (C3DP) is an emerging technology designed to overcome the
limitations of traditional 3D printing, including speed and scalability. C3DP achieves this by
partitioning prints into smaller jobs, e.g., chunks, and assigning them to a team of mobile 3D
printers that work cooperatively in parallel allowing for autonomous additive manufacturing of
large objects via a swarm-based system. Our prior work established a framework for optimizing
job placement by connecting geometric partitioning algorithms with path planning and scheduling
algorithms. However, this framework was not physically validated. In this paper, we present the
first physical validation of the job placement algorithm by chunking and printing two objects using
the proposed algorithm. The objects used in the test cases vary in size and complexity, from a
small and simple object to a large object with intricate geometry. We demonstrate that our
optimized placement algorithm provides results comparable to the physical C3DP system,
providing a significant step forward in the practical implementation of C3DP technology.",,,,,,
"['Gao, Fuquan', 'Sonin, Ain A.']",2018-05-03T19:22:52Z,2018-05-03T19:22:52Z,1993,Mechanical Engineering,doi:10.15781/T2NV99T9T,http://hdl.handle.net/2152/65063,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'digital microfabrication', '3D']",The Physics of Digital Microfabrication with Molten Microdrops,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fede82b5-2da5-4d1a-b317-b1065f811e8a/download,,"Precise deposition of molten microdrops under controlled thermal conditions
provides a means of 3D ""digital microfabrication"" , microdrop by microdrop, under
complete computer control, much in the same way as 2D hard copy is obtained by ink-jet
printing. This paper describes some results from a study of the basic modes of microdrop
deposition and solidification (Gao & Sonin, 1993). The conditions required controlled
deposition are discussed, and some experimental results and theoretical analyses are given
for various basic deposition modes. These include columnar (Le. drop-on-drop)
deposition at low and high frequencies, sweep deposition of continuous beads on flat
surfaces, and repeated sweep deposition for buildup of larger objects or materials.",,,,,,
"['Boulger, Alex M.', 'Chesser, Phillip C.', 'Post, Brian K.', 'Roschli, Alex', 'Hilton, Joshua', 'Welcome, Connor', 'Tsiamis, Nikolaos Y.', 'Love, Lonnie J.', 'Gaul, Katherine T.', 'Rhyne, Breanna J.']",2021-11-15T22:09:41Z,2021-11-15T22:09:41Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90288', 'http://dx.doi.org/10.26153/tsw/17209']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['pick and place', 'fiducials', 'robotic actuator', 'big area additive manufacturing']",Pick and Place Robotic Actuator for Big Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d8b01f83-cb7d-42eb-92de-e0d9dc58da64/download,University of Texas at Austin,"Oak Ridge National Laboratory’s Manufacturing Demonstration Facility has created a system that works
in tandem with an existing large-scale additive manufacturing (AM) system to ‘pick and place’ custom
components into a part as it is printed. Large-scale AM leaves a layered surface finish and is typically post-processed through 5-axis CNC machining. Each surface must be accurately recorded into a laser tracking
system. This process can be simplified with the use of fiducials, small location indicators placed on the surface
of a part. Additionally, the ability to monitor an AM tool via wireless sensors is advantageous to gauge part
health as it is fabricated and later used. The ‘pick and place’ system allows thermocouples, fiducials, and other
sensors to be accurately placed throughout the tool as it is fabricated. This solution has the potential to reduce
time, labor, and cost associated with fabricating, post-processing, and using AM parts.",,,,,,
"Marusak, Ronald E.",2018-05-03T17:09:40Z,2018-05-03T17:09:40Z,1993,Mechanical Engineering,doi:10.15781/T2H98ZX0J,http://hdl.handle.net/2152/65041,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['ink-jet printing', 'TAB', 'metal printer']",Picoliter Solder Droplet Dispensing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/531cddb4-6ef3-45b5-8df9-c252c5a89703/download,,"A device based on ink-jet printing technology was used to produce and place
molten solder droplets, approximately 25-125pm in diameter, onto substrates. The
advantages of an ink-jet based system are direct production of metallic objects, no postcure,
low cost, and the repeatability and resolution for small feature sizes. This paper
describes the device, the supporting hardware, and experimental procedures. Results show
that bump size can be varied by placing in quick succession, multiple droplets as well as
by resizing the device and by altering the signal.",,,,,,
"['Evans, Emmeline', 'McComb, Christopher']",2021-12-01T21:35:24Z,2021-12-01T21:35:24Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90621', 'http://dx.doi.org/10.26153/tsw/17540']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'PLA claves', 'wooden claves', 'claves', 'vibrations', 'frequency']",Pitch Imperfect: Designing 3D Printed Claves to Mimic the Sounds of Their Wooden Counterparts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ac836af-02e2-4a05-9430-43252e09f864/download,University of Texas at Austin,"Despite the benefits afforded students by music education, public schools operating on
insufficient budgets often cut music programs to reduce expenses. Students deserve access to
high quality instruments, regardless of socioeconomic status or district funding. Therefore, the
goal of this research is to develop 3D printed, PLA claves that reproduce the sound of wooden
claves. This study examined clave vibration by approximating claves as damped, simply
supported, thin beams. The frequency predictions obtained from that model are compared to
experimental results obtained by recording clave prototypes and analyzing the resulting
frequency spectra. Results indicate that while it is technically feasible to 3D print a correctly
pitched PLA clave, the design would not be suitable for an education instrument.",,,,,,
"['Ghazanfari, Amir', 'Li, Wenbin', 'Leu, Ming C.', 'Landers, Robert G.']",2021-10-21T18:23:53Z,2021-10-21T18:23:53Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89419,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['horizontal staircase effect', 'freeform extrusion fabrication', '3D parts', 'adaptive rastering']",Planning Freeform Extrusion Fabrication Processes with Consideration of Horizontal Staircase Effect,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3331da7f-664d-44b2-93b6-8975c2bea16a/download,University of Texas at Austin,"An algorithm has been developed to estimate the “horizontal” staircase effect and a technique is
proposed to reduce this type of geometrical error for freeform extrusion fabrication processes of 3D “solid”
parts. The adaptive rastering technique, proposed in this paper, analyzes the geometry of each layer and changes
the width of each line of the raster adaptively in order to reduce the staircase error and increase the productivity
simultaneously. For each line, the maximum width that results in a staircase error smaller than a predefined
threshold is determined for decreasing the fabrication time or increasing the dimensional accuracy, or both. To
examine the efficacy of the proposed technique, examples are provided in which staircase errors and fabrication
times are compared between uniform and adaptive rastering methods for each part. The results show a
considerable improvement in accuracy and/or fabrication time for all parts studied when using the adaptive
rastering technique.",,,,,,
"['Yan, Jingyuan', 'Battiato, Ilenia', 'Fadel, Georges M.']",2021-10-26T18:18:58Z,2021-10-26T18:18:58Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89549,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['functionally graded material', 'direct metal deposition', '2D model', 'thin-walled parts', 'process parameters']",Planning the Process Parameters During Direct Metal Deposition of Functionally Graded Thin-Walled Parts Based on a 2D Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e5f3cff5-ec38-4fca-bbe9-1d3aea69e161/download,University of Texas at Austin,"The need for functionally graded material (FGM) parts has surfaced with the development
of material science and additive manufacturing techniques. Direct Metal Deposition (DMD)
processes can locally deposit different metallic powders to produce FGM parts. Yet inappropriate
mixing of materials without considering the influence of varying dilution rates and the variation
of material properties can result in inaccurate material composition ratios when compared to the
desired or computed compositions. Within such a context, this paper proposes a 2D simulation
based design method for planning the process parameters in the DMD manufacturing of designed
thin-walled parts. The proposed scheme is illustrated through two case studies, one of which is a
part with one-dimensional varying composition and the other with two dimensional variation.
Using the proposed method, the process parameters can be planned prior to the manufacturing
process, and the material distribution deviation from the desired one can be reduced.",,,,,,
"['Holzman, Noah', 'Francis, Lorraine']",2021-11-02T19:17:04Z,2021-11-02T19:17:04Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89870,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['pneumatic system', 'direct write 3D printing', 'direct write printing']",Pneumatic System Design for Direct Write 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/86da84df-3e20-405e-95aa-066bcb5d3a0c/download,University of Texas at Austin,"Direct write 3D printing methods are interesting due to the diverse palette of materials
available for the process. In this work, a pneumatic system for direct write printing is built using
off-the-shelf hardware and synchronized with an open-source firmware for motion control. The
time to steady-state pressure of the system is found to be ~150 ms for the range of pressures
tested; this delay can lead to defects on the start of a path. Proof of concept is established by
printing with a high viscosity, room temperature curing silicone using a 410 µm nozzle and 300
µm layer height. Test prints show a high degree of dimensional accuracy and consistent layer
height over 10s of layers.",,,,,,
"['Lao, S. C.', 'Koo, J. H.', 'Yong, W.', 'Lam, C.', 'Zhou, J.', 'Moon, T.', 'Piccione, P. M.', 'Wissler, G.', 'Pilato, L.', 'Luo, Z. P.']",2020-03-10T17:16:43Z,2020-03-10T17:16:43Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80232', 'http://dx.doi.org/10.26153/tsw/7251']",eng,2008 International Solid Freeform Fabrication Symposium,Open,selective laser sintering,Polyamide 11-Carbon Nanotubes Nanocomposites: Preliminary Investigation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2ad1caf-162c-42b1-afeb-96024e104446/download,,"The objective of this research is to develop an improved polyamide 11 (PA11) polymer with
enhanced flame retardancy, thermal, and mechanical properties for selective laser sintering
(SLS) rapid manufacturing. In the present study, a nanophase was introduced into polyamide 11
via twin screw extrusion. Arkema Rilsan® polyamide 11 molding polymer pellets were used
with 1, 3, 5, and 7 wt% loadings of Arkema’s GraphistrengthTM multi-wall carbon nanotubes
(MWNTs) to create a family of PA11-MWNT nanocomposites.
Transmission electron microscopy and scanning electron microscopy were used to determine
the degree and uniformity of dispersion. Injection molded test specimens were fabricated for
physical, thermal, mechanical properties, and flammability measurements. Thermal stability of
these polyamide 11-MWNT nanocomposites was examined by TGA. Mechanical properties such
as ultimate tensile strength, rupture tensile strength, and elongation at rupture were measured.
Flammability properties were also obtained using the UL 94 test method. All these different
methods and subsequent polymer characteristics are discussed in this paper.",,,,,,
"['Lao, S.C.', 'Kan, M.F.', 'Lam, C.K.', 'Chen, D.Z.', 'Koo, J.H.', 'Moon, T.', 'Londa, M.', 'Takatsuka, T.', 'Kuramoto, E.', 'Wissler, G.', 'Pilato, L.', 'Luo, Z.P.']",2021-09-30T18:25:10Z,2021-09-30T18:25:10Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88270', 'http://dx.doi.org/10.26153/tsw/15211']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['multifunctionial polyamide 11 polymer', 'enhanced properties', 'selective laser sintering', 'rapid manufacturing', 'nanotechnology', 'multi-wall carbon nanotubes', 'nanocomposites']","Polyamide 11-Carbon Nanotubes Nanocomposites: Processing, Morphological, and Property Characterization",Conference paper,https://repositories.lib.utexas.edu//bitstreams/7981e45c-bc53-4824-bfc8-1261c74c17dc/download,University of Texas at Austin,"The objective of this research is to develop a multifunctional polyamide 11 (PA11)
polymer with enhanced electrical, thermal, mechanical, and flammability properties for
selective laser sintering (SLS) rapid manufacturing through the use of nanotechnology. In
the present study, a nanophase was introduced into PA11 powder via rotation &
revolution and twin screw extrusion techniques to disperse the MWNTs in the PA11
pellet. Arkema Rilsan® polyamide 11 molding polymer pellets were used with 1, 3, 5,
and 7 wt% loadings of Arkema’s Graphistrength™ multi-wall carbon nanotubes
(MWNTs) to create a family of PA11-MWNT nanocomposites using twin screw
extrusion technique. Arkema Rilsan® polyamide 11 powders were blended with 5 wt%
loading of Graphistrength™ MWNTs using the rotation & revolution technique to create
another set of PA11-MWNT nanocomposites.
Transmission electron microscopy and scanning electron microscopy were used to
determine the degree and uniformity of dispersion of MWNTs in the PA11 polymer.
Injection and compression molded test specimens were fabricated for physical, electrical,
thermal, mechanical, and flammability properties characterization. Thermal stability of
these polyamide 11-MWNT nanocomposites was examined by TGA. Kinetic parameters
were calculated using isoconversion technique. Electrical properties were measured using
ASTM D257. Mechanical properties such as ultimate tensile strength, rupture tensile
strength, and elongation at rupture were measured. Flammability properties were
obtained using the UL 94 test method. All these different test methods and subsequent
polymer characteristics are discussed in this paper.",,,,,,
"['Koo, J. H.', 'Lao, S.', 'Ngyuen, K.', 'Cheng, J.', 'Pilato, L.', 'Wissler, G.', 'Ervin, M.']",2020-03-02T14:37:01Z,2020-03-02T14:37:01Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80127', 'http://dx.doi.org/10.26153/tsw/7148']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Wide angle X-ray diffraction,Polyamide Nanocomposites for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/26576f56-0c88-4d2a-97cf-40e9b13605fe/download,,"Current polyamide 11 and 12 are lacking in fire retardancy and high strength/high
heat resistance characteristics for a plethora of finished parts that are desired and required
for performance driven applications. It is anticipated that nanomodification of polyamide
11 and 12 will result in enhanced polymer performance, i.e., fire retardancy, high strength
and high heat resistance for polyamide 11 and 12. It is expected that these findings will
expand the market opportunities for polyamide 11 and 12 resin manufacturers.
The objective of this research is to develop improved polyamide 11 and 12 polymers
with enhanced flame retardancy, thermal, and mechanical properties for selective laser
sintering (SLS) rapid manufacturing (RM). A nanophase was introduced into the
polyamide 11 and 12 via twin screw extrusion to provide improved material properties of
the polymer blends. Arkema RILSAN® polyamide 11 molding polymer pellets and
Degussa VESTAMID® L1670 polyamide 12 were examined with three types of
nanoparticles: chemically modified montmorillonite (MMT) organoclays, surface
modified nanosilica, and carbon nanofibers (CNFs) to create polyamide 11 and 12
nanocomposites.
Wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM)
were used to determine the degree of dispersion. Injection molded test specimens were
fabricated for physical, thermal, mechanical properties, and flammability tests. Thermal
stability of these polyamide 11 and 12 nanocomposites was examined by TGA.
Mechanical properties such as tensile, flexural, and elongation at break were measured.
Flammability properties were also obtained using the Cone Calorimeter at an external
heat flux of 50 kW/m2. TEM micrographs, physical, mechanical, and flammability
properties are included in the paper. Polyamide 11 and 12 nanocomposites properties are
compared with polyamide 11 and 12 baseline polymers. Based on flammability and
mechanical material performance, selective polymers including polyamide 11
nanocomposites and control polyamide 11 were cryogenically ground into fine powders
and fabricated into SLS parts.",,,,,,
"['McMorrow, Brain', 'Chartoff, Richard', 'Lucas, Pierre', 'Richardson, Wade']",2020-02-20T21:07:06Z,2020-02-20T21:07:06Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80055,eng,2005 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Polymer Matrix Nanocomposites by Inkjet Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/263bc2e5-d492-4c9d-8fcc-25e9f0f719c0/download,,"This paper describes work on a continuing project to form functional composites that contain
ceramic nanoparticles using a Solid Freeform Fabrication (SFF) inkjet printing method. The process
involves inkjet deposition of monomer/particle suspensions in layers followed by curing each layer in
sequence using UV radiation. The reactive monomer is hexanediol-diacrylate (HDODA); the polymer
forming reaction proceeds by a free radical mechanism. The liquid monomer containing nanoparticles
is essentially a printing ink formulation. Successfully suspending the particles in the monomer is
critical. We have developed a surface treatment method for forming stable suspensions of the
nanoparticles so that they remain discrete throughout the processing sequence.
The SFF process involves careful control of the polymer cure so that the interface between layers
is seamless and residual stresses in the composites are eliminated. An immediate use for such
composites is in optical applications as gradient refractive index lenses (GRIN). GRIN lenses have
planar surfaces, eliminating the need for costly grinding and polishing. The planar surfaces also
eliminate optical aberrations that result at the edges of spherical lenses and diminish the accuracy of
focus.
If the appropriate nanoparticles are fully dispersed they will modify the polymer's refractive index
without interfering with light transmission. The effect is additive with volume concentration. Using
'inks' of different compositions in a multiple nozzle inkjet printer allows the formation of composites
with precise composition gradients. Since an object is built one planar layer at a time, changes can be
made readily both within each layer and from layer to layer. Inkjet printing with picoliter resolution is
ideal for this task.
Working with SiC nanoparticles in HDODA as a model system for demonstrating the inkjet
deposition process, nanocomposite films with a linear concentration gradient varying from 0 to 4.5%
(wt) were fabricated on Silicon wafers. These composites are 30 layer films, which total 140µm in
thickness. Each layer in the composite is about 5 µm in thickness. Analytical methods for
characterizing the dispersion of the nanoparticles in the composite and some of the salient optical
properties of the composites also were established. The status of the program is reviewed in this
paper.",,,,,,
"['Hüsler, A.', 'Wildman, R.D.', 'Alexander, M.R.']",2021-10-21T21:01:10Z,2021-10-21T21:01:10Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89447,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['inkjet printing', 'polymer particle formation', 'biodegradable', 'photocrosslinkable']",Polymer Particle Formation Using Inkjet Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/040f3941-ac50-4924-9dc6-ffa69644d183/download,University of Texas at Austin,"Exciting advances have been made in biomaterials research, through both relating material
properties to cell response and discovery of new materials via high throughput screening. This
area of research is still hindered though by the paucity of information on the physicochemical
parameters governing the response of cells to a broad range of materials. Herein, a combinatorial
library of biodegradable, photocrosslinkable and microparticle-forming polymers is generated by
transforming a macro-performed pipetting experiment into a micro-sized piezoelectric inkjet
printing. Physiochemical properties such as density, polymerization rate, surface tension,
viscosity and solubility have been shown to be critical for successful single and multiple polymer
structured microparticles. The vision is to mature this effort for applications that require
biocompatibility such as drug delivery and cell carriers in regenerative medicine strategies to
engineer cell functions.",,,,,,
"['Cruz, Fabio', 'Lanza, Silvia', 'Boudaoud, Hakim', 'Hoppe, Sandrine', 'Camargo, Mauricio']",2021-10-21T20:38:07Z,2021-10-21T20:38:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89441,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['polymer recycling', 'additive manufacturing', '3D printers', 'filament extruders', 'open source']",Polymer Recycling and Additive Manufacturing in an Open Source Context: Optimization of Processes and Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5aa71bbe-b1be-479b-abd1-66ef9fe48ccd/download,University of Texas at Austin,"Polymer recycling is a way to reduce environmental impacts of accumulation of polymeric waste materials.
However, low recycling rates are often observed in conventional centralized recycling plants mainly to the challenge of
collection and transportation for high-volume low-weight-polymers in conventional centralized recycling plants. As
the democratization of open-source 3D printers is going forward thanks to initiatives such as FabLab environments,
there is a growing interest on how to use this technology to improve the efficiency of use of raw materials. Studies
have been proposed in order to recycle waste polymer into open-source 3D printer feedstock. The recycling of
high-density polyethylene (HDPE) issued from bottles of used milk jugs through use of an open-source filament
fabricator system called RecycleBot has been evaluated. In this study, we propose an evaluation of the mechanical
recyclability of Polylactic Acid (PLA), material widely used in the open-source 3D printing context, in order to
establish the viability of this recycled material to be used in the open-source 3D printers. The degradation of
the material’s mechanical and rheological properties after a number of cycles of multiple extrusion and printing
processes is evaluated. The characterization of recycled raw materials for open-source 3D printing has implications
not only to reduce the environmental impact of polymers waste, but also it will allow us to understand the technical
requirements and challenges for development of open-source filament recycle machine/process.
The coupling of open-source 3D printers and filament extruders can offer the bases of a new distributed polymer
recycling paradigm, which reverses the traditional paradigm of centralizing recycling of polymers where is often
uneconomic and energy intensive due to transportation embodied energy. Moreover, this characterization also will
allow the exploration of new source of materials and new composite materials for open-source 3D printing, in order
to improve the quality of products made by this technology.",,,,,,
"['Johnson, David M.', 'Beck, Victor', 'Valente, Michael', 'Völkel, Armin', 'Chang, Norine', 'Jose, Arun', 'Lancaster, Cory', 'Biegelsen, Dave', 'Elrod, Scott']",2021-10-28T20:51:51Z,2021-10-28T20:51:51Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89697,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['polymer spray deposition', 'electrostatic patterning', 'aerosol-based deposition', 'additive manufacturing', 'PARC']","Polymer Spray Deposition: A Novel Aerosol-Based, Electrostatic Digital Deposition System for Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/48c62ab7-2eb1-45dd-ba4a-9b82325b236f/download,University of Texas at Austin,"In order to address some of the shortcomings from traditional additive manufacturing
methods, PARC, a Xerox Company, is developing a new additive manufacturing method for
polymers that uses electrostatic patterning in combination with a new method of creating
aerosols to directly pattern a wide range of thermoplastics with high resolution. Our aerosol
technology takes advantage of the non-Newtonian nature of polymers to create monodisperse
small droplets. In addition, we leverage ionographic printing techniques to pattern thick
substrates and create digital thin films. This technology can bring 3D printing of polymers into a
performance range where the technology can be used to replace more traditional techniques such
as injection molding and machining.",,,,,,
"Lee, Biing-Lin",2018-04-12T18:45:35Z,2018-04-12T18:45:35Z,1991,Mechanical Engineering,doi:10.15781/T2XP6VM3G,http://hdl.handle.net/2152/64284,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'BFGoodrich R&D Center', 'CAD systems', 'CAM systems', 'CAE systems']",Polymeric Powder Material Technology for Selective Laser Sintering: The Overall View,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7e666990-692c-4e65-b7d6-9c570d562bcd/download,,"This paper de.als with polymeric POwder technology relating to the conversion of raw polymeric
materialsintoSelective LaserSinteringi(SLS) mtlterials. Generally, all SLS·polymeric powders go
through similarexperiencesinmaterial- SLS interaction, such· as powderfeeding andsintering.
The·desirtlblematerial - SLS interaction can be. achieved by a set of unit oPerations that converts a
raw materialforSLS fabrication. The unit operations are: compounding, size reduction, attrition,
size enlargement, and poWder mixing.",,,,,,
"['Rauniyar, Santosh K.', 'Chou, Kevin']",2021-11-30T20:57:06Z,2021-11-30T20:57:06Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90545', 'http://dx.doi.org/10.26153/tsw/17464']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Ti64 alloy', 'porosity', 'computed tomography', 'CT']",Porosity Analysis and Pore Tracking of Metal AM Tensile Specimen by Micro-CT,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6442a179-04e5-426c-af38-9e55f3bdd15b/download,University of Texas at Austin,"In this study, the porosity of Ti-6Al-4V (Ti64) tensile specimen fabricated by laser
powder bed fusion (L-PBF) with varying three process conditions was investigated. The
variation included the energy density in fabrication (3 levels), the build location (3 levels)
and the build orientation (2 levels) for a constant scan speed of 600 mm/s. The tensile
specimens were scanned using a micro-CT system before and after tensile testing. The
porosity of the specimens varied significantly according to the energy density and the build
direction, but only a minor effect of the location change was observed. The fractured
specimens showed a significant increase, more than nine percent increase in the pore
volume in all cases, for the pore volume as well as the porosity percentage. Also, few large
pores were tracked in some of the fractured samples and compared with the as-built
counterpart to observe the change in pore morphology.",,,,,,
"['Nagahama, Takaya', 'Mizoguchi, Takashi', 'Yonehara, Makiko', 'Kyogoku, Hideki']",2021-11-18T01:06:31Z,2021-11-18T01:06:31Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90384', 'http://dx.doi.org/10.26153/tsw/17305']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'process parameters', 'H13 tool steel', 'mechanical properties']",The Porosity and Mechanical Properties of H13 Tool Steel Processed by High-Speed Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8e7165d-9b08-4579-9e01-ae118a38efdd/download,University of Texas at Austin,"Additive Manufacturing (AM) technology has the advantages of complicated geometry
fabrication and integration of multiple parts. Selective Laser Melting (SLM), which is one of the
AM technologies, generally takes longer manufacturing time than other manufacturing methods.
In this research, the process parameters, which can achieve high-speed additive manufacturing of
H13 tool steel, are investigated using a SLM machine with a 1 kW multi-mode fiber laser. As a
result, the optimal process window has been determined in the process map of the laser power
and the scan speed. High laser power in the process window is estimated to increase the
manufacturing speed by 50 % of that with the conventional parameters. The specimen
manufactured with the optimal parameters has a tensile strength of 1500 MPa, which is
equivalent to the bulk samples.",,,,,,
"['Khanzadeh, Mojtaba', 'Bian, Linkan', 'Shamsaei, Nima', 'Thompson, Scott M.']",2021-10-28T20:17:21Z,2021-10-28T20:17:21Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89688,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser based additive manufacturing', 'porosity', 'porosity detection', 'melt pool', 'melt pool morphology', 'clustering', 'laser engineered net shaping']",Porosity Detection of Laser Based Additive Manufacturing Using Melt Pool Morphology Clustering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a26db74a-d6a2-4e60-91ba-6a4c8e0c987a/download,University of Texas at Austin,"The microstructural and mechanical properties of Laser Based Additive Manufacturing
(LBAM) are still inconsistent and unreliable, which is a major barrier that prevents Additive
Manufacturing (AM) from entering main stream production. The key challenge is the lack of
understanding for the underlying process-properties relationship. We monitor Laser Engineered
Net Shaped (LENS) process using a state-of-art thermal image system, and the resulting high-speed Melt Pool (MP) data stream is used to characterize the complex thermo-physical process.
We propose a novel method based on Self-Organizing Map to cluster the MPs based on their
morphology and link MPs clusters’ characteristics to the porosity of fabricated parts, which is
crucial to mechanical properties of parts. The results are validated using X-Ray tomography of Ti-64 thin-wall. Our approach identifies various patterns of MP morphology, which corresponds to
different types of porosities. The proposed method can potentially be used to certify the part quality
in a real-time and non-destructive manner.",,,,,,
"['Qi, Ting', 'Zhu, Haihong', 'Yin, Jie', 'Chen, Baijin', 'Hu, Zhiheng', 'Zeng, Xiaoyun']",2021-11-02T14:47:26Z,2021-11-02T14:47:26Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89815,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['porosity development', 'cracking behavior', '7xxx series', 'Al-Zn-Mg-Cu', 'selective laser melting']",Porosity Development and Cracking Behavior of Al-Zn-Mg-Cu Alloys Fabricated by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77087821-3213-4c80-b723-8dce57f59ffe/download,University of Texas at Austin,"Selective laser melting (SLM) of the 7xxx series Al alloy (Al-Zn-Mg-Cu) faces more challenge than
other series aluminum alloy such as Al-Si system because of the high hot-cracking sensitivity. The porosity
development and crack behavior of Al-Zn-Mg-Cu alloys fabricated at various scanning speeds in SLM process,
as well as the influence of molten pool geometry were systematically investigated in this paper. Results show
that the relative density over 99% can be achieved when the applied scanning speed is 150 mm/s. However,
cracks are observed in almost all the as-deposited samples. The morphology, distribution and density of cracks
were varied with the different molten pool geometry and scanning speed.",,,,,,
"['Susan, D.F.', 'Puskar, J.D.', 'Brooks, J.A.', 'Robino, C.V.']",2019-09-20T15:16:27Z,2019-09-20T15:16:27Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75919', 'http://dx.doi.org/10.26153/tsw/3018']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Porosity,Porosity in Stainless Steel LENS Powders and Deposits 50,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bfb0e12f-fbc4-4372-8d00-1e2c3b6cf94b/download,,"Laser Engineered Net Shaping (LENS) utilizes a laser beam to melt fine powders to
produce three-dimensional engineering structures line by line and layer by layer. When building
these structures, defects including lack-of-fusion (LOF) at interlayer boundaries and intralayer
porosity are sometimes observed. LOF defects can be minimized by adjusting processing
parameters, but the sources of intralayer porosity are less apparent. In this paper, the amount and
size distributions of 17-4PH and 304L powders and pores within the powder were characterized
in parallel with the intralayer porosity in LENS deposits fabricated from the same materials.
Intralayer porosity increased with increased powder porosity; but was not well correlated with
deposition parameters. The results demonstrate the importance of careful characterization and
specification of starting powders on the quality of the final LENS deposits.",,,,,,
"['Kleszczynski, S.', 'Ladewig, A.', 'Friedberger, K.', 'zur Jacobsmühlen, J.', 'Merhof, D.', 'Witt, G.']",2021-10-19T20:33:42Z,2021-10-19T20:33:42Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89333,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Laser Beam Melting', 'part position', 'surface roughness']",Position Dependency of Surface Roughness in Parts from Laser Beam Melting Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9530c12b-cafb-4e85-ab74-bba6311060df/download,University of Texas at Austin,"Laser Beam Melting is a promising Additive Manufacturing technology for the production of complex
metal components. During batch production of multiple identical parts in a single build job, we observed parts
with deviating surface roughness in certain areas, which all faced away from the laser. This suggests a dependency
of surface roughness on the part position in the build chamber. In this work we systematically reproduce and
analyze this effect. We place hollow pyramids with twelve faces and two different overhanging angles at nine
positions on the substrate plate and build this setup twice, using an imaging setup for process documentation.
Surface roughness is measured by contact profilometry on three lines for each pyramid face. Our experiments
reproduce the effect. Based on these findings we present a hypothesis for the cause and show metallographic
images to support our theory. As a consequence, the position relative to the laser should be considered in the
design phase for parts with high surface quality requirements.",,,,,,
"['King, B.A.', 'Rennie, A.E.W.', 'Taylor, J.P.', 'Bennett, G.R.']",2021-11-04T13:38:49Z,2021-11-04T13:38:49Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89956,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['post processing treatment', 'post processing', 'nylon 12', 'laser sintering']",Post Processing Treatments on Laser Sintered Nylon 12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3f2281a-9361-4b1e-945b-68194a5ea51e/download,University of Texas at Austin,"The laser sintering of polymers is an established process producing components with
well-documented material properties. Whilst these properties are inferior to those of
injection moulded nylon 12, they are suitable for prototyping and several specialist
production applications. Broadening the applicability of the process to a wider range of
manufacturing applications, can be accomplished by rendering the material properties of
sintered nylon closer to those of injection moulded nylon. This paper reports on a series of
post-processing treatments which have been carried out to enhance the mechanical properties
of sintered nylon. The work has examined the effects of heat, pressure, infiltration with
methyl methacrolate and combinations of these treatments. Results are reported on the
impact of the treatments on the elongation and Ultimate Tensile Strength (UTS) of the test
samples, with heated pressured samples improving UTS by 2MPa, and infiltrated parts
increasing elongation by 5.2%.",,,,,,
"['Rybalcenko, K.', 'Charlesworth, R.E.', 'Folgar, L.', 'Ioannides, G.', 'Crabtree, J.G.']",2021-12-01T21:24:39Z,2021-12-01T21:24:39Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90618', 'http://dx.doi.org/10.26153/tsw/17537']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'post-process', 'COVID-19 nasopharyngeal swabs', 'COVID-19']",Post-Processing of Additively Manufactured Covid-19 Nasopharyngeal Swabs at Scale,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c116572-7f55-419b-842c-b77d761fb4ae/download,University of Texas at Austin,"A methodology to post-process oral/respiratory Additively Manufactured
medical components methods is presented. The system involves PostPro3D®
smoothing machine by AMT, picking/racking module, industrial robot, conveyors and
is used to smooth the surfaces of Covid-19 Nasopharyngeal Swabs manufactured at-scale using powder-based methods. The presented process for large scale postprocessing of Additively Manufactured articles has undergone all necessary medical
verifications and has been already deployed in the field.",,,,,,
"['Zarringhalam, Hadi', 'Hopkinson, Neil']",2019-11-21T18:39:19Z,2019-11-21T18:39:19Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78564', 'http://dx.doi.org/10.26153/tsw/5620']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Polyamide,Post-Processing of DuraForm� Polyamide with Small-Scale Features,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3e191c3-b3f6-465f-b240-39e5c97d62c4/download,,"In recent years layer manufacturing processes have evolved from Rapid Prototyping (the
production of pre-production prototypes) to Rapid Manufacture (the production of end use parts)
where limitations of the processes do not affect end use. There is no doubt that applications for
Rapid Manufacture will grow in coming years, however there are a number of current limitations
that will need to be addressed so as to maximise the scope for Rapid Manufacturing applications.
One of the main limitations for the adoption of Rapid Manufacturing is material properties of the
parts produced. This research has looked at the possibility of increasing the range of material
properties that may be achieved from parts made using current commercial Laser Sintering
systems.
A series of tensile and impact test parts were built using DuraformTM powder on a 3DSystems
Vanguard machine. These parts were then subjected to various form of post-processing including
thermal treatment and infiltration with polymer infiltrants. The parts were subjected to tensile
and impact tests with results showing that thermal post-processing achieved preferable results
when compared with infiltration. Heating above the glass transition temperature yielded superior
results though as the melt temperature was approached issues of deformation arose. These initial
results have formed the basis for further work to consider how material properties for Rapid
Manufacture by Laser Sintering may be improved.",,,,,,
"['Nelson, J.C.', 'Vail, N.K.']",2018-04-12T18:52:13Z,2018-04-12T18:52:13Z,1991,Mechanical Engineering,doi:10.15781/T2SX64S93,http://hdl.handle.net/2152/64285,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'post-processing', 'polycarbonate', 'densification']",Post-Processing of Selective Laser Sintered Polycarbonate Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a3ee1b1-e849-4428-95bf-23c29e9036d6/download,,"St\ldies were conducted·to det~rmine the effect of
press\lre onpost-prpeessingofpolycarbonate coupons. No
significant differences betweencou.pons processed at
atmospheric •cQndidons.. andcouponsprpeessedin.vacuum
were •observed. However, anisotropic shrinkage .was
observedin.thez-directionnormal to thesintering plane.
Thisphenomenawasfurtl1erinvestigated usingsYIllmetrical
polycarbonatecubespr9(iuced by Selective LaserSintering
using yariedlas~rpoweryariedpowderlayer thickness, and
varied powder bed temperatures",,,,,,
"['Xian, Y.', 'Rosen, D.W.']",2021-11-04T19:46:49Z,2021-11-04T19:46:49Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90014', 'http://dx.doi.org/10.26153/16935']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['level set based topology optimization', 'part boundary', 'support materials', 'post-processing', '3D printing']",A Post-Processing Procedure for Level Set Based Topology Optimization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/084febbc-8ff8-41e3-8b8a-c9f38838c30d/download,University of Texas at Austin,"This paper addresses two issues: 1. Topology optimization yields designs that may require
support structures if additively manufactured, which increase material and clean-up costs. 2.
Topologically optimized designs consist of discretized geometry which makes subsequent
engineering difficult, hence the increasing need to somehow render TO results to parameterized
CAD models. This paper presents a procedure that, after a standard level set based topology
optimization, firstly identifies certain regions on the part boundary that may require support
materials or may cause staircase effect during 3D printing, then replaces these boundary segments
with similar-shaped printable design features. Additionally, other boundary regions are fitted with
simple geometric entities, so that the part boundary can be completely defined by geometric
parameters of design primitives.",,,,,,
"['Kruse, C.S.', 'Meile, D.H.', 'Salajeghe, R.', 'Spangenberg, J.']",2023-04-03T15:37:16Z,2023-04-03T15:37:16Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117717', 'http://dx.doi.org/10.26153/tsw/44596']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Post-Processing Volumetric Additive Manufacturing (VAM) Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b39d1f05-d96e-42f5-ac4c-72fafb26702d/download,,"Volumetric additive manufacturing, a new promising 3D-printing technology, has 
shown great potential to revolutionize the Additive Manufacturing industry. Within the field 
of Volumetric Additive Manufacturing, preliminary research has predominantly been focused 
on improving projection algorithms and optical systems as well as expanding its applicability 
to different materials, and little attention has therefore been paid to the post-processing phase 
of the printing process itself. As the surface of components produced by volumetric additive 
manufacturing using currently available photopolymer and published projection algorithms is 
not fully cured by the end of projection, it is highly susceptible to damage and deformation in 
the post-processing phase. In this study, a comparison has been made between the effects of 
different post-processing methods and techniques on the dimensions of the final post-processed 
components. The results show that it is a non-trivial task to maintain the surface quality and 
dimensions of components produced by volumetric additive manufacturing throughout post-
processing, and it is therefore important to establish a well-defined method of post-processing 
that consistently yields satisfactory components.",,,,,,
"['Raman, R.V.', 'Rele, S.V.', 'Anderson, R.L.']",2018-05-03T19:36:07Z,2018-05-03T19:36:07Z,1993,Mechanical Engineering,doi:10.15781/T24X5507Z,http://hdl.handle.net/2152/65067,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Ceracon Process', 'SFF', 'CAD', 'CAM']",Potential Application of Solid Free-Form Fabrication (SFF) Process in Ceracon P/M Forging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ed197074-363e-45d8-8b52-a0c5f4e8d2f6/download,,"The Ceracon Process is a patented[ll, low cost powder metallurgy process for
achieving near-net-shape, full density parts. It. isasimple.·consolidation.technique which
utilizes conventionalpowder metallurgyequipmenfand set-up. The Cetacon Process is a
quasi-isostatic,hot consolidation technique, that utilizes a ceramic particulate material as a
pressure transmitting medium instead ofagasmedia as is used in. hipping. Pressures up to
200 K.si can be used and a broad range ofmetallic, ceramic, and polymeric materials and
composites have been successfully processed£2-6] .",,,,,,
"['Buswell, R. A.', 'Soar, R.', 'Gibb, A.', 'Thorpe, A.']",2020-02-24T15:41:54Z,2020-02-24T15:41:54Z,9/7/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80086', 'http://dx.doi.org/10.26153/tsw/7107']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Freeform Construction,The Potential of Freeform Construction Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1bf0971e-f09d-46c1-9c27-3d511d19939f/download,,"The level of automation technology and processes control found in modern day construction
lags significantly behind other industries such as automotive and aerospace. The construction
industry has health and safety issues and still uses traditional methods of procurement. These
problems are compounded by diminishing skills in the labour force. Methods of production
must change if these issues are to be resolved and Freeform Construction is a collection of
processes that could have potential impact. This paper outlines some of the major issues
facing construction and sets a context with examples of digital fabrication in construction.
Freeform Construction is defined and potential applications are presented and related to
application scale. The viability of two potential applications are investigated in terms of cost.",,,,,,
"['Binder, M.', 'Anstaett, C.', 'Horn, M.', 'Herzer, F.', 'Schlick, G.', 'Seidel, C.', 'Schilp, J.', 'Reinhart, G.']",2021-11-09T15:58:45Z,2021-11-09T15:58:45Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90104', 'http://dx.doi.org/10.26153/tsw/17025']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['multi-material processing', 'laser-based powder bed fusion', 'LPBF', 'potentials', 'challenges']",Potentials and Challenges of Multi-Material Processing by Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/557451b0-7062-4aff-9ae2-972961fea417/download,University of Texas at Austin,"Multi-material additive manufacturing offers a multitude of opportunities for increasing functional
integration beyond the current state of the art. However, the real potential is only vaguely described and there are
also challenges alongside the new opportunities. This paper presents a systematic collection of the challenges to
be overcome by laser-based powder bed fusion before it can provide industrially relevant multi-material
processes. Amongst others, parameter adaptation to avoid micro-cracking, relevant process monitoring
technologies (e.g., thermography-based layer monitoring) and potential approaches for powder separation (e.g.,
using ferromagnetism) are described. Furthermore, to exploit the full potential of multi-material designs, possible
concepts for the integration of fully functioning mechatronic devices into multi-material parts are also presented.",,,,,,
"['Jahnke, U.', 'Lindemann, C.', 'Moi, M.', 'Koch, R.']",2021-10-12T18:58:27Z,2021-10-12T18:58:27Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88720', 'http://dx.doi.org/10.26153/tsw/15654']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'piracy', 'piracy prevention', 'plagiarism', 'product tagging']",Potentials of Additive Manufacturing to Prevent Product Piracy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ded408bc-d54b-4106-bb9c-45f1959f6dc3/download,University of Texas at Austin,"Infringements of intellectual and industrial properties rights in terms of imitations of products
are continuously increasing. Massive economic and reputational damages are consequences
for concerned companies. One solution to this problem can be the use of Additive
Manufacturing (AM) technologies. This production technology enables complex designed
products and specific product properties due to the use of different manufacturing processes
and materials, which can help preventing product piracy safety measures of products can
highly benefit from these capabilities, which have not been possible yet. The layer wise
process allows, for example, to implement identifiable marks under the parts surface and to
adjust mechanical properties in a certain way. The use of AM can strongly reduce the
economic efficiency of plagiarism. This paper will present approaches to product piracy
prevention by the use of AM focusing on the tagging of products, preventive measures as well
as the interplay of these types.",,,,,,
"['Allison, Jared', 'Sharpe, Conner', 'Seepersad, Carolyn Conner', 'Kubiak, Steven']",2021-11-08T22:59:44Z,2021-11-08T22:59:44Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90068', 'http://dx.doi.org/10.26153/tsw/16989']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['metrology', 'powder bed fusion', 'design for additive manufacturing', 'DFAM', 'test parts', 'design guidance', 'selective laser sintering']",Powder Bed Fusion Metrology for Additive Manufacturing Design Guidance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/506b24c1-e3de-495e-9517-3124ce0758cc/download,University of Texas at Austin,"Design for additive manufacturing (DFAM) guidelines are important for helping designers
avoid iterations and fully leverage the design freedoms afforded by additive manufacturing (AM).
Guidelines can be generated via metrology studies that use test parts to characterize statistically
the geometric capabilities of specific AM processes. Towards that end, a test part is designed for
polymer selective laser sintering (SLS) that incorporates an array of geometric features in an
extremely compact volume, such that it can be easily inserted into existing builds. The part is then
built in multiple materials, build orientations, and locations within the build chamber in a factorial-style study to assess the variation attributed to each processing parameter. Both part resolution and
accuracy are investigated. Upon measurement of the test parts, tolerances and design allowables
are established and compiled into a set of design guidelines for SLS. The guidelines are then made
publicly accessible through an online web tool to be used by designers creating parts for polymer
SLS.",,,,,,
"['Nauka, Krzysztof', 'Niu, Michelle', 'Discekici, Emre', 'Hartman, Aja', 'Olubummo, Paul']",2023-01-20T14:03:56Z,2023-01-20T14:03:56Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117255', 'http://dx.doi.org/10.26153/tsw/44136']",eng,2022 International Solid Freeform Fabrication Symposium,Open,ultraviolet light,Powder Bed Fusion of Polymers with Ultraviolet Light Emitting Diode Energy Sources,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ee58827e-bfca-4d4e-a0ba-aec10f8d75ea/download,,"Powder bed 3D printing of polymers often uses broadband near-infrared (NIR) emitters and 
selectively printed fusing agents with absorption spectrum matching the emission of selected IR 
energy source. However, due to few available NIR absorbers that can be formulated into printable 
agent, printed 3D parts often have limited application due to regulatory concerns or unwanted 
color. Shifting the emitter’s spectrum to a narrow, near-ultraviolet band (wavelength > 350 nm) 
can provide more absorber candidates while minimizing the potential UV-induced damage. Choice 
of the printable absorber span from inorganic metal oxides (TiO2, ZnO, CeO, etc.) to organic 
absorbers that may include commercial UV absorbing ingredients used in paints, vitamins, food 
derivatives, cosmetic and pharmaceutical components. Some absorbers, being colorless or white, 
enable printing parts with the original polymer powder color or white base for desired coloring of 
the printed objects.",,,,,,
"['Wang, Jiwen', 'Li, Xiaoxuan', 'Shaw, Leon L.', 'Marcus, Harris L.', 'Cameron, Thomas B.']",2019-10-18T16:55:53Z,2019-10-18T16:55:53Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76260', 'http://dx.doi.org/10.26153/tsw/3349']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Prototyping,Powder Delivery in Dental Restoration Rapid Prototyping Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8116c3e1-fbb8-4ac4-8f90-3794c02202c0/download,,"Rapid prototyping of dental restoration has been investigated for its potential to save time
and cost. In this paper, a powder delivery system was developed to deliver dental porcelain
powder accurately into 2-D shapes for dental restoration. Aqueous suspension of the porcelain
was prepared as the vehicle for the powder delivery. An integrated dry and wet ball-milling
process was developed to reduce the particle size and minimize agglomeration. The reduction in
particle size and minimization of agglomeration increased the suspension stability. The
optimization of the pH value of the suspension also provided an additional means to achieve the
stability and reduce the viscosity of the suspension. With the optimization of the particle size, pH
value and solid concentration in the suspension, desired powder shapes were successfully
delivered.","The authors gratefully acknowledge financial support provided by
the National Science Foundation under Grant No: DMI-9908249",,,,,
"Kumar, Ashok V.",2019-02-19T19:53:51Z,2019-02-19T19:53:51Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73439', 'http://dx.doi.org/10.26153/tsw/591']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'functional structural components']",Powder Deposition and Sintering for a Two-Powder Approach to Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d40894c3-5410-47d3-bb08-a4e6dec8b021/download,,"A two-powder approach is presented where Fused Deposition modeling (FDM) is used to
create a thin shell in the shape of the part to be fabricated. The shell is filled with powder of the
part material and surrounded by a support powder that has a high sintering temperature. Upon
compressing and sintering the shelVpowder system in a uniaxial hot press, the polymer shell burns
out and the support powder compresses the part powder. The part powder consolidates into the
desired part while the support material remains in powder form and can be easily removed. This
paper presents results ofinitial experimental studies.",,,,,,
"['Hossain, M.S.', 'Silva, D.F.', 'Vinel, A.', 'Liu, J.', 'Shamsaei, N.']",2021-12-01T22:42:45Z,2021-12-01T22:42:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90643', 'http://dx.doi.org/10.26153/tsw/17562']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['LB-PBF', 'correlation coefficient', 'variance inflation factor', 'LASSO', 'random forest regression', 'stepwise regression']",Powder Features Affecting Structural and Mechanical Properties of Additively Manufactured Inconel 718: A Machine Learning Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c433f1d-1ef7-4f2f-97cc-65b242030cba/download,University of Texas at Austin,"The aim of this paper is to select important Inconel 718 powder properties that can have
significant effect on the structural and mechanical properties of Laser-Beam Powder Bed Fusion
manufactured specimens. The dataset used was provided by NASA and contains powder
rheological, morphological, and chemical composition properties. The output variables considered
are melt pool depth, high cycle fatigue life, porosity volume fraction and porosity size. Initially,
Pearson correlation coefficient matrix is used to reduce the number of predictor features. Several
statistical and machine learning algorithms including stepwise regression, LASSO, and random
forest regression are used to identify the powder properties that have the strongest impact on the
selected outputs. The variables identified using the different statistical and machine learning
techniques are similar, which increases the confidence of the findings.",,,,,,
"['John Lee, Sang-Joon', 'Sachs, Emanuel', 'Cima, Michael']",2018-05-03T19:18:01Z,2018-05-03T19:18:01Z,1993,Mechanical Engineering,doi:10.15781/T2XD0RF6D,http://hdl.handle.net/2152/65061,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'Department of Materials Science and Engineering', 'Three Dimensional Printing', 'rapid prototyping']",Powder Layer Position Accuracy in Powder-Based Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/31d6cd38-ff8c-4bd1-ac67-85ad75d6a710/download,,,,,,,,
"['Wegner, A.', 'Ünlü, T.']",2021-10-27T22:40:31Z,2021-10-27T22:40:31Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89636,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'aging effects', 'polypropylene', 'processing parameters']",Powder Life Cycle Analyses for a New Polypropylene Laser Sintering Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1667ea16-c7ee-46b6-a61e-e7d2d2258d07/download,University of Texas at Austin,"When processing polymers in laser sintering, material aging occurs. The consequences of
these aging effects are changes of material and part properties. A reduction of surface quality and
the occurrence of orange peel are often found when using a material of too high viscosity. These
effects are well known when processing polyamide 12. For alternative materials there is only
little knowledge on aging effects. Within the presented study effects of material aging and
refreshing for a new developed polypropylene material are analyzed. Viscosity as well as powder
flowability are characterized as material properties. Additionally, part properties in different
orientations are studied for different aging states as well as refreshing levels. Tensile properties
and part density are measured in order to analyze the influence of aging effects on part properties.
Furthermore, the influence of different processing parameters on part quality is studied in order to
establish fundamental process knowledge for the processing of the new polypropylene material.",,,,,,
"['Hu, Q.J.', 'Fuh, J.Y.H.', 'Wong, Y.S.', 'Lu, L.', 'Choy, C.M.', 'Chen, Z.D.']",2019-10-22T18:31:45Z,2019-10-22T18:31:45Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76339', 'http://dx.doi.org/10.26153/tsw/3428']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Metallurgy,Powder Metallurgy of M2 High-Speed Steel for Rapid Tooling Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d6ade62-53ef-40ab-aa5d-8c91d792fb69/download,,"A rapid tooling method has been developed to make a metallic tooling by powder
metallurgy [1]. It is an integration of two techniques: rapid prototyping and powder metallurgy.
The main advantages of this rapid tooling technique over the conventional techniques were short
production cycle, low investment and manufacture costs. The experiment reported was on the
density, microstructure, hardness and shrinkage of M2 high-speed steel parts. The process
included de-binding, sintering and tempering of M2 high-speed steel powder. The material used
was water atomised M2 high-speed steel powder and was sintered in the temperature range of
1270-1310°C for one hour. The process is typically a liquid phase sintering and enables to
obtain high brown densities. After sintering, the micro-structure of the high-speed steel
consisted of 6-12% carbides, 15-30 % austenite and 60-80% martensite, and the parts were to be
tempered. With sintering at 1300°C and tempering, the results showed that 96% density was
obtained, the typical hardness of Hv0.2510 (HRc50) was achieved, the horizontal shrinkage of the
brown part was controlled at 15%±1% and the vertical shrinkage was at 14%±1%. Sintering
above the temperature of 1300°C resulted in increasing of the brown density, rapid growth in
grain size and deformation occurred. Based on the combination of density, shrinkage and
hardness, the optimal sintering temperature and tempering procedure were determined.",,,,,,
"['Majewski, C.E.', 'Horsford, P.M.', 'Hopkinson, N.']",2021-09-29T14:49:37Z,2021-09-29T14:49:37Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88187', 'http://dx.doi.org/10.26153/tsw/15128']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['Elongation at Break', 'Laser Sintered parts', 'thermal pre-conditioning', 'powder pre-conditioning']",Powder Pre-Conditioning for the LS Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/18a490ae-f021-4c8f-9239-d5222583f19e/download,University of Texas at Austin,"It has previously been shown that the use of recycled Nylon-12 powder leads to
increased Elongation at Break (EaB) of Laser Sintered (LS) parts, possibly due to
elevated powder temperature in the part bed causing increases in molecular weight.
However, this increase in EaB often corresponds to a decrease in repeatability, likely
to be through variations in powder history.
The research presented here has shown that thermal pre-conditioning of virgin powder
can increase EaB of LS parts, with no significant loss of repeatability. Materials
analysis of the conditioned powder batches is also presented in order to quantify the
differences in powder properties and to help explain the mechanisms involved.",,,,,,
"['Chen, D.Z.', 'Lao, S.', 'Koo, J.H.', 'Londa, M.', 'Alabdullatif, Z.']",2021-09-30T15:51:40Z,2021-09-30T15:51:40Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88269', 'http://dx.doi.org/10.26153/tsw/15210']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['nano-graphene platelets', 'polyamide 11', 'polymer nanocomposites', 'Selective Laser Sintering', 'powder-powder mixing techniques', 'twin-screw extrusion']",Powder Processing and Properties Characterization of Polyamide 11- Graphene Nanocomposites for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6794958a-32a5-404c-b412-6e937ff3d98b/download,University of Texas at Austin,"Nano-graphene platelets (NGPs) were added to polyamide 11 (PA11) powder in 1%, 3%,
and 5% weight loading in an attempt to create electrostatic dissipative polymer nanocomposites
(PNC) using SLS, a rapid manufacturing process. Powder-powder mixing techniques were
explored as a potential replacement for twin-screw extrusion for dispersing nano-graphene
platelets (NGPs) within a PA11 matrix. The Resodyn™ Resonant Acoustic Mixer as well as the
Thinky™ mixer were studied as powder-powder mixing techniques. After mixing, the powder
samples were pressed into thin-films for characterization on TGA, SEM, four-probe
conductivity, and Raman spectroscopy. TGA results indicate a slight decrease in thermal stability
with the addition of NGPs. This suggests an inadequate dispersion of NGP within the polymer
matrix. SEM images support this hypothesis with evidence of artifacts, a sign of electron
charging, as well as clusters of NGPs. The four-probe conductivity measurements indicate that
all of the samples studied exceed the sensitivity range of the machines used, which is estimated
to be 4.5x1010 Ω/=. This indicates that all of the samples are at least in the upper region of the
range for electrostatic dissipation, if not out of it entirely. Further research will include twin-screw extrusion as well as surface functionalization of NGPs for better dispersion.",,,,,,
"['Soltani-Tehrani, Arash', 'Shamsaei, Nima', 'Surya, Adapa Venkata', 'Mallory, Jaikp', 'Ramakrishnan, Ramesh']",2021-12-06T22:27:15Z,2021-12-06T22:27:15Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90698', 'http://dx.doi.org/10.26153/tsw/17617']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'LB-PBF', 'L-PBF', 'tensile properties', 'Inconel 718', 'powder recycling', 'powder characterization']",Powder Reuse Effects on the Tensile Behavior of Additively Manufactured Inconel 718 Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a028f4a-8e4a-4652-beb6-33c36af76d6f/download,University of Texas at Austin,"Inconel 718 (IN718), with a wide range of applications in aerospace industries and good
weldability, is a popular powder feedstock in the laser beam powder bed fusion (LB-PBF) additive
manufacturing (AM) process. Due to fabrication, handling, and storage costs, powder feedstock is
commonly reused several times. Therefore, it is important to understand how the mechanical
properties of LB-PBF parts can be affected by powder reuse given that powder characteristics may
change after repeated recycling. This study aims to investigate the effect of powder reuse on the
tensile properties of LB-PBF IN718 parts. Powder characteristics such as cohesion and
compressibility will be quantified in order to shed light on the variations observed in the part
performances. In addition, by correlating the state of the reused powder with tensile properties, the
most critical metrics for quality aspects in powder reuse will be determined.",,,,,,
"['Klippstein, Helge', 'Schmid, Hans-Joachim']",2023-01-27T14:20:53Z,2023-01-27T14:20:53Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117338', 'http://dx.doi.org/10.26153/tsw/44219']",eng,2022 International Solid Freeform Fabrication Symposium,Open,laser sintering,Powder Spread Flaws in Polymer Laser Sintering and Its Influences on Mechanical Performance,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df87860b-1766-46d4-acf1-5bf45bf402fc/download,,"By monitoring the recoating process within polymer laser sintering production, it was 
shown that multiple powder-spread-flaws can be detected. Those groove-like flaws are expected 
to be the result of agglomerates jamming between the recoater and the last powder layer. This work 
is analyzing the interaction between powder-spread-flaws and part properties, showing the 
influence of the recoating process on the performance of laser sintering parts. Therefore, artificial 
powder-spread-flaws are applied to the build jobs of tensile test specimens which are measured and 
analyzed regarding the elongation at break, strength and fracture position. For the characteristics 
of the flaws, the artificial grooves are varied in depth and width. Furthermore, the position of the 
flaw is changed form mid part to close to surface areas. It was shown, that several flaws are visible 
at the part surface, resulting in stress concentration and reduced performance. But there are as well 
parts with flaw-layers, which are not visible after the build process on the part. Those parts can 
have significantly reduced mechanical properties as well.",,,,,,
"['Klippstein, Helge', 'Heiny, Florian', 'Pashikanti, Nagaraju', 'Gessler, Monika', 'Schmid, Hans-Joachim']",2021-12-07T18:03:36Z,2021-12-07T18:03:36Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90740', 'http://dx.doi.org/10.26153/tsw/17659']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['powder bed monitoring', 'process monitoring', 'powder spread', 'part properties', 'polymer laser sintering']",Powder Spread Process Monitoring in Polymer Laser Sintering and Its Influences on Part Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f380a29-3310-4df7-8b2a-1c42df4217c5/download,University of Texas at Austin,"Confidence in additive manufacturing technologies is directly related to the predictability of part
properties, which is influenced by several factors. To gain confidence, online process monitoring
with dedicated and reliable feedback is desirable for every process. In this project, a powder bed
monitoring system was developed as a retrofit solution for the EOS P3 laser sintering machines.
A high-resolution camera records each layer, which is analyzed by a Region Based
Convolutional Neural Network (Mask R-CNN). Over 2500 images were annotated and classified
to train the network in detecting defects in the powder bed at a very high level. Each defect is
checked for intersection with exposure areas. To distinguish between acceptable imperfections
and critical defects that lead to part rejection, the impact of these imperfections on part properties
is investigated.",,,,,,
"['Dobson, Sean', 'Vunnam, Swathi', 'Frankel, Dana', 'Sudbrack, Chantal', 'Starr, Thomas']",2021-11-18T00:11:21Z,2021-11-18T00:11:21Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90365', 'http://dx.doi.org/10.26153/tsw/17286']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'additive manufacturing', '17-4 PH stainless steel', 'microstructure', 'mechanical testing']",Powder Variation and Mechanical Properties for SLM 17-4 PH Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/531d061d-2bc7-4d22-bea8-94cc0b4ef2e5/download,University of Texas at Austin,"Chemical composition and atomizing gas of powders may affect properties of 17-4 PH fabricated
via selective laser melting (SLM) process. This study investigates 17-4 PH stainless steel powders
with various atomizing gases and compositions within 17-4 PH specification range. Material
characterization demonstrated differences in flowability between the powders, but all produced
fully dense parts. The as-built phase composition varied widely, with samples from Ar-atomized
powders ranging from a mostly martensitic grain structure to containing a significant amount of
δ-ferrite depending on their composition, whereas samples from N2 atomized powder contained
largely austenite phase. After solutionizing and H900 hardening all Ar atomized powders produced
homogeneous microstructure and improved mechanical properties meeting AMS 17-4 PH
specification. The N2 atomized powder produced a martensitic microstructure with retained
austenite and only ultimate strength meeting AMS specification.",,,,,,
"['Glassshroeder, J.', 'Prager, E.', 'Zaeh, M.F.']",2021-10-13T21:36:39Z,2021-10-13T21:36:39Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88788', 'http://dx.doi.org/10.26153/tsw/15722']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['powder-bed based 3D-printing', '3D printing', 'polymethyl methacrylate', 'PMMA', 'function integrated parts', 'base material', 'additive manufacturing']",Powder-Bed Based 3D-Printing of Function Integrated Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3de6502-2b43-47e1-88cc-db8a5724d7b9/download,University of Texas at Austin,,,,,,,
"['Sutton, Austin T.', 'Kriewall, Caitlin S.', 'Leu, Ming C.', 'Newkirk, Joseph W.']",2021-10-28T14:34:40Z,2021-10-28T14:34:40Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89651,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['powder bed additive manufacturing', 'powder characterization', 'characterization techniques', 'part properties']",Powders for Additive Manufacturing Process: Characterization Techniques and Effects on Part Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1acd25b1-823f-4e27-8bd2-2c2b804070b3/download,University of Texas at Austin,"Powder-bed based Additive Manufacturing is a class of Additive Manufacturing (AM)
processes that bond successive layers of powder by laser melting to facilitate the creation of parts
with complex geometries. As AM technology transitions from the fabrication of prototypes to
end-use parts, the understanding of the powder properties needed to reliably produce parts of
acceptable quality becomes critical. Consequently, this has led to the use of powder
characterization techniques such as scanning electron microscopy (SEM), laser light diffraction,
x-ray photoelectron spectroscopy (XPS), and differential thermal analysis (DTA) to both
qualitatively and quantitatively study the effect of powder characteristics on part properties.
Utilization of these powder characterization methods to study particle size and morphology,
chemical composition, and microstructure of powder has resulted in significant strides being
made towards the optimization of powder properties for powder-bed based AM processes. This
paper reviews methods commonly used in characterizing metallic AM powders, and the effects
of powder characteristics on the part properties in these AM processes.",,,,,,
"['Jacobson, D. M.', 'Bennett, G.']",2020-03-05T20:08:27Z,2020-03-05T20:08:27Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80155', 'http://dx.doi.org/10.26153/tsw/7176']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Direct Metal Laser Sintering,Practical Issues in the Application of Direct Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/118f6c81-e1d1-4ee4-ac64-033c7957ee7c/download,,"Direct Metal Laser Sintering (DMLS) was introduced to meet the objective of producing
metal parts directly from CAD data. CRDM has accumulated six years of experience in
applying this technique, mostly to prototyping parts for evaluation. For some applications,
such as blow moulds, porosity generated in DMLS has proved to be beneficial, but for others
a concession on tolerances or finish are necessary and/or complementary operations are
required, which add to manufacturing time and cost. This paper examines such issues
through some well chosen examples of parts to demonstrate both the strengths and
weaknesses of the DMLS process.",,,,,,
"['Klosterman, Don', 'Chartoff, Richard', 'Osborne, Nora', 'Graves, George', 'Lightman, Allan', 'Steidlel, Cheri']",2018-11-30T14:57:09Z,2018-11-30T14:57:09Z,1997,Mechanical Engineering,doi:10.15781/T2C53FM75,http://hdl.handle.net/2152/70590,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Material Selection', 'Rapid Prototype']","Pre-LOM, LOM, and Post-LOM Processes for the Fabrication of SiC and SiC/SiC Components",Conference paper,https://repositories.lib.utexas.edu//bitstreams/34b81d00-7cc0-4d87-a883-04fc2f747693/download,,,,,,,,
"['Roschli, Alex', 'Post, Brian K.', 'Chesser, Phillip C.', 'Sallas, Matt', 'Love, Lonnie J.', 'Gaul, Katherine T.']",2021-11-09T19:20:54Z,2021-11-09T19:20:54Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90140', 'http://dx.doi.org/10.26153/tsw/17061']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['precast concrete molds', 'big area additive manufacturing', 'conventional pattern making']",Precast Concrete Models Fabricated with Big Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/825ed515-8424-4d4d-8d0f-fd59b97acc7d/download,University of Texas at Austin,"The traditional process of making precast concrete molds requires significant manual
labor. The molds are made using hardwood, cost tens of thousands of dollars, and take weeks to
build. Once built, a mold will last 5-10 pulls before becoming too heavily degraded to continue
use. With additive manufacturing, the same mold can be built in eight hours, post-machined in
eight hours, costs about $9000, and is projected to last nearly 200 pulls. Oak Ridge National
Laboratory has been working with Big Area Additive Manufacturing (BAAM) to fabricate
concrete molds for a new high-rise apartment complex in New York. The molded pieces will
form structural window supports for the hundreds of windows in building façade. The magnitude
of window molds is where additive manufacturing can shine when producing the geometry. This
paper will discuss the methods and findings of using BAAM to replace conventional precast
concrete pattern making.",,,,,,
"['Jean, Daniel L.', 'Duty, Chad E.', 'Fuhrman, Brian T.', 'Lackey, W. Jack']",2019-09-20T18:13:15Z,2019-09-20T18:13:15Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75922', 'http://dx.doi.org/10.26153/tsw/3021']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Deposition,Precision Carbon Deposition Using Pyrolytic Laser Chemical Vapor Deposition (LCVD) 73,Conference paper,https://repositories.lib.utexas.edu//bitstreams/09ab4a89-e6a2-489f-af3b-06e5c65a4a9f/download,,"Laser Chemical Vapor Deposition (LCVD) can be used to rapid prototype many different metals and ceramics. The spatial resolution is potentially very fine, depending on the accuracy of stage or laser movement, and the size of the laser spot used for the localized heating. This paper describes a set of experiments performed using an LCVD system powered with a 100 Watt CO2 laser. The laser was focused to 200 mm onto a graphite substrate to deposit pyrolytic carbon. The morphologies of the carbon deposits were studied while varying laser power, reagent concentration, scanning speeds, and scanning patterns.",,,,,,
"['Li, L.', 'McGuan, R.', 'Kavehpour, P.', 'Candler, R.N.']",2021-11-09T15:22:00Z,2021-11-09T15:22:00Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90092', 'http://dx.doi.org/10.26153/tsw/17013']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['metrology', 'additive manufacturing', 'high-speed optical scanning', 'in situ validation', 'scan while printing', 'geometric dimensioning and tolerating']",Precision Enhancement of 3D Printing via In Situ Metrology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9106a313-7ec3-4653-81ce-17e29fa75764/download,University of Texas at Austin,"The field of additive manufacturing, especially 3D printing, has gained growing attention in the research
and commercial sectors in recent years. Notwithstanding that the capabilities of 3D printing have moved on to
enhanced resolution, higher deposition rate, and a wide variety of materials, the crucial challenge of verifying
that the component manufactured is within the dimensional tolerance as designed continues to exist. This work
developed and demonstrated an approach for layer-by-layer mapping of 3D printed parts, which can be used for
validation of printed models and in situ adjustment of print parameters. A high-speed optical scanning system
was integrated with a Fused Deposition Modeling type 3D printer to scan during the print process on demands.",,,,,,
"['Wang, F.', 'Shor, L.', 'Darling, A.', 'Khalil, S.', 'Sun, W.', 'Güçeri, S.', 'Lau, A.']",2019-11-21T18:35:35Z,2019-11-21T18:35:35Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78562', 'http://dx.doi.org/10.26153/tsw/5618']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Poly-e-Caprolactone,Precision Extruding Deposition and Characterization of Cellular Poly-e-Caprolactone Tissue Scaffolds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/01596c97-57bc-4ff4-b2e3-662bf721f5dd/download,,"Successes in scaffold guided tissue engineering require scaffolds to have specific macroscopic
geometries and internal architectures in order to provide the needed biological and biophysical
functions. Freeform fabrication provides an effective process tool to manufacture many advanced
scaffolds with designed properties. This paper reports our recent study on using a novel Precision
Extruding Deposition (PED) process technique to directly fabricate cellular Poly-ε-Caprolactone
(PCL) scaffolds. Scaffolds with a controlled pore size of 250 µm and designed structural
orientations were fabricated. The scaffold morphology, internal micro-architecture and
mechanical properties were evaluated using SEM, Micro-Computed Tomography (µ-CT) and the
mechanical testing. Preliminary biological study was also conducted to investigate the cell
responses to the as-fabricated tissue scaffolds. The results and the characterizations demonstrate
the viability of the PED process to the scaffold fabrication as well as a good mechanical
property, structural integrity, controlled pore size, pore interconnectivity, and the anticipated
biological compatibility of the as-fabricated PCL scaffolds.","The authors acknowledge the NSF-0219176 project funding support to graduate students
Andrew Darling and Saif Khalil, and the ONR research funding support to graduate student
Lauren Shor.",,,,,
"['Shor, L.', 'Güçeri, S.', 'Sun, W.']",2020-02-27T20:11:25Z,2020-02-27T20:11:25Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80099', 'http://dx.doi.org/10.26153/tsw/7120']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Precision Extrusion Deposition,Precision Extrusion Deposition of Polycaprolactone/Hydroxyapatite Tissue Scaffolds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9f9ddb22-d16a-4d7f-b2c9-884c884714a8/download,,"Freeform fabrication provides an effective process tool to manufacture advanced tissue scaffolds
with specific designed properties. Our research focuses on using a novel Precision Extrusion
Deposition (PED) process technique to directly fabricate Polycaprolactone (PCL) and composite
PCL/ Hydroxyapatite (HA) tissue scaffolds. The scaffold morphology and the mechanical
properties were evaluated using SEM and mechanical testing. In vitro biological studies were
conducted to investigate the cellular responses of the composite scaffolds. Results and
characterizations demonstrate the viability of the PED process as well as the good mechanical
property, structural integrity, controlled pore size, pore interconnectivity, and the biological
compatibility of the fabricated scaffolds.",,,,,,
"['Jean, Daniel L.', 'Duty, Chad E.', 'Fuhrman, Brian T.', 'Lackey, W. Jack']",2019-03-08T17:47:07Z,2019-03-08T17:47:07Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73572', 'http://dx.doi.org/10.26153/tsw/714']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['LCVD', 'materials']",Precision LCVD System Design with Real Time Process Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9cab3350-dfe2-4c15-9e3c-202f0e25d526/download,,"A Laser Chemical Vapor Deposition (LCVD) system was designed using a fixed 100
Watt C02 laser focused on a moveable substrate. Temperature and height measurement devices
monitor the reaction at the point of deposition to provide feedback for controlling the process.
The LCVD system will use rapid prototyping technology to directly fabricate fully threedimensional ceramic, metallic, and composite parts of arbitrary shape. Potential applications
include high temperature structures, electronic/photonic devices, and orthopaedic implants.",,,,,,
"['Chadha, Charul', 'Patternson, Albert E.', 'Jasiuk, Iwona']",2021-12-01T23:32:39Z,2021-12-01T23:32:39Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90657', 'http://dx.doi.org/10.26153/tsw/17576']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['part repair', 'adhesive strength', 'thermoplastics', 'polymer healing theory', 'fused filament fabrication']",Predict Adhesive Strength of Repair of Thermoplastic Component Based on Polymer Healing Theory,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d7a47ff9-4220-492f-80e5-1f2e646dd671/download,University of Texas at Austin,"Advancements in polymer technology have increased the production of high-valued parts using
polymers. These parts are often produced in low volumes and have complex geometries, making
them difficult to reproduce later, especially when original tooling is no longer available.
Reproduction of these parts from scratch using additive manufacturing (AM) can be time-consuming and, at times, economically infeasible. This paper explores the application of fused
filament fabrication (FFF-extrusion-based AM) to repair such parts and print broken features on
damaged parts. Polymer healing theory is then employed to understand the effect of print speed on
adhesive strength at the interface formed between the 3D printed repair geometry and the original
damaged part. The theory was verified using three-point bending experiments. Results show that
the adhesive strength at the interface is approximately proportional to print speed raised to power
negative one-fifth fraction.",,,,,,
"['Crockett, R.S.', ""O'Kelly, J."", 'Calvert, P.D.', 'Fabes, B.D.', 'Stuffle, K.', 'Creegan, P.', 'Hoffman, R.']",2018-10-03T19:32:24Z,2018-10-03T19:32:24Z,1995,Mechanical Engineering,doi:10.15781/T2833NH66,http://hdl.handle.net/2152/68683,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['polymerization', 'advanced ceramics research', 'CAD']",Predicting and Controlling Resolution and Surface Finish of Ceramic Objects Produced by Stereodeposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a1955181-4195-4051-af4c-99660961190d/download,,"Stereodeposition techniques are well suited for the Solid Freeform Fabrication of dense ceramic
components. As opposed to forming a pattern in a particle bed or polymer bath, stereodeposition
processes deposit material directly onto the previously created layer. The key to stereodeposition is
a material's ability to be dispensed as a fluid, yet rapidly stiffen to hold the shape of the object.
This is accomplished by either solidification of a thermoplastic binder upon cooling from a melt
(Fused Deposition) or by polymerization of a binder (Reactive Stereodeposition). We are
developing both techniques for the production of functional ceramic and engineering polymer
objects.
A key issue in developing a successful stereodeposition system is controlling the rate of bead
transformation from liquid to solid. Control is critical to achieving high resolution and low surface
roughness of the finished product, but is made complex by the large number of parameters
involved. These include binder parameters (surface tension, gelling characteristics), slurry
parameters (viscosity, particle loading and size distribution), and process parameters (deposition
rate, temperature). Current efforts at the University of Arizona are focused on modeling and
controlling the deposition and transformation of ceramic slurries used in the Reactive
Stereodeposition process.",,,,,,
"['Merschroth, Holger', 'Kniepkamp, Michael', 'Weigold, Matthias']",2021-11-16T16:07:30Z,2021-11-16T16:07:30Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90327', 'http://dx.doi.org/10.26153/tsw/17248']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['neural networks', 'thermal history', 'temperature prediction', 'temperature control', 'laser power', 'laser-based powder bed fusion']",Predicting and Controlling the Thermal Part History in Powder Bed Fusion Using Neural Networks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/596e094e-1370-4878-9f83-35d4f0279666/download,University of Texas at Austin,"Laser-based powder bed fusion of metallic parts is used widely in different branches of
industry. Although there have been many investigations to improve the process stability, thermal
history is rarely taken into account. The thermal history describes the parts’ thermal situation
throughout the build process as a result of successive heating and cooling with each layer. This
could lead to different microstructures due to different thermal boundary conditions. In this paper,
a methodology based on neural networks is developed to predict and control the parts’ temperature
by adjusting the laser power. A thermal imaging system is used to monitor the thermal history and
to generate a training data set for the neural network. The trained network is then used to predict
and control the parts temperature. Finally, tensile testing is conducted to investigate the influence
of the adjusted process on the mechanical properties of the parts.",,,,,,
"['Kishore, Vidya', 'Ajinjeru, Christine', 'Liu, Peng', 'Lindahl, John', 'Hassen, Ahmed', 'Kunc, Vlastimil', 'Duty, Chad']",2021-11-04T14:50:06Z,2021-11-04T14:50:06Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89975,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['sharkskin instability', 'sharksin', 'reinforced thermoplastics', 'extrusion additive manufacturing', 'big area additive manufacturing']",Predicting Sharkskin Instability in Extrusion Additive Manufacturing of Reinforced Thermoplastics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f5b89d5e-eb9d-4c26-9ced-a10d8e7f2270/download,University of Texas at Austin,"The development of large scale extrusion additive manufacturing systems such as the Big
Area Additive Manufacturing (BAAM) system has enabled faster printing with throughput as high
as 50 kg/h and the use of a variety of thermoplastics and composites with filler loading as high as
50%. The combination of high throughput and heavy reinforcements can give rise to a
phenomenon known as “sharkskin” instability, which refers to extrudate surface distortions
typically in the form of roughness or mattness, and is commonly observed in traditional extrusion
processes. The onset of this instability depends upon the viscoelastic properties of the material and
processing parameters such as throughput, shear rate, extruder die geometry, and temperature. For
printed parts, such instabilities are undesirable and detrimental to mechanical properties. This work
examines the effect of process parameters on the rheological properties of BAAM thermoplastics
and composites to predict the occurrence of sharkskin during printing.",,,,,,
"['Bartolai, Joseph', 'Simpson, Timothy W.', 'Xie, Renxuan']",2021-10-28T14:18:23Z,2021-10-28T14:18:23Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89646,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['thermoplastic polymer', 'temperature history', 'rheological data', 'welding theory', 'mechanical strength', 'fused filament fabrication']",Predicting Strength of Thermoplastic Polymer Parts Produced Using Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb496cc7-8b56-45b4-90e9-2b8646a9c46c/download,University of Texas at Austin,"The weakest point in polymer parts produced by Fused Filament Fabrication (FFF) is the
interface between adjacent layers and deposition toolpaths, or “roads”. We introduce a novel
approach that uses the temperature history of these interfaces, polymer rheological data, and
polymer welding theory to predict the mechanical strength of parts subjected to uniaxial tension.
Interface temperature history data is collected in-situ using infrared imaging. Rheological data
of the polycarbonate (PC) used to fabricate the parts in this study was determined
experimentally. The prediction of strength of the interfaces was performed using polymer weld
theory from the literature adapted to the PC feedstock used in this study. Understanding how the
strength of the road and layer interfaces develop mechanical strength will lead to stronger FFF
parts through intelligent toolpath optimization and temperature control.",,,,,,
"['Peng, B.', 'Panesar, A.']",2024-03-26T20:12:23Z,2024-03-26T20:12:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124389', 'https://doi.org/10.26153/tsw/50997']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['PINN', 'metal additive manufacturing', 'temperature field']",Predicting Temperature Field for Metal Additive Manufacturing using PINN,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bcd4f7b0-f922-4b28-ae01-954e237bfe79/download,University of Texas at Austin,"Machine-learning-based methods are gaining traction as an alternative to numerical
methods in many engineering applications. Physics-informed neural network (PINN), a self-supervised method, is particularly attractive with its unique capability of guiding the training
with physical laws written in the forms of partial differential equations. Thermomechanical
simulation for additive manufacturing (AM), a multi-scale, multi-physics problem could
potentially benefit from the use of PINN, as demonstrated in some successful attempts in the
literature. In this work, PINN is applied to different metal AM processes and several challenges
that limit the robustness of PINN are observed. This paper aims to provide a summary of the
observations and a preliminary attempt to account for such observations in order to pave the
path for future work that aims to unleash the full promise of PINN in AM-related applications.",,,,,,
"['Yadollahi, Aref', 'Mahtabi, Mohammad J.', 'Doude, Haley R.', 'Newman, James C. Jr']",2021-11-02T13:35:51Z,2021-11-02T13:35:51Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89798,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'AM', 'laser powder bed fusion', 'L-PBF', 'fatigue-life prediction', 'crack growth', 'FASTRAN']",Prediction of Fatigue Lives in Additively Manufactured Alloys Based on the Crack-Growth Concept,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea52d9ee-d75b-43fd-a36a-709b137a60d1/download,University of Texas at Austin,"This paper aims to predict the fatigue behavior of additively manufactured alloys using crack-growth data. Among different sources of damage under cyclic loadings, fatigue due to cracks
originated from voids is the most life-limiting failure mechanism in powder-based metal additive
manufacturing (AM) parts. Hence, the ability to predict the fatigue behavior of AM materials based
on the void features is the first step toward improving AM part reliability. Test results from the
literature on AM alloys are analyzed herein to model fatigue behavior based on the semi-circular
surface flaws. The fatigue-life variations in the specimens are captured using the distribution of
defect size. The results indicate that knowing the statistical distribution of the defect size can
provide the opportunity of predicting the scatter in the fatigue-life of the AM materials, using an
appropriate fatigue analysis code.",,,,,,
"['Pal, Deepankar', 'Patil, Nachiket', 'Stucker, Brent E.']",2021-10-06T20:24:12Z,2021-10-06T20:24:12Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88433', 'http://dx.doi.org/10.26153/tsw/15370']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'Ti6Al4V', 'dislocation density based crystal plasticity framework', 'DDCP-FEM']",Prediction of Mechanical Properties of Electron Beam Melted Ti6Al4V Parts Using Dislocation Density Based Crystal Plasticity Framework,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6440965b-6508-4cc3-8af3-2b0ca0f6a7d8/download,University of Texas at Austin,"Parts produced using Electron Beam Melting (EBM) with Ti6Al4V powders are
generally tested for two important mechanical properties, namely tensile strength and fatigue life.
The optimization of the process input parameters, such as part orientation, initial powder size and
hatch pattern, for the abovementioned mechanical properties has been attempted using two
numerical finite element methods. First, the dislocation density based crystal plasticity
framework (DDCP-FEM) has been used to evaluate the localized stress-strain evolution,
dislocation density evolutions and non-local deformations as a function of loading, sample
geometry, microstructural phase, grain size and shape. This analysis has been compared against
simulations based on continuum plasticity based finite element techniques. Though the localized
evolutions as a function of microstructural attributes are missing in the continuum analysis, the
low computational costs involved makes this technique an ideal candidate for spatial
homogenization of the DDCP-FEM framework. The simulations conducted in the current work
only validate the mechanical properties for tensile and fatigue specimens fabricated with known
process parameters. These simulations will form the basis for future modeling efforts to
optimize these parameters for required mechanical properties in service.",,,,,,
"['Nasirov, A.', 'Hasanov, S.', 'Fidan, I.']",2021-11-18T17:49:40Z,2021-11-18T17:49:40Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90446', 'http://dx.doi.org/10.26153/tsw/17367']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['classical laminate theory', 'multiscale modeling', 'mechanical properties', 'fused deposition modeling']",Prediction of Mechanical Properties of Fused Deposition Modeling Made Parts using Multiscale Modeling and Classical Laminate Theory,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e52a5ab-6bc4-4bad-bf59-7e129d349bef/download,University of Texas at Austin,"Fused deposition modeling (FDM) is one of the most popular additive manufacturing (AM)
processes that works based on the layer-by-layer buildup of a 3D modeled part from polymers or
fiber-reinforced polymer materials. In recent years, extensive research has been done to
characterize the mechanical properties of FDM produced parts using classical laminate theory
(CLT). However, considering the limitation of micromechanics approach to simple unit cells, there
is a need to explore different techniques to alleviate those limitations. Taking into account the
periodicity and multiscale nature of FDM infill patterns, one such technique is the asymptotic
homogenization method used in this study to find mechanical properties. Moreover, the input of
homogenized properties in CLT is discussed. Finally, both homogenization and CLT results are
compared with experimental results.",,,,,,
"['Klingbeil, N.W.', 'Brown, C.J.', 'Bontha, S.', 'Kobryn, P.A.', 'Fraser, H.L.']",2019-10-22T18:24:58Z,2019-10-22T18:24:58Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76336', 'http://dx.doi.org/10.26153/tsw/3425']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Deposition,Prediction of Microstructure in Laser Deposition of Titanium Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/618984dc-95a3-4339-8014-3e68ffd6331a/download,,"Laser deposition of titanium alloys is under consideration for aerospace applications, and
offers significant increases in efficiency and flexibility compared to conventional manufacturing
methods. However, its ultimate success will depend on the ability to predict and control the
microstructure and resulting mechanical properties of the deposit. In this study, both 2-D
continuum finite element modeling and 3-D cellular automaton finite element modeling of a thinwall geometry are used to investigate the effects of deposition process variables on microstructure
in laser deposited Ti-6Al-4V. Numerical results for cooling rate and thermal gradient obtained from
the 2-D models are used to provide insight into grain size and morphology, while the 3-D cellular
automaton models are used to provide direct predictions of deposited microstructure. The
numerical model predictions are subsequently compared with observed microstructures in LENSTM
deposited Ti-6Al-4V.","This work was supported by the Joint AFRL/DAGSI Research Program, project number
ML-WSU-01-11, as well as by a grant from Wright State University and the Ohio Board of
Regents.",,,,,
"['Tapia, G.', 'Elwany, A.H.']",2021-10-21T18:00:04Z,2021-10-21T18:00:04Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89412,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['predictive models', 'porosity', 'Selective Laser Melting', 'Multivariate Adaptive Regression Splines']",Prediction of Porosity in SLM Parts Using a MARS Statistical Model and Bayesian Inference,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dfe7c9fb-77e4-48e6-9669-b5d8653f97ca/download,University of Texas at Austin,"Predictive models that establish a linkage between process parameters and part properties
have been identified as a high priority research need in Additive Manufacturing. We work with
a Multivariate Adaptive Regression Splines (MARS) statistical model to predict the porosity of
parts produced using Selective Laser Melting (SLM) process as a function of process parameters. The proposed predictive model is validated through a case study on 17-4 PH stainless
steel test coupons manufactured on a ProX 100 SLM system.",,,,,,
"['Karamooz-Ravari, M.R.', 'Taheri Andani, M.']",2021-11-04T18:59:21Z,2021-11-04T18:59:21Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90005', 'http://dx.doi.org/10.26153/16926']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['finite element method', 'TPMS', 'elastic response', 'cellular lattice structures', 'P-type', 'G-Type']",Prediction of the Elastic Response of TPMS Cellular Lattice Structures Using Finite Element Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/190a5e4d-379f-4f19-a4eb-d0c8ad9bc463/download,University of Texas at Austin,"Cellular lattice structures are a group of porous materials in which the cells are regularly
distributed. Since the morphology of the cells is complicated, the fabrication of them is challenging
using conventional methods. However, with the advent of additive manufacturing technology,
more attention is focused on these classes of materials because the regular geometry makes it
possible to tailor the mechanical response of the structure. Among all kinds of cellular lattice
structures, those based on triply periodic minimal surfaces are of great importance due to
mechanical and biological properties. Since the fabrication of such structures is challenging and
expensive, it is desirable to predict their mechanical response before fabrication. In this paper,
finite element approach is employed to predict the elastic response of two well-known Schwarz
minimal surfaces named P-Type and G-Type. To do so, first, the cloud points of the surfaces are
generated using the implicit equation of the surface and are converted into solid finite element
models. The results show that at the same value of porosity, the P-Type specimen provides a higher
value of elastic modulus than G-Type one.",,,,,,
"['Badrinarayan, B.', 'Barlow, J.W.']",2018-04-10T18:19:59Z,2018-04-10T18:19:59Z,1990,Mechanical Engineering,doi:10.15781/T2FT8F24M,http://hdl.handle.net/2152/64244,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'Selective Layer Sintering', 'SLS']",Prediction of the Thermal Conductivity of Beds Which Contain Polymer Coated Metal Particles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f5a9391f-bd56-49a5-94c2-0a009af7a97e/download,,"Structural parts of ceramics or metals can, in principle, be made by laser sintering
polymer coated ceramic or metal powders, followed by conventional methods for removing
the binder and sintering in ovens. Understanding the laser sintering of coated materials
requires knowledge of the behavior of beds containing composite particles. Many
correlations for predicting the effective thermal conductivity of a bed of solid particles exist
in literature, but little work has been done on beds of coated particles. We coated lead
shots(high conductivity) with a styrene acrylic acid copolymer (low conductivity) to study
the effect of coating thickness on the thermal conductivity. The thermal conductivity ofthe
coated particle·hed was found to •drop rapidly in the beginning·· and then level off with
increasing coating thickness. We also developed an equation that yields the equivalent
conductivity of a coated spherical particle subjected to axial heat flow. The predicted results
with the experimental measurements of bed conductivity obtained by an unsteady
state method.",,,,,,
"['Sih, Samuel Sumin', 'Barlow, Joel W.']",2018-11-08T15:23:40Z,2018-11-08T15:23:40Z,1995,Mechanical Engineering,doi:10.15781/T2ZW19C17,http://hdl.handle.net/2152/69887,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'heat transfer', 'Powder beds']",The Prediction of the Thermal Conductivity of Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1f6eb687-8fdf-47df-abf4-3daa466f9e20/download,,"A revised view factor for the prediction of the thermal conductivity of powder beds at high
temperatures that includes a radiation contribution to the conductivity is presented.
Comparison of predictions by this equation with 424 measured values shows the
predictions to be accurate to within a ±30% relative error.",,,,,,
"['Nettekoven, A.', 'Fish, S.', 'Topcu, U.', 'Beaman, J.']",2021-11-16T15:02:24Z,2021-11-16T15:02:24Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90305', 'http://dx.doi.org/10.26153/tsw/17226']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'iterative learning control', 'machine learning', 'intelligent control', 'artificial intelligence']",Predictive Iterative Learning Control with Data-Driven Model for Optimal Laser Power in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/01599a8e-73d1-4970-9e86-79bc71858b32/download,University of Texas at Austin,"Building high quality parts is still a key challenge for Selective Laser Sintering machines
today due to a lack of sufficient process control. In order to improve process control, we propose
a Predictive Iterative Learning Control (PILC) controller that minimizes the deviation of the postsintering temperature profile of a newly scanned part from a desired temperature. The controller
does this by finding an optimal laser power profile and applying it to the plant in a feedforward
manner. The PILC controller leverages machine learning models that accurately capture the
process’ temperature dynamics based on in-situ measurement data while still guaranteeing low
computational cost. We demonstrate the controller’s performance in regards to the control
objective with heat transfer simulations by comparing the PILC-controlled laser power profiles to
constant laser power profiles.",,,,,,
,2019-09-25T15:54:41Z,2019-09-25T15:54:41Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/75998', 'http://dx.doi.org/10.26153/tsw/3097']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Preface,Preface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e056690-14ae-4493-a7f0-3004de57a050/download,,,,,,,,
Laboratory for Freeform Fabrication and University of Texas at Austin,2023-01-19T17:33:19Z,2023-01-19T17:33:19Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117248', 'http://dx.doi.org/10.26153/tsw/44129']",eng,2022 International Solid Freeform Fabrication Symposium,Open,preface,Preface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1deb22c5-82b1-4b83-87c9-f4cd2a021472/download,,,,,,,,
"['Dai, K.', 'Shaw, L.']",2019-10-24T17:56:37Z,2019-10-24T17:56:37Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77410', 'http://dx.doi.org/10.26153/tsw/4499']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Densification,Preheating Effects on Multiple Material Laser Densification,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e3e2522-f98a-4cfa-8e4b-9d04b9022317/download,,"A 3-dimensional thermomechanical model has been developed to study laser powder
densification of multiple materials in the multi-materials laser densification (MMLD) process.
Thermal and mechanical properties of the materials are porosity- and temperature-dependent. In
particular, the effect of the chamber preheating on residual stresses and warping of the part
fabricated has been investigated. It is found that the chamber preheating can reduce warping and
residual stresses of the laser-processed part. Furthermore, the extent of the preheating effect
depends on the laser-scanning pattern. Implications of the simulation result on MMLD have been
discussed.","The authors gratefully acknowledge financial support provided by
the National Science Foundation under Grant No: DMI-9908249.",,,,,
"['Saint John, David B.', 'Joshi, Sanjay B.', 'Simpson, Timothy W.', 'Qu, Meng', 'Rowatt, John David', 'Lou, Yucun']",2021-10-26T20:21:52Z,2021-10-26T20:21:52Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89576,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser-based powder bed fusion', 'additive manufacturing', 'Inconel 718', 'feedstock powders', 'build location', 'variability']",A Preliminary Examination of Variability Due to Build Location and Powder Feedstock in Additive Manufacture of Inconel 718 using Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/40e8a042-28a1-42e6-b7f6-1698585c81ec/download,University of Texas at Austin,"The production of metallic parts by additive manufacturing (AM) is of significant interest
to industry, but in the absence of standards, practical design considerations for manufacturing
engineers are not widely known. Within the context of powder bed fusion (PBF), many
unknowns persist regarding variations in part quality due to part location on the build plate,
process consistency, feedstock supplier, and machine manufacturer. In this paper, we investigate
the mechanical property variance across the build platform and document the successful use of
feedstock powders obtained from several suppliers for the manufacture of Inconel 718 tensile
and Charpy specimens, built on an EOS M280 laser-based powder bed fusion system. Particular
emphasis is placed on describing the manufacturing process design challenges encountered even
for simple geometries. While many advocate that complexity is free when using AM, we find
that AM can lead to expensive build failures given the current state of manufacturing process
knowledge and that design for additive manufacture is required for successful application of AM
techniques.",,,,,,
"['Levy, Richard A.', 'Guduri, Sashidhar', 'Crawford, Richard H.']",2018-04-19T18:02:18Z,2018-04-19T18:02:18Z,1992,Mechanical Engineering,doi:10.15781/T2NK36N7B,http://hdl.handle.net/2152/64396,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'computed tomographic data', 'CT data', 'Department of Mechanical Engineering', 'Department of Radiology']",Preliminary Experience with Selective Laser Sintigrapbic (SLS) Models of the Human Temporal Bone,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ff1f7819-d86f-4401-aaa3-25070f1140c7/download,,"To assess the accuracy of three-dimensional models of the human temporal bone
generated from computed tomographic (CT) data.",,,,,,
"['Kumar, Pranav', 'Beck, Elizabeth', 'Das, Suman']",2019-11-15T16:20:58Z,2019-11-15T16:20:58Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78421', 'http://dx.doi.org/10.26153/tsw/5508']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Preliminary,Preliminary Investigations on the Deposition of Fine Powders Through Miniature Hopper-Nozzles Applied to Multi-Material Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/630ff6b0-6dce-46a1-ac23-fa0a34b0276a/download,,"A concept for multi-material solid freeform fabrication is proposed to enable the fabrication of
heterogeneous components. This concept features nozzles designed for depositing thin layers of multiple
patterned materials followed by selective laser sintering for consolidation to desired densities. Although
prior work on the design of small-scale nozzles for powder delivery is lacking, our design is guided by
background theory for particle flow through hoppers. Experimental guidelines for the delivery of powders
with particle sizes in the 10-125µm range through hopper-nozzle orifices with diameters in the 0.5-2mm
range are presented. This is a preliminary investigation of particle flow behavior necessary for continuous
mass flow rates under gravity, low gas pressure-assisted flow, and vibration-assisted flow conditions. As
proof of concept, several patterned beds of single and multiple materials were deposited on an X-Y table.
A simple model to predict the linewidth of lines deposited by gravity flow is presented.",,,,,,
"['Niino, T.', 'Yamada, H.', 'Seki, S.']",2020-02-13T19:21:16Z,2020-02-13T19:21:16Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79964', 'http://dx.doi.org/10.26153/tsw/6989']",eng,2004 International Solid Freeform Fabrication Symposium,Open,stereolithography,Preliminary Study for Transparentization of SLS Parts by Resin Infiltration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a1c94be4-a646-40bb-ba65-2825450566e3/download,,"Since opacity of SLS processed parts are derived from random reflection and refraction at
boundaries of refractive indices between the air and plastic, infiltration of resin that shares the
same index with the plastic can increase transparency of the parts. In this paper, desirable
characteristics for the infiltrant were investigated first, and transparentization test of SLS
processed parts out of CastFormTM was carried out. The highest transmittance of 80% and the
lowest haze of 55% were obtained. However, exact match of refractive indices of powder for SLS
and infiltrant did not give the best transparency. The reasons were considered in discussions.",,,,,,
"['Miyanaji, Hadi', 'Yang, Li', 'Zhang, Shanshan', 'Zandinejad, Amirali']",2021-10-13T20:04:11Z,2021-10-13T20:04:11Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88774', 'http://dx.doi.org/10.26153/tsw/15708']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['dental porcelain', 'aluminous porcelain', 'graded structure', '3D printing']",A Preliminary Study of the Graded Dental Porcelain Ceramic Structures Fabricated via Binder Jetting 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93f84829-aca1-46f3-9af9-1851b8869b6b/download,University of Texas at Austin,"Dental porcelain is a common material used for various dental restoration structures
including crowns, bridges and veneers. However, the current designs of all-ceramic
porcelain restorations lack sufficient mechanical property controls, which results in
increased failure rates. In this study, dental porcelain ceramics with graded
compositions were fabricated by binder jetting 3D printing system in the attempt to
actively control their mechanical performance. The graded structures were produced
by two different fabrication routes, which are lamination stacking and continuous
fabrication. In the lamination stacking route, porcelain laminates with different
compositions were fabricated individually and stacked up for the sintering to form
integrated structures with graded properties. In the continuous fabrication, samples
with graded structure were printed continuously in the 3D printing machine.
Microstructural evaluations with the samples demonstrated the feasibility of
achieving good structural integrity for the dental porcelain parts fabricated by the
continuous method.",,,,,,
"['Fei, Guanghai', 'Wei, Tiwei', 'Shi, Qimin', 'Guo, Yongjian', 'Oprins, Herman', 'Yang, Shoufeng']",2021-11-30T20:29:15Z,2021-11-30T20:29:15Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90537', 'http://dx.doi.org/10.26153/tsw/17456']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['hybrid manufacturing', 'electronics devices', 'stereolithography', 'adhesion', 'thermal reliability']",Preliminary Study on Hybrid Manufacturing of the Electronic-Mechanical Integrated Systems (EMIS) via the LCD Stereolithography Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c8c147ce-d701-4882-bde8-ccef83a41d95/download,University of Texas at Austin,"Compared to limited complexity capacity in traditional fabrication and assembly techniques, Additive
Manufacturing (AM)-based hybrid fabrication is emerging in electronics industry for fabricating complex
structures and simplifying the assembly steps. In this study, the fabrication process of the Electronic-Mechanical
Integrated Systems (EMIS) is investigated, in which mechanical parts (gas/liquid chambers) were 3D printed
directly on PCB substrate (the carrier of electronic devices). A mixture of resin with silica was used as printing
feedstock, to reduce mismatch of thermal expansion coefficient (CTE) between the part and PCB. The silica
loading of 60 vol% was appropriate to achieve a compromise between viscosity of the suspension and CTE.
Adhesion forces between printed parts and PCBs were measured, showing a significant correlation with the PCB
surface roughness. Thermal cycling test indicated that the tailored materials owned excellent CTE compatibility
with PCB. Consequently, AM-based hybrid manufacturing is capable of fabricating protective/functional bodies
for electronics.",,,,,,
"['Raval, Jay K.', 'Kazi, Aamer A.', 'Guo, Xiangyu', 'Zvanut, Ryan', 'Lee, Chabum', 'Tai, Bruce L.']",2021-12-06T23:24:51Z,2021-12-06T23:24:51Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90715', 'http://dx.doi.org/10.26153/tsw/17634']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['AM machinery', 'tool failure', 'surface finish', 'Ti-6Al-4V', 'additive manufacturing']",Preliminary Study on Machining of Additively Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/32fc39b7-7610-4be4-8d11-17f886432998/download,University of Texas at Austin,"Additively manufactured metals differ from their conventionally produced counterparts due to
the inherent material inhomogeneity, porosity, and thermal stress induced by the process. These
differences make the machining of additively manufactured metals more difficult and cause
premature tool failure or unexpected surface finish at certain conditions. This study takes the first
step to investigate and identify the causes of these issues, particularly for Ti-6Al-4V. Printed and
wrought samples, as well as heat treatment effect, are compared in a dry cutting condition at a
cutting speed of 90 m/min in terms of cutting power, vibration, temperature, and produced
surface finish. The results show a lower cutting power and more vibration for as-printed Ti
samples, indicating a less ductile microstructure and inclusion of pores. Heat treatment can
eliminate these phenomena. There is no significant difference found in the produced surface
finish at the current cutting condition.",,,,,,
"['Yildirim, E.', 'Yin, X.', 'Guceri, S.', 'Sun, W.']",2020-02-27T19:50:50Z,2020-02-27T19:50:50Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80098', 'http://dx.doi.org/10.26153/tsw/7119']",eng,2006 International Solid Freeform Fabrication Symposium,Open,single-walled carbon nanotubes,A Preliminary Study on Using Multi-Nozzle Polymer Deposition System to Fabricate Composite Alginate/Carbon Nanotube Tissue Scaffolds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5693b5d8-64b5-4102-bfa8-73de52e96705/download,,"Three-dimensional composite alginate/single wall carbon nanotube (SWCNT) scaffolds
encapsulated with endothelial cells were fabricated by a multi-nozzle biopolymer freeform
deposition system. This system enables the converting of CAD designed scaffold pattern into
process toolpaths and the use of computer control program to guide the nozzle deposition at
spatial position for layered fabrication of 3D tissue scaffolds. The morphological, mechanical,
structural and biological properties of as-fabricated scaffolds were characterized by optical
microscope, SEM, Microtensile testing machine, Alamar Blue Assay, and Live-Dead Assay,
respectively. The multi-nozzle deposition system demonstrated a highly efficient and effective
process to build tissue scaffold or cell embedded constructs. Characterization results showed that
the incorporation of SWCNT into alginate not only enhanced the mechanical strength of the
scaffolds but also improved the cell affinity and the interaction with substrate. Further cell
culture experimental results also showed that the incorporation of SWCNT in alginate enhanced
endothelial cell proliferation compared with pure alginate scaffold.",,,,,,
"['Bailey, Alta C.', 'Merriman, Abbey', 'Elliott, Amelia', 'Basti, Mufeed M,']",2021-10-28T14:51:17Z,2021-10-28T14:51:17Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89656,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['part density', 'binder effect', 'nanoparticle effect', 'binder jetting']",Preliminary Testing of Nanoparticle Effectiveness in Binder Jetting Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e44a23fd-c1a3-4588-ad62-36e463205bc0/download,University of Texas at Austin,"Binder jetting works by selectively depositing a binder with an inkjet print head into
layers of powdered material. Compared with other metal Additive Manufacturing (AM)
processes, binder jetting has significant potential for near-term adoption in manufacturing
environments due to its reliability and throughput. The Achilles heel of binder jetting, however,
is the inability to produce fully dense, single-alloy materials. The lack of density in printed
binder jet parts is strictly dictated by the packing factor of the powder feedstock. Adding
nanoparticles during printing will not only increase the part’s packing factor but may also serve
as a sintering aid. This study focuses on the effect of both the binder and nanoparticles on the
final part density. As an unintended consequence of high nanoparticle loading, printed parts
underwent a significant increase in porosity during the curing process. This unintended
consequence is the apparent result of the nanoparticles blocking the exit of the solvent vapor
during the curing step. Additionally, nanoparticle use for densification is validated with SEM
imagery.",,,,,,
"['Crocker, James E.', 'Sun, Lianchao', 'Shaw, Leon L.', 'Marcus, Harris L.']",2019-02-26T20:15:31Z,2019-02-26T20:15:31Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73494', 'http://dx.doi.org/10.26153/tsw/644']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SALDVI', 'macro-component']",Preparation and Properties of In-Situ Devices Using the SALD and SALDVI Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7085d303-1e63-4204-b56d-0d67f00eed5e/download,,"One of the many advantages of Selective Area Laser Deposition (SALD) and Selective
Area Laser Deposition Vapor Infiltration (SALDVI) is that they can be used to embed in-situ
micro-sensors within macro-components. A single-point SiC/C thermocouple sensor embedded
within a SiC macro-component and electrically insulated with silicon nitride layers has been
demonstrated. In many applications, multi-point sensors within a single component are needed,
e.g., in monitoring the temperature gradient and distribution at different positions. In this paper,
multi-point thermocouple devices are demonstrated. The macro-component is a SiC bulk shape
made by infiltrating vapor deposited silicon carbide into a silicon carbide powder bed using the
SALDVI technique. Multiple SiC/C thermocouples are embedded in-situ in the SiC bulk shape
using the SALD technique. The transient and steady state responses ofthe embedded
thermocouples are compared to reference thermocouples probing the surfaces of the bulk shape.",,,,,,
"['Regenfuss, P.', 'Streek, A.', 'Hartwig, L.', 'Klötzer, S.', 'Brabant, Th.', 'Horn, M.', 'Ebert, R.', 'Exner, H.']",2020-03-05T20:15:51Z,2020-03-05T20:15:51Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80156', 'http://dx.doi.org/10.26153/tsw/7177']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Micro Sintering,Principles of Laser Micro Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b52774c0-49c3-4e7f-807f-5ef422c2e6d1/download,,"Laser Micro Sintering was introduced to the international community of freeform fabrication
engineers in 2003 and has since been employed for a variety of applications. It owes its unique
features to certain effects of q-switched pulses that formerly had been considered detrimental in
selective laser sintering. Besides sub-micrometer sized powders also materials with grain sizes
of 1-10 micrometers can be sintered. Surface and morphology of the product are influenced by
grain size and process environment. First results have been achieved with processing ceramic
materials.
A comprehensive overview of the process and the features is given supported by
experimental evidence. Routes of further development are indicated.",,,,,,
"['Hoopes, Zachary A.', 'Karschner, Michael L.', 'Kelly, Jocelynn', 'Miney, William B.', 'Ounaies, Zoubeida', 'Basak, Amrita']",2021-12-06T21:18:45Z,2021-12-06T21:18:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90674', 'http://dx.doi.org/10.26153/tsw/17593']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['direct ink writing', 'DIW', 'biopolymer', 'ethyl cellulose', 'printability']",Printability Assessment of Cellulose-Based Polymer Structures using Direct Ink Writing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9e1135df-5709-4c33-b36d-5f45857e0ae8/download,University of Texas at Austin,"In this paper, we demonstrate the preparation and printing of ethyl cellulose, a cellulose derivative,
using a custom-modified direct ink writing (DIW) printer. Ethyl cellulose (EC) is widely used as
a thin-film coating in controlled-release vitamins and medical pills as well as a thickener in the
food, cosmetics, and other industries. It is, therefore, an attractive bio-mass derived polymer for
3D printing. Two types of ethyl cellulose, with different molecular weights (Mw), are dissolved in
alpha-terpinol solvent to assess the feasibility of printing the polymer. In total, eleven different
slurries are prepared at different solid weight percent. The stir time, stir temperature, and resting
time are then varied. The results show that 10 wt. % ethyl cellulose slurry performs best for the
initial printability assessment. Following printing, this slurry holds its shape, and shows uniform
thickness in rectangular and snake patterns.",,,,,,
"['Jones, J.B.', 'Wimpenny, D.I.', 'Chudasama, R.', 'Gibbons, G.J.']",2021-10-05T14:45:35Z,2021-10-05T14:45:35Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88384', 'http://dx.doi.org/10.26153/tsw/15323']",ita,2011 International Solid Freeform Fabrication Symposium,Open,"['laser printing', 'selective deposition', 'fiber laser consolidation', 'selective processing', 'printed circuit boards']",Printed Circuit Boards By Selective Deposition and Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/705d5fc4-8119-44a7-a0b5-fd057eee0149/download,University of Texas at Austin,"With electronic applications on the horizon for AM, comes the dilemma of how to consolidate
conductors, semi-conductors, and insulators in close proximity. To answer this challenge, laser
printing (selective deposition) was used in tandem with fiber laser consolidation (selective
processing) to produce PCBs for the first time. This combination offers the potential to generate
tracks with high mechanical integrity and excellent electrical conductivity (close to bulk metal)
without prolonged exposure of the substrate to elevated temperatures. Herein are the findings of
a two-year feasibility study for a “one-stop” solution for producing PCBs (including conductive
tracks, dielectric layers, protective resists, and legends).",,,,,,
"['Foster, Diana', 'Corey, Chris', 'Fisher, Chris', 'Smith, Caitlin', 'Paolella, Arthur']",2021-11-30T20:54:18Z,2021-11-30T20:54:18Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90544', 'http://dx.doi.org/10.26153/tsw/17463']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['quasi-optical', 'millimeter', 'wave guide', 'lens systems', 'radio frequency', 'CLIP', 'PolyJet', 'SLS', 'radar', 'space', 'communications']",Printed Materials and Their Effects on Quasi-Optical Millimeter Wave Guide Lens Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5339d167-2e7e-4835-96c3-ebd21edb3417/download,University of Texas at Austin,"This study of 3D printed quasi-optical (Q-O) millimeter wave guide lens systems is
presented in three phases: the characterization of 3D printed materials for radio frequency (RF)
applications and systems; the development and demonstration of 3D printing technology for RF
systems; and the design process, simulation, fabrication, and testing of RF lens systems. The first
phase explores the ability to print high-quality materials with fine resolution and the determination
of each material’s dielectric constant and loss tangent. The second phase details the development
of dual biconvex shaped lens systems and the resulting test data. The third phase combines the
former stages’ results to model, print, and test a set of lenses pre-aligned with an integrated support
structure. These lens systems were tested up to 100 GHz with demonstrated focusing gain of 22.1
dB.",,,,,,
"['Periard, Daniel', 'Malone, Evan', 'Lipson, Hod']",2020-03-10T16:02:16Z,2020-03-10T16:02:16Z,9/5/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80218', 'http://dx.doi.org/10.26153/tsw/7237']",eng,2007 International Solid Freeform Fabrication Symposium,Open,freeform fabrication,Printing Embedded Circuits,Conference paper,https://repositories.lib.utexas.edu//bitstreams/73f38f5c-1fd6-4ee4-8332-2c447d223337/download,,"Automated manufacturing technologies such as freeform fabrication can greatly
reduce the cost and complexity of infrastructure required to manufacture unique devices
or invent new technologies. Multi-material freeform fabrication processes under
development have the potential to automatically build complete functional devices
including electronics. Making this technology available to creative individuals will
revolutionize art and invention, but requires extensive simplification and cost reduction
of what is still a laboratory technology. The combination of a Fab@Home Model 1
personal fabrication system and commercially available materials allows the
demonstration of simple and inexpensive freeform fabrication of functional embedded
electrical circuits, and useful devices. Using this approach, we have been able to
demonstrate an LED flashlight, functional printed circuit boards in 2-dimensions and 3-
dimensions that are actually entirely printed, and a child’s toy with embedded circuitry.
These results, and the materials and methods involved in producing them will be
presented in detail.",,,,,,
"['Periard, Dan', 'Schaal, Noy', 'Schaal, Maor', 'Malone, Evan', 'Lipson, Hod']",2020-03-10T16:20:10Z,2020-03-10T16:20:10Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80223', 'http://dx.doi.org/10.26153/tsw/7242']",eng,2007 International Solid Freeform Fabrication Symposium,Open,freeform fabrication,Printing Food,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8502579-6a20-43a5-a4f6-9272b600bd45/download,,"This paper examines the possible applications of food as a raw
material in freeform fabrication, and provides several demonstrations of
edible three-dimensional objects. The use of edible materials offers several
advantages: First, it opens the door to the application of SFF technology in
custom food industry, such as manufacturing of complex confections with
specialized geometries and intricate material compositions. For
pedagogical purposes, edible materials provide an easily accessible, nontoxic and low cost way to experiment with rapid prototyping techniques
using educational systems such as Fab@Home. For more traditional SFF
technologies, food materials with appropriate rheological properties can
serve as sacrificial, bio-degradable, bio-compatible or recyclable materials
for structural support and draft-printing. We have used the Fab@Home
personal fabrication system to produce multi-material edible 3D objects
with cake frosting, chocolate, processed cheese, and peanut butter. These
are just indicative of the range of potential edible materials and
applications.",,,,,,
"['Rosen, David W.', 'Margolin, Lauren', 'Vohra, Sanjay']",2020-03-11T15:19:56Z,2020-03-11T15:19:56Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80249', 'http://dx.doi.org/10.26153/tsw/7268']",eng,2008 International Solid Freeform Fabrication Symposium,Open,ultrasonic actuation,Printing High Viscosity Fluids using Ultrasonic Droplet Generation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/25f51b61-7710-4f3a-89fa-de5a9a549d94/download,,"A new printing technology based on ultrasonic actuation (~1 MHz) is presented that has the
potential to print high viscosity fluids. In this paper, we describe the print-head’s operating
principles and construction. Acoustic focusing in the nozzles produces high pressure gradients
that help eject the fluid which, under the proper conditions, forms droplets. Two types of models
are presented to attempt to predict print-head behavior over a range of conditions. The first
model borrows from simple fully developed, laminar flows to estimate printing conditions based
on fluid properties, as well as printing pressures. The second model captures the dynamic
behavior of the print-head to estimate cavity resonances that lead to acoustic focusing and
potentially droplet generation. We report on experiments with several types of fluids that
demonstrate the technology’s potential.",,,,,,
"[""O'Donnell, M."", 'Budan, J.', 'McGuire, J.', 'Jalagam, P.', 'Kulkarni, Achyuth', 'Ansell, T.Y.']",2024-03-25T22:39:12Z,2024-03-25T22:39:12Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124326', 'https://doi.org/10.26153/tsw/50934']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['hydrophobic surfaces', 'stainless steel', 'graphene', 'additive manufacturing']",PRINTING HYDROPHOBIC STAINLESS STEEL GRAPHENE COMPOSITES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/02a70354-1db8-4c06-a1c9-8a086235ed79/download,University of Texas at Austin,"Hydrophobic surfaces have low surface energies, which prevents water droplets from
wetting the surface. Metals typically have high surface energies leading to highly wettable,
hydrophilic behavior. Nano-structuring metallic surfaces could be a way of making a metallic
surface hydrophobic potentially leading to improved corrosion resistance, drag reduction, etc. 3Dprinting a metal matrix nanocomposite maybe a scalable method to fabricate hydrophobic metals.
Graphene nanoplatelets (GNP) were mixed with 316L stainless-steel (SS) powder and printed on
a selective laser melting platform. The composite samples included 0, 1, 2, and 3 vol% GNP. Initial
printing jobs ran into some issues that were addressed by adding a vibration source and aluminum
foil to the inside of the powder hopper. Additionally, energy density was set higher than 60 J/mm3
to avoid lack of fusion issues. Printing of small and large plates of composite samples was
performed at energy densities starting from 60 J/mm3 going up to 100 J/mm3
. As-printed composite
sample surfaces consistently exhibited hydrophobic behavior with contact angles exceeding 90°.
After polishing, the surfaces exhibited hydrophilic behavior. What is compelling; however, is that
while contact angles for pure SS was as expected, i.e., angles < 80°, the composite samples showed
angles between 80° and 90°, drawing closer to 90° with an increase in GNP.",,,,,,
"['Granizo, Juan', 'Gribbins, Cassandra', 'Steinhauer, Heidi']",2021-11-08T23:35:23Z,2021-11-08T23:35:23Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90078', 'http://dx.doi.org/10.26153/tsw/16999']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['printing orientation', 'implicit', 'additive manufacturing', 'middle school students', 'high school students']",Printing Orientation and How Implicit It Is,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc8c844c-8ba2-4ec6-ae67-4dfe538764ea/download,University of Texas at Austin,"A study on how implicit the printing orientation is for people with no previous experience
in additive manufacturing was conducted. The study was developed with middle and high school
students divided into two groups, where only one group was introduced a series of activities to
show the importance of printing orientation and its relation with stress and strength of parts. Both
of the groups were evaluated in the construction of a wing-box using 3-D printing pens. The study
also took into consideration the amount of filament that was used in the assembly of the structure,
to keep track of the most optimized models. The wing-box were then tested until failure to study
its structural integrity. Finally, a detailed comparison between the two studied groups was perform
to show how implicit the printing orientation is in the design process of parts.",,,,,,
"['Norris, Marshall', 'Fidan, Ismail']",2024-03-26T21:39:10Z,2024-03-26T21:39:10Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124423', 'https://doi.org/10.26153/tsw/51031']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'metallic paste', '17-4PH', 'parameter optimization', 'response surface']",PRINTING PARAMETER OPTIMIZATION OF EXTRUDED METAL PASTE BY RESPONSE SURFACE TECHNIQUE,Conference paper,https://repositories.lib.utexas.edu//bitstreams/306d6744-b5d5-41c4-b698-c17367e6ec92/download,University of Texas at Austin,"This research is focused on optimizing printing parameters using the response surface (RS)
methodology. When printing parameters are not optimized, the resulting prints contain an
unacceptable surface finish, porosity, or the print fails entirely as the lower portion of the print will
not be able to withstand the weight of consecutive layers. Printing parameters, layer height, and
percent infill were adjusted for the study while material flow rate and print head speed were held
constant. RS is a statistical based eigenvalue process that uses data points on a three-dimensional
curve to predict and identify local maxima or minima. For this study, RS was used to identify the
inflection point where surface finish is optimized. A starting point for the parameters begins with
rheological characterization of the paste and geometric modeling (or brute force approach). Once
the parameters are able to produce an acceptable surface finish, the RS approach was used to refine
printing parameters.",,,,,,
"['Zhang, Jingwei', 'Liou, Frank', 'Seufzer, William', 'Newkirk, Joseph', 'Fan, Zhiqiang', 'Liu, Heng', 'Sparks, Todd E.']",2021-10-11T22:26:10Z,2021-10-11T22:26:10Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88668', 'http://dx.doi.org/10.26153/tsw/15602']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['microstructure evolution', 'metal solidification', 'laser based additive manufacturing', 'Cellular Automaton - Finite Element', 'metal deposition']",Probabilistic Simulation of Solidification Microstructure Evolution During Laser-Based Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9f27299-6b7e-447f-af4c-c943da56c078/download,University of Texas at Austin,"A predictive model, based on a Cellular Automaton (CA) - Finite Element (FE) method,
has been developed to simulate microstructure evolution during metal solidification for a laser
based additive manufacturing process. The macroscopic FE calculation was designed to update
the temperature field and simulate a high cooling rate. In the microscopic CA model, heterogeneous nucleation sites, preferential growth orientation and dendritic grain growth kinetics
were simulated. The CA model was able to show the entrapment of neighboring cells and the
relationship between undercooling and the grain growth rate. The model predicted the dendritic grain size, structure, and morphological evolution during the solidification phase of the
deposition process. Model parameters for the simulations were based on stainless steel 316 (SS
316).",,,,,,
"['Lak, Sui Man', 'Li, Chi Chung', 'Toombs, Joseph', 'de Beer, Martin', 'Taylor, Hayden']",2024-03-26T21:42:53Z,2024-03-26T21:42:53Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124424', 'https://doi.org/10.26153/tsw/51032']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['tomographic fuorescence imaging', 'temperature', 'degree-of-conversion', 'additive manufacturing']",Probing Temperature and Degree-of-conversion States via Tomographic Fluorescence Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b9a0def-165e-4b2d-be6e-5356bf178411/download,University of Texas at Austin,"Tomographic volumetric additive manufacturing rapidly solidifies freeform objects via
photopolymerization, which raises both local temperature and degree-of-conversion (DOC). Insitu monitoring of temperature and DOC during the printing process is crucial for metrology and
process control. In this study, we propose a tomographic fluorescence imaging technique to
detect the spatiotemporal evolution of temperature and DOC during volumetric printing. Our
solution employs a fluorescent dye that is sensitive to both variations in temperature and DOC.
DOC is considered as a function of, and is expressed in, the absorbed optical dose of the resin.
By tomographically measuring changes in the dye’s fluorescence intensity and feeding such
changes to a temperature–dose–intensity calibration, the local dose and temperature during the
print can be confined to a set of possible states. At exemplar locations where a priori information
is known for one quantity, the other quantity can be resolved. This work illustrates the potential
of and lays foundations for the development of two-wavelength spatiotemporal measurement
systems that uniquely resolve both temperature and DOC.",,,,,,
"['De Coninck, H.', 'Dejans, A.', 'Meyers, S.', 'Buls, S.', 'Kinds, Y.', 'Soete, J.', 'Van Puyvelde, P.', 'Van Hooreweder, B.']",2024-03-25T22:51:58Z,2024-03-25T22:51:58Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124328', 'https://doi.org/10.26153/tsw/50936']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['Polyamide 12', 'glass fibres', 'fibre/matrix behaviour', 'glass fibre sizing', 'laser sintering', 'deposition system', 'additive manufacturing']",PROCESS AND MATERIAL OPTIMISATIONS FOR INTEGRATION OF CHOPPED GLASS FIBRES IN LASER SINTERED POLYMER PARTS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2e85d4d9-2634-4f37-8779-a9b2db3286e4/download,University of Texas at Austin,"Additively manufactured polymer composites gain popularity in a variety of industries such as aerospace,
biomedical and automotive. Laser sintering (LS) is a well-known AM process that typically uses polyamide which
can serve as matrix material. Hence LS has the potential to produce reinforced polymers that can meet demanding
requirements. In previous research, issues with powder flowability and poor fibre dispersion led to limited
increase of mechanical properties. To overcome this, a novel fibre deposition system was recently developed and
optimised at KU Leuven to successfully produce fibre reinforced LS samples with random inter- and intralayer
fibre orientations. A limited but promising influence of deposited glass fibres on produced LS parts was noted
after mechanical testing. In this work, the influence of different (heat) treatments on glass fibres used during LS
will be discussed as well as the resulting differences in the fibre/matrix behaviour as analysed through hot stage
microscopy.",,,,,,
"['Artreya, S.', 'Kalaitzidou, K.', 'Das, S.']",2021-09-29T14:57:24Z,2021-09-29T14:57:24Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88189', 'http://dx.doi.org/10.26153/tsw/15130']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['electrically conductive polymer composites', 'Selective Laser Sintering', 'Nylon-12', 'electrical conductivity']",Process and Properties of Carbon Black-Filled Electrically Conductive Nylon-12 Nanocomposites Produced by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ff634746-d7fe-49eb-88ca-a986c63a1da0/download,University of Texas at Austin,"Electrically conductive polymer composites are suitable for use in the manufacture of
antistatic products and components for electronic interconnects fuel cells and electromagnetic
shielding. Selective laser sintering (SLS) was used to investigate the fabrication of
electrically conductive nanocomposites of Nylon-12 filled with 4% by weight of carbon
black. The effect of laser power and the scan speed on the flexural modulus and part density
of the nanocomposite were studied. The set of parameters that yielded the maximum flexural
modulus and part density was used to fabricate specimens to study the tensile, impact,
rheological and viscoelastic properties. The electrical conductivity of the nanocomposite was
investigated. The densities and the microstructures of the nanocomposites were studied using
optical microscopy and scanning electron microscopy (SEM). The morphology of the
nanocomposites was investigated using X-Ray diffraction (XRD) and differential scanning
calorimetry.",,,,,,
"['Branner, G.', 'Strasser, G.', 'Zaeh, M.F.']",2020-03-09T14:50:59Z,2020-03-09T14:50:59Z,9/5/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80189', 'http://dx.doi.org/10.26153/tsw/7208']",eng,2007 International Solid Freeform Fabrication Symposium,Open,indirect metal laser sintering,Process Chain for Numerical Simulation of IMLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/411bab75-ccde-4443-b6a1-c30772755415/download,,"Additive layer manufacturing methods imply, among other advantages, extensive flexibility
concerning their ability to realize mass customization. Despite various efforts towards process
enhancement, numerous deficiencies concerning part distortion or residual stresses are still
observable. The present work deals with the definition of an efficient process chain for
numerical simulation of indirect metal laser sintering (IMLS), in order to improve
dimensional accuracy. The underlying method is based on investigations of dilatometric behavior of iron based powder, which is integrated into reaction kinetic models and coupled
with a finite element analysis (FEA). Thus, singular process steps, e. g. solid phase sintering,
phase transformations or infiltration, are numerically modelled with adequate accuracy.
Referring to thermomechanical simulation, possibilities for pre-scaling of part geometries are
presented.",,,,,,
"['Kovacevic, R.', 'Beardsley, H.']",2019-02-19T16:51:33Z,2019-02-19T16:51:33Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73429', 'http://dx.doi.org/10.26153/tsw/581']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'stereolithography']",Process Control of 3D Welding as a Droplet-Based Rapid Prototyping Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f9ed1f6e-a110-4a69-8e02-122c9f652a41/download,,"Three-dimensional welding is investigated as a rapid prototyping technique for the production
of real Inetallic parts using gas metal arc welding principles. A high speed machine vision
system is used to study the correlation between droplet transfer parameters and resultant weld
penetration characteristics. Experimental work is conducted to determine how droplet transfer
frequency, droplet size, and number of passes affect the geometrical and Inetallurgical properties
ofthe weld penetration. A finite element analysis is performed in order to study what influence
additional layering has on the cooling characteristics and resultant penetration profile.",,,,,,
"Landers, Robert G.",2019-11-20T16:32:28Z,2019-11-20T16:32:28Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78475', 'http://dx.doi.org/10.26153/tsw/5560']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Laser Metal,Process Control of Laser Metal Deposition Manufacturing - A Simulation Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7b6fadc-4c5f-4af7-a5d0-a0190986a26b/download,,"The laser metal deposition process is a rapid manufacturing operation capable of producing
functional prototypes with complex geometries and thin sections. This process inherently
contains significant uncertainties and, therefore, extensive experimentation must be performed to
determine suitable process parameters. An alternative is to directly control the process on–line
using feedback control methodologies. In this paper, a nonlinear control strategy based on
feedback linearization is created to automatically regulate the bead morphology and melt pool
temperature. Extensive simulation studies are conducted to validate the control strategy.","The author gratefully acknowledges the financial support of the National Science Foundation
(DMI–9871185), Society of Manufacturing Engineers (#02022–A), Missouri Research Board,
and UMR’s Intelligent Systems Center.",,,,,
"['Das, Suman', 'Crawford, Richard H.', 'Beaman, J.J.']",2018-04-18T17:35:58Z,2018-04-18T17:35:58Z,1992,Mechanical Engineering,doi:10.15781/T2SF2MV5H,http://hdl.handle.net/2152/64364,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'High Temperature Workstation', 'HTW']",Process Control System for a High Temperature Workstation performing the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1b464dec-275e-4400-8c92-da06e0b64f4f/download,,"Thispaper describes the design and implementation ofa Computer Process Control System for a High Temperature Workstation performing Selective Laser Sintering of metal and .ceramic powders. As compared to our previous machine [1], the increased complexity and sophistication .of·the.new workstation [21 requires a variety of measurement and control devices which are.interfaced to a process controlcomputer. Among these are a. gas analyzer, a data logger, a step motor controllerandaCNC controller. This process control system incorporates a XView ( aX Window System Toolkit) based Graphical User Interface which allows the user.to set and change process parameters on-line as well as receive graphical feedback onthe process.",,,,,,
"Tille, Carsten",2020-02-13T19:51:58Z,2020-02-13T19:51:58Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79970', 'http://dx.doi.org/10.26153/tsw/6995']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Stereolithography,Process Errors and Aspects for Higher Resolution in Conventional Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dcc10f81-2bed-40bb-a78f-070ea4a5030f/download,,"Due to the rapid development of precision manufacturing technologies, there is a growing
market need for appropriate rapid prototyping methods with higher resolution. This paper
presents aspects for a general optimization of stereolithography accuracy and gives a deeper
analysis of important process errors.
Beside a higher precision due to improved optical components, it can be shown that for a better
vertical resolution one must mainly reduce the penetration depth of the photopolymer. We found
that this is also possible with conventional stereolithography materials by using a different
wavelength, achieving cured rugged layers with a thickness of 20 micrometer.
The major accuracy aspect lies in the understanding of the layer deposition process. A CFD
(computational fluid dynamics) study helps to describe important phenomena of blade based
coating techniques. As a result, the inaccuracy of the layer deposition is the general limiting
factor in stereolithography.
This knowledge can be directly applied to commercial stereolithography systems helping users to
achieve higher process accuracy.",,,,,,
"Chi, Chen",2018-11-16T14:57:33Z,2018-11-16T14:57:33Z,1996,Mechanical Engineering,doi:10.15781/T2KP7VB2P,http://hdl.handle.net/2152/70284,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'rapid prototyping', '3-dimensional objects']",Process Insight About LOM Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1567cc04-f0ca-4b9c-a8d5-7ae979d154a6/download,,"A Laminated Object Manufacturing (LOM) machine offers much freedom in terms ofsystem
parameters: laser cutting speed, laser power setting, roller speed, roller temperature, and so on.
Because ofthis freedom, users can choose any number, within certain limitations, to create wellconstructed
objects. Obviously, each user has a different definition for the quality of an object.
Therefore this freedom has induced some confusion. Most commonly, each customer has his own
preferred parameter data sets. These sets may not be the same but they are good sets. We need to
devise a method as a guideline for system parameters to ensure a consistency in the construction
of objects.
We have been studying actual laser power at different cutting speeds, actual cutting curves
and bonding curves for different materials, actual temperature distribution, etc. These results
have helped us find a proper way to set system parameters so that any user can run LOM
machines without difficulty and confusion. The research methodology and results are elaborated
in this paper.",,,,,,
"['Lehmann, Maja', 'Zaeh, Michael F.']",2021-11-16T15:57:27Z,2021-11-16T15:57:27Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90323', 'http://dx.doi.org/10.26153/tsw/17244']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['cobalt gradient', 'WC-Co', 'sintering', 'binder jetting', 'nanoparticles']",Process Integrated Production of WC-Co Tools with Local Cobalt Gradient Fabricated by Binder Jetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/decc78aa-9a02-4f5f-9178-ed9a8965e7ce/download,University of Texas at Austin,"Producing complex shaped tungsten carbide cobalt (WC-Co) tools by classical technologies
is difficult and often impossible due to their high hardness and brittle fracture behavior. Additive
Manufacturing (AM) is a suitable technology for creating complex structures and simultaneously
shortening expensive machining processes. Binder Jetting (BJ) is an innovative AM technology
that offers several advantages over laser-based processes, for example low manufacturing costs and
high build-up rates. Binders with nanoparticle additives have already proven to be effective in increasing the packing density of the powder bed and improving the sintering properties. Additionally, they offer the possibility of selectively changing the material composition in the part. This
paper presents a concept for the use of nanoparticles to generate gradients in the green compact,
which leads to a cobalt gradient in the part after sintering. The possibility of introducing particles
locally into complex structures allows local modification of the material properties.",,,,,,
"['Cooke, A.L.', 'Moylan, S.P.']",2021-10-04T20:30:55Z,2021-10-04T20:30:55Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88340', 'http://dx.doi.org/10.26153/tsw/15279']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['process intermittent measurements', 'additive manufacturing', 'three-dimensional printing']",Process Intermittent Measurement for Powder-Bed Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3bc4c474-d37a-4c0a-9036-37651f7f6f26/download,University of Texas at Austin,"Process intermittent measurements of parts fabricated by additive manufacturing (AM)
can enable both process improvement and characterization of internal part geometries. The
planar, layer-upon-layer nature of most AM processes allows two-dimensional geometric
measurements with a vision system, because the part’s current layer is continually in focus. Proof
of this concept has been shown through measurement of parts made using a three-dimensional
(3D) printer. Process intermittent measurements were compared to contact and non-contact
measurements of the finished parts to characterize deviations in printed layer positions and
changes in part dimensions resulting from post-process treatments.",,,,,,
"['Beuth, Jack', 'Fox, Jason', 'Gockel, Joy', 'Montgomery, Colt', 'Yang, Rui', 'Qiao, Haipeng', 'Soylemez, Emrecan', 'Reeseewatt, Pete', 'Anvari, Amin', 'Narra, Sneha', 'Klingbeil, Nathan']",2021-10-11T21:54:40Z,2021-10-11T21:54:40Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88656', 'http://dx.doi.org/10.26153/tsw/15590']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'process mapping', 'direct metal deposition', 'melt pool geometry', 'microstructure']",Process Mapping for Qualification Across Multiple Direct Metal Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5b02008-133b-4e40-893d-96f1d557e8c6/download,University of Texas at Austin,"This paper gives an overview of work by the authors developing process mapping
methods for additive manufacturing (AM), capturing the dependence of melt pool geometry and
microstructure on primary processing variables under steady-state and transient conditions. This
work is being applied to the task of process qualification and is being applied across multiple
AM processes including electron beam wire feed, electron beam powder bed, laser powder bed,
and laser powder stream processes. Process mapping methods are now allowing all of these
processes acting in very different regions of processing space to be characterized and analyzed in
a unified way. A few insights from this approach are summarized.",,,,,,
"['Montgomery, Colt', 'Beuth, Jack', 'Sheridan, Luke', 'Klingbeil, Nathan']",2021-10-21T17:57:06Z,2021-10-21T17:57:06Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89411,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed additive manufacturing', 'nickel superalloys', 'Inconel 625', 'process mapping']",Process Mapping of Inconel 625 in Laser Powder Bed Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4262fbd-f005-4f4d-800e-b3cc5bab848f/download,University of Texas at Austin,"Understanding laser powder bed additive manufacturing of nickel superalloys is important for
the widespread adoption of the technology. To promote adoption, melt pool geometry as well as
microstructure prediction and control must be thoroughly understood. In this research Inconel
625 is investigated to determine optimal regions of processing space within the laser powder bed
operating range. Single bead and pad geometries are investigated along with solidification
microstructure and defects by utilizing a process mapping approach. The effect of powder
addition on the process is also examined. Results from models are compared with experimental
results to verify modeling techniques. Insights are gathered by comparing these results to those
of other alloy systems in the laser powder bed operating space.",,,,,,
"['Fox, Jason', 'Beuth, Jack']",2021-10-11T22:00:47Z,2021-10-11T22:00:47Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88658', 'http://dx.doi.org/10.26153/tsw/15592']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['wire feed electron beam additive manufacturing', 'additive manufacturing', 'process mapping', 'Ti-6Al-4V', '3D finite element simulation', 'aerospace']",Process Mapping of Transient Melt Pool Response in Wire Feed E-Beam Additive Manufacturing of Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2cb071b2-260f-409d-92c4-83a324cd55f2/download,University of Texas at Austin,"Wire feed electron beam additive manufacturing processes are candidates for
manufacturing and repair in the aerospace industry. In order to implement feedback or
feedforward control approaches, the time needed for a change in process variables to translate
into changes in melt pool dimensions is a critical concern. In this research, results from 3D finite
element simulations of deposition of Ti-6Al-4V are presented quantifying the transient response
of melt pool dimensions to rapid changes in beam power and travel velocity. Results are plotted
in beam power vs. beam velocity space, following work by the authors developing P-V Process
Maps for steady-state melt pool geometry. Transient responses are determined over a wide range
of process variables. Simulation results are compared to initial results from experiments
performed at NASA Langley Research Center.",,,,,,
"['Vasinonta, Aditad', 'Beuth, Jack', 'Griffith, Michelle']",2019-09-23T15:37:40Z,2019-09-23T15:37:40Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75939', 'http://dx.doi.org/10.26153/tsw/3038']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Residual,Process Maps for Controlling Residual Stress and Melt Pool Size in Laser-Based SFF Processes  200,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aefec396-2f89-499f-b0ab-1b0dcb30124f/download,,"Thermal control of solid freeform fabrication processes is critical for obtaining consistent build conditions and in limiting residual stress-induced tolerance losses. In this paper, thermomechanical models are presented for the building of thin-walled structures by laser-based SFF processes. The simulations are used to develop two non-dimensional plots (termed process maps) that quantify the effects of changes in wall height, laser power, deposition speed and part preheating on melt pool size (for consistent build conditions) and thermal gradients (for limiting residual stresses). Mechanical simulations are used to demonstrate the link between thermal gradients and maximum final residual stresses. Models are applied to the Laser Engineered Net Shaping (LENS) process; however, the general approach, insights and conclusions are applicable to most SFF processes involving a moving heat source. The two process maps described herein can be used together to determine optimal process variables for obtaining consistent melt pool length while limiting residual stress in the part. Results from the residual stress simulations also identify two important mechanisms for reducing residual stresses and quantify maximum stress reductions that can be achieved through manipulation of all process variables.",This research has been supported by the National Science Foundation under grant DMI9700320 and by Sandia National Laboratories under grant BE-0792.,,,,,
"['Vasinonta, Aditad', 'Beuth, Jack', 'Griffith, Michelle']",2019-03-17T13:35:45Z,2019-03-17T13:35:45Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73697', 'http://dx.doi.org/10.26153/tsw/839']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['LENS', 'SFF']",Process Maps for Laser Deposition of Thin-Walled Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5cec0fd7-2ad3-431a-9573-c406fb46342c/download,,"In solid freeform fabrication (SFF) processes involving thermal deposition, thermal control
of the process is critical for obtaining consistent deposition conditions and in limiting residual
stress-induced warping of parts. In this research, nondimensionalized plots (termed process maps)
are developedJrom numerical models of laser-based material deposition of thin-walled structures
that.map out the effects of changes in laser power, deposition speed and part preheating on process
parameters. The principal application of this work is to the Laser Engineered Net Shaping (LENS)
process under development at Sandia Laboratories; however, the approach taken is applicable to
any solid freeform fabrication process involving. a moving heat source. Similarly, although thinwalled structures treated in the current work, the same approach could be applied to other
commonly fabricated geometries. A process map for predicting and controlling melt pool size is
presented .and numerically determined results are compared against experimentally measured melt
poollengthsfor stainless steel deposition in the LENS process.",,,,,,
"['Wang, J.', 'Zhao, C.', 'Zhang, Y.', 'Jariwala, A.', 'Rosen, D.']",2021-11-04T14:56:55Z,2021-11-04T14:56:55Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89977,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['exposure controlled projection lithography', 'ECPL', 'photopolymerization', 'process modeling', 'in-situ monitoring', 'real-time']",Process Modeling and In-Situ Monitoring of Photopolymerization for Exposure Controlled Projection Lithography (ECPL),Conference paper,https://repositories.lib.utexas.edu//bitstreams/95c33e40-fd1f-45ad-9ed2-6fc600328633/download,University of Texas at Austin,"Exposure controlled projection lithography (ECPL) is an additive manufacturing process
in which photopolymer resin is used to fabricate three-dimensional features. During this process,
UV curing radiation, controlled by a dynamic mask, is projected through a transparent substrate
onto the resin. COMSOL software has been used to model the photopolymerization reaction
kinetics, predicting the cured part geometry based on certain process parameters. Additionally,
an Interferometric Curing Monitoring (ICM) system has been implemented to acquire real-time
information about the optical properties of the cured part. Potential sources of error with the real-time monitoring system were investigated. Additionally, refractive index and degree of
conversion changes were modeled throughout the reaction. Measured and simulated results were
compared to understand the ICM signal with the reaction kinetics. These comparisons were used
to validate the simulation model and identify system level errors that must be reconciled to
improve the accuracy and precision of the ECPL process.",,,,,,
"['Appana, S.', 'Ross, S.M.', 'Sims, C.', 'Schwerzel, R.', 'Jariwala, A.S.']",2024-03-26T21:47:10Z,2024-03-26T21:47:10Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124425', 'https://doi.org/10.26153/tsw/51033']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['fuild interface supported printing', 'stereolithography', 'resin', 'additive manufacturing']",PROCESS MODELING FOR FLUID-INTERFACE SUPPORTED RESIN PRINTING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb9a68d2-a9fd-4748-bd28-505427e9910f/download,University of Texas at Austin,"The article details the latest design and implementation of a stereolithography (SLA)
based technique, Fluid Interface Supported Printing (FISP). The FISP technique involves
printing from a thin resin layer above a static, immiscible support fluid. The support fluid
prevents deflection of overhanging geometry by providing a buoyant force equal to that of the
gravitational force due to the minute density difference between the support fluid and cured
resin. Complex curing and shrinkage dynamics are a primary knowledge gap. A COMSOL
multiphysics simulation model was developed to simulate the curing process, including
volumetric light intensity and optimized parameters for chemical reaction kinetics. The article
presents a pathway for further enhancing and validating the simulation model.",,,,,,
"['Griffis, J.C.', 'Shahed, K.S.', 'Okwudire, C.E.', 'Manogharan, G.P.']",2024-03-26T20:14:16Z,2024-03-26T20:14:16Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124390', 'https://doi.org/10.26153/tsw/50998']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'process modeling', 'additive manufacturing']",PROCESS MODELING OF MULTI-MATERIAL LASER POWDER BED FUSION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1a8b2f6a-b0cc-4385-8415-e7d99f1656f4/download,University of Texas at Austin,"Thermomechanical simulation of the laser powder bed fusion process has been a valuable tool to
help researchers and practitioners across the AM production cycle. For instance: Design for AM
(DfAM), material development, process mapping, prediction, and support generations, among
others. In this study, multi-material laser powder bed fusion (MM-LPBF), specifically of 904LSS
and CuSn10 are examined through process simulation and non-destructive techniques to determine
the impact of component orientation on defect mitigation. It is determined that material orientation
along the build direction is a large contributor in as-build defects. Introductory MM-LPBF
simulation is established to better understand the capabilities of current LPBF simulation tools in
accurately predicting and mitigating the new challenges of MM-LPBF simulation.",,,,,,
"['Munjuluri, N.', 'Agarwal, S.', 'Liou, F.W.']",2019-09-23T15:47:20Z,2019-09-23T15:47:20Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75943', 'http://dx.doi.org/10.26153/tsw/3042']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Modeling,"Process Modeling, Monitoring and Control of Laser Metal Forming 235",Conference paper,https://repositories.lib.utexas.edu//bitstreams/f633aec5-ea6b-43d3-b042-0b126494f346/download,,"Laser Metal Forming (LMF) process is one of the prominent Rapid Prototyping (RP) process that can be used to develop functional and fully dense metal parts. This paper addresses process modeling, monitoring and control of a laser metal forming system currently under development at Laser Aided Manufacturing Processes (LAMP) laboratory at University of Missouri–Rolla. This LMF system is based on a 2.5kW Nd:YAG laser as energy source and integrates five axis metal deposition and five axis machining. The current paper is aimed at characterization of effects of operating parameters such as traverse speed, mass flow-rate and laser power on the LMF process. A low cost monitoring system is being developed using off the shelf sensors like infrared temperature sensor, near infrared CCD camera and laser displacement sensor to measure the process index parameters. A closed loop control structure has been simulated for online control of the LMF process.","This research was supported by the National Science Foundation Grant Number DMI-9871185, Missouri Research Board, and a grant from the Missouri Department of Economic Development through the MRTC grant",,,,,
"['Wegner, A.', 'Witt, G.']",2021-10-04T22:14:17Z,2021-10-04T22:14:17Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88364', 'http://dx.doi.org/10.26153/tsw/15303']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'process monitoring', 'thermal imaging']",Process Monitoring in Laser Sintering Using Thermal Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6200bf44-1010-4093-bf7b-5a7249a82191/download,University of Texas at Austin,"In laser sintering, inhomogeneous shrinkage, warpage, in-build curling and poor repeatability of part properties are well-known problems. All these effects are significantly influenced by the inhomogeneous temperature distribution on the powder bed surface. For this reason, it is often asked for the integration of additional measuring equipment into the machines
for advanced process monitoring. In the research done, a thermal imaging system was successfully integrated into a laser sintering machine. Analyses were performed to understand the correlations between process parameters, the distribution of surface temperatures as well as the temperature of the melted material, and their influence on part properties.",,,,,,
"['Nassar, A.R.', 'Starr, Brandon', 'Reutzel, E.W.']",2021-10-19T19:13:34Z,2021-10-19T19:13:34Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89327,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['spectroscopy-based imaging', 'spectroscopy', 'directed energy deposition', 'Inconel-718', 'plume geometry']",Process Monitoring of Directed-Energy Deposition of Inconel-718 via Plume Imaging,Conference paper,https://repositories.lib.utexas.edu//bitstreams/be9b3423-8b66-408b-bdd9-9cae29c54578/download,University of Texas at Austin,"Laser-metal interactions typically results in vaporization and plume formation. These
phenomena are complex and depend upon the details of the laser-vapor-melt interactions. As such,
plume characteristics are sensitive to changes in process characteristics. Here, a spectroscopy-based imaging technique is presented for the monitoring of directed energy deposition of Inconel
718. Plume geometry is shown to be related to the processing parameters and geometry of single-bead deposits.",,,,,,
"['Leslie Budden, Christian', 'Lalwani, Aakil Raj', 'Meinert, Kenneth Ælkær', 'Daugaard, Anders Egede', 'Pedersen, David Bue']",2023-01-19T20:20:13Z,2023-01-19T20:20:13Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117252', 'http://dx.doi.org/10.26153/tsw/44133']",eng,2022 International Solid Freeform Fabrication Symposium,Open,PA11,Process optimisation of PA11 in fiber-laser powder-bed fusion through loading of an optical absorber,Conference paper,https://repositories.lib.utexas.edu//bitstreams/28001ace-6d24-4270-884c-9ae6cd97e992/download,,"Industrial laser processing is rapidly shifting towards fiber lasers with wavelengths between 780nm
and 2200nm. This can be largely contributed to the excellent beam properties and, ease of operation.
However, for Additive Manufacturing of polymers, CO2 lasers at wavelengths of 10,6µm are pre-
dominantly used. CO2 lasers provide unmatched energy absorption by the C-H bonds of Polyamide
(PA). To remedy this, the current study investigates using a high-power fiber laser (1080nm) for
consolidating PA11 mixed with a black optical absorber. Several compositions are produced by
mixing commercially available white and black powder. Aiming at finding the optimum optical
absorber loading and the corresponding process parameters, allowing the highest possible compo-
nent fidelity, while achieving the lightest hue of grey possible to allow for later colouring. The
experiment is conducted on an in-house developed Open Architecture Laser Powder-Bed Fusion
system. The parts are examined through, surface roughness, and mechanical characterisation.",,,,,,
"['Kempen, K.', 'Thijs, L.', 'Yasa, E.', 'Badrossamay, M.', 'Verheecke, W.', 'Kruth, J.-P.']",2021-10-05T13:47:43Z,2021-10-05T13:47:43Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88371', 'http://dx.doi.org/10.26153/tsw/15310']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['AlSi10Mg', 'Selective Laser Melting', 'process optimization', 'microstructural analysis', 'heat sinks']",Process Optimization and Microstructural Analysis for Selective Laser Melting of AlSi10Mg,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb26039f-60c4-4fe2-9b57-60499f0b387e/download,University of Texas at Austin,"AlSi10Mg is a typical casting alloy which is, due to its high strength/density ratio and thermal
properties, highly demanded in aerospace and automotive industries [1]. The alloy combination of aluminium,
silicon and magnesium results in a significant increase in strength and hardness which might even reach 300
MPa and 100 HBS, respectively, by applying a proper heat treatment [2]. Selective Laser Melting (SLM) of
AlSi10Mg, may be interesting to open new application areas such as heat sinks with complicated geometry [3],
and therefore is taken under investigation in this study. The process optimization of SLM for this alloy is not
straightforward due to high reflectivity and conductivity of the material. In this study, the main goal is to
optimize the process parameters, namely scan speed, scan spacing and laser power, to achieve almost full
density and good surface quality taking productivity as a key issue. A relative density up to 99% is achieved
with an average roughness (Ra) of about 20 µm measured on horizontal top surfaces while the scanning
productivity is about 4.4 mm3/s. The reasons spherical and irregular porosity formed are investigated.
Moreover, microstructural analysis of the SLM samples is conducted.",,,,,,
"['Keicher, D.M.', 'Lavin, J.M.', 'Appelhans, L.N.', 'Whetten, S.R.', 'Essien, M.', 'Mani, S.S.', 'Moore, P.B.', 'Cook, A.', 'Acree, N.A.', 'Young, N.P.', 'Russell, M.J.']",2021-10-28T19:23:55Z,2021-10-28T19:23:55Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89674,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['process optimization', 'aerosol based printing', 'film properties', 'capacitors']",Process Optimization of Aerosol Based Printing of Polyimide for Capacitor Application,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b95f08ee-e39c-4e5a-91c3-8c3e2b74ecf5/download,University of Texas at Austin,"Direct write printing approaches provide the opportunity for additive manufacturing
(AM) to impact the electronics industry. This class of technologies provides a path to cost
effectively print electronic components in low volume, high mix production. The printed
electronics technologies provide an opportunity to explore new materials, new processing
approaches and unique component configurations to alter the electronics industry. A new project
underway to explore printing of planar, nonplanar and three-dimensional capacitors will be
discussed. Aerosol based printing technologies applied to dielectric printing have demonstrated
the ability to print small features in three dimensions. This presentation will cover recent
research in optimizing process variables both with materials and deposition parameters to obtain
desirable film properties. This work will compare the film properties using the additive
manufacturing approach to traditional casting. Finally, this presentation will describe an
optimized process in detail and the rational for the processes chosen.",,,,,,
"['Hirsch, A.', 'Hecker, F.', 'Moritzer, E.']",2021-11-18T01:14:26Z,2021-11-18T01:14:26Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90387', 'http://dx.doi.org/10.26153/tsw/17308']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['arburg plastic freeforming', 'APF', 'optimization', 'process parameter', 'mechanical properties']",Process Parameter Optimization to Improve the Mechanical Properties of Arburg Plastic Freeformed Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0e735e75-6caa-4b9a-8494-874b3edd6a83/download,University of Texas at Austin,"The Arburg Plastic Freeforming (APF) is an additive manufacturing process that allows three-dimensional, thermoplastic components to be produced in layer by layer. The components are generated by
depositing fine, molten plastic droplets. One of the main advantages of the APF process is the open machine
control. Thus, the process parameters can be adapted and optimized for the individual applications.
The optimization is carried out on the basis of a variation of the process parameters using a statistical
design of experiments. Relevant process parameters are the layer thickness, the form factor, the raster and delta
angle as well as the overlap between the contour and the filling of a layer. In addition, the nozzle and build
chamber temperatures are varied. Using this procedure, the effects of the influencing parameters on the
mechanical properties and the interactions between the influencing parameters are analyzed and converted into
mathematical models. On the basis of the results and the models, guidelines will be developed to assist the user
of APF technology in the systematic process configuration for their own applications. The material used is ABS,
one of the most frequently used amorphous thermoplastics in additive manufacturing. The mechanical properties
are determined on the basis of tensile tests and the characteristic values tensile strength, elongation at break and
Young's modulus. The results should show the performance of the APF technology in regard to the mechanical
properties.",,,,,,
"['Yang, Y.', 'Janaki Ram, G. D.', 'Stucker, B. E.']",2020-03-05T20:21:25Z,2020-03-05T20:21:25Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80157', 'http://dx.doi.org/10.26153/tsw/7178']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic Consolidation,Process Parameters Optimization for Ultrasonically Consolidated Fiber-Reinforced Metal Matrix Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d4fcf669-c792-4f97-8560-a9214573f8af/download,,"As an emerging rapid prototyping technology, Ultrasonic Consolidation (UC) has
been used to successfully fabricate metal matrix composites (MMC). The intent of this
study is to identify the optimum combination of processing parameters, including
oscillation amplitude, welding speed, normal force, operating temperature and fiber
orientation, for manufacture of long fiber-reinforced MMCs. The experiments were
designed using the Taguchi method, and an L25 orthogonal array was utilized to
determine the influences of each parameter. SiC fibers of 0.1mm diameter were
successfully embedded into an Al 3003 metal matrix. Two methods were employed to
characterize the bonding between the fiber and matrix material: optical/electron
microscopy and push-out tests monitored by an acoustic emission (AE) sensor. SEM
images and data from push-out tests were analyzed and optimum combinations of
parameters were achieved.",,,,,,
"['Pinilla, J. Miguel', 'Kao, Ju-Hsien', 'Prinz, Fritz B.']",2019-02-20T17:15:42Z,2019-02-20T17:15:42Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73454', 'http://dx.doi.org/10.26153/tsw/606']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CNC machining', 'surface']",Process Planning and Automation for Additive-Subtractive Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1de24334-da86-41ad-8cd4-55371fa5d822/download,,"New additive-subtractive processes promise to enhance SFF capability from prototyping to true low-volume
production. However, to maintain the same degree of process automation as in currently available processes like
SLA or SLS, more sophisticated planning and execution systems need to be developed.
The system we present in this paper consists of two parts. The first is an off-line planner that decomposes a CAD
model into 3D manufacturable volumes called ""single-step geometries"", arranges these geometries into a graph
representation called"" adjacency graphs"", and automatically generates deposition and machining codes for each
single-step geometry. The second is an on-line system that handles asynchronous multi-part building, job-shop
scheduling, process control and run-time execution. Communication between these two stages is through a ""process
description language"".
The goal of this paper is to present a framework for planning and execution for additive/subtractive processes,
outline the issues involved in developing such an environment, and report on the progress made in this direction at
the Rapid Prototyping Laboratory of Stanford University.",,,,,,
"['Deuser, Brad', 'Tang, Lie', 'Geldmeiner, Jeff', 'Landers, Robert G.', 'Leu, Ming C.']",2021-10-05T13:25:43Z,2021-10-05T13:25:43Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88365', 'http://dx.doi.org/10.26153/tsw/15304']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'functionally graded materials', 'process planning', 'control system', 'Freeze-form Extrusion Fabrication']",Process Planning and Control for Functionally Graded Material Fabrication Using Freeze-Form Extrusion Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1cc81895-acf2-4899-a686-244700c7994b/download,University of Texas at Austin,"Using multiple materials in additive manufacturing technologies is critical for building
parts with functionally gradient geometries. In order to achieve a desired material gradient, an
advanced process planning and control system is required. This paper details the development of
a process planning method and control system for functionally graded material fabrication using
a triple extruder Freeze-form Extrusion Fabrication (FEF) system including motion code
generation, extruder dynamic modeling and control, and composition gradient control. The
effect that extruding multiple materials from a single orifice via static mixing has on the time
delay of the resulting mixture is taken into account for path planning, and this factor is
incorporated into integrating motion codes with extrusion commands. The effectiveness of the
proposed system is demonstrated by fabricating three-dimensional parts with desired gradient
compositions using multiple materials.",,,,,,
"['West, Aaron', 'Rosen, David W.']",2019-03-08T17:48:52Z,2019-03-08T17:48:52Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73573', 'http://dx.doi.org/10.26153/tsw/715']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Stereolithography', 'Process Planning']",Process Planning Based on User Preferences,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d5d0d424-03a0-4c1f-aa1c-8e36293e621e/download,,"Typical approaches to adaptive slicing in previous literature have typically used surface finish
requirements to control the slicing process. As a result, slice schemes improve the part's surface
quality, but do not enable explicit trade-offs between finish and build time. The purpose of this
article is to present a process planning method that enables the preferences of the user for surface
finish, build time, and accuracy to control how trade-offs are made in a process plan. A multiobjective goal formulation is used by this method to evaluate how well user preferences are met by
a process plan. This method consists of three modules, for determining part orientation, for slicing
the part, and for determining other parameter values. An example with several scenarios
representing different user preferences is provided to illustrate the process planning method.",,,,,,
"['Dwivedi, Rajeev', 'Kovacevic, Radovan']",2019-11-08T15:23:37Z,2019-11-08T15:23:37Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78321', 'http://dx.doi.org/10.26153/tsw/5408']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Multi-axis Deposition,Process Planning for Solid Freeform Fabrication Based on Laser-Additive Multi-axis Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61a1e414-619b-4460-9e98-bdebf43772c8/download,,"This paper describes a new approach for rapid prototyping based on volumetric
skeletonization. Contrary to most of the popular techniques for Solid Freeform
Fabrication (SSF) based on 2-1/2 -axis layering as planar slices, this approach suggests
the growth of the component along all three coordinate axes. While this approach offers
many advantages in terms of the elimination of the support structures for the reduction of
the staircase effects and the elimination of various post processes for the functional parts,
this approach also offers challenges towards process planning. For various complicated
shapes it may not be possible to generate the required shape using this approach;
however, a hybrid approach which also incorporates the deposition by layers, may offer
an optimum solution. Preliminary results are based on the successful laser-based
additive deposition along multiple g-vectors. The material properties and the problems of
possible porosities are still to be investigated. Advantages, process planning,
applications, experimental results, and the challenges of this new method are the subject
of this paper.","This work was financially supported by THECB (Texas Higher Education Coordinating
Board) Grants 003613-0022-1999 and 003613-0016-2001, NSF (National Science
Foundation) Grants DMI-9732848 and DMI-9809198 and by the US Department of
Education Grant P200A80806-98.",,,,,
"['Lynn, Charity M.', 'West, Aaron', 'Rosen, David W.']",2019-02-22T17:24:03Z,2019-02-22T17:24:03Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73462', 'http://dx.doi.org/10.26153/tsw/612']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'Stereolithography']",A Process Planning Method and Data Format for Achieving Tolerances in Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d38cdd9-c084-419a-9c85-457f4e2f9213/download,,"When building parts in a stereolithography apparatus (SLA), the user is faced with many decis!ons
regarding the setting of process variables. To 'achieve a set of tolera~ces as closely as pOSSIble,
relationships between part geometry, tolerances, and process v~nables ~ust be understood
quantitatively. This paper presents a method for SLA process plannIng that IS based on response
surface methodology and multi-objective optimization, where the response surfaces capture these
relationships. These response surfaces were generated by extensive design-of-experiment studies
for a variety of geometries. An annotated STL data format is also presented that enables the
inclusion of tolerance and surface information in fatetted representations. Application of the data
format and process planning method is illustrated on one part.",,,,,,
"['Jariwala, Amit S.', 'Jones, Harrison', 'Kwatra, Abhishek', 'Rosen, David W.']",2021-10-07T15:35:45Z,2021-10-07T15:35:45Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88483', 'http://dx.doi.org/10.26153/tsw/15417']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Exposure Controlled Projection Lithography', 'process planning', 'lens shaped structure', 'flat transparent substrates']",Process Planning Method for Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/88b211a5-c463-436e-b8ed-33b948ee16d0/download,University of Texas at Austin,"An Exposure Controlled Projection Lithography (ECPL) process with the ability to cure
lens shaped structures on transparent substrates is presented. This process can be used to create
microlenses and micro fluidic channels on flat or curved substrates. Incident radiation, patterned
by a dynamic mask, passes through a transparent substrate to cure photopolymer resin that grows
progressively from the substrate surface. A resin response model which incorporates the effects
of oxygen inhibition during photopolymerization is used to formulate a process planning method
for ECPL. This process planning method is validated for fabricating lens shaped structure on flat
transparent substrates using the ECPL system.",,,,,,
"['Limaye, Ameya', 'Rosen, David']",2020-03-09T14:23:37Z,2020-03-09T14:23:37Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80183', 'http://dx.doi.org/10.26153/tsw/7202']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Mask Projection Stereolithography,Process Planning to Build Mask Projection Stereolithography Parts with Accurate Vertical Dimensions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91348463-fc1b-4de8-85f2-1151a5ff23cb/download,,"Mask Projection Stereolithography (MPSLA) is a high resolution manufacturing process
that builds parts layer by layer in a photopolymer. In this paper, we formulate a process planning
method to cure MPSLA parts with accurate vertical dimensions. To this effect, we have
formulated and validated the “Layer cure” model that models the thickness of a cured layer as a
transient phenomenon, in which, the thickness of the layer being cured increases continuously
throughout the duration of exposure. We have shown that for longer durations of exposures, such
as those common with MPSLA systems, cure depth varies linearly with exposure. We have also
quantified the effect of diffusion of radicals on the cure depth when discrete exposure doses, as
opposed to a single continuous exposure dose, are used to cure layers.
Using this work, we have formulated and validated the “Print through” model that
computes the extra curing that would occur when multiple layers are cured over each other.
We have implemented the Print through model to simulate the profile of a down facing surface
of a test part and validated the simulation result by building the test part on our MPSLA system.",,,,,,
"['Niino, Toshiki', 'Oizumi, Shunsuke', 'Sato, Kazuki']",2021-09-23T22:57:56Z,2021-09-23T22:57:56Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88049', 'http://dx.doi.org/10.26153/tsw/14990']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['laser sintering process', 'inorganic filler', '3D tissue engineering scaffold']",Process Resolution of Laser Sintering Process Using Plastic Powder Containing Inorganic Filler at a High Rate,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e801ef41-373a-460c-8db3-6e9fe733cbcb/download,,"Research is being performed on a laser sintering process in which inorganic filler is
employed as porogen at a high content to fabricate highly porous three dimensional
tissue engineering scaffold. Previously, the scaffold, which included capillary like flow
channel network, was used in cell culture test, but obtained cell density was limited due
to insufficient fineness of the network structure. In the scaffold fabrication the author
experienced degradation of process resolution when inorganic filler was introduced at a
high content, but reasons for the low resolution has not been cleared. This paper
investigates the dominating cause of the low resolution. Discussion is focused on effect
of optical and thermal properties of filler. Experiments using transparent and opaque
fillers are performed, and existence of dominating effect of difference in the optical
property is denied. Experiments using thermally conductive solid filler and insulating
hollow filler is performed, and it is concluded that temperature conductivity is
dominating on process resolution.",,,,,,
"['Schmidt, J.', 'Dechet, M.A.', 'Gómez Bonilla, J.S.', 'Bück, A.', 'Peukert, W.']",2021-11-18T01:37:25Z,2021-11-18T01:37:25Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90395', 'http://dx.doi.org/10.26153/tsw/17316']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['process routes', 'process chains', 'blend powders', 'polybutylene terephthalate-polycarbonate', 'PBT-PC', 'selective laser sintering']",Process Routes Towards Novel Polybutylene Terephthalate – Polycarbonate Blend Powders for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9515b14-1f78-4090-a2ed-b30a5bb3a976/download,University of Texas at Austin,"Additive manufacturing techniques, such as powder bed fusion (PBF) of polymers, often referred to as
laser sintering (LS) or selective laser sintering (SLS), generate components directly from a CAD data set
without using a specific mold. The range of materials commercially available for SLS merely includes some
semi crystalline polymers, mainly polyamides. In this contribution two process chains to produce polybutylene
terephthalate (PBT) – polycarbonate (PC) blend particles and the respective dependencies of product
characteristics on process parameters are addressed. In the first recently proposed approach, blend powder
systems are produced via co-comminution of PBT and PC in a planetary ball mill and subsequent thermal
rounding of the obtained comminution product. This approach is compared to a route, where blend particles are
obtained by agglomeration of comminution products of the respective polymers obtained by wet grinding and
subsequent thermal rounding.",,,,,,
"['Birnbaum, Andrew', 'Aggarangsi, Pruk', 'Beuth, Jack']",2019-11-20T16:51:21Z,2019-11-20T16:51:21Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78483', 'http://dx.doi.org/10.26153/tsw/5568']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Process Scaling,Process Scaling and Transient Melt Pool Size Control in Laser-Based Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7d3a262-5f90-4fdc-963b-1705290f5f01/download,,"This modeling research considers two issues related to the control of melt pool size in
laser-based additive manufacturing processes. First, the problem of process size scale is
considered, with the goal of applying knowledge developed at one processing size scale (e.g. the
LENSTM process, using a 500 watt laser) to similar processes operating at larger scales (e.g. a 3
kilowatt system under development at South Dakota School of Mines and Technology). The
second problem considered is the transient behavior of melt pool size due to a step change in
laser power or velocity. Its primary application is to dynamic feedback control of melt pool size
by thermal imaging techniques, where model results specify power or velocity changes needed to
rapidly achieve a desired melt pool size. Both of these issues are addressed via a process map
approach developed by the authors and co-workers. This approach collapses results from a large
number of simulations over the full range of practical process variables into plots process
engineers can easily use.","This research was supported by the National Science Foundation Division of Design,
Manufacture and Industrial Innovation, through the Materials Processing and Manufacturing
Program, award number DMI-0200270.",,,,,
"['Brice, C.A.', 'Schwendner, K.l.', 'Mahaffey, D.W.', 'Moore, E.H.', 'Fraser, H.L.']",2019-03-15T16:13:50Z,2019-03-15T16:13:50Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73687', 'http://dx.doi.org/10.26153/tsw/829']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['manufacturing', 'technology']",Process Variable Effects on Laser Deposited Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf86ec6d-f87a-48ce-9c8b-c0a3c7ac3eca/download,,"An initial study ofthe processing parameters affecting deposition quality ofTi-6AI-4V was conducted using the LENSTM direct laser deposition system. The significant number ofprocess variables
presents a problem in determining relative effects. A few ofthe easily identifiable variables were isolated
and the deposits were characterized qualitatively by comparison oflayer adhesion, porosity, and dimensional accuracy. These characteristics were compared for each deposit while processing variables such as
laser power, travel speed, and hatch spacing were varied. The results led to the development of a
set of optimum processing conditions that produce a quality deposit.",,,,,,
"['Geis, J.', 'Reichwein, J.', 'Merschroth, H.', 'Kirchner, E.', 'Weigold, M.']",2023-03-29T16:27:38Z,2023-03-29T16:27:38Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117681', 'http://dx.doi.org/10.26153/tsw/44560']",eng,2022 International Solid Freeform Fabrication Symposium,Open,L-PBF,Process-controlled Grading of the Young's Modulus of AlSi10Mg Components Using L-PBF,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d95af48-dcf6-44bc-8d5a-9f805f93e18d/download,,"Laser Powder Bed Fusion (L-PBF) increases freedom in the design of components and is therefore 
well suited for the manufacturing of complex geometries tailored to their function. In addition, it is 
possible to influence the microstructural characteristics of the components by varying the process 
parameters during the L-PBF process. This allows shifting the load from areas with high stresses to less 
heavily loaded areas in order to exploit the full potential of the material. For this purpose, the process 
window in which the Young‘s modulus of the material AlSi10Mg can be varied was investigated. 
Subsequently, test geometries were analyzed by finite element method with respect to their critical 
component areas and a design for grading the Young‘s modulus to distribute stress more uniformly was 
developed. These specimens were then manufactured and compared with components manufactured using 
homogeneous parameters.",,,,,,
"['Budde, L.', 'Schwarz, N.', 'Hermsdorf, J.', 'Kaierle, S.', 'Overmeyer, L.']",2024-03-26T23:21:30Z,2024-03-26T23:21:30Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124448', 'https://doi.org/10.26153/tsw/51056']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['direct energy deposition', 'laser deposition', 'wiring', 'alloy', 'additive manufacturing']",PROCESS-INTEGRATED ALLOY ADJUSTMENT IN LASER DEPOSITION WELDING WITH TWO WIRES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c2c92688-ea4d-4ae1-a1ca-278ec2340a70/download,University of Texas at Austin,"For Direct Energy Deposition (DED) with wire as filler material, the material selection is
mostly limited to commercially available welding wires. This limits the achievable material
properties for cladding and Additive Manufacturing purposes. Using a coaxial deposition welding
head, in which two different wires can be fed and controlled individually, the alloy composition
can be adjusted in the common process zone in-situ.
In this study, the two wire materials AISI 316L and ER 70S-6 are used in different mixing ratios
to fabricate single weld seams. The different mixing ratios are achieved by varying the wire feed
rates. The material content in the weld is varied between 0% and 100% in 20% steps. The weld
seams are examined with regard to the distribution of alloying elements, hardness and
microstructure. Homogeneous mixing of the two materials was achieved at all mixing ratios. At a
content of 40% or more of ER 70S-6 in the weld seam, there was a drastic change in the
microstructure and a significant increase in hardness. The microstructure changed from austenitic
to ferritic-pearlitic, which was accompanied by an increase in hardness from 170 HV0.1 to
428 HV0.1.",,,,,,
"['Agarwal, Kuldeep', 'Houser, Matthew', 'Vangapally, Sairam', 'Vulli, Arun Kumar']",2021-11-02T15:49:01Z,2021-11-02T15:49:01Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89834,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['nylon-fiberglass', 'process parameters', 'mechanical properties', 'Taguchi design of experiments', 'design of experiments', 'additive manufacturing']",Process-Property Relationships in Additive Manufacturing of Nylon-Fiberglass Composites Using Taguchi Design of Experiments,Conference paper,https://repositories.lib.utexas.edu//bitstreams/57e94b15-b829-4266-b50a-e95eb3b2163d/download,University of Texas at Austin,"Composite Filament Fabrication (CFF) process, similar to Fused Deposition Modeling
(FDM) can extrude a fiber along with a plastic. The process has two nozzles, one that can
extrude Nylon and another that can extrude a fiber such as Fiberglass, Kevlar or Carbon Fiber.
The mechanical properties of the parts produced by this process are dependent on the process
parameters. To determine the effect of these process parameters and design parts for optimal
properties, the relationship needs to be determined. This research works with Nylon-Fiberglass
composite material. This study focuses on five different process parameters and their effect on
mechanical properties such as tensile strength, elastic modulus and elongation to fracture. 36
experiments based on Taguchi design of experiments methodology are conducted and the
analysis of variance of the results is used to find the important parameters. The results show that
some process parameters are more significant than others in affecting the mechanical properties.
It is found that the fiber volume % in the composite plays the most significant role in the
mechanical properties.",,,,,,
"['Lado, Lionardo', 'Ataollahi, Saeed', 'Yadollahi, Aref', 'Mahtabi, Mohammad J.']",2023-01-26T15:25:54Z,2023-01-26T15:25:54Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117316', 'http://dx.doi.org/10.26153/tsw/44197']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Microstructure-sensitive fatigue', 'Additive manufacturing', 'Ti-6Al-4V', 'EBM', 'LENS', 'SLM']",Process-Specific Microstructure-Sensitive Modeling of Fatigue in Additively Manufactured Ti-6Al-4V Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/341f7b4e-c1c1-45f0-acd1-7d14392a57be/download,,"Thanks to its high strength-to-weight ratio and corrosion resistance, Ti-6Al-4V has gained a lot 
of attention in additive manufacturing (AM) of complex parts with aerospace and medical 
applications. The realistic loading condition in these applications is mostly cyclic, thus fatigue 
failure is the main mode of failure. On the other hand, due to presence of local defects in the current 
state of AM materials, the main challenge with AM of metallic parts is their fatigue resistance and 
durability, being much lower than the conventional counterparts. In this study, a simplified 
microstructure-sensitive fatigue (MSF) approach was developed to model the fatigue life of AM 
Ti-6Al-4V specimens by incorporating microstructural features and defect properties, such as 
grain size, pore size and pores nearest neighbors. The studied AM methods include Laser 
Engineered Net Shaping (LENS), Electron Beam Melting (EBM), and Selective Laser Melting 
(SLM). Each of these processes use different approaches in constructing the three-dimensional 
object, yielding in different microstructure of the final part. For this work, microstructural data 
were collected from previous experimental studies. Scanning Electron Microscopy (SEM) images 
were used to examine the fracture surfaces of the AM specimens and determine the defects 
responsible for fatigue failure. With an emphasis on the microstructurally small crack growth, 
model parameters were calibrated for fatigue data for different AM processes, while keeping 
process-independent parameters as constant. The results showed that a simplified MSD fatigue 
model with limited number of process-dependent governing parameters can be calibrated for each 
set of data.",,,,,,
"['Lado, Lionardo', 'Ataollahi, Saeed', 'Yadollah, Aref', 'Mahtabi, Mohammad J.']",2023-01-09T19:31:58Z,2023-01-09T19:31:58Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117171', 'http://dx.doi.org/10.26153/tsw/44052']",,2022 International Solid Freeform Fabrication Symposium,Open,"['microstructure-sensitive fatigue', 'Additive manufacturing', 'Ti-6Al-4V', 'EBM', 'LENS', 'SLM']",Process-specific Microstructure-sensitive Modeling of Fatigue in Additively Manufactured Ti-6Al-4V Alloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ccf1e46e-d840-4e88-97a6-01692f350777/download,,"Thanks to its high strength-to-weight ratio and corrosion resistance, Ti-6Al-4V has gained a lot
of attention in additive manufacturing (AM) of complex parts with aerospace and medical
applications. The realistic loading condition in these applications is mostly cyclic, thus fatigue
failure is the main mode of failure. On the other hand, due to presence of local defects in the current
state of AM materials, the main challenge with AM of metallic parts is their fatigue resistance and
durability, being much lower than the conventional counterparts. In this study, a simplified
microstructure-sensitive fatigue (MSF) approach was developed to model the fatigue life of AM
Ti-6Al-4V specimens by incorporating microstructural features and defect properties, such as
grain size, pore size and pores nearest neighbors. The studied AM methods include Laser
Engineered Net Shaping (LENS), Electron Beam Melting (EBM), and Selective Laser Melting
(SLM). Each of these processes use different approaches in constructing the three-dimensional
object, yielding in different microstructure of the final part. For this work, microstructural data
were collected from previous experimental studies. Scanning Electron Microscopy (SEM) images
were used to examine the fracture surfaces of the AM specimens and determine the defects
responsible for fatigue failure. With an emphasis on the microstructurally small crack growth,
model parameters were calibrated for fatigue data for different AM processes, while keeping
process-independent parameters as constant. The results showed that a simplified MSD fatigue
model with limited number of process-dependent governing parameters can be calibrated for each
set of data.",,,,,,
"['Karg, M.', 'Ahuja, B.', 'Kuryntsev, S.', 'Gorunov, A.', 'Schmidt, M.']",2021-10-12T22:50:12Z,2021-10-12T22:50:12Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88762', 'http://dx.doi.org/10.26153/tsw/15696']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Laser Beam Melting', 'powder bed', 'aluminum-copper alloys', 'AW-2022', 'AW-2024', 'Additive Manufacturing']",Processability of high strength Aluminum-Copper alloys AW-2022 and 2024 by Laser Beam Melting in Powder Bed,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b3206b3-fd34-4901-9040-5398be5af7ac/download,University of Texas at Austin,"Additive Manufacturing offers geometric freedom excellently suited for topology
optimized light weight designs. Ideally these should be produced from materials of high strength
to weight ratio such as aluminium-copper alloys. Yet these are considered unsuitable for welding.
With Laser Beam Melting of Metals in powder bed (LBM), the only class of aluminium alloys
widely processed is that of aluminium-silicon alloys, which are easily weldable and castable, too.
In this contribution we present results of LBM high-strength aluminium-copper alloys AW-2022
and AW-2024 under variation of laser power, scan speed and hatch distance. We achieved
relative densities well above 99 %. We analyzed thin walls, compared process windows as well
as microstructures observed using etched metallographic microsections. We analyzed the
chemical constitution of powders and produced samples using ICP-OES.",,,,,,
"['Singer, C.', 'Platt, S.', 'Horn, M.', 'Binder, M.', 'Piechotta, M.', 'Wegner, J.', 'Kleszczynski, S.', 'Seidel, C.', 'Witt, G.', 'Schilp, J.']",2021-12-06T21:31:41Z,2021-12-06T21:31:41Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90678', 'http://dx.doi.org/10.26153/tsw/17597']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['processability', 'laser-based powder bed fusion', 'PBF-LB', 'soda-lime glass']",Processability of Soda-Lime Glass in Laser-Based Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/97f8cbce-21a2-46b6-a7fe-0cd65b06288e/download,University of Texas at Austin,"Processing of electrically insulating materials with high temperature resistance is a major
challenge in laser-based powder bed fusion (PBF-LB). Glasses form a promising material class, which
also offers the potential for manufacturing optical or electronic components while having high chemical
resistance. Therefore, this paper investigates the processability of soda-lime glass in conventional PBF-LB machines using Yb:YAG and CO2 lasers. Firstly, the flow properties and particle shape of the glass
powder were inspected. Secondly, the influence of laser power, scan velocity, layer height and hatch
distance as well as exposure pattern on the manufacturing of single tracks, single layers, and finally 3-
D-parts was investigated. Furthermore, an increase of the temperature of the platform range between
250 to 600 °C resulted in increasing relative density. Despite the higher absorptivity of soda lime glass
in the wavelength range of the CO2 laser, manufacturing of 3-D-parts was only possible using a
Yb:YAG laser due to insufficient laser power of the former beam source.",,,,,,
"['Gupta, Ankit', 'Hasanov, Seymur', 'Fidan, Ismail']",2021-11-18T16:37:58Z,2021-11-18T16:37:58Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90420', 'http://dx.doi.org/10.26153/tsw/17341']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'PMC', 'SF', 'tensile strength', '3D printing', 'microhardness']",Processing and Characterization of 3D-Printed Polymer Matrix Composites Reinforced with Discontinuous Fibers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/39ef9c26-d12f-42c2-9202-0d59534b3d26/download,University of Texas at Austin,"The objective of this study is to fabricate discontinuous fiber (short fiber) reinforced polymer
matrix composite material (CM) by additive manufacturing (AM) technology using single extruder
3D printer. For this study, short carbon fibers (diameter = 7.2μm, length = 150μm) reinforced
filaments were extruded with fiber concentrations of 3% - 7.5% in volume. Input process
parameters used for 3D printing to obtain good quality short carbon fiber (SCF) reinforced polymer
specimens are reinforcement percentage and printing speed by fixing nozzle temperature, layer
thickness, bed temperature and print orientation. It was analyzed that the surface characteristics
and mechanical performance of 3D printed samples are greatly influenced by varying input process
parameters. Scanning electron microscopy was performed to observe microstructural behavior of
3D printed samples. Tensile strength, ductility, and toughness were examined to validate the
adhesiveness of the matrix and reinforcement. From the microhardness test, it was observed that
the hardness properties are significantly affected by increasing the reinforcement percentage. The
results obtained in this study could be quite useful in fabricating polymer matrix composites
(PMCs) with improved overall characteristics for applications in automotive industry and medical
field.",,,,,,
"['Jiang, Kaiyi', 'Guo, Yanling', 'Bourell, David L.']",2021-10-13T19:41:51Z,2021-10-13T19:41:51Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88772', 'http://dx.doi.org/10.26153/tsw/15706']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'eucalyptus-polyamide 12', 'EPA12', 'wood powder']",Processing and Characterizations of Eucalyptus-PA12 Composite by Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7209b72b-016d-4828-b2fb-b9247893158c/download,University of Texas at Austin,"To meet the existing requirements to make Laser Sintering (LS) technology more economical
and environmentally friendly, a new type of low cost sustainable material (eucalyptus-polyamide
12 (EPA12) composite) was developed. This paper presents initial research into the LS PA12
with wood powder additions.
EPA12 mixed in a ratio of 1:2 by volume has been shown to be extremely processable by LS.
Before sintering experiments, thermal conductivity (which is an important component in
understanding and optimizing the processing of laser sintering EPA 12) was measured. During
LS processing, a variety of laser powers were chosen to investigate the effect of the energy input
on the densification, mechanical properties and forming accuracy of the material. The dispersion
of eucalyptus in the LS specimens of the composite powder was examined by scanning electron
microscopy (SEM). The microstructure of sintered EPA12 was observed. By comparing the
microstructures, observable differences based on varying levels of laser power were also present.
The maximum tensile strength and the flexure strength of prototypes are 3.7 MPa and 38 MPa,
respectively. These values increased from the minimum with increased energy input. On the
contrary, the forming accuracy was high at a relatively low laser power.",,,,,,
"['Xiong, Y.', 'Smugeresky, J. E.', 'Lavernia, E. J.', 'Schoenung, J. M.']",2020-03-10T17:39:57Z,2020-03-10T17:39:57Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80237', 'http://dx.doi.org/10.26153/tsw/7256']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Laser Engineered Net Shaping,Processing and Microstructure of WC-CO Cermets by Laser Engineering Net Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2481f2cc-3d15-41ff-87eb-cd06c64142f6/download,,"Submicron-sized tungsten carbide-cobalt (WC-Co) powder and nanostructured WC-Co
powder were applied to make thick wall samples by the Laser Engineered Net Shaping (LENS®)
process. It was found that decomposition and decarburization of WC was limited during laser
deposition because of the features of the LENS® process: high cooling rate, short heating time,
and low oxygen concentration. The effects of working distance, as well as laser power, powder
feed rate, and traverse speed on microstructure were studied in this paper. Thermal behavior
leading to the observed microstructures that result from the variations in the processing
parameters was investigated in detail",,,,,,
"['He, Yinfeng', 'Kilsby, Sam', 'Tuck, Chris', 'Wildman, Ricky', 'Christie, Steven', 'Edmonson, Steven', 'Yang, Hongyi']",2021-10-07T17:38:53Z,2021-10-07T17:38:53Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88491', 'http://dx.doi.org/10.26153/tsw/15425']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['biodegradable Polycaprolactone', '3D printing', 'biodegradable processing', 'PCL']",Processing Biodegradable Polycaprolactone through 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/71065317-cec8-4c12-9553-80ec068f62e8/download,University of Texas at Austin,"An initial study of processing biodegradable Polycaprolactone (PCL) through 3D
printing technology was conducted using Fujifilm Dimatix DMP-2800 material printer. The aim
of this work was to investigate a potential method of preparing and processing biodegradable
polycaprolactone through 3D printing. PCL inks with a concentration of 5wt% and 10wt% were
prepared to investigate their processability. The influences of waveform peak height, time gap,
printing voltage, droplet velocity, substrate temperature and droplet spacing on PCL ink droplet
formation as well as final deposition quality were investigated. Multi-layer PCL structures were
printed and characterized with the geometric quality of deposited PCL measured using a Talysurf
2000 and Bruker ContourGT-I. It was found that PCL solvent ink can reach relative stable
droplet formation and deposition when plate temperature was 30 ºC and droplet velocity was
6m/s. Printed PCL solvent ink showed ‘coffee ring’ effect after solidification. When deposition
droplet spacing equals to 40µm, printed PCL film showed the lowest surface roughness.",,,,,,
"['Spierings, A.B.', 'Bauer, T.', 'Dawson, K.', 'Colella, A.', 'Wegener, K.']",2021-10-20T22:40:25Z,2021-10-20T22:40:25Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89379,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'additive manufacturing', 'ODS materials', 'microstructure']",Processing ODS Modified IN-625 Using Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e80a9e3d-acf7-45e5-875c-5e7d07dd6852/download,University of Texas at Austin,"Increasing the operating temperatures of power plant turbine generators is a universal method
to increase the efficiency of steam and gas turbines. However, operating a plant at higher
temperatures poses extreme challenges to the materials used, especially regarding oxidation,
creep, thermal fatigue- and stress-corrosion cracking. The EU-OXIGEN project addresses
these issues by the development of novel processing routes for ODS-modified materials, as
this class of materials offers exceptionally high temperature strength, oxidation and corrosion
resistance at temperatures exceeding 900°C. Additive manufacturing processes such as
Selective Laser Melting are considered to enable their successful processing. First results on
density of SLM-processed, mechanically alloyed ODS-modified Inconel-625 superalloy
powders, are presented and compared to the processing conditions and results of gas atomized
conventional Inconel-625 powders. Whereas for IN625 a wide and stable processing window
was found, significant differences for the ODS variant in terms of the required laser energy
input to reach density values >99% are found. Microstructural analysis of precipitates lead to
the conclusion that the milling process for ODS variant is key to achieve good quality
materials and results.",,,,,,
"['Bose, Susmita', 'Avila, Marisol', 'Bandyopadhyay, Amit']",2019-02-27T17:39:20Z,2019-02-27T17:39:20Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73507', 'http://dx.doi.org/10.26153/tsw/657']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'bioceramic implants']",Processing of Bioceramic Implants Via Fused Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/efcd328a-4100-4a54-afb1-ed94f0443336/download,,"Porous ceramic structures have long been a subject of investigation as bone sl..bstitute.
Most of these porous structures are typically made by techniques that result .randomly arranged
pores with a wide variety of pore sizes. In recent years, SFF methods are being used for the
fabrication of porous bioceramic implants. Porous ceramic structures have been fabricated using
indirect route where a .polymeric mold is fitst created via fused deposition process. The mold
was then infiltrated with ceramic slurry, dried. and ·then subjected to a binder bum out and
sintering cycle. In this paper, processing of 3D honeycomb porous alumina ceramic structures
and some.initial mechanical properties for bone implants will be discussed.",,,,,,
"['Greer, Chad', 'McLaurin, Juli', 'Ogale, Amod A.']",2018-11-14T17:43:51Z,2018-11-14T17:43:51Z,1996,Mechanical Engineering,doi:10.15781/T2028PZ9Z,http://hdl.handle.net/2152/70248,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['ADPU', '3D photolithography', 'pure resins']",Processing of Carbon Fiber Reinforced Composites by Three Dimensional Photolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a72cacbe-deb2-4232-ba93-44fae8bc8296/download,,"The reinforcement of photoresins with continuous carbon fibers is discussed in this
paper. The processing was conducted in an automated desktop photolithography unit
(ADPU) developed and built in-house. Continuous fibers were added in situ to the
photoresin to obtain composite samples containing over 20 vol% of the fibers. The tensile
strength of these composites improved by at least a factor of 2 as compared to that of the
pure photoresins. It is also noted that the photoresin could be partially cured to develop
sufficient green strength in the composite samples even though the fibers are opaque to
ultraviolet radiation. These results indicate the potential of this technique to produce
functional composite components in conjunction with a 3-D photolithography apparatus.",,,,,,
"['Campanelli, Carlo', 'Wildman, Ricky D.', 'Tuck, Christopher J.']",2021-11-11T16:13:08Z,2021-11-11T16:13:08Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90232', 'http://dx.doi.org/10.26153/tsw/17153']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['part processing', 'fluoropolymers', 'laser sintering']",Processing of High Performance Fluoropolymers by Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/33dcf6a0-4114-4276-8ddb-50cf40a12c82/download,University of Texas at Austin,"One of the main limitations of laser sintering (LS) is its narrow material portfolio.
Fluoropolymers are a family of polymers with outstanding properties such as wide service
temperatures (−260 °C - +260 °C), excellent resistance to chemicals, sunlight, flames, and
weathering without the addition of stabilizers, plasticizers or fillers. In this study, fluoropolymers
such as perfluoroalkoxy (PFA) and polychlorotrifluoroethylene (PCTFE) have been used in laser
sintering. PFA and PCTFE have melting temperatures of 304 °C and 210 °C respectively which
make them challenging to process. Our results demonstrate the feasibility of these materials in LS
and that warping was the major issue encountered due to the relatively low powder bed temperature
of ∼182 °C. We illustrate how particle size, additives, and thermal conditioning affect the powder
flow and how the warping can be decreased by utilizing a modified build plate, and different scan
strategies and part orientations. Flat sheets were successfully produced with potential use in
membrane-based applications.",,,,,,
"['Spierings, A.B.', 'Leinenbach, C.', 'Kenel, C.', 'Wegener, K.']",2021-10-13T21:33:31Z,2021-10-13T21:33:31Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88787', 'http://dx.doi.org/10.26153/tsw/15721']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'hybrid materials', 'metal matrix composite', 'diamonds', 'microstructure']",Processing of Metal-Diamond-Composites using Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4801699-6900-421b-accc-ff3f3e8ad7d9/download,University of Texas at Austin,"Powder-bed based additive manufacturing processes such as Selective Laser Melting
(SLM) offer a huge degree of freedom, both in terms of part design and material options. In
that respect, mixtures of different materials in powder form can offer new ways for the
manufacture of materials with tailored properties for special applications. A promising field
of applications is e.g. additive manufacturing of metal-based cutting or grinding tools with
incorporated hard phases. For that purpose a feasibility study was performed concerning
SLM of a Cu-Sn-Ti alloy powder, which is usually used for active brazing of ceramics and
superhard materials, containing 10-20 vol.-% artificial, Ni-coated mono-crystalline diamonds.
Even though the processing parameters were not yet optimized, stable specimens containing
intact diamonds could be produced. First results on density and microstructure are presented
and discussed.",,,,,,
"['Safari, A.', 'Danforth, S. C.', 'Panda, R. K.', 'McNulty, T. F.', 'Mohammadi, F.', 'Bandyopadhyay, A.']",2018-12-05T20:00:15Z,2018-12-05T20:00:15Z,1997,Mechanical Engineering,doi:10.15781/T2S17TC9D,http://hdl.handle.net/2152/71408,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Piezoelectricity', 'centrosymmetric']",Processing of Novel Piezoelectric Transducers Via SFF,Conference paper,https://repositories.lib.utexas.edu//bitstreams/52dc9af2-25be-4731-8e53-3b7b46a396a5/download,,"Piezoelectric ceramics and ceramic/polYmer composites exhibiting conventional and novel
designs were fabricated using Solid Freeform Fabrication (SFF) techniques. SFF is used to
develop and optimize numerous transducer designs with simple and complex shapes without using
any part specific tools or dies. Fused Deposition ofCeramics (FDC), Fused Deposition Modeling
(FDMTM), and Sanders Prototyping (SPI) techniques were used to develop lead-zirconate-titanate
(PZT) novel ceramic structures via: (1) direct fabrication and (2) indirect fabrication routes. For
the direct fabrication route, green PZT ceramic preforms consisting of 50-55 volume fraction of
powder with RU binders were prepared by FDC and used for piezocomposites. For the indirect
route, SPI and FDMTM techniques were used build the polymer prototype or mold, and the
ceramic parts were fabricated from the molds/prototypes using (a) lost mold and (b) soft tooling
processes. Among the various ceramics and composites processed via the direct and indirect
processes are dome shaped actuators, 3D honeycomb, ladder, annular, rods, tubes and various
oriented PZT fiber structures. This presentation will review the processing routes for design,
development and optimization of piezoelectric ceramics and ceramic/polYmer composites for
transducer applications.",,,,,,
"['Bandyopadhyay, A.', 'Panda, R. K.', 'Janas, V. F.', 'Danforth, S. C.', 'Safari, A.']",2018-11-14T17:13:17Z,2018-11-14T17:13:17Z,1996,Mechanical Engineering,doi:10.15781/T2MS3KM76,http://hdl.handle.net/2152/70243,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['FDC', 'Piezolectric materials', 'polymer materials']",Processing of Piezocomposites via Solid Freeform Fabrication (SFF),Conference paper,https://repositories.lib.utexas.edu//bitstreams/45613c8a-89fe-4163-9deb-d8837023bdf7/download,,"Fused Deposition and Sanders prototyping were used to manufacture PZT-polymer
composites with various architecture for transducer applications. Two separate processing
routes, direct and indirect, were utilized to make these composites. In the direct processing
route, Fused Deposition of ceramics (FDC) was used to form green ceramic structures. For the
indirect processing route, molds ofthe negative of the structures were made using FDM™ and
Sanders prototyping techniques. Molds were infiltrated with a PZT slurry and dried. These
structures were subjected to a binder bum out cycle to remove the mold polymer and binder.
Structures were sintered and infiltrated with an acoustic epoxy, cut, polished and poled for
electro-mechanical characterization. Among the various composites produced via the direct
and indirect processes were: 3D honeycomb, 3-3 ladder, 2-2 annular and 1-3 rods. Composites
with features as fine as 50 f.lm were manufactured and characterized. Properties ofpiezoelectric
composites produced by SFF techniques compared to conventionally processed composites.",,,,,,
"['Streek, A.', 'Regenfuss, P.', 'Ullmann, F.', 'Hartwig, L.', 'Ebert, R.', 'Exner, H.']",2020-02-28T21:16:04Z,2020-02-28T21:16:04Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80123', 'http://dx.doi.org/10.26153/tsw/7144']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser micro sintering,Processing of Silicon Carbide by Laser Micro Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6421febb-2f3c-4011-b6b8-d9ece4487483/download,,"Silicon carbide – a solid with covalent bonds - is conventionally synthesized via the Acheson
process. Usually solid bodies of silicon carbide with definite shapes are generated from the
grained material via hot isostatic pressing or liquid phase sintering. Both processes are
conducted under well-controlled temperature regimes. Applying the freeform fabrication
technique “Laser Micro Sintering” poses a big challenge to experimental skill due to the nonequilibrium conditions that are characteristic features of laser material processing.
 Successive layers SiC layers with a thickness of 1μm were processed with coherent
radiation of 1064 nm. The specific behavior of two different silicon carbide powders - one of
them blended with additives - are reported along with interpretational approaches.",,,,,,
"['Das, Suman', 'Wohlert, Martin', 'Beaman, Joseph J.', 'Bourell, David L.']",2019-02-26T16:46:25Z,2019-02-26T16:46:25Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73485', 'http://dx.doi.org/10.26153/tsw/635']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'Direct fabrication']",Processing of Titanium Net Shapes by SLS/HIP,Conference paper,https://repositories.lib.utexas.edu//bitstreams/61e29f2c-9147-4eb1-8318-af8f9a8bedb2/download,,"SLS/HIP is a hybrid direct laser fabrication method that combines the strengths of
selective laser sintering (SLS) and hot isostatic pressing (HIP). SLS can produce complex
shaped metal components with an integral, gas impermeable skin. These components can then
be directly post-processed to full density by containerless HIP. SLS/HIP is envisioned as a rapid,
low cost replacement for conventional metal can HIP processing. The advantages of freeform
fabrication combined with in-situ HIP encapsulation include ability to perform containerless HIP, no adverse container-powder interactions, reduced pre-processing time, and fewer postprocessing steps compared to conventional HIP of canned parts. SLS/HIP is currently being
developed for Inconel 625 superalloyand Ti-6AI-4V. This paper focuses on microstructure and
mechanical properties of SLS processed and HIP post-processed Ti-6AI-4V. SLS/HIP
technology for Ti-6Al-4V was demonstrated by fabricating a subscale AIM-9 missile guidance
section housing to specification. This work is funded jointly by DARPA and ONR under contract
N00014-95-C-0139 titled ""Low Cost Metal Processing Using SLS/HIP.""",,,,,,
"['Khan, M.', 'Dickens, P. M.']",2020-03-11T15:31:30Z,2020-03-11T15:31:30Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80252', 'http://dx.doi.org/10.26153/tsw/7271']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,Processing Parameters for Selective Laser Melting (SLM) of Gold,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9f2393da-5491-42e6-b2e8-38c41e3dd57d/download,,"Research into laser processing of different metals has enabled Solid Freeform Fabrication (SFF)
processes to produce parts for a wide variety of applications. However, less focus has been made
on the processing of precious metals. Currently little research has been reported on the
processing of precious metals and alloys using the Selective Laser Melting (SLM) process. Here
we present an initial investigation into the processing of 24 carat gold (Au) powder using a SLM
system. Gold powder was tested for apparent density, tap density, particle shape and size
distribution. A quality check of the specimen was carried out using a Scanning Electron
Microscope (SEM) for sinterability and occurrence of porosity. Significant processing
parameters were also identified.",,,,,,
"['Zong, G.', 'Tompkins, J.V.', 'Thissell, W.R.', 'Sajot, E.', 'Marcus, H.L.']",2018-04-17T18:55:08Z,2018-04-17T18:55:08Z,1991,Mechanical Engineering,doi:10.15781/T22Z1364K,http://hdl.handle.net/2152/64353,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SALD', 'pyrolytic']",Processing Problems Associated with Gas Phase Solid Freeform Fabrication Using Pyrolytic Selective Area Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a43ba5e-b967-4668-85db-1017b1677e16/download,,"Concerns critical to selective area laser deposition are discussed. Variables affecting
deposition rate, dimensional control, and surface uniformity are analyzed. Localized growth
results in undesirable morphology, and contributing factors are cited. Catalytic powders increase
nucleation rate and provide superior temperature profiles resulting in good surface uniformity.
Specific process control devices are investigated.",,,,,,
"['Schumacher, Christian', 'Schöppner, Volker', 'Gnaase, Stefan']",2021-11-10T21:59:12Z,2021-11-10T21:59:12Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90190', 'http://dx.doi.org/10.26153/tsw/17111']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['short fiber-reinforced filaments', 'fiber reinforced polymers', 'fused deposition modeling', 'processing']",Processing Short Fiber-Reinforced Polymers in the Fused Deposition Modeling Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c3498048-8643-4add-87fa-e99e0bc9e492/download,University of Texas at Austin,"By adding fibers to a polymer matrix, a reinforcement of the material can be achieved. Short
fiber-reinforced polymers can easily be processed by the Fused Deposition Modeling (FDM)
process without major modifications to the processing machine. For instance, short fiber-reinforced
filaments can be processed to produce short fiber-reinforced components in the FDM process. In
many other additive manufacturing processes this is not possible at this low cost. The choice of the
matrix material, fiber type, fiber length and fiber orientation have a major influence on the
properties of the produced component. In this paper, short fiber-reinforced filaments are processed
by the FDM process. The processing properties and the resulting part properties are investigated
with regard to fiber-specific influences. Additionally, the effects of different strand geometries and
thus changed flow fields on the fiber orientation and mechanical part properties are investigated.",,,,,,
"['Hattiangadi, Ashwin', 'Bandyopadhyay, Amit']",2019-03-13T16:22:31Z,2019-03-13T16:22:31Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73642', 'http://dx.doi.org/10.26153/tsw/784']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['ceramic', 'Porous Hydroxyapatite']","Processing, Characterization and Modeling of Non-Random Porous Ceramic Structures",Conference paper,https://repositories.lib.utexas.edu//bitstreams/1674283b-653f-4d15-ac65-bda01c4c157c/download,,"Processing of non-random porous ceramic structures via fused deposition process is
discussed. structures are characterized experimentally and statistically based on their
compressive strength. Finite element modeling is used to understand the effect of stress
concentration leading to the strength degradation ofthese brittle elastic solids.",,,,,,
"['Prinz, F.B.', 'Weiss, L.E.', 'Amon, C.H.', 'Beuth, J.L.']",2018-10-05T17:07:39Z,2018-10-05T17:07:39Z,1995,Mechanical Engineering,doi:10.15781/T20G3HH4W,http://hdl.handle.net/2152/68716,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SDM', 'CNC machining', 'SFF']","Processing, Thermal and Mechanical Issues in Shape Deposition Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/153d495c-54bc-4da7-be99-30af47781d44/download,,"An overview of Shape Deposition Manufacturing (SDM) is presented, detailing
manufacturing, thermal and mechanical issues of concern in making it a commercially viable
method for creating arbitrarily shaped three-dimensional metal parts. SDM is a layered
manufacturing process which combines the benefits of solid freeform fabrication and other
processing operations, such as multi-axis CNC machining. This manufacturing process makes
possible the fabrication of multi-material layers, structures of arbitrary geometric complexity,
artifacts with controlled microstructures, and the embedding of electronic components and sensors
in conformal shape structures. Important issues toward the production of high quality objects are
the creation of inter-layer metallurgical bonding through substrate remelting, the control of cooling
rates of both the substrate and the deposition material, and the minimization of residual thermal
stress effects. Brief descriptions of thermal and mechanical modeling aspects of the process are
given. Because SDM involves molten metal deposition, an understanding of thermal aspects of the
process is crucial. Current thermal modeling of the process is centered on the issue of localized
remelting of previously deposited material by newly deposited molten droplets. Residual stress
build-up is inherent to any manufacturing process based on successive deposition of molten
material. Current mechanics modeling is centered on the issues of residual stress build-up and
residual stress-driven debonding between deposited layers.",,,,,,
"['Kempen, K.', 'Thijs, L.', 'Vrancken, B.', 'Buls, S.', 'Van Humbeeck, J.', 'Kruth, J.-P.']",2021-10-07T15:44:25Z,2021-10-07T15:44:25Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88485', 'http://dx.doi.org/10.26153/tsw/15419']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Selective Laser Melting', 'M2 parts', 'pre-heating', 'baseplate', 'crack-free', 'high density']","Producing Crack-Free, High Density M2 HSS Parts by Selective Laser Melting: Pre-Heating the Baseplate",Conference paper,https://repositories.lib.utexas.edu//bitstreams/03977b07-9b7b-4e54-8133-4d12ca545c18/download,University of Texas at Austin,"Cracks and delamination, resulting from residual stresses are a barrier in the world of Additive
Manufacturing and Selective Laser Melting (SLM) that prohibits the use of many metals in this field. By preheating the baseplate, thermal gradients are lowered and stresses can be reduced. In this work, some initial tests
were performed with M2 Tool Steel. Results show that pre-heating enables the production of dense M2 parts.
The influence of pre-heating on density and mechanical and physical properties is investigated. The paper
shows many promising results for the production of SLM parts in materials that are very sensitive to crack
formation and delamination. When using a pre-heating of 200°C, crack-free parts were produced with a relative
density of 99.8%.",,,,,,
"['Liou, Frank', 'Leu, Ming']",2020-03-10T16:33:22Z,2020-03-10T16:33:22Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80227', 'http://dx.doi.org/10.26153/tsw/7246']",eng,2008 International Solid Freeform Fabrication Symposium,Open,freeform fabrication,Product Focused Freeform Fabrication Education,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a4bf3b7-4adf-4f62-a56a-bc549bfcaa6e/download,,"Presented in this paper is our experience of teaching freeform fabrication to students at
the Missouri University of Science and Technology, and to high school students and
teachers. The emphasis of the curriculum is exposing students to rapid product
development technologies with the goal of creating awareness to emerging career
opportunities in CAD/CAM. Starting from solid modeling, principles of freeform
fabrication, to applications of rapid prototyping and manufacturing in industry sponsored
product development projects, students can learn in-depth freeform fabrication
technologies. Interactive course content with hands-on experience for product
development is the key towards the success of the program.",,,,,,
"Carleberg, Per",2018-10-03T15:54:34Z,2018-10-03T15:54:34Z,1994,Mechanical Engineering,doi:10.15781/T20R9MP3X,http://hdl.handle.net/2152/68654,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SFF System', 'selective laser sintering', 'laser power and laser thickness']",Product Model Driven Direct Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ad9b9e0-93cf-4587-9d18-12b1d9ea15ce/download,,"The input to the freeform fabrication process is essentially geometric data, raw
material, material data and process parameters. Optimal process parameters depend
upon current material and the part geometry.
This paper describes an research approach in which all necessary input including
process parameters are obtained or derived from the product model. The part geometry
with its process parameters is transferred as a STEP model to the SFF system.
In the SFF system this model is converted to the internal format, coupled to the
process parameters. The approach is exemplified with the SLS machine from DTM
as SFF system.",,,,,,
"['Reiher, T.', 'Koch, R.']",2021-11-01T21:53:32Z,2021-11-01T21:53:32Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89769,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['product optimization', 'topology optimization', 'part optimiization', 'additive manufacturing']",Product Optimization with and for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d8318c8-bb2d-4a6f-be0e-9d0bb88cc6ff/download,University of Texas at Austin,"Additive Manufacturing offers a great potential for the optimization of products. Therefore different
approaches are feasible to exploit these potentials for elaborating optimal solutions. For example these include
optimization of weight or stiffness of structural components as well as the integration of functions and other
entities of assemblies. Note, however, that additive manufacturing processes have process specific limitations.
Products, components and assemblies, as well as procedures for the design and production preparation must be
optimized with regard to a successful additive manufacturing.
The use of already known tools for the optimization and design needs to be reconsidered and adapted to the
additive manufacturing. This also includes the production planning with component orientation in build chamber
as well as a necessary quality management system.
This paper shows several ways for product optimization with additive manufacturing, often based on topology
optimization, and procedures for information gathering, decision making and shape determination for part
optimization for Additive Manufacturing.",,,,,,
"['Stucker, Brent E.', 'Bradley, Walter L.', 'Norasetthekul, Somchin', 'Eubank, Philip T.']",2018-11-02T16:19:53Z,2018-11-02T16:19:53Z,1995,Mechanical Engineering,doi:10.15781/T2X05XZ21,http://hdl.handle.net/2152/69335,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['EDM', 'Rapid prototyping', 'tool production']",The Production of Electrical Discharge Machining Electrodes Using SLS: Preliminary Results,Conference paper,https://repositories.lib.utexas.edu//bitstreams/49cc7c9c-ce71-4908-a3b6-3b550c2e4fd2/download,,"Electrical discharge machining (EDM) has become common place in the tool and die industry
as an alternative to conventional machining and now accounts for 2% ofworldwide machiningl
, with
a substantially greater concentration ofuse in the tool making industry.EDM has the advantage of
allowing tool steel billets to be heat treated to full hardness before the cavity is produced, obviating
the need for heat treatment after machining--a step that often results in the loss of dimensional
accuracy due to distortion in the quenching from high temperature austenite to martensite at room
temperature. Any material with less than 1 ohm-m ofelectrical resistivity, regardless ofhardness, can
be machined using EDM. 1 EDM also allows the convenient production of complex shapes in the tool
cavity, as complex topographies can often be more easily machined on the electrode than inside a
cavity. Even certain simple shapes such as rectangular or square cavities are far easier to produce
using EDM than conventional machining.
EDM machining, however, is precluded from many market niches by the relatively high cost
ofelectrode production In visiting with approximately sixty representatives from the EDM industry,
we have learned that the cost of electrode fabrication is often greater than 50%, and sometimes as
great as 80%, ofthe total cost offabricating a die using EDM. 2
,3 The wear ratio ofthe two most
commonly used electrode materials, graphite and copper, requires the use ofmultiple electrodes in
the production of each cavity, because the electrode wears away and loses its initial shape too
quickly. Thus, the replacement ofgraphite and copper electrodes with electrodes made ofmaterials
which are more resistant to electric spark erosion would significantly improve the cost effectiveness
ofEDM tool production.
Many tools have multiple cavities that use a different electrode for each separate cavity
because it is easier to machine several small, simply-shaped electrodes than it is to machine one large,
complex electrode. This requires a greater total sink time in the EDM machine, since multiple cavities
are machined sequentially rather than simultaneously. The ability to create a large, complex electrode
quickly would greatly reduce the time and money spent in tool production using EDM.
If the rapid prototyping technology4-7 that has emerged during the past ten years could be
utilized to fabricate EDM electrodes, the cost of producing electrodes with complex shapes could be
substantially reduced, and new material systems which are difficult to machine could be utilized for
the electrodes. Complex electrodes capable of making multiple imprints/cavities in dies
simultaneously could be fabricated just as easily as simple electrodes using rapid prototyping
equipment, which would increase the precision ofthe cavities' placement relative to one another,
278
dramatically reducing the EDM machine time required. A die which might, for instance, require as
many as 15 imprints, which are now done sequentially, could be done in one EDM operation,
reducing the time in the EDM machine and increasing the precision of placement ofthe imprints
relative to one another. 3 This would be a significant contribution to the tool and die industry.
Texas A&M University has undertaken research to produce EDM electrodes using rapid
prototyping. Specifically, the development of a process for rapid prototyping ofEDM electrodes,
using selective laser sintering (SLS) ofpolYmer coated intermetallic powders which are subsequently
infiltrated with a highly conductive metal, is being investigated.",,,,,,
"['Sachs, Emanuel', 'Allen, Samuel', 'Cima, Michael', 'Wylonis, Edward', 'Guo, Honglin']",2018-11-08T15:47:25Z,2018-11-08T15:47:25Z,1995,Mechanical Engineering,doi:10.15781/T22N5036C,http://hdl.handle.net/2152/69894,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['3D Printing', 'postprocessing', 'unbound powder']",Production of Injection Molding Tooling with Conformal Cooling Channels using The Three Dimensional Printing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b53c2b4-1b22-46e9-9c6e-433a801947aa/download,,"Three Dimensional Printing is a desktop manufacturing process in which
powdered materials are deposited in layers and selectively joined with binder from an ink-jet style
printhead. Unbound powder is removed upon process completion, leaving a three dimensional
part. Stainless steel injection molding inserts have been created from metal powder with the 3DP
process.
The freedom to create internal geometry by the use of the 3D-Printing process allows for the
fabrication of molds with complex internal cooling passages. Tooling was developed with cooling
channels designed to be conformal to the molding cavity. A finite difference simulation was
constructed to study conformal channel design.
A direct comparison of the mold surface temperature during the injection cycle of a 3D Printed
mold with conformal channels and a mold machined with conventional straight channels was
completed. The conformal passages produced with the 3DP process provide the ability to
accurately control the temperature of the molding cavity throughout the process cycle. Surface
temperature measurements demonstrated that the inserts with conformal cooling channels exhibited
a more uniform surface temperature than the inserts machined with straight channels.
Issues such as powder removal and post processing of green parts with small cooling
channels were investigated.",,,,,,
"['Pridham, M.S.', 'Thomson, G.A.', 'Menon, U', 'Koch, M']",2018-09-26T18:49:48Z,2018-09-26T18:49:48Z,1994,Mechanical Engineering,doi:10.15781/T2TM72K6Q,http://hdl.handle.net/2152/68583,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Laminated Prototyping', 'Laser Forming', 'Rapid Prototyping']",Production of Metal Prototypes Using a High Powered Laser Machining Centre,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7e93e72d-47e4-4d05-982a-2b8ada4eef6c/download,,"The established commercially available rapid prototyping techniques are now well
known throughout the manufacturing community. They are able to produce high quality,
accurate prototypes, but are limited largely to processing polymer, wax or paper materials.
Where a metal part is required, then a further process step, such as investment casting using
the prototype part as a pattern is required. As a further point most of the above systems are
high capital cost dedicated pieces of equipment.
This paper describes the use of laser machining centres as rapid prototyping tools in
the areas of, laminated prototyping, using both paper and metal, and laser forming.",,,,,,
"['Schmidt, Jochen', 'Gómez Bonilla, Juan', 'Sachs, Marius', 'Lanz, Lydia', 'Wudy, Katrin', 'Wirth, Karl-Ernst', 'Drummer, Dietmar', 'Peukert, Wolfgang']",2021-10-28T14:28:34Z,2021-10-28T14:28:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89649,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['process route', 'glass composites', 'polybutylene terephthalate', 'selective laser sintering']",Production of Polybutylene Terephthalate Glass Composite Powders and Characterization for Processing in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac4ed357-89cb-4aba-bb8b-b0c19aaae78a/download,University of Texas at Austin,"Additive manufacturing techniques, such as selective laser melting of plastics, generate components
directly from a CAD data set without using a specific mould. The range of materials commercially available for
selective laser sintering merely includes some semi crystalline polymers, mainly polyamides. In this
contribution a recently proposed process route (grinding and rounding) which allows for production of spherical
polymer micro particles is applied to glass-filled polybutylene terephthalate. Composite powders of good
flowability are obtained. Process relevant material characteristics like powder flowability and thermal properties
are investigated. The influence of filler content on grinding behavior and resulting materials properties is
discussed.",,,,,,
"['Dalgarno, K.W.', 'Stewart, T.D.', 'Childs, T.H.C.']",2019-09-20T18:30:45Z,2019-09-20T18:30:45Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75928', 'http://dx.doi.org/10.26153/tsw/3027']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Polymer,Production Tooling for Polymer Components Via The DTM RapidSteel Process 125,Conference paper,https://repositories.lib.utexas.edu//bitstreams/565c6381-af8a-4c0c-8388-ed3e2e4528c9/download,,"This paper reports the results of a study examining the potential of layer manufacturing processes to deliver production tooling for polymer manufacture, with the DTM RapidSteel process used to provide the tooling. Four main areas were addressed during the study: wear, mechanical strength, accuracy, and productivity, with each area examined through analytical
studies and industrial trials. An overview of the results from both the analytical and in company experimental studies are presented.",,,,,,
"['Jahnke, U.', 'Bornefeld, P.A.', 'Koch, R.']",2021-11-01T22:31:25Z,2021-11-01T22:31:25Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89784,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['traceability', 'markings', 'product marking', 'additive manufacturing', 'Industry 4.0']",Production-Integrated Markings for Traceability of AM Parts in the Context of Industry 4.0,Conference paper,https://repositories.lib.utexas.edu//bitstreams/738ddd09-9213-4178-b951-812aead63bd3/download,University of Texas at Austin,"Traceability is often mentioned as one fundamental requirement to reach the vision of Industry 4.0,
the next industrial revolution. As Additive Manufacturing (AM) is a technology with high relevance in
the scope of Industry 4.0 this paper focuses on production-integrated markings for traceability of
additively manufactured parts. Even industries that are not focusing on products with critical
functionality using markings for quality management and liability exclusion can benefit a lot from
identifiability of products. Markings can be understood as a kind of individualization of parts. As
individualization does not increase production costs when using AM and the effort for integration of
markings can be minimized by software in particular for high batch production, product marking
should be an obligatory process step. This paper comprises various applications that can be achieved
due to markings as well as different ways to embed a marking at least partly automatically.",,,,,,
"['Khanzadeh, Mojtaba', 'Jafari Marandi, Ruholla', 'Tootooni, M. Samie', 'Bian, Linkan', 'Smith, Brian', 'Rao, Prahalad']",2021-10-28T19:26:37Z,2021-10-28T19:26:37Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89675,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['geometric accuracy', 'self-organizing map', 'additive manufacturing']",Profiling and Optimizing the Geometric Accuracy of Additively Manufactured Components via Self-Organizing Map,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d0360f2-5953-4c20-b669-243072a226a4/download,University of Texas at Austin,"One main challenge of additive manufacturing is the lack of geometric accuracy of the parts.
Part geometry measurements generated using Next Engine 3D scanners yields an extremely large
amounts of data. The generated data is so large, that it is difficult to characterize and quantify the
geometric accuracy of the part directly. Self-Organizing Map is utilized to investigate the major
types of geometric deviations.",,,,,,
"['Zheng, Yong', 'Choi, Sangeun', 'Mathewson, Brian', 'Newman, Wyatt']",2018-11-14T18:06:37Z,2018-11-14T18:06:37Z,1996,Mechanical Engineering,doi:10.15781/T2Z31P79X,http://hdl.handle.net/2152/70256,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAM-LEM', 'CAD']","Progress in Computer-Aided Manufacturing of Laminated Engineering Materials Utilizing Thick, Tangent-Cut Layers",Conference paper,https://repositories.lib.utexas.edu//bitstreams/27dea143-ff71-4ee8-94fc-5d5c4f21bd3e/download,,"This paper presents recent progress in extending the CAM-LEM process to 5-axis laser cutting
for fabrication of laminated engineering components directly from sheet materials. The present
extensions enable construction of layered objects from thicker layers by cutting all layers with
shaped edges. Use of thicker material layers offers the opportunity for faster build rates and/or
improved surface finish. We describe our system and present initial experimental results in
utilizing tangent-cut layers for object fabrication. Utilizing surface-tangent information
introduces new computational complexities in converting CAD descriptions into machine
process control commands. We present an algorithm for achieving this conversion, and we
illustrate its successful performance.",,,,,,
"['Sachs, Emanuel', 'Allen, Samuel', 'Guo, Honglin', 'Banos, Javier', 'Cima, Michael', 'Serdy, James', 'Brancazio, David']",2018-11-28T21:23:35Z,2018-11-28T21:23:35Z,1997,Mechanical Engineering,doi:10.15781/T29P2WR9G,http://hdl.handle.net/2152/70331,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Harder tooling', 'Improvements in surface finish']","Progress on Tooling by 3D Printing; Conformal Cooling, Dimensional Control, Surface Finish and Hardness",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b04bccc9-18d1-4c42-aab0-e5c7538123cd/download,,"Three Dimensional Printing is being applied to the direct fabrication of tooling using metal
powders. This paper presents progress updates in four areas: i) thermal management using
conformal cooling and related work on enhanced heat transfer using surface textures, ii) data on
dimensional control, iii) ) improvements in surface finish, and iv) harder tooling.
Conformal cooling has demonstrated significantly improved performance in a production part
geometry with simultaneous gains in production rate and part quality obtained as measured against
conventional tooling. Surface textures printed on cooling channels have demonstrated 8X
enhancement of heat transfer over smooth channels.
A set of 18 tooling inserts was fabricated using hardenable stainless steel powder with a
resultant tooling hardness of 25-30 Rockwell C. Harder alloy systems are being designed with the
aid of computational thermodynamic tools which allow accurate prediction of the interaction of
powder and binder. Significant improvements in surface finish were obtained using improved
printing technology. Dimensional control of tools conformed well to the expected result of being
dominated by control of shrinkage and being predictable to within ±.25%.",,,,,,
"['Dutta, Deba', 'Kikuchi, Noboru', 'Papalambros, Panos', 'Prinz, Fritz B.', 'Weiss, Lee']",2018-04-19T16:04:20Z,2018-04-19T16:04:20Z,1992,Mechanical Engineering,doi:10.15781/T23R0Q985,http://hdl.handle.net/2152/64377,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering & Applied Mechanics', 'MAXWELL', 'MD']",Project MAXWELL: Towards Rapid Realization of Superior Products,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1226f259-66b5-44fc-b602-2ac8d6477fe5/download,,"We describe a new methodology for the design and manufacture of mechanical
components. The methodology is a synergism of a new, mathematically rigorous
procedure for the concurrent design of shape and material composition of components,
and a new manufacturing process called MD* for their realization. The concurrent design
strategy yields information about the global shape of the component and its material
composition. The fabrication of such designs with novel microstructural configurations
require unconventional manufacturing processes. MD* is a shape deposition process for
the free-form fabrication of parts from single or composite materials and is ideally suited
for realizing the aforementioned designs. Project MAXWELL, therefore, promotes the use
of layered manufacturing beyond prototyping tasks and offers the possibility of their
integration into the mainstream product development and fabrication process..",,,,,,
"['Chartoff, R.P.', 'Schultz, J.W.', 'Bhatt, J.', 'Ullett, J.S.']",2019-03-01T17:43:31Z,2019-03-01T17:43:31Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73521', 'http://dx.doi.org/10.26153/tsw/671']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['resins', 'molecular structure']",Properties of a High Temperature Liquid Crystal Stereolithography Resin,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ddbfa131-2504-48ca-bd8f-8f3239bb6578/download,,"A liquid crystal monomer has been developed that contains both acrylate and acetylene reactive
groups. The curing behavior and mechanical properties ofthe polymers formed from this monomer have
been characterized in this study. Complete cure can be carried out in two separate steps, combining both
photo and thermal polymerization. The initial photo- polymerization to form a robust ""green"" polymer
involves crosslinking through the acrylate groups and the subsequent thermal polymerization to increase
the crosslink density is accomplished by reaction of the acetylene groups. After the thermal postcure the
polymer has an unusually high glass transition, in excess of 300°C. In addition, the monomer exhibits an
ordered liquid crystalline (LC) phase. Photopolymerization while in the LC phase locks in the molecular
ordering. Mechanical property data and additional information on curing in both the isotropic and LC
phases are reviewed in the following presentation.",,,,,,
"['Lewis, Gary K.', 'Milewski, John O.', 'Thoma, DanB.', 'Nemec, RonB.']",2018-12-06T21:12:23Z,2018-12-06T21:12:23Z,1997,Mechanical Engineering,doi:10.15781/T2639KR65,http://hdl.handle.net/2152/71429,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['DLF process', 'cross-sectional layers']",Properties of Near-Net Shape Metallic Components Made by the Directed Light Fabrication Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fbfac1a0-9854-4ce8-9d90-340802869c2b/download,,,,,,,,
"['Li, Wenbin', 'Ghazanfari, Amir', 'McMillen, Devin', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Watts, Jeremy']",2021-10-27T23:33:48Z,2021-10-27T23:33:48Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89643,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['ceramic on-demand extrusion', 'zirconia components', 'ceramic parts']",Properties of Partially Stabilized Zirconia Components Fabricated by the Ceramic On-Demand Extrusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/086f0c86-8919-4400-9f37-dee902358797/download,University of Texas at Austin,"The Ceramic On-Demand Extrusion (CODE) process is a novel additive manufacturing
process for fabricating dense ceramic components from aqueous pastes of high solids loading. In
this study, 3 mol% Y2O3 stabilized tetragonal zirconia polycrystal (3Y-TZP) parts were
fabricated using the CODE process. The parts were then dried in a humidity controlled
environmental chamber and sintered under atmospheric pressure. Mechanical properties of the
sintered parts were examined using ASTM standard test techniques, including density, Young’s
modulus, flexural strength, Weibull modulus, fracture toughness and Vickers hardness. The
microstructure was analyzed, and grain size was measured using scanning electron microscopy.
The results compared with those from Direct Inkjet Printing, Selective Laser Sintering, and other
extrusion-based processes indicated that zirconia parts produced by CODE exhibit superior
mechanical properties among the additive manufacturing processes. Several example parts were
produced to demonstrate CODE’s capability for fabricating geometrically complex ceramic
parts.",,,,,,
"['Qi, Gang', 'Dai, Cheng', 'Rangarajan, Sriram', 'Wu, Suxing', 'Bandyopadhyay, Amit', 'Langrana, Noshir', 'Safari, Ahmad', 'Danforth, Stephen C.']",2018-12-05T20:10:50Z,2018-12-05T20:10:50Z,1997,Mechanical Engineering,doi:10.15781/T2HM5353R,http://hdl.handle.net/2152/71410,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'FDC']",Properties of RU955 Si3N4 Filament for Fused Deposition ofCeramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/01e28703-a3fe-436a-93a5-5b30c5bc3faf/download,,"One ofthe key elements in the FDC process is the development of ceramic loaded fusible filament. The filament is not
only material feed stock for deposition, but also serves as a piston to push the fused material through the FDC liquefier.
Therefore, the FDC filament has to meet several requirements. It should have enough flexibility to satisfy the automatic
feeding requirements, enough stiffness to carry the force for extrusion in the liquefier, and a low viscosity. A series of
binders developed at Rutgers University show promising properties and meet these requirements. However, the change
of filament properties with time and storage conditions was observed, and they dramatically influenced the FDC
process. Systematic experiments were carried out in order to understand filament aging and establish proper storage
conditions. The results indicate that moisture in the environment plays an important role in the filament aging.
Vacuum treatment at 30°C apparently accelerates the aging process. The mechanisms offilament aging and the method
offilament evaluation will be discussed.",,,,,,
"['Zhang, Shanshan', 'Dilip, Samuel', 'Yang, Li', 'Miyanaji, Hadi', 'Stucker, Brent']",2021-10-21T19:17:51Z,2021-10-21T19:17:51Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89427,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['cellular struts', 'process parameters', 'process orientation', 'selective laser melting', 'powder bed fusion', 'additive manufacturing']",Property Evaluation of Metal Cellular Strut Structures via Powder Bed Fusion AM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7113e701-7306-4132-abe4-3c46df3bece4/download,University of Texas at Austin,"Cellular structures are widely used in many engineering applications, because of their light weight, high
strength-to-weight ratio, high energy absorption, etc. Many previous research and development works
are largely focused on structural design, while the material properties are often over-simplified. In this
work, the relationships between process parameter and orientation on the geometrical and mechanical
characteristics of the cellular struts fabricated via selective laser melting (SLM) were investigated. The
results provide preliminary guidelines on the use of laser melting additive manufacturing process for the
fabrication of cellular strut structures.",,,,,,
"['Moylan, Shwan', 'Slotwinski, John', 'Cooke, April', 'Jurrens, Kevin', 'Donmez, M. Alkan']",2021-10-06T22:37:47Z,2021-10-06T22:37:47Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88462', 'http://dx.doi.org/10.26153/tsw/15399']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'standardization', 'test parts', 'test artifact']",Proposal for a Standardized Test Artifact for Additive Manufacturing Machines and Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5a48c9b9-0df0-4b77-8a9d-55b21d820d56/download,University of Texas at Austin,"Historically, standardized test parts are used to quantitatively evaluate the performance of a
machine or process. While several different additive manufacturing (AM) test parts have been
developed in the past, there are no current standard test parts. This paper reviews existing AM
test parts, discusses the purposes of the studies, and describes important features and
characteristics found in these test parts. A new test part intended for standardization is proposed.
This part incorporates the most useful features seen in previous test parts. These features are
designed to highlight process capabilities and test machine accuracy. The design has been
validated through builds by several AM processes.",,,,,,
"['Nassar, A.R.', 'Reutzel, E.W.']",2021-10-07T15:16:28Z,2021-10-07T15:16:28Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88476', 'http://dx.doi.org/10.26153/tsw/15411']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'XML-based file format', 'ASTM F291 standard', 'digital thread', 'automotive', 'aerospace', 'medical']",A Proposed Digital Thread for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/439cd274-e7ad-4424-8f93-1b84837f24b0/download,University of Texas at Austin,"Additive manufacturing (AM) has been explored by the automotive, aerospace and
medical industries for many years but has yet to achieve wide-spread acceptance. This is
partially due to the lack of standard frameworks for the exchange of data related to design,
modeling, build plan, monitoring, control, and verification. Here, a unified paradigm, built on
Extensible Markup language (XML) -based file formats and influenced by the ASTM F291
standard, is proposed, to record and transmit data at every stage of the AM process. This digital
thread contains all essential parameters, from design to testing of metal-based AM parts while
remaining accessible, traceable and extensible.",,,,,,
"['Gegesky, Megan', 'Liou, Frank', 'Newkirk, Joseph']",2021-10-28T19:03:53Z,2021-10-28T19:03:53Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89670,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fusion welding', 'friction stir', 'hybrid process', 'part build']",Proposed Hybrid Processes for Part Building Using Fusion Welding and Friction Stir Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b49f514d-8ffc-4068-9c48-3e6b3fbabe48/download,University of Texas at Austin,"It has been shown that a hybrid laser additive manufacturing and friction stir processing
can deposit components with forged-like structures. This paper reports a hybrid fusion welding
and friction stir process to create parts with quality structures. Combining traditional fusion
welding and friction stir processing techniques for non-weldable aluminum alloys could facilitate
the joining of difficult geometries in manufactured parts. This research illustrates mechanical
property changes for non-weldable and weldable aluminum alloys. The Vickers hardness, and
microhardness in the case of AA5052-H32, tensile strength and corrosion resistance of four
processing states: base material, fusion welded material, friction stir welded material, and friction
stir processed fusion welded material are studied for AA2024-T351, AA5052-H32, and AA7075-
T651. This technology has applications to part building for large parts such as landing gear, and
ship hulls; where traditional additive manufacturing processes would be excessively costly and
time consuming. By joining larger pieces by such a hybrid process, a near net shape approach can
be achieved on a large scale. This technology would remove the need for drilling and fastener use,
plausibly increasing the strength of large part joints with complex geometries.",,,,,,
"['Tang, H. H.', 'Yen, H. C.', 'Su, S. M.', 'Lin, Z. Y.']",2020-02-13T19:45:21Z,2020-02-13T19:45:21Z,9/1/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79968', 'http://dx.doi.org/10.26153/tsw/6993']",eng,2004 International Solid Freeform Fabrication Symposium,Open,layer manufacturing,Prospect of Making Ceramic Shell Mold by Ceramic Laser Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dcf9292a-7847-4c0e-8871-863dbd496bdf/download,,"Manufacturing prototypical castings by conventional investment casting not only takes
several weeks, but also is prohibitively expensive. Z Corporation in USA, EOS GmbH and
IPT in Germany employ the techniques of 3DP and SLS respectively to make directly ceramic
shell molds for metal castings. Although those techniques dramatically reduce time
expenditure and production cost, each layer cannot be thinner than 50 µm because of using
powder to pave layers. The dimensional accuracy and roughness of the castings still cannot
meet the specification of precision casting. Therefore, in this paper the ceramic laser fusion
(CLF) was used to pave layers. Each layer can be thinner than 25 µm, so that the step effect
can be diminished and the workpiece surface can be smoother; drying time will be shortened
dramatically. Moreover, the inherent solid-state support formed by green portion has the
capability of preventing upward and downward deformation of the scanned cross sections. In
order to make shell mold which meets the roughness requirement (Rq=3.048µm) of the
precision casting, following issues have to be further studied: (1) design a proper ceramic
shell mold structure, (2) design a paving chamber for paving a complete green layer which
can be easily collapsed, (3) cut down drying time, (4) optimize laser scanning process
parameters with the smallest distortion, (5) eliminate sunken area, (6) reduce layer thickness
to less than13µm, (7) control power to guarantee the energy uniformly absorbed by workpiece,
and (8) develop a method which can directly clean green portion in cavity from gate.",,,,,,
"['Jahnke, U.', 'Büsching, J.', 'Reiher, T.', 'Koch, R.']",2021-10-21T20:42:41Z,2021-10-21T20:42:41Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89442,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['protection measures', 'product piracy', 'additive manufacturing']",Protection Measures against Product Piracy and Application by the Use of AM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f24b0223-be6f-4371-acb5-cd07b54c344f/download,University of Texas at Austin,"Presently the implications Additive Manufacturing (AM) on intellectual properties are
discussed in public. Here AM is often mentioned as a driver for product piracy as it allows to
produce and to copy objects with any geometries. Imitators need a lot of information to copy
an object accurately. As reverse engineering has been identified as the most important
information source for product imitators, AM can also help to reduce the threat of product
piracy when correctly applied in the product development. Due to the layer wise production
process that allows the manufacturing of very complex shapes and geometries, the reverse-engineering process can be complicated by far. By this, quite contrary to the public opinion,
AM can increase the needed effort of imitators and strongly reduce the economic efficiency of
product piracy. This paper will show different protection measures and a methodological
approach of how to apply these measures to a product. Beside the protective effect some
measures allow a traceability of parts over the product’s lifecycle and thus support the quality
management of AM processes and additively produced parts.",,,,,,
"['Lennings, A.F.', 'Broek, J.J.', 'Horvath, I.', 'Smit, A.', 'Vergeest, J.S.M.']",2019-02-19T17:30:18Z,2019-02-19T17:30:18Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73433', 'http://dx.doi.org/10.26153/tsw/585']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'technology']",Prototyping Large-Sized Objects Using Freeform Thick Layers of Plastic Foam,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2c710ef-67c9-43a4-b41a-5d6800e8e48c/download,,"Current Rapid Prototyping systems are primarily aimed at small-sized objects containing many
shape details. In this paper a Rapid Prototyping technology is presented that is aimed at largesized objects having a complex, freeform outer shape. This new technology builds the model out
ofthick layers, each having freeform outside faces. The paper will present: an overview of current
methods to produce large prototypes, the basics of the new method, the technology used to
produce the layers, the toolpath planning and finally the overall system design.",,,,,,
"['Dordlofva, Christo', 'Törlind, Peter']",2021-11-08T22:53:31Z,2021-11-08T22:53:31Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90065', 'http://dx.doi.org/10.26153/tsw/16986']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'space application', 'qualification', 'product development process', 'manufacturing process development']",Qualification Challenges with Additive Manufacturing in Space Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ebb16fe-aa43-44d5-9cdf-67de9734bd38/download,University of Texas at Austin,"Additive Manufacturing (AM) has the potential to remove boundaries that traditional
manufacturing processes impose on engineering design work. The space industry pushes product
development and technology to its edge, and there can be a lot to gain by introducing AM.
However, the lack of established qualification procedures for AM parts has been highlighted,
especially for critical components. While the space industry sees an advantage in AM due to
expensive products in low volumes and long lead-times for traditional manufacturing processes
(e.g. casting), it also acknowledges the issue of qualifying mission critical parts within its strict
regulations. This paper focuses on the challenges with the qualification of AM in space
applications. A qualitative study is presented where conclusions have been drawn from
interviews within the aerospace industry. The results highlight important gaps that need to be
understood before AM can be introduced in critical components, and gives insight into
conventional component qualification.",,,,,,
"['Weeren, R. Van', 'Agarwala, M.', 'Jamalabad, V.R.', 'Bandyopadhyay, A.', 'Vaidyanathan, R.', 'Langrana, N.', 'Safari, A.', 'Whalen, P.', 'Danforth, S.C.', 'Ballard, C.']",2018-11-02T16:50:57Z,2018-11-02T16:50:57Z,1995,Mechanical Engineering,doi:10.15781/T2CZ32Q6D,http://hdl.handle.net/2152/69339,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SLS', 'SLA process']",Quality of Parts Processed by Fused Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/68b5450e-aa5f-4d71-8d86-7ad86991335e/download,,"FDMTM (fused deposition modeling) is a SFF technique for the fabrication of
polymer parts. Research is being conducted on the fabrication of ceramic parts by fused
deposition. In this study polymer and ceramic parts were made using a commercially
available FDMTM system, 3D Modeler, and the Quickslice™ software. These parts were
evaluated for processing defects.
Defects originate from the fused deposition process, from material characteristics,
or a combination thereof. Process defects, which are present in all polymer parts, are due
to current hardware, software and build strategy limitations. These same defects are seen
in ceramic parts fabricated by fused deposition of ceramics (FDC). Another set of defects
in ceramic parts is due to materials characteristics, i.e., non-uniformities in the feed stock
filaments, their mechanical and/or rheological properties.
The presence of defects in polymer or ceramic parts was studied using simple
build primitives (single roads) and parts in the green state. Parts were characterized for
their quality using SEM and optical microscopy.",,,,,,
"['Weaver, Jason', 'Barton, TJ', 'Jenkins, Derrik', 'Linn, John', 'Miles, Mike', 'Smith, Robert']",2021-11-04T20:10:08Z,2021-11-04T20:10:08Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90019', 'http://dx.doi.org/10.26153/16940']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['test artifact', 'accuracy', 'capabilities', 'concept laser', 'metal additive manufacturing', 'NIST']",Quantifying Accuracy of Metal Additive Processes Through a Standardized Test Artifact,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db1ab32c-1272-4423-bad5-bf6319715aea/download,University of Texas at Austin,"Two limitations of AM processes when compared to CNC subtractive processes are
reduced dimensional accuracy and rougher surface finish. Accuracy and surface finish of metal
additive processes, such as DMLS or SLM, are generally much looser than precision turning or
grinding processes. Because of this, it is important to have an understanding of an AM machine’s
capabilities—the designer must be satisfied with the tolerances and finishes possible, or additional
post-processing must be added. One way to examine the capabilities of an AM process is by
printing and measuring test artifacts. This paper examines a test artifact proposed by NIST that is
intended to demonstrate many different capabilities and types of accuracy. Three identical builds
are printed on a Concept Laser metal additive machine and measured. The capabilities of the
machine are quantified and discussed, along with additional recommendations for improving the
test structure design and the measurement process.",,,,,,
"['Limaye, Ameya', 'Rosen, David']",2020-02-14T15:51:43Z,2020-02-14T15:51:43Z,9/1/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79989', 'http://dx.doi.org/10.26153/tsw/7014']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Mask Projection Microstereolithography,Quantifying Dimensional Accuracy of a Mask Projection Micro Stereolithography System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63358a64-b94a-4d1e-8914-4ad79a421b47/download,,"Mask Projection Microstereolithography is capable for fabricating true three-dimensional
microparts and hence, holds promise as a potential micro-fabrication process for micro-machine
components. In this paper, the Mask Projection Micro-Stereolithography (MPµSLA) system
developed at the Rapid Prototyping and Manufacturing Institute at Georgia Institute of
Technology is presented. The dimensional accuracy of the system is improved by reducing its
process planning errors. To this effect, the MPµSLA process is mathematically modeled. In this
paper, the irradiance received by the resin surface is modeled as a function of the imaging system
parameters and the pattern displayed on the dynamic mask. The resin used in the system is
characterized to experimentally determine its working curve. This work enables us to compute
the dimensions of a single layer cured using our system. The analytical model is validated by
curing test layers on the system. The model computes layer dimensions within 5% error.",,,,,,
"['Park, Sang-in', 'Rosen, David W.']",2021-10-21T16:52:26Z,2021-10-21T16:52:26Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89403,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['as-fabricated voxel modeling', 'mechanical property degradation', 'material extrusion']",Quantifying Mechanical Property Degradation of Cellular Material Using As-Fabricated Voxel Modeling for the Material Extrusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7877551c-9867-4f79-83db-07c1eef4af37/download,University of Texas at Austin,"When fabricating cellular material using the material extrusion process, manufacturing
errors arise due to approximation of geometries during slicing and tool-path generation, as well
as the finite filament size. Moreover, since a cellular material generally consists of a large
number of structural elements such as struts and plates, it has large bounding surfaces to be
approximated during the AM process, which can increase manufacturing error. The errors
degrade the mechanical properties of a fabricated cellular material. In this paper, an as-fabricated
voxel modeling approach is proposed to quantify mechanical property degradation. An additively
manufactured strut is modeled using voxels based on material extrusion and its effective
structural characteristics such as a cross-sectional area and the second moment of area are
evaluated. The property degradation is assessed by comparing mechanical properties from tensile
tests and performing discrete homogenization with obtained structural characteristics.",,,,,,
"['Sinha, Swapnil', 'Meisel, Nicholas A.']",2021-11-11T15:43:56Z,2021-11-11T15:43:56Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90225', 'http://dx.doi.org/10.26153/tsw/17146']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['in-situ embedding', 'embedding orientation', 'flexural property', 'additive manufacturing']",Quantifying the Effect of Embedded Component Orientation on Flexural Properties in Additively Manufactured Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3cb8e44f-2393-4c5b-bd46-5994761713ae/download,University of Texas at Austin,"In-situ embedding with Additive Manufacturing (AM) enables a user to insert functional
components in a part by pausing the print, inserting the component into a specially designed cavity,
and then resuming the print. This introduces the capability to merge the reliable functionality of
external parts into AM structures, allowing multifunctional products to be manufactured in a single
build. Previous research has shown that process interruption introduces weaknesses at the paused
layer, and the presence of an embedding cavity further reduces the maximum tensile strength of
the part. The research presented in this paper expands this understanding by investigating the
impact of the process and design considerations for embedding on the strength of the material
extrusion parts. A cuboidal geometry is embedded with different orientations with a flush surface
at the paused layer, and tested for maximum bending strength. The findings help to further design
guidelines for embedding with material extrusion AM.",,,,,,
"['Moges, Tesfaye', 'Yan, Wentao', 'Lin, Stephen', 'Ameta, Gaurav', 'Fox, Jason', 'Witherell, Paul']",2021-11-15T21:07:32Z,2021-11-15T21:07:32Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90272', 'http://dx.doi.org/10.26153/tsw/17193']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'powder bed fusion', 'uncertainty quantification', 'melt pool model', 'design of experiments']",Quantifying Uncertainty in Laser Powder Bed Fusion Additive Manufacturing Models and Simulations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d944da48-668e-4752-96c5-39ce07d895d8/download,University of Texas at Austin,"Various sources of uncertainty that can potentially cause variability in the product quality
exist at different stages of the laser powder bed fusion (L-PBF) process. To implement
computational models and simulations for quality control and process optimization, quantitative
representation of their predictive accuracy is required. In this study, a methodology to estimate
uncertainties in L-PBF models and simulations is presented. The sources of uncertainty, including
those due to modeling assumptions, numerical approximation, input parameters, and measurement
error, are discussed in detail and quantified for low and high-fidelity melt pool simulation models.
A design of experiments (DOE) approach is leveraged to quantify uncertainty due to input
parameters and investigate their effects on output quantities of interest (QoIs). The result of this
work is essential for understanding the tradeoffs in model fidelity and guiding the selection of a
model suitable for its intended purpose.",,,,,,
"['Sojiphan, K.', 'Babu, S.S.', 'Yu, X.', 'Vogel, S.C.']",2021-10-05T19:29:53Z,2021-10-05T19:29:53Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88418', 'http://dx.doi.org/10.26153/tsw/15357']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['very high power ultrasonic additive manufacturing', 'crystallographic texture', 'heat treatments', 'aluminum alloy']",Quantitative Evaluation of Crystallographic Texture in Aluminum Alloy Builds Fabricated by Very High Power Ultrasonic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/564d0285-5b25-44be-8622-6a45ef235640/download,University of Texas at Austin,"Very high power ultrasonic additive manufacturing (VHPUAM) has shown good bond
quality over traditional ultrasonic consolidation processes. However, the stability of
microstructure in bulk and interface regions is unknown. Our earlier research showed a large
difference in grain growth kinetics between bulk and interface regions. Therefore, we have
performed in-situ studies of crystallographic texture evolution using a neutron beam line, before,
during, and after heat treatment at 343oC for 2 hours. Shear texture in the as-received condition
was found to be stronger with higher vibration amplitudes. We also observed rapid reduction of
rolling textures in the initial material and presence of shear textures even after heat treatment.",,,,,,
"['Denton, Karl R.', 'Jacobs, Paul F.']",2018-09-27T19:56:13Z,2018-09-27T19:56:13Z,1994,Mechanical Engineering,doi:10.15781/T26Q1T23T,http://hdl.handle.net/2152/68609,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', '3D Printing', 'StereoLithography']",QuickCast™ & Rapid Tooling: A Case History at Ford Motor Company,Conference paper,https://repositories.lib.utexas.edu//bitstreams/29973e4f-4e50-49eb-aa3f-b0a8174a545c/download,,,,,,,,
"['Büsching, J.', 'Koch, R.']",2021-11-08T22:28:03Z,2021-11-08T22:28:03Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90056', 'http://dx.doi.org/10.26153/tsw/16977']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['ramp-up-management', 'additive manufacturing', 'technology integration', 'business process', 'business infrastructure', 'OptiAMix']",Ramp-Up-Management in Additive Manufacturing – Technology Integration in Existing Business Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e483d4d-edbf-4415-975d-9e27c5145693/download,University of Texas at Austin,"In conventional manufacturing, ramp-up-management describes the planning and
organization of the period between finished product development and the achievement of full
production capacity for defined products. This classification has to be adapted and restructured by
means of product independent and tool-free production in additive manufacturing. Therefore ramp-up-management already starts with decisions on the extent of the use of additive manufacturing,
includes the building of technology-know-how as well as the technology integration into processes
and infrastructure of the company and ends with the attainment of a sufficient process reliability
for the AM-machine. This paper focuses on technology integration in processes and infrastructure,
which is part of the German research project OptiAMix. In this project, new systems for process
state analysis adapted to additive manufacturing and methods for the optimal integration of additive
manufacturing are developed. Furthermore ways of using the synergies of existing infrastructures
and new innovative production technologies are determined.",,,,,,
"['Perez, Mireya A.', 'Ramos, Jorge', 'Espalin, David', 'Hossain, Mohammad S.', 'Wicker, Ryan B.']",2021-10-12T19:06:21Z,2021-10-12T19:06:21Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88723', 'http://dx.doi.org/10.26153/tsw/15657']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['desktop additive manufacturing', 'additive manufacturing', '3D printing', 'ranking model']",Ranking Model for 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03fe05ac-6eaf-4609-adeb-1d90eab03fc8/download,University of Texas at Austin,"The capabilities of desktop additive manufacturing (AM) machines were evaluated based
on the ability to produce a standard component. This work also developed a model/method for
evaluating and ranking AM technologies based on select criteria that can facilitate purchasing
decisions. A standard part was adapted and printed on each machine, and evaluated in various
ways to provide machine-specific input data for the model. The research highlights the
differences between AM units and suggests a method by which to evaluate the differences. With
the rapid proliferation of desktop additive manufacturing units, a quantitative ranking system
was developed to rate these units so that the consumer, for example, can use this model to assist
with decision making during purchase. Although the focus of the work was on desktop systems,
the approach can be applied across other AM technologies.",,,,,,
"['Brooks, W.', 'Sutcliffe, C.', 'Cantwell, W.', 'Todd, J.', 'Mines, R.']",2020-02-21T15:06:42Z,2020-02-21T15:06:42Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80060', 'http://dx.doi.org/10.26153/tsw/7082']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,Rapid Design and Manufacture of Ultralight Cellular Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82d18056-4877-4e1e-934f-f855538623b0/download,,"This paper details the design, manufacture and testing of regular metallic lattice structures
with unit cell sizes in the range 0.8mm to 5mm and truss elements of 100-500 µm in diameter [1].
The structures were manufactured using Selective Laser Melting (SLM) technology from 316L
stainless steel. Compression tests have shown yield loadings of over 3.5kN despite being only
18mm by 18mm by 10mm in height, the results are favourably comparable to current
commercially available metallic foams. Software has been developed that creates slice files
without the use of CAD software or STL files and is capable of producing lattices within a
volume defined by a STL file.",,,,,,
"['Kadakia, Samit R.', 'Novac, Andrei S.', 'Roosendaal, Mark D. Van', 'Thomas, Charles L.', 'Smith, Norman T.', 'Balogh, Matthew']",2018-11-30T15:04:55Z,2018-11-30T15:04:55Z,1997,Mechanical Engineering,doi:10.15781/T23N2108K,http://hdl.handle.net/2152/70592,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['RP technique', 'Rapid Prototyping']",Rapid Fabrication of Disposable Fixtures for Correct Assembly of Split Build Rapid Prototyped Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b5cc8a93-874b-4fbc-97a7-a43d5c59f196/download,,"The size of part that can be produced in a single build on any ofthe commercially
available Rapid Prototyping systems is limited by the size ofthe particular machine's
build envelope. Parts which exceed the dimensions ofthe build envelope are split into
sections that fit the machine's envelope and these sections are fabricated separately.
Assembly ofthe sections into an accurate three dimensional object often requires the
creation of a fixture. This fixture ensures correct positional and angular orientation ofthe
sections during assembly. This paper discusses the fabrication ofsuch fixtures using
Shapemaker II, a Solid Freeform Fabrication process developed at the University ofUtah.
Using Shapemaker II, large fixtures (4 ft. by 8 ft. or even larger) can be created in just a
few hours. While the fixture is reusable, given the low cost ofthe fixture, it can be
considered a throwaway item.",,,,,,
"['Yang, D. Y.', 'Kim, H. C.', 'Lee, S. H.', 'Ahn, D. G.', 'Park, S. K.']",2020-02-20T19:52:42Z,2020-02-20T19:52:42Z,8/29/05,Mechanical Engineering,,https://hdl.handle.net/2152/80045,eng,2005 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'Large-sized solid shape', 'VLM-ST process', 'MHC process']",Rapid Fabrication of Large-sized Solid Shape using Variable Lamination Manufacturing and Multi-functional Hotwire Cutting System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/658ad111-687f-410e-af99-53c58584f3d5/download,,"Rapid prototyping (RP) technologies have been widely used to reduce the lead-time and
development cost of new products. The VLM-ST process has been developed to overcome the
currently developed RP technologies such as a large building time, a high building cost, an
additional post-processing and a large apparatus cost. However, the VLM-ST process has the
limitation of fabricated model size (VLM300: 297×210 mm, VLM400: 420×297 mm) and the
limitation of slope angle when the large-sized model more than 600 × 600 × 600 mm or
axisymmetric shape is fabricated. The objective of this paper is to develop a multi-functional
hotwire cutting system (MHC) using EPS-foam block or sheet as the working material in order to
fabricate a large-sized shape more than 600 × 600 × 600 mm. Because the MHC apparatus
employs a four-axis synchronized hotwire cutter with the structure of two XY movable heads and
a turn-table, it allows the easy fabrication of various 3D shapes, such as (1) an axisymmetric
shape or a sweeping cross-sectioned pillar shape using the hot-strip in the form of sweeping
surface and EPS foam block on the turn-table, (2) a polyhedral complex shape using the hotwire
and EPS foam block on the turn-table, and (3) a ruled surface approximated freeform shape using
the hotwire and EPS foam sheet. In order to examine the applicability of the developed MHC
apparatus, an axisymmetric shape, a polyhedral shape and a large-sized freeform shape were
fabricated by the apparatus.",,,,,,
"['Kobliska, John', 'Ostojic, Petar', 'Cheng, Xudong', 'Zhang, Xugang', 'Choi, Honseok', 'Yang, Yong', 'Li, Xiaochun']",2020-02-24T15:31:09Z,2020-02-24T15:31:09Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80083', 'http://dx.doi.org/10.26153/tsw/7104']",eng,2005 International Solid Freeform Fabrication Symposium,Open,thin film thermocouples,Rapid Fabrication of Smart Tooling with Embedded Sensors by Casting in Molds Made by Three Dimensional Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/12b6c17a-4401-425a-817c-20ac87a5317c/download,,"This paper is to investigate the feasibility of constructing “smart tooling” by embedding thin film
sensors, specifically, thin film thermocouples (TFTC) in castings made by molds formed by 3
Dimensional Printing (3DP). This study investigates whether thin film sensors can effectively be
cast into larger metal structures and if the sensors survive the casting process. The investigation
includes making 3DP molds to produce cast lap joint test bars of aluminum A356 and
electroplated nickel to characterize by mechanical testing to find the best process conditions to
maximize bond strength between the embedded thin film sensors and the cast material. Lastly
molds were made and embedded sensors were placed inside the mold for casting. Some of the
embedded sensors survived the casting process. In-situ monitoring of casting process with the
embedded sensors was accomplished.",,,,,,
"['Zhang, Wei', 'Leu, Ming C.', 'Ji, Zhiming', 'Yan, Yongnian']",2019-02-19T20:02:45Z,2019-02-19T20:02:45Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73441', 'http://dx.doi.org/10.26153/tsw/593']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'Rapid Prototyping']",Rapid Freezing Prototyping with Water,Conference paper,https://repositories.lib.utexas.edu//bitstreams/834813bb-4001-4413-b53b-bcf0e033dbe7/download,,"Rapid Freezing Prototyping (RFP) with water is a novel solid freeform fabrication technique that
can generate three-dimensional ice objects by depositing and rapidly freezing water layer by
layer. The support where necessary is made of brine whose. freezing point is lower than. pure
water. After building the part, the support can be removed by utilizing the melting temperature
difference between brine and water. Preliminary experiments have shown that the ice patterns
produced by this technique can be used for design visualization and silicone molding. This paper
will present the concept and some experimental results of the RFP process as well as potential
applications.",,,,,,
"['House, M. A.', 'Whitney, E. J.', 'Krantz, D. G.', 'Arcella, F. G.']",2018-11-14T16:55:49Z,2018-11-14T16:55:49Z,1996,Mechanical Engineering,doi:10.15781/T20Z71G7F,http://hdl.handle.net/2152/70240,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['titanium metals', 'Rapid prototyping', 'LaserCast']",Rapid Laser Forming of Titanium Near Shape Articles: LaserCast,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fec1a1f0-b938-4726-99f7-e17021bfc3fb/download,,"An ongoing collaborative program sponsored by the DoD Advanced Research Projects
Agency (DARPA) and the Office ofNaval Research (ONR) continues to show promising results in
the development of a new laser based manufacturing process. The program's goals are to develop
and demonstrate a laser based, rapid manufacturing system (LaserCastTM) for titanium and its
alloys. Economical precursor powders are being laser formed into integral, 100% dense, nearshape
articles by sequentially fusing multiple metal-powder layers in a controlled environment.
A CO2 continuous wave (CW) high energy laser has been used to form commercially pure (CP)
titanium, Ti-6AI-4V, and Ti-5AI-2.5Sn in varied geometries from I-inch square bars to a 4-inch
diameter (I-inch wall ) cylinder. Materials characterization tests, revealing excellent chemistry
control and mechanical properties, are presented. Large near-shape structures may be formed
directly from metal powders, without using molds or dies, by direct download and postprocessing
from a Computer Aided Design (CAD) database. Economic projections indicate
significant reductions in manufacturing costs and ""time to market"" production cycles when the
LaserCast process is used instead of conventional casting and forging processes.",,,,,,
"['Bingham, G. A.', 'Crookston, J . J.', 'Hague, R. J. M.', 'Long, A. C.']",2020-02-27T19:32:55Z,2020-02-27T19:32:55Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80095', 'http://dx.doi.org/10.26153/tsw/7116']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Rapid Manufactured Textiles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c22a25ff-46da-477a-b09d-ab3ede4b5ab0/download,,"Rapid Manufacturing (RM) is increasingly becoming a viable manufacturing process due
to dramatic advantages that are achievable in the area of design complexity. Through the
exploration of the design freedom, this paper introduces the concept of manufacturing textiles for
potential smart and high performance textile applications. This paper discusses the current
limitations associated with the manufacture of textiles through RM and presents a novel
methodology for the generation of 3D conformal RM textile articles. The paper concludes that
through RM it is entirely possible to manufacture a structure that incorporates drape and free
movement properties directly comparable to conventional textiles.",,,,,,
"['Frank, Matthew C.', 'Hunt, Christopher V.', 'Anderson, Donald D.', 'McKinley, Todd O.', 'Brown, Thomas D.']",2021-09-28T17:58:32Z,2021-09-28T17:58:32Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88138', 'http://dx.doi.org/10.26153/tsw/15079']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['rapid manufacturing', 'bone replacement', 'Subtractive Rapid Prototying']",Rapid Manufacturing in Biomedical Materials: Using Subtractive Rapid Prototyping for Bone Replacement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ae7db5b6-da94-4bd8-aeaa-3da918723930/download,University of Texas at Austin,"This paper presents methods for the rapid manufacturing of replacement bone fragments using a 
Subtractive Rapid Prototyping process called CNC-RP. The geometry of segmental defects in 
bone, resulting from traumatic injury or cancerous tumor resection, can be reverse-engineered 
working from medical images (such as CT scans), and then accurate defect fillers can be 
automatically generated in advanced synthetic biomaterials and other bioactive/biocompatible 
materials. The research provides evidence that suitable bone geometries can be created using 
subtractive RP from a variety of materials including Trabecular Metal® (porous tantalum), 
polymers, ceramics, and actual bone allografts. The research has implications in the orthopaedic 
treatment of segmental bone defects, as custom prototyped bone fillers should aid in bone growth 
and improve recovery.",,,,,,
"['Evans, R. S.', 'Bourell, D. L.', 'Beaman, J. J.', 'Campbell, M. I.']",2020-02-13T19:16:58Z,2020-02-13T19:16:58Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79963', 'http://dx.doi.org/10.26153/tsw/6988']",eng,2004 International Solid Freeform Fabrication Symposium,Open,rapid manufacturing,Rapid Manufacturing of Silicon Carbide Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/48af05fc-53dd-45c8-afb8-7b7220b776be/download,,"From the earliest days of SFF technology development, a viable technique for the direct
manufacture of fully-functional parts has been a major technology goal. While direct metal
methods have been demonstrated for a variety of metals including aluminum, steel and titanium,
they have not reached wide commercial application due to processing speed, final material
properties and surface finish. In this paper the development of an SLS-based rapid
manufacturing (RM) platform is reviewed. The core of this platform is a thermosetting binder
system for preform parts in contrast to the thermoplastic materials currently available for SLS.
The preforms may include metal and/or ceramic powders. A variety of fully functional parts
can be prepared from different combinations of materials and post processing steps including
binder pyrolysis, free-standing alloy infiltration, room temperature polymer infiltration and
machining. The main issues of these steps are reviewed followed by a discussion about the
support of RM. This paper is an intermediate report additional materials, applications, process
models and product design strategies will be incorporated into the project in the next year.",,,,,,
"['Hague, Richard', 'Dickens, Phill']",2019-12-05T16:59:44Z,2019-12-05T16:59:44Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78647', 'http://dx.doi.org/10.26153/tsw/5703']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Manufacturing,Rapid Manufacturing Research Group,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a64e1181-e572-4400-87b6-e5a29198249f/download,,"Rapid Product Development and manufacture is a major focus for companies
wanting to compete in the more open Global Marketplace. This has created
considerable interest in techniques and technologies that help companies introduce
new products more quickly, at lower cost and with greater flexibility. Computer Aided
Design (CAD) and the introduction, in the late 1980s, of a group of technologies
known as 'Rapid Prototyping' have greatly helped this. It is now possible to design
and manufacture objects within a few hours. The next stage is to use these layermanufacturing technologies to manufacture saleable end-use items. However, few
companies have invested in the technology, but many are very interested in
investigating their use. The research portfolio of the RMRG is directed at providing
the future technologies industry will require, and, through the Consortium, is
providing a route that allows partners, and others, to gain the required knowledge
and expertise concerning the technologies and their use.",,,,,,
"['Larsson, Morgan', 'Lindhe, Ulf', 'Harrysson, Ola']",2019-11-21T17:58:23Z,2019-11-21T17:58:23Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78547', 'http://dx.doi.org/10.26153/tsw/5603']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Rapid Manufacturing with Electron Beam Melting (EBM) - A Manufacturing Revolution?,Conference paper,https://repositories.lib.utexas.edu//bitstreams/95ae95bc-b9fe-4e88-abdf-156d5c478ff3/download,,"The Electron Beam Melting technology is the result of intensive research and
development and has a wide array of applications within areas such as Rapid
Prototyping, Rapid Manufacturing, Tooling and Biomedical Engineering. The
technology combines first-class material properties with high build speeds. The
presentation will provide a basic understanding of the technology, technical status,
applications and ongoing R&D.",,,,,,
"['Menon, Unny', 'Koch, Martin']",2018-04-16T17:21:20Z,2018-04-16T17:21:20Z,1991,Mechanical Engineering,doi:10.15781/T2DJ5904V,http://hdl.handle.net/2152/64310,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Industrial Engineering Department', 'Design and Manufacturing Processes', 'rapid prototyping']",Rapid Prototype for Foundry Tool Making: Curriculum and Industrial Projects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1eb99c52-5571-4590-b51f-41acd2572bff/download,,"This paper presents the evolution of an experimental .courseat Cal Poly which
applies rapid prototyping techniques, enabling a concurrent engineering approach
to product development. This is applied within our manufacturillgenvironmentof
foundry and machining processes. It focuses upon the.mainprobletnof rapid
tooling for these processes. A contemporary problenlprovided by industry is used
as the vehicle for illustrating rapidprototyping techniques within a concurrent
engineering context.",,,,,,
"['de Beer, D.J.', 'Barnard, L.J.', 'Booysen, G.J.']",2019-10-22T17:42:47Z,2019-10-22T17:42:47Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76324', 'http://dx.doi.org/10.26153/tsw/3413']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Visualisation,Rapid Prototyping (through SLS) as Visualisation Aids for Architectural Use,Conference paper,https://repositories.lib.utexas.edu//bitstreams/784e83b7-9665-4acc-aec9-19127f48e45e/download,,"The Cambridge International Dictionary of English, explains the word ""Design"" as a ""pattern
used to decorate something"". Whilst this very narrow-minded definition can spark a debate on the
meaning of design, it does however imply, that something has to made or manufactured,
following a process-chain which started with an idea, followed by the design, and finally, the new
product. As Functional Design is closely linked to inter alia manufacturing and building,
Designers' freedom to express themselves, are often limited by the capabilities of craftsmen who
have to give physical substance to Designer's ideas.
The recently completed Manufacturing and Materials national FORESIGHT report [1] from the
Department of Arts, Culture, Science and Technology (DACST) of the South African
Government shows that manufacturers wishing to compete internationally should focus on
integrated product, process and production system design, to speed up production time. This is all
encapsulated in Concurrent Engineering, where design and approval are configured into a
parallel, iterative process. Whilst it is not only dependent of technologies, technology and
enabling tools such as Rapid Prototyping, applied in an integrated process, are crucial in the
successful application of Concurrent Engineering. In the past a series of technologies, e.g. CAD,
CAM and NC manufacturing was identified to solve these problems. Rapid Prototyping, Solid
Freeform Fabrication or Generative Manufacturing - which are all synonyms for new methods of
building physical parts directly from CAD data - represent the latest trends in manufacturing
technology.
However, all these techniques represent only a technological view on how product development
can meet the tremendous challenges of the future. In fact, not merely the use of a single
technology provides better products faster for the market, but the integration of a large number
of technologies and methodologies. Therefore, aspects of information processing, cost, quality
and time management, team work, organisational issues and many other enabling technologies
like data highways, multi-media or distributed databases have to be taken into account as well.
Rapid Prototyping is being used more and more as a key enabling technology in reducing the time
to market for new products, by identifying possible design flaws prior to tooling and
manufacturing, and is providing the common focus for multidisciplinary groups, around which
to resolve design and development questions. Barkan and Iansti present RP as a means of rapid
learning at every stage of the design process. Adopting this view on the whole of the
development process, one comes to the conclusion that the use of RP to enable Rapid Product
Development, is a fundamental challenge that must be addressed by all manufacturers to remain
competitive in today's global market place.
35
In defining manufacturing, one tends to think about plastic products, casting, tooling concerned,
and mass production. Whilst this represents the latest trends in manufacturing, one of the oldest
methods of manufacturing however, is the conversion of basic raw materials into
accommodation, shelters, etc. In adopting Rapid Prototyping and related technologies into the
built and architecture environment, numerous new opportunities open up. The paper describes a
fresh approach into an age-old industry.",,,,,,
"['Chiang, J.', 'Lehmicke, M.', 'Dcosta, D.', 'Xu, X.', 'Lin, F.', 'Sun, W.']",2019-10-18T16:50:47Z,2019-10-18T16:50:47Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76258', 'http://dx.doi.org/10.26153/tsw/3347']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Assisted,Rapid Prototyping Assisted Design and Development of Inter-Vertebral Implants,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3ed627e-44d7-47a7-bae5-4cddbc70561c/download,,"This paper presents a case study of applying rapid prototyping in assisting in the design and
development of inter-vertebral implants for spine fusions. The major process of design and
implant development, its biological and mechanical requirements, the approach for developing a
3D reconstructive vertebral anatomy model, the inter-vertebral implant CAD model, and the
integration with a finite element analysis for the implant's structural analysis are presented. The
process of 3D Printing of the vertebral anatomy and the inter-vertebral implant is described. The
application of the prototyping model in assisting in the inter-vertebral anatomic fitting, in
guiding the implant's geometric design, in helping with the virtual surgical planning, and in
understanding the implant's mechanical properties and structural stability are discussed.",,,,,,
"['Roberts, Floyd', 'Lomshek, David', 'Brower, William E.']",2018-04-19T18:20:58Z,2018-04-19T18:20:58Z,1992,Mechanical Engineering,doi:10.15781/T2MK65R8K,http://hdl.handle.net/2152/64404,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['CAD designs', 'rapid prototyping', 'in-flight rapid prototyping']",Rapid Prototyping at Zero Gravity for In-Flight Repairs and Fabrication on Space Station Freedom,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b78be0b8-883a-4810-876d-238f11e34a30/download,,"The ability to perform in-flight rapid prototyping would be of great benefit to NASA in two ways.
First, repair parts could be fabricated from CAD designs beamed up from earth based laboratories which
might allow a failed experiment to proceed. The mission specialists themselves, under the creative
influence of space flight, might design a new part or tool and fabricate it on board in a matter of hours.
Second, with metal casting and ceramic sintering facilities on board, rapid prototyping would allow
manufacturing in space. This paper presents some test criteria for evaluating two of the rapid prototyping
techniques, stereolithography and fused deposition, in microgravity conditions. Effects of the variation
of head speed and strip width for the fused deposition process on the resulting mechanical properties are
presented. The mechanical strength of the polyamide test bars increased with both increasing head speed
and strip width. Increasing head speed would be desirable in microgravity applications.",,,,,,
"['Wang, Jianguo', 'Wong, Y.S.', 'Fuh, Jerry', 'Loh, H.T.', 'Du, ZhaoHui', 'Hong, GuoDong', 'Yan, YongNian']",2019-02-19T20:17:49Z,2019-02-19T20:17:49Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73444', 'http://dx.doi.org/10.26153/tsw/596']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'CMM']",Rapid Prototyping Based on 2D Photographic Images,Conference paper,https://repositories.lib.utexas.edu//bitstreams/525e0d9f-51ca-4697-a78b-1916445165cf/download,,"Generally it is difficult to get a 3D model from its 2D images. However, if the object is
symmetric and its photograph is taken in appropriate perspective, then it is possible to extract
pertinent 3D information from its 2D images. In this paper, a reverse engineering method to
derive the 3D surface model from 2D photographs is introduced. Through a case study, the entire
process from photo taking to 3D model making and subsequent rapid prototyping of a model car
is introduced. The techniques and related problems of reverse engineering and rapid prototyping
are discussed and the future research direction is proposed.",,,,,,
"['Jones, K. G.', 'Campbell, R. I.']",2018-12-06T21:57:43Z,2018-12-06T21:57:43Z,1997,Mechanical Engineering,doi:10.15781/T2P55F32K,http://hdl.handle.net/2152/71433,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'RPDSS']",Rapid Prototyping Decision Support System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a1b859ac-2138-4f30-b461-dffbda93aded/download,,"An application has been produced to rate Rapid Prototyping system suitability based on designer
requirements. The software is part of a project to produce a comprehensive Design For Rapid
Prototyping (DFRP) methodology. Using a combination of database searches and user-defined
weighted. rating, the system uses various design requirements to make qualitative suitability
decisions. MS Visual Basic has been used to implement a user-interface to manipulate an MS
Access database. Proposed features include system validation achieved by designers' feedback on
prototype performance. This will help to remove the false expectations sometimes associated with
RP and will ultimately promote its wider usage.",,,,,,
"['Prasad, K. Siva', 'Rathakrishnan, E.', 'Dhande, Sanjay G.']",2019-11-21T17:42:41Z,2019-11-21T17:42:41Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78541', 'http://dx.doi.org/10.26153/tsw/5597']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Aerospace,Rapid Prototyping for Aerospace Launch Vehicles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aca7045b-a747-409e-8ad2-72aab062a210/download,,"Initial studies of the aerodynamic characteristics of proposed launch vehicles can be made more
accurately if lower cost, high-fidelity aerodynamic models are available for wind tunnel testing
early in design phase. Rapid Prototyping (RP) is an emerging key technology for producing
accurate parts directly from CAD models quickly, with little need of human intervention. Use of
RP models was studied at the NASA Marshall Space Flight Center (MSFC). It was concluded
that RP methods and materials can be used only for preliminary design studies and limited
configurations because of the RP material properties that allow bending of models under higher
loading conditions. The reported results and analysis were based on wind tunnel balances. These
balances give total load on the body. Thus, there is a need for studying the pressure distribution,
the wave pattern and the system behavior under high-speed conditions. In order to study the
above goals, a blunt nose cone of a launch vehicle/ missile was tested which was made using the
solid based RP method FDM, with a Mach number of 2.0. It is concluded that RP models can
take the load at the Mach number 2.0 and also can capture the pressure distribution and wave
pattern.",,,,,,
"['Geng, L.', 'Wong, Y.S.', 'Hutmacher, D.W.', 'Feng, W.', 'Loh, H.T.', 'Fuh, J.Y.H.']",2019-11-21T17:56:34Z,2019-11-21T17:56:34Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78546', 'http://dx.doi.org/10.26153/tsw/5602']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Scaffolds,Rapid Prototyping of 3D Scaffolds for Tissue Engineering Using a Four-Axis Multiple-Dispenser Robotic System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a243bff-bc47-4656-ba0d-f87b3db1894e/download,,"A desktop rapid prototyping (RP) system has been developed to fabricate scaffolds for tissue
engineering (TE) applications. The system is a computer-controlled four-axis machine with a
multiple-dispenser head. This paper presents the scaffold fabrication process to build free-form
scaffolds from relevant features extracted from given CT-scan images for TE applications. This
involves obtaining the required geometric data for the scaffold in the form of a solid model from
CT-scan images. The extracted scaffold model is then sliced into consecutive two-dimensional
(2D) layers to generate appropriately formatted data for the desktop RP system to fabricate the
scaffolds. The basic material processing involves the sequential dispensing of two or more
materials to form a strand. The four-axis system enables strands to be laid in a different direction
at each layer to form suitable interlacing 3D free-form scaffold structures. The multipledispenser head also allows the introduction of living cells and additional materials during the
scaffold building. The building of the scaffolds with the desktop RP system is described based on
the sequential dispensing of chitosan dissolved in acetic acid and sodium hydroxide solution.
Neutralization of the acetic acid by the sodium hydroxide results in a precipitate to form a gellike chitosan strand.",,,,,,
"['Kumar, Ranjeet', 'Kapil, Sajan', 'Negi, Seema', 'Gehlot, Nihal', 'Gopalakrishna, Suhas Hurli', 'Karunakaran, K.P.']",2021-11-04T18:05:31Z,2021-11-04T18:05:31Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89991', 'http://dx.doi.org/10.26153/16912']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['rapid prototying', 'expanded polystyrene', 'evaporative pattern casting']",Rapid Prototyping of EPS Pattern for Complicated Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9c33481-6a14-414d-aa88-2c3868e1a4f9/download,University of Texas at Austin,"In Rapid Prototyping (RP) process the 3D object is approximated into several 2D slices. All
these slices are of a uniform thickness hence called uniform slicing of zeroth order
approximation. Such a system always suffers with the staircase defects. Very thin slices have to
be used to minimize these defects, which increase the production time. In this work, a RP system
called Segmented Object Manufacturing (SOM) is used to produce the Expanded Polystyrene
(EPS) pattern, which uses adaptive slicing with higher order approximation. This system uses the
concept of visible slicing in which a complicated object is produced by converting it into the
accessible (visible) segments. This is a hybrid system for producing EPS patterns which utilizes
the advantages from subtractive and additive processes. These EPS patterns found their
application in Evaporative Pattern Casting (EPC). EPS bracket is produced by SOM machine to
prove the capability of the system.",,,,,,
"['Nakagawa, Takeo', 'Noguchi, Hiroyuki']",2018-11-09T16:34:16Z,2018-11-09T16:34:16Z,1996,Mechanical Engineering,doi:10.15781/T2P844F9C,http://hdl.handle.net/2152/69933,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'R/P model', 'forming process']",Rapid Prototyping of Fine Ceramics: Slurry Casting Using Silicon Rubber Mold,Conference paper,https://repositories.lib.utexas.edu//bitstreams/20ad7367-cde2-4f19-9bdb-7f019e80b389/download,,,,,,,,
"['Kupp, Donald', 'Eifert, Harald', 'Greul, Matthias', 'Kunstner, Matthias']",2018-11-29T20:54:29Z,2018-11-29T20:54:29Z,1997,Mechanical Engineering,doi:10.15781/T2VH5D39J,http://hdl.handle.net/2152/70343,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['3D CAD', 'rapid prototyping.']",Rapid Prototyping of Functional Metal and Ceramic Components By The Multiphase Jet Solidification (MJS) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/636c4298-e40b-414d-ab6f-da0bdb5da6f3/download,,"The need to generate high-quality conceptual models ofmanufacturing
components and limited application functional components has driven the development
ofRapid Prototyping (RP) in the last fifteen years. Recently, however, it has become
increasingly obvious that an RP system that can produce fully functional components in
materials other than polymers would be beneficial. In order to fulfill the requirements for
the direct production ofmetallic and ceramic components for functional testing and
application, the development ofnew processes and materials are key development areas
at the Fraunhofer Institute for Applied Materials Research (IFAM) and the Fraunhofer
Resource Center-Delaware (FRC-DE). For the free-form fabrication of ceramic and
metal parts, the Multiphase Jet Solidification (MJS) process has been developed for
producing metal and ceramic components. The MJS process extrudes metal and ceramic
based binder systems (such as A120 3, SiC, stainless steel, and Ti), forming the desired
component layer by layer. As in powder injection molding, after a part is formed by
MJS, the binder phase is removed chemically or thermally and the remaining powder
compact is sintered to final density. This paper presents the MJS technique and outlines a
variety ofpotential applications.",,,,,,
"['Maxwell, J.', 'Larsson, K.', 'Boman, M.']",2019-02-26T18:01:39Z,2019-02-26T18:01:39Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73492', 'http://dx.doi.org/10.26153/tsw/642']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['laser chemical vapor deposition', 'primary fabrication tool']",Rapid Prototyping of Functional Three-Dimensional Microsolenoids and Electromagnets by High-Pressure Laser Chemical Vapor Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/732d3647-e62e-4985-ad53-983c4b082a4c/download,,"Three-dimensional laser chemical vapor deposition (3D-LCVD) is an emerging process
which bridges the gap between various macro-scale rapid prototyping (RP) systems and microfabrication technologies. With the ability to deposit both metals and dielectrics 3D-LCVD
may be used to prototype integrated electromechanical components from sub-micron to centimeter scales. This technological niche is increasingly important with the ever-decreasing size
and sophistication of consumer and industrial products.
The objective of this work was the development of functional microsolenoids and electromagnets, using 3D-LCVD as the primary fabrication tool. High-aspect-ratio microsolenoids
have the potential to generate much greater magnetic-field densities than their thin-film counterparts,l and have many advantages when used as actuators in microelectromechanical systems (MEMS).2 3D-LCVD provides a means of fabricating such helical structures, with an
ease unparalleled by any lithographic or rapid prototyping process.",,,,,,
"['Wohlert, Martin', 'Bourell, David']",2018-11-09T15:14:43Z,2018-11-09T15:14:43Z,1996,Mechanical Engineering,doi:10.15781/T2V11W54G,http://hdl.handle.net/2152/69924,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['RP Process', 'SLS', 'polymer debinding']",Rapid Prototyping of Mg/SiC Composites by a Combined SLS and Pressureless Infiltration Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b1adb24-433f-4e80-88b2-c1b18a9dcf4f/download,,"The expanding market for metal matrix composites (MMCs) presents a unique niche application for
rapid prototyping I manufacturing. MMCs are well suited to RP for two reasons. First, these
relatively new high performance materials are largely used in high cost, low production
applications which are easily accommodated by RP techniques. Second, the hard and brittle
ceramic reinforcement phases used in MMCs add cost and complexity to traditional production
methods. Special tools or processes are required to machine these materials, and the cost and
design limitations imposed by the production of a mold limit the competitiveness of casting [1,2].
In comparison, the additive nature of Selective Laser Sintering (SLS) avoids the problems
associated with machining of the ceramic phase, and the wide range of geometries which can be
produced ensures the versatility of the process.",,,,,,
"['Lyons, Brett', 'Batalov, Marat', 'Mohanty, Pranavasu', 'Das, Suman']",2020-02-24T15:20:40Z,2020-02-24T15:20:40Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80081', 'http://dx.doi.org/10.26153/tsw/7102']",other,2005 International Solid Freeform Fabrication Symposium,Open,proton exchange membrane fuel cells,Rapid Prototyping of PEM Fuel Cell Bi-Polar Plates using 3D Printing and Thermal Spray Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f67847a2-f2a9-4593-a920-60d246f3425a/download,,"This article presents the results of exploratory research on novel methods for the
fabrication of functional, metallic, gas flow, bi polar plates (BPP) for use in proton
exchange membrane fuel cells (PEMFC). Low cost, high speed, additive manufacturing
methods that combine 3D printing (3DP) and thermal spray (TS) technologies are
described. Functional flow plates were manufactured by creating 3DP patterns and then
depositing, and releasing, dense metals with TS methods. The new method yields dense
metal plates, with interesting options for material choices and complex designs.",,,,,,
"['Maxwell, James', 'Shah, Jubin', 'Webster, Terry', 'Mock, Jason']",2019-02-26T20:24:28Z,2019-02-26T20:24:28Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73498', 'http://dx.doi.org/10.26153/tsw/648']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['3D-LCVD', 'alloys']",Rapid Prototyping of Titanium Nitride Using Three-Dimensional Laser Chemical Vapor Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d114032-a20b-4cf8-9206-9fd132852f05/download,,"Selective vapor deposition o/titanium nitride was realizedfrom titanium tetrakis-dimethylamide, Ti(N(CH3)2)4, at pressures up to 138 mbar. High-aspect-ratio needles up
to mm long were grown at axial rates up to 10 pm/so The morphology and composition o/thefibers will be described. The temperature rise during transient growth was
apparent in the grain size o/the resulting needles. Severe mass-transport limitations
were also observed due to the multiplicity o/precursor by-products. A primary application o/this workwill be the rapidprototyping o/highly-elastic, lightweightstructural
elements and matrices.",,,,,,
"['Ribeiro, A. F.', 'Norrish, John']",2018-11-14T17:04:20Z,2018-11-14T17:04:20Z,1996,Mechanical Engineering,doi:10.15781/T2W95174M,http://hdl.handle.net/2152/70241,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'CAD', '3D solid component']",Rapid Prototyping Process Using Metal Directly,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a26c447c-8527-4aee-a9a6-630ee0355a5b/download,,"Rapid Prototyping emerged in the USA in the late 80's and it made the whole industry rethink
their way of making prototypes. Several new different process have emerged since then and these
vary in materials, times, prices, fInishing quality, etc. However, not many have achieved acceptable
results with using 100% pure metal. Some heavy industry want prototypes made with metal in order
to assess not only the shape of the prototype but also its hardness conditions and functionality of the
component in real situations. This technique is still under development at several different places and
although some research have been done recently the results are not yet as desired.
In the last couple of years a Rapid Prototyping process involving direct deposition of metal had
been under development (as a PhD research) at Cranfield University. The process entails the use of a
Gas Metal Arc fusion welding robot which deposits successive layers of metal in such way that it
forms a 3D solid component.
A solid model is frrst drawn using a CAD system, then data indicating the kind of layers and
dimension is incorporated and the solid is automatically sliced. This slicing routine also generates
reports on the welding time and conditions for the production of the component and automatically
generates the robot program.
Depending on the complexity of the component, the time from drawing the component to being
ready to press the robot start button to make the component can take less than a couple of hours.
Several test components were produced with good characteristics and perfectly acceptable
surface finishing. This paper describes the process and shows some samples.",,,,,,
"['Dickens, P.M', 'Pridham, M.S', 'Cobb, R.C.', 'Gibson, I.', 'Dixon, G.']",2018-04-19T18:34:48Z,2018-04-19T18:34:48Z,1992,Mechanical Engineering,doi:10.15781/T2ZW1990V,http://hdl.handle.net/2152/64409,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['3-D Welding', 'rapid prototyping', 'Department of Manufacturing Engineering and Operations Management', 'Laminated Object Manufacturing']",Rapid Prototyping Using 3-D Welding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3651875-456d-4d29-ade4-ecf5d30c5c96/download,,"Rapid prototyping systems are based, almost exclusively on polymer, or paper materials.
The dimensions of the parts produced are limited by the volume of the processing area within
the machine, and parts tend to warp or distort due to shrinkage and lack of support. Also the
mechanical properties of the part are restricted to those of the processable materials and thus,
in many cases, required 'engineering properties' cannot be obtained",,,,,,
"['Dover, S J', 'Rennie, A E W', 'Bennett, G R']",2018-11-09T16:47:49Z,2018-11-09T16:47:49Z,1996,Mechanical Engineering,doi:10.15781/T2902018X,http://hdl.handle.net/2152/69936,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['EDM', 'electrolyte', 'SFF']",Rapid Prototyping using Electrodeposition of Copper,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8acf1be1-2f24-4d93-9609-2447582d1091/download,,"Injection mould cavities and EDM electrodes were produced from High Speed Selective
Jet Electrodeposition (HSSJE). The performance ofthe electrodes in the EDM process and the
surface finish ofthe tools produced were studied. Studies were made into optimising the HSSJE
build process",,,,,,
Walters,2018-04-19T18:38:04Z,2018-04-19T18:38:04Z,1992,Mechanical Engineering,doi:10.15781/T2KK94W0X,http://hdl.handle.net/2152/64412,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'Fused Deposition Modeling', 'manufacturing process']","Rapid Prototyping Using FDM: A Fast, Precise, Safe Technology",Conference paper,https://repositories.lib.utexas.edu//bitstreams/bcfe1fe5-0910-4533-b96e-16b172f73790/download,,"This paper outlines the use of
FDM to speed product design and
to streamline the manufacturing
process.
Time compression, the ability to
quickly reduce the time it takes to
get new products to market, has
increased the pressure on all phases
of the manufacturing process.
Manufacturers must find and
implement time saving systems
without sacrificing quality.",,,,,,
"['Soo, S.C.', 'Yu, K.M.']",2019-10-18T16:06:39Z,2019-10-18T16:06:39Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76247', 'http://dx.doi.org/10.26153/tsw/3336']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fractal,Rapid Prototyping using Fractal Geometry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b3bc42a-1911-469e-9b29-df8497e6203d/download,,"The paper proposes a method for rapid prototyping (RP) fractal geometry represented
objects. RP technology has made possible the physical fabrication of solid freeform objects.
However, contemporary CAD/CAM/RP systems are developed for Euclidean geometry and are
incapable of handling self-similar fractal objects (e.g. jewelry products). To address the problem,
a Radial-Annular Tree (RAT) data structure is proposed to represent Iterated Function Systems
(IFS) fractal curves. RP toolpaths can then be generated from the RAT data structure. Geometry
modeled in the RAT data structure can also be combined with Euclidean geometry from
traditional CAD systems to make aesthetic patterns for the jewelry industry.",,,,,,
"['Campbell, R.I.', 'Dickens, P.M.']",2018-09-27T19:24:07Z,2018-09-27T19:24:07Z,1994,Mechanical Engineering,doi:10.15781/T2M03ZG6J,http://hdl.handle.net/2152/68606,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['fastest developing manufacturing technologies', 'CAD', 'Photo polymerisation process development']",Rapid Prototyping: A Global View,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a103ff6c-435b-479e-afb5-9ec90d50b64f/download,,"Rapid prototyping technology is advancing at a tremendous rate. Much of this
progress is due to research being conducted within academic institutions and industry
throughout the world. The USA is leading the research community in this field but a
significant contribution is coming from Europe, Japan and elsewhere. The primary aim of
this paper is to give a worldwide overview of current research activity and initiatives.
Hopefully, this will enable researchers to see where their own work fits into the global
picture. If this leads to increased co-operation and a reduction in duplication of effort,
then an even faster rate of advance should be attainable.",,,,,,
"['Weaver, Timothy J.', 'Thomas, Julian A.', 'Atre, Sundar V.', 'German, Randall M.']",2019-02-26T16:41:09Z,2019-02-26T16:41:09Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73484', 'http://dx.doi.org/10.26153/tsw/634']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'mechanical properties']",Rapid Steel Tooling Via Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/20643f19-204d-4b07-ad89-8f898b5b5297/download,,"With increasing part complexity and requirements for long production runs, tooling has
become an expensive process that requires long lead times to manufacture. This lengthens the
amount oftime from ""art to part"". Rapid tooling via stereolithography (SLA), filled epoxies, etc.
have been stopgap measures to produce limited prototyping runs from (10 to 500 parts). This
gives poor dimensional analysis and does not allow for limited production runs of 1000+ parts.
The method ofproducing prototype tooling with a powdered metal process has been developed
that produces tooling with a hardness greater than 35 HRC and total shrinkage less than 0.5%.
This tooling process manufactures production ready tooling that will perform extended cycle
runs (100,000+). Manufacturing ofthis tooling takes 1 to 2 weeks and will compare favorably
with production grade steel tooling. Originals drawn in 3D CAD can be used to prototype the
master that will allow for the production ofthe rapid metal tool set.
process starts with a rapid prototyped model made by whatever process is desired or
a machined master. For this paper a Sander's Model Maker II® rapid prototyping machine was
used to fabricate the model. After the model ofthe tool set is made, a silicone rubber negative is
cast around that model. After the silicone rubber model is made, a heated slurry ofmetal
powders and polymers is poured into the mold to create the green tool set. The tool set is left to
cool, and then removed from the silicone rubber mold. The tool set is then debound and sintered
to produce a final tool set with properties approaching hardened tool steel.",,,,,,
"['NOGUCHI, Hiroyuki', 'NAKAGAWA, Takeo']",2018-11-30T16:27:38Z,2018-11-30T16:27:38Z,1997,Mechanical Engineering,doi:10.15781/T2KP7VB4N,http://hdl.handle.net/2152/70596,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SLS']",Rapid Tooling by Powder Casting Transferred from RIP Model -Manufacturing Conditions Pursuing Zero Shrinkage,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6646ec7e-fb28-43d3-b4f8-46eafd8ab755/download,,"High accuracy is being sought in the rapid manufacturing of long life metal
dies and molds by transferring from layer laminated models. Powder casting serves
as a promising rapid tooling method as it enables high density filling and thus
controls dimensional shrinkage to a considerable extent during sintering and
infutrating This study aims to study the relation between the tooling conditions
and dimensional changes of powder casting and fmd the conditions at which
dimensional changes are minimum. In the experiments performed, a golf ball
model was chosen as an exampIe of a small mold and results show that dimensional
changes can be controlled to below 0.1%, which will facilitate practical application.
By subjecting the cast powder to vibrations after adding the binder to achieve
higher density, and adding fme copper powder to a mixture of two different size
stainless steel powders for dimensional adjustments, almost zero shrinkage control
in rapid tool making was realized.",,,,,,
"['Stucker, Brent', 'Malhotra, Muni', 'Qu, Xiuzhu', 'Hardro, Peter', 'Mohanty, Natalie']",2019-09-23T15:14:04Z,2019-09-23T15:14:04Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75931', 'http://dx.doi.org/10.26153/tsw/3030']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Accuracy,RapidSteel Part Accuracy 133,Conference paper,https://repositories.lib.utexas.edu//bitstreams/af566322-8e8c-4c28-aa7f-38d4a85e014b/download,,,,"In order to assess the effect of various furnace processing parameters on RapidSteel part accuracy, a series of experiments were performed on linear dimensional changes during processing of RapidSteel 2.0 and LaserForm ST-100. An understanding of these dimensional changes is critical for building parts and tools which are capable of being used in high tolerance applications and for finish machining of near-net shapes to high tolerances. A unique part was designed for this study and is shown as Figure 1. This part has both internal and external measurable dimensions in the x, y and z axes. The smallest dimension in each
direction is 0.3 inches and the largest dimension is 3.0 inches. This provides an order of magnitude difference between the smallest and largest dimensions.RapidSteel 2.0 (RS2) is a commercially available metal material from DTM Corporation. It is made by Selective Laser Sintering of stainless steel 316 powders with polymer binders followed by a binder burnout and sintering furnace run, and a second infiltration furnace run where a 90% Cu, 10% Sn bronze is infiltrated into the porous stainless steel structure. LaserForm ST-100 (ST-100) is the latest version of RapidSteel and is a stainless steel 420 material that is sintered and infiltrated in one furnace run. The significant difference between RS2 and ST-100 is that the ST-100 has a broader particle size range, with fine particles not being screened out. These fine particles allow the ST-100 material to be sintered at a lower temperature than the RS2 powder, which makes possible the single furnace run for sintering and infiltration. Benefits of ST-100 include that it is a magnetic material and can be fixtured using magnetic chucks and that the finer particles allow for greater feature definition, sharpness of corners and strength of green parts.",,,,
"['Deppe, Gereon', 'Kaesberg, Martin', 'Koch, Rainer']",2021-11-08T22:30:30Z,2021-11-08T22:30:30Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90057', 'http://dx.doi.org/10.26153/tsw/16978']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'decision support', 'aerospace', 'spare parts', 'MADM', 'multi attribute decision making']",Rational Decision-Making for the Beneficial Application of Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/54662f10-6627-4f34-b180-9ae934814a73/download,University of Texas at Austin,"Additive Manufacturing is a technology that offers a high potential for industrial
companies. Nevertheless, companies lack experience with this new technology and face the
problem to identify processes where a successful and beneficial application can be achieved. They
have to be supported in this analysis with a decision support tool which is capable to compare
different manufacturing or repair approaches in order to determine the optimal solution for the
correspondent use case. This is not always driven solely by costs but can also be critically affected
by further influencing factors. This is why the decision support takes into account also time and
quality alongside the costs. For a time-critical spare part supply, for example within aerospace
sector, they are substantial for taking a decision. The presented decision support features a multi-attribute decision-making approach for selecting the most appropriate process, either Additive
Manufacturing, conventional technologies or an external procurement.",,,,,,
"['Evans, R. Scott', 'Bourell, David L.', 'Beaman, Joseph J.', 'Campbell, Matthew I.']",2019-11-21T17:54:14Z,2019-11-21T17:54:14Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78545', 'http://dx.doi.org/10.26153/tsw/5601']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Silicon Carbide,"Reaction Bonded Silicon Carbide: SFF, Process Refinement and Applications",Conference paper,https://repositories.lib.utexas.edu//bitstreams/325431df-8772-436e-8c9d-186f8a41b3db/download,,"Reaction bonded silicon carbide (RBSiC) has a wide variety of industrial applications and
a manufacturing process based on Selective Laser Sintering (SLS) has been demonstrated in
previous research at the University of Texas. That study was directed toward semiconductor
manufacturing applications and was based on prior indirect SLS methods. Several key research
questions were addressed for three main manufacturing phases: preform SLS, binder burnout and
reactive infiltration. The current research is focused on development of material systems and
manufacturing capability and is directed toward a broader set of potential applications. Preform
formation utilizes SiC powder of an appropriate average particle size mixed with a multicomponent binder. The preform or green part is then placed in a vacuum furnace to carbonize
the binder. The details of the binder chemistry must support accurate SFF shapes and acceptable
surface roughness, a strong green part and maintenance of the part shape during the first furnace
operation. Finally, the physics and chemistry of the infiltration process, based on the
microstructure of the initial green preform, determine the viability of the manufacturing process
and the characteristics of the final composite material.
The functionality of metal, polymer and ceramic matrix composites can support the
growing SFF industry desire to move beyond functional prototyping and into manufacturing
arenas. This project is being explored for more general application to matrix composite
materials, especially highly functional systems tailored specifically for SLS. The goal is to
establish the governing principles of binder function, carbonization and infiltration as well as to
understand the interdependence of these phases in terms of manufacturing application. With this
understanding new applications and special SLS composites can support the development of new
products and a greater SFF manufacturing presence.
This paper provides an introduction to the material, a look at basic rapid manufacturing
trends, an overview of the previous work, a review of relevant RBSiC material science issues,
and an outline of the current study.",,,,,,
"['NARAHARA, Hiroyuki', 'TANAKA, Fumiki', 'KISHINAMI, Takeshi', 'IGARASHI, Satoru', 'SAITO, Katsumasa']",2018-12-07T17:18:55Z,2018-12-07T17:18:55Z,1997,Mechanical Engineering,doi:10.15781/T2ZG6GT3V,http://hdl.handle.net/2152/71454,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['UV-laser beam', 'removal processing']",Reaction Heat Effect On Initial Linear Shrinkage of Sterelothigraphy Resins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d333d08-cf18-42ae-b4af-86a53349b3b5/download,,"In the industrial use ofthe Stereolithography, the precision is always a problem. Basic
phenomenon of the solidification shrink has not suffiCiently investigated This study aims at
clarifying the initial linear shrinkage ofcured resin in a minute volume. Experimental equipment
has been developed which measures the time history of the single strand in situ in a
stereolithography machine. Analysis model about the time history of a minute volume linear
shrinkage has been shown using with the measured shrinkage of a cured line segment. The
relation between the time history ofthe linear shrinkage and the temperature was measured and
the shrinkage in the minute volume after irradiation has been caused by the temperature
variation",,,,,,
"['Foerster, A.', 'Wildman, R.', 'Hague, R.', 'Tuck, C.']",2021-11-04T15:11:17Z,2021-11-04T15:11:17Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89983', 'http://dx.doi.org/10.26153/tsw/16904']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['reactive inkjet printing', '3D silicone structures', 'elastomeric structures']",Reactive Inkjet Printing Approach Towards 3D Silicone Elastomeric Structures Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f9132463-8efb-48a6-a61e-e607cd5ad0a3/download,University of Texas at Austin,"Production of 3D silicone structures with tailored architectures has a wide number of
applications including soft robotics and stretchable electronics. This work investigates a
method based on a reactive inkjet printing approach to produce 3D silicone structures. Printing
parameters including pressure and temperature for jetting SE1700 ink to produce silicone
structures were optimised. Additives, silicone oil and vinyl terminated polydimethylsiloxane
were added to the main SE1700 formula to evaluate mechanical properties of the final parts.
Characterisation was performed to understand the change in a sample’s properties in relation
to different formulations. Silicone structures with different porosities were printed and the
mechanical properties were investigated. It has been demonstrated that 3D silicone structures
can be produced using reactive inkjet printing approach. The presented method allowed
tailoring of the mechanical properties of silicones without increasing the viscosity properties
of the base material by adjusting the silicone formula and using different structures.",,,,,,
"['Zhao, Changxuan', 'Jariwala, Amit S.', 'Rosen, David W.']",2021-10-28T15:17:24Z,2021-10-28T15:17:24Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89661,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['photopoymerization', 'scanning points', 'real-time monitoring', 'exposure controlled projection lithography']",Real Time Monitoring of Exposure Controlled Projection Lithography with Time-Varying Scanning Points,Conference paper,https://repositories.lib.utexas.edu//bitstreams/46f26d68-cee5-45bb-bc15-5a0172f1793b/download,University of Texas at Austin,"Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in
which photopolymer resin is used to fabricate lens shaped features. During this process, a dynamic
mask projects radiation patterns through a transparent substrate onto the photopolymer resin to
grow features from the substrate surface. We present a novel method to monitor the
photopolymerization process in real-time with higher spatial resolution in a plane perpendicular to
the polymerization growth. A Spatial Light Modulator (SLM) was incorporated into our
Interferometric Cure Monitoring (ICM) system, which periodically moves the positions of the
scanning points onto the curing area to estimate the cured part height. This time-varying scanning
strategy avoids interference caused by points too close to one another and enables higher spatial
resolution than fixed scan patterns. This time-varying multi-point monitoring approach is
experimentally validated to measure the cured part height and the lateral dimensions of the cured
part at the substrate level.",,,,,,
"['Bossett, Evan', 'Rivera, Lorna', 'Qiu, Dan', 'McCuiston, Ryan', 'Langrana, Noshir', 'Rangarajan, Shriram', 'Venkataraman, Natesan', 'Danforth, Stephen', 'Safari, Ahmad']",2019-02-19T17:46:41Z,2019-02-19T17:46:41Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73434', 'http://dx.doi.org/10.26153/tsw/586']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'deposition']",Real Time Video Microscopy for the Fused Deposition Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5ecc52b-aa43-42fb-8cd6-41083c0503de/download,,"Fused deposition is a layered manufacturing technology, which is being investigated for
fabrication of functional parts. Defects and voids in the build process affect the quality andlevel
of accuracy of components. These occur due to several factors, such as the.toolpath contours in a
layer, material(s) deposited, and the environmental/conditions. For a functional part to be
constructed, a perfect green part is critical. To further understand this process, a visualization of
the deposition is needed. Therefore, we have developed a real-time. video microscopy system.
The hardware has been constructed and mounted on theexistingliquifier.·Real time deposition·of
layered manufacturing is being recorded. Three materials being investigated are: PZT, silicon
nitride, and wax. The contrast in wax layering is not as strong, which·makes•• visual observation
extremely hard. However, interaction between the roads of PZT and silicone nitride parts has
been successfully quantified. Using the current set. up and software, the raod width and height
have been quantified.",,,,,,
"['Liu, Chenang', 'Wang, Rongxuan', 'Kong, Zhenyu', 'Babu, Suresh', 'Joslin, Chase', 'Ferguson, James']",2021-11-16T16:20:33Z,2021-11-16T16:20:33Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90332', 'http://dx.doi.org/10.26153/tsw/17253']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'surface morphology', 'real-time measurement', 'deep learning']",Real-Time 3D Surface Measurement in Additive Manufacturing Using Deep Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38bf4bcd-8c59-4049-b6e9-1fde4161481b/download,University of Texas at Austin,"Layer-wise 3D surface morphology information is critical for the quality monitoring and
control of additive manufacturing (AM) processes. However, most of the existing 3D scan
technologies are either contact or time consuming, which are not capable of obtaining the 3D
surface morphology data in a real-time manner during the process. Therefore, the objective of this
study is to achieve real-time 3D surface data acquisition in AM, which is achieved by a supervised
deep learning-based image analysis approach. The key idea of this proposed method is to capture
the correlation between 2D image and 3D point cloud, and then quantify this relationship by using
a deep learning algorithm, namely, convolutional neural network (CNN). To validate the
effectiveness and efficiency of the proposed method, both simulation and real-world case studies
were performed. The results demonstrate that this method has strong potential to be applied for
real-time surface morphology measurement in AM, as well as other advanced manufacturing
processes.",,,,,,
"['Dunbar, Alexander J.', 'Nassar, Abdalla R.', 'Reutzel, Edward W.', 'Blecher, Jared J.']",2021-10-26T17:55:48Z,2021-10-26T17:55:48Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89540,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['monitoring', 'powder bed fusion', 'additive manufacturing']",A Real-Time Communication Architecture for Metal Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d760433e-88cd-40d5-b440-f15899e42562/download,University of Texas at Austin,"Recent advancements in the field of additive manufacturing continue to push its application deeper
into commercial use. However, concerns persist regarding the consistency of part quality,
methodologies for quality assurance, and cyber-physical system security. These concerns are
exacerbated by the closed-system architecture implemented by most commercial powder bed
fusion additive manufacturing (PBFAM) machine manufacturers. Though implementation of
device and process monitoring equipment is often suggested to address these concerns, deployment
is hampered by the inability to extract real-time information from closed systems during the build
process, including scanner position, laser power, sensor data, etc. Here, a framework for an open
and transparent communication protocol for PBFAM systems is developed and implemented on a
3DSystems ProX-200 machine. Real-time measurement of build process parameters and
synchronization with an optical emission sensor is demonstrated. The utility of the protocol and
real-time sensing for PBFAM are discussed.",,,,,,
"['Jariwala, Amit S.', 'Schwerzel, Robert E.', 'Rosen, David W.']",2021-10-04T20:34:38Z,2021-10-04T20:34:38Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88341', 'http://dx.doi.org/10.26153/tsw/15280']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Exposure Controlled Projection Lithography', 'stereolithography', 'real-time monitoring system', 'interferometry']",Real-Time Interferometric Monitoring System for Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/29594790-2c74-4672-967b-668cbcf8b3c2/download,University of Texas at Austin,"Stereolithography is an additive manufacturing process in which liquid photopolymer
resin is cross-linked and converted to solid polymer with an ultraviolet light source. Exposure
Controlled Projection Lithography (ECPL) is a stereolithographic process in which incident
radiation, patterned by a dynamic mask, passes through a transparent substrate to cure a
photopolymer layer that grows progressively from the substrate surface. In contrast to existing
stereolithography techniques, this technique uses a gray-scale projected image, or alternatively a
series of binary bit-map images, to produce a three-dimensional polymer object with the desired
shape, and it can be used on either flat or curved substrates.
Like most stereolithographic technologies, ECPL works in a unidirectional fashion.
Calibration constants derived experimentally are fed to the software used to control the system.
This unidirectional fabrication method does not, by itself, allow the system to compensate for
minor variations, thereby limiting the overall accuracy of the process. We present here a simple,
real-time monitoring system based on interferometry, which can be used to provide feedback
control to the ECPL process, thus making it more robust and increasing system accuracy. The
results obtained from this monitoring system provide a means to better visualize and understand
the various phenomena occurring during the photopolymerization of transparent photopolymers.",,,,,,
"['Ahn, S.', 'Murphy, J.', 'Ramos, J.A.', 'Wood, K.', 'Beaman, J.J.']",2019-10-22T18:27:55Z,2019-10-22T18:27:55Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76337', 'http://dx.doi.org/10.26153/tsw/3426']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Modification,Real-Time Measurement of Temperature for Control of Laser Surface Modification Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/06d73f6b-81d7-4b41-9367-270d9c1c4d46/download,,"The process of laser surface modification is a complex transient three-dimensional
heat conduction problem. A moving heat source and a moving phase boundary further
complicate the modeling. This general problem can be simplified using appropriate
assumptions resulting in an energy balance equation used to derive a melt depth model as
a function of interaction time and laser power input. The model can then be used to
design and implement a real-time feedback control scheme. The measurement used for
feedback to the control algorithm is the surface temperature. The real-time surface
temperature measurements are obtained by using a unique pyrometer arrangement. This
measurement scheme allows the pyrometer measurement aperture to directly follow the
laser beam path through the entire surface modification process in real-time. Experiments
using a Nd:YAG laser were performed on mild steel samples to verify the suggested
model’s results.","The Laboratory for Freeform Fabrication gratefully acknowledges the support of
the Office of Naval Research for funding the project “Surface Engineering for SFF
Processes,” Grant No: N00014-00-1-0334.",,,,,
"['Zhao, Xiayun', 'Rosen, David W.']",2021-11-02T20:03:28Z,2021-11-02T20:03:28Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89882,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['feedback control', 'real-time', 'in-situ', 'interferometric curing monitoring and measuring', 'exposure controlled projection lithography']",Real-Time Process Measurement and Feedback Control for Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bafb48a7-cdcb-413e-8dda-1ebd6701e3b6/download,University of Texas at Austin,"The Exposure Controlled Projection Lithography (ECPL) is an additive manufacturing
process that can cure microscale photopolymer parts on a stationary substrate with patterned
ultraviolet beams underneath. An in-situ interferometric curing monitoring and measuring
(ICM&M) system is developed to measure the ECPL process output of cured height profile.
This study develops a real-time feedback control system that utilizes the online ICM&M
feedback for automatically and accurately cure a part of targeted height. The experimental
results directly validate the ICM&M system’s real-time capability in capturing the process
dynamics and in sensing the process output, and evidently demonstrate the feedback control
system’s satisfactory performance in achieving the desired height despite the presence of
ECPL process uncertainties, ICM&M noises, and computing interruptions. A comprehensive
error analysis is reported, implying a promising submicron control with enhanced hardware.
Generally, the study establishes a paradigm of improving additive manufacturing with a real-time closed-loop measurement and control system.",,,,,,
"['Jones, Harrison H.', 'Kwatra, Abhishek', 'Jariwala, Amit S.', 'Rosen, David W.']",2021-10-07T15:21:21Z,2021-10-07T15:21:21Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88479', 'http://dx.doi.org/10.26153/tsw/15413']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Exposure Controlled Projection Lithography', 'real-time monitoring system', 'interferometry', 'photopolymerization']",Real-Time Selective Monitoring of Exposure Controlled Projection Lithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/688ac6f2-723d-4704-964c-85fbd32bc073/download,University of Texas at Austin,"Exposure Controlled Projection Lithography (ECPL) is a stereolithographic process in
which incident radiation, patterned by a dynamic mask, passes through a transparent substrate to
cure photopolymer which grows progressively from the substrate surface. We present here a
novel method of capturing useful information about the curing process from a simple,
inexpensive, real-time monitoring system based on interferometry. This approach can be used to
provide feedback control to the ECPL process, thus making the process more robust and
increasing system accuracy. The results obtained from this monitoring system provide a means to
better visualize and understand the various phenomena occurring during the photopolymerization of transparent photopolymers. In order to lessen the measurement error, caused
by internal diffraction within the substrate, the interferometry system has been designed such that
the laser light used can be selectively targeted. This selective monitoring approach is
experimentally validated to measure the height and profile of the cured part in real-time.",,,,,,
"['Knoppers, G. E.', 'Gunnink, J. W.', 'van den Hout, J.', 'van Vliet, W. P.']",2019-12-05T17:20:17Z,2019-12-05T17:20:17Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78650', 'http://dx.doi.org/10.26153/tsw/5706']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Graded Material,The Reality of Functionally Graded Material Products,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43b4ab9e-df5e-4906-8ddd-9050fef1aada/download,,"Rapid Manufacturing utilizes the application of different materials in parts by stacking a sequence of layers.
Based on the requirements of the part, mixtures of materials, so-called Functionally Graded Materials, can
be used to compose the product functionality. This process depends completely on the availability of CAD
information of the part geometry. Unfortunately, commercially available CAD-systems do not allow the design of graded material structures. TNO developed a computer tool which enables the user to specify Functionally Graded Materials. The system is based on a new approach to define the material composition at any
point in the solid.",,,,,,
"['Chen, X.', 'Wang, D.', 'Jiang, T.', 'Xiao, H.']",2021-11-16T15:05:46Z,2021-11-16T15:05:46Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90306', 'http://dx.doi.org/10.26153/tsw/17227']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['disturbance parameter', 'disturbance', 'control-oriented', 'realtime', 'powder bed fusion', 'additive manufacturing']",Realtime Control-Oriented Modeling and Disturbance Parameterization for Smart and Reliable Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6582a52b-dd4e-46ed-ad10-799149f597a5/download,University of Texas at Austin,"The vision of sustainable mass customization calls for additive manufacturing (AM) processes that
are resilient to process variations and interruptions. This work targets to pioneer a system-theoretical approach towards such a smart and reliable AM. The approach is based on control-oriented modeling of the process variations and on closed-loop model-based controls that facilitate
in-situ adjustment of the part quality. Specifically, one focused example is laser-aided powder bed
fusion. Building on the in-layer precision heating and solidification, together with layer-by-layer
iterations of the energy source, feedstock, and toolpath, we discuss mathematical abstractions of
process imperfections that will not only understand the intricate thermomechanical interactions
but are also tractable under realtime computation budgets. In particular, we develop and validate
a surrogate modeling of in-process disturbances induced by the periodic in- and cross-layer
thermomechanical interactions. This control-oriented disturbance modeling allows for the
adoption of high-performance control algorithms to advance AM quality in a closed loop, and we
show a first-instance study on the effect of repetitive controls in reducing melt-pool variations in
the periodic energy deposition.",,,,,,
"['Hu, X.', 'Jiang, T.', 'Lin, F.', 'Sun, W.']",2019-09-23T16:51:59Z,2019-09-23T16:51:59Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75968', 'http://dx.doi.org/10.26153/tsw/3067']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Boolean,"Reasoning Boolean Operation for Modeling, Simulation and Fabrication of Heterogeneous Objects 417",Conference paper,https://repositories.lib.utexas.edu//bitstreams/094f9da6-6187-4af8-a5b0-1821177b084d/download,,"An approach using reasoning Boolean operation to model heterogeneous object is presented. Algorithm in the reasoning Boolean operation consists of merging and extraction operation. This algorithm models heterogeneous object at multi-volume level. Due to its CAD-based nature, the model can be implemented with advanced CAD/CAE/CAM software for integrated design, simulation, and prototyping fabrication. Example of using the developed modeling technique to construct the heterogeneous composite unit cells, to perform integrated design and analysis, and to develop a pseudo-processing algorithm for layered fabrication of heterogeneous object is also presented.",We gratefully acknowledge the support from NSF 9980298 project funding to graduate student T. Jiang during the course of this research.,,,,,
"['Gan, M.X.', 'Wong, C.H.']",2021-11-02T19:21:53Z,2021-11-02T19:21:53Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89872,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'additive manufacturing', 'LAS', 'glass-ceramic', 'spodumene']",Recapitulation on Laser Melting of Ceramics and Glass-Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cde1b983-4cbd-415f-8baf-33e2ffbb392c/download,University of Texas at Austin,"Additive manufacturing of ceramics and glass-ceramics is becoming important due to
demands for high-performance applications and requirement for customizations. This is also
due to the high cost incurred by conventional methods for producing prototypes and functional
end parts of such inorganic materials. Despite the advantages that are already evident for direct
laser melting of metals, in-process challenges such as thermal stress induced cracks and
laser-material interactions have slowed down the progress and adoption of direct laser melting
for these inorganic and non-metallic materials. Nevertheless, several works have been carried
out to improve the process of direct laser melting of ceramics and glass ceramics despite the
various challenges posed. In this article, we recapitulate past studies and update the progress on
the additive manufacturing of ceramics and glass ceramics in particular by direct laser melting.
In addition, we discuss the relevance of laser melting of ceramics and glass-ceramics for future
roadmap.",,,,,,
"['Hilmas, Greg E.', 'Lombardi, John L.', 'Hoffman, Robert A.', 'Stuffle, Kevin']",2018-11-14T21:03:10Z,2018-11-14T21:03:10Z,1996,Mechanical Engineering,doi:10.15781/T2W37MF7G,http://hdl.handle.net/2152/70267,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['EFF', 'CAD', 'freeform fabrication technologies']",Recent Developments in Extrusion Freeform Fabrication (EFF) Utilizing Non-Aqueous Gel Casting Formulations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/08118833-e622-4068-b15b-179861d91d3d/download,,"Extrusion Freeform Fabrication (EFF) was shown to be an extremely versatile method for
fabricating Functionally Graded Materials (FGMs) The approach is inexpensive and potentially
feasible for grading between any thermodynamically compatible ceramic-metal, ceramic-ceramic,
or metal-metal material combination. Several material systems were investigated in this study
including alumina-304 stainless steel, zirconia-304 stainless steel, alumina-Inconel 625, zirconiaInconel625,
alumina-nickel aluminide, zirconia-nickel aluminide, titanium carbide-InconeI625,
titanium diboride-nickel aluminide, and tungsten carbide-nickel aluminide. A controlled gradient
was demonstrated between the end members for all of the above compositions. The FGMs were
hot pressed to achieve near theoretical densities, providing flexural strengths as high as 1000 MPa
for the zirconia-304 stainless steel FGM.
The FGM systems developed in this program have a wide variety of potential commercial and
government applications including cutting tools and other components requiring wear resistant
surfaces, aircraft engine and automotive engine components, light and heavy armor systems, and
electrical insulators and heat-sinks for the electronics industry, to name a few",,,,,,
"['Cesarano TIl, Joseph', 'Baer, Thomas A.', 'Calvert, Paul']",2018-11-28T17:21:40Z,2018-11-28T17:21:40Z,1997,Mechanical Engineering,doi:10.15781/T2GF0NG4Z,http://hdl.handle.net/2152/70322,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['freeform fabrication', 'dense ceramic', 'Robocasting']",Recent Developments in Freeform Fabrication of Dense Ceramics From Slurry Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/89ef35a3-f69a-4e59-bd7e-1ee2d9e522aa/download,,"A freeform fabrication technique for dense ceramics and composites has been developed.
The technique requires less than 2 volume percent of organic additives and relies on the principle
of layerwise deposition of highly loaded colloidal slurries. Components can be manufactured
into complex geometries with thick solid sections as well as with thin-walled sections with high
aspect ratios. Process feasibility and quality is dependent on the processing parameters ofsolids
loading, slurry rheology, deposition rate, and drying rate. These interrelated parameters must be
controlled so that sintering defects are prevented and shape tolerance is maintained. A review of
this freeform fabrication technique, called robocasting, will be discussed for fabrication of
aluminum oxide parts. Recent developments for a finite element analysis technique for
modelling the drying process will also be presented.",,,,,,
"['Himmer, Thomas', 'Techel, Anja', 'Nowotny, Steffen', 'Beyer, Eckhard']",2019-10-24T18:25:06Z,2019-10-24T18:25:06Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77419', 'http://dx.doi.org/10.26153/tsw/4508']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Laser Processing,Recent Developments in Laminated Tooling by Multiple Laser Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a0f79144-1172-4224-ac78-93fed8a7bbbd/download,,,"This research and development project is founded by the German Federal Ministry of
Education and Research (BMBF) within the framework concept ""research for the production
of tomorrow"" and cared by the agency “Production and Production Technologies” (PFT) at
the Forschungszentrum Karlsruhe.",,,,,
"['Walczyk, Daniel F.', 'Hardt, David E.']",2018-11-14T16:42:40Z,2018-11-14T16:42:40Z,1996,Mechanical Engineering,doi:10.15781/T2D795W86,http://hdl.handle.net/2152/70237,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['PEL die fabrication', 'CNC machining', 'laminated construction']",Recent Developments in Profiled-Edge Lamination Dies for Sheet Metal Forming,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f517161d-a3cb-4860-ad17-ae2c9639fac4/download,,"The Profiled-Edge Lamination (PEL) method was developed by the Walczyk and Hardt as an improvement oer the current method of stacking and bonding contured laminations in
terms of the lead-time and cost of toolIng development for sheet metal forming dies. It is also a
viable alternative to conventional CNC-machining of such dies. In pursuit of successful
commercial realization of the PEL method in industry, this paper discusses several important issues
including:
• the origin of this method and advantages over other tooling techniques
• the general procedure for creating PEL machining instructions
• determining the geometric error introduced by the straight bevel approximation
• the propensity for PEL die delamination from high forming loads
• methods for cutting bevels into die laminations and
• the machinery needed for PEL die fabrication.
Future research and developmental work on the PEL die method will also be outlined.",,,,,,
"['Cesarano Ill, Joseph', 'King, Bruce H.', 'Denham, Hugh B.']",2019-03-01T17:32:48Z,2019-03-01T17:32:48Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73516', 'http://dx.doi.org/10.26153/tsw/666']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['ceramic powder', 'colloidal slurries']",Recent Developments in Robocasting of Ceramics and Multimaterial Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fcdde209-c17b-46ae-965b-046d907fbb79/download,,"Robocasting is a freeform fabrication technique for dense ceramics and composites that is
based on layer-wise deposition of highly loaded colloidalslurries. The process is essentially
binderless with less than 1% organics and parts can be fabricated, dried, and completely sintered
in less than 24 hours. This overview will highlight recent materials developments for structural
applications and modelling of slurry flow. Fabrication of preforms for alumina/metal
composites will be discussed as well as techniques for multimaterial deposition in both graded
structures and discrete placement of fugitive materials.",,,,,,
"['Wang, Pan', 'Nai, Mui Ling Sharon', 'Tan, Xipeng', 'Vastola, Guglielmo', 'Raghavan, Srinivasan', 'Sin, Wai Jack', 'Tor, Shu Beng', 'Pei, Qing Xiang', 'Wei, Jun']",2021-10-27T21:37:15Z,2021-10-27T21:37:15Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89622,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'titanium alloy', 'microstructure', 'mechanical properties', 'phase transformation', 'porosity', 'surface finishing', 'residual stress', 'simulation']",Recent Progress of Additive Manufactured Ti-6Al-4V by Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8a187aa1-aca9-4744-bfe7-0a446fccb16f/download,University of Texas at Austin,"Electron beam melting (EBM) is one of the powder-bed fusion additive manufacturing
technologies. This technology is very suitable for producing near-net-shape small to medium
volume metallic parts with complex geometries. However, layer-by-layer fusion step
introduces rapid thermal cycles, which results in a different microstructure as compared to their
cast or wrought counterparts. Therefore, the microstructure and mechanical properties
produced by EBM must be better understood and in turn to control the microstructure for
requirements of some specific applications. Accordingly, in this paper, an insight will be
provided on the effort of understanding the microstructure and mechanical properties from
atomic scale to real complex big-sized industrial components. The spatial- and
geometrical-based microstructure and mechanical properties of EBM Ti-6Al-4V as well as the
effect of heat treatment on them were investigated using atom probe tomography, transmission
electron microscopy, scanning electron microscopy, optical microscopy, x-ray diffraction,
x-ray computed tomography, nanohardness testing, microhardness testing, tensile testing and
finite element simulations. The microstructure and deformation mode depend on both the build
thickness and build height which are closely linked to the heat input and the cooling rate in
EBM process. Furthermore, the control of microstructure by varying the process parameters
and heat treatment schemes was also proposed. By using these findings, an impeller prototype
with a base diameter of 100 mm, a height of 53 mm and thinnest sections of ~0.7 mm and a
turbine blade prototype with dimensions of 180×70×360 mm were successfully fabricated by
EBM. These components exhibited an overall improved combination of strength and ductility
as compared to the counterparts fabricated by conventional methods. These results revealed
that EBM is a promising method for fabricating complex-shaped industrial components with
superior mechanical performance for practical application.",,,,,,
"['Kirka, Michael', 'Bansal, Rohan', 'Das, Suman']",2021-09-29T20:18:39Z,2021-09-29T20:18:39Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88212', 'http://dx.doi.org/10.26153/tsw/15153']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['scanning laser epitaxy', 'single crystal superalloys', 'nickel-based superalloys', 'single-crystal turbine engine components']",Recent Progress on Scanning Laser Epitaxy: A New Technique for Growing Single Crystal Superalloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0ffab28-a80a-4540-86ea-6da61d610386/download,University of Texas at Austin,"This paper presents recent progress on scanning laser epitaxy, a laser manufacturing
technique being developed for achieving single crystal growth in nickel‐based superalloys.
Investigations have been performed for creating monolithic deposits on like chemistry
single‐crystal nickel superalloy substrates. Progress in the areas of microstructure development
and process control will be discussed in the context of repairing high‐value single‐crystal turbine
engine components. This work is funded by the Office of Naval Research contract
#N00173‐07‐1‐G012.",,,,,,
"['Dwivedi, Rajeev', 'Sinha, Ayush', 'Ebburu, Pranav', 'Saxena, Yash', 'Haque, Shabab', 'Kulkarni, Shaunak']",2021-10-28T20:41:24Z,2021-10-28T20:41:24Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89695,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['work envelope', 'solid freeform fabrication', 'drive limitations']",A Reconfigurable System to Enhance the Work Envelope of a Solid Freeform Fabrication System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d177bbcc-c3e4-4d83-a317-464913c778bb/download,University of Texas at Austin,"Size and aspect ratio of parts created by Solid freeform fabrication systems is limited by the
configuration of equipment. Also referred to as Axes, the maximum reach of material deposition
end effector determines the maximum size of the part that can be built. Inherent to most the SFF
system is the drive configuration that limits the extent of the reach of the end effector. This paper
proposes an alternate architecture that overcomes the drive limitations and hence provides an
ability to enhance the work envelope. Two systems proposed include – (1) Cartesian axis
stacking and (2) Common Vehicle arrangement. The system drive may be built such that multiple
units can be combined and reconfigured to expand the total work envelope.",,,,,,
"['Sutton, Austin T.', 'Kriewall, Caitlin S.', 'Leu, Ming C.', 'Newkirk, Joseph W.']",2021-11-11T14:52:22Z,2021-11-11T14:52:22Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90208', 'http://dx.doi.org/10.26153/tsw/17129']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['recyclability', 'reuse', '304L', 'stainless steel', 'selective laser melting']",Recyclability of 304L Stainless Steel in the Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/27413124-ef05-43ca-ac9a-66fd13abb558/download,University of Texas at Austin,"During part fabrication by selective laser melting (SLM), a powder-bed fusion process in
Additive Manufacturing (AM), a large amount of energy is input from the laser into the melt pool,
causing generation of spatter and condensate, both of which have the potential to settle in the
surrounding powder-bed compromising its reusability. In this study, 304L stainless steel powder
is subjected to five reuses in the SLM process to assess its recyclability through characterization
of both powder and mechanical properties. Powder was characterized morphologically by particle
size distribution measurements, oxygen content with inert gas fusion analysis, and phase
identification by X-ray diffraction. The evolution of powder properties with reuse was also
correlated to tensile properties of the as-built material. The results show that reused powder
coarsens and accrues more oxygen with each reuse. The effects of powder coarsening and oxygen
increase on the tensile properties of fabricated parts are being investigated.",,,,,,
"['Walker, Roo', 'Smith, Tyler', 'Lindahl, John', 'Hershey, Christopher', 'Kunc, Vlastimil', 'Duty, Chad']",2021-12-06T21:49:51Z,2021-12-06T21:49:51Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90684', 'http://dx.doi.org/10.26153/tsw/17603']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['CF-ABS', 'recycling', 'printability', 'large-scale additive manufacturing', 'LSAM']",Recycling Carbon Fiber Filled Acrylonitrile-Butadiene-Styrene for Large Format Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de30e1d1-5756-4bd7-969f-1e79d8df8799/download,University of Texas at Austin,"The recovery, recycling, and reuse of large format additive manufacturing (LFAM)
composite scrap material as a secondary feedstock material is essential for the feasibility of large-scale AM (LSAM) sustainability. Carbon fiber reinforced acrylonitrile butadiene styrene (CF-ABS) was recycled and used as a secondary LSAM feedstock material to understand printability
behaviors against that of virgin feedstock materials. Each material was printed on the Big Area
AM system. Rheological and preliminary fiber length were evaluated. Rheological
characterization was used to determine if the recycled feedstock materials were viable for printing.
Fiber analysis was performed to gain understanding of fiber degradation in the recycling process.
By successfully characterizing the impact of incorporating secondary feedstocks in large-scale
AM, a pathway can be defined for further reducing material waste and improving AM
sustainability.",,,,,,
"['Mohammed, Mazher Iqbal', 'Wilson, Daniel', 'Gomez-Kervin, Eli', 'Vidler, Callum', 'Rosson, Lucas', 'Long, Johannes']",2021-11-09T14:29:42Z,2021-11-09T14:29:42Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90080', 'http://dx.doi.org/10.26153/tsw/17001']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'FFF', 'polymer', 'solar', 'e-waste', 'humanitarian aid']",The Recycling of E-Waste ABS Plastics by Melt Extrusion and 3D Printing Using Solar Powered Devices as a Transformative Tool for Humanitarian Aid,Conference paper,https://repositories.lib.utexas.edu//bitstreams/672d49b3-e773-4d2b-b84b-3395403e2b8c/download,University of Texas at Austin,"This study demonstrates the EcoPrinting principal, which makes use of renewable energy to
realise a low carbon footprint means of recycling waste plastics into feedstock for Fused Filament
Fabrication (FFF) 3D printing. We present our work to date to encapsulate this principal in a singular
device, which comprises a nanogrid solar/battery storage unit, a custom made filament extrusion
device and modified FFF 3D printer system. We demonstrate that our system is capable of reforming
ABS plastics found in electronic waste and converting these into functional items through a melt
extrusion and additive manufacturing process. We successfully demonstrate the efficacy of the system
to operate using solar derived energy and using the resulting filament to 3D print functional pipe
connector components. We conclude Ecoprinting holds considerable potential as a sustainable means
of converting waste plastics into functional components. Finally, the portable and self-sufficient
nature of the system, Ecoprinting could feasibly could be applied as a cost effective aid solution for
vulnerable communities in low socio-economic environments.",,,,,,
"['Prasad, K. Siva', 'Rathakrishnan, E.', 'Dhande, Sanjay G.']",2019-11-21T18:10:29Z,2019-11-21T18:10:29Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78551', 'http://dx.doi.org/10.26153/tsw/5607']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Casting Technique,Recycling of RP Models by Solution - Casting Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2e72495f-3da6-4ccf-8079-438f1821c5ac/download,,"Most of the Rapid Prototyping systems process polymeric materials for model making.
Increased environmental concerns and waste minimization demands the recycle of these
polymeric models. One way is to melt the models and cast it. However, in this method
polymer degradation may occur leading to diminished functionality. In the present work a
preliminary attempt has been made to reuse the polymer components by dissolving in a
suitable solvent and casting the same into the required shape using soft tooling. Acrylonitrile
Butadiene Styrene (ABS) polymer components, made by Fused Deposition Modeling (FDM)
process were taken for the present study",,,,,,
"['Engle, J.', 'Nguyen, R.', 'Buah, K.', 'Weaver, J.M.']",2021-11-18T18:15:47Z,2021-11-18T18:15:47Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90453', 'http://dx.doi.org/10.26153/tsw/17374']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['ambient lighting', 'visual contrast', 'in-process monitoring', 'smart lighting', 'colorization system', '3D printing']",Reducing Computer Visualization Errors for In-Process Monitoring of Additive Manufacturing Systems Using Smart Lighting and Colorization System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7caa1520-3a7d-42a0-8014-79cccb7c8695/download,University of Texas at Austin,"Computer vision systems that monitor additive manufacturing processes are susceptible
to producing false-positive errors for defects. Two of the main sources for these errors come
from uncontrolled ambient lighting and insufficient visual contrast between prints and their
backgrounds. This paper presents a method for controlling ambient lighting and increasing visual
contrast for an in-process monitoring system for a 3D printer, using a light-filtering camera
enclosure and a smart lighting and colorization system. A single-camera in-process monitoring
system was developed and used to visually inspect a series of identical test prints. Various error
classes, including false-positive error rates, were tested and measured for the camera system,
comparing the results of including a blackout enclosure and a smart lighting system against using
the camera system alone. Recommendations for future development of lighting and colorization
systems are suggested.",,,,,,
"['Duty, Chad', 'Failla, Jordan', 'Kim, Seokpum', 'Lindahl, John', 'Post, Brian', 'Love, Lonnie', 'Kunc, Vlastimil']",2021-11-04T14:21:43Z,2021-11-04T14:21:43Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89968,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['vertical material deposition', 'z-pinning', 'mechanical anisotropy', 'extrusion-based printing', '3D printing', 'patent-pending']",Reducing Mechanical Anisotropy in Extrusion-Based Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4bf7556-69d9-48bc-a3d8-329781a08056/download,University of Texas at Austin,"The mechanical performance of 3D printed components is highly dependent upon the
orientation of the part relative to the build plane. Specifically for extrusion-based printing systems,
the bond between successive layers (z-direction) can be 10-25% weaker than in the printed plane
(x-y plane). As advanced applications call for fiber reinforced materials and larger print systems
(such as the Big Area Additive Manufacturing system) extend the layer time, mechanical
performance in the z-direction can decrease by 75-90%. This paper presents a patent-pending
approach for improving mechanical performance in the z-direction by depositing material
vertically across multiple layers during the build. The “z-pinning” process involves aligning voids
across multiple (n) layers, which are then back-filled in a continuous fashion during the deposition
of layer (n+1). The “z-pinning” approach has been demonstrated to be an effective approach for
increasing the strength (20% increase) and toughness (200% increase) of printed parts in the z-direction.",,,,,,
"['Forderhase, Paul', 'Corden, Richard']",2018-05-03T17:19:19Z,2018-05-03T17:19:19Z,1993,Mechanical Engineering,doi:10.15781/T27S7J93X,http://hdl.handle.net/2152/65043,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Sinterstation 2000', 'anchors', 'experimental data', 'Thermal Distortion']",Reducing or Eliminating Curl on Wax Parts Produced in the SinterstationTM 2000 System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a9f3432-e94a-4153-85ef-bb33d3e40bc3/download,,,,,,,,
"['Reeves, P.E', 'Cobb, R.C..']",2019-02-19T20:05:52Z,2019-02-19T20:05:52Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73442', 'http://dx.doi.org/10.26153/tsw/594']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Layer Manufacturing Technologies', 'Rapid Tooling']",Reducing the Surface Deviation of Streolithographpy Using an Alternative Build Strategy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d4b8d8e-b87a-4370-bc89-4e9ce241c3fa/download,,"Considerable research has been undertaken to assess the suitability of different post-process
finishing techniques, when used to reduce the surface deviation of Stereolithography
components. Such techniques are however limited, as irregular roughness on the SL master often
results in a loss in geometric integrity before the desired finish is achieved. Hence, removing
much ofthe design intent and traceabilty within the automated fabrication process. Although a
number of research initiatives have been undertaken to design layer manufacturing systems
which produce inherently smooth surface, the problem of finishing parts from existing. systems
remains. The solution currently under investigation by the author is to develop a smooth build
cycle within the SL machine, eliminating the need for costly machine modifications.
The solution developed by the author uses a strategy, which relies on both part orientation and a
fundamental change to the current SLA build cycle. By orientating parts into an optimum build
direction, the paper shows how naturally occurring phenomena within the SL process can be
used to produce low roughness over a 50-degree window of surfaces. The paper·goes on to
demonstrate how, by using a resin meniscus scanned between layers during the·buildiprocess,
this smooth envelope can be extended to encompass 90-degree .of surfaces. By scanning fillets
between each layer, a reduction in surface roughness of up to 400% can be achieved on some
angled planes. The paper concludes that by using this new build algorithm,·the roughness of SL
tool cavities can be maintained below 9Jlm Ra on all surfaces. Hence, reducing or even
eliminating the need for post-process finishing on all but the most accurate cavities.",,,,,,
"['Ullett, Jill S.', 'Chartoff, Richard P.', 'Lightman, Allan J.', 'Murphy, John P.', 'Li, Jinghong']",2018-10-03T15:41:54Z,2018-10-03T15:41:54Z,1994,Mechanical Engineering,doi:10.15781/T2CZ32Q3Z,http://hdl.handle.net/2152/68651,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'Resin shrinkage', 'vector randomization']",Reducing Warpage In Stereolithography Through Novel Draw Styles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc3be269-1239-4e2e-9815-e7ccd6fa9011/download,,"A consistent problem with stereolithography has been part distortion and
dimensional inaccuracies caused by resin shrinkage. Resin shrinkage and, thus, warpage
occurs during the build process and during the postcure. Build parameters such as draw
pattern (the order in which strands are drawn by the laser) and overcure (cure depth minus
slice thickness) can affect overall part warpage by minimizing the warpage of individual
strands and layers. A software package, PATTERNDRAW, developed at the University of
Dayton allows an SLA operator to manipulate vector files and change the pattern by which
layers, slices, are filled in. This software was used to study the effects of draw pattelTI,
vector segmentation"" and cure depth on warpage of parts of different sizes. All parts were
made using Ciba-Geigy 5081-1 resin. Moire analysis was used to measure out-of-plane
deflections of part surfaces. Result~ indicate that significant reductions in warpage can be
achieved by the use of novel draw styles.",,,,,,
"['Gervasi, Vito R.', 'Cook, Douglas']",2021-09-28T18:27:39Z,2021-09-28T18:27:39Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88148', 'http://dx.doi.org/10.26153/tsw/15089']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['shell-slice', 'decomposition', 'hybrid fabrication', 'least-core', 'lattice structures', 'cellular structures']",Reduction of Complex Objects into Manufacturable Elements Using the Shell-Slice Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e3f9b98-2a0e-4c09-acf1-34f8a0d2c83e/download,University of Texas at Austin,"Software tools for generating a parting surface around a molded part have been available for many years
and could be of use for additive fabrication of complex objects. This paper explores the use of software
tools such as Materialise Magics Tooling TM and SolidWorks® software to assist in reducing complex
objects, such as a lattice structure, into sub-elements free of undercuts and hidden internal geometry. The
objective of the proposed Shell-Slice approach is to decompose an object into elements that can be readily
machined and created via hybrid fabrication processes. The appeal of hybrid fabrication combined with
an automated Shell-Slice approach, is the machinability of each sub-element parting-surface and the
remarkable build-speeds and surface-finishes that may be attainable.",,,,,,
"['Bevan, D. R.', 'Mouton, S. A.']",2020-03-05T20:24:14Z,2020-03-05T20:24:14Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80158', 'http://dx.doi.org/10.26153/tsw/7179']",eng,2006 International Solid Freeform Fabrication Symposium,Open,FASTOOL,Reduction of Machine Tool Times Through a Software/Hardware Integrated Solution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bef62a1b-6deb-4f00-bd17-7bdfa788ab94/download,,"Toolmaking is an industry that creates metal moulds, generally of durable tool steels, for
producing vacuum-formed and injection moulded plastic parts, which are used in thousands
of everyday items such as mobile phones. At present toolmaking is labour intensive with each
machining operation requiring manual supervision. The FASTOOL project was a European
Union funded collaboration that was aimed at reducing the manpower content of mould
toolmaking, and extending the working day. This paper focuses on one element which utilised
specially created scheduling and control software that operated an automated overhead gantry
system and could remotely start the workshop machines. The software was completely object
oriented which allows future proofing by creating new objects for new machines. The results
demonstrate that this manufacturing process can be automated, leading to better working
conditions for employees and an increase in efficiency and profitability.",,,,,,
"['Patrick, Steven', 'Nycz, Andrzej', 'Noakes, Mark']",2021-11-11T16:16:29Z,2021-11-11T16:16:29Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90233', 'http://dx.doi.org/10.26153/tsw/17154']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['reinforcement learning', 'toolpaths', '3D printing', 'additive manufacturing']",Reinforcement Learning for Generating Toolpaths in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/188b5ff0-b6f6-4743-904d-65bcc642fb84/download,University of Texas at Austin,"Generating toolpaths plays a key role in additive manufacturing processes. In the case of 3-Dimensional
(3D) printing, these toolpaths are the paths the printhead will follow to fabricate a part in a layer-by-layer
fashion. Most toolpath generators use nearest neighbor (NN), branch-and-bound, or linear programming
algorithms to produce valid toolpaths. These algorithms often produce sub-optimal results or cannot handle
large sets of traveling points. In this paper, the researchers at Oak Ridge National Laboratory’s (ORNL)
Manufacturing Demonstration Facility (MDF) propose using a machine learning (ML) approach called
reinforcement learning (RL) to produce toolpaths for a print. RL is the process of two agents, the actor
and the critic, learning how to maximize a score based upon the actions of the actor in a defined state
space. In the context of 3D printing, the actor will learn how to find the optimal toolpath that reduces
printhead lifts and global print time.",,,,,,
"['Nelson, J.C.', 'Barlow, J.W.']",2018-04-19T18:19:16Z,2018-04-19T18:19:16Z,1992,McDonald Observatory,doi:10.15781/T2RB6WK2Z,http://hdl.handle.net/2152/64403,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['SLS model', 'SLS operators', 'SLS machines', 'one-dimensional']",Relating Operating Parameters between SLS Machines which have Different Scanner Geometries and Laser Spot Sizes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c16e8143-bd9a-497f-9cee-b21590772b60/download,,"As the number of SLS machines in operation increases, the opportunities to
share operating parameters with other SLS operators also increases. However, if the
machines are not identical down to the spot size of the laser beam, the quality of parts
made on each machine can be different. The most likely differences between two SLS
machines are the laser spot size and the scanning radius of the optics. The total energy
flux to the powder surface is a function of the spot size and the scan speed. The
algorithms defined to correct for machine differences are verified both experimentally and
numerically using a one-dimensional empirical SLS model.",,,,,,
"['Capps, Nicholas E.', 'Urban, James S.', 'West, Brian', 'Lough, Cody', 'Replogle, Adriane', 'Hartwig, Troy', 'Brown, Ben', 'Bristow, Douglas A.', 'Landers, Robert G.', 'Kinzel, Edward C.']",2021-11-02T13:30:10Z,2021-11-02T13:30:10Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89796,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['engineering properties', 'tensile', 'strength', 'modal properties', 'selective laser melting']",Relating Processing of Selective Laser Melted Structures to Their Material and Modal Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2cde9b1d-64c7-4d95-8641-41c2173ea5bd/download,University of Texas at Austin,"Selective Laser Melting (SLM) creates metal parts by fusing powder layer-by-layer. It
provides significant design flexibility and the possibility of low-volume production. The
engineering properties of the printed metal are a function of the local thermal history. This creates
challenges for validating Additively Manufactured (AM) parts. This paper correlates the
engineering properties (density, modulus, yield strength and ultimate strength) for tensile test
specimens created with different process parameters with the resonant frequencies determined
using modal testing. The paper shows that yield and ultimate strengths for these specimens can be
determined using modal analysis.",,,,,,
"['Thomas, Akshay J.', 'Barocio, Eduardo', 'Kapre, Vasudha', 'Pibulchinda, Pasita', 'Nguyen, Felix N.', 'Pipes, R.  Byron']",2023-01-26T21:32:39Z,2023-01-26T21:32:39Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117323', 'http://dx.doi.org/10.26153/tsw/44204']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Fiber Orientation', 'Spring-in', 'Virtual Characterization']",Relationship between flow-controlled fiber orientation and spring-in deformation in extrusion deposition additive manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03c9c4d0-3003-487e-9366-95c0ed275b89/download,,"ctures in the scale of multiple meters owing to enhanced stiffness and lower coefficient of thermal 
expansion primarily in the printing direction. Developing manufacturing process simulations for EDAM requires 
extensive material characterization including mechanical, thermal, viscoelastic, and thermomechanical property 
characterization. Further, varying the bead deposition conditions alter the fiber orientation state of the composite, 
thereby resulting in different anisotropic material properties. This increases the amount of characterization 
required to enable the digital twin framework. Therefore, we present a framework to infer the fiber orientation 
properties by conducting limited tensile tests at the composite coupon level. Using the inferred orientation state, 
we predict the unmeasured mechanical and thermomechanical properties and bypass the need for their 
experimental characterization. We present the application of this framework to predict the spring-in deformation 
of a geometry of interest printed using different process conditions.",,,,,,
"['Kigure, T.', 'Yamauchi, Y.', 'Niino, T.']",2021-11-18T01:44:24Z,2021-11-18T01:44:24Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90398', 'http://dx.doi.org/10.26153/tsw/17319']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['PA12', 'microstructure', 'low-temperature process', 'powder bed temperature', 'selective laser sintering']",Relationship Between Powder Bed Temperature and Microstructure of Laser Sintered PA12 Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ae14aedd-18e1-4db8-9205-9db0d707cd99/download,University of Texas at Austin,"The microstructure of a part from semi-crystalline polymers used in laser sintering gives a
significant impact on the mechanical properties of the parts. The microstructure of laser
sintering parts depends on powder bed temperature. If the powder bed temperature can be set
in a wide range, it is also possible to control the microstructure of a part.
The authors have been introducing a modified laser sintering process, namely low temperature
process. The process allows powder bed temperature being set wide range.
In this research, relationship between microstructure of PA12 parts by low-temperature process
and powder bed temperature is investigated. As a result, high strength and crystallinity were
obtained in high powder bed temperature, and high ductility and low crystallinity were obtained
in low powder bed temperature.
This result indicates that parts having the desired mechanical properties can be obtained by
controlling the powder bed temperature.",,,,,,
"['Cariapa, V.', 'Liang, S.K.', 'Brower, W.E.']",2018-04-12T18:28:25Z,2018-04-12T18:28:25Z,1991,Mechanical Engineering,doi:10.15781/T2639KN98,http://hdl.handle.net/2152/64281,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical and Industrial Engineering', 'Taguichi system', 'stereolithography']",The Relationship of Process Characteristics of Stereolithography to Prototype Dimensions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d53fae1c-07ef-4847-ba22-92771ac9de3f/download,,"A characteristic of the modem·day world is a continuous need ever changing designs of
high quality products. This characteristic, along>with lower cost of comp\.iting,has led to the
development of novel methods for reducing the cycle time of product development order for
companies to gameracompetitiveedge.I>esk top. manufacturing or rapid prototyping such
fieldoftechl1()logywhich• enablesco.mpaniesto rapidlyproduee.a three· dimension<model from a
computer data base. An overview of this rapidly expanding field is given in IS Among the more
common ofthese modem processes arestereolithography (SLI) [2,3], the DTM process [6], powder
metallurgyprototyping [4], and metal spraying of stereolithography pam [8].
An overview ofthe stereolithographyprocess has been presented in [3].
process characteristics and a generalprojection oftoleraneevalues of finished
been identified in [1,7]. However, the relationship between the two has the
available literature. This research focuses on· developing a more quantitative understanding of
important process parameters and dimensions of finished pam that are using
stereolithography.",,,,,,
"['Bocking, Chris', 'Rennie, Allan E. W.', 'Bennett, G.R.']",2019-09-23T17:05:31Z,2019-09-23T17:05:31Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75974', 'http://dx.doi.org/10.26153/tsw/3073']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Electroformed,Relationships Between Wall Thickness and Erosion Depth of Thin Walled Electroformed EDM Electrodes Produced From RP Models 469,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4442fc0-391d-4cce-8859-9aa45bbddf77/download,,"Metal filled thin walled electroformed EDM electrodes, fabricated using RP models, have been shown to be an effective route to producing die sink electrodes. However, due to the nature of electroforming, there are certain limits to the maximum depth of erosion of cavities that can be achieved, this being related to the electrode wall thickness. This initial study examines the relationship between the electrode wall thickness and depth of erosion.",,,,,,
"['Jones, Jason', 'McNutt, Phil', 'Tosi, Riccardo', 'Perry, Clinton', 'Wimpenny, David']",2021-10-06T21:51:25Z,2021-10-06T21:51:25Z,8/16/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88455', 'http://dx.doi.org/10.26153/tsw/15392']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['remanufacturing', 'laser cladding', 'inspection', 'additive manufacturing (AM)', 'adaptive machining', 'hybrid processing', 'repair']","Remanufacture of Turbine Blades by Laser Cladding, Machining and In-Process Scanning in a Single Machine",Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf64cc28-b99e-44a8-ae6e-ee32fb920294/download,University of Texas at Austin,"Remanufacturing is one of the most efficient ways of recycling worn parts because it
consumes only a fraction of the energy, cost, and material required for new parts.
Remanufacture of engineering components typically entails serial labor intensive and
operator skill sensitive processes, often requiring parts to move between
manufacturers and subcontractors. Unfortunately the logistics and quality assurance
measures required for effective remanufacturing currently restrict its implementation
primarily to high value components (e.g. turbine blades, blisks, etc.). This research
reports progress toward an integrated production system which combines laser
cladding, machining and in-process scanning in a single machine for flexible and lean
remanufacturing.",,,,,,
"['Chadha, Charul', 'Patternson, Albert E.', 'Allison, James T.', 'James, Kai A.', 'Jasiuk, Iwona M.']",2021-11-18T19:11:01Z,2021-11-18T19:11:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90473', 'http://dx.doi.org/10.26153/tsw/17394']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['damage repair', 'additive manufacturing', 'fused deposition modeling', 'plastic materials']",Repair of High-Value Plastic Components Using Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7fbb409-14d3-4321-a881-d85dfe68571a/download,University of Texas at Austin,"Recent focus on light-weight design and fuel efficiency in several sectors (such as aerospace
and automotive), as well as advances in polymer technologies, have made plastic parts more viable for
high-value systems. These are often low-production, high-precise parts which require expensive tooling
for traditional manufacture, making them difficult to reproduce later; this is especially true when the
original tooling is no longer available, and full additive manufacturing (AM) is infeasible. This study
explores the application of fused deposition modeling (FDM - extrusion-based AM) in the repair of cracks,
chips, and broken features in such plastic parts. A framework for repairing various kinds of plastic parts
using FDM is presented, including establishment of repair candidacy, selection of repair material and
parameters, post-processing, and repair evaluation. Three case studies, one repairing an optimized truss,
one exploring the use of sewing-stitch patch patterns, and one replacing a broken part feature, were
developed to demonstrate the presented concepts.",,,,,,
"['Gill, David', 'Smugeresky, John', 'Atwood, Clinton J.']",2020-03-05T20:26:43Z,2020-03-05T20:26:43Z,2006,English,,"['https://hdl.handle.net/2152/80160', 'http://dx.doi.org/10.26153/tsw/7181']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Laser Engineered Net Shaping,Repeatability Analysis of 304L Deposition by the LENS® Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d6762abc-ae3c-4af9-a403-f41bbb46c222/download,,"Sandia National Laboratories is currently engaging in an effort to qualify Laser Engineered Net
Shaping™ (LENS®) as a repair and modification process for high rigor metal components. As
part of that effort, the LENS team has conducted a process repeatability test to help identify
variation within the system. This test utilized 304L stainless steel which is a commonly used
material at Sandia. Over the course of 12 weeks, 3/8”x3/8”x2” towers were built in sets of 3
with a total of 30 towers completed. A random sampling of 10 of these towers (1 from each set
of 3) had been identified before depositing the towers, and these towers were used for tensile
testing and metallographic testing. The testing showed the ultimate and yield strengths of all
samples to be well above those of annealed 304L. This is expected because of the rapid melt
pool solidification present in the LENS process and the resulting grain refinement. The ductility,
which usually remains on par with annealed 304L, was found to be lower. The final cause of this
loss of ductility was determined to be inter-layer separation due to loose wires in the closed loop
melt pool control system.",,,,,,
"['Whiting, Justin G.', 'Tondare, Vipin N.', 'Moylan, Shawn P.']",2023-01-26T14:20:27Z,2023-01-26T14:20:27Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117304', 'http://dx.doi.org/10.26153/tsw/44185']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Repeatability and Sensitivity of a Rotating Drum Method for Rheological Characterization of Stainless Steel Powders Used for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/878ffeb1-8756-4c45-ad19-2f21f0001d3a/download,,"There remains a need for rheological characterization of metal powder used for powder-
spreading-based additive manufacturing (AM). Novel powder rheometers introduced to the 
commercial market for this purpose must be rigorously evaluated for repeatability and sensitivity 
before widespread adoption for predicting AM powder performance.  The work presented here 
focuses on the quantification of the repeatability and sensitivity of a commercially available 
rotating drum powder rheometer for testing metal AM powder.  This assessment is accomplished 
via a set of tests that include the following independent variables: cleaning method, the mass of 
the sample, particle size distribution, material, and hysteresis.",,,,,,
"['Kumar, Ashok V.', 'Wood, Aaron']",2019-03-12T16:19:26Z,2019-03-12T16:19:26Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73596', 'http://dx.doi.org/10.26153/tsw/738']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SLS']",Representation and design of heterogeneous components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/819064dc-0e6f-4a2b-9032-23b4c5dc4dee/download,,"Recent advances in rapid prototyping techniques enable the fabrication of
components whose composition can be controlled and varied in any desired fashion. This
presents design engineers with the opportunity and the challenge to design heterogeneous
components that optimize some design objective or can. provide certain functionality.
However, there are no well-established techniques for representing heterogeneous
components or design tools to arrive at the appropriate col11positiondistribution. A shape
and composition model based on iso-parametric interpolation functions.is. presented that
can be used in conjunction with non-linear programming algorithms to automatically
compute optimal composition distribution.",,,,,,
"['Alonso, Matthew Paul', 'Malone, Evan', 'Moon, Francis C.', 'Lipson, Hod']",2021-09-29T20:08:11Z,2021-09-29T20:08:11Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88208', 'http://dx.doi.org/10.26153/tsw/15149']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['telegraph', 'solid freeform fabrication', 'electromagnet', 'electromechanical', 'deposition', 'rapid prototyping', 'magnetic', 'assembly']",Reprinting the Telegraph: Replicating the Vail Register using Multi-Materials 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8685fe8a-d5f2-4f6a-bf15-0ef9ed9747ca/download,University of Texas at Austin,"Solid Freeform Fabrication is a family of manufacturing processes that create three-dimensional objects by depositing material, layer-by-layer. Traditionally, this technology has
been used to fabricate passive parts, but recently it has been used for producing active
components such as batteries and soft-polymer actuators. In this paper we demonstrate the ability
of this process to fabricate a complete, active electromechanical system. Using only SFF
processes, we reproduced the 1844 Vail register - a landmark in digital communications history.
With the techniques developed in this research, a range of solenoid devices can be fabricated and
embedded into freeform fabricated devices. This could enable the realization of novel and
otherwise difficult to manufacture electromechanical designs.",,,,,,
"['Liou, F.W.', 'Choi, J.', 'Landers, R.G.', 'Janardhan, V.', 'Balakrishnan, S.N.', 'Agarwal, S.']",2019-10-09T16:27:40Z,2019-10-09T16:27:40Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76157', 'http://dx.doi.org/10.26153/tsw/3246']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Hybrid,Research and Development of a Hybrid Rapid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ce4c0026-dcc9-4064-a4bf-8ff28a7f5832/download,,"This paper presents the research and development of a hybrid rapid manufacturing process being
developed at the University of Missouri-Rolla. This process includes a laser deposition and a 5-
axis CNC milling system. By combining laser deposition and machining processes, the resulting
hybrid process can provide greater build capability and better accuracy and surface finish. The
hybrid process can build some features that are difficult to build in using a purely deposition
processes. The issues and related approaches in the research and development of the hybrid
deposition-machining process, including laser deposition process, system design and integration,
process planning, and sensor selection and control, are discussed.","This research was supported by the National Science Foundation Grant Number DMI9871185, Missouri Research Board, and a grant from the Missouri Department of Economic
Development through the MRTC grant.",,,,,
"['Fahad, M.', 'Gilbert, M.', 'Dickens, P.']",2021-09-30T13:30:17Z,2021-09-30T13:30:17Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88237', 'http://dx.doi.org/10.26153/tsw/15178']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['support material', 'jetting', 'caprolactam', 'pluronic F-127', 'Rapid Manufacturing', 'Fourier Transform Infrared Spectroscopy', 'Polarization Microscopy']",Research into a Novel Support Material for Jetting Based RM Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/32dcf99c-9e54-4790-a64a-5d3947d1e6b7/download,University of Texas at Austin,"Jetting of caprolactam is a new Rapid Manufacturing process currently in the early phases of
research at Loughborough University. Support material is required to successfully build a
part using this method. This work is therefore, aimed at finding a suitable support material for
jetting of caprolactam. Pluronic F-127 with a non aqueous solvent was investigated using
different experimental techniques such as heating and cooling between 25 to 1500C, Fourier
Transform Infrared Spectroscopy and Polarization Microscopy and the possibility of use of
these systems as a support material is discussed. The results suggested that when Pluronic F-127 in ethylene glycol is heated, it does not form a gel at concentrations lower than 25%
(w/w) whereas at 25%, a gel state was observed near 500C. All concentrations studied formed
a white wax like solid upon cooling due to a changed conformational structure of PEO
chains. Although, a gel/solid state was not observed at high temperatures, these compositions
can provide a possible support material for a low temperature (i.e. 250C) build environment.",,,,,,
"['Ader, C.', 'Brosemer, M.', 'Freyer, C.', 'Fricke, H.', 'Hennigs, D.', 'Klocke, F.', 'Kühne, V.', 'Meiners, W.', 'Over, C.', 'Pleteit, H.', 'Stührmann, S.', 'Wirth, I.', 'Wirtz, T.', 'Wissenbach, K.']",2019-12-05T17:12:42Z,2019-12-05T17:12:42Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78649', 'http://dx.doi.org/10.26153/tsw/5705']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Fraunhofer,Research on Layer Manufacturing Techniques at Fraunhofer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5da94ad5-eca2-4987-a3e7-e408fc7525bf/download,,"Within the German Fraunhofer-Gesellschaft, the Fraunhofer Alliance Rapid Prototyping
 unites the competences of 12 institutes in the field of solid freeform fabrication. Covered
 competences are virtual and computer-aided product planning methods and techniques, the
 development and integration of materials and processes for different industrial sectors. This
 paper presents actual research results on layer manufacturing within the Fraunhofer-
 Gesellschaft based on examples from Fraunhofer ILT »Laser Melting - Direct
 manufacturing of metal parts with unique properties«, Fraunhofer IFAM »ecoMold - A
 novel concept to produce molds for plastic injection molding and pressure die casting« and
 Fraunhofer IPT »Quick manufacture, repair and modification of steel molds using
 Controlled Metal Build Up (CMB)«.",,,,,,
"['Zhang, Haiou', 'Jian, Hu', 'Wang, Guilan', 'Qi, He', 'Xie, Yang']",2021-10-13T20:28:39Z,2021-10-13T20:28:39Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88778', 'http://dx.doi.org/10.26153/tsw/15712']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['medium carbon steel parts', 'carbon steel parts', 'Hybrid Deposition and Micro Rolling', 'freeform arc deposition', 'microstructure', 'mechanical properties']",Research on Microstructure and Properties of Medium Carbon Steel Parts Manufactured by HDMR Technology,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ef7e647-89a2-461c-9433-683dd5edb1ad/download,University of Texas at Austin,"A new study on manufacturing medium carbon steel parts by HDMR (Hybrid Deposition and Micro
Rolling) technology was carried out, and the microstructures and mechanical properties obtained by HDMR
process and freeform arc deposition process respectively were tested and compared in this paper. The
experiment results show that: compared with the freeform arc deposition process, the grain size number
obtained by HDMR process increased from 3.0 to 9.0；the tensile strength and yield strength were increased
by 37.1%, 68.6%，in contrast to the investment casting, increased by 65.4% and 107.7%; compared with the
forging, the tensile strength and yield strength were increased by 12.9% and 31.4% respectively. Finally, a
medium carbon 45 steel aeronautical part difficult to overlay was manufactured successfully by HDMR
technology, thus a new efficient way for additive manufacturing of hard-shaping metal parts at high-quality
with low-cost was provided.",,,,,,
"['Kigure, T.', 'Yamauchi, Y.', 'Niino, T.']",2021-11-16T15:11:38Z,2021-11-16T15:11:38Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90308', 'http://dx.doi.org/10.26153/tsw/17229']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['working curve', 'depth of fusion', 'process parameter', 'part thickness', 'incident energy', 'low-temperature laser sintering', 'laser sintering']",Research on Relationship between Depth of Fusion and Process Parameters in Low-Temperature Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d1349862-4d1c-4cb7-850b-f1122e2be846/download,University of Texas at Austin,"Model of low-temperature laser sintering, in which part warpage during process is prevented
by anchoring of parts instead of high-temperature preheating, is discussed. Low-temperature
laser sintering process allows powder bed temperature to be lower than those in normal laser
sintering process which suppresses parts warpage by preheating powder bed above its
recrystallization temperature.
When we introduce a new process or material, many experimental examinations are required
to decide adequate building conditions. To reduce this process, theoretical process modeling
and simulations are carried out. In stereolithography, relationship between laser irradiance and
cure depth is known as “working curve,” and used for fundamental equation for this technology.
On the other hand, many theoretical models for laser sintering have been introduced, and most
of them are thermal models dealing with heat transfer in powder bed. Contrarily, there are few
reports concerning measurement and calculation of fusion depth though fusion depth can be
obtained easily by experiment and working curve is a useful to determination of building
parameters.
In this study, working curve which represents relationship between part thickness obtained by
monolayer scan and incident energy was investigated. As a result of normalizing the power by
the minimum power that can melt the surface of the powder bed, all the plots lay on the same
single line. This line, namely master curve, is unique for each powder and useful to finding
various parameters.",,,,,,
"['Seetharaman, Sankaranarayanan', 'Krishnan, Manickavasagam', 'Goh Chung Wen, Francis', 'Ahmed Khan, Niaz', 'Ng Ka Lai, Gary']",2021-10-26T19:59:54Z,2021-10-26T19:59:54Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89570,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'nickel superalloys', 'powder metallurgy', 'microstructure', 'mechanical properties', 'surface finish']",Research Updates on the Additive Manufacturing of Nickel Based Superalloys,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4821b9ea-dc4f-40f3-8052-8d7b2139b840/download,University of Texas at Austin,"Over the last decade, additive manufacturing technology has consistently evolved as a
sophisticated rapid manufacturing tool that allows direct fabrication of an end-usable part
without extensive tooling. The methodology of layer-by-layer fabrication demonstrates the novel
prospects of fabricating complex and multifunctional components and the aerospace and
automotive industries have been quite successful in adopting various additive technologies for
the use in jet engines, power plants and reactor vessels. This article will systematically review
the properties of nickel-based superalloys using different additive manufacturing methods. In the
first section, the types of additive manufacturing methods are briefly introduced. The properties
of Ni superalloy powders and the characterization methods are then discussed. The mechanical
properties displayed by additively manufactured Ni superalloys are presented and discussed
based on the influence of different processing and post-processing variables.",,,,,,
"['Hernandez, A.J.', 'Garcia, D.', 'Watanabe, K.I.', 'Gradl, P.R.', 'Wheeler, K.', 'Hafiychuk, Halyna', 'Wicker, R.B.', 'Medina, F.']",2024-03-27T15:56:53Z,2024-03-27T15:56:53Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124494', 'https://doi.org/10.26153/tsw/51102']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['DED', 'residual stress', 'deformation', 'overhangs', 'simulation']",RESIDUAL STRESS AND DEFORMATION ANALYSIS OF INCONEL 718 ACROSS VARYING OVERHANGS IN LASER POWDER BLOWN DIRECTED ENERGY DEPOSITION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9c8b976c-7f3c-4f4f-8e7d-38c7953c1185/download,University of Texas at Austin,"Any metal that is subjected to rapid heat and cooling will undergo the development of
residual stresses. As they experience intense temperature fluctuations, this will consequently alter
the way the material will behave. This issue proves to be of great concern within additive
manufacturing. That said, the presence of temperature fluctuations is more prominent in Directed
energy deposition (DED), whereas other methods of manufacturing are more prominent in the
pre- or post- printing process. This in turn means the deformation, as well as the redistribution of
the residual stresses within pieces, are subject to variance by several process parameters set
during a print. By using the Inconel 718 alloy feedstock in RPMI’s Laser Powder Directed
Energy Deposition (LP-DED) printer, a series of coupons with four different overhang angles
and laser power outputs will determine how these changes thermo-mechanically affect the prints
through the use of FEA simulations and scans.",,,,,,
"['Ong, Raymond', 'Beuth, Jack', 'Griffith, Michelle']",2019-09-23T15:40:17Z,2019-09-23T15:40:17Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75940', 'http://dx.doi.org/10.26153/tsw/3039']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Deposition,Residual Stress Control Issues for Thermal Deposition of Polymers in SFF Processes 209,Conference paper,https://repositories.lib.utexas.edu//bitstreams/62324b41-722c-4473-ad91-7d54c6f2a6c5/download,,"Controlling residual stress-induced warping and other tolerance losses is important for accurately creating parts by solid freeform fabrication (SFF). In this paper, results are presented from warping experiments on plate-shaped acrylonitrile butadiene styrene (ABS) specimensmcreated by an extrusion process used in Shape Deposition Manufacturing (SDM). Experimental results are compared to predictions from both one- and two-dimensional types of residual stress models. In addition to SDM, methods and results from this study are applicable to a number of other solid freeform fabrication processes involving extrusion of polymers or polymer slurries. Results from polymer extrusion are compared with those from existing work on thermal deposition of metals. Unlike metals, polymer deposition shows essentially no stress reduction due to preheating by the deposition process. Due to a greater number of deposited rows, directionality of warping is also greater than in metals. Polymer deposition experiments show that a preheat temperature near the glass transition temperature is needed for essentially no warping. Comparison of predicted and measured curvatures show that a simple 1-D thermomechanical model does not predict warping magnitudes well, but does provide insight into trends in warping as a function of preheat temperature. The effects of successive material
deposition are substantial in this process and a 2-D model that includes the effects of successively deposited rows can provide much more accurate curvature predictions.","The authors gratefully acknowledge financial support from the Gintic Institute of Manufacturing Technology and from the National Science Foundation, under grant DMI9700320. A software grant from SDRC allowed use of their software for finite element pre- and
post- processing.",,,,,
"['Wang, Xiaoqing', 'Chou, Kevin']",2021-10-21T19:37:07Z,2021-10-21T19:37:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89431,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Ti-6Al-4V', 'residual stress', 'Vickers indentation', 'microindentation', 'electron beam additive manufacturing']",Residual Stress in Metal Parts Produced by Powder-Bed Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/afc66ee3-147b-4c4b-b7fa-3f94923855a3/download,University of Texas at Austin,"In this study, residual stresses from the electron beam additive manufacturing (EBAM) and
selective laser melting (SLM) processes, due to repeated thermal cycles, were investigated.
Residual stresses play a crucial role in part performance, and thus, it is critical to evaluate the
process-induced residual stresses in AM parts. Ti-6Al-4V and Inconel 718 parts produced by
EBAM and SLM, respectively, were studied in residual stresses using the methodology established
by Carlsson et al., a mechanical instrumented indentation technique, which is based on the
experimental correlation between the indentation characteristic and the residual stress. The results
show that the Ti-6Al-4V EBAM parts have a compressive residual stress in both Z-plane and X-plane, while the Inconel 718 SLM parts show a tensile stress and a compressive stress in the Z-plane and X-plane, respectively. Besides, the Ti-6Al-4V parts have lower absolute value of
residual stress than the Inconel 718 parts. Moreover, the Vickers hardness values of the parts built
using SLM and EBAM are comparable to the literature data.",,,,,,
"['Yadroitsava, I.', 'Yadroitsev, I.']",2021-10-20T21:18:13Z,2021-10-20T21:18:13Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89363,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Direct Metal Laser Sintering', 'residual stress', 'metals']",Residual Stress in Metal Specimens Produced by Direct Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6724af47-327a-46d1-8afb-a9bef53d3240/download,University of Texas at Austin,"Direct Metal Laser Sintering (DMLS) has great potential in additive manufacturing
because it allows the production of full-density complex parts with the desired inner structure and
surface morphology. High temperature gradients, as a result of the locally concentrated energy
input, lead to residual stresses, crack formation and part deformations during processing or after
separation from the supports and the substrate. In this study, an X-ray diffraction technique and
numerical simulation were used for investigation of the residual stress in DMLS samples
fabricated from stainless steel 316L and Ti6Al4V alloy. Conclusions regarding directions and
values of stresses in DMLS objects are given.",,,,,,
"['Andurkar, Mohanish', 'Suzuki, Toshikazu', 'Omori, Masanao', 'Prorok, Bart', 'Gahl, John', 'Thompson, Scott']",2021-12-06T22:59:09Z,2021-12-06T22:59:09Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90707', 'http://dx.doi.org/10.26153/tsw/17626']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['FWHM', 'selective laser melting', 'microhardness', 'nickel superalloy', 'additive manufacturing']",Residual Stress Measurements via X-ray Diffraction Cos α Method on Various Heat-Treated Inconel 625 Specimens Fabricated via Laser-Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbab31b9-f41e-41ec-8cc1-3c649a69b249/download,University of Texas at Austin,"The residual stress and hardness of Inconel 625 fabricated using Laser Powder Bed
Fusion (L-PBF) were experimentally investigated. As-built Inconel 625 samples were
subjected to three different heat-treatment temperatures of 700℃, 900℃, 1050℃ for one
hour. Effects of these three-stress relieving heat treatment temperatures on the nature and value
of residual stress were studied. Residual stress measurements were recorded using a portable
X-ray system. The system calculated residual stress using the cos α method. The Full Width
Half Maximum (FWHM) of diffraction peaks in all samples were measured. The results
indicate that tensile residual stress was present on the surface of as-built L-PBF sample and
compressive residual stress on the surface of heat-treated samples due to stress relief. Debye-Scherrer (D-S) ring positions were measured using the cos α method and compared with a
reference wrought Inconel 625 ring position. Vickers microhardness and residual stress were
found to be positively correlated.",,,,,,
"['Martina, Filomeno', 'Roy, Matthew', 'Colegrove, Paul', 'Williams, Stewart W.']",2021-10-12T20:21:23Z,2021-10-12T20:21:23Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88732', 'http://dx.doi.org/10.26153/tsw/15666']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['wire + arc additive manufacturing', 'residual stress', 'high-pressure interpass rolling', 'high-pressure rolling', 'Ti-6Al-4V', 'aerospace']",Residual Stress Reduction in High Pressure Interpass Rolled Wire+Arc Additive Manufacturing Ti-6Al-4V Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/541f9720-e395-4cb6-acc0-ed5f0b95d855/download,University of Texas at Austin,"Wire+arc additive manufacturing (WAAM) components are characterised by high residual
stress due to the many consecutive deposition passes. Residual stress results in distortion once
the part is unclamped. High-pressure rolling was investigated as a way to address this issue in
Ti–6Al–4V linear parts. Rolling loads of 50 kN and 75 kN were investigated. Residual stress measurements, performed with the contour method, showed rolling was successful in reducing residual
stress substantially, especially at the interface between the part and the baseplate. High-pressure interpass rolling is likely to facilitate the implementation of WAAM for the manufacture of structural
aerospace components.",,,,,,
"['Nickel, A.', 'Barnett, D.', 'Link, G.', 'Prinz, F.']",2019-03-12T16:51:35Z,2019-03-12T16:51:35Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73602', 'http://dx.doi.org/10.26153/tsw/744']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Layered Manufacturing', 'Residual stresses']",Residual Stresses in Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83c1c396-7340-45b6-98b6-4f548109eedc/download,,"Layered Manufacturing processes accumulate residual stresses during materialbuildup. These stresses may cause part warping and layer delamination. This paper presents
work done on investigating residual stress accumulation andp(i,rt distortion of Layered
Manufactured artifacts. A simple analyticaLmodel was developed and used to determine how the number of layers and the layer thickness influences part warping. Resllits
show that thin layers produce lower part deflection as compared with depositing fewer
and thicker layers. In addition to the analytical work, a finite element model wasdeveloped and used to illvestigate the deposition pattern's influence on. the part deflection.
Finite element model and corresponding experimental analysis showed that the geometry of the deposition pattern significantly affects the resulting part distortion. This
finite element model was also used to investigate an inter-layer surface defect,. known
as the Christmas Thee Step, that is associated with Shape Deposition Manufacturing.
Results indicate that the features of this defect are influenced only by the material
deposited close. to the part·surface and the particular material deposited. The step is
not affected by the deposition pattern.",,,,,,
"['Mercelis, Peter', 'Kruth, Jean-Pierre']",2020-02-20T20:24:09Z,2020-02-20T20:24:09Z,8/24/05,Mechanical Engineering,,https://hdl.handle.net/2152/80049,eng,2005 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Residual Stresses in Selective Laser Sintering and Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/26460874-3788-4112-9545-4e79cfc6eabe/download,,,,,,,,
"['Yerazunis, W.', 'Weiss, A.', 'Radyjowski, P.', 'Cottrell, R.']",2023-04-03T17:51:20Z,2023-04-03T17:51:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117732', 'http://dx.doi.org/10.26153/tsw/44611']",eng,2022 International Solid Freeform Fabrication Symposium,Open,resin,Resin Development for On-Orbit Fabrication of Spacecraft Structures by Direct Solar Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/70b9d92d-03ea-4d95-af68-dd2e570b1790/download,,"One of the paradoxes of spacecraft design is that spacecraft are destined to operate in orbit
where maneuvering thruster firings produce stresses below 0.01 G, but the spacecraft must be
strong enough (and heavy enough) to survive the roughly 10 G’s of linear acceleration and 50
G’s of vibration in a rocket launch. In this paper, we follow on previous work to develop and
test an alternative: the post-launch freeform additive manufacture of a major communications
satellite structural element in UV cured resin, using solar UV to trigger polymerization. Here
we develop the chemistry of a UV curable liquid resin that not only has a very low (below our
chamber limit of 0.2 kPa) vapor pressure post-degassing, but also is not dependent on oxygen
presence to activate the thermal inhibitors that prevent premature polymerization. In tests, we
successfully freeform 3D printed a small (60 mm) parabolic dish at chamber limit pressure
using simulated solar UV flooding the chamber.",,,,,,
"['Ahsan, Nazmul', 'Habib, Ahasan', 'Khoda, Bashir']",2021-10-18T22:48:25Z,2021-10-18T22:48:25Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89281,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'build direction', 'fabrication', 'resource utilization']",Resource Based Build Direction in Additive Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bdb9fccd-16f7-4d7f-bdab-8a1aaab0317b/download,University of Texas at Austin,"Three dimensional free-form geometric shapes can be built by putting layers upon layer in a
predefined direction via Additive Manufacturing (AM) processes. The fabrication processes
require computational as well as physical resources and can vary not only upon the product but its
process plan. Overly simplified process plan may expedite the pre-fabrication techniques, but may
create difficulty during fabrication of those slices. For an example, slices with concavity or discrete
contour plurality may introduce deposition discontinuity, over deposition, and higher build time
during the fabrication. These issues demand more resources there by affecting the part quality and
fabrication cost. In this work, we focus upon the build direction of AM process plan to address the
fabrication and resource utilization. First, a set of uniform build direction is identified and the
object is discretized using a set of critical points considering the object concavity along the build
direction. Cutting planes are generated and the object is discretized into strips and each strip is
analyzed for contour plurality and the build directions are quantified through the allocation of
importance factors. The optimal build direction thus found will result in lowest possible fabrication
complexity. The proposed methodology is implemented and presented with a sample example in
this paper.",,,,,,
"['Tepper, C.', 'Utsch, J.', 'Zarges, J.', 'Weigold, M.']",2024-03-26T23:24:23Z,2024-03-26T23:24:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124449', 'https://doi.org/10.26153/tsw/51057']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['resource efficiency', 'hybrid-additive manufacturing', 'DED', 'robot']",Resource Efficiency of the Robot-Based Hybrid Additive Manufacturing Chain,Conference paper,https://repositories.lib.utexas.edu//bitstreams/46ff820b-a74b-42b0-8d13-21d72fafe8c7/download,University of Texas at Austin,"Combining additive and subtractive metal processes to a hybrid additive manufacturing chain
not only enables the production of parts with application-oriented design but also leads to
increased resource efficiency especially when combined in an industrial robotic cell.
Compared to parts manufactured through subtractive processes from full material the hybrid
additive manufacturing chain is considered to be resource efficient due to reduced material
consumption. However, the energy consumption of the hybrid additive process is considered
higher because of the use of laser for the additive process.
It is assumed that the decreased material consumption outweighs the higher energy
consumption regarding the resource efficiency but until now it is not investigated. Therefore,
in this paper the resource consumption of the robot-based hybrid additive manufacturing chain
including the wire based direct energy deposition process and the milling process is analysed
through measurements during experiments and compared to subtractive processes using the
carbon footprint as a reference.",,,,,,
"['Nandi, Indrajit', 'Ahmad, Nabeel', 'Shamsaei, Nima', 'Shao, Shuai']",2023-01-26T15:41:05Z,2023-01-26T15:41:05Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117320', 'http://dx.doi.org/10.26153/tsw/44201']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Laser powder bed fusion', 'Crystal plasticity finite element  simulation', 'Tensile fracture']",Revealing Texture Induced Abnormal Tensile Deformation Behavior in Additively Manufactured Haynes 282 Using Crystal Plasticity Simulations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4e4bc1c-8733-4941-9122-ce9cda048adb/download,,"A ductile fracture typically features a dimpled surface appearance because of micro-void 
coalescence and a circular cup-and-cone morphology. Tensile fracture surfaces of additively 
manufactured Haynes 282, a nickel-base superalloy, in this work exhibit an elliptical shape – an aberration 
to classic fracture surface. Both microstructural characterization and fractography were performed using 
scanning electron microscopy (SEM) on the tensile deformed surfaces to assess the fracture behavior. To 
gain better mechanistic insights into the governing factors of this elliptical shape fracture, crystal plasticity 
finite element (CPFE) simulations were performed using the experimentally calibrated material 
parameters. Uniaxial tensile loading simulations were carried out on a polycrystalline aggregate where the 
initial texture was varied to the CPFE simulation to emulate the experimental microstructure. The 
mechanical response and shape of the fracture surface obtained from the simulations were compared with 
the experimental tensile deformed surface to illustrate the texture dependent deformation inhomogeneity.",,,,,,
"['Rhyne, Breanna J.', 'Post, Brian K.', 'Chesser, Phillip', 'Roschli, Alex', 'Love, Lonnie J.']",2021-11-08T21:10:49Z,2021-11-08T21:10:49Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90042', 'http://dx.doi.org/10.26153/tsw/16963']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'reverse engineering', 'transhumeral prosthetic design', 'prosthetics']",Reverse Engineering a Transhumeral Prosthetic Design for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77af531d-8176-4397-860b-c44c47f73bec/download,University of Texas at Austin,"The customization and time savings additive manufacturing (AM) offers has been applied
to construct prosthetics. However, prosthetics produced using AM rarely resemble the original
appendage they are intended to replace. This report details the engineering of a transhumeral
prosthetic design for AM. A 3D scan of a subject’s existing arm and computer-aided design (CAD)
were used to create a mirrored prosthetic, which appeared aesthetically like the existing arm. The
process and complexities of integrating mechanical components for basic actuation into a patient-custom prosthetic are discussed. A simple demonstration of the process is provided. The same
methodology can be applied to more intricate prosthetics. This work aims to inspire subsequent
research into well-functioning, custom prosthetics that can be generated relatively quickly through
3D scanning and AM.",,,,,,
"['Rosen, David W.', 'Jeong, Namin']",2021-10-06T21:09:11Z,2021-10-06T21:09:11Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88444', 'http://dx.doi.org/10.26153/tsw/15381']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['image processing methods', 'microstructure models', 'CAD modeling', 'reverse engineering']",Reverse Engineering of Materials Using Image Processing Methods for CAD-Material Integration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a734700c-d379-482b-a725-549e0935332c/download,University of Texas at Austin,"Integration of material composition, microstructure, and mechanical properties with geometry
information enables many product development activities, including design, analysis, and
manufacturing. In this paper, we investigate the application of image processing methods for
constructing models of material microstructure. These microstructure models can be integrated
into CAD models to enable the utilization of material process-structure-property relationships
during CAD modeling. Engineering design is enabled by integration of computational materials
design methods with these relationships. Using 2D images and 3D voxel datasets, the image
processing methods can be used to find microstructure features, such as grain boundaries or
particle or fiber reinforcements, by finding edges and extracting features from those edges. This
paper will focus on three different image processing methods, which will be applied to
microstructure images of materials fabricated by additive manufacturing.",,,,,,
"['Jeong, Namin', 'Rosen, David W.']",2021-10-11T21:24:56Z,2021-10-11T21:24:56Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88648', 'http://dx.doi.org/10.26153/tsw/15582']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['reverse engineering', 'CAD systems', 'linear microstructure features', 'surfacelet based methods', 'additive manufacturing', 'microstructure features', 'material integration']",Reverse Engineering of Materials Using Surfacelet-Based Methods for CAD-Material Integration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83161e12-a640-4382-aa44-99f54290b1d9/download,University of Texas at Austin,"To integrate material information into CAD systems, geometric features of material
microstructure must be recognized and represented, which is the focus of this paper. Linear
microstructure features, such as fibers or grain boundaries, can be found computationally from
microstructure images using surfacelet based methods, which include the Radon or Radon-like
transform followed by a wavelet transform. By finding peaks in the transform results, linear
features can be recognized and characterized by length, orientation, and position. The challenge
is that often a feature will be imprecisely represented in the transformed parameter space. In this
paper, we demonstrate surfacelet-based methods to recognize microstructure features in parts
fabricated by additive manufacturing. We will provide an explicit mathematical method to
recognize and to quantify linear geometric features from an image.",,,,,,
"['Christensen, Jon', 'Bandyopadhyay, Amit']",2019-02-22T20:00:58Z,2019-02-22T20:00:58Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73469', 'http://dx.doi.org/10.26153/tsw/619']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CCD camera', 'CAD']",Reverse Engineering of Polymeric Solid Models Using Refractive Index Matching (RIM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba869d00-c127-4b9a-80cc-e8106e0a0e73/download,,"Reverse engineering (RE) techniques allows the creation of 3-D CAD files from a solid
model. The benefits of reverse engineering are not >new. to the industrial design and
manufacturing<arena though wide spread applications are yet to be seen. A novel approach is
used to reverse engineer polymeric parts with its internal features in aJow. cOst, non-destructive
manner. Solids created from polymers with anindex of refraction matching thatof an immersion
liquid are reverSe engineered using a CCD .calllera. The images are then used to create digital
solid models from a physical··model. Design·and development of this novel ilow costtool for
reverse engineering ofpolymeric solid models is described in this paper.",,,,,,
"['Steinberg, Ben', 'Razdan, Anshuman', 'Farin, Gerald']",2019-02-20T17:45:13Z,2019-02-20T17:45:13Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73457', 'http://dx.doi.org/10.26153/tsw/609']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'BSpline']",Reverse Engineering Trimmed NURB Surfaces From Laser Scanned Data,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a8491c4c-9c3b-4d64-907a-af712389f91b/download,,"A common reverse engineering problem is to convert several hundred thousand points
collected from the surface of an object via a digitizing process, into a coherent geometric
model that is easily transferred to a CAD software such as a solid modeler for either design
improvement or manufacturing and analysis. These data are very dense and make data-set
manipulation difficult and tedious. Many commercial solutions exist but involve time
consuming interaction to go from points to surface meshes such as BSplines or NURBS (Non
Uniform Rational BSplines). Our approach differs from current industry practice in that we
produce a mesh with little or no interaction from the user. The user can produce degree 2 and
higher BSpline surfaces and can choose the degree and number ofsegments as parameters to
the system. The BSpline surface is both compact and curvature continuous. The former
property reduces the large storage overhead, and the later implies a smooth can be created
from noisy data. In addition, the nature ofthe BSpline allows one to easily and smoothly alter
the surface, making re-engineering extremely feasible. The BSpline surface is created using
the principle ofhigher orders least squares with smoothing functions at the edges. Both linear
and cylindrical data sets are handled using an automated parameterization method. Also,
because ofthe BSpline's continuous nature, a multiresolutional-triangulated mesh can quickly
be produced. This last fact means that an STL file is simple to generate. STL files can also be
easily used as input to the system.",,,,,,
"['Buchele, S. F.', 'Ellingson, W. A.']",2018-12-07T15:49:28Z,2018-12-07T15:49:28Z,1997,Mechanical Engineering,doi:10.15781/T21G0JF4K,http://hdl.handle.net/2152/71438,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Solid modeling', 'CAD']",Reverse Engineering: Algebraic Boundary Representations to Constructive Solid Geometry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7612437-6279-4ba0-a7e3-77cb0c90b341/download,,"Recent advances in reverse engineering have focused on recovering a boundary
representation (b-rep) of an object, often for integration with rapid prototyping. This
boundary representation may be a 3-D point cloud, a triangulation of points, or piecewise
algebraic or parametric surfaces. This paper presents work in progress to develop an
algorithm to extend the current state of the art in reverse engineering of mechanical parts.
This algorithm will take algebraic surface representations as input and will produce a
constructive solid geometry (CSG) description that uses solid primitives such as
rectangular block, pyramid, sphere, cylinder, and cone. The proposed algorithm will
automatically generate a CSG solid model of a part given its algebraic b-rep, thus
allowing direct input into a CAD system and subsequent CSG model generation.",,,,,,
"['Griffin, Alair', 'McMillin, Scott', 'Griffin, Curtis', 'Knox, Dr. Charles']",2018-12-07T15:59:38Z,2018-12-07T15:59:38Z,1997,Mechanical Engineering,doi:10.15781/T2WP9TS91,http://hdl.handle.net/2152/71439,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['3D model', 'magnetic resonance']",Reverse Engineering: Practical Considerations for Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9671f2d-7e09-434e-b5dc-017abc0a2544/download,,"It is now possible to generate threedimensional
(3D) solid models of extremely
complicated systems from which full plastic
replicas can be generated using a variety of
rapid prototyping technologies. The cycle
time has been reduced to several hours, where
it previously took months to produce a comparable
prototype. The process of taking a
design into the 3D environment, whether
UNIX-or PC-based, is getting easier and fairly
straightforward.The design engineer interested in producing
a 3D model from unique data sets such
as computer tomography (CT) or magnetic
resonance (MR) image data is particularly
concerned with time, cost, accuracy, and conversion
problems. This paper presents an approach that Lone Peak Engineering, Inc. (LPE) has used that allows
them to successfully handle CT and MR data for reverse engineering (RE).",,,,,,
"['Flood, Aaron', 'Liou, Frank']",2021-11-03T20:13:21Z,2021-11-03T20:13:21Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89920,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['methodology', 'simulation', 'validation', 'laser based metal additive manufacturing']",Review of AM Simulation Validation Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a144f24e-4567-4367-b030-5071f24e30cd/download,University of Texas at Austin,"Due to the complexity of Additive Manufacturing (AM), it can require many trial runs to
obtain processing parameters which produce a quality build. Because of this trial and error
process, the drive for simulations of AM has grown significantly. Simulations only become
useful to researchers if it can be shown that they are true representations of the physical process
being simulated. All simulations have different methods of validation to show that they are
an accurate representations of the process. This paper explores the various methodologies
for validation of laser based metal AM simulations, focusing mainly on the modeling of the
thermal processes and other characteristics derived from thermal history. It will identify and
explain the various validation techniques, specifically looking at the frequency of reported use
of each technique.",,,,,,
"['Crisp, Tyler G.', 'Weaver, Jason M.']",2021-12-07T18:17:34Z,2021-12-07T18:17:34Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90746', 'http://dx.doi.org/10.26153/tsw/17665']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['big area additive manufacturing', 'Oak Ridge National Laboratory', 'Cincinnati Inc', 'large area additive manufacturing', 'large format 3D printing', 'hybrid manufacturing', 'functionally graded material', 'composite additive manufacturing']",Review of Current Problems and Developments in Large Area Additive Manufacturing (LAAM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6dda843-df71-4745-b9bb-d02d610af14f/download,University of Texas at Austin,"Large Area Additive Manufacturing (LAAM), also known as Big Area Additive Manufacturing
(BAAM), is a screw extrusion, pellet-fed additive manufacturing technology. The large build
area, rapid build speed, and inexpensive pelletized feedstock of LAAM are major advantages
over conventional AM methods. LAAM has a large variety of applications in areas including
energy, automotive, aerospace, high volume production, and composite molds. However, LAAM
is not without its challenges. The largest challenges LAAM faces include mechanical properties,
uniformity and precision, and predictability of composite material properties. The goal of this
paper is to present current research regarding challenges in LAAM, methods of addressing those
challenges, developments, and applications, as well to highlight further research to be done.",,,,,,
"['Lorenz, K.A.', 'Jones, J.B.', 'Wimpenny, D.I.', 'Jackson, M.R.']",2021-10-19T17:59:48Z,2021-10-19T17:59:48Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89311,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Hybrid Manufacturing', 'Hybrid Manufacturing Systems', 'laser-based Additive Manufacturing', 'Computer Numerical Controlled', 'history']",A Review of Hybrid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/52a295cf-0b72-4b6f-9280-8bf99f89d239/download,University of Texas at Austin,"In recent years the combination of laser-based Additive Manufacturing and Computer
Numerical Controlled (CNC) machining has become increasingly popular, with several machine
tool manufacturers exhibiting products based on different machine tool configurations. This
technology, widely known as Hybrid Manufacturing, generally exploits Directed Energy
Deposition processes using powder feedstock that is fed into a melt pool created by a laser.
Although Directed Energy Deposition processes predate powder bed fusion Additive
Manufacturing (at least in terms of coating and repair applications), commercialization of Hybrid
Manufacturing systems is still very much in its infancy. However, they do offer clear advantages,
combining a high deposition rate together with the accuracy and surface finish associated with
machining. This paper presents the history of the development of Hybrid Manufacturing Systems
(HMS), dating back from work undertaken in the mid 1990s through to the present day. The
relative merits of different material deposition approaches are compared and some of the key
technical challenges which remain are highlighted and discussed.",,,,,,
"['Ruan, Jianzhong', 'Sparks, Todd E.', 'Fan, Zhiqiang', 'Stroble, Jacquelyn Kay', 'Panackal, Ajay', 'Liou, Frank']",2020-02-28T15:37:53Z,2020-02-28T15:37:53Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80112', 'http://dx.doi.org/10.26153/tsw/7133']",eng,2006 International Solid Freeform Fabrication Symposium,Open,selective laser sinstering,A Review of Layer Based Manufacturing Processes for Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/491b06d4-82c1-4ffb-aec1-e5be57982feb/download,,"The metal layered manufacturing processes have provided industries with a fast method
to build functional parts directly from CAD models. This paper compares current metal layered
manufacturing technologies from including powder based metal deposition, selective laser
sinstering (SLS), wire feed deposition etc. The characteristics of each process, including its
industrial applications, advantages/disadvantages, costs etc are discussed. In addition, the
comparison between each process in terms of build rate, suitable metal etc. is presented in this
paper.",,,,,,
"['Zhang, Hui', 'Guo, Yanling', 'Jiang, Kiayi', 'Bourell, David L.', 'Zhao, Dejin', 'Yu, Yueqiang', 'Wang, Puxuan', 'Li, Zhipeng']",2021-10-27T22:22:25Z,2021-10-27T22:22:25Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89632,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['wood-plastic composites', 'selective laser sintering', 'historical review']",A Review of Selective Laser Sintering of Wood-Plastic Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cf50047a-8c5d-4b28-9698-f0fb769b9e6f/download,,"Eco-friendly wood-plastic composites were firstly proposed to be used as the raw
materials of rapid prototyping in 2002, and successfully applied in Selective Laser
Sintering (SLS) two years later. These composites were mixed by different kinds of
wood powder, plastic powder and other additives. Different from polymer, ceramics,
metals and their composites, wood-plastic composites are new types of sustainable
and low-price feedstock of SLS.
This paper presents the development of the research of wood-plastic composites
applied to SLS over the past decade. It contains the preparation and characterizations
of wood-plastic composites, the study of temperature fields and molecular dynamics
simulation of sintering wood-plastic composites, the effects of processing parameters
on the forming accuracy and mechanical properties of sintered parts, and the post-treating process of wood-plastic composite parts. At last, it introduces the application
fields of laser sintered wood-plastic composites parts.",,,,,,
"['Yasa, Evren', 'Ersoy, Kivilcim']",2021-11-10T21:36:54Z,2021-11-10T21:36:54Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90183', 'http://dx.doi.org/10.26153/tsw/17104']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'polymer matrix composites', 'layered manufacturing', 'carbon fiber reinforced polymers', 'rapid manufacturing']",A Review of the Additive Manufacturing of Fiber Reinforced Polymer Matrix Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/14c3e205-f1c1-4bde-9744-fdc6b67fc8b0/download,University of Texas at Austin,"Additive manufacturing (AM), also referred to as 3D printing, has gained popularity due
to the recent developments and market trends especially in the last decades. The main advantages
of AM are its capability of producing parts with high geometrical complexity at almost no added
cost, short lead times, weight reduction, less efforts for assembly and suitability for customization
as well as for low volume production or even single parts. Moreover, some applications may
need materials with unusual combinations of properties, which cannot be provided only by
metals, polymers or ceramics. For such applications, composite materials combining two or more
materials allow having the preferred properties combined in a single material. Thus, AM, which
can be defined as a process of adding materials to produce objects directly from its CAD model
in successive layers in contrast to subtractive processes, is gaining significance for critical
applications using composite materials. This paper thus presents a detailed review of AM of
polymers reinforced with chopped / continuous fibers and the influence of this reinforcement on
the mechanical performance of composite parts, mainly focusing on the Fused Deposition
Modelling (FDM) process. On one hand, the reviewed studies on the FDM of composites mainly
point out that that the mechanical performance is significantly enhanced in contrast to polymers
with no reinforcement. Yet, it is also evident that the mechanical performance of FDM
composites is highly dependent on the build direction and porosity. Thus, there is still a wide
range of gaps to be studied for replacing metallic components by AM composites.",,,,,,
"['Zeng, Kai', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-06T21:43:20Z,2021-10-06T21:43:20Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88453', 'http://dx.doi.org/10.26153/tsw/15390']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'selective laser melting', 'finite element modeling', 'thermal analysis']",A Review of Thermal Analysis Methods in Laser Sintering and Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e1e8e51-b86d-47be-a490-746775febdcd/download,University of Texas at Austin,"Thermal analysis of laser processes can be used to predict thermal stresses and
microstructures during processing and in a completed part. Thermal analysis is also the basis for
feedback control of laser processing parameters in manufacturing. A comprehensive literature
review of thermal analysis methods utilized in Laser Sintering (LS) has been undertaken. In
many studies, experimental methods were commonly used to detect and validate thermal
behavior during processing. Coupling of thermal experiments and FEM analyses were utilized in
many of the latter studies. Analytical solutions were often derived from the Rosenthal solution
and other established theories. In recent years, some temperature measuring systems have been
implemented to validate the simulation results. The main characteristics of LS temperature
distribution and effects of process parameters to temperature are also summarized and shown by
a case study.",,,,,,
"['Norris, Marshall', 'Fidan, Ismail', 'Allen, Michael']",2023-01-26T14:23:58Z,2023-01-26T14:23:58Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117305', 'http://dx.doi.org/10.26153/tsw/44186']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Extruded Material', '3D Printing', 'Powdered Metal', 'Rheology']",Rheological Characterization of Room Temperature Powder Metal Paste for Extruded Material Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ca5879cb-2155-4aa7-b502-be28433fded6/download,,"Powder metals have been used in Additive Manufacturing (AM) processes such as 
injection molding, extrusion, and slip casting for decades. Recent innovations in the Fused 
Filament Fabrication (FFF) have provided the opportunity to mix powder metals with a binding 
thermoplastic at elevated temperatures to create 3D components. This research attempts to define 
the rheological characteristics of paste materials used to produce 3D components at room 
temperature using powder metals that will provide the following three outcomes: material that will 
flow under low shear stress, green strength to provide structural support of material deposited on 
top and prevent deformation under gravitational load, and once cured to provide material 
properties that are comparable to those of materials produced by traditional means. The purpose 
of this research is to determine if powder metal components can be produced by FFF at room 
temperature while maximizing the powder metal composition in the mixture.",,,,,,
"['Ajinjeru, Christine', 'Kishore, Vidya', 'Liu, Peng', 'Hassen, Ahmed Arabi', 'Lindahl, John', 'Kunc, Vlastimil', 'Duty, Chad']",2021-11-02T18:09:23Z,2021-11-02T18:09:23Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89849,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['processing condition', 'high temperature polymers', 'thermoplastics', 'deposition system', 'extrusion-based additive manufacturing']",Rheological Evaluation of High Temperature Polymers to Identify Successful Extrusion Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/80c9244a-e875-49ef-b2e7-4f6cf167abef/download,University of Texas at Austin,"With the advancements in additive manufacturing (AM), several high temperature thermoplastics
are being explored as potential AM feedstocks. Some of these high-performance thermoplastics
include; polyetherimides (PEI), polyphenylsulfones (PPSU/F), poly (ether ketone ketone)s
(PEKK) and polyphenylene sulfide (PPS) as well as their reinforced composites. Most of these
advanced resins tend to be more expensive than commodity plastics such as acrylonitrile butadiene
styrene (ABS) and polylactic acid (PLA), and their processing parameters have not been
determined for most AM systems. This paper demonstrates a method for identifying the
appropriate processing conditions for extrusion-based AM deposition systems, in which a material
is forced through an orifice at a given flow rate. The pressure required to extrude a shear-thinning
thermoplastic at a given shear rate is calculated based on viscoelastic properties of the polymer
melt and compared against maximum system pressure to predict successful extrusion. An
evaluation of several candidate materials is presented on the Big Area Additive Manufacturing
extrusion-based platform.",,,,,,
"['Ramesh, Srikanthan', 'Gerdes, Sam', 'Lau, Sharon', 'Mostafavi, Azadeh', 'Kong, Zhenyu', 'Johnson, Blake N.', 'Tamayol, Ali', 'Rao, Prahalada', 'Rivero, Iris V.']",2021-11-09T20:35:48Z,2021-11-09T20:35:48Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90160', 'http://dx.doi.org/10.26153/tsw/17081']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['printability', 'muscle regeneration', 'in-situ monitoring', 'bioprinting', 'C2C12 myoblasts']","Rheological, In Situ Printability and Cell Viability Analysis of Hydrogels for Muscle Tissue Regeneration",Conference paper,https://repositories.lib.utexas.edu//bitstreams/ad3519f1-7469-4458-9805-be14e7a9c592/download,University of Texas at Austin,"Advancements in additive manufacturing have made it possible to fabricate biologically relevant
architectures from a wide variety of materials. Hydrogels have garnered increased attention for the
fabrication of muscle tissue engineering constructs due to their resemblance to living tissue and
ability to function as cell carriers. However, there is a lack of systematic approaches to screen
bioinks based on their inherent properties, such as rheology, printability and cell viability.
Furthermore, this study takes the critical first-step for connecting in-process sensor data with
construct quality by studying the influence of printing parameters. Alginate-chitosan hydrogels
were synthesized and subjected to a systematic rheological analysis. In situ print layer photography
was utilized to identify the optimum printing parameters and also characterize the fabricated three-dimensional structures. Additionally, the scaffolds were seeded with C2C12 mouse myoblasts to
test the suitability of the scaffolds for muscle tissue engineering. The results from the rheological
analysis and print layer photography led to the development of a set of optimum processing
conditions that produced a quality deposit while the cell viability tests indicated the suitability of
the hydrogel for muscle tissue engineering applications.",,,,,,
"['Xia, Bin', 'Krueger, Paul S.']",2021-11-18T17:45:15Z,2021-11-18T17:45:15Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90444', 'http://dx.doi.org/10.26153/tsw/17365']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['particulate composite', 'viscosity', 'rheology', 'particulate suspension', 'additive manufacturing', '3-D printing', 'capillary flow', 'jamming condition', 'volume fraction', 'particle size']",Rheology and Applications of Particulate Composites in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7bc74119-28bb-461a-827d-640b55171419/download,University of Texas at Austin,"To provide different functionalities such as electrical conductivity or magnetic
permeability, particulate composites have been utilized widely in additive manufacturing. These
types of materials are usually formulated with different functional particles and shear thinning
non-Newtonian fluids such as polymer melts and silicone. The materials are viscous non-Newtonian suspensions during formulation and printing, and their rheology is a key factor for the
processing. This paper will concentrate on suspensions with micron-sized particles, and discuss
the rheology and overall flow behavior in capillaries scaled appropriately for additive
manufacturing applications (around 1 mm ID). Micron size glass beads and shear thinning silicone
are used to demonstrate the impact of particle volume fraction on the shear thinning behavior. The
impact of particle and capillary size on viscosity and jamming conditions will be discussed.
Previous models based on Newtonian fluids and in free flowing conditions will also be reviewed
and compared.",,,,,,
"['Zhu, Cheng', 'Smay, James E.']",2021-09-30T19:39:59Z,2021-09-30T19:39:59Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88286', 'http://dx.doi.org/10.26153/tsw/15227']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['3D mesoscale structures', 'direct-write asssembly', 'colloidal gels', 'rheology', 'shear history', 'thixotropic rheological', 'concentrated colloidal gels', 'flow behavior']",Rheology and Flow Behavior of Concentrated Colloidal Gels for Direct-Write Assembly of 3D Mesoscale Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/976f50aa-d420-4b05-b275-89aa5f0079d8/download,University of Texas at Austin,"3D mesoscale structures with various patterns have been successfully fabricated by direct-write
assembly of concentrated colloidal gels. Geometric fidelity of these structures is very important
to functionality as devices and has been closely tied to gels microstructure dynamics, which
depends on the rheology and shear history. Here, Al2O3 gels were prepared and employed as
model materials. A thixotropic rheological model was developed to show the time dependent
behavior of gels structure during shear flow. The model accounts for structure formation and
attrition, each with a shear history dependent rate constant. The true wall stress was measured by
correcting the end effects and wall slip. The extrusion flow dynamics of the gel was simulated by
using CFD method to disclose the structure profiles of extrusion filaments and predict the
structure evolution of as-deposited filaments.",,,,,,
"['Crocket, R.S.', 'Calvert, P.D.']",2018-12-07T17:13:26Z,2018-12-07T17:13:26Z,1997,Mechanical Engineering,doi:10.15781/T2707X82M,http://hdl.handle.net/2152/71452,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['spreading bead', 'Deposition']",Rheology and Solid Freeform Fabrication: Modeling Material Flow in Deposition Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2b5a45e1-703f-4ce1-a1b0-c16cac79a1d7/download,,,,,,,,
"['Carton, Molly Aubrey', 'Nandi, Chandrakana', 'Anderson, Adam', 'Zhao, Haisen', 'Darulova, Eva', 'Grossman, Dan', 'Lipton, Jeffrey Ian', 'Schulz, Adriana', 'Tatlock, Zachary']",2021-12-06T23:41:46Z,2021-12-06T23:41:46Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90720', 'http://dx.doi.org/10.26153/tsw/17639']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['parallel printing', 'simultaneous extrusion', '3D printer', '3D printing', 'development', 'roadmap']",A Roadmap Towards Parallel Printing for Desktop 3D Printers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ef487e7-d4ce-4ea7-97ef-c3ef1e11666a/download,University of Texas at Austin,"3D printers with multiple extruders (or multi­headed printers) are common in the desktop fabrication community, but are primarily used for multi-­color or multi-­material printing, using only one
extruder at a time. What if these multi­headed desktop printers could also be used for simultaneous parallel printing? While this is a relatively unexplored direction, we argue that it deserves
further investigation: a flexible, robust, and affordable parallel printing ecosystem could significantly reduce fabrication time for many applications and further enhance the value of desktop rapid
prototyping.
We propose a research agenda to explore the development of a parallel printing pipeline, and
summarize our observations from a preliminary investigation of simultaneous extrusion. We hope
this vision will encourage and guide future research in developing hardware, firmware, and slicers
to facilitate parallel 3D printing.",,,,,,
"['Smay, James E.', 'Cesarano III, Joseph', 'Lin, Shawn Y.', 'Stuecker, John N.', 'Lewis, Jennifer A.']",2019-10-09T16:39:06Z,2019-10-09T16:39:06Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76162', 'http://dx.doi.org/10.26153/tsw/3251']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Photonic,Robocasting of Photonic Band Gap Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85410dc1-0e85-4ce0-8b31-a1ac000d6a3c/download,,,,,,,,
"['Stuecker, John N.', 'Cesarano III, Joseph', 'Smay, James E.']",2019-10-18T17:02:51Z,2019-10-18T17:02:51Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76262', 'http://dx.doi.org/10.26153/tsw/3351']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Filtration,Robocasting Periodic Lattices for Advanced Filtration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb74c9d7-f6bc-4ca3-a4f2-3fee4b1e9027/download,,"Ceramic filters used in the casting of molten metals are commonly created by slurry impregnation
of polymeric foams, yielding a fired ceramic foam structure. These foam structures have high part-to-part
standard deviation in flow rates (~25%) and have weak sections which can fragment into the melt. In
contrast, periodic lattice filters (PLF’s) made by robocasting have a cross-hatched face-centered-cubic
arrangement of rods.. As such, the robocast filters have high strength and may be easily tailored to offer a
specific internal pore structure to control the flow rate and pressure drop across the filters. Standard
deviation of flow rates among PLF’s are less than 1%. This paper describes the methodology of creating
PLF’s as possible foam filter replacements.",,,,,,
"['Khatua, Vivek', 'Gurumoorthy, B.', 'Ananthasuresh, G.K.']",2024-03-26T21:49:16Z,2024-03-26T21:49:16Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124426', 'https://doi.org/10.26153/tsw/51034']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['fiber-reinforced polymer composite', 'photopolymerization', 'additive manufacturing']",Robot-aided selective embedding of a spatially steered fiber in polymer composite parts made using vat photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e806ce32-99c3-4478-9720-a4346472d767/download,University of Texas at Austin,"Fiber-Reinforced Polymer Composite (FRPC) parts are predominantly laminates, shells, or
surfaces wound with 2+D fiber patterns even after the emergence of additive manufacturing.
Making FRPC parts with embedded continuous fibers in 3D is not reported previously even
though topology optimization demonstrates that such designs are optimal. Earlier attempts in
3D fiber reinforcement include making parts with channels into which fibers are inserted or coextruding fiber with resin. In this work, A Vat-Photopolymerization Machine, and a process for
concurrent embedding of spatially steered continuous fibers inside the matrix is developed. A
single continuous fiber was embedded spatially using a robot to gradually steer the fiber as the
part is built layer upon layer. An example of a fiber embedded along a helix in a cylindrical
matrix is included in this work. Furthermore, a hinge effect was demonstrated when a fiber was
embedded at a place that has substantial bending about the axis of the fiber.",,,,,,
"['Baier, Christian', 'Weigold, Matthias']",2021-11-16T16:34:31Z,2021-11-16T16:34:31Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90338', 'http://dx.doi.org/10.26153/tsw/17259']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['hybrid manufacturing', 'industrial robots', 'alloy 718', 'quality-loops', 'deep-drawing die']",Robot-Based Hybrid Manufacturing Process Chain,Conference paper,https://repositories.lib.utexas.edu//bitstreams/667ffb8a-28aa-4e07-8989-605e4ed8a9ba/download,University of Texas at Austin,"The combination of additive and subtractive processes using an industrial robot in a hybrid production
concept is an innovative approach in manufacturing technology. An improvement in the near net shape geometry
production processes is achieved by using a wire-based laser metal deposition process with the added benefit of
saving resources. Assisted by qualified CAM tools and an interposed laser line scanning, this process chain
enables production of tool and dies, especially for automotive industry and manufacturing of parts made of nickelbased alloys for aerospace industry. This expands the workpiece material application range for robot-based
milling. For the robot-machining processes, extended strategies in CAM path planning have been qualified
focusing on increased machining-process quality. The system technology and sub-processes have been integrated
into a robot-cell, enabling a hybrid part production process in a single workpiece clamping.",,,,,,
"['Förster, Julia', 'Binder, Maximilian', 'Schlick, Georg', 'Seidel, Christian', 'Schilp, Johannes']",2023-01-27T14:14:33Z,2023-01-27T14:14:33Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117336', 'http://dx.doi.org/10.26153/tsw/44217']",eng,2022 International Solid Freeform Fabrication Symposium,Open,powder bed fusion,Robot-guided Electrophotographic Powder Application System for Powder Bed Fusion of Metals by means of Laser Beam,Conference paper,https://repositories.lib.utexas.edu//bitstreams/975cb52f-299a-4afc-bfb2-adc6156d383c/download,,"Powder application remains amongst the core challenges in Powder bed based additive manufacturing. Current 
state of the art does hardly allow processing of powders with low flowability or the processing of multiple 
materials (multi-material) within one layer. In this paper, a powder application process based on 
electrophotography is presented to increase the flexibility of additive manufacturing processes using powder bed 
fusion of metals (PBF-LB/M) as specific reference. A novel conceptual design of an automated 6-axis robot-
controlled prototype for electrophotographic powder application in a machine environment are shown. 
Experiments demonstrate single- and multi-layer powder depositions for the PBF-LB/M typical powder CW106C 
(CuCrZr1). A first qualitative comparison of the powder application process in the ambient media in atmospheric 
conditions and in an argon inert gas atmosphere is performed. With the automated powder application, the general 
inclusion in the PBF-LB/M cycle for multi-layer deposition and melting can be demonstrated.",,,,,,
"['Solomon, E.', 'Yerazunis, W.S.']",2021-12-01T21:30:20Z,2021-12-01T21:30:20Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90620', 'http://dx.doi.org/10.26153/tsw/17539']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['SLA 3D printing', 'robotic grippers', 'grippers', 'mechanical metamaterials']",Robotic Applications of Mechanical Metamaterials Produced Using SLA 3D Printing: Cthulhu-Morphic Grippers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0f69666-1e47-4a17-8017-db001a21ab5b/download,University of Texas at Austin,"Presented in this paper is a 3D printed flexible robotic gripper which has three individual
independently actuated tentacles, each with two sections, and a combined 12 degrees of
freedom (DoF); produced through the creation of a mechanical metamaterial via SLA 3D
printing. This gripper was built to improve upon existing soft robotic technologies by creating
a highly versatile gripping device which can hold a wide variety of items. This gripper is
capable of the fine motor control necessary to hold a pen or a small screw, the gross motor
strength to hold a sledge hammer, and the grip span to hold a shop-vac air filter. Grip
strengths and failure modes for various gripping configurations are measured. With an axial
lift capacity well in excess of 100N, this gripper is strong enough to be useful in industrial
applications. Potential industrial uses include warehouse or assembly line bin-picking and
cobot operations.",,,,,,
"['Shahan, David', 'Fulcher, Ben', 'Seepersad, Carolyn Conner']",2021-10-05T15:08:14Z,2021-10-05T15:08:14Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88389', 'http://dx.doi.org/10.26153/tsw/15328']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'negative stiffness', 'vibration isolation', 'axially compressed beams']",Robust Design of Negative Stiffness Elements Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9b50dd8c-c240-41ab-bd69-32d212c0986d/download,University of Texas at Austin,"Constrained negative stiffness structures have been shown to possess desirable vibration
isolation properties because of their ability to provide low dynamic stiffness, resulting in low
transmissibility over a wide range of frequencies. In this research, selective laser sintering (SLS)
is an integral part of a model-design-build-test process for investigating the vibration isolation
capabilities of negative stiffness structures in the form of axially compressed beams. SLS
provides geometric design freedom and rapid fabrication capabilities for validating dynamic
models of structural behavior and guiding the design process toward iterative improvements.
SLS also introduces some geometric and dimensional variability that can significantly degrade
the performance of the structure. In this paper, an iterative model-design-build-test process for
negative stiffness structures is described and presented with an analysis of the impact of SLS-induced imperfections on the results.",,,,,,
"Chari, Jana K.",2018-05-03T18:14:43Z,2018-05-03T18:14:43Z,1993,Mechanical Engineering,doi:10.15781/T2BK1768V,http://hdl.handle.net/2152/65050,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['IGES', 'Non-Uniform Rational B-Splines', 'NURBS', 'CAD file']",Robust Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1a667fd0-3935-421d-8b77-0685b2edcb7a/download,,"This paper presents a new prototyping system consisting of a computer interface based
on IGES standard to represent and path plan objects with precise curve and surface definitions
and a laser-metal deposition process for the prototype fabrication. The advantage
of using the Non-Uniform Rational B-Splines (NURBS) data instead of the traditional triangular
data is that it requires fewer data conversions as most standard analytical shapes
(like lines, conics, circles, planes and quadratic surfaces) as well as free form curves and
surfaces are represented with one common underlying mathematical form. By addressing
this issue of improved data representation on the CAD file front-end and an improved
processing technique, this research will significantly impact the output of rapid prototyping
with functional parts of improved tolerance and surface finish capabilities. A detailed
description of the implementation of the computer interface on different hardware platforms
and an outline of the fabrication process are presented. We conclude that NURBS
interfacing technique is a robust mathematical technique and offers great potential for
precise rapid prototyping.",,,,,,
"['Wu, Sung-Heng', 'Joy, Ranjit', 'Tariq, Usman', 'Mahmood, Muhammad Arif', 'Liou, Frank']",2024-03-26T21:52:22Z,2024-03-26T21:52:22Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124427', 'https://doi.org/10.26153/tsw/51035']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['direct energy deposition', 'melt pool', 'thermal distribution', 'in-situ monitoring', 'digital twin development']",Role of In-situ Monitoring Technique for Digital Twin Development using Direct Energy Deposition: Melt Pool Dynamics and Thermal Distribution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2e7fa74-0629-4028-a1fc-76b440535aa1/download,University of Texas at Austin,"Direct energy deposition (DED) is a promising additive manufacturing technique that enables the fabrication
of complex structures with excellent mechanical properties. The quality of the final product depends on several
parameters, including melt pool dynamics and thermal distribution. For process monitoring and continuous
improvement of digital twins, in-situ monitoring allows real-time tracking of these parameters, providing valuable
data for process optimization. However, existing monitoring methods are limited in their accuracy due to
emissivity issues. To address this challenge, an in-house visible spectrum camera has been proposed for real-time
process monitoring via dual-wavelength technique. Based on the analyses, the area and thermal distribution inside
the melt pool can be estimated accurately. The data from the camera can be integrated into a digital twin’s
continuous improvement, providing efficiency, and reducing the manufacturing cost.",,,,,,
"['Allen, J.', 'Cheng, J.', 'Hu, X.', 'Splitter, D.A.', 'Gussev, M.', 'Shyam, A.']",2021-12-07T19:02:15Z,2021-12-07T19:02:15Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90758', 'http://dx.doi.org/10.26153/tsw/17677']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additively manufactured interpenetrating composites', 'AMPICs', '316L', 'stainless steel', 'A356']",The Role of Interface in Additively Manufactured Interpenetrating Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eecf9aa7-458d-443a-8194-e04a2a779fcd/download,University of Texas at Austin,"Additively Manufactured Interpenetrating Composites (AMIPCs) are a relatively new metal-metal
chain composite in development for use in high energy absorption systems. In this system,
reinforcing phase of additively manufactured continuous lattice configurations 316L austenitic
stainless-steel is in melt infiltrated with a matrix phase of A356 aluminum-silicon casting alloy.
Measurements and observations of this material system have shown that weakly bonded or
open/porous interface between the reinforcement and matrix phases exhibits dramatically different
mechanical properties of AMIPCs, which is not currently well understood. In this work, Finite
Element Models (FEM) are used to model the effects of interfaces between the composite phases.
Mechanical tensile tests measurements of various composite volume fractions and varying degrees
of casting infiltration are also examined and used to show consistency with the FEM results. The
outcome provides insight into material design criteria and performance predictions for new hybrid
material systems with exceptional damage tolerance.","This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725
with the US Department of Energy (DOE).",,,,,
"['Rangarajan, Sriram', 'Qi, Gang', 'Banyopadhyay, Amit', 'Dai, Cheng', 'W. Han, Joon', 'Bhargava, Parag', 'Wu, Suxing', 'Safar, Ahmad', 'Danforth, Stephen. C.']",2018-12-05T20:16:17Z,2018-12-05T20:16:17Z,1997,Mechanical Engineering,doi:10.15781/T2CV4CB90,http://hdl.handle.net/2152/71411,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'Printing/Inkjet Deposition']",The Role of Materials Processing Variables in the FDC Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/04e8c0dd-9fba-45d7-b0b0-b309d2d5371e/download,,"The Fused Deposition of Ceramics (FDC) is based on the commercially available
Fused Deposition Modeling (IDMTM) technique developed by Stratasys Inc. The FDC
process is being currently developed to make complex ceramic parts in an automated
fashion. Although the current focus is on making SisN4 parts, this technique has been
successfully used to make electroceramic (such as PZT) and metallic (such as stainless
steel) parts.
As feedstock for the IDC process, filaments loaded with 55 vol% GS-44 Si3N4 is
being used. For the filament to be used in the IDC process, it must possess a unique
combination of physical, rheological and mechanical properties. In this paper, we
investigate the role played by some of the process variables on these properties. Our current
processing sequence to make filaments is as follows - coating of powders with a surfactant,
compounding the ceramic and binder, extrusion into filaments and finally treatment of
filaments to achieve requisite properties. The study has resulted in improvements to the
quality of the filament which can be used for automated FDC. The effect of moisture,
agglomerates and filament aging on FDC will be discussed.",,,,,,
"['Hauser, C.', 'Lewis, D. M.', 'Morris, K. F.', 'Broadbent, P. J', 'Zhao, X.', 'Clare, A. T.', 'Dunschen, M.']",2020-03-11T15:38:48Z,2020-03-11T15:38:48Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80255', 'http://dx.doi.org/10.26153/tsw/7274']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Direct Light Projection', 'DLP']",Rotational 3D Printing of Sensor Devices using Reactive Ink Chemistries,Conference paper,https://repositories.lib.utexas.edu//bitstreams/84a13a4b-7917-4980-87c1-5cdd1dca1e23/download,,"This paper charts progress in three key areas of a project supported by both UK
government and UK industry to manufacture novel sensor devices using rotary 3D printing
technology and innovative ink chemistries; (1) the development of an STL file slicing algorithm
that returns constant Z height 2D contour data at a resolution that matches the given print head
setup, allowing digital images to be generated of the correct size without the need for scaling;
(2) the development of image transformation algorithms which allow images to be printed at
higher resolutions using tilted print heads and; (3) the formulation of multi part reaction inks
which combine and react on the substrate to form solid material layers with a finite thickness. A
Direct Light Projection (DLP) technique demonstrated the robustness of the slice data by
constructing fine detailed three dimensional test pieces which were comparable to identical parts
built in an identical way from slice data obtained using commercial software. Material systems
currently under investigation include plaster, stiff polyamides and epoxy polymers and
conductive metallic’s. Early experimental results show conductivities of silver approaching
1.42x105 Siemens/m.",,,,,,
"['Garrett, Alexis', 'Jaberi, Arian', 'Viotto, Auston', 'Yang, Ruiguo', 'Tamayol, Ali', 'Malshe, Ajay', 'Sealy, Michael P.']",2021-12-01T21:22:10Z,2021-12-01T21:22:10Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90617', 'http://dx.doi.org/10.26153/tsw/17536']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['edible', 'polymer', 'cellular agriculture', 'photolithography']",Rotational Digital Light Processing for Edible Scaffold Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5210ba99-4105-47e2-9c97-710bce5edffe/download,University of Texas at Austin,"A key hurdle to overcome in the development of alternative meat-based protein is the manipulation
of mechanical or mastic properties of the 3D scaffolds. These properties influence the mouth feel
of the product and must be tunable to achieve a variety of meat analogous textures. The goal of
this research was to investigate a printing technology hypothesized to enable textural adjustment
in alternative proteins. In pursuit of this goal, a novel digital light processing (DLP) printer with a
rotational collector plate was developed to enable radially cured layers with the ability to
incorporate multi-material composite structures. The purpose of this research was to quantify the
effect of cured layer orientation on the bulk mechanical properties of (gelatin methacryloyl)
GelMA scaffolds. In addition, current photocrosslinking systems do not emphasize the edibility of
the materials used in the process. Tartrazine, an edible photo-absorber, was investigated in its use
for improving print resolution during the crosslinking process.",,,,,,
"['Richter, B.', 'Blanke, N.', 'Werner, C.', 'Vollertsen, F.', 'Pfefferkorn, F.E.']",2021-11-16T16:23:03Z,2021-11-16T16:23:03Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90333', 'http://dx.doi.org/10.26153/tsw/17254']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser', 'polishing', 'additive manufacturing', 'surface analysis', 'identification', 'topography']",Roughness Parameters for Classification of As-Built and Laser Post-Processed Additive Manufactured Surfaces,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc9ade07-4515-4a3d-a3e9-8e4b395b474e/download,University of Texas at Austin,"One of the challenges facing the industrial adoption of additively manufactured parts is the
surface roughness on the as-built part. The surface roughness of parts is frequently characterized
by metrics specified by international standards organizations. However, these standards list many
surface metrics that can make it unclear which to use to best describe the surface. In this work, the
ability of the various surface metrics to successfully classify the as-built and post-processed
surfaces is studied using linear classification models. Laser polishing via remelting and manual
grinding are the post-processing techniques used to smooth the as-built surface. The ability of the
linear classifier to successfully categorize the various surfaces is demonstrated, and the various
surface metrics are ranked according to the strength of their individual ability to classify the
surfaces. This work promotes the method as a potential way to autonomously classify as-built and
laser polished surfaces.",,,,,,
"['Wang, Wanlong', 'Conley, James G.', 'Stoll, Henry W.', 'Jiang, Rui']",2019-03-06T18:07:30Z,2019-03-06T18:07:30Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73560', 'http://dx.doi.org/10.26153/tsw/702']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['rapid tooling', 'process selection']",RP Process Selection for Rapid Tooling in Sand Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2838b9a2-4ace-499d-b19d-b4ff1f175d7f/download,,"The significant cycle-time improvements and geometrical capabilities of solid freeform
fabrication systems have led to applications in sand casting industry for design verification and
tooling. The time and cost effective deployment of rapid tooling processes using rapid
prototyping technology has thus becoming an emerging area to be studied. To make full use of
the advantages of rapid prototyping processes, the factors influencing the tooling approach must
be identified and understood. This understanding is then used to develop a decision-making
structure for RP process selection for rapid tooling in sand casting. In this manuscript we review
our work in evaluating and building a framework for tooling process selection for sand casting",,,,,,
"['Eschey, C.', 'Feldmann, S.', 'Zaeh, M.F.']",2021-10-04T21:55:05Z,2021-10-04T21:55:05Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88362', 'http://dx.doi.org/10.26153/tsw/15301']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Additive Layer Manufacturing', 'rule-based FFD', 'Free-Form Deformation']",Rule-Based Free-Form Deformation for Additive Layer Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c9c971fb-5dca-4ad8-9b06-d0a4de946398/download,University of Texas at Austin,"Additive Layer Manufacturing (ALM) provides manufacturing of nearly arbitrary geometries
flexibly and economically. The part properties, which are reachable by state-of-the-art systems,
are able to fulfill the customer requirements in terms of series and spare part production.
Nevertheless, there still arise problems prohibiting the prevalent application of those techniques.
The presented approach focuses on a rule-based Free-Form Deformation (FFD) for ALM. The
machine is characterized by a set of rules, which is identified through observable properties
extracted from precedent building processes. Adapting and applying the FFD algorithm, a pre-deformation of desired geometries based on exclusively geometric rules is achieved. Using an
exclusively geometric deformation technique, CAD data is deformed before manufacturing to
provide higher part quality by considering the unique characteristic of a machine.",,,,,,
"['Schlienger, E', 'Griffith, M.', 'Oliver, M.', 'Romero, J.A.', 'Smugeresky, J.']",2019-02-19T20:09:05Z,2019-02-19T20:09:05Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73443', 'http://dx.doi.org/10.26153/tsw/595']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LENS', 'structure']",Sacrificial Materials for the Fabrication of Complex Geometries with LENS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/41dccd2d-7a7c-4803-9638-5eec7489a81f/download,,,,,,,,
"['Bzymek, Zbigniew M.', 'Ferreira, David', 'Marcus, Harris', 'Shaw, Leon L.']",2019-03-12T16:02:18Z,2019-03-12T16:02:18Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73592', 'http://dx.doi.org/10.26153/tsw/734']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SALVI', 'SALD']",SALD and SALVI Virtual Laboratory,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4fe0d0d8-8e81-4e49-a20c-72c546ae8303/download,,"This paper describes efforts to apply virtual manufacturing techniques to produce machine
parts using Solid Freeform Fabrication (SFF). In particular, the work was done to develop a
Virtual SFF Laboratory for the Selective Area Laser Deposition (S~D) and Selective Area Las~r
Deposition Vapor Infl1tration (SALDVI) for the manufacture of machine parts and research on theIr
characteristics, as well as for research on development of SAW and SALDVI technologies. It
was the goal of the authors to supply the user with a tool to design a part, develop its three
dimensional model, render it and observe its shape and dimensions. Except for research,
laboratory is intended to be used for teaching principles of design and manufacturing of machine
parts, as well as for delnonstrating SAW and SALVI processes to visitors. The Virtual Laboratory
was developed on Silicon Graphics workstations. The Virtual Laboratory can create a multi-media,
stereoscopic presentations of the SAW and SALVI processes in the Solid Freeform Fabrication
Laboratory at the Institute of Material Science (IMS) at the University of Connecticut. The
presentations can also be distributed through the Internet.",,,,,,
"['Crocker, James E.', 'Wei, Haoyan', 'Shaw, Leon L.', 'Marcus, Harris L.']",2019-10-09T16:34:37Z,2019-10-09T16:34:37Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76160', 'http://dx.doi.org/10.26153/tsw/3249']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Ceramic,SALDVI of SiC into Metal and Ceramic Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d19f66b2-f033-4c7e-b953-0a2bf5c8a8b7/download,,"Selective Area Laser Deposition Vapor Infiltration (SALDVI) is the SFF technique using
gas phase precursors to locally infiltrate a powder bed into a desired shape. Experiments were
performed with a CO2 laser and the silicon carbide forming gas precursor Si(CH3)4. This paper
will report on the microstructural aspects of SiC into a variety of metal and ceramic powders
including Mo, SiC, ZrO2, and WC.","The authors acknowledge the support for this research by the Office of Naval Research
(grant #N00014-95-1-0978).",,,,,
"['Crocker, James E.', 'Jakubenas, Kevin J.', 'Harrison, Shay', 'Shaw, Leon L.', 'Marcus, Harris L.']",2018-12-05T20:45:21Z,2018-12-05T20:45:21Z,1997,Mechanical Engineering,doi:10.15781/T2GM8283H,http://hdl.handle.net/2152/71419,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SALDVI', 'laser beam']",SALDVI Optimization for the Tetramethylsilane - Silicon Carbide System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/31ca7457-4f38-4473-be14-7dda033ce02a/download,,"Selective Area Laser Deposition Vapor Infiltration (SALDVI) ofsilicon carbide powder
infiltrated with silicon carbide deposited from tetramethylsilane (TMS) was studied. The effects
of deposition time, temperature, and gas precursor pressure are discussed. The discussion
centers on the efforts to properly balance these parameters to produce multi-layered shapes with
structural integrity, particularly for use as the matrix material for shapes containing embedded
devices. This includes optimizing scan speed, deposition temperature, and gas pressure to
maximize infiltration to increase density and layer to layer bonding, and minimize excessive
deposition to maintain critical dimensions. Initial powder properties are also optimized to
minimize bulk motion in the powder bed during deposition, which was observed and identified
as a mechanism that reduces inter-layer bonding.",,,,,,
"['Kantareddy, S.N.R.', 'Roh, B.M.', 'Simpson, T.W.', 'Joshi, S.', 'Dickman, C.', 'Lehtihet, E.A.']",2021-11-01T21:23:09Z,2021-11-01T21:23:09Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89758,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['large-scale lattice structures', 'metallic', 'metallic lattice structures', 'lattice structures', 'real-world example', 'oil', 'gas', 'additive manufacturing']",Saving Weight with Metallic Lattice Structures: Design Challenges with a Real-World Example,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66829db6-684a-4e27-8ca5-1b91c692d5f1/download,University of Texas at Austin,"Lattice structures are structurally efficient yet complex designs that enable high
stiffness and reduce weight. While lattice structures are traditionally difficult to
manufacture in metal with conventional fabrication processes, AM is a viable solution to
manufacture such complex geometries to achieve lightweight designs. However, there is
relatively little information available in the literature about designing large-scale lattice
structures, particularly concerning computer-aided design tools, structural analysis, and
post-processing for functional metallic components. In this study, we investigate and
discuss these aspects in the context of a real-world problem for an oil and gas application.
The lattice structure is designed and fabricated with IN 718 powder using an EOS M280
laser-based powder bed fusion system. A weight reduction of 42.4% is achieved while
obtaining the desired mechanical performance. Results and challenges, particularly with
the design workflow, are discussed along with future research directions.",,,,,,
"['Chu, W.S.', 'Jung, B.S.', 'Ahn, H.']",2021-09-29T20:33:41Z,2021-09-29T20:33:41Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88217', 'http://dx.doi.org/10.26153/tsw/15158']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['drug delivery system', 'layer manufacturing', 'replication', 'direct deposition', 'scaffold fabrication', 'nano composite deposition system']",Scaffold Fabrication for Drug Delivery System Using Layered Manufacturing Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9bdb90f3-ee4c-48db-b710-14ba92983d2c/download,University of Texas at Austin,"To fabricate functional shape of drug delivery system (DDS), various processes are used. In
this research, based on layered manufacturing, two different processes of 1) replication and 2)
direct deposition were used to fabricate scaffold type implantable DDS. For replication process,
hot embossing process for fabrication of patterned layers and bonding for construction of three-dimensional shape were used. As a direct deposition process, nano composite deposition system
(NCDS) was used. Various scaffolds were fabricated with different filament size, pore size, and
shape. It is observed that the scaffold type of implantable DDS is more stable than non-porous
DDS through the in vivo test.",,,,,,
"['Angrish, A.', 'Singh, S.', 'Shen, X.', 'Lee, Y.S.', 'Cohen, P.', 'Starly, B.']",2021-10-28T15:33:04Z,2021-10-28T15:33:04Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89663,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['cybermanufacturing', 'process monitoring', 'NoSQL databases', 'networked additive manufacturing', 'mongoDB']",Scalable Linking of Slice Layer Information with Process Monitoring Data in Additive Manufacturing Machines,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13443a0a-505b-4837-a2e2-7e137cb58288/download,University of Texas at Austin,"In smart connected factories, manufacturing machines are capable of generating vast amounts of
process data generated internally from within its control systems or from sensors coupled with the
process. This streaming data must be stored and queried to perform data analytics or closed loop
control to improve manufacturing processes. Currently, structured data schemas are ineffective in
handling image and time-series data generated from additive manufacturing machines. In this
paper, we propose an unstructured data schema through NoSQL document oriented database
systems as an effective and scalable approach to capturing and storing real-time streaming data for
process monitoring. In addition, we present an approach to linking in real-time, slice layer
information and tag it with process related sensor data for performing fast, scalable queries either
in real-time or post-fabrication. We have demonstrated our approach with two classes of additive
manufacturing machines – Fused Deposition Modeling and Electron Beam Melting Systems from
Makerbot and ARCAM respectively.",,,,,,
"['Birnbaum, Andrew J.', 'Beuth, Jack L.', 'Sears, James W.']",2020-02-12T15:39:23Z,2020-02-12T15:39:23Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79941', 'http://dx.doi.org/10.26153/tsw/6967']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Manufacturing Processes,Scaling Effects in Laser-Based Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6b091d2b-6b12-4275-acc8-e9a37ab66007/download,,,,,,,,
"['Chung, Haseung', 'Das, Suman']",2019-10-24T17:30:09Z,2019-10-24T17:30:09Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77401', 'http://dx.doi.org/10.26153/tsw/4490']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Resolidification,Scaling Laws for Melting and Resolidification in Direct Selective Laser Sintering of Metals,Conference paper,https://repositories.lib.utexas.edu//bitstreams/959a0d09-b0ea-4b82-95f2-701e84c87a10/download,,"We present a one-dimensional model describing the physical mechanisms of heat transfer,
melting and resolidification taking place during and after the interaction of a laser beam with a
semi-infinite metal surface. The physical model describing this situation is based on the classical
Stefan problem with appropriately chosen boundary conditions to reflect direct selective laser
sintering of metals. A numerical model based on the finite volume method is developed to
perform computations for different beam diameters, scan speeds, substrate temperatures and
power input profiles. From the results of these computations, we derive relations for time to
initiate melting, time to reach maximum melting depth, and total melt-resolidification time. The
surface temperature histories for three different power input profiles are compared with
approximate closed form solutions.",,,,,,
"['Bermudez, Diego', 'Terrazas, Cesar A.', 'Morton, Phillip', 'Wicker, Ryan']",2021-11-01T23:04:23Z,2021-11-01T23:04:23Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89794,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['scanning strategies', 'scanning', 'microstructure', 'Ti-6Al-4V', 'electron beam melting']",Scanning Strategies in Electron Beam Melting to Influence Microstructure Development,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0fc79706-a72f-4c10-97a2-710c048bdce1/download,University of Texas at Austin,"Recent advances with the use of electron beam melting (EBM) additive manufacturing
(AM) have indicated the ability to control the resultant microstructure based on control of the
processing parameters. An Arcam A2 EBM system was utilized to control the size of the
microstructure for Ti-6Al-4V components. The methodology employed allowed to refine the
microstructure at selected regions of a part while maintaining a more typical acicular α+β
microstructure in the rest of the components. This process was achieved by partitioning the layer
data into two files that enabled different scanning conditions during fabrication. The first scan
consisted of hatching of the component geometry (circle with dimensions of 15mm in diameter)
excluding a center circle with dimensions of 1mm in diameter. Following the first scan, a pointwise melting for the center circle was completed. The strategy generated a finer structure in the
center circle in comparison with the more regular sized microstructure in the rest of the build.
Components built were sectioned and prepared into metallographic specimens that were observed
through optical microscopy. The micrographs were used to measure the length and width of alpha
laths.",,,,,,
"['Wang, Zhaogui', 'Smith, Douglas E.']",2021-11-15T20:44:52Z,2021-11-15T20:44:52Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90265', 'http://dx.doi.org/10.26153/tsw/17186']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['screw swirling', 'fiber orientation', 'elastic properties', 'large-scale additive manufacturing', 'LSAM']",Screw Swirling Effects on Fiber Orientation Distribution in Large-Scale Polymer Composite Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f635b33a-9cd4-4220-8b82-ac460da48df8/download,University of Texas at Austin,"Large-Scale Additive Manufacturing (LSAM) polymer deposition employs a single screw
extruder to melt and deliver the pelletized feedstock resulting in significantly higher flow rates as
compared to conventional filament-extrusion AM processes. Single screw swirling motion in the
melt flow during processing generates a unique pattern of flow-induced fiber alignment when
fiber-filled polymer feedstock is processed. This paper investigates the effect of the single screw
swirling motion on the fiber orientation and predicted elastic properties of a printed extrudate. A
finite element extruder nozzle flow is created, where the extruder screw tip, the extrusion nozzle,
and a short section of free extrudate compose the melt flow domain. The IRD-RSC fiber orientation
diffusion model is applied to capture the slow orientation kinetics of short fibers in the
concentrated fiber suspension. The results indicate that the swirling motion of the flow has a direct
effect on predicted fiber orientation distribution and the associated averaged elastic properties in
the extruded composite bead.",,,,,,
"['Wood, Nathaniel', 'Hoelzle, David J.']",2021-11-16T16:09:44Z,2021-11-16T16:09:44Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90328', 'http://dx.doi.org/10.26153/tsw/17249']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['temperature fields', 'closed-loop state', 'efficacy', 'powder bed fusion']",'Seeing' the Temperature Inside the Part During the Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/da1f2d28-c49b-4094-ae92-e26a99b14d57/download,University of Texas at Austin,"Powder Bed Fusion (PBF) is a type of Additive Manufacturing (AM) technology that builds
parts in a layer-by-layer fashion out of a bed of metal powder via the selective melting action of a
laser or electron beam heat source. The technology has become widespread, however the demand
is growing for closed loop process monitoring and control in PBF systems to replace the open
loop architectures that exist today. This paper demonstrates the simulated efficacy of applying
closed-loop state estimation to the problem of monitoring temperature fields within parts during
the PBF build process. A simplified LTI model of PBF thermal physics with the properties of
stability, controllability and observability is presented. An Ensemble Kalman Filter is applied
to the model. The accuracy of this filters’ predictions are assessed in simulation studies of the
temperature evolution of various test parts when subjected to simulated laser heat input. The
significant result of this study is that the filter supplied predictions that were about 2.5x more
accurate than the open loop model in these simulation studies.",,,,,,
"['Morgan, Jacob P.', 'Morgan, John P. Jr.', 'Natale, Donald J.', 'Smith, Robert W.M.', 'Mitchell, Wesley F.', 'Dunbar, Alexander J.', 'Reutzel, Edward W.']",2021-11-03T22:32:53Z,2021-11-03T22:32:53Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89951,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['process monitoring', 'high resolution imaging', 'sychronization', 'post-build 3D computed tomography', 'computed tomography', 'powder bed fusion additive manufacturing']","Selection and Installation of High Resolution Imaging to Monitor the PBFAM Process, and Synchronization to Post-Build 3D Computed Tomography",Conference paper,https://repositories.lib.utexas.edu//bitstreams/0bd26817-21dc-4580-b896-6d41a23ccfc1/download,University of Texas at Austin,"Industrial applications of PBFAM continue to expand, and there is a growing interest in
the use of sensors to monitor the build process. Sensor data collected during the build process
provides insight into process physics and may also lead to a reduction in overall fabrication time
and cost by offering an alternative to extensive post-build nondestructive inspection for quality
control. Ultimately, sensor data may serve as feedback for real-time control systems that
automatically repair flaws before they are buried by subsequent layers.
In this work, high resolution images are explored as a means of monitoring the PBFAM
build process inside a 3D Systems ProX320. Key design considerations for camera selection and
integration are discussed. Methods and algorithms are developed to calibrate and map layer-wise
imagery to laser scan vectors. Images are stacked and exported to standardized 3D data formats to
enable easy inspection and comparison to post-build 3D computed tomography (CT) volumes.",,,,,,
"['Harris, Russ', 'Hopkinson, Neil', 'Dickens, Phill', 'Hague, Richard']",2019-09-23T17:08:07Z,2019-09-23T17:08:07Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75975', 'http://dx.doi.org/10.26153/tsw/3074']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Mould,The Selection of Mould Design Variables in Direct Stereolithography Injection Mould Tooling 478,Conference paper,https://repositories.lib.utexas.edu//bitstreams/86a6e782-15ae-4039-9d14-3cb54b0b62b9/download,,"The introduction of rapid prototyping has allowed engineers and designers to generate physical models of required parts very early on in the design and development phase. Further to this the use of stereolithography (SL) cavities as a rapid tooling method has allowed plastic prototype parts to be produced in their most common production manner; by injection moulding. The process is best suited to small production runs where the high costs of conventionally machined tooling is prohibitive. One of the major drawbacks of the SL injection moulding process is the susceptibility of the tools to premature failure. SL tools may break under the force exerted by part ejection when the friction between a moulding and a core is greater than the tensile strength of the core resulting in tensile failure. Very few justified recommendations exist concerning the choice of mould design variables that can lower the part ejection force experienced and reduce the risk of SL tool failure. This research investigates the ejection forces resulting from injection moulding polypropylene (PP) and acrylonitrile-butadiene-styrene (ABS) parts from SL tools which are identical in all respects except for their build layer thickness and incorporated draft angles. This work attempts to
identify appropriate evidence for recommendations with respect to these design variables and SL injection moulding. The results show that adjustment of draft angle results in a change of part ejection force as a reasonably linear relationship. An adjustment of the build layer thickness results in a change in part ejection force as a more non-linear relationship. The adjustment of build layer thickness had a greater effect on ejection force than the adjustment of draft angle. In both cases greater ejection forces were experienced by ABS parts as compared to PP parts. The results also show that the surface roughness of all tools remains unchanged after moulding a number of parts in both polymers.",,,,,,
"['Thissell, W.Richards', 'Zong, Guisheng', 'Tompkins, James', 'Birmingham, Britton R.', 'Marcus, Harris L.']",2018-04-17T18:48:44Z,2018-04-17T18:48:44Z,1991,Mechanical Engineering,doi:10.15781/T26Q1T08B,http://hdl.handle.net/2152/64352,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SALD', 'pyrolytic', 'photolytic']",Selective Area Laser Deposition - A Method of Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bce07d25-a366-4687-bc49-6e5373f6c1c4/download,,,,,,,,
"['Weiss, Clayton M.', 'Marcus, Harris L.']",2021-10-05T18:41:35Z,2021-10-05T18:41:35Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88403', 'http://dx.doi.org/10.26153/tsw/15342']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['ceramic joining', 'ceramic manufacturing', 'selective area laser deposition', 'silicon nitride']",Selective Area Laser Deposition for Silicon Nitride Joining,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4d23463e-4ce7-4954-a017-437676ec2429/download,University of Texas at Austin,"Ceramic joining is a difficult step in ceramic manufacturing. Joining ceramics, in a
chemically homogeneous way, can be performed through the repurposing of an additive
manufacturing technique involving local deposition of ceramics from the gas phase. Selective
area laser deposition uses a gas phase precursor environment and a laser heat source to form
ceramic deposits. These deposits can be positioned with great spatial resolution; as such, it is
possible to form the joint with the ceramic material to create a monolithic structure. Silicon
nitride is explored as a joining material for silicon nitride work pieces. The experimental
conditions are described and the joint formation is characterized.",,,,,,
"['Birmingham, B.R.', 'Zong, G.', 'Tompkins, J.V.', 'Marcus, H.L.']",2018-04-17T19:42:38Z,2018-04-17T19:42:38Z,1991,Mechanical Engineering,doi:10.15781/T2K06XJ0Z,http://hdl.handle.net/2152/64358,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SALD', 'SFF']",Selective Area Laser Deposition from Acetylene and Methane to Increase Deposition Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5ed717c5-3520-47eb-8982-7a664ec4ae4d/download,,"Selective area laser deposition (SALD) has been used to deposit carbon from
acetylene. Working at the relatively high pressures required to produce high deposition
rates can result in explosive uncontrollable growth. Pr~vious computational modeling
indicates that the energy released from the exothermic decomposition of acetylene to
carbon may be responsible for this behaviour[l]. Since methane decomposes
endothermically to form carbon over certain temperatures, it is possible that methane
addition to the process may help control the deposition rate. The purpose of this paper
is to describe SALD experiments that were performed using various partial pressures of
acetylene and methane as precursor in order to determine if combining an endothermic
and an exothermic reaction effects the control of the SALD process.",,,,,,
"['Jakubenas, Kevin', 'Marcus, H.L.']",2018-11-08T15:13:16Z,2018-11-08T15:13:16Z,1995,Mechanical Engineering,doi:10.15781/T27D2QT0K,http://hdl.handle.net/2152/69885,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SALD', 'deposition experiments', 'vapor deposition']",Selective Area Laser Deposition from Titanium Tetrachloride,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4aed227-2475-4a49-ab38-c7360b0298fc/download,,"Selective Area Laser Deposition (SALD) has demonstrated the ability to deposit
controlled shapes of silicon carbide and silicon nitride by using a laser beam to decompose a
precursor gas. The goal of the work here is to include titanium among the list of SALD
materials, although this goal has not yet been reached. This paper describes the selection of
precursors and the results of some SALD experiments using the first precursor explored,
titanium tetrachloride. The results of precursor gas mixture, pressure, and laser power on
deposition composition and rates are discussed.",,,,,,
"['Weiss, Clayton', 'Marcus, Harris']",2021-10-11T21:12:42Z,2021-10-11T21:12:42Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88643', 'http://dx.doi.org/10.26153/tsw/15577']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective area laser deposition', 'monolithic joint', 'aluminum oxide']",Selective Area Laser Deposition Joining of Aluminum Oxide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2e7e1f6-321b-4507-9271-7f0a5c0993b9/download,University of Texas at Austin,"Selective area laser deposition (SALD) is a chemical vapor deposition technique used to
deposit ceramic material. The technique allows localized deposition in the area of the laser spot;
complex depositions can be achieved through the use of a computer control program. It is
possible to free form fabricate arbitrary shapes. In particular by defining the space between two
work pieces as the envelope for deposition, it is possible to form a monolithic joint. The use of a
trimethylaluminum and diethyl ether precursor system is explored as a means of depositing
aluminum oxide. The alumina is used as joint fill material for alumina SALD joining.",,,,,,
"Tompkins, James V.",2018-05-03T19:57:09Z,2018-05-03T19:57:09Z,1993,Mechanical Engineering,doi:10.15781/T23X84367,http://hdl.handle.net/2152/65075,,1993 International Solid Freeform Fabrication Symposium,Open,"['selective area laser deposition', 'SALD', 'Center for Materials Science and Engineering']",Selective Area Laser Deposition of Silicon Carbide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4bbe84c1-3bd9-4590-8b80-96a9c650bfa7/download,,,,,,,,
"['Schwerdtfeger, Jan', 'Heinl, Peter', 'Singer, Robert F.', 'Körner, Carolin']",2021-09-29T18:06:51Z,2021-09-29T18:06:51Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88204', 'http://dx.doi.org/10.26153/tsw/15145']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['auxetic cellular structures', 'titanium alloys', 'Selective Electron Beam Melting']",Selective Electron Beam Melting: A new Way to Auxetic Cellular Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/69e42821-2ca1-45c9-ad2c-f41d26843203/download,,"This paper is concerned with the build up and characterisation of well defined auxetic
structures from Titanium alloys through Selective Electron Beam Melting (SEBM).The
negative Poisson’s ratio of auxetic structures make them interesting candidates for a wide
range of applications (e.g. joining of dissimilar materials). Up to date auxetic cellulars have
mainly been produced through volumetric compression of conventional foams. However, by
using SEBM we are able to produce structures of any geometry in a well defined manner.
This opens an almost limitless field for new cellular auxetics and the tuning of their properties.
In the following we will introduce a simple self designed auxetic structure and show first
results for the mechanical characterisation of that structure.",,,,,,
"['Baumers, M.', 'Tuck, C.', 'Hague, R.']",2021-10-19T18:02:13Z,2021-10-19T18:02:13Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89312,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Heat Sintering', 'Laser Sintering', 'deposition rate', 'energy consumption', 'cost']","Selective Heat Sintering Versus Laser Sintering: Comparison of Deposition Rate, Process Energy Consumption and Cost Performance",Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc86ad6e-89c0-45d4-b551-8ddabb0aa426/download,University of Texas at Austin,"The Selective Heat Sintering (SHS) process has become available as a low cost
alternative to Laser Sintering (LS) for the additive deposition of polymer objects. While both
processes belong to the powder bed fusion variant of Additive Manufacturing (AM) technology,
their operating principles vary significantly: SHS employs a thermal print head to selectively
fuse material powder, whereas the LS approach utilizes a laser beam coupled with a
galvanometer. Based on a series of build experiments, this research compares these technology
variants along three dimensions of process efficiency: deposition rate (measured in cm³/h),
specific process energy consumption (MJ/kg) and specific cost ($/cm³). To ensure that both
platforms are assessed under the condition of efficient technology utilization, an automatic
build volume packing algorithm is employed to configure a subset of build experiments.
Beyond reporting absolute and relative process performance, this paper additionally
investigates how sensitive the compared processes are to a variation in the degree of capacity
utilization and discusses the application of different levels of indirect cost in models of low cost
AM.",,,,,,
"['Wimpenny, David Ian', 'Banerjee, Soumya']",2020-03-05T20:30:58Z,2020-03-05T20:30:58Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80161', 'http://dx.doi.org/10.26153/tsw/7182']",eng,2006 International Solid Freeform Fabrication Symposium,Open,rapid prototyping,Selective Infrared Sintering of Polymeric Powders using Radiant IR Heating & Ink Jet Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4df8c43b-9dd8-4289-9ed0-e5279168da3a/download,,"Established methods of rapid prototyping by sintering polymeric powders have
predominantly focused on the use of lasers to selectively heat the polymeric particles
together to form fused layers. Although effective, this route requires the laser to draw in
the entire cross section of the slice and this limits the speed of the process, particularly for
the production of thick walled parts. The use of IR radiant lamps to fuse an entire layer
simultaneously has been explored by several groups and is now the basis of at least one
commercially available process (Speed Part). An alternative route, developed by the
Rapid Prototyping & Manufacturing Group (RPMG) at DeMonfort University, where
areas of the powder bed are selectively treated to promote absorption by particular IR
radiation will be described in this paper. The advantages of this approach and the
limitations which must be overcome through further research will be fully discussed.",,,,,,
"['El-Desouky, A.', 'Read, A.L.', 'Bardet, P.M.', 'Andre, M.', 'LeBlanc, S.']",2021-10-21T15:41:29Z,2021-10-21T15:41:29Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89400,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'thermoelectric material', 'bismuth telluride']",Selective Laser Melting of a Bismuth Telluride Thermoelectric Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fd699b9c-ee55-4430-a7e5-d0ddd2e57e21/download,University of Texas at Austin,"Selective Laser Melting (SLM) technology is a rapidly growing solid freeform fabrication
tool because it is cost effective, reduces production time of complex shapes, and accommodates a
range of material systems such as metals, ceramics, polymers, intermetallics and composites. This
work presents the first-ever results for SLM performed on a semiconducting thermoelectric
material, bismuth telluride (Bi2Te3), using a Nd:YLF pulsed laser. The evolution of the localized
melt lines formed under different processing parameters such as laser power and scan speed was
investigated. Melt lines were evident on the top surface of the powder compacts under all
investigated processing conditions. However, cross-sections taken across the melt lines revealed
material removal at the irradiation site with minimum consolidation in the subsurface.
Experimental results demonstrate that it is possible to laser melt Bi2Te3 powder, which enables
new possibilities in additive manufacturing of 3D semiconductor thermoelectric components.",,,,,,
"['Zhang, Jinliang', 'Song, Bo', 'Zhang, Lei', 'Liu, Jie', 'Shi, Yusheng']",2021-11-10T22:59:32Z,2021-11-10T22:59:32Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90202', 'http://dx.doi.org/10.26153/tsw/17123']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'aluminum alloys', 'microstructure', 'densification', 'mechanical property']","Selective Laser Melting of Al6061 Alloy: Processing, Microstructure, and Mechanical Properties",Conference paper,https://repositories.lib.utexas.edu//bitstreams/f3b80e0f-18b7-47a6-aeba-4b336a655c5a/download,University of Texas at Austin,"Selective laser melting (SLM) is considered as one of the most promising additive
manufacturing (AM) technologies. Aluminum alloy is of wide application potentiality due to their
high specific strength and heat resistance. In this study, Al6061 alloy was prepared via selective
laser melting (SLM) and densification, microstructure and properties were investigated
systematically. It was found that process parameters including laser power and scanning rate have
a great effect on the forming quality and the porosity of the samples. The α-Al phase is observed
in XRD results and (200) is the preferable orientations of α-Al crystal in the SLM process. The
microstructure can be divided into three areas: fine grained area, coarse grained area and heat
affected area. As for the nanohardness, with the increase of laser power, the elastic modulus and
hardness of SLM aluminum alloy show the trend of increasing first and then decreasing, and with
the increase of scanning speed, the hardness of SLMed aluminum alloy is gradually reduced. With
the increasing laser power and decreasing scanning rate, the elastic modulus and hardness of the
samples increased first and then decreased.",,,,,,
"['Hu, Zhiheng', 'Zhu, Haihong', 'Qi, Ting', 'Zhang, Hu', 'Zhang, Changchun', 'Zeng, Xiaoyan']",2021-11-02T19:33:58Z,2021-11-02T19:33:58Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89876,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['AlCu5MnCdVA', 'selective laser melting', 'formability', 'microstructure', 'mechanical property']","Selective Laser Melting of AlCu5MnCdVA: Formability, Microstructure and Mechanical Properties",Conference paper,https://repositories.lib.utexas.edu//bitstreams/4379c31f-c8c1-4073-960f-f5cd8e878323/download,University of Texas at Austin,"Selective laser melting (SLM) is an additive manufacture (AM) technique that uses powders
to fabricate 3D parts directly. Many researchers are interested in the formability and properties of
the established materials manufactured by SLM. The proposed paper illustrates the formability,
microstructure and mechanical properties of selective laser melted AlCu5MnCdVA. In this
research, crack-free samples with relative density of nearly 100% were produced by SLM from gas
atomized powders. Typical columnar crystal and inhomogeneous element distribution were
obtained. The mechanical properties were test for the SLMed samples.",,,,,,
"['Vandenbroucke, Ben', 'Kruth, Jean-Pierre']",2020-02-27T20:50:33Z,2020-02-27T20:50:33Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80105', 'http://dx.doi.org/10.26153/tsw/7126']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Rapid Prototyping,Selective Laser Melting of Biocompatible Metals for Rapid Manufacturing of Medical Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c1f9951a-7f6f-4285-a09c-adf18b42d611/download,,"In recent years, digitizing and automation have gained an important place in fabrication of
medical parts. Rapid Manufacturing could be very suitable for medical applications due to their
complex geometry, low volume and strong individualization. The presented study investigates
the possibility to produce medical or dental parts by Selective Laser Melting (SLM). The SLMprocess is optimized and fully characterized for two biocompatible metal alloys: TiAl6V4 and
CoCrMo. This paper reports on mechanical and chemical properties and discusses geometrical
feasibility including accuracy and surface roughness. The potential of SLM as medical
manufacturing technique is proved by a developed procedure to fabricate frameworks for
complex dental prostheses.",,,,,,
"['Mumtaz, K. A.', 'Hopkinson, N.']",2020-03-10T17:45:42Z,2020-03-10T17:45:42Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80241', 'http://dx.doi.org/10.26153/tsw/7260']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Melting,Selective Laser Melting of Inconel 625 using Pulse Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c5c6a417-dc08-4f72-80b3-a70a45f72246/download,,"Pulse shaping is a technique used to temporally distribute energy within a single laser
pulse. This allows the user to have an added degree of control over the heat delivered to the
laser material interaction zone. Pulses that induce a gradual heating or a prolonged cooling
effect can be generated with peak power/pulse energy combinations specifically tailored to
control melt pool properties and eventual part formation. This investigation used a pulsed
550W Nd:YAG laser to melt 0.1mm layers of Inconel 625 from a powder bed. Initially a set
of optimization experiments were completed to develop laser parameters that enabled the
production of thin wall parts with low top and side surface roughness. Thin wall parts were
then built using pulse shape control employing a variety of pulse energy distributions. Parts
built with and without pulse shape control were measured for width, top and side surface
roughness. The effectiveness of pulse shaping control is discussed including potential
benefits for use within Selective Laser Melting (SLM).",,,,,,
"['Wiria, Florencia Edith', 'Sing, Swee Leong', 'Yeong, Wai Yee']",2021-11-04T21:08:36Z,2021-11-04T21:08:36Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90029', 'http://dx.doi.org/10.26153/16950']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'titanium-tantalum alloy', 'orthopedic biomaterial', 'biomaterial', 'selective laser melting']",Selective Laser Melting of Novel Titanium-Tantalum Alloy as Orthopedic Biomaterial,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa4256e0-b6dd-4453-9381-12b6ec4da953/download,University of Texas at Austin,"Selective laser melting (SLM) is an additive manufacturing (AM) technique that is
capable of fabricating complex functional three-dimensional (3D) metal parts directly from the
complete melting and fusion of powders. As a powder bed fusion technology, SLM has the
potential to expand its material library by forming alloys that were previously difficult to
achieve by using metal powder mixtures that can be customized according to the application
requirements.
Titanium-tantalum (TiTa) is a material that has potential uses in biomedical
applications due to its high strength-to-modulus ratio. However, it is still not widely used
because it is difficult to obtain. SLM is chosen as the method to form this alloy due to its
versatility in processing metallic materials and good results obtained from commercially pure
titanium (cpTi). Preliminary studies using cpTi lattice structures designed for biomedical
applications were carried out. This research aims to develop TiTa as a material to be potentially
used in biomedical field by investigating its processing window, resulting microstructure, and
mechanical properties.",,,,,,
"['Stoffregen, H.A.', 'Fischer, J.', 'Siedelhofer, C.', 'Abele, E.']",2021-10-05T14:59:28Z,2021-10-05T14:59:28Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88387', 'http://dx.doi.org/10.26153/tsw/15326']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['porous structures', 'selective laser melting', 'lattice structures', 'Center of Smart Interfaces', 'Institute of Production Management, Technology and Machine Tools']",Selective Laser Melting of Porous Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63f90e73-f3a7-4fac-a60e-45ed3cffe11b/download,University of Texas at Austin,"Within the Center of Smart Interfaces “Understanding and Designing Fluid Boundaries”,
a German Excellence Initiative, the Institute of Production Management, Technology and
Machine Tools examines the manufacturing of porous structures by using selective laser melting
(SLM). In this paper two different strategies are presented in order to obtain porosity: One
strategy is to manufacture geometrically defined lattice structures. SLM allows here complex
geometries that cannot be manufactured by conventional technologies to be built. The second
approach is to manufacture geometrically undefined porosity by a specific modification of
exposure parameters. The SLM generated porous structures are investigated with respect to the
heat and mass transfer. The research focus is to increase the efficiency of spraycooling effects
and the manipulation of the Leidenfrost point.",,,,,,
"['Yap, C.Y.', 'Du, Z.', 'Chua, C.K.', 'Dong, Z.L.']",2021-10-27T21:45:15Z,2021-10-27T21:45:15Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89625,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'tin']",Selective Laser Melting of Pure Tin: Microstructure Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aeddd3a5-0443-4eda-861c-1cc0f07cfbc2/download,University of Texas at Austin,"Selective Laser Melting (SLM) of pure tin was examined and 3D samples were
successfully fabricated. High relative density of 99.9 % was achieved. Microstructure study was
carried out via a combination of X-ray diffraction (XRD), light microscopy (LOM) and electron
backscatter diffraction (EBSD). Under LOM, columnar structures, some spanning the entire
height of the sample, are observed in the vertical plane. This study also examines the variation of
relative density against process parameters such as hatch spacing and the input volumetric energy
density for the SLM of tin.",,,,,,
"['Badrinarayan, B.', 'Barlow, J.W.']",2018-04-17T18:28:08Z,2018-04-17T18:28:08Z,1991,Mechanical Engineering,doi:10.15781/T2057D90F,http://hdl.handle.net/2152/64346,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'laser sintering', 'copper', 'polymer', 'part density', 'dwell time', 'shrinkage']",Selective Laser of a Copper-PMMA System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7b3361c1-4e59-411e-b225-5c6bea5d9f39/download,,"The Selective Laser Sintering process was used to manufacture green copper parts from a
copper-polymer mixture. PMMA was used as the polymer binder for the metal. The green
part was fired in a furnace under reducing conditions to obtain a pure metal part. The
metal-polymer system and the conditions used to make parts are described in this paper.
The effect of laser parameters and particle sizes on part density are also discussed.
Keywords: laser sintering, copper, polymer, part density, dwell time, shrinkage.",,,,,,
"['Jakubenas, K.', 'Marcus, H.L.']",2018-10-03T18:25:12Z,2018-10-03T18:25:12Z,1994,Mechanical Engineering,doi:10.15781/T2T14V796,http://hdl.handle.net/2152/68671,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['selective laser pyrolysis', 'polycarbosilane', 'polymeric precursor']",Selective Laser Pyrolysis for Solid Free-FonTI Fabrication of Silicon Carbide,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aeec8e3f-b9c8-4324-bd39-78835150becb/download,,"Selective laser pYrolysis rapidly decomposes a polymeric precursor to form a cohesive
ceramic shape. The considerable shrinkage and porosity during pYrolysis of pure
precursor can be modified by the addition of either inert or reactive fillers. With
polycarbosilane as the polymeric precursor, the process forms shapes of ~-SiC and, by
using fillers, composites of ~-SiC/Al4C3/Al, ~-SiC/TiC/Ti, and ~-SiC/ZrC/Zr. The
technique offers some potential for ceramic shapes with custom designed composition and
microstructure including nanometer grain size.",,,,,,
"['Ku, C.W.', 'Gibson, I.', 'Cheung, W.L.']",2019-10-22T18:12:35Z,2019-10-22T18:12:35Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76332', 'http://dx.doi.org/10.26153/tsw/3421']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Polystyrene,Selective Laser Sintered CastForm™ Polystyrene with Controlled Porosity and Its Infiltration Characteristics by Red Wax,Conference paper,https://repositories.lib.utexas.edu//bitstreams/063db525-e2a4-4d91-b8cd-545ddd8655f0/download,,"This paper focuses on the manufacture of polymer-based components with controlled
porosity using selective laser sintering (SLS) and on their infiltration characteristics by red wax.
CastFormTM Polystyrene (CF) samples with various densities were created by controlling the
laser energy density. Wax was then infiltrated into the sintered specimens at around 638C to
648C. The microstructures of the sintered specimens were examined using scanning electron
microscopy. The physical density was found to increase with increasing energy density and it
reached a maximum at energy density of 0.11 J/mm2
. The infiltration rate and mass of infiltrant
absorbed in a given time were found to increase with increasing porosity. However, none of the
specimens could be fully infiltrated and about 10 – 20 % of porosity still remained regardless of
energy density used for the sintering process. Finally, the potential applications of SLS parts with
controlled porosity will be discussed.","This paper describes a project funded by the Research Grants Council on ‘Functionally
graded part fabrication based on the SLS process’.",,,,,
"['Kolan, Krishna C.R.', 'Doiphode, Nikhil D.', 'Leu, Ming C.']",2021-10-01T00:35:18Z,2021-10-01T00:35:18Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88311', 'http://dx.doi.org/10.26153/tsw/15252']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['13-93 glass', 'synthetic scaffolds', 'additive manufacturing', 'selective laser sintering', 'freeze extrusion fabrication', 'bone repair']",Selective Laser Sintering and Freeze Extrusion Fabrication of Scaffolds for Bone Repair Using 13-93 Bioactive Glass: A Comparison,Conference paper,https://repositories.lib.utexas.edu//bitstreams/918ab21d-d139-4116-aa36-35423fb7b575/download,,"13-93 glass is a third-generation bioactive material which accelerates the bone’s natural ability to
heal by itself through bonding with surrounding tissues. It is an important requirement for
synthetic scaffolds to maintain their bioactivity and mechanical strength with a porous internal
architecture comparable to that of a human bone. Additive manufacturing technologies provide a
better control over design and fabrication of porous structures than conventional methods. In this
paper, we discuss and compare some of the common aspects in the scaffold fabrication using two
such processes, viz. selective laser sintering (SLS) and freeze extrusion fabrication (FEF).
Scaffolds fabricated using each process were structurally characterized and microstructure
analysis was performed to study process differences. Compressive strength higher than that of
human trabecular bone was achieved using SLS process and strength almost comparable to that
of human cortical bone was achieved using FEF process.",,,,,,
"['Griffin, E. Alair', 'McMillin, Scott']",2018-10-03T19:40:18Z,2018-10-03T19:40:18Z,1995,Mechanical Engineering,doi:10.15781/T24B2XQ22,http://hdl.handle.net/2152/68684,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['solid freeform fabrication', 'CAD', 'LPE']",Selective Laser Sintering and Fused Deposition Modeling Processes For Functional Ceramic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50b5afb3-1483-4fd4-be6d-17fe41b01a18/download,,"A variety ofsolid freeform fabrication (SFF) techniques have been developed to
produce prototype parts directly from a computer-aided drawing (CAD) without any hard
tooling, dies or molds [1]. Most ofthese techniques use polymer, wax, or paper materials
to produce the parts.
These techniques, with SOlne lnodifications, can be used to rapidly prototype
functional ceramic parts. Once developed, these techniques could also be used to
manufacture small quantities of ceralnic parts on a just-in-time basis. Fabrication using
conventional techniques is a costly, titne-consuming, and inflexible process when a few
ceramic prototypes or when small quantities of parts are needed.
Solid freeform fabrication of ceralnic parts offers numerous advantages over
conventional processing. Prototypes can be prepared rapidly and cost-effectively. Design
changes can be made easily and inexpensively. Larger nUlnber of design options can be
investigated. Parts can be designed and engineered to take advantage ofthe stronger
properties of ceramics, while minimizing the weaker ones. Typically, ceramic parts are
made using an existing design, regardless ofthe material used for the original part. The
ability to rapidly prototype a ceralnic component will contribute to concurrent
engineering, a popular design process being used today.
Lone Peak Engineering (LPE) is developing three SFF processes for ceramics based on:
1. Selective Laser Sintering (SLS)
2. Fused Deposition Modeling (FDM)
3. Lalninated Object Manufacturing (LOM™)
TMLOM is a registered trademark of Helisys, Inc. Torrance, CA
25
This paper discusses preliminary results with the SLS and FDM processes. LPE's ceramic
LOM based process has been reported at this symposium [2] as well as at other meetings
and in different publications [3].",,,,,,
"['Vallabhajosyula, Phani', 'Bourell, David L.']",2020-03-11T14:33:48Z,2020-03-11T14:33:48Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80244', 'http://dx.doi.org/10.26153/tsw/7263']",eng,2008 International Solid Freeform Fabrication Symposium,Open,selective laser sintering,Selective Laser Sintering and Post Processing of Fully Ferrous Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b917eb19-58d4-41b2-91db-a74eb787bd4f/download,,"Commercially available steel for indirect SLS (LaserFormtm A6 tool steel) is normally
post-process infiltrated with a copper-based material. While such parts have high thermal
conductivity necessary for short- and medium-run injection molding dies, they are weakened by
the second phase with limited high temperature stability. This paper deals with a modification to
the commercial process whereby a low-melting-point cast iron is substituted for the copper alloy
infiltrant. A predictive model is presented that describes the part equilibrium solid fraction at the
infiltration temperature as a function of the green density and infiltration temperature. In an
experimental study, green parts were fabricated using LaserFormtm A6 tool steel powder. They
were then heated in vacuum to drive off the binder and infiltrated with ASTM A532 white cast
iron. During infiltration, an equilibrium state is established between the solid SLS steel part and
liquid cast iron associated primarily with carbon diffusion from the cast iron into the tool steel.
The equilibrium state is governed by the carbon content of the steel and cast iron, the relative
density of the steel part prior to infiltration and the infiltration temperature. In some cases guided
by Ashby densification maps, pre-sintering of the tool steel green part was performed to increase
the initial relative density of the solid metal.",,,,,,
"['Subramanian, Kamatchi', 'Zong, Guisheng', 'Marcus, H.L.']",2018-04-19T16:09:12Z,2018-04-19T16:09:12Z,1992,Mechanical Engineering,doi:10.15781/T20000H37,http://hdl.handle.net/2152/64378,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SLS', 'SLRS']",Selective Laser Sintering and Reaction Sintering of Ceramic Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf68c35a-443a-411f-b067-28da4f713b36/download,,"Selective Laser Sintering and Reaction Sintering (SLS and SLRS) are used as
methods of forming composites and preforms. Al20jAI and SiC/AI were studied as
model systems. Ceramic and metallic powders are mixed and locally sintered using SLS
and SLRS. Post processing heat treatment was also employed. Wettability and residual
stress aspects of this process are discussed.",,,,,,
"Kent, Nutt",2018-04-17T16:36:36Z,2018-04-17T16:36:36Z,1991,Mechanical Engineering,doi:10.15781/T29K4694P,http://hdl.handle.net/2152/64328,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'CAE', 'DFM', 'DFA']",Selective Laser Sintering as a Rapid Prototyping and Manufacturing Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b576cca0-c8be-4a01-96fb-ffb28daf7043/download,,"With accelerating growth and competition in today's global marketplace, manufacturers
face the daunting tasks of meeting changing market needs, maintaining market share, and
reasserting a technological edge. Now, more than ever, adopting new technologies is a key
component in ensuring the successful outcome of new projects--and in producing longterm
market success.",,,,,,
"['Kolan, Krishna C.R.', 'Leu, Ming C.', 'Hilmas, Gregory E.', 'Velez, Mariano']",2021-09-30T18:40:04Z,2021-09-30T18:40:04Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88274', 'http://dx.doi.org/10.26153/tsw/15215']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['bioactive glass', 'bone tissue repair', 'selective laser sintering', 'scaffold fabrication']",Selective Laser Sintering of 13-93 Bioactive Glass,Conference paper,https://repositories.lib.utexas.edu//bitstreams/34f48c7c-47a5-468f-9800-1109eea67f0d/download,University of Texas at Austin,"Bioactive glasses are more promising than biopolymers in fabricating scaffolds for bone tissue
repair because they convert to hydroxyapatite, when implanted in vivo. Both direct and indirect
selective laser sintering (SLS) methods of 13-93 bioactive glass were considered in this research
to study the feasibility of fabricating scaffolds for bone repair applications. Stearic acid was used
as the binder in the indirect method to fabricate the scaffolds. The green scaffolds underwent
binder burnout and sintering at various soaking conditions between 6750C and 7000C, achieving
a maximum compressive strength of 23.6 MPa, which is higher than that of the human
cancellous bone. The sintered scaffolds had a pore size varying between 300 µm and 800 µm
with 50% apparent porosity.",,,,,,
"Subramanian, Kam",2018-05-03T20:01:46Z,2018-05-03T20:01:46Z,1993,Mechanical Engineering,doi:10.15781/T2M03ZF44,http://hdl.handle.net/2152/65079,,1993 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'Selective Laser Sintering', 'Center for Materials Science and Engineering']",Selective Laser Sintering of A1203-,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7a59340-6c60-4c29-b8b8-e37aef0351cb/download,,,,,,,,
"['Lee, Insup', 'Manthiram, A.', 'Marcus, H.L']",2018-10-03T18:17:05Z,2018-10-03T18:17:05Z,1994,Mechanical Engineering,doi:10.15781/T26970H2C,http://hdl.handle.net/2152/68668,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['optimum composite system', 'solid freeform fabrication', 'CAD']",Selective Laser Sintering of Alumina-Boron Oxide Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9feabc5-da14-4bae-8bbf-4bec8c3176ca/download,,"The selection of an optimum composite system for selective laser sintering (SLS) is based on
materials properties such as the melting point and the wettability between the components in the
composite powder. The alumina-boron oxide composite system is attractive for SLS because the
presence of the low melting component B203 (melting point 4500 C) can enhance sintering. A
better wetting of solid alumina powder by molten boron oxide can also aid densification process.
The alumina-boron oxide conlposite system has been investigated by SLS and selective laser
reactive sintering (SLRS). The role of boron oxide content as a binder, laser power density, and
secondary heat treatment on the microstructure and mechanical properties is discussed.",,,,,,
"['Lee, Insup', 'Manthiram, A.', 'Marcus, H.L.']",2018-10-03T20:53:54Z,2018-10-03T20:53:54Z,1995,Mechanical Engineering,doi:10.15781/T2GM82732,http://hdl.handle.net/2152/68689,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'alumina', 'x-ray diffraction']",Selective Laser Sintering of Alumina-Zinc Borosilicate Glass Composites using Monoclinic HB02 as a Binder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e61f83db-2f43-41a3-ae15-303451ba7297/download,,"Selective Laser Sintering (SLS) process has been employed to fabricate alumina-glass
composites using as an inorganic binder monoclinic HB02. Subsequent post-thermal processing
of green SLS parts at various temperatures yielded glass-ceramic composites. The crystalline
phases and microstructural evolution at each fIring temperature were identified by X-ray diffraction
analysis and Scanning Electron Microscopy. The role of glass content, firing temperature, and
alumina particle size on the densification and bend strength of fired samples were studied. In
addition, further densification was made through infiltration of colloidal silica into the fIred, porous
samples.",,,,,,
"['Manriquez-Frayre, J.A.', 'Bourell, D.L.']",2018-04-10T18:38:39Z,2018-04-10T18:38:39Z,1990,Mechanical Engineering,doi:10.15781/T2B27Q79P,http://hdl.handle.net/2152/64245,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'laser processing', 'energy dispersive spectroscopy']",Selective Laser Sintering of Binary Metallic Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a94e6660-f638-4fb0-91a9-6fd5375a0d29/download,,"A selective laser sintering technique has been used to process metal powders and
powder blends. Precursor powders include copper, tin, a 70Pb-30Sn solder and their blends.
Excessive balling due to surface free energy effects occurred in single layer tests when the
laser fluence was sufficient to cause melting of monolithic tin or solder. Improvements in
single layer quality were obtained using copper-solder powder blends in a reducing
atmosphere. The binary powder layers were characterized metallographically and the effect of
processing parameters such as laser fluence and scan speed were assessed. Post-process
annealing improved interparticle wetting and part strength. The influence of ZnCl2 flux was
investigated when present as a coating in copper-solder blends. Multiple layer tests were
performed on the most promising powder blends and the results are presented.",,,,,,
"['Lorrison, J.C.', 'Goodridge, R.D.', 'Daigarno, K.W.', 'Wood, D.J.']",2019-10-22T17:23:44Z,2019-10-22T17:23:44Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76320', 'http://dx.doi.org/10.26153/tsw/3409']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Sintering,Selective Laser Sintering of Bioactive Glass-Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f706ae15-7e4e-4dbc-8305-31662761440a/download,,"An initial investigation was held into the feasibility of producing bone replacement
implants from a bioactive glass-ceramic using the Selective Laser Sintering (SLS) process. The
work presented considers both a direct and an indirect approach, where the material is sintered
with a polymer binder and subsequently post-processed. An existing material with potentially
suitable biological and mechanical properties was selected from the range of apatite-mullite
glass-ceramics in the SiO2-Al2O3-CaO-CaF2-P2O5 series. The viability of using this material with
the SLS process was then tested, and the process route and resulting material properties
characterised. It is concluded that both direct and indirect SLS processes have potential in the
manufacture of personalised bone replacement applications.",,,,,,
"['Lee, Goonhee', 'Barlow, J.W.']",2018-05-03T20:05:32Z,2018-05-03T20:05:32Z,1993,Mechanical Engineering,doi:10.15781/T26Q1T10X,http://hdl.handle.net/2152/65082,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'SLS', 'Department of Chemical Engineering']",Selective Laser Sintering of Bioceramic Materials for Implants,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a7d9750a-4121-4be2-9f91-2b5643c5ca6a/download,,"Selective Laser Sintering (SLS) process is employed for fabrication of biocerarnics
for orthopedic implants. Hydroxyapatite and Calcium Phosphate ceramics are coated with
polymer as a intermediate binder by using a spray drier. Polymer coated materials are
SLS processed to make green parts, which are infiltrated and fired to remove the polymer.
SLS processed green parts of hydroxyapatite have low density due to the small particle
size with large specific surface area. This paper discusses the possibilities and problems in
free-form fabrication of bioceramic.",,,,,,
"['Lee, Gonhee', 'Barlow, J.W.']",2018-10-03T15:29:00Z,2018-10-03T15:29:00Z,1994,Mechanical Engineering,doi:10.15781/T25D8P040,http://hdl.handle.net/2152/68645,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'Polymeric Binder', 'Powder X-ray diffraction']",Selective Laser Sintering of Calcium Phosphate Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47677941-00c0-4206-b379-bc9fe3079ea6/download,,"Since Dejong first observed the similarity between powder X - ray diffraction
pattern ofthe in vivo mineral and the hydroxyapatite (Cas(OH)(P04h ,HA) in 1926,
the calcium phosphate ceramics have received attention as a bone substitute material.
Five calcium phosphates which exhibit different X-ray diffraction patterns are
known to be precipitated from aqueous solution at normal pressure. [1] These are
Ca(HzP04h, Ca(HzP04h-H20, CaHP04 , CaHP04-2H20, and crystalline
precipitate of variable composition of hydroxyapatite with the base formula
Cas(OH)(P04h. Various forms of calcium phosphate compounds, Ca/P ratio range
from 0.5 to 1, are prepared from HA by reacting with phosphoric acid. Thermally
dehydrated calcium phosphates are known to form a CaO and P20 S binary system. It
is known that for the CaO and P20S binary system, the chain phosphates appear
between the orthophosphate (mole ratio ofCaO/P20 S =3) and metaphosphate (mole
ratio ofCaO/P20s =1) and ultraphosphate for which mole ratio ofCaO/P20 s iess
than 1. Particularly in the case ofmetaphosphate, very high degree of
polymerization and as a consequence, good mechanical properties are reported. In
this binary system, mole ratio ofCaO/P20 S less than 55145 forms a glass-like
structure from the melt, and its mechanical properties are known to be nearly same as
those of natural teeth.[2]",,,,,,
"['Lakshminarayan, Uday', 'Ogrydiziak, Stan', 'Marcus, H.L.']",2018-04-10T16:30:03Z,2018-04-10T16:30:03Z,1990,Mechanical Engineering,doi:10.15781/T2MG7GC58,http://hdl.handle.net/2152/64235,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Department of Mechanical Engineering', 'Selective Layer Sintering', 'SLS']",Selective Laser Sintering of Ceramic Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ce95e944-890f-46ac-a6e4-59de3505f3fa/download,,"This paper will focus on efforts to develop the alumina - ammonium phosphate
material system for Solid Freeform Fabrication. When the powder mix is irradiated
with a laser beam, ammonium phosphate ( m.p. """""" 190 0 C ) melts and forms a glassy
phase between the alumina grains. The ""green part"" obtained by laser processing is
then subjected to secondary heat treatment to optimize the properties of the final
composite. The effect of various material, laser and machine parameters on the density,
strength, surface finish and microstructure of the final part are described. One of the
applications for selective laser sintering is its use in directly manufacturing ceramic
molds for the investment casting process. We will describe some of the the results we
have obtained so far in fabricating composite ceramic molds directly and using them to
cast metals.",,,,,,
"['Frayre-Manriquez, J.A.', 'Bourell, D.L.']",2018-04-17T18:21:12Z,2018-04-17T18:21:12Z,1991,Mechanical Engineering,doi:10.15781/T2CF9JQ1W,http://hdl.handle.net/2152/64343,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'SLS', 'Selective Layer Sintering', 'Polymer']",Selective Laser Sintering of Cu-Pb/Sn Solder Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e081bb9d-b0a9-45d5-bf97-1687967d1e97/download,,"Solid Freeform Fabrication (SFF) as an overall approach in the
manufacturing field has been applied to very different areas and on
different materials systems including polymers, ceramics, metals and
vapor phase. Even though it is clear that polymers have enjoyed a rapid
and successful advance in terms of applications, research in the other
areas have shown potential applications as well.
In this paper, Cu-Sn/Pb solder and Cu-Sn blends have been used as
starting material for the Selective Laser Sintering (SLS) manufacture of
SFF objects. The general properties of the objects thus produced are
presented. In particular, density and microstructural characterizations
results are discussed..",,,,,,
"['Neff, Clayton', 'Hopkinson, Neil', 'Crane, Nathan B.']",2021-10-21T16:57:33Z,2021-10-21T16:57:33Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89405,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['diamond lattice structures', 'selective laser sintering', 'elastic modulus']",Selective Laser Sintering of Diamond Lattice Structures: Experimental Results and FEA Model Comparison,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6234856-921d-4c72-8923-3a20fab99170/download,University of Texas at Austin,"Nature utilizes multiple materials with varying properties to create high performance,
integrated systems. In contrast, most additive manufacturing processes are limited to a small set of
compatible materials to fabricate a device. However, the large geometric freedom of AM could
be used to create the effect of multiple properties by creating lattice structures. Prior work has
focused on using this concept to reduce weight in high stiffness structures. This paper will consider
the use of a diamond lattice structures to create the effect of materials with a low elastic modulus
materials. Low stiffness regions are advantageous for energy absorption, vibration isolation, and
reduction of stress due to dimensional or temperature mismatches. The diamond lattice possesses
Face-Centered-Cubic (FCC) elemental configuration possessing tetrahedral angles of 109°
between elements. This allows for a pliable moment exerted on the structure yielding a flexible
and energy absorbent arrangement. A range of devices was fabricated in Nylon 12 (PA 2200)
through Laser Sintering (LS) process with variable element size (thickness) and unit cell size. The
effective stiffness of the structures is compared as a function of these parameters and compared to
numerical simulation. The results show the possibility of tuning the effective elastic modulus by
over four orders of magnitude.",,,,,,
"['Sriram, Vinay', 'Wood, Kristin', 'Bourell, David', 'Beaman, Joseph J.']",2019-11-21T18:37:37Z,2019-11-21T18:37:37Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78563', 'http://dx.doi.org/10.26153/tsw/5619']",eng,2003 International Solid Freeform Fabrication Symposium,Open,DuraForm,Selective Laser Sintering of DuraForm Polyamide with Small-Scale Features,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ceb2ceaa-0985-4e90-96e3-5bab44d5b19f/download,,"Selective Laser Sintering (SLS) has been used to make a fiber management module
having very small feature size and ratios. Currently these modules are made out of
Stereolithography using standard epoxy acrylate materials. SLS has been chosen to make
these modules by the virtue of the material system it offers. The material system was chosen
based on the flame retardant properties. The material used for this study is a DuraformTM
Polyamide and Alumina-Ammonium Phosphate system. Ammonium Phosphate served as the
binder in the Alumina-Ammonium Phosphate system. Experiments were done in order to find
out the minimum feature size possible with the two material systems. Minimum hole
diameters and maximum possible l/d ratios are determined by particle size, shape and
processing conditions. Builds were made in different directions to understand the effect of the
various processing parameters on the system. One particularly noteworthy observation was
that part growth as a proportion of hole diameter became increasingly significant as hole size
decreased. Optical microscopy was performed to measure the hole diameters and also to
reveal the surface roughness. Results indicate material system determines the minimum
diameter of micro-sized holes that can be effectively manufactured using Selective Laser
Sintering.",,,,,,
"['Das, S.', 'Harlan, N.', 'Beaman, J. J.', 'Bourell, D. L.']",2018-11-09T15:21:58Z,2018-11-09T15:21:58Z,1996,Mechanical Engineering,doi:10.15781/T2Q815C0Q,http://hdl.handle.net/2152/69925,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['HIP', 'SLS', 'encapsulate powder']",Selective Laser Sintering of High Performance High Temperature Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a8d1699-d194-4681-8be0-fb0de494fca3/download,,"Hot Isostatic Pressing (HIP) of high performance metal parts is currently done using either a shaped
metal container or a pre-fabricated ceramic mold depending on the part material and geometry. An
alternative method of HIP encapsulation that allows complex part geometry, short cycle time and
minima) potential for container-powder bed interaction is desired. Integral, fully dense metal skins
with complex geometry can potentially be constructed by direct selective laser sintering (SLS). The
advantages ofin-situ HIP encapsulation by direct SLS include the elimination of a secondary container
material and any associated container-powder bed interaction, reduced pre-processing time and a short
HIP cycle. Single and multi-layer specimens of Inconel625, Ti-6AI-4Vand 17-4 PH stainless steel
were produced by direct SLS. Closed porosity in Inconel625 and 17-4 PH stainless steel samples
ranged from 0 to 12% and area porosity from 0.5 to 20%, depending on the laser energy density.
Direct SLS samples ofInconel 625 were subjected to helium leak testing and found to be impervious,
with a leak rate less than lxl0-10 atm eels. These samples met the criteria for containerless hot
isostatic pressing.",,,,,,
"['Hostetler, John M.', 'Goldstein, Jonathan T.', 'Urbas, Augustine M.', 'Gutierrez, Rodrigo E.', 'Bender, Theresa E.', 'Wojnar, Charles S.', 'Kinzel, Edward C.']",2021-10-28T14:24:59Z,2021-10-28T14:24:59Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89648,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['silica parts', 'thermal expansion', 'low density', 'low coefficient', 'selective laser sintering']","Selective Laser Sintering of Low Density, Low Coefficient of Thermal Expansion Silica Parts",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b33959fa-e3b4-4b55-ad02-3df8c5094c56/download,University of Texas at Austin,"This paper presents a study of selective laser sintering of silica-gel. The objective of this
work is to investigate a technique to create free-form, low to zero coefficient of thermal
expansion structures. This offers potential cost savings over the conventional casting of large
pieces of glass-ceramic followed by machining lightening features. In this paper, A CO2 laser is
coupled through a gantry system and focused onto a binder-free silica-gel powder bed (15-40 µm
particles). Prior to writing each layer, powder is dispensed by sifting it onto the build platform
as opposed to a conventional wiper system. This avoids contacting and potentially damaging
sensitive parts. After deposition, the parts are annealed in a furnace to increase their
strength. The influence of various process parameters including scan speed and laser power on
final shape is investigated. In addition, the flexural strength of annealed parts is measured via
three-point bending tests.",,,,,,
"['Hejmadi, Uday', 'McAlea, Kevin']",2018-11-09T15:35:21Z,2018-11-09T15:35:21Z,1996,Mechanical Engineering,doi:10.15781/T2KH0FJ5G,http://hdl.handle.net/2152/69926,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SLS process', 'CAD', 'RapidTool process']",Selective Laser Sintering of Metal Molds: The Rapidtool Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b60c6f61-b5b1-4d20-bf9e-e95b8c03ccba/download,,"Complex three dimensional parts can be manufactured directly from CAD data using rapid
prototyping processes. SLS® Selective Laser Sintering is a rapid prototyping process developed
at the University ofTexas at Austin and commercialized by DTM Corporation. SLS parts are
constructed layer by layer from powdered materials using laser energy to melt CAD specified cross
sections. Polymer, metal, and ceramic powders are all potential candidate materials for this
process. In this paper, a commercial SLS process - the RapidTool Process - which allows metal
molds to be rapidly manufactured is described. With this process, a polymer coated carbon steel
powder is used to fabricate a ""green part"" in the SLS machine. The green part is then placed in a
furnace with blocks of copper and, in a single furnace cycle, the polymer coating is removed and
the steel skeleton is infiltrated with the copper. The resulting steel/coPPer composite material has
durability and thermal conductivity similar to aluminum and can be hand finished using standard
techniques. A finished mold core and cavity set which can be used to mold at least 50,000 parts
with most plastics can be prepared in approximately ten days. The cost to produce most mold
geometries with the RapidTool Process is also comPetitive with traditional mold-making methods.",,,,,,
"['Klatt, Timothy', 'Haberman, Michael', 'Conner Seepersad, Carolyn']",2021-10-12T18:56:05Z,2021-10-12T18:56:05Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88719', 'http://dx.doi.org/10.26153/tsw/15653']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['bistable structures', 'mesostructures', 'honeycombs', 'selective laser sintering']","Selective Laser Sintering of Negative Stiffness Mesostructures for Recoverable, Nearly-Ideal Shock Isolation",Conference paper,https://repositories.lib.utexas.edu//bitstreams/e0f51767-358c-447a-94bb-06774051a85a/download,University of Texas at Austin,"Honeycomb materials are well known for providing lightweight stiffness, strength, and
energy absorption capabilities. For most honeycomb materials, energy absorption occurs when
individual cells collapse progressively. Although it is possible for honeycombs with very low
relative density to collapse via elastic buckling, honeycombs with typical relative densities
collapse due to plastic yielding and buckling of the cell walls, such that the energy absorption is
nonrecoverable. In this paper, mono-stable negative stiffness unit cells are investigated for
constructing honeycomb mesostructures with high levels of recoverable energy absorption.
Negative stiffness is achieved by incorporating curved beams into each unit cell. When subject
to transverse loading, the curved beams exhibit negative stiffness behavior as they transition
from one curved geometry to another in a snap-through type of motion that absorbs energy
elastically at a relatively constant plateau stress. The plateau stress at which this energy
absorption occurs can be tailored via the geometry of the unit cell. Preliminary experiments
indicate that the structures can absorb significant amounts of energy by requiring nearly-constant-force to increase deformation as the structure transitions between snap-through
configurations. Unlike traditional honeycombs, the negative stiffness mesostructures are self-resettable and therefore reusable. Using SLS as a means of fabrication, they can also be
customized for specific shock events and even functionally graded to offer shock isolation for
transient loads of various amplitudes.",,,,,,
"['Schultz, Jeffrey P.', 'Martin, Julie P.', 'Kander, Ronald G.', 'Suchicital, Carlos T.A.']",2019-09-20T18:28:35Z,2019-09-20T18:28:35Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75927', 'http://dx.doi.org/10.26153/tsw/3026']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Alloying,Selective Laser Sintering of Nylon 12-PEEK Blends Formed by Cryogenic Mechanical Alloying,Conference paper,https://repositories.lib.utexas.edu//bitstreams/532d12ec-ee5d-4f45-aedb-f14b358246cc/download,,"Cryogenic mechanical alloying (CMA) has been shown to be an effective means for producing composite powders with co-continuous phases throughout each particle. Consolidation of these composite particles via SLS presents the possibility of forming parts with a co-continuous microstructure. In this work the effects of milling time and PEEK volume fraction on the microstructure and mechanical properties of laser sintered Nylon 12-PEEK blends is studied. In both blends, the PEEK phase is incorporated to increase mechanical strength, stiffness and heat deflection temperature. Transmission electron microscopy and scanning electron microscopy is utilized to investigate the microstructure of the CMA powder and laser sintered parts.",,,,,,
"['Faustini, Mario C.', 'Neptune, Richard R.', 'Crawford, Richard H.', 'Stanhope, Steven J.']",2020-02-27T20:36:29Z,2020-02-27T20:36:29Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80102', 'http://dx.doi.org/10.26153/tsw/7123']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Passive dynamic ankle-foot orthoses,Selective Laser Sintering of Passive Dynamic Ankle-Foot Orthoses,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f17d54af-5b69-41fc-a227-514c3855aa69/download,,"Passive dynamic ankle-foot orthoses (AFO’s) are used to improve gait performance in
those with various neuromuscular disorders. An important design characteristic of passive
dynamic AFOs is the storage and release of elastic energy within its structure to help satisfy the
energetic demands of walking. Thus, minimizing energy dissipation through internal friction is a
fundamental criterion for selecting the appropriate AFO material. This study compared the
mechanical damping of a carbon-fiber AFO to three geometrically identical AFO’s fabricated
using selective laser sintering with different materials. Mechanical damping characteristics
ranked the materials as Nylon 11 (best), followed by DuraformTM PA and DuraformTM GF
(worst).",,,,,,
"['Childs, T.H.C.', 'Cardie, S.', 'Brown, J.M.']",2018-10-03T18:22:47Z,2018-10-03T18:22:47Z,1994,Mechanical Engineering,doi:10.15781/T2XS5K244,http://hdl.handle.net/2152/68670,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['sintering of polycarbonate', 'selective laser sintering', 'temperature distribution']","Selective Laser Sintering of Polycarbonate at Varying Powers, Scan Speeds and Scan Spacings",Conference paper,https://repositories.lib.utexas.edu//bitstreams/3487242d-8b34-41a1-8b34-24a12d726ee2/download,,"A benchmark study (1) has shown selective laser sintering to be the equal of or to
have accuracy advantages over other processes for creating parts of size over 10 mm.
Experience is needed to achieve best accuracies, as with other processes. This paper is
(for us) a first step in understanding the relation between sintering parameters, part
size and acuracy.
Work at the University of Texas at Austin (2-4) has established that the sintering
of polycarbonate can be understood in terms of a rate model driven by viscous and
surface tension effects. Material properties are such that a sharp boundary exists
between sintered and unsintered material. When full density is not achieved in a part,
density within a single layer varies from fully sintered to totally unsintered; measured
part density is thus a mean of widely varying values. Published work (3-4) uses a onedimensional
non-steady state heat flow model to calculate the temperature profile and
densification beneath the surface and concentrates on the effects on this of material
properties varying with temperature and during sintering. In this paper, these
variations are ignored but a three dimensional non-steady heat flow is used to enable
edge effects to be estimated. Density gradients at edges are assumed to be responsible
for variations of accuracy with sintering parameters, part size, part shape and
orientation.",,,,,,
"['Wahab, M. S.', 'Dalgarno, K. W.', 'Cochrane, R. F.']",2020-03-09T15:30:48Z,2020-03-09T15:30:48Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80200', 'http://dx.doi.org/10.26153/tsw/7219']",eng,2007 International Solid Freeform Fabrication Symposium,Open,polymer nanocomposite,Selective Laser Sintering of Polymer Nanocomposites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bde27445-6d43-477b-bf37-f9abb136fe67/download,,"This paper describes the fabrication and characterization of polymer nanocomposite (PNC)
materials for use in the selective laser sintering (SLS) process. PNC materials are of great
interest generally because of their excellent physical properties, and offer excellent potential
in rapid manufacturing of structural polymeric parts. Three different nano additive materials
have been used: cerium oxide IV, yttrium stabilized zirconia, and layered Hectorite clay.
These materials have been used to reinforce PA6 polymer using solution blending and spray
drying to create powder with particle sizes in the range of 5-40 µm. The mechanical
properties and microstructure of the PNC materials have been evaluated and the results
compared to those of unfilled polymer.",,,,,,
"['Wang, Hongyun', 'Bourell, David L', 'Beaman Jr., Joseph J.']",2018-12-05T20:37:14Z,2018-12-05T20:37:14Z,1997,Mechanical Engineering,doi:10.15781/T2VT1H935,http://hdl.handle.net/2152/71416,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'CAD']",Selective Laser Sintering of Quartz Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db73e8e5-1412-4756-9cf6-fd9ae13bdd6f/download,,"This research describes the feasibility of fusing quartz powder by Selective Laser Sintering
(SLS). SLS is a method of rapid prototyping three-dimensional objects from a computer-aided
design database. The effects of different processing parameters, including powder size, laser
power and scan mte were explored. Single and multiple layer specimens have been made. The
resulting structures were evaluated using SEM and the density of the multiple-layer structure was
detected by a geometrical mass/volume technique. It was determined that particle size was the
dominant variable affecting part quality. Smaller and spherical unifonn particles are preferred.
Future work will concentrate on optimizing powder size and shape and higher laser power.",,,,,,
"['Gill, Toby', 'Hon, Bernard']",2019-10-25T16:05:05Z,2019-10-25T16:05:05Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77441', 'http://dx.doi.org/10.26153/tsw/4530']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Laser Sintering,Selective Laser Sintering of SiC/Polyamide Matrix Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9db2ff3f-bcf2-425b-8171-b443ffe46305/download,,"This paper presents an experimental study into the production of particulate Silicon
Carbide/Duraform Polyamide matrix composites via the selective laser sintering (SLS) process.
FEPA standard SiC grits, F240 and F360, were each individually blended with the commercially
available Duraform Polyamide, to produce blend compositions of 50 and 60 volume percent SiC
for direct SLS processing. A full factorial experimental approach was applied to examine the
effects and interactions of laser power, scan speed, scan spacing and layer thickness, with
regards to the mechanical and physical properties of sintered parts. Analysis of parameter
interactions and individual main effects as well as Pareto analysis for all parameter combinations
are presented for the responses of part porosity and strength.","The authors would like to acknowledge the financial support from the EPSRC and the
technical support and assistance of the PIDC.",,,,,
"['Hauser, C.', 'Childs, T.H.C.', 'Dalgamo, K.W.']",2019-03-12T17:55:45Z,2019-03-12T17:55:45Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73606', 'http://dx.doi.org/10.26153/tsw/748']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'Selective laser sintering']",Selective Laser Sintering of Stainless Steel 314S HC Processed Using Room Temperature Powder Beds,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d5b54c32-7bb3-4eed-b890-8e7b570e27d7/download,,"Metal powder bed pre-heating is a proposed route for the homogenisation of
temperature gradients that can otherwise cause individual layer warping and cracking in direct
metal Selective Laser Sintering (SLS). However, the high temperatures involved complicate a
relatively simple process. This paper reports on the conditions for successful small scale SLS
of binderless stainless steel 314S powders within the surrounds of a room temperature powder
bed. Results show that a scan length around 15.0mm and a scan spacing around 0.275mm
produce sintered layers showing no signs of warping. Experimentation also indicates that
single layer shape. effects warping but length oflayer propagation does not.",,,,,,
"['Harlan, Nicole', 'Park, Seok-Min', 'Bourell, David L.', 'Beaman, Joseph J.']",2019-03-12T20:46:42Z,2019-03-12T20:46:42Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73609', 'http://dx.doi.org/10.26153/tsw/751']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'tetragonal']",Selective Laser Sintering of Zirconia with Micro-Scale Features,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2b10c56-09f5-413e-a26a-5311a95ce2a4/download,,"Recent work in Selective Laser Sintering of ceramics at the University of Texas at Austin demonstrates
the capability to produce zirconia parts with fine features. Zirconia powder was pre-processed into
spherical particles, laser sintered with a sacrificial polymer binder, infiltrated and post-sintered to higher
density. Optical micrographs show that hole sizes of 180 /-tm are possible in fully ceramic components.",,,,,,
"['Klocke, F.', 'Wirtz, H.']",2019-02-26T20:58:40Z,2019-02-26T20:58:40Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73502', 'http://dx.doi.org/10.26153/tsw/652']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Investment Casting', 'Selective Laser Sintering']",Selective Laser Sintering of Zirconium Silicate,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb7dc01e-5ce3-467e-bb5d-9c9bb074ffde/download,,"The Fraunhofer Institute of Production Technology (IPT) and the Fraunhofer Institute of
Laser Technology (ILT) have joined forces in a project dedicated to Selective Laser Sintering
(SLS) ofmetals and ceramics, funded by the German Government and 6 industrial partners.
Selective Laser Sintering of zirconium silicate as a ceramic material used for investment
casting shells and cores is an attractive alternative to the conventional, time-consuming way of
producing these shells from a wax master. This paper will present current process results
concerning laser sintering of shells made from zirconium silicate and explain the related
potentials and benefits.",,,,,,
"['Williams, John', 'Miller, David', 'Deckard, Carl']",2018-11-16T15:47:32Z,2018-11-16T15:47:32Z,1996,Mechanical Engineering,doi:10.15781/T2T43JN9H,http://hdl.handle.net/2152/70290,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'radiation', 'thermal gradients']","Selective Laser Sintering Part Strength as a Function of Andrew Number, Scan Rate and Spot Size",Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a2f3611-67e0-42c7-bbb3-f869af44f4d4/download,,"Selective Laser Sintering has been modeled analytically and numerically, and
studied experimentally. Further investigation is necessary to couple the results of
modeling with experimental data. At Clemson University, numerical modeling of
heat transfer phenomena is used to predict temperatures within the powder layer
as a function of process parameters. Efforts are focused on delivering process
speed up through improved process understanding. Initial modeling results and
current understanding of the effects of process parameters on the strength
properties offreeform parts produced by the SLS process are presented.",,,,,,
"['Cottle, Rand D.', 'Birmingham, Britton', 'Eliezer, Zwy', 'Marcus, Harris L.']",2018-11-08T15:07:43Z,2018-11-08T15:07:43Z,1995,Mechanical Engineering,doi:10.15781/T2GT5G157,http://hdl.handle.net/2152/69883,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'nanostructuring', 'powder reprocessing']",Selective Laser Sintering Preparation and Tribological Testing of Nanostructured Tungsten Carbide-Cobalt Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1c494f2-22bb-4555-b9e8-2880799a67c8/download,,"This paper describes the results to date ofresearch done to compare and contrast the
tribological properties ofnanostructured tungsten carbide-cobalt composites consolidated by
selective laser sintering (SLS) and conventional grain size composites ofthe same chemical
composition consolidated by conventional commercial methods. The powder preprocessing and
selective laser sintering methods will briefly be described. The tribological testing methods will be
discussed, and the tribological properties ofthe selective laser sintered and commercially
consolidated materials will be compared. It will be seen that the nanosized WC-Co composites
have far superior harness and wear resistance compared to their microsized counterparts.",,,,,,
"['Shi, Dongping', 'Gibson, Ian']",2019-03-11T16:31:43Z,2019-03-11T16:31:43Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73579', 'http://dx.doi.org/10.26153/tsw/721']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Selective Laser Sintering']",Selective Laser Sintering Process Management Using a Relational Database,Conference paper,https://repositories.lib.utexas.edu//bitstreams/915a2f6d-dca5-4334-8ccb-fb794ee842c5/download,,"With more and more materials used in the Selective Laser Sintering (SLS) process, it is
becoming necessary to use a database to manage the process efficiently. In this paper, a
relational database for the SLS process is described. The database includes powdered material
data, sintering parameters, machine characteristics, mechanical properties and surface quality of
prototypes. Use ofthis database will make it is easy to store and retrieve processing information
and make decisions for planning the SLS. This paper will go on to describe how the database
can be extended to include other RP technologies.",,,,,,
"['Weiss, Wendy', 'Bourell, D.L.']",2018-04-17T18:40:33Z,2018-04-17T18:40:33Z,1991,Mechanical Engineering,doi:10.15781/T2G737M79,http://hdl.handle.net/2152/64350,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'intermetallic', 'metallographic techniques', 'x-ray powder']",Selective Laser Sintering to Produce NI-SN Intermetallics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef4f9387-f6cf-4f92-98b2-0ff04e053922/download,,"A model system has been employed to investigate .the use of selective laser sintering (SLS) with
a post-processing step to produce a compound having different properties than the precursor
powders. The powder mixture examined consisted of95% (59% Ni and 41%8n) plus 5% ZnC12.
This weight fraction of nickel and. tin produces. the intermetallic compound Ni3Sn upon equilibrium
annealing. ZnCl2 was used as a wetting agent. Parts were fabricated using SLS and were then
post-process annealed to create the intermetallic. Metallographic techniques and x-ray powder
diffraction were used.to characterize the parts before and after annealing.",,,,,,
"['Khoshnevis, Behrokh', 'Gao, Xiang', 'Barbara, Brittany', 'Nouri, Hadis']",2021-11-04T15:30:09Z,2021-11-04T15:30:09Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89986', 'http://dx.doi.org/10.26153/tsw/16907']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective separation shaping', 'additive manufacturing', 'cementitious', 'composite']",Selective Separation Shaping (SSS) – Large-Scale Fabrication Potentials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2cfbfca-d7f5-4ef0-ae4a-1fe5fc7f21dc/download,University of Texas at Austin,"Selective Separating Shaping is a new additive manufacturing technique which is
capable of processing polymeric, metallic, ceramic and composites including cementitious
materials. In earlier experiments the capabilities of SSS in making metallic and ceramic
parts have been demonstrated. The focus of the research reported in this paper has been on
exploration of capabilities of SSS for creation of large-scale cementitious composite parts.
A prototype machine has been used to create specimens made of regular construction
cement (lime based), Sorel cement (magnesia based) and gypsum based composites. The
fabrication results, surface quality and flexural strength for these experiments are
presented.",,,,,,
"['Nouri, H.', 'Khoshnevis, B.']",2021-11-04T15:26:46Z,2021-11-04T15:26:46Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89985', 'http://dx.doi.org/10.26153/tsw/16906']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['selective separation shaping', 'polymeric parts', 'nylon', '3D printing']",Selective Separation Shaping of Polymeric Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6d5728ab-b926-4b27-b3c4-aff124eede74/download,University of Texas at Austin,"Additive manufacturing (AM), or 3D printing has enjoyed a recent surge of attention over the past decade.
AM is a process in which digital 3D design data is used as input to build physical objects by combining
sequence layers of material. By increasing demand in use of additive manufacturing for fabrication of end-user
parts, there is considerable interest in developing new techniques which can offer high quality customized parts
at low cost. Selective Separation Shaping (SSS) is a new AM technology developed with the goal of fabricating
low cost, high resolution 3D parts. The main advantage of SSS is that this process enables building fully
functional pieces without the need of any intermediate binder or high cost laser operation. This process has been
primarily applied to metallic, and ceramic materials and test cases were successfully built. There has been no
study on fabrication of parts using polymeric material and the goal of this research is to examine successful
fabrication of polymer parts. Nylon 6,6 has been used as starting base material and several test cases were
fabricated to identify key factors in success of this process. Different classes of nylon are studied to achieve
better understanding of material properties on success of fabrication and achieve an effective binding between
layers. Finally, 3D printed parts built by SSS are presented.",,,,,,
"['Zhang, Jing', 'Khoshnevis, Behrokh']",2021-10-19T17:52:08Z,2021-10-19T17:52:08Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89309,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Selective Separation Sintering', 'Additive Manufacturing', 'ceramics', 'metal']",Selective Separation Sintering (SSS) A New Layer Based Additive Manufacturing Approach for Metals and Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11e1d9dd-64b8-485b-8bd1-26dfcc130b88/download,University of Texas at Austin,"Selective Separation Sintering (SSS) is a powder layer based Additive Manufacturing
approach. SSS can fabricate high temperature ceramic and metallic parts at comparatively
lower cost with high quality. In the printing process a dry powder of higher sintering temperature
is deposited into the base material which makes up the part. The inserted powder defines the
boundary of the part and separates the part from its surroundings. When printing of all layers is
completed the deposited dry powder serves as a separation coating which defines the shape of
the part. In the sintering process the base material is sintered into a solid part while the
separation coating remains as loose powder. The part is then separated from the surrounding
area at the separation coating surfaces, and is post processed if necessary. Preliminary results
have proven the capability of SSS in successfully printing ceramic and metallic parts. Future
experiments are planned for improving the process resolution.",,,,,,
"['Khoshnevis, Behrokh', 'Zhang, Jing']",2021-10-28T20:44:54Z,2021-10-28T20:44:54Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89696,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective separation sintering', 'SSS', 'sintering', 'powder deposition', 'additive manufacturing']",Selective Separation Sintering for Metallic Part Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c5887cd-765b-484d-8a1d-563202856090/download,University of Texas at Austin,"Selective Separation Sintering (SSS) is a powder layer based additive manufacturing
approach. In the printing process a dry powder of higher sintering temperature is deposited into
the base material which makes up the part. The inserted powder defines the boundary of the
part and separates the part from its surroundings. A post sintering of the part is carried out in
the furnace where the base material is sintered and the inserted powder remain loose due to its
higher sintering temperature. The part is separated from the surrounding redundant material
along the loose inserted powder region. A stable deposition rate of S-powder is the key for
generating parts of easy separation and smooth surface. Factors that affect the flow rate are
analyzed and the analyzed results are implemented to stabilize the process. With the progress
in powder deposition rate control, bronze parts have been fabricated which demonstrate good
quality.",,,,,,
"['Bournias-Varotsis, A.', 'Friel, R.J.', 'Harris, R.A.', 'Engstrom, D.']",2021-11-01T21:59:46Z,2021-11-01T21:59:46Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89771,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['aluminum foils', 'insulating layer', 'embedded electronic circuits', 'electronic circuits', 'anodic aluminum oxide', 'ultrasonic additive manufacturing']",Selectively Anodised Aluminum Foils as an Insulating Layer for Embedding Electronic Circuitry in a Metal Matrix via Ultrasonic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/376e25f9-8bfe-4fd2-b2fc-9e0201334c25/download,University of Texas at Austin,"Ultrasonic Additive Manufacturing (UAM) is a hybrid Additive Manufacturing (AM)
process that involves layer-by-layer ultrasonic welding of metal foils and periodic machining to
achieve the desired shape. Prior investigative research has demonstrated the potential of UAM for
the embedding of electronic circuits inside a metal matrix. In this paper, a new approach for the
fabrication of an insulating layer between an aluminium (Al) matrix and embedded electronic
interconnections is presented. First, an Anodic Aluminium Oxide (AAO) layer is selectively grown
onto the surface of Al foils prior to bonding. The pre-treated foils are then welded onto a UAM
fabricated aluminium substrate. The bonding step can be repeated for the full encapsulation of the
electronic interconnections or components. This ceramic AAO insulating layer provides several
advantages over the alternative organic materials used in previous works.",,,,,,
"['Crane, N.B.', 'Tuckerman, J.', 'Nielson, G.N.']",2021-09-30T20:25:31Z,2021-09-30T20:25:31Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88296', 'http://dx.doi.org/10.26153/tsw/15237']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'biological growth', 'performance benefits', 'performance challenges', 'self-assembly errors', 'miniature thermoelectric devices', 'microscale photovoltaic cells']",Self Assembly as an Additive Manufacturing Process: Opportunities and Obstacles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f41f01b8-ea68-4f27-87b7-8cc83650f350/download,University of Texas at Austin,"While additive manufacturing processes typically integrate functionally identical building
blocks, biological growth depends on the precise assembly of molecular building blocks to
achieve the remarkable functionality observed in living systems. This paper considers potential
performance benefits and challenges of producing systems by controlled assembly of functional
components. The work will consider the impact of self-assembly errors in two energy
applications: miniature thermoelectric devices and microscale photovoltaic cells. In both, high
performance is possible by assembling microscale components. While assembly errors can
reduce system performance, performance models show that high levels of system performance
can be achieved through system design and/or self-assembly process control.",,,,,,
"['Nassar, A.R.', 'Spurgeon, T.J.', 'Reutzel, E.W.']",2021-10-12T21:51:09Z,2021-10-12T21:51:09Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88750', 'http://dx.doi.org/10.26153/tsw/15684']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['defect detection', 'directed-energy additive manufacturing', 'additive manufacturing', 'metals', 'optical emission spectroscopy']",Sensing Defects during Directed-Energy Additive Manufacturing of Metal Parts using Optical Emissions Spectroscopy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e487fbdf-212a-42c5-993f-bd58edc0a857/download,University of Texas at Austin,"Critical components produced via additive manufacturing must be free of unwanted defects.
While defects may be detectable after deposition using nondestructive testing techniques,
detecting defects during the deposition process offers many benefits: it may enable users to
interrupt deposition to repair the part, or to abort deposition to minimize further loss of time and
material. Here, we present a method for real-time defect detection during directed-energy
additive manufacturing of metals. The method utilized optical emission spectroscopy and a
custom-built data acquisition and control infrastructure. It was implemented on a LENS MR-7
machine, and employed during manufacturing of Ti-6Al-4V components in which defects were
intentionally introduced. Emission spectra were correlated with defect locations, determined via
computed tomography and metallographic cross-sectioning. Preliminary results indicated that
defect formation was correlated with atomic titanium (Ti I) and Vanadium (V I) emissions and
that measurement of the line-to-continuum ratio for line emissions could be used for defect
detection. Based on these findings, sensing strategies for defect detection and, potentially, in-situ-defect repair may be realizable.",,,,,,
"['Fan, Zhiqiang', 'Phatak, Kaushik', 'Liou, Frank']",2020-02-21T16:04:29Z,2020-02-21T16:04:29Z,8/30/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80065', 'http://dx.doi.org/10.26153/tsw/7087']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Laser Metal Deposition,Sensitivity Analysis of Process Parameters in Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea8beb7e-d6df-49e0-82a2-36fd784c2b77/download,,"In laser cladding with powder injection process, process output parameters, including
melt pool temperature and melt pool dimensions, are critical for part quality. This paper uses
simulation and experiments to investigate the effect of the process input parameters: laser power,
powder mass flow rate, and scanning speed on the output parameters. Numerical simulations and
experiments are conducted using a factorial design. The results are statistically analyzed to
determine the significant factors and their interactions. The simulation results are compared to
experimental results. The quantitative agreement/disagreement is discussed and further research is
outlined.",,,,,,
"['Vasudevarao, Bharath', 'Natarajan, Dharma Prakash', 'Henderson, Mark', 'Razdan, Anshuman']",2019-09-23T15:55:41Z,2019-09-23T15:55:41Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75946', 'http://dx.doi.org/10.26153/tsw/3045']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Parameter,Sensitivity of RP Surface Finish to Process Parameter Variation 251,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d1a23107-9fba-4ba0-8e8c-7a9156e975cc/download,,"In the rapid prototyping process, surface finish is critical as it can affect the part accuracy, reduce the post processing costs and improve the functionality of the parts. This paper presents an experimental design technique for determining the optimal surface finish of a part built by the Fused Deposition Modeling (FDM) process. The design investigates the effect of the parameters; build orientation, layer thickness, road width, air gap and model temperature on the surface finish. Experiments were conducted using a fractional factorial design with two levels for each factor. The results are statistically analyzed to determine the significant factors and their interactions. The significant factors, their interactions and the optimum settings are proposed.",,,,,,
"['Liravi, Farzad', 'Das, Sonjoy', 'Zhou, Chi']",2021-10-19T15:36:53Z,2021-10-19T15:36:53Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89302,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['bottom-up stereolithography', 'bottom-up additive manufacturing', 'finite element analysis', 'separation force', 'cohesive delamination', 'optimization']",Separation Force Analysis Based on Cohesive Delamination Model for Bottom-Up Stereolithography Using Finite Element Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/65027874-7aaf-48f6-bc28-9b61f146b12b/download,University of Texas at Austin,"Bottom-up (constrain-surface) Additive Manufacturing (AM) systems have been widely used in
industry. Compared to traditional open-surface AM technology, properties like better vertical resolution, higher
material filling rate, less production time, and less material waste make bottom-up AM technology a suitable
candidate for fabrication of complex three dimensional materials with high accuracy. However during the
pulling up stage, the substantial force generated between the formed part and the material container has high
risk of breaking the part and therefore reduces the process reliability. In this paper, an optimization-based
method is developed to model bottom-up AM process using finite element analysis (FEA). The FEA model is
developed using ABAQUS to model the behavior of the cohesive delamination at the interface of the formed
part and a hyper-elastic intermediate which has been used to reduce the pulling up force. An optimization
model is also established to evaluate the cohesive stiffness parameters that cannot be calculated directly from
closed formulas or mechanical tests. The results of this work will be used to develop an adaptive closed-loop
mechanics-based system to control the pulling up process and achieve a reliable technology.",,,,,,
"['Ljungblad, U.', 'Hultman, A.']",2021-09-30T13:40:06Z,2021-09-30T13:40:06Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88246', 'http://dx.doi.org/10.26153/tsw/15187']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'orthopedic implants', 'statistical process control']",Serial Production with EBM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6c0233d8-e8d8-4ef6-9199-7a6dc2248fb6/download,University of Texas at Austin,,,"Moving from prototyping to production is a major challenge for the additive
manufacturing industry. It requires a robust and reliable technology having high and
verifiable repeatability. The transition into production is not possible without the
technology being capable of sustaining a high product quality as well as productivity in
par or better than traditional manufacturing.
Electron Beam Melting (EBM) has since 2007, been used for manufacturing of CE-certified standard orthopedic implants with more than 20’000 units produced in several
EBM systems. High productivity combined with process stability has been key factors for
this application to emerge. Added product value in form of engineered surface porosity
has been vital to promote the step into serial production.
Development of EBM has been focused on system reliability, process stability,
material quality, productivity and means for process validation to reach proven
requirements for production. Statistical process control (SPC) has been a very powerful
tool to carry out this development in an efficient way.",,,,
"['Manzur, Tariq', 'Roychoudhuri, Chandra', 'Marcus, Harris']",2018-11-14T19:49:11Z,2018-11-14T19:49:11Z,1996,Mechanical Engineering,doi:10.15781/T21V5C03W,http://hdl.handle.net/2152/70258,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD/CAM', 'SLS', 'SFF']",SFF Using Diode Lasers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/28b8533e-977f-419a-b34d-8c1c12a9841f/download,,"Rapid prototypings using direct selective laser sintering (SLS) ofmetal/ceramic powders
have a great potential for design and fabrication of near net shape ofmetal/ceramic parts.
At presents CO2, Nd:YAG and Excimer are the only possible solutions for the heavy duty
manufacturing applications. At the University ofConnecticut, researchers advanced the
concept ofrapid prototyping and other desk top manufacturing tasks such as welding,
sintering, drilling, marking, soldering of electronic components, face hardening ofmetal
and other materials applications by the use ofhigh power diode lasers.
Utilizing SLS techniques and approaches designed to harness the full potential of diode
lasers, computer controlled sintering system was developed. The system is capable of
producing complex three dimensional shapes ofmetal/ceramic parts from CAD/CAM
solid model data files. In the paper direct sintered Fe-Bronze parts using high power laser
diodes has been demonstrated. The system comprises ofhigh power laser diodes (25 W
cw, A=980 nm and 60 W pulse or cw, A=81 0 nm), beam scanning systems, atmospheric
controlled chamber, and CAD/CAM software.",,,,,,
"['Xu, Anping', 'Shaw, Leon L.']",2020-02-17T14:19:56Z,2020-02-17T14:19:56Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79995', 'http://dx.doi.org/10.26153/tsw/7020']",eng,2004 International Solid Freeform Fabrication Symposium,Open,"['functionally graded materials', 'Equal distance offset', 'Solid freeform fabrication']",SFF-Oriented Modeling and Process Planning of Functionally Graded Materials Using a Novel Equal Distance Offset Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d293c4f7-1d4b-4a1e-9562-0a4339a57a01/download,,"This paper deals with the modeling and process planning of solid freeform fabrication
(SFF) of 3D functionally graded materials (FGMs). A novel approach of representation and
process planning of FGMs, termed as equal distance offset (EDO), is developed. In EDO, a
neutral arbitrary 3D CAD model is adaptively sliced into a series of 2D layers. Within each
layer, 2D material gradients are designed and represented via dividing the 2D shape into
several sub-regions enclosed by iso-composition contours. If needed, the material
composition gradient within each of sub-regions can be further determined by applying the
equal distance offset algorithm to each sub-region. Using this approach, an arbitrary-shaped
3D FGM object with linear or non-linear composition gradients can be represented and
fabricated via suitable SFF machines.",,,,,,
"['Bernitsas, Michael M.', 'Suryatama, Danet', 'Byungsik, Kang', 'Dale, G. Karr']",2018-10-03T15:59:04Z,2018-10-03T15:59:04Z,1994,Mechanical Engineering,doi:10.15781/T2R78676V,http://hdl.handle.net/2152/68656,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['LEAP Theory', 'selective laser sintering', 'Solid free-form fabrication']",Shape and Topology Structural Redesign by Large Perturbations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19cd8728-dc10-4270-a38f-4728e445b56d/download,,"The ultimate goal in concurrent engineering of structures is to achieve simultaneously in the
design stage the following objectives: (1) A shape that performs itsfunction, conforms with the
boundary conditions,and can support the external loads. (2) A product with structural integrity,
i.e. with stress levels remaining below acceptable limits. (3) A product with acceptable
performance, e.g. modal dynamics, i.e. with natural frequencies and mode shapes that do not
amplify external dynamic loads; and static, i.e. acceptable deflection. (4) A composite
microstructure that can optimally satisfy the above topology/ shape, load, and performance
constraints. (5) A microstructurefabrication process that efficiently produces the above optimal
structure. The purpose of our ONR funded project is to address the complete problem in
concurrent structural design by further developing the LargE Admissible Perturbations (LEAP)
theory which is being developed at the University of Michigan since 1983, and combiningit with
micromechanicsconstitutive equations. At the fabrication end, the Selective Laser Sintering (SLS)
process will be simulated so that the SLS variables are defined as the final product of the
concurrent structuraLdesign optimization process. LEAP theory -- as implemented in Code
RESTRUCT (REdesign of STRUCTures) -- produces the final design without trial and error or
repeated Finite Element Analyses (FEAs), thus, shortening the redesign process and contributing
to rapid prototyping.",,,,,,
"['Merz, R.', 'Prinz, F.B.', 'Ramaswami, K.', 'Terk, M.', 'Weiss, L.E.']",2018-09-26T15:47:56Z,2018-09-26T15:47:56Z,1994,Mechanical Engineering,doi:10.15781/T2BK1781C,http://hdl.handle.net/2152/68579,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'CAD/CAM', 'SFF', 'Shape Deposition']",Shape Deposition Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ddbfacb-0827-4a15-9fe6-3a149ff24c7e/download,,"One challenge for solid freeform fabrication has been to develop the capability to directly
create functional metal shapes which are dense, metallurgically bonded, geometrically accurate
and with good surface appearance. Shape Deposition is a manufacturing paradigm which attempts
to address these issues. It incorporates the advantages of several processes including solid freeform
fabrication (complex geometries, rapidly planned), 5-axis CNC machining (accuracy,
smooth surfaces), shot-peening (for stress relief) and 'microcasting' (a high-performance, weldbased
material deposition process). These processes are integrated within a CAD/CAM system
using robotic automation. This paper will present the current research in this effort.",,,,,,
"['Weiss, L.', 'Prinz, F.', 'Neplotnik, G.', 'Padmanabhan, K.', 'Schultz, L.', 'Merz, R.']",2018-11-08T19:39:06Z,2018-11-08T19:39:06Z,1996,Mechanical Engineering,doi:10.15781/T2MG7GF74,http://hdl.handle.net/2152/69916,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SDM', 'SFF', 'manufacturing process']",Shape Deposition Manufacturing of Wearable Computers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85ac1852-f05c-402c-9911-5f9ff302b0a1/download,,"Shape Deposition Manufacturing (SDM) is a solid freefrom fabrication methodology which
can fabricate heterogeneous structures, i.e., multi-material structures with embedded components.
One application is to build-up electromechanical devices such as conformally shaped computer
packages with embedded electronics. The goal is to be able to quickly design and manufacture, in
small lots, personalized, rugged units for specialized applications. One example, which is
described in this paper, is the manufacture of an underwater computer, the 'Frogman', which is
built-up in layers of polyurethane.",,,,,,
"['Zhou, Wenchao', 'Loney, Drew', 'Fedorov, Andrei G.', 'Degertekin, F. Levent', 'Rosen, David W.']",2021-10-04T21:44:23Z,2021-10-04T21:44:23Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88358', 'http://dx.doi.org/10.26153/tsw/15297']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['ink-jet printing', 'droplet deposition', 'droplet impact']",Shape Evolution of Droplet Impingement Dynamics in Ink-Jet Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1346c739-c744-46a4-90c9-d9e0aece91b4/download,University of Texas at Austin,"Ink-jet printing enables more efficient, economic, scalable manufacturing for a wide variety of materials
than other traditional additive techniques. The impact of droplets onto a substrate is critical for accuracy control
and optimization of the droplet deposition process. However, most previous research about droplet impact
focused on the spreading radius of the droplet, which does not provide enough information for manufacturing
purposes. This paper presents new methods to model and characterize droplet shape change during impact so
that the droplet deposition process can be optimized to build desired geometries. A validated numerical model is
used to study the shape change of the droplet impingement on a solid surface. A dimensional analysis is
conducted to reduce the number of parameters of the impact conditions by matching Reynolds, Weber, and
Froude numbers as well as possible. In addition, a new method of characterizing droplet shape is presented that
measures its similarity to a desired shape. The shape evolution of a wide range of impact conditions is simulated
with the validated numerical model using both physical and dimensionless quantities. The effects of the
dimensionless numbers on the shape evolution are examined and analyzed. Successive multiple droplets impact
is also simulated.",,,,,,
"['Utela, B.', 'Anderson, R.', 'Kuhn, H.', 'Ganter, M.']",2020-03-09T15:14:25Z,2020-03-09T15:14:25Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80194', 'http://dx.doi.org/10.26153/tsw/7213']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Three Dimensional Printing,Shape Training of Nitinol Wire Using Three-Dimensional (3DP) Fixtures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/401afcbd-4a4f-4ae5-ab95-86c439242682/download,,"The presented research focuses on work done at the University of Washington on
process development for the training of nitinol shape memory alloy wire using Three
Dimensional Printing (3DP). Fixtures are created using the commercial stainless steel
printing system produced by Ex One. Superelastic nitinol wire is set by restraining the
wire in a fixture and thermal processing. A two dimensional test array was designed and
fabricated to examine the effects of fixture curvature on the final wire shape. Three
dimensional coils and spheres were created to demonstrate the potential of this process
for more complicated shapes.",,,,,,
"['Yang, Li', 'Harrysson, Ola', 'West, Harvey', 'Cormier, Dennis']",2021-10-21T19:14:10Z,2021-10-21T19:14:10Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89426,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['auxetic structure', 're-entrants', 'shear properties', 'electron beam melting']",Shear Properties of the Re-Entrant Auxetic Structure Made via Electron Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ae906d6b-cffe-4744-bf25-af438bcb82be/download,University of Texas at Austin,"While the tensile/compressive mechanical properties of the re-entrant auxetic cellular structure
have been relatively well modeled, their shear properties including the shear modulus and shear
strength have not been investigated. This paper focuses on the analytical modeling of the shear
properties of this auxetic structure utilizing beam analysis. The modeling results were further
compared with results from both simulation and experimentation. It was found that in addition
to the effective length reduction effect, the size effect also becomes significant for the shearing
of this re-entrant auxetic structures. Due to the size effect, it was expected that the re-entrant
auxetic structure could not be effectively homogenized based on the developed analytical
property model, and additional design factors must be considered in the future.",,,,,,
"Steinchen, W.",2018-11-02T16:53:55Z,2018-11-02T16:53:55Z,1995,Mechanical Engineering,doi:10.15781/T2891294T,http://hdl.handle.net/2152/69340,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['strain analysis', 'vibration isolation', 'optimization']",Sheareography - a Practical Optical Testing and Measuring Method,Conference paper,https://repositories.lib.utexas.edu//bitstreams/27b4222f-ea28-4dc0-995e-6aa491a4f66c/download,,"Shearography is a laser optical method which is suited for either nondestructive testing or for
strain analysis. Contrary to holography which measures surfach displacements, shearography
measures derivatives of surface displacements. Since strains are functions of displacement
derivatives, shearography allows strains to be determined without numerical differentiating
displacement data. Defects in object normally create strain concentrations; it is easier using
shearography to correlate defects with strain anomalies rather than displacement anomalies
applying holography. Furthermore, rigid body motions do not produce strain, thus shearography
is insensitive against such motions and does not need adopting any particular device for vibration
isolation. It is an industrial tool suited very well for the following ares:
1. strain measurement and strain analysis
2. nondestructive testing and quality assurance system
3. optimization ofmachine parts and structures of any material",,,,,,
"['Kletetzka, I.', 'Klippstein, H.', 'Sural, I.', 'Schmid, H.-J.']",2023-03-29T16:16:58Z,2023-03-29T16:16:58Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117676', 'http://dx.doi.org/10.26153/tsw/44555']",eng,2022 International Solid Freeform Fabrication Symposium,Open,laser sintering,Shelf Life of Polyamide 12 (PA2200) Laser Sintering Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0240d80f-fdb1-403d-8551-46ba427136d1/download,,"It is a very well-known fact that polyamide powders age during processing in laser 
sintering. Therefore, the recycling rate of used powder is typically limited to around 50 % and it 
has to be mixed with new, virgin powder, before the next build job can be started. The aging of the 
polymer powder between its production and processing, in contrast, has hardly been investigated 
so far and has received little attention. In order to investigate the effects of storage time, optical, 
thermal and rheological tests were carried out on two batches of PA2200 powder, which had been 
stored for 5.5 and 6.5 years respectively. Compared to freshly produced powders, aging effects 
were clearly visible.",,,,,,
"['Yao, W. L.', 'Leu, Ming C.']",2019-02-25T17:45:13Z,2019-02-25T17:45:13Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73477', 'http://dx.doi.org/10.26153/tsw/627']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Investment Casting']",Shell Cracking In Investment Casting with Laser Stereolithography Patterns,Conference paper,https://repositories.lib.utexas.edu//bitstreams/38b318eb-09a7-4930-b162-482f82a5ceef/download,,"This paper presents an investigation of ceramic shell cracking during the burnout process
in investment casting with internally webbed laser stereolithography patterns. We hypothesize
that shell cracking will occur when the rupture temperature of the ceramic shell is lower than
both the glass transition temperature of the pattern material and the web· link buckling
temperature. The hypothesis is validated by our experimental observations which confirm the
numerical predictions from our fillite element analysis. This provides a basis for design of the
internal web geometry of a lithography pa.tternand evaluation ofthe burnolltprocesswithsuch a
pattern. We show the shell cracking and web link buckling temperatures to be functiollsofthe
pattern geometry (including the cross~sectional dimensions and span length of the web link) and
the shell thickness.",,,,,,
"['Dilip, J.J.S.', 'Anam, Md Ashabul', 'Pal, Deepankar', 'Stucker, Brent']",2021-10-28T21:11:22Z,2021-10-28T21:11:22Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89702,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'selective laser melting', 'alloy IN625', 'single track deposits']",A Short Study on the Fabrication of Single Track Deposits in SLM and Characterization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66e18862-6618-4434-b47e-ea737d9fb564/download,University of Texas at Austin,"The present investigation is focused on fabrication of single track deposits, with multiple laser
power and scan speed combinations to turn understanding their effect on the formation of the
melt pool. In this study alloy, IN625 powder from EOS was used to produce single track
deposits. Surface morphology and dimensions of single track deposits were characterized using
SEM. The cross-section of the single track deposits was studied, and the geometrical features of
melt pools were evaluated. The results indicate that melt pool characteristics provide significant
information that is helpful for process parameters selection. These single track experiments will
be being extended to fabricate samples with multiple layers in the future study. This approach of
investigating single track deposits, when used to narrow down the window of process parameters
can provide a path to speed up the tedious and time-consuming experiments for optimization of
process parameters.",,,,,,
"['McIntosh, Joseph J.', 'Danforth, Stephen C.', 'Jamalabad, Vikram R.']",2018-11-29T20:20:48Z,2018-11-29T20:20:48Z,1997,Mechanical Engineering,doi:10.15781/T2513VG0Q,http://hdl.handle.net/2152/70338,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SLS']",Shrinkage and Deformation in Components Manufactured by Fused Deposition of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ccc53e8-a835-4750-9431-5a35f3953900/download,,"Fused Deposition of Ceramics (FDC) presents a new processing technique that may contribute
to anisotropic shrinkage and deformation, which are critical issues in the manufacture of
ceramic components. The aim ofthis study is to identify and quantify key FDC parameters and
their influence on shrinkage and deformation. The study was divided into two focus areas. The
first was the effect ofthe FDC build parameters on the shrinkage of ceramic parts. The second
focused on the interaction of the FDC build process with the geometrical features of a part. A
series of experimental design techniques have been implemented in order to gain a thorough
understanding of said parameters, as well as any possible interactions between parameters
Studies have been conducted across each processing step, from the green manufacture of the
part, through binder removal, and sintering. The data and knowledge gained from these
experiments will allow us to redesign the original CAD component files to compensate for the
shrinkage and deformation encountered when using the FDC technique",,,,,,
"['Bhargava, P.', 'Bandyopadhyay, A.', 'Rangarajan, S.', 'Qi, G.', 'Dai, C.', 'Wu, S.', 'Danforth, S.', 'Safari, A.']",2018-12-05T19:53:23Z,2018-12-05T19:53:23Z,1997,Mechanical Engineering,doi:10.15781/T2WS8J63V,http://hdl.handle.net/2152/71407,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['FDC', 'heating schedule']","Shrinkage, Weight Loss and Crack Prevention During Binder Burn Out of Components Produced"" by Fused Deposition of Ceramics (FDC)",Conference paper,https://repositories.lib.utexas.edu//bitstreams/483638ce-bfc2-44a1-9110-444bbb302e94/download,,"In the present study the sequential stages ofthe previously established binder bum out (BBO)
route were characterized by obtaining precise shrinkage and weight loss measurements from
interrupted runs. A DoE (Design of Experiments) approach was adopted to systematically
investigate the effect of process variables; such as the heating rates during critical segments, part
dimensions and environment (flowing nitrogen vs vacuum) on the shrinkage, weight loss and
cracking during binder bum out. A stepwise TGA was performed to study the effect of ramp rate
and dwell time on the kinetics of binder bum out, and an experiment was conducted to determine
optimum wicking conditions. The results from this study have been used to maximize the weight loss
and minimize the cracking during binder bum out cycle for FDC parts with different sizes.",,,,,,
"['Stierlen, Peter', 'Schanz, Peter', 'Eyerer, Peter']",2019-02-26T20:39:02Z,2019-02-26T20:39:02Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73499', 'http://dx.doi.org/10.26153/tsw/649']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['high density ceramic structure', 'carbon binding structure']",Si/SiC-Ceramic low process shrinkage - high temperature material for the Laser Sinter process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8a8b6ba-df71-46ea-96e1-5bc6ad0c4a9c/download,,"Actual RP-systemsare very limited in producing adequate ceramic prototypes. In the
presented process, the SiC..green part manufacturing bythe laser sintering process in combination
with special postprocessing allows the fast production of SUSiC prototypes. A mixture of SiC
powder and a reactive polymer binder system is used in the Laser Sinter process. In the following
postprocessing the porous green part has to be .infiltrated with a precursor resin, carbonised and
finally infiltrated withimolten silicon.•Incontrast to cold isostatic moulding or slip casting the
shrinkage is very low (2-4 0/0).• Experiments with suitable materials/and process conditions were
successful. This paper will show the state of and the possible further investigation into process.",,,,,,
"['Stierlen, Peter', 'Eyerer, Peter']",2019-03-12T20:01:05Z,2019-03-12T20:01:05Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73608', 'http://dx.doi.org/10.26153/tsw/750']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['precursor·resin', 'silicon']",Si/SiC-Ceramic Prototypes via LS2I-Process (Liquid Silicon Infiltration of Laser Sintered C-SiC Parts),Conference paper,https://repositories.lib.utexas.edu//bitstreams/c4061c09-873d-4fd5-9b93-2d9d02d66fa5/download,,"The liquid silicon infiltration of laser sinteredC-~iC parts (LS2
I) is solidfreeform
fabrication technique which allows the production of complexshapedSi/SiC prototypes. A
mixture of SiC powder and reactive polymer binder isused in the las~r sinteringprocessto
generate a porous green part. In the\postprocessing, the porous green part structure has to be
infiltrated with a.precursor·resin, carbonised and finally·.infiltrated•. with molten silicon. The
infiltrated silicon reacts with the residualcarbontobuild~~SiC.Results generated by the use of
reduced primary particle sizes as well asaltemative infiltration materials and the use of other·RPtechniquesfor the green partfabrication will be discussed in this paper.",,,,,,
"['Melvin III, Lawrence S.', 'Beaman Jr., Joseph J.']",2018-11-08T15:39:49Z,2018-11-08T15:39:49Z,1995,Mechanical Engineering,doi:10.15781/T2FX74H89,http://hdl.handle.net/2152/69891,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['powder application', 'bed density experiment', 'sieve feed system']",A Sieve Feed System for the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/303042ca-d234-414d-aeab-1d1d1438758e/download,,"A sieve feed system has been designed for use with the Selective
Laser Sintering process. The sieve feed system uses
electrostatic charge to help apply polymer powder to a green
powder bed. The sieve feed system was found to help the
application of polymer powder as measured by a 10 to 15%
increase in final part density. The sieve feed system has
many potential applications, including material property design,
and material mixing during the sintering process.",,,,,,
"['Taft, Douglas', 'Ogale, Amod', 'Paul, Frank', 'Hunt, Elaine', 'Ahzi, Said']",2018-12-05T17:11:39Z,2018-12-05T17:11:39Z,1997,Mechanical Engineering,doi:10.15781/T2XS5K333,http://hdl.handle.net/2152/71399,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['StereoLithography', 'solid models']",Silica Filled Resins for Rapid SLA Tools,Conference paper,https://repositories.lib.utexas.edu//bitstreams/507d2a5d-7432-4538-905c-1d2adb898d06/download,,"A stable silica /SL epoxy resin suspension has been developed at Clemson
University. It has been processed to make parts in a commercial StereoLithography
Apparatus (SLA). Results oftesting show that the composite material has a higher
modulus and increased abrasion resistance over the neat epoxy resin. An injection
molding die has been made with the reinforced resin in the SLA and tested.",,,,,,
"['Mi, Jian', 'Gillespie, Josh', 'Johnson, Ryan W.', 'Bondi, Scott N.', 'Lackey, W. Jack']",2019-11-21T18:22:08Z,2019-11-21T18:22:08Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78556', 'http://dx.doi.org/10.26153/tsw/5612']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Silicon Carbide,Silicon Carbide Growth Using Laser Chemical Vapor Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fb3821c8-ce1f-48bc-b2cc-b8e38d00f41a/download,,"Silicon Carbide (SiC) has been grown from methyltrichlorosilane (MTS) and
hydrogen using the Georgia Tech Laser Chemical Vapor Deposition (LCVD) system. A
morphology study of LCVD-SiC fibers and lines was completed. Graphite and single
crystal silicon were used as the substrates. In order to provide guidance to future growth
of SiC, thermodynamic calculations for the C-H-Si-Cl system were performed using the
SOLGASMIX-PV program.",,,,,,
"['Vail, N.K.', 'Barlow, J.W.', 'Marcus, H.L.']",2018-05-03T19:06:51Z,2018-05-03T19:06:51Z,1993,Mechanical Engineering,doi:10.15781/T25X25W7S,http://hdl.handle.net/2152/65059,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'SLS', 'Department of Chemical Engineering', 'Center for Materials Science and Engineering', 'Silicon Carbide', 'Encapsulation', 'Polymer', 'Composites']",Silicon Carbide Preforms for Metal Infiltration by Selective Laser Sintering™ of Polymer Encapsulated Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de3d507b-e987-44c3-bf3d-f1fa765acc96/download,,"A polymer encapsulated silicon carbide system has been developed for
use with Selective Laser Sintering. Extensive studies with this material
have provided information pertaining to processing and material
parameters which most affect the strengths and densities of resulting
green parts. The important parameters considered were particle size
distribution of the powders, laser scanning conditions, and laser beam
diameter. Simple and complex shapes were easily produced with this
material using optimized parameters. Green objects were infused with
metal by Lanxide using their pressureless infiltration process to produce
both metal matrix and ceramic matrix composites.
(Key Words: Silicon Carbide, Encapsulation, Polymer, Selective Laser
Sintering, Composites).",,,,,,
"['Birmingham, B.R.', 'Tompkins, J.V.', 'Marcus, H.L.']",2018-10-03T18:19:38Z,2018-10-03T18:19:38Z,1994,Mechanical Engineering,doi:10.15781/T22J68P93,http://hdl.handle.net/2152/68669,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['SALDVI', 'selected laser area deposition', 'solid freeform fabrication']",Silicon Carbide Shapes By Selected Area Laser Deposition Vapor Infiltration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/efc3902b-fd12-4374-b248-af1b996d95b1/download,,"Selected Area Laser Deposition Vapor Infiltration (SALDVI) is a unique
combination ofselected area laser deposition, chemical vapor infiltration and layered
powder handling techniques that can be used to fabricate silicon carbide (SiC)/SiC
composite shapes. This paper discusses a SALDVI process under investigation which
selectively infiltrates SiC powder with SiC generated by decomposition of a gas precursor
under a scanned laser beam. A general description of the process, including some of its
inherent advantages is presented. Experimental results which explore beam interaction,
powder size and infiltration time effects are also presented.",,,,,,
"['Flach, Lawrance', 'Chartoff, Richard P.']",2018-10-03T15:36:15Z,2018-10-03T15:36:15Z,1994,Mechanical Engineering,doi:10.15781/T2NG4HB3F,http://hdl.handle.net/2152/68649,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Polymer shrinkage', 'stereolithography', 'Photopolymerization']",A Simple Polymer Shrinkage Model Applied to Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6796957d-2c6b-4a2e-8a76-619c18df2c58/download,,"A simple polymer shrinkage model has been successfully applied to the stereolithography
process. The shrinkage model, which computes specific volume changes from the degree of
conversion of monomer to polymer, incorporates a lag between conversion and shrinkage. An
overall process model used to simulate the stereolithography process was modified by inclusion
of the shrinkage model. Use of the modified stereolithography process model allows prediction
of the shrinkage that might be expected to occur when fabricating a strand of plastic. By varying
the lag between conversion and shrinkage it is shown that faster shrinking resins should exhibit
lower overall shrinkage than slower shrinking resins. This is a direct result of the fact that less
shrinkage occurs after the strand has been scanned for the faster shrinking resins.",,,,,,
"['Karunakaran, K. P.', 'Solanki, P. D.', 'Sahasrabudhe, Onkar S.', 'Pushpa, Vishal', 'Dwivedi, Rajeev', 'Kovacevic, Radovan']",2020-02-24T15:01:18Z,2020-02-24T15:01:18Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80077', 'http://dx.doi.org/10.26153/tsw/7098']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Rapid Prototyping,Simplified Production of Large Prototypes using Visible Slicing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e33460f-7a79-40de-b0ab-8a48375b2318/download,,"Rapid Prototyping (RP) is a totally automatic generative manufacturing
technique based on a “divide-and-conquer” strategy called ‘slicing’. Simple
slicing used on 2.5-axis kinematics of the existing RP machines is responsible for
the staircase error. Although thinner slices will have less error, the slice thickness
has practical limits. Visible Slicing overcomes these limitations. A few visible
slices exactly represent the object. Each visible slice can be realized using a 3- axis kinematics machine from two opposite directions. Visible slicing is
implemented on Segmented Object Manufacturing (SOM) machine under
development. SOM can produce soft large prototypes faster and cheaper with
accuracy comparable to that of CNC machining.",,,,,,
"['Flood, Aaron', 'Liou, Frank']",2021-11-18T17:40:01Z,2021-11-18T17:40:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90442', 'http://dx.doi.org/10.26153/tsw/17363']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['laser beam quality', 'laser beam distance', 'Ti-64', 'aluminum', 'steel', 'blown powder', 'metal additive manufacturing']",Simulated Effect of Laser Beam Quality on the Robustness of Laser-Based AM System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4650a2a1-d050-4fbc-9d8b-be4f91841594/download,University of Texas at Austin,"In many metal AM techniques, a laser is used as the heat source and in some applications, it
can be advantageous to work off of the focal plane. When operating outside of focus, the beam
quality of the laser can have drastic impacts on the ability to manufacture quality parts. This
study investigates the effect of the beam quality and distance from the focal plan on the ability
to deposit Ti-64, aluminum, and steel through the simulation of the blown powder process.",,,,,,
"['Costa, L.', 'Vilar, R.', 'Réti, T.']",2020-02-17T15:03:30Z,2020-02-17T15:03:30Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80004', 'http://dx.doi.org/10.26153/tsw/7029']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Multilayer laser powder deposition,Simulating the Effects of Substrate Pre-Heating on the Final Structure of Steel Parts Built by Laser Powder Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea036650-8ed0-4efa-b3d7-013be6c8ae8e/download,,"Tool steel parts built by laser powder deposition often present a heterogeneous distribution of
properties caused by the complex structural transformations that occur during the deposition
process. A model describing these transformations has been developed. It couples finite element
heat transfer calculations with transformation kinetic theory to predict the final microstructure
and properties of the material and their variation across a laser powder deposited part.
Pre-heating is often used to reduce the residual stresses and the risk of thermal distortion and
cracking. However, this changes the heat transfer conditions and affects the final microstructure
and properties. In this work the proposed model was used to evaluate the effects of substrate preheating on the final hardness distribution. The results show that the final hardness depends
considerably on the initial temperature of the substrate.",,,,,,
"['López, Omar', 'Martínez-Hernández, Uriel', 'Ramírez, José', 'Pinna, Christophe', 'Mumtaz, Kamran']",2021-10-26T18:46:03Z,2021-10-26T18:46:03Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89554,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['Cellular Automata - Finite Element', 'CA-FE', 'AA-2024', 'microstructure', 'selective laser melting']",Simulating the Microstructural Evolution of a Selective Laser Melted AA-2024,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cc17bba6-d9b0-45fb-a1d6-16040789146b/download,University of Texas at Austin,"A two-dimensional Cellular Automata (CA) – Finite Element (FE) (CA-FE) coupled model has
been developed in order to predict the microstructure formed during melting of a powdered AA-2024 feedstock using the Additive Manufacturing (AM) process Selective Laser Melting (SLM).
The presented CA model is coupled with a detailed thermal FE model computing heat flow
characteristics of the SLM process. The developed model takes into account the powder-to-liquid-to-solid transformation, tracks the interaction between several melt pools within a melted track,
and several tracks within various layers. It was found that the simulated microstructures bared a
close resemblance with fabricated AA-2024 SLM samples. With these observed capabilities of the
model, the porosity within a SLM produced part can be predicted, and used to optimise the
fabrication parameters of a sample.",,,,,,
"['Childs, T.H.C.', 'Hauser, C.', 'Taylor, C.M.', 'Tontowi, A.E.']",2019-09-20T18:21:07Z,2019-09-20T18:21:07Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75925', 'http://dx.doi.org/10.26153/tsw/3024']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Sintering,Simulation and Experimental Verification of Crystalline Polymer and Direct Metal Selective Laser Sintering 100,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fcbec39b-777c-4397-a2b2-5382707b4bca/download,,"A previously developed two-dimensional finite element simulation of the SLS of amorphous polymers has been extended to the study of crystalline polymers and metals. For crystalline polymers, three developments have been needed: the treatment of latent heat of melting, the modifying of a viscous densification law to allow for the crystalline fraction of material during melting and, to obtain agreement with experiments, a consideration of the absorption depth of CO2 laser radiation into the powder bed; but the two-dimensional treatment remains sufficient. For metals, a different densification law and three-dimensional modelling have been needed for agreement with experiments on stainless steel powder beds.",,,,,,
"['Kellner, I.N.', 'Zaeh, M.F.']",2021-09-30T19:52:18Z,2021-09-30T19:52:18Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88287', 'http://dx.doi.org/10.26153/tsw/15228']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Additive Layer Manufacturing', '3D inkjet printing', 'polymerization', 'product quality', 'multi-scale simulation models', 'material design', 'process design']",Simulation Models for 3D Inkjet Printing – Material and Process Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4652b1e3-6cec-4a98-b434-05f4dce9f0be/download,University of Texas at Austin,"Due to the ability to produce complex parts with no need for pre-tooling, Additive Layer
Manufacturing (ALM) is a future technology with 3D inkjet printing being one of them. The
latter is based on the polymerization of a liquid dispensed into a powder bed. However, the
special challenges which have to be met here are to increase product quality such as tensile
strength and density on a repeatable base. Consequently multi-scale simulation models were
developed to support material researchers as well as users of the technology in their daily work
and therefore to contribute to process stability and material reliability of 3D printers and their
products.",,,,,,
"['Tikare, Veena', 'Griffith, Michelle', 'Schlienger, Eric', 'Smugeresky, John']",2018-12-07T17:08:46Z,2018-12-07T17:08:46Z,1997,Mechanical Engineering,doi:10.15781/T2GF0NG8W,http://hdl.handle.net/2152/71450,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['microstructures', 'SEM micrograph']",Simulation Of Coarsening During Laser Engineered Net Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b2791c2a-cd9e-465c-9db4-e9969045d610/download,,"Laser Engineered Net_Shaping, otherwise known as LENSTM, is an advanced manufacturing
technique used to fabricate complex near net shaped components directly from engineering solid
models without the use of dies or machining. The ultimate objective ofthis project is to develop
predictive simulation capability which will allow the LENSTM processors to determine fabrication
conditions given the material, shape, and application ofthe final part. In this paper, we will
present an incremental achievement to meeting the ultimate goal, a model capable ofsimulating
the coarsening ofmicrostructural features under the unique thermal history to which a LENSTM
part is subjected during processing. The simulation results show how grains ofvery different
shapes and sizes form within the same deposition line. They also show that relatively minor
changes in the dynamic temperature profile results in microstructures with vastly different
characteristics. The implications ofthis work for LENSTM fabrication is that controlling the
temperature profile is essential to tailoring the microstructure of a component to its application.",,,,,,
"['Yan, Lei', 'Li, Wei', 'Chen, Xueyang', 'Zhang, Yunlu', 'Newkirk, Joe', 'Liou, Frank', 'Dietrich, David']",2021-10-27T21:31:01Z,2021-10-27T21:31:01Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89621,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['cooling rate', 'crack formation', 'direct laser deposition', 'Ti-48Al-2Cr-2Nb']",Simulation of Cooling Rate Effects on Ti-48Al-2Cr-2Nb Crack Formation in Direct Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ad7e2dd-485d-4dee-a28c-7b6ed1fc1152/download,University of Texas at Austin,"Transient temperature history is vital in direct laser deposition (DLD) because it reveals the
cooling rate at specific temperatures, which directly relates to phase transformation and types of
microstructure formed in deposit. FEA simulation was employed to study the transient
temperature history and cooling rate at different experimental setups in Ti-48Al-2Cr-2Nb DLD
process. In this paper, an innovative model was described, which combines a moving Gaussian
distribution heat source and element birth and death technology in ANSYS, help to analysis
cooling rate control method and guide crack-free deposits build process.",,,,,,
"['Zhao, Xushan', 'Wang, Yuanxun', 'Wang, Guilan', 'Zhang, Haiou']",2021-11-18T17:35:16Z,2021-11-18T17:35:16Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90440', 'http://dx.doi.org/10.26153/tsw/17361']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['welding with rotation compression', 'WAAM', 'deformation control', 'residual stress']",Simulation of Hybrid WAAM and Rotation Compression Forming Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4828c80a-3715-428e-ac0d-83d6d0e2f658/download,University of Texas at Austin,"Wire arc additive manufacturing (WAAM) has been studied and widely applied due to its high
forming efficiency and low production cost. In the process of WAAM, there are problems of
cracking, deformation, large residual stress, insufficient properties, and instability caused by
repeated rapid heating and chilling. Welding with rotation compression can control the performance
and shape synchronously in the semi-solidified state of the weld pool. In this study, a new solution
of hybrid WAAM and rotation compression is presented using follow-up rotating device to form
the weld bead layer by layer. Base on the finite element analysis result of the hybrid process, the
force energy curve of the rotation forming metal flowing process is obtained by arranging history
monitory points and paths on the bead, and the relationship between the shape and forming load is
revealed. The simulation model was verified by forming tests on middle carbon steel.",,,,,,
"['Flach, Lawrance', 'Jacobs, Michelle A.', 'Klosterman, Donald A.', 'Chartoff, Richard P']",2019-02-25T17:27:10Z,2019-02-25T17:27:10Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73475', 'http://dx.doi.org/10.26153/tsw/625']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'lamination']",Simulation of Laminated Object Manufacturing (LOM) with Variation of Process Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/da50e362-709e-420c-b29d-d19a913ad486/download,,"A previously developed and verified thermal model for Laminated Object Manufacturing
(LOM) was used to investigate the effects of various processing parameters on the temperature
profile in a LOM part during the build cycle. The mathematical model, based on 3-dimensional
transient heat conduction in a rectangular geometry LOM part, allows calculation ofthe transient
temperature distribution within the part during the application of a new layer as well as during
other periods ofthe LOM build cycle. The parameters roller temperature, roller speed, chamber
air temperature, base plate temperature, and laser cutting time were independently varied, and the
LOM process response simulated. The results were analyzed in order to gain insight into
potential strategies for intelligent process control.",,,,,,
"['Wang, Z.', 'Smith, D.E.']",2021-11-18T17:33:44Z,2021-11-18T17:33:44Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90439', 'http://dx.doi.org/10.26153/tsw/17360']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['melt flow', 'fiber orientation', 'numerical simulation', 'Galerkin Finite Element Method', 'polymer composites', 'polymer deposition additive manufacturing']",Simulation of Mutually Dependent Polymer Flow and Fiber Filled in Polymer Composite Deposition Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cdb68d7f-ab31-4c3b-b0fb-4581c5bd84b5/download,University of Texas at Austin,"Short fiber-filled polymers experience increasing applications in melt extrusion additive
manufacturing. As the filled polymer is melted and extruded, the fiber-filled polymer suspension
exhibits mutually dependent effects, such that flow kinematics influence fiber orientation while
the fiber alignment affects the formation of melt flow. This paper presents a fully-coupled
numerical scheme to characterize the mutually dependent effects between melt flow and fiber
orientation in a non-Newtonian axisymmetric extrusion flow including a free surface using the
Galerkin Finite Element Method. The power law fluid model is employed to characterize the shear
thinning rheological behaviors of polymer melts. This approach is used to solve the fully-coupled
flow velocity and the fiber orientation fields for the nozzle extrusion flow in a large-scale polymer
deposition additive manufacturing process. Computed results obtained from both the weakly-coupled and fully-coupled schemes exhibit notable differences in the flow velocity, fiber
orientation tensor fields, die swell of free extrudate, and predicted elastic constants.",,,,,,
"['Heller, B.P.', 'Smith, D.E.', 'Jack, D.A.']",2021-11-03T20:54:46Z,2021-11-03T20:54:46Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89931,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['polymer melt flow', 'melt flow', 'fiber orientation', 'planar deposition', 'finite element analysis', 'fused filament fabrication']",Simulation of Planar Deposition Polymer Melt Flow and Fiber Orientation in Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1fb0aa5c-a1a2-4b31-a0a0-901318a465ee/download,University of Texas at Austin,"Mechanical and thermal properties of a 3D printed part are improved by adding discrete
carbon fibers to the Fused Filament Fabrication (FFF) polymer feedstock. The properties of the
fiber-filled composite are significantly influenced by the orientation of the carbon fibers within
the extruded bead where fiber orientation in the bead is affected by the nozzle internal flow
geometry, extrudate swell, and the deposition flow during the FFF process. In this work, a 2D
Stokes flow finite element analysis is performed to evaluate FFF extrusion for a large-scale
deposition extruder where special attention is given to the deposition of polymer melt on the
moving platform below the nozzle. The shape of the extruded polymer is computed using a free
surface normal velocity minimization technique. Once the velocity field and flow boundary is
computed for the bead deposition process, fiber orientation and the resulting mechanical
properties of the solidified composite are computed within the printed bead.",,,,,,
"Brown, Stuart",2018-05-03T18:16:41Z,2018-05-03T18:16:41Z,1993,Mechanical Engineering,doi:10.15781/T2348H04J,http://hdl.handle.net/2152/65052,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Materials Science and Engineering', 'SFF', 'SFF geometry', '3D Printing']",Simulation of Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e30cb355-63c1-47e0-84bd-9dd2c71ab0cd/download,,"Solid freeform fabrication involves highly coupled, nonlinear, thermomechanical processes. This
investigation simulates the formation of a simple SFF geometry, a right, rectangular prism with
aspect ratios of 1: 1:2. We include the effects of material variation, deposition path, and initial conditions
to predict resulting distortion.",,,,,,
"['Lee, Y.S.', 'Kirka, M.M.', 'Raghavan, N.', 'Dehoff, R.R.']",2021-11-03T20:29:47Z,2021-11-03T20:29:47Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89924,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['spot melting', 'scan strategy', 'solidification', 'columnar to equixaed transition', 'metal additive manufacturing']",Simulation of Spot Melting Scan Strategy to Predict Columnar to Equiaxed Transition in Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/14b633c5-5b49-4d2e-a7b2-259422adae6a/download,University of Texas at Austin,"Recently, additive manufacturing (AM) processes are transforming from rapid
prototyping technology to mass industrial production due to increase in the fidelity of the AM
machines. This trend triggers the process optimization for various applications. In prior
literature, high-fidelity numerical models have been presented to understand the rapid
solidification conditions occurring during the process which includes heat transfer, fluid flow
and beam interaction with the raw material. However, most of these models are simulating few
melt passes and it is computationally expensive to simulate an entire layer of the component
being fabricated. In this study, we use a low-fidelity model to simulate an entire layer. We also
introduce a new melt strategy to control the solidification microstructure (i.e. columnar to
equiaxed transition). The response of the solidification morphology to process parameters (ex.
point offset, power, spot time) are investigated in terms of thermal gradient G and solidification
rate R. The model is validated with the experimental microstructure data.",,,,,,
"['Temur, R.', 'Coole, T.', 'Bocking, C.']",2019-10-18T16:35:13Z,2019-10-18T16:35:13Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76254', 'http://dx.doi.org/10.26153/tsw/3343']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Electrochemical,Simulation of the Electrochemical Machining Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d94cde53-8b9d-4715-99db-6aeea1d0abed/download,,"Electrochemical machining (ECM) or erosion, is a process for shaping materials by means of the
anodic dissolution of a work-piece using suitably shaped cathodes? However, the predictability
of the process is poor due to current density variations over the electrode contour leading to poor
dimensional tolerances.
This paper describes how the process can be entirely simulated by computer. A model of the
electric field during erosion is constructed based on the Laplace equations for the field. From the
distribution of the electric field, it is possible to continuously calculate the current density at each
point on the work-piece for the whole machining process. In this way, it is possible to predict the
final work-piece contour by running the simulation program instead of the real process.
Simulations for cylindrical, conical and spherical electrodes were carried out and compared to
actual eroded parts.",,,,,,
"['Weinhold, Benjamin', 'Heck, Blake', 'Albright, Ashton', 'Wang, Keran', 'Grote, Jon-Michael', 'Adeniji, Emmanuel', 'Masoomi, Mohammad', 'Thompson, Scott']",2021-12-01T21:44:03Z,2021-12-01T21:44:03Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90623', 'http://dx.doi.org/10.26153/tsw/17542']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['distortion', 'part-to-substrate location', 'build orientation', 'part quality', 'laser powder bed fusion']",Simulation of the Laser-Powder Bed Fusion Process for Determining the Effects of Part-to-Substrate Location and Orientation on Distortion in a Connecting Rod,Conference paper,https://repositories.lib.utexas.edu//bitstreams/628518cb-2d61-46d6-8033-4fe55077df19/download,University of Texas at Austin,"The use of process simulation for designing parts and ensuring their effective additive
manufacture can result in reduced product development times which would otherwise require
costly trial-and-error manufacturing and testing experiments. The goal of this project was to
determine the effects of part-to-substrate location and part build orientation on final part quality
as measured via distortion. A connecting rod from an engine was selected for re-design for mass
reduction and additive manufacturing via laser powder bed fusion (L-PBF). The rod was
modeled and optimized using the topology optimization features of ANSYS® Workbench. A
mass reduction of ~44% was achieved and unique design features were revealed. After topology
optimization, the L-PBF process was simulated using the ANSYS Workbench Additive Wizard
while having the optimized rod in three separate orientations at two different substrate locations.
In all cases investigated, build orientation proved to have a more significant impact on distortion
than substrate location. The effect of over supporting the part for distortion control can be
investigated further to circumvent location/orientation dependencies.",,,,,,
"['Seefried, M.', 'Zaeh, M.F.', 'Meindl, M.']",2020-02-13T21:04:52Z,2020-02-13T21:04:52Z,8/31/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79980', 'http://dx.doi.org/10.26153/tsw/7005']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Indirect Metal Laser Sintering,Simulation of the Process Step Polymer Removal in Indirect Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/309d90f1-2abe-4387-9ba4-33a8c096d97a/download,,"With the Indirect Metal Laser Sintering and by means of a heat treatment in an oven process
metal components can be produced. In the first step the polymer is transformed from the solid
state into the gas phase. This takes place all over the component at different velocities depending
on the local temperatures and temperature gradients. The creation of the gas phase develops a
pressure inside of the component because the diffusion of the polymer within the part has a finite
velocity. The pressure may contribute to a damage of the component. This essay deals with the
procedure to simulate the gas pressure on the basis of the implementation of kinetic models in the
Finite-Element-Analysis.",,,,,,
"['Steinberger, J.', 'Shen, J.', 'Manetsberger, K.', 'Muellers, J.']",2019-09-23T16:40:36Z,2019-09-23T16:40:36Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75962', 'http://dx.doi.org/10.26153/tsw/3061']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Optimization,The Simulation of the SLS Process as the Basis of a Process Optimization 377,Conference paper,https://repositories.lib.utexas.edu//bitstreams/60f11499-1c84-47cb-8cb5-8b7195896451/download,,"In this work, a new model of the SLS process is introduced, offering the chance of analytically optimizing Selective Laser Sintering. The laser energy input is calculated by considering multiple scattering in the powder bed. The heat transfer is described by a new model which considers the heat flow through the growing sintering neck, and the sintering dynamics are determined by a new viscoelastic sintering model. All theoretical models are verified through experiments at near SLS conditions and are implemented in an enhanced FEM simulation of the process. Through this simulation, the major problems of the Selective Laser Sintering are illustrated and approaches for optimization of the SLS process are shown.",,,,,,
"['Delfs, Patrick', 'Herale, Ashrith Ananthraj', 'Li, Zhiyuan', 'Schmid, Hans-Joachim']",2021-10-18T22:32:25Z,2021-10-18T22:32:25Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89273,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'surface roughness', 'surface topography']",Simulation of the Surface Topography on Laser Sintered Polymer Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fccddedd-470c-48fc-976e-6af6a81cbb71/download,University of Texas at Austin,"One barrier of laser sintering (LS) to become the main process for Direct Manufacturing (DM)
is the surface quality of LS parts. Hence, the property which has to be improved is the rough
surfaces of LS parts due to the layered structure. Another additional effect is the incomplete melting
of powder particles on the surface due to the high process temperature. In this paper we demonstrate
our approach of a theoretical model for the topography of LS part surfaces.
We investigated the surface roughness as a function of surface orientation. Considering that the
model involves further variables as layer thickness, particle density and particle size distribution to
describe the topography precisely. Experimental results were used to optimize and check the results
of the model.",,,,,,
"['Zhang, Kai', 'Liu, Tingting', 'Liao, Wenhe', 'Zhang, Changdong', 'Zheng, Yi', 'Shao, Huang']",2021-11-15T20:39:52Z,2021-11-15T20:39:52Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90263', 'http://dx.doi.org/10.26153/tsw/17184']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['thermal behavior', 'molten pool', 'solidification', 'selective laser melting', 'alumina']",Simulation of the Thermal Behavior and Analysis of Solidification Process During Selective Laser Melting of Alumina,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2f44e69e-f889-43b4-8c60-d4b7fad92c73/download,University of Texas at Austin,"Selective laser melting (SLM) has rapidly developed in the past decade. High
precision-complex ceramics parts can be directly fabricated using this technology. To study
the thermal behavior of molten pools in the selective laser melting of alumina （Al2O3）, we
established a three-dimensional model based on ANSYS. Then, combined with simulation
results, the physical phenomena during the rapid solidification process were discussed. The
simulation results showed that the laser power and scanning speed exerts a marked influence
on the maximum temperature, liquid lifetime, dimensions, and temperature gradient of the
molten pool. Owing to the different temperature gradients in the molten pool, the thermal
capillary force on the free surface varies. As a result, a slight difference exists between the
stripy solidification structures. Different orientations of columnar crystals can be obtained.
The underlying mechanism controls the direction of the temperature gradient with suitable
processing routes, such as decreasing the scanning speed.",,,,,,
"['Gartner, P.', 'Krischke, N.', 'Benfer, M.', 'Bender, M.', 'Lanza, G.', 'Fleischer, J.', 'Dost, G.']",2023-04-05T13:58:09Z,2023-04-05T13:58:09Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117777', 'http://dx.doi.org/10.26153/tsw/44656']",eng,2022 International Solid Freeform Fabrication Symposium,Open,AM parts,Single Part Tracking Enabled by Fluorescent Polysecure Tracing Particles in Am Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b1e6dbf5-1de1-41f8-9fff-0615b2084400/download,,"Traceability is widely recognized as a core enabler of many industry 4.0 technologies. The 
necessary identification of products is often realized through label-based systems, but tracing 
products with particular geometric constraints that prohibit the use of such systems remains an 
issue. A promising alternative of label based identification is the pattern based identification. This 
contribution portrays a novel method to utilize fluorescent particles integrated in polymer-based 
products and optical pattern recognition to facilitate the identification of products with specific 
geometric constraints. The particles are integrated into the polymer and the unique random 
distribution of fluorescent particles triggered by an LED flash is used to recognize individual 
products. To demonstrate the approach, polymer-based gear wheels were printed using ARBURG 
plastic freeforming and an automatic identification system was designed. The presented approach 
could be a reliable alternative to other surface-structure-based approaches for product identification 
and enable comprehensive tracing of components throughout value-chains.",,,,,,
"['Borish, Michael', 'Roschli, Alex', 'Wade, Charles', 'Post, Brian', 'White, Liam', 'Adkins, Cameron']",2024-03-26T20:16:54Z,2024-03-26T20:16:54Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124391', 'https://doi.org/10.26153/tsw/50999']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['slicing', 'manufacturing', 'spiralization', 'continuous fiber deposition', 'single path', 'graph theory', 'topological hierarchy']",Single Path Generation for Closed Contours via Graph Theory and Topological Hierarchy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/532730f7-7bb8-4098-8f07-18b7bef1e79a/download,University of Texas at Austin,"Slicing converts a 3D object into a set of 2D polygons that are filled with multiple path types. These
paths involve travels where the extruder of the machine must stop building, lift, travel to the next path, lower,
and resume construction. Travels are considered wasted time as construction of the object is not occurring.
Further, the start/stop point, called a seam, causes both reduced aesthetic and weaker material properties. To
address these issues, an algorithmic approach was developed to compute a continuous single path from closed
contours. The algorithm utilizes graph theory and a topological hierarchy to produce a single path for an
individual layer. This approach can be combined with spiralization techniques to compute a single path for
entire objects. The resulting objects can be constructed quicker and have improved material properties as
verified via tensile testing.",,,,,,
"['Gong, Haijun', 'Teng, Chong', 'Zeng, Kai', 'Pal, Deepankar', 'Stucker, Brent', 'Dilip, J.J.S.', 'Beuth, Jack', 'Lewandowski, J.']",2021-10-28T21:05:11Z,2021-10-28T21:05:11Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89700,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['single track', 'support structure', 'powder bed', 'Ti-6Al-4V', 'selective laser melting']",Single Track of Selective Laser Melting Ti-6Al-4V Powder on Support Structure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8c3eb163-6248-43b7-ae34-097f3eff0983/download,University of Texas at Austin,"Melt pool shows inconsistency due to the varied heat conditions in selective laser melting (SLM)
process, even if identical process parameters are used. The characterization of the actual melt pool
shape is highly desired in order to eventually control the quality and property of additive
manufacturing products. It has been well understood that base plate provides high thermal
conduction while powder bed is low thermal condition for fusion energy to be dissipated. Based
on former study of melt pool characterization on a base plate, this study creates single tracks on
the support structure, which is considered the similar heat condition of the Ti-6Al-4V powder bed.
Various patterns of the support structure are fabricated for single track deposition, in order to
investigate the effect of the support structure on melt pool consistency and continuity. Different
laser melting parameters are used in the experiments to understand their effects on the melt pool
morphology.",,,,,,
"['Ramos, Jorge A.', 'Murphy, Jeremy', 'Lappo, Karmen', 'Wood, Kristin', 'Bourell, David L.', 'Beaman, Joseph J.']",2019-10-23T14:40:08Z,2019-10-23T14:40:08Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76749', 'http://dx.doi.org/10.26153/tsw/3838']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Superalloy,Single-Layer Deposits of Nickel Base Superalloy by Means of Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/04a1c55c-eeaf-4df0-a564-50099e7d0586/download,,"Single layer deposits consisting of Mar-M 247 powder were consolidated on
Alloy 718 polycrystalline flat sheets by means of the Selective Laser Melting (SLM)
technique. The deposition process consisted in selectively fusing a powder bed precompacted using of an insulating non-wettable mask trough. The mask-powder-substrate
arrangement was pre-heated inside a processing chamber under high vacuum. An inertreducing atmosphere was applied, and a focused Nd:YAG laser beam was then raster
scanned at high speed along the contour of the trough, providing energy to induce a
melting front to propagate along the powder as well as over the surface of the plate. As
the laser beam moved forward a solidification front was left behind with a metallurgical
bond between the substrate and the deposited layer. Optical microscopy revealed that
epitaxial growth occurred in the [001] direction from the melted substrate to about half
the height of the deposits. Above that height, the [001] dendritic front bowed towards the
[100] direction. A dendritic-equiaxed transition appeared near the free surface of the
deposit. These results indicate that the SLM technique could have potential application
for growing single crystal structures as well as in repairing damaged or worn turbine
blades.","Funding for this project was provided by Rolls-Royce North America and the
University of Texas at Austin.",,,,,
"['Nelson, Christian', 'Barlow, J.W.']",2018-04-12T17:20:57Z,2018-04-12T17:20:57Z,1990,Mechanical Engineering,doi:10.15781/T2GM8256M,http://hdl.handle.net/2152/64269,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Department of Chemical Engineering', 'Selective laser sintering', 'SLS machine']",Sintering Rates in the Selective Laser Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/345d3ebb-fc9b-4c4a-8814-9043bf8b58f4/download,,"This paper presents. a procedure to determine rates of sintering as a function of
temperature using an isothermaloven. The rate of height change of a powder sample in the
oven at temperatures near the Tg or Tm is measured. From this information an activation
energy is calculated. This activation energy is similar to activation energies calculated from
viscosity versus ternp.erature curves for polymer melts. This similarity suggests that
viscous sint~ring models such. as those by Frenkel and Scherer are appropriate. A
comparison between sintering rates of polymer coated alumina powder and mixed powders
of the polymer with alumina, suggest that better sintered products may result from the
coated powders than from simple mixtures.",,,,,,
"['Khoshnevis, Behrokh', 'Asiabanpour, Bahram', 'Mojdeh, Mehdi', 'Koraishy, Babar', 'Palmer, Kurt', 'Deng, Zongliang']",2019-10-24T18:17:50Z,2019-10-24T18:17:50Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77416', 'http://dx.doi.org/10.26153/tsw/4505']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Powder Sintering,SIS-A New SFF Method Based on Powder Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc60b55b-d7e2-4a38-9493-866d022f4f96/download,,"Selective Inhibition of Sintering is a layered fabrication process which is capable of rapidly
producing accurate functional parts out of polymers and metals using a relatively inexpensive
machine. This article presents a brief overview of the research and development aimed at
establishing the feasibility and the potential of the process.","This material is based upon work supported by the National Science Foundation under SGER
Grant No. 0088135, and Long Range Scientific and Technology Program of Office of Naval
Research.",,,,,
"['Wu, Yan', 'Yang, Li']",2021-11-09T20:33:01Z,2021-11-09T20:33:01Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90159', 'http://dx.doi.org/10.26153/tsw/17080']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['fracture behavior', 'cellular structures', 'size', 'topology effects', 'bending', 'stretching']",Size and Topology Effects on Fracture Behavior of Cellular Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3addc476-8837-45fe-8b24-6d92f7261ce5/download,University of Texas at Austin,"Cellular structures can deform by either the bending, stretching or both of the cell walls or
cell struts. In this study, the fracture characteristics of multiple typical cellular structures that
represent both the bending-dominated and stretching-dominated structures were investigated.
An analytical model based on the matrix displacement method was established for the analysis
of the fracture progression of the cellular structures, which was consequently employed for the
fracture analysis of the cellular structures under various geometry design conditions including
cell topology, cell size and number of unit cells. From the results, it was shown that the fracture
propagation patterns and stress characteristics of the two cellular designs (diamond and
triangular) exhibit different dependencies on their geometry designs and cellular patterns. While
the stretch-dominated triangular structure exhibit higher fracture strength compared to the
bending-dominated diamond structure, it also exhibits more rapid fracture propagation and
more significant size effect.",,,,,,
"['Eiamsa-ard, Kunnayut', 'Zhang, Jun', 'Liou, F.W.']",2019-09-26T17:27:00Z,2019-09-26T17:27:00Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76026', 'http://dx.doi.org/10.26153/tsw/3125']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Manufacturing,Skeleton-based Geometric Reasoning for Adaptive Slicing in a Five-axis Laser Aided Manufacturing Process System,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e638211b-26b4-4257-92c8-e7adc08f7374/download,,"Multi-axis Laser Aided Manufacturing Process (LAMP) is an additive manufacturing process similar to laser cladding. This process can produce full functional parts [1]. Traditional Layered Manufacturing processes produce parts with limited surface quality; and also the build time is often long due to the deposition of sacrificial support structure. The multiple degrees of freedom endow the LAMP system a capability to build parts without support structure. An algorithm for adaptive slicing based on skeleton is presented in this paper. The skeleton is useful for many applications such as feature recognition, robot path planning, shape analysis, and etc [2]. The near optimal build direction can be generated using information provided by the part skeleton, which is a 2D (or less) “surfaces” embedded 3D space containing the general form of the object.",,,,,,
"['Chesser, Phillip', 'Post, Brian', 'Lind, Randy', 'Roschli, Alex', 'Atkins, Celeste', 'Boulger, Alex', 'Mhatre, Paritosh', 'Lloyd, Pete']",2021-11-18T18:32:51Z,2021-11-18T18:32:51Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90459', 'http://dx.doi.org/10.26153/tsw/17380']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['SkyBAAM', 'large-scale fieldable deposition system', 'concrete deposition system', 'Oak Ridge National Laboratory']",SkyBAAM Large-Scale Fieldable Deposition Platform System Architecture,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83844e5d-8f3a-40ed-9567-ec1f7d89aedb/download,University of Texas at Austin,"Oak Ridge National Laboratory (ORNL) is currently developing a concrete deposition
system for infrastructure-scale printed objects. This system, called SkyBAAM, uses a cable driven
motion platform to manipulate the print head. This work focuses on the general aspects of the
system architecture, including arrangement of the cable driven platform, general high-level control
methodology, and system accuracy, along with concrete deposition methods. Results and
demonstration prints will be shown.",,,,,,
"['Pang, Thomas', 'Figueroa, Israel', 'Fong, John', 'Melisaris, Anastasios', 'Wang, Renyi', 'Hanna, Stephen', 'Nguyen, Hop', 'Guertin, Michelle', 'Phan, Cathy']",2018-12-05T17:27:29Z,2018-12-05T17:27:29Z,1997,Mechanical Engineering,doi:10.15781/T2P844G4D,http://hdl.handle.net/2152/71401,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SLA technology']","SL 5410: High Humidity, Water, and Heat Resistant Resin for Stereolithography",Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6cd7884-df3e-4c94-af19-451be3f2eeeb/download,,"A new Stereolithography (SL) resin, CibaTool® SL 5410, which imparts good humidity
and heat resistance, was released in July, 1997. This epoxy based resin for SLA-500 was
developed mainly to eliminate the relatively weak resistance to high humidity and high heat that
the first generation ofresins suffered from. Namely, with this new resin, strength ofQuickCast
part and solid parts can now be maintained under high relative humidity. Even when immersed
into water, part strength of SL 5410 is essentially preserved. Thermomechanical properties have
also improved significantly relative to those of SL 5180. Heat deflection temperature and Tg
values increased by +15°C to +40°C, to as high as 88°C and 105°C, respectively, for SL 5410,
when parts were additionally thermally postcured. Improvements in mechanical properties are
also included in this paper. These property enhancements were achieved while further improving
part accuracy, vertical surface finish, and productivity. Productivity may increase by as much as
2.5-fold over SL 5180. Also, SL 5410 requires no predip delay, hence cutting the overhead time.
These newly achieved resin characteristics for SL 5410 are expected to improve the ease-of-use
in today's applications, and open new fields of applications in the near future.",,,,,,
"['McPherson, Jace', 'Bliss, Adam', 'Smith, Flora', 'Hariss, Edmund', 'Zhou, Wenchao']",2021-11-02T20:24:01Z,2021-11-02T20:24:01Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89887,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['slicer', 'mobile printer', 'cooperative 3D printing', 'fused deposition modeling']",A Slicer and Simulator for Cooperative 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/12030264-9fd0-4f80-9c54-d293a7b9d41d/download,University of Texas at Austin,"Cooperative 3D printing is an emerging technology that aims to increase the 3D printing
speed and to overcome the size limit of the printable object by having multiple mobile 3D
printers (or printhead-carrying mobile robots) work together on a single print job on a factory
floor. It differs from traditional layer-by-layer 3D printing due to the requirement for multiple
mobile printers working simultaneously without interfering with each other. Therefore, a new
approach for slicing the CAD model and generating commands for the mobile printers is needed,
which has not been discussed in the literature before. We propose a chunk-by-chunk based slicer
that divides an object into chunks so that different mobile printers can print different chunks
simultaneously without interfering with each other. In this paper, we developed a slicer for
cooperative 3D printing with two mobile fused deposition modeling (FDM) printers. In order to
validate our slicer and visualize the cooperative 3D printing process, we have also developed a
simulator environment, which can be a valuable tool in optimizing cooperative 3D printing
strategy. Results show that the developed slicer and simulator are working effectively.",,,,,,
"['Sundaram, R.', 'Choi, J.']",2019-10-18T16:02:13Z,2019-10-18T16:02:13Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76245', 'http://dx.doi.org/10.26153/tsw/3334']",eng,2001 International Solid Freeform Fabrication Symposium,Open,5-Axis,A Slicing Procedure for 5-Axis layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/49e382be-21a3-4302-8ed0-e199448232cf/download,,"The 5-axis layered manufacturing technology facilitates fabrication of a part with
overhanging features without the use of supports, thereby making a direct-to-use part from the
layered manufacturing technology a reality. In this paper we describe a direct slicing procedure
for a CAD model, a crucial process planning task for the 5-axis layered manufacturing. The
neutral exchange format IGES is used as the slice format. The G and M codes for a CNC 5-axis
laser deposition machine are generated from the slice format and the deposition process is
simulated. Implemented examples are included to explain the slicing procedure. Exciting
possibilities for the future work on the slicing procedure are discussed.",,,,,,
"['Haeseong, J. Jee', 'Lee, Byong-Yeol']",2019-03-12T16:15:30Z,2019-03-12T16:15:30Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73595', 'http://dx.doi.org/10.26153/tsw/737']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD']",Slicing STEP-based CAD Models for CAD/RP Interface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a0586a06-7c8b-48f7-a258-782369df17b9/download,,"SFF technologies have an ability of creating a physical part directly .•. from its computer
model by. adding material on a layer by layer basis. One of the problems lies in their
current file fonnat for CAD data exchange. Current method using the de facto industry
standard STL have at times resulted in problems such< as accuracy, redundancy, and
integrity in its representing CAD models. In this paper we propose a method of slicing
and editing STEP...based. RP models for the new data transfer paradigm between CAD
systems and RPsystems using STEP",,,,,,
"['Ainsley, C.', 'Hon, K.K.B.']",2018-11-09T16:40:53Z,2018-11-09T16:40:53Z,1996,Mechanical Engineering,doi:10.15781/T2JH3DN57,http://hdl.handle.net/2152/69934,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['free form fabrication', 'ceramic industry', 'casting']",Slip Casting as a Rapid Tooling Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1be120a-cb2a-43b8-b8c1-3c3589da54ee/download,,"The paper discusses the slip casting ofstainless steel as a method offorming injection
moulding tooling. Main steps involved in the precision slip casting ofstainless steel
and the effects ofmajor parameters such as casting rate have on accuracy are fully
discussed. The slip casting process has numerous technical advantages over
conventional and rapid tooling processes especially there is strong potential for
producing mass production tooling.",,,,,,
"['Hagedorn, Y.-C.', 'Balachandran, N.', 'Meiners, W.', 'Wissenbach, K.', 'Poprawe, R.']",2021-10-05T14:19:35Z,2021-10-05T14:19:35Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88376', 'http://dx.doi.org/10.26153/tsw/15315']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Selective Laser Melting', 'ceramics', 'dental restorations']",SLM of Net-Shaped High Strength Ceramics: New Opportunities for Producing Dental Restorations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0ddef393-a609-4565-971d-34905b818c06/download,University of Texas at Austin,"Oxide ceramics yield excellent mechanical properties along with outstanding thermal and
wear resistance. However, little work on additive Manufacturing (AM) of high-strength ceramics
has been stated. In the present paper the current state of development in Selective Laser Melting
(SLM) of pure ceramic specimens is reviewed. During the present approach the eutectic mixture
of pure alumina (Ah0 3) and zirconia (Zr02) powder is completely molten while crack formation
is prevented by a high-temperature C02-Iaser preheating. This approach yields net-shaped, fully
dense specimens reaching flexural strengths of above 500 MPa without post-processing. One
potential application for this technology are fully-ceramic dental restorations frameworks, as the
demanded maximum loads of above I 000 N are met. Alternative preheating strategies are
presented to allow for manufacturing larger volumetric parts.",,,,,,
"['Haberer, Marc', 'Zak, Gennady', 'Park, Chul', 'Paraschivoiu, Marius', 'Benhabib, Beno']",2019-09-23T16:29:25Z,2019-09-23T16:29:25Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75956', 'http://dx.doi.org/10.26153/tsw/3055']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Ribre-Reinforced,Slot-Coating for Rapid Manufacturing of Fibre-Reinforced Parts 333,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85e3e941-a805-46f8-a093-db010808a6c9/download,,"Mechanical properties of parts manufactured through photolithography process are
improved through the addition of short glass fibres. A lithography-based prototyping system for
the manufacture of such composite parts has been under development in our laboratory. This
paper will specifically detail a novel Liquid Layer Formation Subsystem (LLFS) for the creation
of thin layers of glass-fibres/photopolymer mixture for this system. New LLFS combines a
unique external mixing subsystem with a precisely controlled slot coater in order to deposit
layers of uniform fibre volume fraction throughout the fabrication process. Evaluation of the
mixing subsystem found it capable of delivering liquid with the expected fibre content, and
examination of the geometric quality of the individual layers formed by the LLDS shows its
ability to consistently build layers of correct height.",,,,,,
"Boivie, Klas",2019-09-23T15:16:02Z,2019-09-23T15:16:02Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75932', 'http://dx.doi.org/10.26153/tsw/3031']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Sintering,SLS Application of the Fe-Cu-C System for Liquid Phase Sintering 141,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d161fe81-14ea-4fca-be7b-7f958da09ad6/download,,"The present work suggests the possibility to exploit the phenomena of copper swelling, and the controlling effect of carbon during liquid phase sintering, to be used in SLS technology to achieve temperable tooling materials in a single furnace cycle. As a basic investigation of this possibility, four powder samples of different copper and carbon content were tried and evaluated in respect to SLS and furnace behavior. The possibility to form green bodies was verified and the different sintering behaviors were studied. It was concluded that this material system holds several interesting phenomena that, if properly managed and if sufficient fractional packing density could be reached, could open distinct possibilities to achieve high quality material for SLS tooling purposes.",,,,,,
"['Kim, J.H.', 'Creasy, T.S.']",2019-10-23T14:42:49Z,2019-10-23T14:42:49Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76750', 'http://dx.doi.org/10.26153/tsw/3839']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Nanoparticle,The SLS Characteristics of 1.8wt% Clay Nanoparticle/Nylon 6 Composite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e0fdc923-6400-460b-87d4-7857dbbcbe6e/download,,"Selective laser sintering (SLS) characteristics of clay nanoparticle/Nylon 6 composite
were studied for the applications in Rapid Prototyping and Manufacturing (RP&M). Differences
of sintering behaviors between the nanocomposite and standard SLS polymers were investigated.
Nanoparticles change the material’s properties and this requires, modification of SLS processing
parameters. An attritor ground the as-received pellets into 100µm-sized particles. The
nanocomposite's sintering behavior showed higher porosity compare with standard polymers.",,,,,,
"['Niino, Toshiki', 'Sakai, Yasuyuki', 'Huang, Hongyun', 'Naruke, Hiromichi']",2020-02-27T20:58:25Z,2020-02-27T20:58:25Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80106', 'http://dx.doi.org/10.26153/tsw/7127']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Polycaprolactone powder,SLS Fabrication of Highly Porous Model Including Fine Flow Channel Network Aiming at Regeneration of Highly Metabolic Organs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8a8f554-6364-4222-80b8-06b93ee65865/download,,"Fabrication of very porous scaffold for regeneration of highly metabolic organs is
reported. Polycaprolactone (PCL) powder was mixed with fine salt grains as filler and
SLS processed to develop a model including fine flow channel network. The fabricated
model was rinsed with water to dissolve the salt, and high porosity of 90% was
successfully obtained. Additionally, residual powder in the channels was effectively
removed by solution of the filler. Through micro-CT observation, it was confirmed that
channels of which diameter was smaller than 1mm were successfully fabricated and
repeating branching and merging. Result of culture test is also reported.",,,,,,
"['Evans, R. S.', 'Bourell, D. L.', 'Beaman, J. J.', 'Campbell, M. I.']",2020-02-20T21:11:09Z,2020-02-20T21:11:09Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80056,eng,2005 International Solid Freeform Fabrication Symposium,Open,Rapid prototyping,SLS Materials Development Method for Rapid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8762714a-6d67-4e78-860b-852853597713/download,,"As soon as SFF technology development began to make Rapid Prototyping possible the
interest in Rapid Manufacturing (RM) began to grow. The advantages in terms of
functional integration, elimination of tooling and fixtures and mass customization make a
compelling case for RM, leading some in the field to call it the next industrial revolution.
Yet without the materials properties necessary to provide the function and variety
currently available from mass production methods, the application of RM will remain
limited. Developing new materials for the SLS process, one immediate step toward a
larger portfolio of RM materials, is very challenging. The formation of high quality SLS
parts relies on appropriate powder characteristics, thermal cycles and sintering behavior.
Based on a brief examination of the key factors in SLS processing and a research project
to develop a new binder material for Silicon Carbide composites, a systematic materials
development method is proposed in this paper. The method provides guidance for
introducing new SLS materials, support for educating new SLS users and researchers and
direction for several future research projects.",,,,,,
"['Muraru, L.', 'Pallari, J.', 'Creylman, V.', 'Vander Sloten, J.', 'Peeraer, L.']",2021-10-01T00:18:32Z,2021-10-01T00:18:32Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88306', 'http://dx.doi.org/10.26153/tsw/15247']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'ankle-foot orthoses', 'customized', 'computer-aided design', 'Nylon-12', 'finite element models']",SLS Nylon 12 Characterization Through Tensile Testing and Digital Image Correlation for Finite Element Modeling of Food and Ankle-Foot Orthoses,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b704dbb-40e1-42f0-9cc4-8b18c72aeabe/download,University of Texas at Austin,"Selective Laser Sintering has been recently proposed as a feasible engineering technique
for manufacturing of customized ankle-foot orthoses (AFOs). Development of
computer-aided design (CAD) models and virtual evaluation of the orthotic devices are
important steps in the engineering design process. This paper will describe a method for
accurate characterization of SLS Nylon 12 mechanical properties to be implemented in
the finite element models (FEM) of AFOs. Elastic mechanical properties were
determined for principal and perpendicular building directions.",,,,,,
"['Choren, J.', 'Gervasi, V.', 'Herman, T.', 'Kamara, S.', 'Mitchell, J.']",2019-10-09T16:00:16Z,2019-10-09T16:00:16Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76145', 'http://dx.doi.org/10.26153/tsw/3234']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Powder,SLS Powder Life Study,Conference paper,https://repositories.lib.utexas.edu//bitstreams/777e258a-c7db-4ad7-894a-0e3217fde152/download,,"Producing acceptable models on the Selective Laser Sintering (SLS) machine involves
adjusting machine parameters relative to powder age. Typically, a fraction of the powder is used
and the remainder of the unused powder is recycled. After 5-7 recycles, this method leads to a
powder inventory with inconsistent characteristics. The goal of this study was to apply a new
recycling program to extend powder life, reduce powder inventory, and improve part quality.
This study looks at various material properties of processed powder over its lifetime, including:
surface quality, toughness, impact strength, elastic modulus, tensile strength, and shrinkage. A
new approach to powder recycling and machine parameter adjustment will be recommended.",,,,,,
"['Jepson, L.', 'Beaman, J. J.', 'Bourell, D. L.', 'Wood, K. L.']",2018-11-28T19:35:53Z,2018-11-28T19:35:53Z,1997,Mechanical Engineering,doi:10.15781/T2TQ5S07J,http://hdl.handle.net/2152/70327,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SLS process', 'powder delivery', 'Selective Laser Sintering']",SLS Processing of Functionally Gradient Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/75923433-2750-4aa4-aea0-22014dc6587a/download,,"A developing SLS process, known as Multiple Material Selective Laser Sintering,
will allow the material composition of a component to be varied in a controlled
manner. This process could allow the fabrication of functionally gradient materials
(FGMs) in which a blended interface exists. Two potential applications of FGMs are
the reduction of thermal stresses in metal/ceramic joints and the matching of
material properties to functional requirements. A tungsten carbide/cobalt system has
been examined in which the ceramic/metal ratio has been varied in an attempt to
control the hardness/fracture resistance _ratio. An FGM powder bed was manually
fabricated using a discrete banding technique. Results of traditional SLS processing
of this powder bed are presented.",,,,,,
"['Cheng, J.', 'Lao, S.', 'Nguyen, K.', 'Ho, W.', 'Cummings, A.', 'Koo, J.']",2020-02-20T20:58:27Z,2020-02-20T20:58:27Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80052,eng,2005 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,SLS Processing Studies of Nylon 11 Nanocomposites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c41a4e2b-0cea-4e81-9ab6-28c985413c74/download,,"Selective Laser Sintering (SLS) is widely used for rapid prototyping/manufacturing of
nylon 11 and nylon 12 parts. This processing technique has not been explored for
nylon nanocomposites. This study investigates the technicalities of processing nylon
11-clay and nylon-carbon nanofiber nanocomposites with SLS. Microstructural
analyses of the SLS powders and parts were conducted under SEM. Results suggest
that SLS processing is possible with the new nylon 11 nanocomposites. Yet the SLS
parts built have inferior properties relative to those of injection molding, suggesting
that more fine tuning for the processing is required.",,,,,,
"['Forderhase, Paul', 'McAlea, Kevin', 'Michalewicz, Mary', 'Ganninger, Mark', 'Firestone, Kent']",2018-09-26T20:52:25Z,2018-09-26T20:52:25Z,1994,Mechanical Engineering,doi:10.15781/T2WD3QM05,http://hdl.handle.net/2152/68596,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'Compression molded', 'SLS Nylon Processing']",SLSTM Prototypes From Nylon,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d3d8d786-b644-41a4-ad92-c793eec64557/download,,"Many rapid prototypmg materials and processes produce parts which have relatively low
stiffness, strength, and ductility. While such parts are useful for visualization, they have limited value
where functional features are necessary or where application testing is required. In order to satisfy these
more demanding requirements, rapid prototyping materials which offer part performance representative of
molded plastics are required.
DTM has developed and commercialized nylon-based materials (LN-4010 and LNF-5000) for the
SLS process which produce strong, durable parts without the use of constraint or support structures. In
order to produce dimensionally accurate SLS nylon parts, careful control of the thermal environment is
required during the entire process cycle. In this paper, the thermal control elements necessary to achieve
this goal are described. Background information concerning SLS nylon part performance and material
process behavior is also provided.",,,,,,
"['Cima, M.J.', 'Oilveira, M.', 'Wang, H.R.', 'Sachs, E.', 'Holman, R.']",2019-10-10T17:28:11Z,2019-10-10T17:28:11Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76177', 'http://dx.doi.org/10.26153/tsw/3266']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Ceramic,Slurry-Based 3DP and Fine Ceramic Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53cb9f52-829f-4da2-aa92-838014c95dd2/download,,"Slurry-based 3DPTM (S-3DPÔ) is a solid freeform fabrication technique developed at MIT for
production of fine ceramic components with complex geometries and fired densities in excess of
99% of theoretical density. Current research involves identification of the factors controlling
minimum feature size in S-3DPTM. The ink-jet printed binder droplet size is the primary factor
controlling the minimum feature dimension when deposited on the powder layers. For a given
droplet size, however, a balance between spreading of the binder solution on the surface of the S3DPTM powderbed and infiltration determine the feature size, while interactions between the
polymeric binder and the powder surface (polymer adsorption) control the minimum feature
cross-section. Droplet-on-demand printing of the binder solution has been introduced to improve
resolution, decreasing the minimum feature width from 300 mm to less than 150 mm.",,,,,,
"['Erhard, P.', 'Volk, W.', 'Guenther, D.']",2024-03-27T03:15:57Z,2024-03-27T03:15:57Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124460', 'https://doi.org/10.26153/tsw/51068']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['slurry-based binder jetting', '3D printing', 'foundry', 'casting cores', 'ceramics']",SLURRY-BASED BINDER JETTING OF CERAMIC CASTING CORES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8b7f36fa-3fd0-4f65-a0bd-46741a2dcf2f/download,University of Texas at Austin,"The production of complex sand cores to represent internal contours in castings is typically
achieved by powder-based binder jetting. However, a trade-off between the load-bearing capacity
during casting and the subsequent removability from the cast part leads to design limitations.
Slurry-based binder jetting allows the processing of fine powders and the economical production
of sinterable ceramic cores. Its performance, potential, and challenges are presented in the context
of the foundry process chain. As drying affects material properties and process efficiency, detailed
investigations are carried out to control the properties via drying. Average roughness depths of 1.2
µm and flexural strengths of 25 MPa were achieved using aqueous quartz slurry and appropriate
process parameters. By incorporating predetermined breaking lines into the internal geometry of
hollow casting core structures, the stress generated during the solidification of the cast metal
induces decoring. A promising process chain is outlined for producing efficient, close-contour
coolings in high-performance castings and digital code tags for part tracking in foundries.",,,,,,
"['Meyers, Sebastian', 'Feys, Quinten', 'Yang, Shoufeng', 'Vleugels, Jef', 'Kruth, Jean-Pierre']",2021-11-09T21:07:14Z,2021-11-09T21:07:14Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90168', 'http://dx.doi.org/10.26153/tsw/17089']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['alumina', 'additive manufacturing', 'laser sintering', 'powder metallurgy']",Slurry-Based Laser Sintering of Alumina Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/071f5cea-eaa8-44f1-a971-c3e2677da54b/download,University of Texas at Austin,"In this work, a slurry-based laser sintering process is investigated. Laser sintering allows
for a broad palette of materials to be used. Since the binder content is only about 16 vol% with
respect to the ceramic powder load, the debinding process is faster and less susceptible to crack
formation and part warping compared to lithography-based manufacturing. The alumina slurry,
used as a starting material for laser sintering, was optimized by adjusting the dispersant content to
reach a minimum viscosity. After debinding and furnace sintering, multi-layer alumina parts with
densities up to 97% were obtained.",,,,,,
"['Hossain, Mohammad Shojib', 'Gonzalez, Jose A.', 'Martinez Hernandez, Ricardo', 'Morton, Philip', 'Mireles, Jorge', 'Choudhuri, Ahsan', 'Lin, Yirong', 'Wicker, Ryan B.']",2021-11-08T21:25:57Z,2021-11-08T21:25:57Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90045', 'http://dx.doi.org/10.26153/tsw/16966']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['smart parts', 'powder bed fusion', 'additive manufacturing', 'fabrication process']",Small Parts Fabrication Using Powder Bed Fusion Additive Manufacturing Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/686d9665-e09f-4c49-a65c-22a8c250e3dd/download,University of Texas at Austin,"Metallic components with embedded sensors or smart parts can be a beneficial tool for
monitoring harsh environments in the energy, biomedical, automotive, and aerospace industries.
Smart parts maintain structural integrity with added functionality of sensing temperature, pressure,
and structural health. A non-intrusive placement of a sensor in metallic components was
developed using powder bed fusion additive manufacturing (AM). A paused build procedure was
used to fabricate a proof of concept, a cylindrical shaped smart part using both electron beam
melting (EBM) and selective laser melting (SLM) technologies. This paper focuses on the
fabrication process and characterization of the smart part. A functional complex shaped energy
system component, a smart injector was fabricated to demonstrate the applicability in harsh
environments. The pressure and temperature sensing capabilities were tested using compressive
cyclic loading and hot fire testing in a combustion chamber testing. A maximum sensing response
of 3V was obtained for EBM fabricated smart part while applying compressive load. An image
analysis based part positioning method was demonstrated for EBM technology that can be
employed in other AM technologies to alleviate or completely remove misalignment in a paused
build fabrication process.",,,,,,
"['Alghamdi, F.', 'Verma, D.', 'Haghshenas, M.']",2021-11-10T23:02:47Z,2021-11-10T23:02:47Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90203', 'http://dx.doi.org/10.26153/tsw/17124']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['small-scale property', 'microstructural assessment', 'depth-sensing', 'depth-sensing indentation', 'aluminum alloy', 'additive manufacturing']",Small-Scale Characterization of Additively Manufactured Aluminum Alloys Through Depth-Sensing Identification,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4def42bb-5ffb-4ba0-bae7-b71849a3fad8/download,University of Texas at Austin,"Selective laser melting (SLM) can be considered as a suitable additive manufacturing
method for printing complex-in-shape aluminum components. However, to adopt the SLM for
mass production of aluminum components for automotive and aerospace applications, one needs
to fully understand the correlations between the SLM parameters, produced microstructure, and
local mechanical properties of the printed parts. In this paper, along with microstructural
assessments (optical and scanning electron microscopy), small-scale properties of two additively
manufactured aluminum alloys, AlSi10Mg and A205.0, were examined using an instrumented
(depth-sensing) indentation testing technique. An instrumented indentation testing approach is a
semi-destructive, reliable and convenient method which enables us to study the variations and
distributions of the mechanical properties (i.e. hardness) as a function of distance from the build
plate. The variations in properties are then compared in AlSi10Mg and A205.0 alloys and are
correlated to the generated microstructures in the printed alloys.",,,,,,
"['Haghshenas, M.', 'Totuk, O.', 'Masoomi, M.', 'Thompson, S.M.', 'Shamsaei, N.']",2021-11-02T14:02:55Z,2021-11-02T14:02:55Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89806,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['Ti-6Al-4V', 'additive manufacturing', 'mechanical properties', 'nanoindentation', 'microstructure']",Small-Scale Mechanical Properties of Additively Manufactured Ti-6Al-4V,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4925d796-0a72-41c8-af60-5a67de084dd4/download,University of Texas at Austin,"This article aims at studying microstructure and nano/micro-scale mechanical responses of Ti-6Al-4V fabricated using a Laser-based Powder Bed Fusion (L-PBF) method. To this end, an
instrumented depth-sensing nanoindentation system has been used to assess hardness, Young’s
modulus, strain rate sensitivity and rate dependent plastic deformation of the alloy at different
build Orientations (in the Z-plane and X-plane) at ambient temperature. Indentation tests were
conducted at constant proportional loading rate of 15 mN/s in a depth-controlled (hind=2000 nm)
testing regime. The Microstructure characterizations were performed using optical and scanning
electron microscopy to assess the correlations to the mechanical properties achieved by the
nanoindentation testing to better establish structure-property relationships for L-PBF Ti-6Al-4V.
It is expected that the fine microstructure, developed by fast solidification during the L-PBF
process, to directly contribute to the nanoindentation measurements at different strain rates.",,,,,,
"['Liu, Renwei', 'Wang, Zhiyuan', 'Zhang, Yunlu', 'Sparks, Todd', 'Liou, Frank']",2021-10-28T14:40:42Z,2021-10-28T14:40:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89653,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'toolpath generation', 'additive manufacturing']",A Smooth Toolpath Generation Method for Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/885b1f5f-e05c-485b-9e1e-6a536dfb954b/download,University of Texas at Austin,"Laser metal deposition (LMD), also known as direct metal deposition (DMD) or laser engineered
net shaping (LENS), which uses a laser beam to form a melt pool on a metallic substrate, into
which powder or wire is fed. The conventional contour and zigzag toolpath pattern for LMD are
discontinuous at turn points or corner points. The discontinuous toolpath causes uneven
deposition, which brings height variation and porosity problems. This paper aims to develop a
smooth toolpath generation method for LMD to improve the deposition quality. A parametric
curve equation based on trigonometric functions is derived and built. It can be used for arbitrary
smooth connections or transitions in toolpath planning and provide constant feedrate for
deposition. The proposed method was applied to a patch deposition experiment and a component
repair experiment with Ti-6Al-4V powder. The experimental results show that the smooth
toolpath can noticeably improve the dimensional accuracy and surface roughness and reduce
porosity.",,,,,,
"['Carvalho, C.', 'Landers, R.', 'Mülhaupt, R.']",2020-02-17T15:31:33Z,2020-02-17T15:31:33Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80011', 'http://dx.doi.org/10.26153/tsw/7036']",eng,2004 International Solid Freeform Fabrication Symposium,Open,polymer melts,Soft and Hard Implant Fabrication Using 3D-Bioplotting TM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ac082af-da0f-4f8f-b010-8115f85d6bd0/download,,"At the Freiburger Materialforschungszentrum we have developed a new process (3DBioplotting
TM) that permits most kind of polymers and biopolymers to be used in 3D scaffold
design, including hydrogels (e.g. collagen, agar), polymer melts (e.g. PLLA, PGA, PCl) and twocomponent systems (e.g. chitosan, fibrin). Cells can be incorporated within the construction
process, making this an ideal Rapid Prototyping technique for Organ Printing. Tailor-made
biodegradable soft or hard scaffolds can so be fabricated in a short time using individual
computer-tomography data from the patient. In-vitro tests showed promising results and in-vivo
experiments are now under observation.",,,,,,
"['Elkins, Kurt', 'Nordby, Howard', 'Janak, Christopher', 'Gray IV, Robert W.', 'Helge Bohn, Jan', 'Baird, Donald G.']",2018-12-05T20:29:54Z,2018-12-05T20:29:54Z,1997,Mechanical Engineering,doi:10.15781/T2833NJ55,http://hdl.handle.net/2152/71413,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['aircrewoxygen', 'STPE']",Soft Elastomers for Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac34d988-7e22-4a30-8ce9-b1269f630e98/download,,"This paper describes an ongoing effort towards extending the capabilities of the fused deposition
modeling (FDM) process to soft thermoplastic elastomers (STPEs). Two thermoplastic
elastomers with hardness of 72 and 78 Shore A, respectively, have been processed into 0.070""
(1.78 mm) filament stock for use in the FDM 1600 rapid prototyping system. The FDM 1600
liquifier subsystem has been modified to accommodate the reduced column strength ofthe STPE
filament stock. Sample STPE parts have been fabricated with ABS material support structures.",,,,,,
"['Lee, Cheol H.', 'Gaffney, Thomas M.', 'Thomas, Charles L.']",2018-11-09T16:54:22Z,2018-11-09T16:54:22Z,1996,Mechanical Engineering,doi:10.15781/T21J97T4W,http://hdl.handle.net/2152/69938,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SCA', 'SLA', 'LOM']",Soft Tooling for Low Production Manufacturing of Large Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fbe8ddd2-a7f0-4632-8ebf-d99a80cca425/download,,"A new technique for building large prototypes from layered substrate relies on a higher
order construction algorithm to produce accurate prototypes from thick layers. The process is
capable ofproducing a 4' by 8' by 20' object in less than two days. Using this technique to
produce molds instead ofparts allows construction oflarge castings and composite structures.
Example parts include composite airfoils, a 19 foot canoe, and a custom fairing for a racing car.",,,,,,
"['Ensz, M. T.', 'Griffith, M. L.', 'Harrwell, L. D.']",2019-02-22T20:02:53Z,2019-02-22T20:02:53Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73470', 'http://dx.doi.org/10.26153/tsw/620']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['LENS', 'CAD']",Software Development for Laser Engineered Net Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c220cb6-82e6-47da-be66-47c1d0334e44/download,,"Laser Engineered Net Shaping, also known as LENSTM, is an advanced manufacturing technique used to
fabricate near-net shaped, fully dense metal components directly from computer solid models without the
use oftraditional machining processes. The LENSTM process uses a high powered laser to create a molten
pool into which powdered metal is injected and solidified. Like many SFF techniques, LENSTM parts are
made through a layer additive process. In the current system, for any given layer, the laser is held
stationary, while the part and its associated substrate is moved, allowing for the each layer's geometry to
be formed. Individual layers are generated by tracing out the desired border, followed by filling in the
remaining volume. Recent research into LENSTM has highlighted the sensitivity ofthe processes to
multiple software controllable parameters such as substrate travel velocity, border representation, and fill
patterns. This research is aimed at determining optimal border outlines and fill patterns for LENSTM and
at developing the associated software necessary for automating the creation ofthe desired motion control.",,,,,,
"Dreher, Stefan",2019-10-18T16:32:56Z,2019-10-18T16:32:56Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76253', 'http://dx.doi.org/10.26153/tsw/3342']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Configuration,Software for the Interactive Configuration of RP Based Process Chains,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f020c17e-b59f-4de2-83ef-5ceb19ebc3b5/download,,"In product development, time is one of the most critical factors. By introducing Rapid Prototyping methods, development time can be reduced dramatically. But the required characteristics of the generated prototypes become more and more complex. As a result, a great variety of Rapid Prototyping devices and services have emerged on the market. The product developer may be highly satisfied with the wide range of new potentials, tools and methods but who will give an orientation about the most suitable process chain to fulfill his demands? To solve the problem, a new software is being developed at the Fraunhofer Institute IPK in Berlin, the iViP-RPSelector. In a first step, the software tracks a record of the demands to the prototype. These values can be inserted manually, but there is an interface as well connecting the RPSelector to CAD and PDM systems to obtain the design parameters without user interaction. The RPSelector then calculates a completer RP based process chain, which may comprise a layer wise creation, some post processing, a copying process and several finishing processes.",,,,,,
"['Crawford, Richard H.', 'Beaman, J.J.', 'Das, Suman']",2018-04-12T18:06:49Z,2018-04-12T18:06:49Z,1991,Mechanical Engineering,doi:10.15781/T2KD1R309,http://hdl.handle.net/2152/64277,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Mechanical Engineering', 'Solid Freeform Fabrication', 'SFF', 'SLS']",Software Testbed for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/754a413e-1c5e-43c8-8a74-ab4538c34c9a/download,,"Computer software plays an important role in the implementation of Solid Freeform
Fabrication (SFF) technologies. This paper describes a software testbed for processing
part geometry for a particular SFF technology, selective laser sintering (SLS), that is built
around the separation of the slicing and rasterization operations to accommodate geometric
information from a variety of sources. The paper also discusses the process control
software being developed for a new high-temperat rkstation for SLS of metal
powders. This program features a high-resolution data rmat, the ability to interpolate
to achieve a desired resolution, and a menu-driven user interface with graphical feedback
and process simulation capabilities.",,,,,,
"['Stuffle, Kevin', 'Mulligan, Anthony', 'Calvert, Paul', 'Lombardi, John']",2018-05-03T16:53:19Z,2018-05-03T16:53:19Z,1993,Mechanical Engineering,doi:10.15781/T2WM14B4S,http://hdl.handle.net/2152/65038,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['CAD systems', 'photocurable polymers']",Solid Freebody Forming of Ceramics from Polymerizable Slurry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea27bc59-0ef0-482c-afd8-2bc03fb5d61e/download,,"In solid free body forming a component is described by a CAD system as a series
of slices. The slices are deposited as a sequence of layers which are.cured or solidified
by a moving head such that a three dimensional part is built up. Systems have been
developed based on photocurable polymers, solidifying polymer melts, laser fused
powder layers, polymer-bound powders and others.",,,,,,
"['Bourell, D.L.', 'Beaman, J.J.', 'Marcus, H.L.', 'Barlow, J.W.']",2018-04-10T16:01:44Z,2018-04-10T16:01:44Z,1990,Mechanical Engineering,doi:10.15781/T2W08X029,http://hdl.handle.net/2152/64233,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'SFF', 'The Center for Materials Science and Engineering', 'Mechanical Engineering Department', 'Chemical Engineering Department', 'The University of Texas at Austin']",Solid Freeform Fabrication An Advanced Manufacturing Approach,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6bafd42a-d410-451b-81d2-13aeda96733c/download,,,,"Solid freeform fabrication (SFF) is the production of freeform solid objects directly from a
computer model without part-specific tooling or human intervention. SFF has been realized in the
last ten years through the merging of several previously distinct technologies: computer science,
mechanical design, controls, high-energy beam technology and materials science and engineering.
Their combination has produced over a relatively short time..frame numerous SFF methods. The
value of SFF to the commercial sector is usually articulated in terms of reduced time to market
(prototyping), low production ""one-of-a-kind"" parts and patterns for casting. The purpose of this
introductory paper is to describe briefly some of the approaches to SFF as a background for the
articles included in this proceedings.",,"['Bourell, D.L.', 'Beaman, J.J.', 'Marcus, H.L.', 'Barlow, J.W.']",,
"Boudreaux, J.C.",2019-10-23T15:22:12Z,2019-10-23T15:22:12Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76760', 'http://dx.doi.org/10.26153/tsw/3849']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Parametric,Solid Freeform Fabrication and Parametric Engineering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/998b9b8d-3042-4ac8-a7b3-4b41b968aea1/download,,"Solid freeform fabrication (SFF) is based on a part-centric process model: create a solid model of the
part, form planar slices, and fabricate the part by producing all of the polyhedra by any of several methods. A class
of applications is emerging which will pull SFF from the part-centric model to a new paradigm in which parts are
seen as components of interactive networks. This is precisely the context for which parametric engineering has been
proposed. In this paper, a computational framework will be developed that consists of a finitary topological
representation of parts as 3-manifolds and representation of the evaluative context by means of a symbolic
environment. Parametric engineering is interpreted as a controlled evaluation of parameters within the context of
the symbolic environment.",,,,,,
"Watkins, K. G.",2019-12-05T17:08:33Z,2019-12-05T17:08:33Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/78648', 'http://dx.doi.org/10.26153/tsw/5704']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Interface,Solid Freeform Fabrication and the Interface with Direct Write,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44195a61-b63e-4750-8dc7-eb5685a5107f/download,,"An overview is given of research activity in solid freeform fabrication (SFF) in England’s
Northwest, concentrating on work in the Laser Group at University of Liverpool (including the
Lairdside Laser Engineering Centre) and at the Laser Processing Research Centre at UMIST.
This work is placed in the context of the strategy for science in the Northwest and its aims in
developing and supporting industrial capability, showing that laser based approaches, including
SFF, are regarded as key enabling technologies. The account also includes a consideration of the
interface between SFF and other “Direct Write” technologies and outlines the recent
development of Direct Write initiatives in the UK.",,,,,,
"['Wang, Wanshan', 'Wu, Wenzheng', 'Yu, Tianbiao', 'Qin, Xingjun', 'Chen, Yadong', 'Rosen, David W.']",2021-10-01T00:59:28Z,2021-10-01T00:59:28Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88312', 'http://dx.doi.org/10.26153/tsw/15253']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'mandible reconstruction', 'computer aided design']",Solid Freeform Fabrication Assisting Free Fibula Flap for the Reconstructive Surgery of Mandibular Defects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/051ba1ff-fec5-4eca-8477-aed8a4fb6abc/download,,"The usage of RP models can shorten the operation time for reconstructive surgery of mandible
defects using the free fibula flap technique and can improve the accuracy of mandible
reconstruction. This paper reports on a case study of reconstructive surgery on a patient with a
mandibular defect caused by a tumor. A customized mandible rapid prototype model was
manufactured from the patient’s CT data and was used to simulate the reconstructive surgery
procedure. A customized titanium plate was shaped using the mandible RP model as a pattern
before surgery. The usage of a mandible RP model reduced the operation time by 1.5-2.5 hours
and the shape precision of the reconstructed mandible was improved. The customized titanium
plate was consistent with the mandible anatomy.",,,,,,
"['Harrison, Shay', 'Crocker, James E.', 'Manzur, Tariq', 'Marcus, Harris L.']",2018-11-14T18:02:28Z,2018-11-14T18:02:28Z,1996,Mechanical Engineering,doi:10.15781/T26H4D94J,http://hdl.handle.net/2152/70254,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SALD', 'SFF', 'Chemical Vapor Deposition']",Solid Freeform Fabrication at The University of Connecticut,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b57b2fcb-e9c6-471d-a6d5-e2f5297fe45d/download,,"Gas phase solid freeform fabrication research at The University of Connecticut focuses
on two main procedures, Selective Area Laser Deposition (SALD) and Selective Area Laser
Deposition Vapor Infiltration (SALDVI). A SFF research laboratory is under construction at
UCONN, with two new operation systems. These systems possess temperature control, data
acquisition capabilities, in-situ video monitoring, and the ability to fabricate SALDVI parts up
to four inches wide by four inches long. The procurement of a harmonic generating Nd:YAG six
watt laser, capable of producing output at 532, 355, and 266 nanometer wavelengths, as well as a
coupled effort with the Photonics Center at the University providing laser diodes at a variety of
wavelengths, presents the opportunity to explore interactions involved in gas reactions driven by
lasers. Investigations of material systems will include ceramic carbides, nitrides, and their
composites, as well as metals.",,,,,,
"['Wang, Huijun', 'Jiang, Wenhui', 'Valant, Michael', 'Kovacevic, Radovan']",2019-11-20T16:43:57Z,2019-11-20T16:43:57Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78480', 'http://dx.doi.org/10.26153/tsw/5565']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Micro-Plasma,Solid Freeform Fabrication Based on Micro-Plasma Powder Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/295ee298-1d4a-4fda-b8ae-58ba7a4b5dd6/download,,"This paper presents a solid freeform fabrication (SFF) technique based on micro-plasma powder
deposition (MPPD). The relationship between the geometric features of the deposited layers and
the welding parameters is investigated. The arc length is controlled through the monitoring of the
arc voltage. The result of building parts with functionally graded components by the MPPD
process is shown as well. The microstructure and the properties of the deposited layers are
analyzed. The experimental results show that the MPPD process is a promising welding-based
solid freeform fabrication technology.",,,,,,
"['Kumar, Ashok V.', 'Dutta, Anirban', 'Fay, James E.']",2019-11-15T15:57:55Z,2019-11-15T15:57:55Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78417', 'http://dx.doi.org/10.26153/tsw/5504']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Electrographic,Solid Freeform Fabrication by Electrographic Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/11dff1e3-a7fa-4289-8fb6-be90580aa838/download,,"A solid freeform fabrication technique is described where powder is deposited layer by layer using electrophotographic printing. In this process, powder is picked up and deposited using a charged photoconducting surface and deposited on a build platform. The paper describes a test bed that was designed and constructed to study the application of electrophotography to solid freeform fabrication. It can precisely deposit powder in the desired shape on each layer. The electric field required to transfer the powder on to the platform (or onto previously printed layers) was studied. A polymer toner powder was used to build small components by fusing each layer of printer powder using a hot compaction plate.",Funding for this research from NSF grand number DMI-9875445 and ONR grant N00014-98-1-0694 is gratefully acknowledged.,,,,,
"['Zong, G.S.', 'Carnes, R.', 'Wheat, H.G.', 'Marcus, H.L.']",2018-04-10T18:08:43Z,2018-04-10T18:08:43Z,1990,Mechanical Engineering,doi:10.15781/T2KK94V9T,http://hdl.handle.net/2152/64243,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Laser Chemical vapor deposition', 'SFF', 'SEM', 'Raman microprobe']",Solid Freeform Fabrication by Selective Area Laser Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/30d66043-1a3b-44be-82fe-7608412c2758/download,,"Laser chemical vapor deposition is capable of selective area deposition of thin fums at high
spatial resolution, and in the present work this advantage was used to perform solid
freeform fabrication (SFF). The pyrolytic selective area laser deposition of carbon is
studied as a function of the scanning speed, the laser power, and the diameter of the focal
spot on the substrate, at different pressures of the acetylene precursor in a gas phase SFF
system. Carbon rods and rings have been made. SEM and Raman microprobe were used to
characterize the deposits.",,,,,,
"['Wang, Jiwen', 'Shaw, Leon L.', 'Xu, Anping', 'Cameron, Thomas B.']",2020-02-20T18:35:37Z,2020-02-20T18:35:37Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80037', 'http://dx.doi.org/10.26153/tsw/7059']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solid Freeform Fabrication,Solid Freeform Fabrication of Artificial Human Teeth,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8c9f2fd6-3974-418d-b8fc-015425da755e/download,,"In this paper, we describe a solid freeform fabrication procedure for human dental
restoration via porcelain slurry micro-extrusion. Based on submicron-sized dental porcelain
powder obtained via ball milling process, a porcelain slurry formulation has been developed. The
formulation developed allows the porcelain slurry to show a pseudoplastic behavior and
moderate viscosity, which permits the slurry to re-shape to form a near rectangular cross section.
A well-controlled cross-section geometry of the extrudate is important for micro-extrusion to
obtain uniform 2-D planes and for the addition of the sequential layers to form a 3-D object.
Human teeth are restored by this method directly from CAD digital models. After sintering,
shrinkage of the artificial teeth is uniform in all directions. Microstructure of the sintered teeth is
identical to that made via traditional dental restoration processes.",,,,,,
"['Shanjani, Yaser', 'Toyserkani, Ehsan', 'Pilliar, Robert']",2021-09-23T22:55:29Z,2021-09-23T22:55:29Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88048', 'http://dx.doi.org/10.26153/tsw/14989']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['solid freeform fabrication', 'dual-porous structure scaffolds', '3D-printing', 'calcium polyphosphate', 'polyvinyl alcohol']",Solid Freeform Fabrication of Calcium Polyphosphate Dual-Porous Structure Osteochondral Scaffold,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83fdeb5c-c591-4c9e-9c1e-1601901733aa/download,,"In this work the solid freeform fabrication (SFF) of dual-porous structure scaffolds using the
3D-printing method is investigated. The structure, including a cartilage substrate and a bone
scaffold with different porosities and pore sizes, provide a suitable facility for repairing the
osteochondral tissues in the implanted site. Calcium polyphosphate (CPP), with distinct particle
sizes for each portion, was utilized as the biomaterial. Polyvinyl alcohol (PVA), as a
biocompatible polymer was also used as a binder to adhere the CPP particles upon injecting of a
solvent through the 3D-printing process. The prototyped parts are finally post-processed in the
controlled furnace to obtain the required bio-mechanical properties. The biomechanical
properties of the fabricated samples are also characterized by the X-ray diffraction (XRD),
scanning electron microscopy (SEM), and density analysis.",,,,,,
"['Sindelar, R.', 'Buhler, P.', 'Niebling, F.', 'Otto, A.', 'Greil, P.']",2019-10-22T18:22:19Z,2019-10-22T18:22:19Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76335', 'http://dx.doi.org/10.26153/tsw/3424']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Ceramic,Solid Freeform Fabrication of Ceramic Parts from Filler Loaded Preceramic Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd337b1e-91c9-4050-b306-f52dce55e005/download,,"Manufacturing of ceramic parts was achieved by selective laser treatment of a
preceramic polymer (polysiloxane) loaded with ceramic filler powder (alumina). Thin layers
of polymer/filler powder mixture were sequentially cured with a CO2-laser (λ=10.6 µm)
thereby generating the geometrical shape of the part. Subsequently, the cured thermoset part
was annealed in nitrogen atmosphere at 600 to 1000 °C to convert the compact into a Si-OC/Al2O3 micro-composite material. Dimensional changes upon pyrolysis (∆l/l0 ≈ 3 %) can be
controlled by adjusting the polymer-to-filler ratio and the heat treatment conditions. The new
process is called Selective Laser Curing (SLC).","Financial support of Fonds der Chemischen Industrie and Deutsche
Forschungsgemeinschaft is gratefully acknowledged.",,,,,
"['Griffin, Curtis', 'Daufenbach, JoDee', 'McMillin, Scott']",2018-09-26T18:38:54Z,2018-09-26T18:38:54Z,1994,Mechanical Engineering,doi:10.15781/T2ZC7SD22,http://hdl.handle.net/2152/68582,,1994 International Solid Freeform Fabrication Symposium,Open,"['Laminated Object Manufacturing', 'Lone Peak Engineering', 'CAD']",Solid Freeform Fabrication of Functional Ceramic Components Using a Laminated Object Manufacturing Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a635fc6-ef1c-4157-b9a5-909db91d4127/download,,"Lone Peak Engineering (LPE) has demonstrated the feasibility ofusing solid freeform
fabrication to prepare advanced structural ceramics using a laminated object manufacturing (LOM)
technique. High purity, high density alumina ceramic components were successfully made using the LOM
process. The properties oft he laminated object manufactured (LOMed) components were very
similar to the physical and mechanical properties of alumina ceramics that were prepared by a
conventional pressing process. The LOMed ceramics were also very similar in properties to
commercially available alumina ceramics.",,,,,English,
"['Rodrigues, S. J.', 'Chartoff, R. P.', 'Klosterman, D. A.', 'Agarwala, M.', 'Hecht, N.']",2019-06-13T14:01:24Z,2019-06-13T14:01:24Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/74940', 'http://dx.doi.org/10.26153/tsw/2052']",eng,2000 International Solid Freeform Fabrication Symposium,Open,"['silicon nitride', 'LOM', 'ceramics']",Solid Freeform Fabrication of Functional Silicon Nitride Ceramics by Laminated Object Manufacturing 1,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df35d4b8-5609-45e8-b842-bb0178385c99/download,,"The processing of silicon nitride (Si3N4) structural ceramics by Laminated Object
Manufacturing (LOM) using ceramic tape preforms was investigated. The key processing stages
involved green shape formation (which used the LOM process), followed by the burnout of all
organics, and final densification by pressureless sintering. Two material systems were
considered. These were a) monolithic Si3N4 and b) a preceramic polymer infiltrated Si3N4. The
raw materials for the process were tape preforms of Si3N4, which were fabricated by standard
tape casting techniques.
Mechanical property data obtained for the LOM processed Si3N4 showed high strength and
fracture toughness values. The room temperature and high temperature (1260 o
C) flexural
strengths were in the range of 700-900 MPa and 360-400 MPa, respectively. The fracture
toughness averaged from 5.5-7.5 MPa.m1/2. These strength and fracture toughness values are
comparable to those reported for conventionally prepared Si3N4 ceramics. Thus, this research
demonstrated that the LOM technique is a viable method for preparing functional Si3N4 ceramics
with good physical and mechanical properties.",,,,,,
"['Birmingham, B.R.', 'Marcus, H.L.']",2018-05-03T19:54:05Z,2018-05-03T19:54:05Z,1993,Mechanical Engineering,doi:10.15781/T2CF9JQ5T,http://hdl.handle.net/2152/65073,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'Selective Laser Reaction Sintering', 'SLRS']",Solid Freeform Fabrication of Silicon Carbide Shapes by Selective Laser Reaction Sintering (SLRS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/a946f4f9-d76e-4dcf-884d-be3b8a6aa88a/download,,"This paper describes an investigation ofthe production ofsilicon carbide shapes by
Selective Laser Reaction Sintering (SLRS). One type ofSLRS process, which combines
laser sintering of silicon with acetylene decomposition, is briefly outlined, and the
mechanisms important to the process are discussed. A series oftest shapes are made at
different acetylene pressures to determine pressure effects on conversion to silicon
carbide. X-ray diffraction spectroscopy is used for bulk analysis ofthe shapes, and Auger
electron spectroscopy is used for surface analysis. The results indicate that acetylene
pressure does have a strong effect on silicon conversion to silicon carbide, and SLRS can
be used successfully to make silicon carbide shapes.",,,,,,
"['Marcus, H.L.', 'Birmingham, B.R.']",2018-11-08T15:21:39Z,2018-11-08T15:21:39Z,1995,Mechanical Engineering,doi:10.15781/T23N2106M,http://hdl.handle.net/2152/69886,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLRS', 'ceramic materials', 'sintering']",Solid Freeform Fabrication of Silicon Nitride Shapes by Selective Laser Reaction Sintering (SLRS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/0babd20e-fb32-4f2d-a7c0-16a4be646f1a/download,,"SelectiveLaser ReactionSinteringis a variation ofselective laser sintering (SLS) that incorporates
anjn~situreaction underthe·scannedbeamtofabricate shapes from materials not directly accessible by
traditional SLS. Thispaperclescribesaninvestigation into the production of silicon nitride (Si3N4) shapes
by lasersinteringsiliconpowderinanammonia (NH3) atmosphere. The effect of gas pressure and the
importance of gas/laserinteractionsarediscussed. Single and multiple layer shapes are fabricated. The
material is analyzed by x~ray diffraction spectroscopy (XRDS) for phase content and scanning electron
microscopy (SEM) for macrostructure. Data is presented that demonstrates conversion rates from silicon to
silicon nitride on the order of 85%.",,,,,,
"['Lipton, Jeffrey Ian', 'Tow, Adam Perry', 'Burbank, Istavan', 'Vazquez, Andre', 'Lipson, Hod']",2021-10-18T20:55:44Z,2021-10-18T20:55:44Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89243,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'soft tissue simulators', 'hypodermic needle stick', 'injection force', 'medical training', 'surgical planning']",Solid Freeform Fabrication of Soft Tissue Simulators for Needle Injection,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc45fa48-d324-409d-aae9-70f202e21548/download,University of Texas at Austin,"Medical training and surgical planning are becoming important applications for Solid Freeform Fabrication
(SFF). To date, the vast majority of these training applications have relied on the production of stiff
materials to replicate bones. Others have used soft materials to replicate soft tissues without regard for
replicating the mechanical properties of the tissues. Varying the Young’s Modulus of a printed object using
various propriety materials and processes, we were able to replicate the injection force profile of a sharp
hypodermic needle stick using blunted needles safer for training usage. The composite structures and needle
pairs have a puncture force of 2.8 Newtons at a depth of 9 - 15mm, within the reported range for human
skin. This will provide a safer training alternative in the use of hypodermic needles without the need for
training on humans or animals.",,,,,,
"['Lobovsky, Maxim', 'Lobovsky, Alexander', 'Behi, Mohammad', 'Lipson, Hod']",2020-03-10T17:34:55Z,2020-03-10T17:34:55Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80235', 'http://dx.doi.org/10.26153/tsw/7254']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Solid Freeform Fabrication of Stainless Steel Using Fab@Home,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc6fecb3-5df6-4fe5-84ef-c21d3e29bf6f/download,,"Metal or ceramic parts can be solid freeform fabricated (SFF) using powdered material
processing techniques. A slurry of the powdered material is deposited in a layer-by-layer
fashion, and then sintered. We demonstrate this process using a 17-4 PH stainless steel slurry
deposited via robotically controlled syringe in the low-cost Fab@Home rapid prototyper.
Completed parts had densities as high as 90% volume fraction and tensile strength as high as
35% of the pure solid. Details of the process as well as a number of samples of different
geometries are shown.",,,,,,
"['Luo, J.', 'Gilbert, L.J.', 'Qu, C.', 'Morrow, B.', 'Bristow, D.A.', 'Landers, R.G.', 'Goldstein, J.', 'Urbas, A.', 'Kinzel, E.C.']",2021-10-19T18:07:19Z,2021-10-19T18:07:19Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89313,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'fused quartz', 'filament fed process', 'glass filaments', 'Solid Freeform Fabrication']",Solid Freeform Fabrication of Transparent Fused Quartz Using a Filament Fed Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b78a81b8-0c6d-4c73-9ae3-fce59b142771/download,University of Texas at Austin,"Glass is a critical material for many scientific and engineering applications including
optics, communications, electronics, and hermetic seals. Despite this technological relevance,
there has been minimal research toward Additive Manufacturing (AM) of glass, particularly
optically transparent glass. Additive Manufacturing of transparent glass offers potential
advantages for lower processing costs for small production volumes, increased design freedom,
and the ability to locally vary the optical properties of the part. Compared to common soda lime
glass, fused quartz is better for AM since it has lower thermal expansion and higher index
homogeneity. This paper presents a study of additive manufacturing of transparent fused quartz
by a filament fed process. A CW CO2 laser (10.6 µm) is used to melt glass filaments layer by
layer. The laser couples to phononic modes in the glass and is well absorbed. The beam and melt
pool are stationary while the work piece is scanned using a standard lab motion
system. Representative parts are built to explore the effects of variable laser power on the
properties of printed fused quartz. During printing the incandescent emission from the melt pool
is measured using a spectrometer. This permits process monitoring and identifies potential
chemical changes in the glass during printing. After deposition, the printed parts are polished and
the transmission measured to calculate the absorption/scattering coefficient. Finally, a low-order
thermal analysis is presented and correlated to experimental results, including an energy balance
and finite volume analysis using Fluent. These results suggest that optical quality fused quartz
parts with low absorption and high index of refraction uniformity may be printed using the
filament-fed process.",,,,,,
"['Crockett, R.S.', 'Gervasi, V.R.']",2019-02-19T20:32:31Z,2019-02-19T20:32:31Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73446', 'http://dx.doi.org/10.26153/tsw/598']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'stereolithography']",Solid Freeform Fabrication Research In Engineering Education,Conference paper,https://repositories.lib.utexas.edu//bitstreams/98cea85e-458a-480d-8188-d9eba885d02f/download,,"Because Solid Freeform Fabrication (SFF) has an extremely wide range of potential applications,
crossing traditional engineering and science boundaries, it is a technology that lends itself to
multi-disciplinary activities and projects. SFF is an ideal mechanism to present scientific
concepts including materials science and mechanics, as well as larger-scope engineering topics
such as agile manufacturing. At Milwaukee School of Engineering (MSOE), we are using SFF
technologies as a means to teach engineering concepts to undergraduate students through multidisciplinary research.
MSOE was awarded a five-year grant under the NSF Research Experiences for Undergraduates
Program (EEC-9619715) to facilitate student exploration in the field of Solid Freeform
Fabrication. Sixty undergraduates will participate in summer and academic year programs by the
year 2001. Eighteen students from around the country have participated in the program to date,
bringing with them a diverse background of university experience, skill level, and interests.
Working closely with a faculty advisor possessing expertise in a particular research area, they
have performed research on Solid Freeform Fabrication applications in the biomedical,
aerospace, architectural, manufacturing, and electronics industries.
Some ofthe keys to the success of this program include:
• Hands-on access to Solid Freeform Fabrication equipment through the facilities
ofthe MSOE Rapid Prototyping Center (SLA 250, LOM 2030, and FDM 1650).
• Close partnerships of the students with faculty and industry mentors in
specialized areas of expertise.
• Teaming with other educational institutions.
• Significant cross-pollination between projects; faculty from diverse
departments.
• Encouraging students to publish and present results at national conferences and symposia.",,,,,,
"Marcus, Harris L.",2021-10-12T19:22:43Z,2021-10-12T19:22:43Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88724', 'http://dx.doi.org/10.26153/tsw/15658']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Solid Freeform Fabrication', 'Solid Freeform Fabrication Symposium', 'Austin']","Solid Freeform Fabrication Symposium, An Overview",Conference paper,https://repositories.lib.utexas.edu//bitstreams/4499367b-2f34-4ab2-8b62-2715b292c718/download,University of Texas at Austin,,,This paper provides a brief overview of the annual Solid Freeform Fabrication Symposium as of 2014.,,,,
"Beaman, Joseph J.",2019-10-18T17:09:28Z,2019-10-18T17:09:28Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76265', 'http://dx.doi.org/10.26153/tsw/3354']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Solid Freeform Fabrication: An Historical Perspective,Conference paper,https://repositories.lib.utexas.edu//bitstreams/10f15bee-4273-4a94-9bb9-b0e9d2bcd819/download,,,,,,,,
"['Kumar, Vinod', 'Dutta, Debasish']",2018-12-07T16:02:42Z,2018-12-07T16:02:42Z,1997,Mechanical Engineering,doi:10.15781/T2RX9405P,http://hdl.handle.net/2152/71440,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SFF']",Solid Model Creation for Materially Graded Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bee6046c-e100-4ecc-bad8-d3a67d392484/download,,"Materially graded objects are objects composed of different constituent materials and could
exhibit continuously varying composition and/or microstructure [1][2]. Such continuous changes
results in gradation in their properties and distinguish them from objects made of conventional
composites. They are also known as heterogeneous objects, functionally graded/gradient materials
(FGM) and multi-material objects/structures [1]. In this paper, we use the terms ""materially
graded objects"" and ""heterogeneous objects"" interchangeably. Recently, heterogeneous objects
have found use in several engineering applications. The fabrication process that has shown potential
to manufacture heterogeneous objects is called Solid Freeform Fabrication (SFF), also known
as Layered Manufacturing (LM) [3][4]. SFF is a material deposition process in which the material
deposition can be controlled to vary the material composition throughout an object, thus fabricating
a materially graded object.
All SFF technologies are computer-based and require the CAD model ofthe object to be manufactured.
However, current CAD systems are capable of representing only the geometry/topology
information. Therefore, heterogeneous objects are fabricated using SFF by manually feeding
the material information along with the geometry data. This is a cumbersome process and leads to
the under-utilization ofthe SFF process. An assessment of existing representations for SFF is presented
in [5] highlighting the need for CAD models which represent material information along
with the geometry data of the object.",,,,,,
"['Baumgardner, Owen', 'Blake, Paul']",2018-04-12T17:23:16Z,2018-04-12T17:23:16Z,1990,Mechanical Engineering,doi:10.15781/T2BV7BC3Z,http://hdl.handle.net/2152/64270,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Texas Instruments Incorporated', 'defense systems', 'electronics group', 'SLA']",Solid Modeling and Stereolithography as a Solid Freeform Fabrication Technique at Texas Instruments Incorporated,Conference paper,https://repositories.lib.utexas.edu//bitstreams/85290cdf-a0db-4891-9a75-afc4d1420b11/download,,"Over the past 25 years, the CAE/CAD/CAM industry has developed technological advances that
have provided industrial users the ability to increase productivity and decrease the cycle time necessary
for product development. These technologies include basic wireframe and surface design, specializedapplication
software packages, finite element analysis, numerical control, solid modeling, and rapid
prototyping.
Each of these technologies plays a significant role in industry today. The Defense Systems & Electronics
Group of Texas Instruments currently uses these technologies in the mechanical design engineering
process. This paper discusses the two specific technologies of solid modeling and rapid prototyping
(specifically stereolithography), including their advantages, benefits, and practical applications within the
Texas Instruments Defense Systems & Electronics Group. This paper also discusses the use of
stereolithography (SLA) rapid~prototype parts within the solid-mold investment~casting process.",,,,,,
"Partanen, Jouni P.",2018-11-14T19:51:48Z,2018-11-14T19:51:48Z,1996,Mechanical Engineering,doi:10.15781/T2X34NB7Q,http://hdl.handle.net/2152/70259,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'stereolithography', 'protoyping']",Solid State Lasers for Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aedf9b8a-8fba-47f7-a4dd-ee911546c64e/download,,"Stereolithography is a Rapid Prototyping & Manufacturing (RP&M) technique which is
used to produce 3 dimensional plastic parts directly out computer files generated by CAD.
Stereolithography systems use ultraviolet lasers to solidify liquid resin into the desired form as
defined by the CAD file. In recent years, solid state laser technology has reached the point where
it can be applied to stereolithography (SL). Frequency tripling of the powerful lines of diode
pumped NdlYAG, Nd/YV04, and Nd/YLF lasers results in wavelengths of 355 nm (YAG,
YV04), 351 nm (YLF), and 349 nm (YLF). All these lines are applicable for SL. Commercial
diode pumped lasers with tens or even hundreds milliwatts in the ultraviolet are already
available. Efficient frequency tripling of the Nd/YAG, Nd/YV04 , or Nd/YLF lasers requires
pulsed operation. The pulse repetition rates at maximum average power are typically between 1
and 30 kHz. This talk describes the issues relating to the applications of pulsed all solid state
lasers in SL.",,,,,,
"['DuPont, J.N.', 'Nawrocki, J.G.', 'Griffith, M.L.']",2019-10-18T14:39:51Z,2019-10-18T14:39:51Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76226', 'http://dx.doi.org/10.26153/tsw/3315']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Net Shaping,Solidification Modeling and Microstructural Characterization of Alloy IN718 Deposited by Laser Engineered Net Shaping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/16245963-6821-4260-8f9e-c57e1dcb6285/download,,"Alloy IN718 deposited by the LENS process was characterized using light optical, and
scanning and transmission electron microscopy techniques. The as-solidified microstructure
contained primary γ−austenite cells with intercellular NbC and Laves phases. Underlying layer
microstructures were not altered by the thermal cycles of subsequent passes. Dendrite tip
modeling calculations provided a reasonable estimate of cell core compositions measured
experimentally by analytical electron microscopy techniques and were used to demonstrate that
dendrite tip undercooling was not significant under the deposition conditions employed.
Preliminary guidelines on solidification conditions required to suppress microsegregation during
LENS deposition of IN718 are provided from the modeling results. A solute redistribution model
was employed, which accurately described the solidification reaction sequence and resultant
phases present in the final microstructure.",,,,,,
"['Ramos Grez, Jorge A.', 'Bourell, David L.']",2020-02-13T19:05:13Z,2020-02-13T19:05:13Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79960', 'http://dx.doi.org/10.26153/tsw/6985']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Solidification Morphology Analysis,Solidification Morphology Analysis of SLM of Cu Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f4850a50-70d3-404a-8a9b-9053c4b3ba8f/download,,"The solidification morphology analysis of fine Cu powder melted by a raster
scanned energy beam from a focused Nd:YAG laser is presented here. The powder was
processed inside of sealed chamber where it was subjected to a high vacuum cycle. The
laser fusion process consisted raster scanning a narrow rectangular pattern with a high
density of scanning lines, the chamber was purged with inert gas during the process. Up
to a 3.3 mm/s laser travel speed and maximum laser power level of 240 W were used to
melt a 2 mm thick bed of loose powder. The resulting solidified ingots were separated
into categories based on their shape integrity. Metallographic analysis by means of
optical microscopy and scanning electron microscopy was performed on the cross section
and longitudinal section of the ingots with homogeneous surface and complete shape
integrity. Characterization revealed an elongated columnar grain structure with a grain
orientation along the direction of the laser travel direction, some degree of porosity was
observed too in some of the specimens. It was observed that grains diameter ranged from
10 to 100 µm and contained a two phase eutectic microstructure of copper and it oxides.
Oxygen content was accounted from a 5.5 up to 8.1 atomic percent, a small percentage of
chlorine was present, too. A 2 to 8 percent variation in the Vickers microhardness values
were found between the different specimens when measured along the longitudinal
section. These HV values corresponded to approximate 20-25% cold rolled oxygen free
copper (80-90 HV). The ingots thus produced suggest that a multilayer structure from Cu
powder could be build by the SLM process having sufficiently adequate compositional,
microstructure and mechanical properties for functional applications.",,,,,,
"['Shimono, Yusuke', 'Oba, Mototeru', 'Nomoto, Sukeharu']",2021-11-11T16:50:06Z,2021-11-11T16:50:06Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90246', 'http://dx.doi.org/10.26153/tsw/17167']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['multi-phase field method', 'thermal analysis', 'soldification', 'microstructure', 'titanium alloys', 'direct energy deposition']",Solidification Simulation of Direct Energy Deposition Process by Multi-Phase Field Method Coupled with Thermal Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a72fecc6-07d2-47fc-8b2c-64decd64b75a/download,University of Texas at Austin,"The multi-phase field method coupled with the thermodynamics database of calculation of phase diagrams
has been successfully applied to simulation of solidification microstructure evolutions in engineering casting
processes. As multi-phase field method is based on the local (quasi-)equilibrium assumption in solidification
theory [1], applying this method to solidification of additive manufacturing processes is not studied enough
because of extremely large cooling rate and temperature gradient conditions. On the other hand, some researchers
have reported experimental observations of the columnar-to-equiaxed transition in the solidification of the
additive manufacturing processes including the direct energy deposition. They suggest that the local
(quasi-)equilibrium assumption can be applied to solidification of additive manufacturing processes [2]. In this
study, solidification microstructures of titanium alloys in direct energy deposition are calculated by multi-phase
field method. Temperature distributions obtained by thermal analyses using finite element method are adapted to
multi-phase field method. The microstructure evolution of columnar-to-equiaxed transition is confirmed. The
results are summarized in a solidification map for direct energy deposition process conditions.",,,,,,
"['Mtikela*, I.', 'Dolenc, A.']",2018-05-03T18:12:33Z,2018-05-03T18:12:33Z,1993,Mechanical Engineering,doi:10.15781/T2GB1Z108,http://hdl.handle.net/2152/65049,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['CAD systems', '3D Models', 'Rapid Prototyping Techniques', 'RPT']",Some Efficient Procedures for Correcting Triangulated Models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/70f8b4a6-0971-44a0-8e41-f4c6abdd7de4/download,,"This paper describes methods for handling efficiently a large class of problems encountered when
dealing with 3D models represented by a collection of triangles in STL format. In spite of its drawbacks,
the STL format has become a de facto industrial standard for transferring models to manufacturing
processes generally known as Rapid Prototyping Techniques (RPT) or Solid Freeform Fabrication (SF2).
As the accuracy and size of the workspace of such processes increases, so does the size of the models one
wishes to manufacture. Therefore, the efficiency of application programs is an important consideration.
Previous published work has focused on the problem of eliminating gaps in triangulated models. In
addition to efficiency, this paper descrihes methods for dealing with other problems such as overlapping
triangles and intersecting triangles. The algorithms have been implemented and tested in industry. The
underlying data structures hased on adaptive space subdivision also allow the development of other
efficient tools such as slicing.",,,,,,
"['Fischer, M.', 'Schöppner, V.']",2021-10-11T22:52:41Z,2021-10-11T22:52:41Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88675', 'http://dx.doi.org/10.26153/tsw/15609']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'Ultem*9085', 'surface-smoothing', 'high-energy finishing']",Some Investigations Regarding the Surface Treatment of Ultem*9085 Parts Manufactured with Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e12b0b1a-3964-49c1-9b97-b6e3b0aad8c6/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) parts are typically subject to process-related rough or
wavy surfaces, with stair-stepping effects whenever the parts produced have sloped or rounded
part geometries; however, the level of optical quality frequently required demands that parts
feature a smooth surface. In this paper, the results of a high-energy finishing process, which uses
a disc finishing unit and is designed for parts manufactured with the material Ultem*9085, are
presented. The analysis discusses the surface-smoothing effect of various finishing materials with
varying geometries, as well as the effect of finishing time and speed. Additionally, the efficiency
of the surface treatment has been analyzed specifically at corners, edges and in cavities.",,,,,,
"['Norazman, Farhana', 'Smith, Patrick', 'Hopkinson, Neil']",2021-10-28T21:34:04Z,2021-10-28T21:34:04Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89704,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['spectral irradiance', 'sintering lamps', 'infrared lamps', 'high speed sintering']",Spectral Analysis of Infrared Lamps for Use in the High Speed Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/86c4b0a9-b334-468a-8bef-03fe3802f5c5/download,University of Texas at Austin,"High Speed Sintering (HSS) is an additive manufacturing (AM) process that utilizes a
combination of inkjet printing and infrared heating to create three dimensional objects from
polymer powder. The interaction between the ink, sintering lamp and powder is pivotal in
promoting the optimum sintering behavior required to ensure the high dimensional accuracy
and strength of parts. This paper investigates the relationship between the spectral irradiance
of sintering lamps and the mechanical properties of high speed sintered parts. Nylon-12 parts
were manufactured using two different infrared lamps. Ultimate tensile strength, Young’s
modulus and elongation at break of the manufactured parts were determined. Densities of parts
were calculated while porosities were measured using micro-computed tomography.
Irradiances of the IR lamps were measured and their spectra analyzed. Results show that the
parts manufactured using the high irradiance lamp had better tensile properties, and lower
density and porosity compared to the low irradiance lamp.",,,,,,
"['Kamilis, D.', 'Lee, S.', 'Desjardins, J.', 'Polydorides, N.']",2021-11-16T16:28:00Z,2021-11-16T16:28:00Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90335', 'http://dx.doi.org/10.26153/tsw/17256']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['discrete tomography', 'spectral X-ray CT', 'non-destructive testing']",Spectral X-ray CT for Fast NDT Using Discrete Tomography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50fbbf0c-6ac8-4079-bd4d-5d939b289cb7/download,University of Texas at Austin,"We present progress in fast, high-resolution imaging, material classification, and fault detection using
hyperspectral X-ray measurements. Classical X-ray CT approaches rely on data from many projection
angles, resulting in long acquisition and reconstruction times. Additionally, conventional CT cannot
distinguish between materials with similar densities. However, in additive manufacturing, the majority of
materials used are known a priori. This knowledge allows to vastly reduce the data collected and increase
the accuracy of fault detection. In this context, we propose an imaging method for non-destructive testing
of materials based on the combination of spectral X-ray CT and discrete tomography. We explore the
use of spectral X-ray attenuation models and measurements to recover the characteristic functions of
materials in heterogeneous media with piece-wise uniform composition. We show by means of numerical
simulation that using spectral measurements from a small number of angles, our approach can alleviate
the typical deterioration of spatial resolution and the appearance of streaking artifacts.",,,,,,
"['Hauser, C.', 'Sutcliffe, C.', 'Egan, M.', 'Fox, P.']",2020-02-20T19:08:28Z,2020-02-20T19:08:28Z,2005,Mechanical Engineering,,https://hdl.handle.net/2152/80040,eng,2005 International Solid Freeform Fabrication Symposium,Open,Spiral growth manufacturing,Spiral Growth Manufacturing (SGM) – A Continuous Additive Manufacturing Technology for Processing Metal Powder by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4da2dda0-6b58-43b1-b3b3-38b105a88f4e/download,,"Spiral growth manufacturing is a new innovative powder based rapid manufacturing
technique. The innovation exists in the methodology in which powder layers are deposited.
Unlike other pre-placed powder systems, the deposited layers move relative to the location at
which they are processed. This is made possible by a rotating build drum into which powder is
deposited, in spiralled layers, from a stationary hopper. With this configuration powder can be
continuously deposited and levelled and simultaneously processed, eliminating delays in the
build cycle. Stainless steel and cobalt-chrome powder is selectively melted using a 100W flash
lamp pumped Nd:YAG laser. This paper reports on factors affecting build rate and on build
strategies for creating a number of axis-symmetric thin and thick walled cylinders. Experimental
results suggest that build rate for thin walled structures bonded to a substrate will ultimately be
governed by tangential movements of the powder particles when frictional forces are not
sufficient to accelerate the particles along a curved path, provided that enough laser power is
available for melting. Even melt pool balling, which is evident when melting one layer at high
speeds, diminishes in multiple layer builds due to re-melting and infilling.",,,,,,
"['Ghayad, Ibrahim M.', 'Geiss, Erik', 'Crocker, James E.', 'Marcus, Harris L.']",2019-10-09T16:36:43Z,2019-10-09T16:36:43Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76161', 'http://dx.doi.org/10.26153/tsw/3250']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Ceramics,Spot Joining of Si3N4 and SIC Ceramics using Selective Area Laser Deposition (SALD) Technique,Conference paper,https://repositories.lib.utexas.edu//bitstreams/88df9f10-6f57-4206-bcf3-bdd5abcc2f8b/download,,,,,,,,
"['Fussell, P.S.', 'Kirchner, H.O.K.', 'Prinz, F.B.']",2018-09-26T20:14:09Z,2018-09-26T20:14:09Z,1994,Mechanical Engineering,doi:10.15781/T2J38M29S,http://hdl.handle.net/2152/68593,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['thermal spray deposition', 'stereolithography', 'rapid tooling']",Sprayed Metal Shells for Tooling: Improving the Mechanical Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c85d4ff-37d5-4a20-9cf2-4c86ff567be7/download,,"Tbis work describes methods to improve the quality of the metal resulting from thermal spray deposition,
including both the mechanical and metallurgical behavior. The engineering context is the
production of sprayed metal shells suitable for tooling applications. The sprayed metal shells are
mechanically dominated by interparticle interfaces; the particles are largely mechanically interlocked
with very little metallurgical bonding. Based on these observations, improvements are
made to these interfaces, and the measure of the improvement is shown in mechanical tests.",,,,,,
"['Bayazitoglu, Kaya J.', 'Cassoli, Matthew', 'Beaman, Joseph J.', 'Kovar, Desiderio']",2024-03-26T21:54:59Z,2024-03-26T21:54:59Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124428', 'https://doi.org/10.26153/tsw/51036']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['selective laser flash sintering', 'aluminum', 'alumina powder', 'additive manufacturing']",Spreading and Packing of Alumina Powder Using a Displacement-controlled Roller in SLFS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0acfcae7-4f12-41e0-b100-45e3c4055da1/download,University of Texas at Austin,"Selective laser flash sintering (SLFS) is a powder bed fusion process that enables direct
additive manufacturing of ceramics. Similar to other powder bed fusion processes, the density of
the ceramic powder bed impacts attainable density of the final part. Experiments were conducted
using a spray-dried alumina powder that was spread and then packed using a displacementlimited roller. The spreadability of the powder was visually assessed. The microstructure of the
resulting compacted powder was compared to a traditional method of pressing ceramic powder
into a pellet using a die and hydraulic press. Packed regions were sintered to final density and
compared in a scanning electron microscope to samples hydraulically pressed at known pressure
to evaluate the efficacy of a roller-based packing process.",,,,,,
"['Vaughan, D.M.', 'Nycz, A.', 'Noakes, M.W.', 'Masuo, C.']",2021-11-17T23:47:07Z,2021-11-17T23:47:07Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90359', 'http://dx.doi.org/10.26153/tsw/17280']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['process development', 'process parameters', 'process characteristics', 'stainless steel 410', 'wire-arc deposition']",SS410 Process Development and Characterization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/396d9bfc-c08b-4eaf-a0cc-27d688a70ee0/download,University of Texas at Austin,"Wire-fed stainless-steel additive manufacturing provides the potential for an
alternative to traditional stainless-steel tool making processes. 410 stainless steel
provides the necessary hardness for long term tool use and its corrosion resistances
negates the need for post processing of non-critical faces. 410 has unique
characteristics that require different design and welding parameters from other
materials. This paper will look at the parameters and characteristics to expect when
using wire-arc deposition for 410 stainless steel. Individual weld beads and simple
geometric features were printed using the mBAAM wire-arc system at ORNL to
determine effective wire-arc parameters for SS410. Once parameters were chosen,
additional features were printed to determine the geometric characteristics of printed
SS410 as well as compare the differences between designed geometries and printed
geometries. These results allow for the formulation of smarter design rules when
designing parts for SS410 additive manufacturing.",,,,,,
"['Sojiphan, K.', 'Sriraman, M.R.', 'Babu, S.S.']",2021-09-30T15:18:12Z,2021-09-30T15:18:12Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88262', 'http://dx.doi.org/10.26153/tsw/15203']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Very High Power Ultrasonic Additive Manufacturing', 'microstructural stability', 'aluminum parts']",Stability of Microstructure in Al3003 Builds Made by Very High Power Ultrasonic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eadb8eaa-58e3-4dc9-8f9d-e0bc50f16d18/download,University of Texas at Austin,"Very High Power Ultrasonic Additive Manufacturing (VHP-UAM) system was used to
produce aluminum parts from 150 µm thick Al3003-H18 foils. The build was processed at 36 μm
vibration amplitude, 8 kN normal load, and 35.6 mm/s weld speed at 20 kHz frequency. Almost
100% linear weld density was achieved. A deformation-interaction volume of ~20 μm was
observed below the bonded interface. The microstructural stability including grain boundary
structures, and crystallographic orientations was evaluated after annealing these samples at
343oC for 2 hours and 450oC for 2 hours. After heat treatment, small grains persisted at the
interfaces with sluggish grain growth kinetics. In contrast, normal grain growth kinetics was
observed in the middle of the foils. Possible mechanisms for such phenomena are discussed.",,,,,,
"['Williams, G.T.', ""O'Brien, J.F."", 'Mezghani, A.', 'Eachus, M.J.', 'Meisel, N.A.', 'McComb, C.C.']",2021-11-18T16:57:18Z,2021-11-18T16:57:18Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90427', 'http://dx.doi.org/10.26153/tsw/17348']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['mesostructure patterns', 'mesostructure', 'additive manufacturing', 'standardized framework']",A Standardized Framework for Communicating and Modeling Parametrically Defined Mesostructure Patterns,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb4b366e-8253-4212-995c-c9e0e699fafe/download,University of Texas at Austin,"Intricate mesostructures in additive manufacturing (AM) designs can offer enhanced strength-to-weight performance. However, complex mesostructures can also hinder designers, often
resulting in unpalatably large digital files that are difficult to modify. Similarly, existing methods
for defining and representing complex mesostructures are highly variable, which further increases
the challenge in realizing such structures for AM. To address these gaps, we propose a standardized
framework for designing and representing mesostructured components tailored to AM. Our
method uses a parametric language to describe complex patterns, defined by a combination of
macrostructural, mesostructural, and vector field information. We show how various
mesostructures, ranging from simple rectilinear patterns to complex, vector field-driven cellular
cutouts can be represented using few parameters (unit cell dimensions, orientation, and spacing).
Our proposed framework has the potential to significantly reduce file size, while its extensible
nature enables it to be expanded in the future.",,,,,,
"['Joy, Ranjit', 'Wu, Sung-Heng', 'Tariq, Usman', 'Mahmood,  Muhammad Arif', 'Isanaka, Sriram Praneeth', 'Malik, Asad Waqar', 'Liou, Frank']",2024-03-26T22:48:05Z,2024-03-26T22:48:05Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124430', 'https://doi.org/10.26153/tsw/51038']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['secure distributed digital factory', 'additive manufacturing', 'subtractive manufacturing', 'challenges with distributed digital factory', 'scalability and interoperability']","State-of-the-art Cyber-enabled Physical and Digital Systems Deployed in Distributed Digital Factory Using Additive and Subtractive Manufacturing Systems: Open, Scalable, and Secure Framework",Conference paper,https://repositories.lib.utexas.edu//bitstreams/573f88d1-f450-4a5d-91c5-aacc0571ce0f/download,University of Texas at Austin,"A distributed digital factory (DDF) integrates physical and digital systems, leveraging additive
manufacturing (AM) and subtractive manufacturing (SM), to enable the dispersed production of components.
Existing work focuses on digital twins, AM and SM systems, and some security aspects. Nevertheless, a holistic
view of integrating devices with dynamic provisions to invoke digital twins has limited supporting research. This
paper will detail cyber-physical and digital systems deployed in DDFs. The components of cyber systems,
including AM & SM equipment, sensors, communication protocols, and monitoring software, are covered.
Challenges associated with the design and deployment of DDFs, such as security, scalability, and interoperability,
are detailed. The assessment emphasizes an open framework for DDF development, allowing system integration
from vendors & participants across diverse locations and capabilities. The article also examines the significance
of a scalable and secure framework for the implementation of DDFs, which ensures the dependability and
availability of on-demand manufacturing.",,,,,,
"['Mulka, Nicholas', 'Goyal, Tarun', 'Jariwala, Amit', 'Rosen, David']",2021-12-07T18:43:16Z,2021-12-07T18:43:16Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90753', 'http://dx.doi.org/10.26153/tsw/17672']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['top-down stereolithography', 'support structure', 'static liquid', 'support liquid']",Static Liquid Interface to Reduce Support Structure Necessity in Top-Down Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/62bbbf89-12d0-45b3-9820-b99f6120c4c5/download,University of Texas at Austin,"Stereolithography (SLA) 3D printing is a vat photopolymerization additive
manufacturing process that utilizes photocurable resin, which requires sacrificial supporting
structures on part overhangs, increasing material waste and post-processing time. This study
details a novel process for conducting top-down SLA 3D printing from a thin resin layer located
above a static immiscible supporting fluid, which reduces or eliminates the need for solid
supports. The support fluid prevents deflection from buoyant and gravitational forces on thin
overhangs from anchored parts due to minute density differences between the supporting fluid
and cured resin, while reducing the volume of resin necessary to print compared to traditional
top-down SLA. Using this process, we have experimentally demonstrated printed geometry with
overhangs of up to 90 degrees. Additionally, necessary material properties of both fluids and
process parameters of the system have been identified for the system’s feasibility and broader
adaptation.",,,,,,
"['Smith, Tyler', 'Copenhaver, Katie', 'Lamm, Meghan', 'Brackett, James', 'Kumar, Vipin', 'Hershey, Christopher', 'Joslin, Chase', 'Lindahl, John', 'Tobin, Jim', 'Rodriguez, Brittany A.', 'Kunc, Vlastimil', 'Hassen, Ahmed']",2024-03-26T22:50:23Z,2024-03-26T22:50:23Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124433', 'https://doi.org/10.26153/tsw/51041']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'nozzle', 'short fiber', 'extrusion']",Static Mixing Nozzles for Long and Short Fiber Additive Extrusion Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c06cb946-b938-45ed-9486-4bccae347ced/download,University of Texas at Austin,"Additive manufacturing is conventionally used to create structures by extruding plastic or
metal layer by layer. In the case of polymer processes, fibers are typically added to increase stiffness and
reduce warping during building. The length of the fiber exiting the nozzle can impact the overall
mechanical properties of the structure. Using long fiber pellets can increase the starting length of the
pellets to help increase the average fiber length coming out from the extruder. However, extruded long
fiber materials tend to have low fiber alignment and high porosity leading to poor mechanical properties.
By blending long fiber and short fiber resins using a static mixing nozzle, consolidated beads can be
created to produce more stable and solid structures while adding a fixed amount of long fiber into the
extruded bead to increase mechanical performance.",,,,,,
"['Witt, Gerd', 'Sehrt, Jan T.']",2021-09-30T15:39:47Z,2021-09-30T15:39:47Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88266', 'http://dx.doi.org/10.26153/tsw/15207']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['beam melted parts', 'static strength', 'material properties', 'surface finish']",Static Strength Analysis of Beam Melted Parts Dependent on Various Elements,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d4dbe516-cb01-4161-a086-006e6447b9d3/download,University of Texas at Austin,"For the optimum design and correct use of beam melted parts extensive material
comprehension is necessary. For this reason this paper presents static strength analysis of beam
melted parts dependent on various influences such as manufacturing position and orientation,
exposure strategy and surface quality. It turned out that the anisotropic material properties can be
described by the transversal isotropy (2D) since the azimuth angle displays small dependence
especially in combination with the rotate scan strategy. In contrast to this the polar angle has the
biggest influence at all exposure strategies. Another great influence arises from the surface finish
- the better the surface finish the higher the static strength. The exposure strategies in turn have
the smallest effect on the static strength.",,,,,,
"['Murphy, J.', 'Lappo, K.', 'Wood, K.', 'Beaman, J.']",2019-10-30T16:36:44Z,2019-10-30T16:36:44Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78188', 'http://dx.doi.org/10.26153/tsw/5277']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Surface Finishing,A Statistical Model of Laser Surface Finishing Using Design of Experiments and ANOVA,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1aef07b3-dbdf-47b7-8129-a6f267eca75a/download,,"In previous work, laser polishing indirect-SLS metal parts was achieved using a Nd:YAG
laser raster scanned at high speed. This work showed surface roughness could effectively
be reduced by means of shallow surface melting. Surface area roughness data, Ra, was
obtained by line profilometry measurements of the polished samples according to a
modified procedure based on the ASME standard for surface texture measurements. A
Design of Experiments (DOE) was conducted to better understand the effects of
processing parameters such as laser beam power, scan time, and scan line density on the
surface roughness. The DOE consisted of a multi-level test for each variable and included
one replicate. ANOVA was used to determine the significance of each variable and the
interactions between variables. Three reduced order models were derived, but large
variations in absorptivity in the experiment resulted in large errors and inaccurate models.
The data did show the average reduction in roughness over all the trails was about 20%,
however several trials resulted in roughness reductions of over 50%. Future work will
concentrate on reducing the absorptivity noise to produce more accurate models.","The Laboratory of Freeform Fabrication gratefully acknowledges the support of
the Office of Naval Research for funding the project ìSurface Engineering for SFF
Processesî, Grant Nº: N00014-00-1-0334.",,,,,
"['Akande, S.O.', 'Dalgarno, K.W.', 'Munguia, J.', 'Pallari, J.']",2021-10-28T21:07:27Z,2021-10-28T21:07:27Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89701,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['quality control', 'statistical process control', 'lasers', 'sintering', 'polymer', 'impact strength']",Statistical Process Control Application to Polymer Based SLS process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8f326c7a-ce99-4b44-b653-172270feec82/download,University of Texas at Austin,"The quality of selective laser sintering (SLS) made parts is known to be influenced by
process parameters and the quality of input material. In order to ensure consistency in part
quality, there is a need to monitor the quality of parts made using the SLS machines.
Benchmark specimens were designed and manufactured to track key quality characteristics of
strength, bending stiffness, density and dimensional accuracy of parts made in multiple
builds. Using data collected from the benchmark tests, correlation analysis and statistical
process control (SPC) charts were established. SPC was found to be a useful tool that can
provide SLS users with the mean of identifying possible changes in the process. Therefore, it
can be used for process monitoring in SLS process to ensure consistency in part quality for
long term production.",,,,,,
"Gervasi, Vito R.",2018-11-28T21:30:43Z,2018-11-28T21:30:43Z,1997,Mechanical Engineering,doi:10.15781/T2XG9FX1N,http://hdl.handle.net/2152/70334,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SPC']",Statistical Process Control For Solid Freeform Fabrication Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e1db966-0f8b-4a18-a8cf-bffd6f961173/download,,"Statistical prpcess control (SPC) has not been widely used for solid freeform fabrication (SFF) pr~cesses, primarily due to the wide diversity ofgeometries in builds. In addition, typical parts created on SFF platforms are not ofsimple, nor easy-to- measure geometries, which fVrther complicates the application ofSPC. A study is currently in progress to establisq a method to apply SPC to SFF. Three SPC test parts were studied to determine the addedIbuild cost and accuracy improvement when SPC is applied to stereolithography. In this study, SPC was applied to X & Y shrinkage, and line-widthcompensation facto~s over a period oftime. IfSPC can be effectively applied, it will alert the operator to othe~seunnoticed system changes before valuable build-time is lost.",,,,,,
"['Fussell, P.S.', 'Weiss, L.E.']",2018-04-10T18:50:30Z,2018-04-10T18:50:30Z,1990,Mechanical Engineering,doi:10.15781/T26970F5X,http://hdl.handle.net/2152/64246,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['The Engineering Design Research Center', 'solid free form', 'SFF', 'SLA']",Steel-Based Sprayed Metal Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc0618e3-8930-4de2-bec5-c3f1cf7b8ef4/download,,"A strategy for building sprayed steel tooling by arc spray deposition is discussed in this paper. Depositing steel is
crucial for moving sprayed metal toolingfrom prototype applications to superior prototype and production-quality
tooling. Tooling is fabricated by spraying onto S\lbStra~S that define the tooling shell shape. In particular, two
process issues are addressed: deposition of thick metal shells, and control of oxide content by atomization with inert
gases.",,,,,,
"['Himmer, T.', 'Nakagawa, T.', 'Noguchi, H.']",2018-12-05T17:34:04Z,2018-12-05T17:34:04Z,1997,Mechanical Engineering,doi:10.15781/T2JM2424G,http://hdl.handle.net/2152/71402,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Ceramics', 'superconductivity']",Sterelithography of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a29ce521-740e-4546-b12a-cc413e5d1fa3/download,,"For studies of Stereolithography of Ceramics (SOC), a composite has been produced by
mixing ceramic powder with a photosensitive resin. To obtain high load of ceramics a
lamination preprocess was used. Then, the produced ceramic-binder films have been laminated
and selectively cured in a Stereolithography machine. After cleaning, the green bodies were
fired to burn out the binder and afterwards sintered to achieve full strength.",,,,,,
"['Liu, Renwei', 'Wang, Zhiyuan', 'Sparks, Todd', 'Liou, Frank']",2021-10-19T15:31:35Z,2021-10-19T15:31:35Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89301,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['stereo vision', 'component repair process', 'titanium parts', 'Ti-6Al-4V', 'hybrid manufacturing']",Stereo Vision Based Hybrid Manufacturing of Ti-6Al-4V in Component Repair Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8c78af47-8371-4118-b881-4c19635233fe/download,University of Texas at Austin,"Parts or products from high performance metal are very expensive, partly due to the
processing complexities during manufacturing. Recent studies have indicated that hybrid
processes of additive manufacturing and machining process can be used to repair titanium parts,
thus extending the service life. In order to implement these methods automatically, it is necessary
to obtain the spatial geometry information of component with defects to generate the tool path.
The purpose of this paper is to summarize the research on hybrid manufacturing with stereo
vision function which can be applied to the component repair process. Stereo vision is adopted to
detect the location and the size of the defect area which is marked by color marker. And then
laser displacement sensor is applied to scan the defect area. Therefore, automated alignment,
reconstruction of the defect area and tool path planning could be implemented based on the
spatial geometry information. Finally, a Ti64 part repair experiment is done to verify the method.
This work provides an automatic method for repairing damaged parts by hybrid manufacturing.",,,,,,
"['Jayanthi, Suresh', 'Bokuf, Bronson', 'McConnel, Ronald', 'Speer, Robert J.', 'Fussell, Paul S.']",2018-11-30T16:14:09Z,2018-11-30T16:14:09Z,1997,Mechanical Engineering,doi:10.15781/T2QF8K479,http://hdl.handle.net/2152/70595,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Stereolithography', 'rapid prototyping']",Stereolithographic Injection Molds for Direct Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f2dc9932-8ebb-4286-8cbf-a28302b2b1a2/download,,"The use of stereolithographic core and cavity sets in low volume injection molding is
experiencing steady growth. The use of plastic instead of metal molds raises several issues in
terms ofmold handling, material injection and process cycle requirements. This study focuses on
identifying and understanding these issues and optimizing them for low volume direct tooling
applications. Some experimental observations are presented using DuPont Somos® epoxy
photopolymers and representative mold geometries which identify the critical mold properties
that influence mold life and the injection molded part quality.",,,,,,
"['Pang, Dr. Thomas H.', 'Jacobs, Dr. Paul F.']",2018-05-03T18:29:06Z,2018-05-03T18:29:06Z,1993,Mechanical Engineering,doi:10.15781/T2TM72J2B,http://hdl.handle.net/2152/65054,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'SL', 'RMS']",StereoLithography 1993: QuickCast TM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d18b28f9-bdba-4975-9ebd-609c533f72ae/download,,"Previously, StereoLithography (SL) generated solid patterns had limited success highly
accurate shell investment casting applications. The majority of the failures involved the cracking of
the ceramic investment casting shell. However, the recent invention of the QuickCast TM build-style
and the development of a new epoxy resin, XB 5170, led to an unprecedented level of success
the burnout process of SL patterns from investment casting shells. Unlike conventional
building techniques, QuickCast involves the building of SL patterns with essentially hollow
structures. When the low viscosity liquid epoxy resin is drained from the interior of the pattern,
voids are formed, allowing the cured resin to collapse inwards during the autoclave and burn-out
stages. This effectively prevents the shells from cracking as the result of outward thermal
expansion. 3D Systems formed QuickCast teams with three respected foundries to test shell
investment casting using SL patterns. A test part having relatively complex geometries a
Boeing 737 cargo door bracket) was selected. To date, this SL part has been successfully cast
aluminum, titanium, beryllium-copper, and stainless steel, with RMS surface finish as low as 1
micrometer, without any subsequent finishing operations.",,,,,,
"['Tang, Yanyan', 'Henderson, Clifford L.', 'Muzzy, John', 'Rosen, David W.']",2020-02-17T14:49:39Z,2020-02-17T14:49:39Z,9/1/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/80001', 'http://dx.doi.org/10.26153/tsw/7026']",eng,2004 International Solid Freeform Fabrication Symposium,Open,complex stereolithography,Stereolithography Cure Process Modeling Using Acrylate Resin,Conference paper,https://repositories.lib.utexas.edu//bitstreams/163929cb-80e4-4039-9073-660d74e90737/download,,"In this paper, a complex stereolithography (SL) cure process model is presented that
incorporates transient thermal and chemical effects which influence final part shape and
properties. The model incorporates photopolymerization, mass diffusion, and heat transfer.
Material properties are characterized and a comprehensive kinetic model parameterized for a
model compound system. SL process simulations are performed using finite element methods
with the software package FEMLAB, and validated by the capability of predicting the fabricated
part dimensions. A degree of cure (DOC) threshold model is proposed which can predict the cure
line size within 15% error, comparing with 30% prediction error by the exposure threshold
model currently used in SL. Furthermore, through the sensitivity analysis conducted by the
process model presented here, the sensitive parameters are identified and the SL bath
temperature, photointiator absorptivity and concentration are found to be the most sensitive
factors that affect the SL fabrication results. The sensitive variables will be the focus of further
research meant to improve SL process speed and resolution.",,,,,,
"Pang, Thomas H.",2018-05-03T16:25:07Z,2018-05-03T16:25:07Z,1993,Mechanical Engineering,doi:10.15781/T2J960T1N,http://hdl.handle.net/2152/65033,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'SL', 'QuickCast', 'SLA', '3D systems']",Stereolithography Epoxy Resin Development: Accuracy and Dimensional Stability,Conference paper,https://repositories.lib.utexas.edu//bitstreams/afff9dbe-e6c0-46dd-a437-fa9ccde78f6b/download,,,,,,,,
"Pang, Thomas H.",2018-10-03T15:34:02Z,2018-10-03T15:34:02Z,1994,Mechanical Engineering,doi:10.15781/T2S75745M,http://hdl.handle.net/2152/68648,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Stereolithography', '3D Systems', 'Dimensional stability']","Stereolithography Epoxy Resins SL 5170 and SL 5180: Accuracy, Dimensional Stability, and Mechanical Properties",Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2d91019-aac3-4378-8bc0-05692cb21ef0/download,,"Stereolithography (SL) resins based on epoxy chemistry provide significantly improved overall
part accuracy, dimensional stability, and mechanical properties relative to the earlier acrylate SL resins.
In July, 1993, epoxy-based SL 5170 resin was introduced for use on the SLA-250 system. In March,
1994, the epoxy-based resin for the SLA-500 system, SL 5180, was also released. These epoxy resins
have minima11aser-cure and post-cure shrinkage, resulting in extremely low curl and distortion. Overall
dimensional accuracy has also improved. Standard User-Parts built in SL 5170 on the SLA-250, and
now, SL 5180 on the SLA-500, have recently achieved the highest level of dimensional accuracy from a
statistically significant number of measurements taken in the x, y, and z directions. Diagnostic test results
presented in this paper show that these epoxy-based resins are now capable of producing extremely flat
parts when required. SL parts built in these resins also exhibit superb dimensional stability in the lasercured
state, as demonstrated by the ""Green"" Creep Distortion diagnostic test. Dimensional stability in the
laser-cured state is critical, especially for SL parts having the characteristic quasi-hollow internal
structure, generated using the QuickCast™ build style. Creep results are presented in this paper.
Furthermore, the overall mechanical properties of these epoxy resins were measured according to the
ASTM standards for plastics. Tensile, flexural, and impact properties for the epoxy-based and acrylatebased
SL resins are presented in this paper. Mechanical properties ofthermoplastics, acrylic plastic
(PMMA) and medium impact polystyrene, are also presented for comparison. The data shows that the
mechanical properties of epoxy-based SL 5170 and SL 5180 are comparable to, or exceed those of acrylic
plastic and medium impact polystyrene.
For applications that require greater mechanical strengths than SL 5170 and SL 5180, metal
parts can be obtained using QuickCast. QuickCast, made possible with the development of these epoxybased
SL resins, is the key to successfully utilizing SL parts for shell investment casting applications, and
the generation of precision metal components directly from SL parts. Furthermore, when a ""negative""
core and cavity pair of a part geometry is produced in metal using QuickCast, tooling is obtained.
Prototype, and eventually, production functional parts may then be ultimately injection molded in the
QuickCast tooling, using the desired engineering thermoplastic material.",,,,,,
"['Rahmati, Sadegh', 'Dickens, Philip']",2018-11-30T16:37:59Z,2018-11-30T16:37:59Z,1997,Mechanical Engineering,doi:10.15781/T2FX74J2V,http://hdl.handle.net/2152/70597,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SL', 'engineering environment']",Stereolithography Injection Mould Tool Failure Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/25173bc8-39cd-4926-9797-23e7a9a157d9/download,,"Manufacturing technology does not always enjoy the traditional cost benefits of mass
production because large quantities may not be required. Separating low cost from
high volume requires new approaches to product and process design and technology.
Stereolithography tooling supports this concept by providing tools quickly during the
design process to prove out and select optimal new concepts. The SL tooling
technique is a first step in realising the near-term objectives such as conceptual
modelling and design verification, as well as the long-term objectives in production.
At the University ofNottingham development ofthe SL injection moulding tools has
taken place along two fronts. The first to provide material data for tool design under
extreme conditions of stress and temperature; and obtaining data from different tests
carried out on simple tools which resemble real situations (Rahmati 1997). The
second development is theoretical and analytical analysis of the simple tools during
the injection process. Both ofthe above developments have ultimately been directed
towards achieving the goal of successful SL injection mould tooling. The results of
such developments may help the industry to reduce the lead time and provide a faster
technique in a concurrent engineering environment.
The first experimental resuhs proved the capabilities of the technique and
demonstrated its advantages and weaknesses. In addition, the important parameters in
SL injection moulding such as injection pressure, injection speed, injection
temperature, freeze time, cycle time etc. were investigated. The results and
derivations may be used either as an instruction guide for industry users to design SL
injection tools, or to provide design information for particular conditions and to
predict tool failure.",,,,,,
"['Jackson, Ian', 'Xiao, Huinian', 'Ashtiani, Mansour', 'Berben, Luc']",2018-11-08T19:06:48Z,2018-11-08T19:06:48Z,1996,Mechanical Engineering,doi:10.15781/T2959CT3R,http://hdl.handle.net/2152/69903,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'structures', 'model fabrication']",Stereolithography Model in Presurgical Planning of Craniofacial Surgery,Conference paper,https://repositories.lib.utexas.edu//bitstreams/320c0488-6121-41d4-998a-ad8c694fc852/download,,"A rapid prototyping technique, which was originally used in mechanical engineering, has
found applications in medicine. Recently stereolithographic models have been used in
complex craniofacial surgeries for visualization, presurgical planning and implant design[ 1-
4]. There are some advantages ofmodel fabrication when preparing for surgery: more
accurate evaluation ofthe patient's condition/deformities, better informed consent for
surgery and better-fitting artificial body parts. This paper is a case report in which a
sterelithographic skull model was used in the presurgical planning of a complex
craniofacial tumor resection",,,,,,
"['Srisawadi, S.', 'Lapapong, S.', 'Dokkhan, S.', 'Wiroonpochit, P.']",2021-11-18T01:53:48Z,2021-11-18T01:53:48Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90402', 'http://dx.doi.org/10.26153/tsw/17323']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['natural rubber latex', 'highly elastic parts', 'stereolithography', 'additive manufacturing']","Stereolithography of Natural Rubber Latex, a Highly Elastic Material",Conference paper,https://repositories.lib.utexas.edu//bitstreams/6c1f3d97-c8f5-4344-be29-5b4e2cf7b97c/download,University of Texas at Austin,"Typically, natural rubber (NR) offers a wide range of applications because of its exceptional
mechanical properties, particularly elasticity. However, due to its unique mechanism of
vulcanization, 3D fabrication techniques with NR is still to be explored. Vulcanization is necessary
to form crosslinks between the NR chains and greatly improve its elasticity and tensile strength.
In this study, the pre-vulcanized NR latex was prepared for the stereolithography (SLA) process
to additively manufacture highly elastic parts. Process parameters were studied to investigate the
feasibility of the fabrication. The parameters include laser power, scan speed, and layer thickness.
This work demonstrates a promising 3D fabrication technique using the NR latex that achieves
mechanical properties and crosslink density comparable to those from the conventional processes.",,,,,,
"['Sager, Benay', 'Rosen, David']",2019-10-30T16:34:16Z,2019-10-30T16:34:16Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78187', 'http://dx.doi.org/10.26153/tsw/5276']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Stererolithography,Stereolithography Process Resolution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2b70211-7d88-4d5a-8e57-ab99c6d5183f/download,,"To build smaller parts in StereoLithography (SL) and detect some build errors before
fabrication, a good understanding of process resolution is needed. A categorization of resolution
factors into process-inherent and software-induced categories is presented in the paper. Results
from several experiments testing different aspects of SL resolution illustrate the effects of these
factors. A method based on offsetting algorithms is presented to determine as-built part crosssections and aid detection of possible build errors. A method that will enhance build resolution
of SL parts is proposed.",,,,,,
"['Marutani, Yoji', 'Kamitani, Takayuki']",2018-11-14T17:48:49Z,2018-11-14T17:48:49Z,1996,Mechanical Engineering,doi:10.15781/T2QJ78H94,http://hdl.handle.net/2152/70250,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'LOM', 'UV laser']",Stereolithography System Using Multiple Spot Exposure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/56ee007a-5c32-44a9-b756-ef9714557382/download,,"A new method ofmaking 3-D objects is proposed. A discharge lamp is used as a UV
light source, and to make the fabrication time shorter, multiple spots exposure using optical
fibers is employed. The light is distributed to some optical fibers. The output side of each fiber
is arrayed linearly and the emitted lights are focused on the surface ofthe photosensitive resin.
As the fiber array is raster-scanned, the light transmission of each fiber is controlled by the
optical shutter independently according to the pixel data at the corresponding position to be
irradiated. Small-sized stereo-lithography systems can be realized economically by this
method.",,,,,,
"['Catalanotto, A.M.', 'Ware, L.G.', 'Chagolla, J.A.', 'Suzuki, D.H.', 'Cordero, Z.C.']",2021-11-09T16:31:05Z,2021-11-09T16:31:05Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90106', 'http://dx.doi.org/10.26153/tsw/17027']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['directionally solidified castings', 'shell molds', 'positives', '3D printing', 'stereolithography']",Stereolithography-Based Manufacturing of Molds for Directionally Solidified Castings,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f67630f3-0446-44b1-b501-83ddd2e3c10e/download,University of Texas at Austin,"Directionally solidified components, such as single crystal turbine blades, are
typically grown using shell molds prepared using a lost wax process that begins with injection-molded wax positives. These positives have complex designs, are manufactured in low volumes,
and are made using expensive tooling. Here we investigate the potential of replacing these
injection-molded positives with plastic patterns created using stereolithography. By using 3D
printing instead of injection molding to create the positives, we can dramatically reduce tooling
costs and leverage the freedom of design offered by 3D printing to create more intricate turbine
blade designs. While using 3D printed positives to create molds for shape castings was one of the
earliest examples of rapid prototyping of metallic components, the present work highlights the
potential of extending this approach to molds used for growing single crystal parts.",,,,,,
"['Palmer, J. A.', 'Davis, D. W.', 'Gallegos, P. L.', 'Yang, P.', 'Chavez, B. D.', 'Medina, F. R.', 'Wicker, R. B.']",2020-02-24T15:37:09Z,2020-02-24T15:37:09Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80084', 'http://dx.doi.org/10.26153/tsw/7105']",eng,2005 International Solid Freeform Fabrication Symposium,Open,stereolithography,Stereolithography: A Basis for Integrated Meso Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c32b5325-929d-49a0-a40f-ed6a99036a7b/download,,,,,,,,
"['Bzymek, Zbigniew M', 'Theis, Scott', 'Manzur, Tariq', 'Roychaudhuri, Chandra', 'Sun, Lianchao', 'L. Shaw, Leon']",2019-02-20T17:47:25Z,2019-02-20T17:47:25Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73458', 'http://dx.doi.org/10.26153/tsw/610']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD']",Stereometric Design for Desk-Top SFF Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1deafcfc-b2a3-427e-8f2f-a5dcb92ce88e/download,,"Solid Freeform Fabrication (SFF) technologies refer to the fabrication of physical parts directly from
computer based solid models described by STL (Stereo Lithography) or VRML (Virtual Reality Modeling
Language) files generated by Computer-Aided Design (CAD) systems. Most of the SFF processes produce parts
by building them layer by layer using a row by row pattern, though it is possible to build the part using other
patterns. The SFF technology represents a challenge to designers who, in addition to making decisions
concerning optimum shape and functionality of the entire part, have'to take under consideration several other
manufacturing factors. These factors cover a wide range of technical issues such as Computer-Aided Design
model generation, part description and model slicing files, laser path files, precision of part design, rendering
patterns, manufacturing tolerances, thermal expansion and residual stress phenomena.
This paper investigates the effect of rendering patterns on the integrity, material characteristics and
mechanical properties of the parts prepared by a desk-top SFF device using diode lasers. Fe - Bronze (Cu - Sn)
premixed metal powders were used as the starting material. The particle size was about 100 /lm to 200 /lm.
Density, tensile strength and microstructure of the parts prepared using different rendering patterns were
characterized. The results were analyzed to seek optimal rendering patterns. It was noticed that the samples
were strong along the laser scanning direction, while they were weak perpendicular to the scanning direction.
These results suggest that the laser scanning patterns should be designed to minimize the warping and maximize
the strength of the part in the direction depending on the part's function.",,,,,,
"['Allanic, A.L.', 'Medard, C.', 'Schaeffer, P.']",2018-04-19T18:27:36Z,2018-04-19T18:27:36Z,1992,Mechanical Engineering,doi:10.15781/T27D2QQ9K,http://hdl.handle.net/2152/64407,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['Laser 3D', 'SPL', 'SS', 'SPL machines', 'CAD designs']",Stereophotolithography: A Brand New Machinery,Conference paper,https://repositories.lib.utexas.edu//bitstreams/210593b2-96ad-4f37-872a-869486e10ee2/download,,,,,,,,
"['Perez, Mireya', 'Block, Michael', 'Espalin, David', 'Winker, Rob', 'Hoppe, Terry', 'Medina, Francisco', 'Wicker, Ryan']",2021-10-05T19:07:15Z,2021-10-05T19:07:15Z,8/15/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88411', 'http://dx.doi.org/10.26153/tsw/15350']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'medical devices', 'medical sterilization']",Sterilization of FDM-Manufactured Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0962f07d-a261-4a4e-96a3-c16d74916845/download,University of Texas at Austin,"Fused Deposition Modeling (FDM) can be used to produce an array of medical devices;
however, for such devices to be practical, they must be manufactured using sterilizable materials.
Nine FDM materials were tested using four methods of sterilization: autoclave, ethylene oxide,
hydrogen peroxide, and gamma radiation. Sterility testing was performed by incubating the
samples in Tryptic Soy Broth for 14 days. The majority of the materials were sterilizable by all
four methods while deformations were caused by autoclaving. Results from this research will
allow medical staff to sterilize an FDM-manufactured device using a suitable method.",,,,,,
"['Hiller, Jonathan D.', 'Lipson, Hod']",2021-09-28T19:40:22Z,2021-09-28T19:40:22Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88165', 'http://dx.doi.org/10.26153/tsw/15106']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['additive fabrication technology', 'Additive Manufacturing File', 'STL 2.0', 'STL file format']",STL 2.0: A Proposal for a Universal Multi-Material Additive Manufacturing File Format,Conference paper,https://repositories.lib.utexas.edu//bitstreams/157ede43-8378-4453-8b8f-ed031d6dbfd1/download,University of Texas at Austin,"The de-facto standard STL file format has served the rapid prototyping
community for over two decades, but falls short with the advent of new
technological developments such as the ability to handle multiple and graded
materials, specify volumetric digital inkjet patterns and surface colors. We study a
variety of requirements for additive fabrication technologies and propose a new
compact XML-based file format. The new Additive Manufacturing File (AMF)
format allows the resolution-independent specification of geometry and material
properties. Regions may be defined geometrically either using a triangle mesh,
using functional representations, or through a voxel bitmap. Each region is
associated with a material, which may be defined as a base (single) material or
hierarchically by a combination of other materials, either functionally (enabling
smooth gradients) or voxel-wise (for arbitrary microstructure). Files can be self-contained or refer to external or online material libraries. With a simple
conversion, the AMF file format is both forward and backwards compatible with
the current standard STL format, and the flexibility of the XML structure enables
additional features to be adopted as needed by CAD programs and future additive
manufacturing processes. Code and examples are publicly available.",,,,,,
"['Qu, Xiuzhi', 'Stucker, Brent E.']",2019-10-18T15:09:05Z,2019-10-18T15:09:05Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76233', 'http://dx.doi.org/10.26153/tsw/3322']",eng,2001 International Solid Freeform Fabrication Symposium,Open,STL-based,STL-based Finish Machining of Rapid Manufacturing Parts and Tools,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e48fd4f8-3411-4e26-991a-f60fcc2cccd1/download,,"Accuracy and surface quality problems when utilizing layered manufacturing
technologies have limited its use in tooling areas. Therefore, in some situations a CNC
machine is still necessary for finish machining of rapid manufactured parts and tools.
This paper presents a STL-based CNC machining technique for automating the finishing
of RP tools and parts to obtain CNC accuracies and surface finishes. Preprocess
operations, such as rotate and scale, are used to change the part orientation and
compensate for shrinkage in the whole process. An offset algorithm is developed to add
“skin” to the original STL file to make sure enough material is left for finish machining
after the rapid manufacturing process. The machining strategy of adaptive raster milling
of the surface, plus hole drilling and sharp edge contour machining, is proposed to finish
the RP parts and tools. Corresponding algorithms of adaptive tool path generation for
raster milling, automatic hole recognition and drilling tool path generation, and automatic
sharp edge detection and tool path generation are developed. Finally, a designed
benchmark is machined successfully by using the above mentioned machining strategies
and tool paths generated by developed software.",,,,,,
"['Johnston, Scott', 'Frame, Dustin', 'Storti, Duane', 'Anderson, Rhonda']",2020-02-12T15:33:30Z,2020-02-12T15:33:30Z,8/4/04,Mechanical Engineering,,"['https://hdl.handle.net/2152/79939', 'http://dx.doi.org/10.26153/tsw/6965']",,2004 International Solid Freeform Fabrication Symposium,Open,Strain Analysis,Strain Analysis of Initial Stage Sintering of 316L SS Three Dimensionally Printed (3DP TM) Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a85480f-0f75-4db2-a642-26b7ec1ab694/download,,,,,,,,
"['Charan, B.', 'Bagchi, A.', 'Ogale, A.A.', 'Renault, T.']",2018-05-03T19:45:16Z,2018-05-03T19:45:16Z,1993,Mechanical Engineering,doi:10.15781/T2WD3QJ7N,http://hdl.handle.net/2152/65069,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['SLA', 'ADPU', 'SFF techniques', 'CAD', '3D CAD systems']",Strategy for Composite Development in Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e1b21618-cf87-4a87-acf5-c0e9160c9b22/download,,"The polymeric parts built with a stereolithography apparatus (SIA) have good dimensional
accuracy, but they cannot be used as functional prototypes because of their low mechanical
properties. This paper describes the concept of fabricating fiber composites by 3-D
photolithography. In this process, the strength and stiffness of parts are improved over
stereolithography by adding fiber reinforcement to the resin. An automated desktop
photolithography unit (ADPU) was designed and built in-house, to add continuous E-glass or
quartzfibers in situ to the photoresin. Thefirst composite parts made by 3-Dphotolithography are
presentedin this paper, thefeasibility ofcurvilinearaddition offibers is demonstrated, andstrategies
for selective reinforcement are discussed.",,,,,,
"['Amine, Tarak A.', 'Sparks, Todd E.', 'Liou, Frank']",2021-10-04T21:11:39Z,2021-10-04T21:11:39Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88347', 'http://dx.doi.org/10.26153/tsw/15286']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'laser deposition', 'milling process']",A Strategy for Fabrication Complex Structures via a Hybrid Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/286e17eb-502d-4a5c-a52e-123545ca372a/download,University of Texas at Austin,"The purpose of this paper is to introduce a strategy for fabricating complex structures via
a hybrid manufacturing process. The Laser Aided Manufacturing Process (LAMP) lab at
Missouri S&T has developed a hybrid process combining both a direct metal deposition process
and a five-axis CNC milling. Accessibility is a difficulty when finish machining internal
features. The concept is to pause the deposition process to finish machine an internal feature
while it is still visible is one possible solution to this issue. However, this must be done in a
manner that will not be spoiled when the deposition process continues. This paper discusses
processing strategy, tool selection, and experimental validation of a technique to build complex
structures via mid-process machining with an undercutting mill.",,,,,,
"['Tran, Hong-Chuong', 'Lo, Yu-Lung', 'Le, Trong-Nhan']",2021-11-18T17:43:09Z,2021-11-18T17:43:09Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90443', 'http://dx.doi.org/10.26153/tsw/17364']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'selective laser melting', 'surrogate model']",A Strategy to Determine the Optimal Parameters for Producing High Density Part in Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ab9290f-40df-4625-88f5-00534286940a/download,University of Texas at Austin,"Finding the processing conditions which can produce high density components using Selective Laser
Melting (SLM) technique based on trial-and-error is costly and time consuming. With a given SLM machine
characteristics (e.g., laser power, scanning speed, laser spot size and laser type), powder material and powder
size distribution, the present study proposes an approach to reduce the time and cost in searching optimal
parameters for fabricating fully dense parts. The proposed method include several simulation models which are
powder bed simulation, Monte Carlo ray tracing simulation, Finite Element Heat Transfer simulation and
surrogate modeling. These simulation models are employed to find the viable processing parameters to produce
high density component. The experimental results show that the proposed methods results in a maximum
component density of 99.97%, an average component density of 99.89% and a maximum standard deviation of
0.03%.",,,,,,
"['Kolter, M.', 'Schleifenbaum, J.H.']",2024-03-27T16:07:00Z,2024-03-27T16:07:00Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124501', 'https://doi.org/10.26153/tsw/51109']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'powder bed fusion', 'PBF-LB\\M', 'streaming']",Streaming in Additive Manufacturing: Analyzing the Impact on the Powder Bed Fusion of Metals Process Chain,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d3fff8f-3928-48eb-9b15-8edd73b133c3/download,University of Texas at Austin,"Streaming is a popular concept in the music and movie industry and has helped solve problems related to
file distribution, storage capacity and intellectual property protection. In recent years, streaming has also become
a research topic for the manufacturing sector, e.g., to collect data for predictive maintenance, advanced machine
control concepts, or over-the-air updates. After initial studies have investigated the feasibility of streaming for
additive manufacturing technologies, the question how streaming will affect the process chain remains open. In
the music and movie industries, new business models and customer experiences have been created, leading to
billion-dollar businesses and the creation of companies such as Netflix and Spotify. By drawing parallels from
music and media to the AM industry this paper gives an overview of potential innovations fostered by streaming
in the domain of Additive Manufacturing (AM) such as file distribution and novel process control possibilities.
Furthermore, the impact of these innovations on the process chain is discussed by the example of Powder Bed
Fusion of Metals with Laser Beam (PBF-LB/M).",,,,,,
"['Wise, Sean', 'Bobbio, Lourdes', 'Russo, Analisa', 'Simpson, Timothy', 'Beese, Allison M.']",2023-02-17T14:51:12Z,2023-02-17T14:51:12Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117487', 'http://dx.doi.org/10.26153/tsw/44368']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Structural Electroplating', 'Metal-Clad Composites', 'Electroplated AM Plastic', 'Topology Optimized Design']","Strength Comparison of Topology Optimized Lattice from Printed SLA Resin, Electroplated Resin and PBF Aluminum Alloy",Conference paper,https://repositories.lib.utexas.edu//bitstreams/1a241942-5b58-4ebc-8a33-7b6828e2c383/download,,"Given the high cost of metal components made with powder bed fusion (PBF), we
compare the strength of two electroplated resin components against monolithic stereolithography
(SLA) polymer and BPF aluminum alloy copies of the same geometry. Using Rule of Mixtures
(ROM) analysis, validated by ASTM tensile strength measurements, two coating sequences were
designed to provide electroplated samples with half the tensile strength and approximately equal
tensile strength to PBF AlSi10Mg, respectively. All four sets were subjected to 3-point bending.
The monolithic materials had higher proportionate maximum load with respect to tensile
strength; however, the electroplated polymer parts displayed enhanced bending response relative
to their designed tensile strength. The plated resin part with weaker coating bore 85% of the load
of the PBF AlSi10Mg part while the parts with a stronger coating bore almost twice the load of
the PBF AlSi10Mg part in a 3-point bend configuration. The enhanced performance may be due
to the surface reinforcement from the high strength coating, which better resists bending and
buckling in this type of design.",,,,,,
"['Koju, Naresh', 'Yang, Li']",2024-03-27T15:58:33Z,2024-03-27T15:58:33Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124495', 'https://doi.org/10.26153/tsw/51103']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['lattice structure', 'strength enhancement', 'analytical model', 'failure propagation/pattern']",Strength Enhancement of cellular structures through selective reinforcement of elements based on analytical modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ae88c071-eb39-4165-8a3c-ac4c14ca870c/download,University of Texas at Austin,"This work investigates the strength enhancement of 2D cellular structures via individual element
thickness optimization based on the analytical model for critical elements. To focus on the
investigation of the enhancement method, a rather simplified perfectly elastic material property
was assumed, and an analytical model was utilized to identify the critical element of several
cellular structure designs. Stepwise element thickness enhancement was utilized to investigate the
effectiveness of overall strength enhancement. The results indicate that the strength of cellular
structures can be improved by selectively reinforcing critical elements. In addition, the enhanced
cellular structures also exhibit altered fracture failure characteristics that could potentially be
exploited for more application objectives.",,,,,,
"['Stewart, T D', 'Dalgarno, K W', 'Childs, T H C', 'Perkins, J']",2019-02-26T16:31:24Z,2019-02-26T16:31:24Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73482', 'http://dx.doi.org/10.26153/tsw/632']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['DTM', 'Rapid prototyping']",Strength of the DTM RapidSteel 1.0 Material,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d141adff-67a6-436a-9c2f-609cf3cd3286/download,,"This paper reports the results of a study into the strength of the DTM RapidSteel 1.0 material.
Elastic modulus and strength of the metal/copper composite material was investigated as a
function of the distance from the point of copper infiltration, the furnace cycle duration, and the
furnace type. The microstructure of the RapidSteel material was also examined in an attempt to
understand the science behind the infiltration process. The results have implications for the
design of tools to be made using the RapidTool process in situations where the tool will be used
as a production tool, rather than a prototype tool.",,,,,,
"['Yerazunis, William S.', 'Barnwell, John C. III', 'Nikovski, Daniel N.']",2021-10-28T19:09:19Z,2021-10-28T19:09:19Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89671,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['fused-filament fabrication', '5-axis additive manufacturing', 'stress tensor', 'aligned deposition paths', 'ABS', 'nylon', 'polyester', '3D printing']","Strengthening ABS, Nylon, and Polyester 3D Printed Parts by Stress Tensor Aligned Deposition Paths and Five-Axis Printing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/13b5ddde-c504-44d9-984a-1291c96ac902/download,University of Texas at Austin,,,"This paper discusses the design, build, and testing a 5-axis FFF manufacturing system that accepts a CAD model, performs a finite-element model of the part as stresses in use, and for a subset of possible parts, aligns laydown paths in five dimensions (XYZ, tip, and tilt) with the in-use stress tensor; the aligned paths are then converted to 5-axis G-code and printed on our 5-axis additive manufacturing (5AAM) printer.",,,,
"['Ghayoor, Milad', 'Mirzababaei, Saereh', 'Lee, Kijoon', 'He, Yujuan', 'Chang, Chih-hung', 'Paul, Brian K.', 'Pasebani, Somayeh']",2021-11-18T02:17:49Z,2021-11-18T02:17:49Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90411', 'http://dx.doi.org/10.26153/tsw/17332']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'nanocomposite', 'oxide dispersion strengthened alloy', '304L stainless steel']",Strengthening of 304L Stainless Steel by Addition of Yttrium Oxide and Grain Refinement during Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4670adb7-bee4-41a5-bff3-663cadc586ef/download,University of Texas at Austin,"This study investigates the role of submicron yttrium oxide on the microstructural evolution
and mechanical properties of selective laser melted 304L oxide dispersion strengthening (ODS)
nanocomposite. 304L SS powder and a mixture of 304L SS powder and yttria nanoparticles were
used as two feedstocks for fabricating parts using selective laser melting (SLM) process. Scanning
electron microscopy and energy-dispersive X-ray spectroscopy revealed a homogenous
distribution of Si-Mn-O nanoparticles in the SLM 304L matrix and Y-Si-O nanoparticles in the
SLM 304L ODS alloy. Electron backscatter diffraction images imply that the addition of yttria
disrupts the formation of large columnar grains in SLM 304L, resulting in the formation of finer
equiaxed grains. The average microhardness values increased from 240 HV in SLM 304L to 305
HV in SLM 304L ODS alloy, due to the combined effects of grain refinement and dispersion
hardening.",,,,,,
"['Katz, A.', 'Nussbaum, J.', 'Crane, N.B.', 'Lusk, C.P.']",2021-10-13T21:42:17Z,2021-10-13T21:42:17Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88790', 'http://dx.doi.org/10.26153/tsw/15724']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Bernoulli-Euler hypothesis', 'stress-limiting test', 'strength limits', 'test structures', 'additive manufacturing']",Stress-Limiting Test Structures for Rapid Low-Cost Strength Assessment,Conference paper,https://repositories.lib.utexas.edu//bitstreams/260d39ee-8cf9-41ae-9f99-660c22b5bb69/download,University of Texas at Austin,"This project designed and manufactured a planar structure, which under force undergoes a defined
displacement. The structure has a series of thin members which bend around circular cams of
different radii. The Bernoulli-Euler hypothesis states that the moment and hence the stresses are
proportional to the curvature. Thus the varying size of the cams puts varying strains on the
members. The cam which causes the members to fail indicates the strength of the material.
Successfully completing a displacement demonstrates a minimum strain capability of the sample.
A series of test coupons can be used to find the strength limits of the printed components without
requiring expensive testing equipment. The vibration frequency of the test structure also provides
a measure of the part stiffness and can provide a non-destructive measurement of process
consistency. This approach could be a useful process characterization/monitoring method for
additive manufacturing systems. This planar structure was used to investigate variations between
thermal extrusion parts on the same machine and between different machines.",,,,,,
"['Hague, Richard', 'Dickens, Phill']",2018-11-02T14:53:38Z,2018-11-02T14:53:38Z,1995,Mechanical Engineering,doi:10.15781/T2DZ03M55,http://hdl.handle.net/2152/69331,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['stereolithography models', 'Quickcast', 'thermoset plastic material']",Stresses Created in Ceramic Shells Using Quickcast Models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a8d23223-5d7a-4b7a-9916-d725b5074306/download,,"Improvements in resins and build styles, coupled with increasing experience, have meant that
ever more metal parts are being produced from stereolithography (SL) models via the investment
casting route. However, despite these advances, it is still not possible for every foundry to directly
use SL models as thermally expendable patterns and gain the same success as achieved with wax
patterns.
The central reason behind the inability to investment cast some SL parts' lies in the expansion
ofthe cured resin. The thermoset plastic material ofthe SL model does not melt during the autoclave
process and its expansion creates stresses in the ceramic wall that cause the relatively weak shell to
crack.
A work programme is in progress at the University ofNottingham to show how, why and
when these stresses are built up and compare them to the stresses created during the conventional
autoclaving ofwax parts. The eventual aim ofthe project is to gain a full understanding ofthe stresses
induced in the models and to develop new build structures that will allow the successful autoclaving
and subsequent casting ofstereolithography models.
Details ofthe work programme are outlined in this paper, along with initial results obtained.",,,,,,
"['Yoo, J.', 'Cima, M.J.', 'Khanuja, S.', 'Sachs, E.M.']",2018-05-03T16:35:56Z,2018-05-03T16:35:56Z,1993,Mechanical Engineering,doi:10.15781/T28S4K62P,http://hdl.handle.net/2152/65035,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Departments of Materials Science and Engineering and Mechanical Engineering', 'Three Dimensional Printing', 'CAD representation', '3DP']",Structural Ceramic Components by 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d04a5e9c-a8ae-4ab4-9262-e7814aed6380/download,,"The Three Dimensional Printing (3DP) Process hasbe~nadapted for processing of fine
ceramic powders to •• prepare structllraLceramic components. Our preliminary study was
designed to reveal those aspects ofthe.3DPprocesswhichmust be modified for use with
fine ceramic powders. The basic elements of the modified process are to spread
submicron alumina powder and printJatex binder. Several methods were used to spread
thin layers of submicron powders. Gre.enparts are isostaticaUypressed followed by
thermal decomposition prior to sintering to remove the polymer. The fired alumina
components are greater than 99.2% dense and have·average flexural strength of324 MPa.
This is lower than the best conventionally prepared alumina, but we believe that the
strength results will improve as we learn more about the relationship between strength
limiting flaws and the 3DP build process.",,,,,,
"['Cima, M.J.', 'Yoo, J.', 'Khanuja, S.', 'Rynerson, M.', 'Nammour, D.', 'Giritlioglu, B.', 'Grau, J.', 'Sachs, E.M.']",2018-11-08T16:04:06Z,2018-11-08T16:04:06Z,1995,Mechanical Engineering,doi:10.15781/T2T43JN7J,http://hdl.handle.net/2152/69896,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['3DP', 'initial density', 'defect-free layers']",Structural Ceramic Components by 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3377273a-bd1e-4a0f-8e7a-bb19d9105288/download,,"Several technical challenges exist in adapting Three Dimensional Printing (3DP) to processing of dense ceramic structures. The sintering rate of particulate bodies depends on the sintering mechanism, average powder size, and initial packing density. Fine powders are necessary to ensure appreciable densification rates from powders which sinter by solid state transport. A critical packing density exists for such powders below which densification does not occur. Special build strategies are, therefore, required for 3DP of ceramic structures. We have successfully demonstrated five approaches to produce dense ceramic components by 3DP. First, spray-dried granules of fine ceramic powders are spread in the existing 3DP equipment and bound using a latex binder through an ink-jet print head. The resulting components are then isostatically pressed to raise the green density to a point that the parts will fully densify when fired. A second approach uses glass powders that sinter by a viscous sintering mechanism. Such bodies sinter to full density at all initial green densities. Spray-dried granules of fine glass powders are spread and bound with latex followed by directly sintering to full density. Both of these approaches produce rather large linear shrinkage because of the low overall packing density. Large glass particles have a much higher packing density and produce bodies that sinter to full density because of the rapid viscous sintering. This third technique produces fully dense parts with linear shrinkage of about 15%. The fourth approach involves glass infiltration of porous ceramic bodies. Our results indicate that this technique can produce dense parts with less than 1% linear shrinkage. Finally, the 3DP process has been modified to permit deposition of fine powders as slurries, rather than dry powders. The resulting process considerably increases the bed density and the resulting fine ceramic parts can be sintered to full density without intermediate isopressing.",,,,,,
"['Agarwala, M.K.', 'Weeren, R. Van', 'Vaidyanathan, R.', 'Bandyopadhyay, A.', 'Carrasquillo, G.', 'Jamalabad, V.', 'Langrana, N.', 'Safari, A.', 'Garofalini, S.H.', 'Danforth, S.C.', 'Burlew, J.', 'Donaldson, R.', 'Whalen, P.', 'Ballard, C.']",2018-10-03T19:13:14Z,2018-10-03T19:13:14Z,1995,Mechanical Engineering,doi:10.15781/T2N873J4Q,http://hdl.handle.net/2152/68680,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Solid free-form fabrication', 'CAD', 'polymer/wax based binder systems']",Structural Ceramics by Fused Deposition of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/617b8fd4-e9c5-495e-a218-afeaa0919ecb/download,,"Fused Deposition of Ceramics (FDC) is a SFF technique, based on FDMTM technology, for
fabrication of advanced structural ceramics from powderlbinder filaments. In this study, in-situ
reinforced (ISR) Si3N4 powder and polymer/wax based binder systems were used as filament
material for FDC processing using a commercially available FDMTM system, 3D Modeler.
Powderlbinder feedstocks were mixed using a torque rheometer and filaments were fabricated
using a capillary rheometer and twin screw extruder. Green FDC components were built from
these filaments and then characterized for inter-road and inter-layer bonding. Binder removal
procedures were established for FDC green components to yield brown parts without distortion or
shape change. Brown FDC parts were characterized for carbon residue, pore distribution and
dimensional changes. Brown FDC parts were then sintered and the sintered density,
microstructure, and shrinkage anisotropy were studied.",,,,,,
"['Klosterman, Donald A', 'Chartoff, Richard P.', 'Priore, Brian', 'Osborne, Nora', 'Graves, George', 'Lightman, Allan', 'Pak, Sung S.', 'Weaver, Jerry']",2018-11-09T16:08:26Z,2018-11-09T16:08:26Z,1996,Mechanical Engineering,doi:10.15781/T2FQ9QR1S,http://hdl.handle.net/2152/69927,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'CAD', 'Rapid prototyping']",Structural Composites Via Laminated Object Manufacturing (LOM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/bdd1fe03-2df1-4f71-875c-4e813f69a70f/download,,"An innovative, rapid prototyping (RP) technology is being adapted for the automated
manufacture of composite tools and molds. The technology is a direct extension ofthe
Laminated Object Manufacturing (LaM) process. LaM is an established technique that is used
to create solid prototypes by sequentially cutting and laminating layers of adhesive paper. With
this process a full scale, geometrically complex prototype can be created directly from a CAD
image in less than a day. This report provides a description ofhow LaM is being applied for the
production offunctional composite laminates, such as composite tools and molds. Several
material systems have been examined, including monolithic ceramics (SiC), ceramic matrix
composites (SiC/SiC), and polymer matrix composites (glass/epoxy). Realistic tools and molds
are being created from these materials using the LaM process with little modification. However,
post processing (ceramic densification, polymer post cure) is necessary to obtain articles with
good mechanical properties. Technical solutions are being developed for maintaining
geometrical accuracy during the post processing cycles. The mechanical properties and
performance ofthe LaM-produced parts are reported herein. Overall, this technology holds
great promise for lowering the cost oftooling due to the ability to create geometrically complex
objects rapidly using a highly automated processing sequence.",,,,,,
"['Johanson, Roy', 'Kikuchi, Noboru', 'Papalambros, Panos']",2018-10-03T16:01:19Z,2018-10-03T16:01:19Z,1994,Mechanical Engineering,doi:10.15781/T2MG7GF2Q,http://hdl.handle.net/2152/68657,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['structural optimization', 'layered structures', 'generalized topology optimization']",Structural Design for Freeform Fabrication using Composite Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/31081296-ac3a-422d-82ca-b1ed74b3694f/download,,"Advances in the development of methods to Perform topology optimization offer the
ability to design novel structures composed of dense composite materials. These
structures, which possess superior mechanical proPerties, can only be produced through
the use of layered manufacturing techniques. In this paper, we demonstrate a technique for
the design of layered structures composed of composite materials. In addition, this
procedure allows the design of the composite materials used for fabrication of such
components on a microstructural level.",,,,,,
"['Smith, Tyler', 'Failla, Jordan', 'Lindahl, John', 'Kim, Seokpum', 'Hassen, Ahmed Arabi', 'Duty, Chad', 'Joshi, Pooran', 'Stevens, Christopher', 'Kunc, Vlastimil']",2021-11-15T22:26:06Z,2021-11-15T22:26:06Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90294', 'http://dx.doi.org/10.26153/tsw/17215']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['printing monitoring', 'internal failures', '3D printed structures', 'health monitoring', '3D printing']",Structural Health Monitoring of 3D Printed Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d02d2e1f-a82f-4c5e-a7e5-92ae59a5d7bf/download,University of Texas at Austin,"3D printed parts are used in industry for both tooling application and smaller parts in
assembled structures. Articles made through polymer based additive manufacturing are anisotropic
and may have defects throughout the part. For instance, the layer to layer interactions are weaker
than the in-plane printing which can cause delamination of the layers. Identifying when and where
the cracks form can be very difficult if the cracks are inside the structure This paper introduces an
innovative patent-pending method to monitor polymer-based 3D printed structures for internal
failures by printing a highly sensitive conductive material into the part itself. When a section of
the conductive material inside the part is damaged or split, the resistance across the conductive
pathway increases which will indicate that the article has been damaged. We present several small
printed circuits and observations that show as a crack is introduced to the structure, the resistance
measured increases which alerts users that a crack has formed/propagated.",,,,,,
"['Siggard, Erik J.', 'Madhusoodanan, Anand S.', 'Stucker, Brent', 'Eames, Brandon']",2020-02-27T19:46:52Z,2020-02-27T19:46:52Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80097', 'http://dx.doi.org/10.26153/tsw/7118']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic Consolidation,Structurally Embedded Electrical Systems Using Ultrasonic Consolidation (UC),Conference paper,https://repositories.lib.utexas.edu//bitstreams/ec7e9d21-e42f-4d4b-ab09-2befb45d60f8/download,,"Current research has demonstrated the use of Ultrasonic Consolidation (UC) to embed
several USB-based sensors into aluminum, and is working toward embedding suites of
sensors, heaters and other devices, connected via USB hubs, which can be monitored and
controlled using an embedded USB capable processor. Additionally, the research has
shown that electronics can be embedded at room temperature, but with some inter-layer
delamination between the ultrasonically bonded aluminum layers. Embedding sensors
and electronics at 300o
F to overcome the delamination issues resulted in optimal
bonding, and the sensors used thus far have functioned normally. Future investigation
will explore other UC parameter combinations to ascertain the quality of embedding at
lower temperatures.",,,,,,
"['Khurana, Jivtesh B.', 'Simpson, Timothy W.', 'Frecker, Mary']",2021-11-16T15:26:51Z,2021-11-16T15:26:51Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90313', 'http://dx.doi.org/10.26153/tsw/17234']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['active-z printing', 'layer generation', '3D layers', 'material extrusion additive manufacturing']",Structurally Intelligent 3D Layer Generation for Active-Z Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c2ac32e-86be-4477-bdef-dc496a3fa5e9/download,University of Texas at Austin,"Active-Z Printing offers the ability to deposit material along non-planar layers to control
the mechanical behavior of parts produced by material extrusion additive manufacturing. These
non-planar layers can be exploited to incorporate a part’s loading conditions into the slicing
process by aligning deposited layers with predicted localized stress tensors. In this work, we
demonstrate that superior structural performance can be achieved by taking advantage of layer
shapes derived from principal stress trajectories. A slicing method incorporating stress field data
is developed to generate 3D layers from principal stress trajectories. As a demonstration, a 3-point
bend specimen is manufactured with 3D layers derived from principal stress trajectories developed
in a deformed specimen. Mechanical tests are conducted and 3-point bend specimens are shown
to have superior mechanical response. This novel approach introduces new capabilities to Additive
Manufacturing for structurally intelligent fabrication.",,,,,,
"['Jayanthi, Suresh', 'Keefe, Michael', 'Gargiulo, Edward P.']",2018-10-03T15:44:22Z,2018-10-03T15:44:22Z,1994,Mechanical Engineering,doi:10.15781/T2862BW9H,http://hdl.handle.net/2152/68652,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['stereolithography', 'photopolymer models', 'laser scanning']",Studies in Stereolithography : Influence of Process Parameters on Curl Distortion in Photopolymer Models,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a274c618-617c-4c2f-9b97-d89361e4c269/download,,"To make the stereolithography process more useful in the manufacturing
industry, the dimensional accuracy of the parts it creates
should be very high. But due to the nature of the polymerization
process and the mechanism of laser scanning, distortions are induced
in the parts. Curl distortion is a major source of inaccuracy in this
photopolymer based technology. This paper approaches the problem
from a process related point of view by addressing the major parameters
reponsible for curl.The work presented here is a continuation of
a similar work presented at the SFF symposium in 1993 [1].",,,,,,
"['Wang, Jiwen', 'Li, Xiaoxuan', 'Shaw, Leon L.', 'Marcus, Harris L.', 'Cameron, T.B.', 'Kennedy, C.']",2019-10-22T18:05:31Z,2019-10-22T18:05:31Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76329', 'http://dx.doi.org/10.26153/tsw/3418']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Restoration,Studies on Slurry Extrusion for Dental Restoration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc0fdedd-02dd-451a-bb19-e40d78d34300/download,,"This study investigates dental restoration via dental powder delivery by slurry extrusion,
followed by laser densification of these extruded slurries. The entire process is fully controlled
by a computer. The shape of the extrudate before laser densification depends strongly on the
formulation of slurries. Slurries prepared in a stable pH range can disperse high volume of solids,
but have low viscosities and spread uncontrollably when extruded. In contrast, slurries first
prepared in a stable pH range and subsequently adjusted to an unstable pH range have exhibited
pseudoplastic behavior. Such slurries have a low extrusion pressure to avoid phase separation,
and at the same time their yield points are high enough to maintain the shape of extrudates.","The authors gratefully acknowledge financial support provided by
the National Science Foundation under Grant No: DMI-9908249.",,,,,
"['Belchou, Alexander P.', 'Jacob, Ashish', 'Joshi, Sanjay', 'Reutzel, E.W.', 'Coutts, Peter']",2023-02-10T13:56:06Z,2023-02-10T13:56:06Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117447', 'http://dx.doi.org/10.26153/tsw/44328']",eng,2022 International Solid Freeform Fabrication Symposium,Open,SS316L,Studies on Thin and Thick-Walled SS316L Overhanging Specimens Manufactured Using Powder-Fed Laser-Based  Directed Energy,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7d3722f1-5109-4f2c-8f48-0a1be4ac4f40/download,,"Effective Design for Additive Manufacturing (DfAM) requires accurate knowledge of a 
machine’s capabilities and limitations. One important factor is the machine’s ability to deposit 
unsupported overhanging features. A general method was devised to characterize the ability of a 
powder-fed Laser-Based Directed Energy Deposition (LB-DED) system to deposit overhanging 
features with various overhang angles, wall thicknesses, and scan strategies, which was then 
investigated on a DMG Mori LASERTEC 65 3D Hybrid LB-DED system using 3-axis toolpaths. 
To assess the accuracy of the manufactured overhang angle, for each specimen the angle of the 
downward facing surface and upward facing surface were measured and compared to the target 
overhang angle. It was observed that for the longitudinal scan strategy, overhang accuracy 
substantially degraded as wall thickness increased. For the transverse and cross hatch patterns 
there is no observable trend between the achievable overhang angle and the wall thickness. In 
addition, it was observed that in general increasing the target overhang angle degrades the 
accuracy of the manufactured overhang angle. The most accurate overhang angles overall were 
achieved for the longitudinal 1 bead thick specimens. These results will help inform future 
DfAM and path planning strategies. This research fills a gap in the literature by providing a 
general method to assess overhang capabilities for LB-DED systems.",,,,,,
"Yang, L.",2021-11-01T21:39:42Z,2021-11-01T21:39:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89763,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['cellular structures', 'size effects', 'simulation']",A Study About Size Effects of 3D Periodic Cellular Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0975d2db-2b49-4ad3-a738-48fe6d08885e/download,University of Texas at Austin,"In the design of unit cell based cellular structures, idealized boundary conditions are often
assumed to simplify analysis. However, such treatments also result in various deviations
from reality. In this study, both lateral and along-the-stress size effects s of multiple cellular
structural designs under compressive stress with constrained boundary motion were
investigated using simulations. It was found that different unit cell designs exhibit
significantly different size effects, which might be affected by the unit cell dimensional
aspect ratio, the unit cell Poisson’s ratios and the unit cell orientations. This study provides
a glimpse into the design considerations associated with such phenomenon.",,,,,,
"['Philo, A.M.', 'Sutcliffe, C.J.', 'Sillars, S.', 'Sienz, J.', 'Brown, S.G.R.', 'Lavery, N.P.']",2021-11-03T21:33:54Z,2021-11-03T21:33:54Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89938,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['gas flow', 'inlet design', 'Renishaw AM250', 'metal powder bed fusion', 'laser powder bed fusion', 'Hot Wire Anemometer']",A Study into the Effects of Gas Flow Inlet Design of the Renishaw AM250 Laser Powder Bed Fusion Machine Using Computational Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4902de0a-0beb-44ad-bcf1-8f19a99ab085/download,University of Texas at Austin,"Previous work has highlighted the importance of the gas flow system in laser powder
bed fusion (L-PBF) processes. Inhomogeneous gas flow experienced at the surface of the
powder bed can cause variations in mechanical properties over a build platform, where
insufficient removal of by-products which cause laser attenuation and redisposition of byproducts are believed to contribute to these variations. The current study analyses the gas flow
experienced over a build platform in a Renishaw AM250 metal powder bed fusion machine via
Hot Wire Anemometer (HWA) testing. Velocity profiles of the flow directly above the powderbed and through the centre plane normal to the inlets have been categorized. These HWA results
illustrate the inhomogeneity of the gas flow experienced over the build platform and from
literature imply that there will be insufficient removal of by-products and hence variable build
quality in specific areas of the build platform.
A Computational Fluid Dynamics (CFD) model was created in ANSYS Fluent and
validated against HWA results coupled with a Discrete Phase Model (DPM) representing the
expulsion of spatter. Velocity contours of simulated against experimental are compared, where
the results appear in good agreement.
The multiphase CFD model was then used to explore the effects of changing inlet design
parameters using a Design of Experiments (DOE) study based on an Optimal Space Filling
(OSF) method. This was to understand the effect of design parameters on flow uniformity, local
gas velocity over the processing area and spatter particulate accumulation within the build
chamber. The initial design study found that flow uniformity could potentially be increased by
21.05% and spatter accumulation on the processing area could be reduced by 26.64%. In
addition, this has given insight into important design considerations for future generation of LPBF machines.",,,,,,
"['Liu, Qingbin', 'Leu, Ming C.']",2020-02-17T14:47:22Z,2020-02-17T14:47:22Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80000', 'http://dx.doi.org/10.26153/tsw/7025']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Freeze Cast Process,Study of Ceramic Slurries for Investment Casting with Ice Patterns,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0ec7d73b-5c84-4fbd-97f8-140f3a65bdcc/download,,"Ice patterns generated by rapid freeze prototyping or a molding process can be used to
make ceramic investment molds for metal castings. Due to the use of ice, the ceramic slurries
must be poured around the pattern and cured at sub-freezing temperatures. Success of this
process depends greatly on the mold strength after the gelation of the slurries. This paper
describes the experimental results of the mold strength after the gelation of the slurries under
different compositions. The parameters considered include mixing time, alumino-silicate vs.
fused silica ratio, volume of binder, and volume of catalyst. The strength of the gelled slurries is
examined by breaking test bars on a four-point bending apparatus. Weibull modulus for each
trial is calculated based on the breaking strength from four-point bend tests. Analysis of variance
for breaking strength and Weibull analysis is performed to evaluate the significance of the effect
of each parameter. The casting of a bolt is used to demonstrate that metal castings of complex
geometry can be fabricated using investment casting with ice patterns.",,,,,,
"['Medrano, V.A.', 'Caballero, K.', 'Arrieta, E.', 'Benedict, M.', 'Wicker, R. B.', 'Medina, F.']",2023-03-29T16:37:25Z,2023-03-29T16:37:25Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117684', 'http://dx.doi.org/10.26153/tsw/44563']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'LPBF', 'F357', 'aging', 'aluminum']",Study of Different Aging Conditions for Analysis of Microstructure and Mechanical Properties of F357 Alloy Fabricated in LPBF Printer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5fcd7317-5ef7-4781-9d5a-91e72fb4f484/download,,"Aluminum F357 is a widely used material for casting in aerospace and additive manufacturing 
industry. Heat treatments are commonly applied to some aluminum alloys to modify its 
properties. With a further study on the aging and performance of the F357 with 3D printing 
technology, several industries benefit of this, military, automotive and aerospace are some 
examples, because the numerous components casted in service. This work presents mechanical 
properties of F357 specimens fabricated with EOS technology and subjected to heat treatments. 
Heat treatments conditions were applied to tensile specimens and tested. Furthermore, the 
specimens were subjected to artificial thermal aging for 100 h and 1000 h at two different 
temperatures (285 ºF and 350 ºF), and their mechanical properties were also determined. Finally, 
remarks on the comparison between the heat treatments and the effect of thermal aging on the 
microstructures and mechanical properties of the specimens will be presented.",,,,,,
"['Hopkinson, Neil', 'Dickens, Phil']",2019-02-19T16:57:06Z,2019-02-19T16:57:06Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73430', 'http://dx.doi.org/10.26153/tsw/582']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'SL process']",Study of Ejection Forces In The AIM™ Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7716edb8-1b01-4fe9-b5c7-38edbb680193/download,,"The AIM™processhas been used to successfully produce short runs ofinjection
moulded parts. One ofthe main drawbacks ofthe process is the tendency ofthe tools
to be damaged during part ejection1
.
At De Montfort University a successful AIMTM moulding cycle has been developed in
which simple shapes from polypropylene are produced and the ejection forces required
are measured. TWQ different ejection methods are used; one uses conventional ejector
pins andthe other uses a conformal ejector pad. The tool surface roughness is
measured before and after moulding to observe any changes caused by ejection.
Results show that ejector pins require a lower ejection forcethan a conformal ejector
pad and this may contribute to longer tool life forthe AIM™process. Possible
reasonsfor the results are discussed along with recommendations for further work.",,,,,,
"['Dutson, Alan J.', 'Wood, Kristin L.', 'Beaman, Joseph J.', 'Crawford, Richard H.', 'Bourell, Daniel L.']",2019-10-18T15:06:30Z,2019-10-18T15:06:30Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76232', 'http://dx.doi.org/10.26153/tsw/3321']",eng,2001 International Solid Freeform Fabrication Symposium,Open,SFF Parts,A Study of Functional Testing with SFF Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e03b62c-4fd4-4a4e-8263-3c27d0cba025/download,,"A study of functional testing with SFF parts is presented. The study includes the use of
traditional similitude methods as well as advanced similitude methods for predicting product
performance through prototype testing. Cantilever beams created from the selective laser
sintering process are used to predict the static deflection of both aluminum and polycarbonate
beams. The results of 20 experiments using various geometric, loading, and material
configurations are presented. Results of the study suggest that a coupling between geometry and
material properties exists in SLS parts. Possible sources for the coupling are discussed. An
approach for establishing the functional relationship between material and geometry is outlined.",,,,,,
"['Baich, Liseli', 'Manogharan, Guha']",2021-10-19T18:44:27Z,2021-10-19T18:44:27Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89321,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'material extrusion', 'fused deposition modeling', 'mechanical strength', 'infill print parameters and cost analysis']",Study of Infill Print Parameters on Mechanical Strength and Production Cost-Time of 3D Printed ABS Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/adddca87-4b50-4e42-b985-1733e84b7958/download,University of Texas at Austin,"The ever-growing adoption of Additive Manufacturing (AM) can be attributed to lowering
prices of entry-level extrusion-based 3D Printers. It has enabled using AM for mainstream DIY,
STEM education, prototypes and often, to produce custom complex commercial products. With
the growing number of available printers and newer materials, the influence of print parameters
specifically infill patterns on the mechanical strength and print costs need to be investigated. This
study presents the correlation of infill pattern selection and several mechanical properties along
with final part cost and production time. Infill with varying design parameters are analyzed with
respect to mechanical properties determined using ASTM standards, fabrication cost and time.
Relevant applications are presented for all the varied infill designs. Findings from this study will
help formulate criteria for relevant economically sound infill design pattern for real world
applications.",,,,,,
"['Chiu, Y.Y.', 'Liao, Y.S.', 'Hou, C.C.']",2019-10-24T18:35:33Z,2019-10-24T18:35:33Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77424', 'http://dx.doi.org/10.26153/tsw/4513']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Object Manufacturing,The Study of On-Line Waste Material Removal Procedures for Bridge Laminated Object Manufacturing (LOM) Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a9f839f-7a54-4063-b995-8852726d0f19/download,,"Focusing on the drawbacks inhered in the laminated object manufacturing (LOM), a
new Bridge-LOM process and its associated building algorithm are proposed in this
paper. The proposed Bridge-LOM process starts with the construction of the bridge
structures to link a stack of 2-D geometry contours to the outer frame based on the
proposed bridge building algorithm. Afterwards, laser is directed to cut along the
contours, and then the upper pressing head is pushed down and the layers are bonded.
This is followed by spraying some adhesive on the top of bonded layers. The
procedures of cutting, bonding and adhesive spraying are repeated until the complete
3D part is produced. From the experiments, it is verified that the proposed
Bridge-LOM process not only saves laser-cutting time, the time on waste material
removal is also reduced significantly by more than 80%. Furthermore, the hollow
bottle can even be fabricated.",,,,,,
"['Shrestha, Subin', 'Starr, Thomas', 'Chou, Kevin']",2021-11-18T00:24:01Z,2021-11-18T00:24:01Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90369', 'http://dx.doi.org/10.26153/tsw/17290']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['computed tomography', 'porosity', 'selective laser melting']",A Study of Pore Formation During Single Layer and Multiple Layer Build by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d254c557-d98c-4a15-8361-bd6747698a6d/download,University of Texas at Austin,"n this study, different hatch spacings were used to fabricate single layer and multiple layers, and
its effect on porosity was investigated by using microcomputed tomography. The combination of
laser power (100 W, 150 W, 175 W, and 195W) and scan speeds (600 mm/s, 800 mm/s, 1000
mm/s and 1200 mm/s) which resulted in the least number of pores were selected from the
previous single-track experiment. Six levels of hatch spacings were selected based on the track
width to form single and multiple layers: 60%, 70%, 80%, 90%, 120% and 150% of track
widths. For the multilayer build, the variation in keyhole porosity within the given window of
parameters were found to be attributed to the variation in the hatch spacing. In general, the pore
number decreased with increase in hatch spacing from 60% to 90% but increased when hatch
spacing further increased from 90% to 120%.",,,,,,
"['Ruprecht, John', 'Agarwal, Kuldeep']",2021-12-06T21:34:25Z,2021-12-06T21:34:25Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90679', 'http://dx.doi.org/10.26153/tsw/17598']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['printing parameters', 'biocomposites', 'cobalt chrome', 'tricalcium phosphate', 'binder jetting based additive manufacturinng']",Study of Printing Parameters in Binder Jet Additive Manufacturing of Cobalt Chrome - Tricalcium Phosphate Biocomposite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e801e5e0-3a5e-4def-b552-1c6e04f6188a/download,University of Texas at Austin,"Traditional metals such as stainless steel, titanium and cobalt chrome are used in
biomedical applications (implants, scaffolds etc.) but suffer from issues such as osseointegration
and compatibility with existing bone. One way to improve traditional biomaterials is to incorporate
ceramics with these metals so that their mechanical properties can be similar to cortical bones.
Tricalcium phosphate is such a ceramic with properties so that it can be used in human body. This
research explores the use of binder jetting based additive manufacturing process to create a novel
biocomposite made of cobalt chrome and tricalcium phosphate. Experiments were conducted and
processing parameters were varied to study their effect on the printing of this biocomposite. Layer
thickness, binder saturation and drying time affected the surface finish, dimensional tolerance and
the density of the green samples. This effect is important to understand so that the material can be
optimized for use in specific applications.",,,,,,
"['Chivate, Aditya', 'Guo, Zipeng', 'Zhou, Chi']",2023-01-20T13:58:20Z,2023-01-20T13:58:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117254', 'http://dx.doi.org/10.26153/tsw/44135']",spa,2022 International Solid Freeform Fabrication Symposium,Open,"['Proximity effects', 'oxygen inhibition', 'cross-talk', 'stereolithography']",Study of Proximity Effect in Projection-Based Micro Stereolithography Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/21b140b7-2bf3-43e0-bf6b-eaefbe99aecf/download,,"Micro Projection-based stereolithography (PSL) is a powerful technique that has the 
potential to disrupt microfabrication. However, a significant challenge that plagues µPSL is the 
local change in thresholds depending on the pitch between adjacent features, and having features 
in close spatial proximity generates undesired artifacts. This is termed as ""proximity effect,"" which 
strongly limits the attainable fabrication resolution. This can be linked to pixel-pixel light 
interactions and is found to affect the process in spatial as well as temporal domains. Despite 
tormenting researchers for a long, not much has been done to study these effects in DLP printing. 
Models developed for laser-based systems can be used to explain the proximity effect in µPSL. 
However, they still rely on hindsight observations, fail to consider the effects of large area 
projection, and fail to explain how the local change in thresholds affects the part size. This research 
uses in-situ observation systems to study the spatial and temporal proximity effects in single-shot 
PSL microfabrication. We briefly illustrate the role of oxygen in the proximity effect and lay the 
foundations to better understand the proximity effect in periodic structures with micronic inter-
feature distances.",,,,,,
"['Thomas, Baily', 'Sutton, Austin', 'Leu, Ming C.']",2021-11-02T15:06:56Z,2021-11-02T15:06:56Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89822,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['304L', 'stainless steel', 'cast iron', 'bonding', 'selective laser melting']",Study of Selective Laser Melting for Bonding of 304L Stainless Steel to Grey Cast Iron,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7b04a9a7-5162-4c71-b24b-c5135cf0700f/download,University of Texas at Austin,"While cast iron is widely used in industry, a major limitation is the weldability of a
dissimilar material onto cast iron due to hot cracking as a result of lack of ductility from graphite
flakes. Consequently, a significant amount of preheat is often employed to reduce the cooling rate
in the fusion zone, which, however, may lead to distortion of the welded parts. A potential remedy
could be the Selective Laser Melting (SLM) process, where only small melt pools are created and
thus the overall energy input is reduced. The present paper describes an investigation of the SLM
process to join 304L stainless steel with cast iron. In this study, 304L stainless steel particles
ranging from 15-45 μm in size were melted on a grey cast iron substrate by the SLM process.
Multiple sets of parameter values were chosen to test different energy densities on the tensile
strength of the bond created. Subsequent characterization of the bonded area included energy
dispersive spectroscopy (EDS) mapping for obtaining insight into the elemental diffusion, and
metallography for visualization of the microstructure. A range of energy densities was identified
for purposes of eliminating bond delamination and maximizing mechanical strength.",,,,,,
"['Ganesh-Ram, A.', 'Hanumantha, M.', 'Ravichander, B.B.', 'Farhang, B.', 'Ramachandra, S.', 'Shayesteh Moghaddam, N.', 'Amerinatanzi, A.']",2021-12-06T23:15:23Z,2021-12-06T23:15:23Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90712', 'http://dx.doi.org/10.26153/tsw/17631']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Ti-6Al-4V', 'spattering', 'anti-spatter liquid']",Study of Spatter Formation and Effect of Anti-Spatter Liquid in Laser Powder Bed Fusion Processed Ti-6Al-4V Samples,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf60ffac-beb6-4607-9bf4-ed4077ecb323/download,University of Texas at Austin,"Spatter deposition has been found to have serious effects on mechanical properties of the metal
parts printed using laser powder bed fusion technique. The spatter powder formation can cause
unfavorable changes in phases and impurity content and may result in the formation of defects in
the as-fabricated parts. This study is the first of its kind focusing on mitigation of spatter formation
through a novel technique of spraying nonflammable welding liquid during the LPBF process.
Identifying the spatter particle size distribution and dampening its formation have been the focus
of this study. Characterization of the powder spatter behaviors for Ti-6Al-4V have been made
through image processing and microstructure characterization. The findings of this study will help
in improving the mechanical properties and reducing the post-processing procedures required for
the parts processed by LPBF. This study is believed to bring a new perspective in production
planning and print quality optimization to obtain an enhanced performance from laser powder bed
fusion technique.",,,,,,
"['Zhang, Chunbo', 'Li, Leijun']",2020-03-05T18:36:35Z,2020-03-05T18:36:35Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80140', 'http://dx.doi.org/10.26153/tsw/7161']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Ultrasonic consolidation,A Study of Static and Dynamic Mechanical Behavior of the Substrate in Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7053a21e-6289-4af9-91af-d8e19577ca11/download,,"A new 2-D FEM model is developed for a fundamental study of the time
dependent mechanical behavior of the substrate in ultrasonic consolidation. The simulation
shows that for a given vibration condition, the amplitude of contact friction stress and
displacement stabilize to a saturated state after certain number of ultrasonic cycles. With
the increased substrate height, the amplitude of contact frictional stress decreases, while
that of contact interface displacement increases. The energy density and transfer coefficient
at the contact interface with different substrate heights can be used as parameters to predict
the potential for ultrasonic bonding. The reason for the decrease in the frictional stress
and displacement at the contact interface for certain substrate height seems to be caused by
the complicated wave interference occurring in the substrate. A specific substrate geometry
generates a minimum strain state at the interface as a result of wave superposition. Such
minimum strain state is believed to have produced the “lack of bonding” defect.",,,,,,
"['Dibua, Obehi G', 'Liao, Aaron', 'Tasnim, Farzana', 'Grose, Joshua', 'Behera, Dipankar', 'Foong, Chee S', 'Cullinan, Michael']",2023-01-23T14:05:41Z,2023-01-23T14:05:41Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117279', 'http://dx.doi.org/10.26153/tsw/44160']",eng,2022 International Solid Freeform Fabrication Symposium,Open,nanoparticles,A Study of the Electrical Resistivity of Sintered Copper Nanoparticles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f2415027-d636-4baa-a7c6-5c93a3465a1e/download,,"Microscale Selective Laser Sintering is a novel Additive Manufacturing process being built 
to fabricate parts with microscale resolution for applications in the microelectronics industry where 
small feature sizes are critical. This process works by sintering nanoparticles to give a better 
control on feature sizes. To get an idea of the mechanical strength of the parts fabricated with this 
process, it is important to be able to quantify the density in the manufactured parts. However, the 
parts fabricated with this process are too thin to physically handle enough to measure the density, 
but it is possible to measure the electrical resistance of these parts. So, in order to get the density 
of these parts, the relationship between electrical resistance and density has to be known. As such 
this paper presents an experimental study done on sintered copper nanoparticles to relate density 
to electrical resistance.",,,,,,
"['Liao, Y.S.', 'Li, H.C.', 'Chiu, Y.Y.']",2019-10-30T16:41:58Z,2019-10-30T16:41:58Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78190', 'http://dx.doi.org/10.26153/tsw/5279']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Object Manufacturing,Study of the Heating-and-Pressing Separation Process of Laminated Object Manufacturing (LOM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/f28d5073-a694-4afc-bc27-c023045af08f/download,,"To improve hot-pressing process currently employed by the laminated object manufacturing
(LOM), an innovated heating-and-pressing separation system is proposed, and heat transfer
problems of this system is investigated. A thermal model is first established. It is solved
numerically by the finite element method (FEM) software ANSYS, and verified by experiments.
According to the numerical solution under various operating conditions, it is suggested that if the
temperature and the moving speed of the heater are both increased, the depth of the heat affected
laminates will be reduced. The processing time will be shortened and the manufacture efficiency
will be promoted. Through analysis, it is concluded that, to obtain finished parts of high quality,
the appropriate distance between the roller and the heater can be determined.",,,,,,
"['Vrancken, B.', 'Wauthle, R.', 'Kruth, J.-P.', 'Van Humbeeck, J.']",2021-10-11T20:17:53Z,2021-10-11T20:17:53Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88625', 'http://dx.doi.org/10.26153/tsw/15559']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'residual stress', 'material properties', 'microcracking', 'surface oxidation', 'ansiotropy']",Study of the Influence of Material Properties on Residual Stress in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8b6307f8-ce47-42b8-a38c-46c5d1e055cb/download,University of Texas at Austin,"Selective laser melting (SLM) is characterized by highly localized heat input and short
interaction times, which lead to large thermal gradients. In this research, nine different materials
are processed via SLM and compared. The resulting microstructures are characterized by optical
and scanning electron microscopy. Residual stresses are measured qualitatively using a novel
deflection method and quantitatively using X-ray diffraction. Microcracking, surface oxidation
and the anisotropy of the residual stress are discussed. The different phenomena interacting with
the buildup of residual stress make it difficult to distinguish the possible correlations between
material parameters and the magnitude of residual stresses.",,,,,,
"['Cunico, Marlon Wesley Machado', 'Cunico, Miriam Machado', 'de Carvalho, Jonas']",2021-10-21T21:10:33Z,2021-10-21T21:10:33Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89450,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'smoothing process', 'dimensional evaluation']",Study of Vapourised Solvent Attack on Additive Manufacturing Part Surface,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b0e4efcc-506d-4e32-964c-cc62520bf4e7/download,University of Texas at Austin,"The additive manufacturing technologies has been facing an extraordinary growth during that last years, mainly as
consequence of the increase of low cost FDM technologies into the marketing. In contrast with that, one of the main
disadvantages of this sort of equipment is the final object finishing. For that reason, the main goal of this work is to
present and characterise the post-processing which was introduced in the marketing as smoothing. In addition, a
concise overview about the theory beneath this process is presented besides an experimental study that evaluates the
impact of this process for the main mechanical properties of object.",,,,,,
"['Mookerjee, Adaleena', 'Cohen, Daniel L.', 'Peng, David H.', 'Bonassar, Lawrence J.', 'Lipson, Hod']",2021-09-29T17:23:28Z,2021-09-29T17:23:28Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88193', 'http://dx.doi.org/10.26153/tsw/15134']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['variable-stiffness hydrogels', 'alginate printing', 'cell-seeded implants', 'surgical training', 'surgical planning', 'synthetic surgical models']",A Study of Variable Stiffness Alginate Printing for Medical Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9e32a31-02ee-4935-849e-34dc7d6a86c2/download,University of Texas at Austin,"Technologies for multi-material 3D-printing of anatomical shapes are useful
both for fabrication of heterogeneous cell-seeded implants as well as for
fabrication of synthetic models for surgical planning and training. For both these
applications, it would be desirable to print directly with biological materials to
best emulate the target’s properties. Using a novel material platform, we
describe a series of experiments attempting to print variable-stiffness hydrogels.
We vary compliances by alternating 2% alginate hydrogel and a Dextran-infused
calcium chloride post-crosslinker. Stiffness throughout the construct ranged
from 4 kPa to 20 kPa as a function of post-crosslinker concentration, which was
spatially specified by the user.",,,,,,
"['Bryant, Frances D.', 'Sui, Guanghua', 'Leu, Ming C.']",2019-10-30T16:59:07Z,2019-10-30T16:59:07Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/78194', 'http://dx.doi.org/10.26153/tsw/5283']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Rapid Freeze Prototyping,A Study on Effects of Process Parameters in Rapid Freeze Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eedbea5e-2c92-41f4-81b0-17363c0763ce/download,,"Rapid Freeze Prototyping (RFP) is a relatively new solid freeform fabrication
process, which builds a three-dimensional part according to a CAD model by depositing
and freezing water droplets layer by layer. A study on the effects of RFP process
parameters including the nozzle scanning speed, droplet size, and droplet frequency in
building ice parts with a single-nozzle work head is made. Presented in this paper are the
results of this study which indicate that these process parameters determine the ice layer
thickness and ice line width, which in turn determine the surface roughness and the
waiting time required after depositing each layer of water (i.e. between successive layers)
during the ice part building process.","This project is supported by a National Science Foundation Grant (DMI-0128313)
and a Department of Education GAANN Fellowship Grant (P200A010446).",,,,,
"['Bryant, Frances D.', 'Leu, Ming C.']",2020-02-14T15:19:42Z,2020-02-14T15:19:42Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79983', 'http://dx.doi.org/10.26153/tsw/7008']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Rapid Freeze Prototyping,Study on Incorporating Support Material in Rapid Freeze Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9a2cc7d6-8697-402a-bd1d-1be803ef2f1e/download,,"Rapid Freeze Prototyping (RFP) is a rapid prototyping method that uses water freezing
into ice to make three-dimensional parts. Each layer of a geometry is deposited and allowed to
freeze before the next layer is added. Using a support material in RFP is a relatively new
addition to the process. Validating the successful use of a support material in conjunction with
the main build material of water is presented in this paper. The support material selected for use
is a eutectic sugar solution. The selection criteria, properties, and characteristics of the support
material are discussed. Of particular interest is the diffusion between the support and main build
material, which must be minimized to an acceptable level for producing good quality,
reproducible, complex parts.",,,,,,
"['Nouri, Hadis', 'Khoshnevis, Behrokh']",2021-10-21T14:58:38Z,2021-10-21T14:58:38Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89386,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective inhibition sintering', 'inhibitor', 'polyamide']",Study on Inhibition Mechanism of Polymer Parts in Selective Inhibition Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9c376a64-dc63-44a0-84ed-fad55859efae/download,University of Texas at Austin,"The selective inhibition sintering (SIS) process is an additive manufacturing technique that builds parts
based on powder sintering. In this process parts are made upon deposition of a solution, called inhibitor, at the
boundary profile. The inhibitor prevents polymer particles to coalescence under heat exposure on each layer.
The inhibited boundary profile acts as a sacrificial mold that can be easily removed, leaving a chemically pure
part. One of the influential factors in fabrication resolution by SIS is the proper selection of an inhibitor. The
best inhibition mechanism results in ease of separation of the part from undesired regions while maintaining
part accuracy. In this paper, we investigate a framework for selecting an appropriate inhibitor for the process.
Different experiments have been performed and inhibition theory has been studied on polyamide (PA) samples.
Specifically, as an alternative to exhaustive experiments on solutions and polymers, a hybrid method based on
crystallization is proposed to characterize the effectiveness of the inhibitor. Differential Scanning Calorimetry
(DSC) tests are used to study changes in thermal properties of the samples. It is found that the sintering period
increases as crystallinity of the polymer decreases. Results show that polymer samples exposed to sodium
hypochlorite solution has longer sintering periods. Design of experiments has been used to study shrinkage
behavior of polymer samples through bulk sintering.",,,,,,
"['Zhang, Haiou', 'Rui, Daoman', 'Xie, Yang', 'Wang, Guilan']",2021-10-07T17:34:30Z,2021-10-07T17:34:30Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88490', 'http://dx.doi.org/10.26153/tsw/15424']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['metal additive manufacturing', 'metamorphic rolling mechanism', 'metamorphic rolling', 'surface deposition']",Study on Metamorphic Rolling Mechanism for Metal Hybrid Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/21ee0d1d-859d-4e6d-8c4b-b0aa19ff0cb7/download,University of Texas at Austin,"The uneven of the surface shaped by overlapping beads has been observed during metal
additive manufacturing (AM). These uneven surfaces have a cumulative effect on the accuracy of
the component in the Z-direction. Conventionally, each layer was face milled to solve the
problem, which resulted in material and time wastes. In this paper, the metamorphic mechanism
was introduced to metal additive manufacturing and a novel metamorphic rolling mechanism
with three rollers was developed. It configuration can change according to the feature of the part
to rolling the deposition upper or lateral surfaces. The influence of rolling force and rolling
temperature on the shape of bead was studied. Optimal rolling parameters were obtained to
control the height and width of overlapping beads. In addition, it is worthwhile to mention that
the hybrid deposition and rolling method will be beneficial to refine grain, avoid the hot crack
and improve the mechanical properties of parts.",,,,,,
"['Gibson, F.P.Y. Ting I', 'Cheung, W.L.']",2019-09-25T15:59:22Z,2019-09-25T15:59:22Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76000', 'http://dx.doi.org/10.26153/tsw/3099']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Conductive,Study on selective laser sintering components with electrically conductive channels,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a049e937-de4b-4a1b-b04d-2ff70816b0c9/download,,"Electrically conductive channe ls were created using conductive carbon cement (CCC) by a simple non-contact continuous deposition method on sintered DuraFormTM Polyamide parts. The deposition system consisted of a drive circuit, a Micro Inert Solenoid Valve (MIV), a nozzle head and two liquid material reservoirs. Effect of CCC/solvent ratio, speed of deposition head and sintering condition of the Polyamide base material on the electrical properties of the conductive channels were investigated. The paper will then go on to discuss how these results relate to potential applications of Selective Laser Sintering (SLS) components with electrical property.",,,,,,
"Hu, Jing",2021-11-02T20:29:01Z,2021-11-02T20:29:01Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89888,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'STL', 'cutting plane', 'slicing thickness', 'contour', 'uniform', 'adaptive']",Study on STL-Based Slicing Process for 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ccec79d1-ad88-4ef4-b7fb-2fbf7809db17/download,University of Texas at Austin,"This paper presents a framework about layer contour reconstruction algorithms by STL-based slicing process for 3D printing. The experimental results by the traditional uniform slicing
show the contour outline of each layer and comparison among the different slicing thickness of
the cutting z-plane. We then proposed a simple but effective adaptive slicing method to work on
the complicated model. Moreover, we discuss the future work to further study on addressing the
accuracy of the boundaries with the adjustment of slicing thickness.",,,,,,
"['Luo, Shuncun', 'Wang, Zemin', 'Zeng, Xiaoyan']",2021-11-18T00:53:04Z,2021-11-18T00:53:04Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90379', 'http://dx.doi.org/10.26153/tsw/17300']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['high entropy alloy', 'selective laser melting', 'microstructure', 'strength']","Study on the Formability, Microstructures and Mechanical Properties of AlCrCuFeNix High-Entropy Alloys Prepared by Selective Laser Melting",Conference paper,https://repositories.lib.utexas.edu//bitstreams/6defb58a-5cd6-4326-85fc-775b8989cc68/download,University of Texas at Austin,"Because of easy cracking caused by rapid solidification, fabricating dual-phase high-entropy alloys (DP-HEAs) through selective laser melting (SLM) has hardly been achieved.
Here we reasonably design new DP-HEAs specific to SLM according to solid solutions
formation criterion and HEA definition. Results show that Ni addition favors the formation of
face-centered cubic (FCC) phase and facilitates the transition from columnar to equiaxed grains,
thus the formability of AlCrCuFeNix (2.0 ≤ x ≤ 3.0) HEAs is improved. The SLMed
AlCrCuFeNi3.0 HEA exhibits remarkably heterogeneous microstructures, such as modulated
nanoscale lamellar or cellular dual-phase structures, and possesses the best combination of the
ultimate tensile strength (~ 957 MPa) and ductility (~ 14.3 %). Also, it is discovered that high
densities of Cr-enriched nano-precipitates are embedded in the ordered body-centered cubic
(B2) phase. Finally, the underlying strengthening mechanisms are analyzed for the SLMed
AlCrCuFeNi3.0 HEA.",,,,,,
"['Arumaikkannu, G.', 'Anilkumar, N.', 'Saravanan, R.']",2021-09-23T22:17:35Z,2021-09-23T22:17:35Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88037', 'http://dx.doi.org/10.26153/tsw/14978']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Z510 3DP rapid fabricator', 'process parameters', 'Particle Swarm Optimization', 'mechanical engineering']",Study on the Influence of Rapid Prototyping Parameters on Product Quality in 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7ba40443-dfa6-4374-833d-707679de29cf/download,,"This work aims at evaluating the relative significance of the input parameters on the product
quality produced by Z510 3DP rapid fabricator. Taguchi’s L18 orthogonal array was employed to
investigate the possible process parameters including binder setting saturation value (shell &
core), layer thickness, and build orientation. Using a surface profilometer and CMM, a series of
measurements in evaluating the 3DP products surface finish and dimensional accuracy has been
carried out. Nonlinear regression model was developed and a statistical analysis was done to
determine the significant factors affecting the product quality of the fabricated products. Optimal
process parameter settings were proposed using Particle Swarm Optimization technique. The
results were validated by conducting the confirmatory experiments.",,,,,,
"['Yang, Hwa-Joon', 'Jang, Tae-Sik', 'Ryu, Choong-Ryeol', 'Lee, Il-Yup']",2019-11-21T18:12:20Z,2019-11-21T18:12:20Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78552', 'http://dx.doi.org/10.26153/tsw/5608']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Prototype-Car,A Study on the Manufacturing of Large Size Hollow Shape Parts for Prototype-Car Using Rapid Prototyping Technology and Vacuum Molding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e113b932-d06a-43db-82e8-e3a632bb51da/download,,"Rapid Prototyping(RP) techniques have revolutionized traditional manufacturing methods.
These techniques allow the user to fabricate a part directly from a conceptual model before
investing in production tooling and help develop new models with significant short time. This
paper suggests the new process to manufacture large size hollow shape parts for prototype-car
using Rapid Prototyping technology and Vacuum Molding with the reduction of delivery time. In
addition, this paper introduces the dividing and combining method to make large size RP master
model in spite of the limit of the build chamber dimensions of commercialized RP systems and
post-processing method to achieve sufficient surface quality.",,,,,,
"['Jiang, Kaiyi', 'Guo, Yanling', 'Bourell, David L.']",2021-10-11T20:53:17Z,2021-10-11T20:53:17Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88641', 'http://dx.doi.org/10.26153/tsw/15575']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'wood plastic composite', 'microstructure', 'binding mechanism', 'energy usage', 'Eucalyptus/PES', 'mechanical interlock']",Study on the Microstructure and Binding Mechanisms of Selective Laser Sintered Wood Plastic Composite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/984fe35d-8085-4c99-9217-87b3ed271163/download,University of Texas at Austin,"A new type of wood plastic composite, Eucalyptus/PES(Polyethersulfone) blend, was
developed. It was designed to be used in LS (Laser Sintering) with reduced energy usage with
cost savings. The preparation of Eucalyptus/PES blend and part sintering were under fixed
processing conditions and parameters. Through mechanical testing, it was discovered that the
strength of prototypes is low due to the formation of a segregated structure in the composite and
a weak wood fiber–plastic particle interface.  The specific focus of this paper was on investigating the microstructure and binding
mechanisms between these two materials. Combining SEM technology and infrared spectrum
analysis, the interface binding form of the wood fiber and PES was confirmed to be mechanical
interlock. Also the size and distribution of wood fiber in the PES matrix, which can affect the
binding and strengthening mechanism, were analyzed during sintering and crack extension.",,,,,,
"Liu, Jie",2021-09-30T13:05:14Z,2021-09-30T13:05:14Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88226', 'http://dx.doi.org/10.26153/tsw/15167']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['vibration-suspense-type', 'powder-coating', 'SLS', 'Polystyrene-Al', 'Selective Laser Sintering']",Study on Vibration-Suspense-Type Metal Powder-Coating Process for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8557a8e-eee9-434a-a3d2-825bc56492d1/download,University of Texas at Austin,"In this paper, Vibration-suspense-type process is used to develop a new material, metal or
porcelain powder coated with resin or ceramic powder, then it can be sintered and formed
without large-power laser. One set of vibration-suspense-type powder-coating equipment is
developed and powder material suitable for SLS can be prepared with the equipment. The
moving status and the moving process of powder granule in the vibration-suspense-type process
are also analyzed. Based on the equipment, Polystyrene- Al powder material, which is suitable
for SLS, is successfully prepared. And the optimum process is discussed.",,,,,,
"['Sui, Guanghua', 'Zhang, Wei', 'Leu, Ming C.']",2019-09-23T16:31:26Z,2019-09-23T16:31:26Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75957', 'http://dx.doi.org/10.26153/tsw/3056']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Study on Water Deposit in Rapid Freeze Prototyping Process 342,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c477523b-155d-4770-8386-703c0a4af8eb/download,,"Rapid Freeze Prototyping (RFP) builds a three-dimensional ice part according to its CAD model by depositing and rapidly freezing water in a layer-by-layer manner. To study the water deposit in RFP, assumptions are made based on the deformation of water droplet impinging on a flat substrate, the thermal analysis of a new layer of water deposit, and the characteristics of solidification of a water drop. The equations governing the cross-sectional profile of the water deposit are then established. A model of water deposit is proposed by simplifying the equations under our experimental conditions in RFP. By using this model, equations for layer thickness of vertical and slant walls built by RFP are derived and verified by experiments",,,,,,
"['Pekin, Senol', 'Bukowski, John', 'Zangvil, Avigdor']",2019-02-28T18:38:26Z,2019-02-28T18:38:26Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73510', 'http://dx.doi.org/10.26153/tsw/660']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['FDC', 'DSC']",A Study on Weight Loss Rate Controlled Binder Removal From Parts Produced by FDC,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8a21a059-9d8e-4d76-ad86-5651204a1488/download,,"The binder removal schedule of a binder in the ethylene vinyl acetate-wax system was analyzed
by automatically adjusting the soaking duration based on the monitored weight loss of the
polymer. The thermolysis of several grades of microcrystalline wax and ethylene vinyl acetate
have been analyzed by TvA and DSC to support the explanation of the weight loss rate
controlled binder removal experiments. During the thermolysis ofsuch binders in air, the
degradation sequence is degradation and evaporation of hydrocarbons, degradation ofthe vinyl
acetate, and degradation of the ethylene chain, all oxygen assisted. It was shown that the extent
and the rate of the vinyl acetate degradation in air is determined by the molecular weight of the
EVA, unlike its degradation in N2• It was concluded that thermolysis of light polymers is easier
than that ofthe heavy ones and weight loss rate controlled binder removal technique can help in
the optimization of binder removal schedule for a variety of polymers.",,,,,,
"['Hilton, Zachary T.', 'Newkirk, Joseph W.', ""O'Malley, Ronald J.""]",2021-11-02T15:31:22Z,2021-11-02T15:31:22Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89831,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['chromium-nickel equvalency', 'Cr-Ni', 'stainless steel', 'chemistry', 'additive manufacturing']",Studying Chromium and Nickel Equivalency to Identify Viable Additive Manufacturing Stainless Steel Chemistries,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1922586b-eb06-4f1d-801f-e07121298c32/download,University of Texas at Austin,"Chromium and nickel equivalency modeling has long been used in welding to determine
the weldability of steel chemistries. A study was conducted to determine the applicability of Cr-Ni modeling to the additive manufacturing process. Many AM methods involve rapid
solidification of small melt pools, similar to welding. Chemistries with varying Cr/Ni ratios were
selected for use in a selective laser melting process and modeled using known models. Initial
results indicate that the standard “safe welding zone” may not directly apply to additive
manufacturing. The capability to build with chemistries outside the weldability “safe zone” could
result in improved and varied properties for additively manufactured materials.",,,,,,
"['Aremu, A.', 'Ashcroft, I.', 'Hague, R.', 'Wildman, R.', 'Tuck, C.']",2021-09-30T20:04:54Z,2021-09-30T20:04:54Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88291', 'http://dx.doi.org/10.26153/tsw/15232']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'finite element based topology optimisation', 'optimisation', 'structural optimization', 'alogrithm', 'SIMP algorithm', 'BESO algorithm']",Suitability of SIMP and BESO Topology Optimization Algorithms for Additive Manufacture,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c14954fb-2a4b-4c08-950d-a80433ebf9f5/download,University of Texas at Austin,"Additive manufacturing (AM) is expanding the range of designable geometries,
but to exploit this evolving design space new methods are required to find
optimum solutions. Finite element based topology optimisation (TO) is a
powerful method of structural optimization, however the results obtained tend to
be dependent on the algorithm used, the algorithm parameters and the finite
element mesh. This paper will discuss these issues as it relates to the SIMP and
BESO algorithms. An example of the application of topological optimization to
the design of improved structures is given.",,,,,,
"['Gopalakrishna, B.', 'Bourell, David L.']",2018-05-03T19:55:47Z,2018-05-03T19:55:47Z,1993,Mechanical Engineering,doi:10.15781/T27P8TX1P,http://hdl.handle.net/2152/65074,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'SFF', 'SLPS', 'Supersolidus Liquid Phase Sintering']",Supersolidus Liquid Phase Selective Laser Sintering of Prealloyed Bronze Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/061d2a9a-6c3c-4caf-8061-d5aa445abe2f/download,,,,,,,,
"['Mohajeri, Babak', 'Khajavi, Siavash H.', 'Nyberg, Timo', 'Khajavi, Siamak H.']",2021-10-18T22:44:21Z,2021-10-18T22:44:21Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89279,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'supply chains', 'supply chain modifications', 'decentralized production system']",Supply Chain Modifications to Improve Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6989efd1-cd5b-4d99-992e-a9147aab8b64/download,University of Texas at Austin,"Additive manufacturing (AM) offers unique production characteristics which among those,
toollessness and production of complex geometries are potentially significant to operations
efficiency. Previous research has illustrated the potential sufficiency of this technology to affect the
supply chains‟ arrangements and enabling decentralized production configurations. While, one of
the important advantages of AM enabled distributed production is the increased flexibility, which is
a necessity in today‟s competitive and ever changing global supply chains, number of obstacles
have kept this method from wide implementation. In this paper, we study the possible supply chain
modifications to decrease the cost of an AM-enabled decentralized production system. In other
words, we perform a cost-benefit analysis on various AM supply chain strategies in a spare parts
context to realize the independent operational factors affecting the implementation cost of additive
manufacturing. Moreover, we analyze the ways to adapt the supply chain management to enable full
potential of AM considering the present technology.",,,,,,
"['Chalsani, Kumar', 'Jones, Larry', 'Roscoe, Larry']",2018-11-02T14:19:07Z,2018-11-02T14:19:07Z,1995,Mechanical Engineering,doi:10.15781/T2JQ0TD9X,http://hdl.handle.net/2152/69330,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'fused deposition modeling process', 'STL']",Support Generation for Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa990638-73db-4ec2-be78-a7fcf546c0dd/download,,"With the growth of the use of Rapid Prototyping (RP) systems, there has been a
corresponding growth in the complexity of parts expected from the various RP processes. To
meet the demand for increasingly more intricate and detailed prototypes, the technology has
matured and improved, allowing RP users to build these parts faster, better and with a variety of
materials.
Stratasys Inc.'s Fused Deposition Modeling (FDM ®) system is one of the leading
prototyping systems available in the market today. Recent enhancements in electro-mechanical
control of the machine head have improved the viability of FDM as a system for manufacturing
complex prototypes. The FDM-1600 system can now also create detailed parts using ABS, a
widely used plastic in the automotive and other industries. In addition, we have further reduced
the lead time (preprocessing or operator time) in the product design cycle with the inclusion of an
automatic support generation module in Stratasys' proprietary QuickSlice® software product.
QuickSlice processes STL data to generate machine code to drive the FDM system.",,,,,,
"['Lufeng, Chen', 'Ruosong, Liu']",2021-12-06T23:47:05Z,2021-12-06T23:47:05Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90722', 'http://dx.doi.org/10.26153/tsw/17641']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['support-free hollowing', '3+2-axis printing', 'additive manufacturing']",Support-Free Hollowing for 3+2-Axis Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/722e0b0d-bc09-4beb-8468-a0a751969294/download,University of Texas at Austin,"Additive manufacturing (AM), also known as 3d printing, has become a hot topic in
academia and industry in the past decades. For a typical layer-based additive manufacturing
where the object is printed in a layer-by-layer fashion, the battle to reduce or even eradicate the
support structure is always faced by researchers and industrial practitioners. The newly emerging
multi-axis printing platform inspired by the five-axis machine tool opens new directions, such as
surface quality improvement, support-free printing, etc. In this paper, we have presented a
framework for the support-free hollowing of 3+2-axis printing. A suite of algorithms including
curved skeleton extraction, print sequence optimization, hollowing generation, and print path
planning is introduced. It is expected that the print efficiency will increase while the residue
artifacts caused by the support structure on the contact surface can be ultimately eradicated.",,,,,,
"['Stevinson, B. Y.', 'Bourell, D. L.', 'Beaman Jr., J. J.']",2020-02-28T21:51:16Z,2020-02-28T21:51:16Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80124', 'http://dx.doi.org/10.26153/tsw/7145']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Selective laser sintered,Support-Free Infiltration of Selective Laser Sintered (SLS) Silicon Carbide Preforms,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66063177-b704-45c2-b06f-690c0db7a00f/download,,"Non-metallic objects are often difficult to manufacture due to high melting temperatures,
poor sinterability, limited ductility, and difficulty in machining. Freeform fabrication techniques
coupled with liquid infiltration offer a cost-effective and rapid manufacturing mechanism for
composite parts with complex geometry and adequate properties. Selective laser sintered (SLS)
silicon carbide (SiC) preforms infiltrated with liquid silicon develop localized infiltrant overextrusions onto surfaces and at surface irregularities. Several shrinkage mechanisms including
densification were studied as possible causes of these overfilling extrusions, and the results are
discussed below. This research was supported by NSF Grant Number DMI-0522176.",,,,,,
"['Jangam, John Samuel Dilip', 'Anthony, Thomas', 'McKinnell, Jim', 'Pon, Ben', 'Piderman, Jake', 'Zhao, Lihua']",2023-01-27T18:01:41Z,2023-01-27T18:01:41Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117351', 'http://dx.doi.org/10.26153/tsw/44232']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Binder jetting', 'sintering', 'support structures', 'distortion']",Support-Free Sintering of 3D Printed Binder Jet Copper and Stainless Steel Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e5ffbe4b-0b60-4352-85a5-b5e571f354f1/download,,"Binder jet additive manufacturing involves selectively applying a binder, layer-by-layer, 
to produce green parts, followed by a high temperature sintering treatment. During sintering, green 
parts are inherently prone to undesired part distortion/sag in the unsupported regions. Traditional 
methods use 3D printed supports or machined ceramic setters to avoid the part distortion/sag 
during sintering. We introduce a shape-retaining-stimulus coating that will mitigate/eliminate the 
need of additional supports during sintering. Simply supported coper and stainless steel green parts 
of various thickness were evaluated for part distortion. Our experimental results demonstrate that 
a selective application of the shape-retaining-stimulus coating on 3D printed copper parts with a 
spanning up to 50 mm, and stainless steel parts spanning up to 33 mm can be sintered without 
auxiliary supports. Our shape-retaining-stimulus coating produces exceptional results, and the ease 
of removal makes it an attractive candidate.",,,,,,
"['Jangam, John Samuel Dilip', 'Anthony, Thomas', 'McKinnell, Jim', 'Pon, Ben', 'Piderman, Jake', 'Zhao, Lihua']",2023-01-31T13:56:33Z,2023-01-31T13:56:33Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117367', 'http://dx.doi.org/10.26153/tsw/44248']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Binder jetting', 'sintering', 'support structures', 'distortion']",Support-free sintering of 3D printed binder jet copper and stainless steel parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba997a29-49c0-4e21-b876-f6908c38b859/download,,"Binder jet additive manufacturing involves selectively applying a binder, layer-by-layer, 
to produce green parts, followed by a high temperature sintering treatment. During sintering, green 
parts are inherently prone to undesired part distortion/sag in the unsupported regions. Traditional 
methods use 3D printed supports or machined ceramic setters to avoid the part distortion/sag 
during sintering. We introduce a shape-retaining-stimulus coating that will mitigate/eliminate the 
need of additional supports during sintering. Simply supported coper and stainless steel green parts 
of various thickness were evaluated for part distortion. Our experimental results demonstrate that 
a selective application of the shape-retaining-stimulus coating on 3D printed copper parts with a 
spanning up to 50 mm, and stainless steel parts spanning up to 33 mm can be sintered without 
auxiliary supports. Our shape-retaining-stimulus coating produces exceptional results, and the ease 
of removal makes it an attractive candidate.",,,,,,
"Kanada, Yasusi",2021-10-19T17:49:24Z,2021-10-19T17:49:24Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89308,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['fused deposition modeling', 'layer-less', 'filament-stacking', 'horizontal stacking']",Support-less Horizontal Filament-Stacking by Layer-less FDM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/28601298-197f-48ea-9b32-797923a4a3dc/download,University of Texas at Austin,,,"This paper proposes a layer-less fused-deposition-modeling (FDM) method, which enables mostly horizontal stacking of filament without support material and which can avoid seams easily.",,,,
"['Deppe, Gereon', 'Koch, Rainer']",2021-10-26T17:58:34Z,2021-10-26T17:58:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89541,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['Multi Attribute Decision Making', 'MADM', 'additive manufacturing', 'aerospace']",Supporting the Decision Process for Applying Additive Manufacturing in the MRO Aerospace Business by MADM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e09adb4b-b2e7-4e97-b5d1-9df5022e5844/download,University of Texas at Austin,"The spare part industry in aerospace is highly demanding. For conventional
manufacturing technologies it is difficult to meet these requirements. In contrast to that, the
design freedom of Additive Manufacturing enables the production of complex and lightweight
parts. The lack of experience with this technology hampers the decision where Additive
Manufacturing can be economically applied. The cost drivers have to be newly evaluated and
holistically investigated. Supply chain advantages have to be considered during the decision
process, too. Therefore, aerospace characteristics are analyzed within the paper and a
methodology based on Multi Attribute Decision Making (MADM) is introduced. To do so, the
cost appraisal for Additive Manufacturing has to be detailed. Additionally, changes in the
supply chain have to be identified and quantified. Quality criteria have to be taken into account
as well. In the end it is shown how these influence factors can be combined to create a decision
support.",,,,,,
"['Ramos, Jorge A.', 'Bourell, David L.', 'Beaman, Joseph J.']",2019-10-25T16:10:27Z,2019-10-25T16:10:27Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77443', 'http://dx.doi.org/10.26153/tsw/4532']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Laser Polished,Surface Characterization of Laser Polished Indirect-SLS Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/349dac0c-d3da-4b14-a3b4-60aa5a379cab/download,,"Surface analysis was performed on laser polished indirect-SLS samples made
from 420 stainless steel sintered powder - bronze infiltrated. The goal was to determine
variations from the as-received condition in surface chemical composition, morphological
structure, presence of contaminants as well as the formation of new phases.
Comprehensive characterization of the laser polished surfaces was performed using
scanning electron microscopy (SEM), energy dispersive spectrochemical analysis (EDS),
x-ray diffraction analysis (XRD) and Vickers hardness. A large quantity of carbon (i.e. >
29 wt%) was present on the as-received surface mostly from the polymer binder present
in the green part. Although surface-shallow-melting is the principal mechanism for the
roughness reduction of the as-received surface, the chemical composition of the latter
after processing changed to a higher carbon and oxygen content and a lower copper
content. Additionally, clusters were formed periodically over the polished surface
consisting of Fe, Cr, Si and Al oxides. The surface analysis demonstrated that the laser
polished surfaces differ significantly more from a morphological rather than a
microstructural perspective.",,,,,,
"['Tumer, Irem Y.', 'Thompson, David C.', 'Crawford, Richard H.', 'Wood, Kristin L.']",2018-10-10T15:36:16Z,2018-10-10T15:36:16Z,1995,Mechanical Engineering,doi:10.15781/T2SJ1B965,http://hdl.handle.net/2152/68756,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'manufacturing process', 'functional prototyping']",Surface Characterization of Polycarbonate Parts from Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e7394da3-c667-410f-b732-862b881b29ce/download,,"Surfaces of polycarbonate Selective Laser Sintering parts are investigated to determine the
characteristics affecting part quality. Surfaces are obtained from experiments by varying
four factors, namely, layer thickness, laser power, part orientation, and build angle. First,
spatial modes on SLS surfaces are decomposed using a qualitative spectral analysis in an
attempt to find their origins. Thermal modes on the top surfaces of polycarbonate SLS
parts result in the other modes being obscured; melting and part curl are concluded to be
the dominant modes on these surfaces. Furthermore, surface modes resulting from building
the part at an angle to the powder bed are identified and modeled. Then, mathematical
measures are computed for the surfaces to determine surface precision quantitatively. An
analysis-of-variance study is performed to reveal the trends in surface precision with respect
to control factors. Surface precision is shown to change significantly with laser power and
part orientation, and trade-offs with part strength are presented.",,,,,,
"['Li, Yangsheng', 'Xue, Lijue']",2021-09-28T18:12:18Z,2021-09-28T18:12:18Z,9/18/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88141', 'http://dx.doi.org/10.26153/tsw/15082']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['non-contact freeform surface measurement', 'short range laser displacement sensor', 'surface measurement', 'laser displacement sensor']",Surface Contour Measurement Using a Short Range Laser Displacement Sensor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5e480f5b-3619-4581-a701-82a6b43692b5/download,University of Texas at Austin,"Non-contact freeform surface measurement is widely used in industry. To acquire the 
surface data, a laser displacement sensor and a motion system are typically used. One of the 
factors that affect the measuring accuracy is the sensor’s resolution. A high resolution sensor 
usually has a short measuring range. However, an unknown component’s profile with a large 
peak-to-valley height variation can not usually be measured using a short range sensor. 
We designed and developed a measuring system based on an existing 3-axis motion system 
with a laser displacement sensor mounted on its Z axis. This measuring system can be easily 
integrated to an existing laser processing system by standard communication ports to extend its 
applications into tool path planning, in-line inspection and monitoring. With the developed 
system, the real-time distance from the sensor to the component surface is acquired, and used as 
a feedback signal to control the sensor’s position on the Z axis to automatically maintain its 
distance with a given value. 
Through this development, the measuring range of the system is extended from the sensor’s 
measuring range up to the Z axis travelling range of the motion system so that a surface with 
large peak-to-valley height variation can be easily measured by a short range sensor with 
substantially improved accuracy.",,,,,,
"['Shi, Dongping', 'Gibson, Ian']",2019-02-18T17:44:28Z,2019-02-18T17:44:28Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73393', 'http://dx.doi.org/10.26153/tsw/545']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Selective Laser Sintering']",Surface Finishing of Selective Laser Sintering Parts with Robot,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f6e399c1-9702-410b-b161-ff5173b9b9d8/download,,"Compared with conventional subtractive manufacturing technologies, RP has great benefits
in shortening the design-manufacture cycle time of a product. Even ifmechanical properties are
not considered, most RP products still cannot be directly used in applications until the
requirements for overall surface quality are satisfied. To improve the overall surface quality of
Selective Laser Sintering parts, a robotic finishing system has been developed as a part of an
ongoing research project. A finishing tool is held by a robot and moved according to
programmed paths generated from the original CAD model data. This paper describes the
experimental system in detail and shows that the surface roughness, dimensional accuracy, and
geometrical accuracy can be improved.",,,,,,
"['Vaithilingam, Jayasheelan', 'Goodridge, Ruth D.', 'Christie, Steven D.', 'Edmondson, Steve', 'Hague, Richard J.M.']",2021-10-05T19:16:21Z,2021-10-05T19:16:21Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88414', 'http://dx.doi.org/10.26153/tsw/15353']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'SLM', 'self-assembled monolayers', 'SAMs']",Surface Modification of Selective Laser Melted Structures Using Self-Assembled Monolayers for Biomedical Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2c41bf7a-9a7d-4570-ab3c-6340894a81f9/download,University of Texas at Austin,"The potential of the selective laser melting (SLM) process to fabricate biomedical implants
has been studied widely in recent years due to its ability to build complex and customised
structures. Although SLM is capable of building almost any desired geometry, the surface
properties of the produced parts are not controlled by the process and may not be suitable for
many applications. Hence in this study, the coating of self-assembled monolayers (SAMs)
onto SLM fabricated Ti6Al4V structures to modify surface chemistry has been studied. 16-phosphanohexadecanoic acid monolayers were used to modify SLM as-fabricated (SLM-AF)
and mechanically polished (SLM-MP) surfaces. X-ray photoelectron spectroscopy (XPS) and
static water contact angle measurements confirmed the formation of monolayers on these
surfaces. The covalently bonded monolayers were found to be stable for up to six weeks
immersion in Tris-HCl buffer solution. Stability of monolayers on SLM-AF and SLM-MP
was not significantly different. This study demonstrates the possibility of forming stable
phosphonic acid monolayers on SLM fabricated Ti6Al4V surfaces.",,,,,,
"['Han, C.J.', 'Chen, X.', 'Tan, J.W.', 'Yao, Y.', 'Wei, Q.S.', 'Zhang, Z.', 'Shi, Y.S.']",2021-10-20T21:42:23Z,2021-10-20T21:42:23Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89368,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'Co-Cr scaffold', 'surface modification', 'bone implants']",Surface Modification on a Porous Co-Cr Scaffold Fabricated by Selective Laser Melting for Bone Implant Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/59d02da5-d4ab-44db-8753-b48f5a8e4f17/download,University of Texas at Austin,"Cobalt–chromium–molybdenum alloys with porous structures can be fabricated by additive
manufacturing technique, which are attractive for use as scaffolds for bone implant applications. However,
metallic implant are difficult to bond directly to living bone due to limited implant interface problems.
Therefore, surface modification with scaffold material is required to improve bio-compatibility and the interface
surface. In this study, a porous Co-Cr scaffold fabricated by selective laser melting was modified by
electrodeposition with biocompatible silk fibroin. The surface characteristics of porous scaffold before and after
surface modification were evaluated with the atomic force microscopy, scanning electron microscopy, X-ray
diffraction, water contact angle measurement. The mechanical properties including elastic modulus and
compressive strength, were determined by compression tests.",,,,,,
"['Jagdale, Shweta Hanmant', 'Theeda, Sumanth', 'Ravichander, Bharath Bhushan', 'Kumar, Golden']",2023-03-28T19:21:07Z,2023-03-28T19:21:07Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117667', 'http://dx.doi.org/10.26153/tsw/44546']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Laser Powder Bed Fusion', 'SS316L', 'Microhardness', 'Design of Experiments', 'Taguchi', 'Surface Roughness']",Surface Morphology and Hardness of Powder Bed Fused Ss316l as a Function of Process Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9582502-f88a-44b5-89c4-f63cf985b406/download,,"Laser powder bed fusion is an emerging additive manufacturing process to fabricate fully dense 
complex metal parts with high accuracy. Laser process parameters such as, laser power, hatch 
spacing, scan speed, scan strategy and layer thickness play a major role in defining the quality of 
the as-built parts. Stainless steel 316L (SS316L) is known for its excellent corrosion resistance, 
high tensile strength, and high-performance at elevated temperatures. SS316L is used in many 
applications in the field of automotive, aerospace, medical and heavy equipment industries. In the 
current study, experiments are designed using Taguchi method to understand the effect of process 
parameters on the mechanical properties of as-built SS316L parts. Surface roughness of as-built 
parts is characterized by using digital optical microscopy. The relative density and Vickers 
microhardness are measured for the as-built parts. Finally, an optimal processing region for laser 
process parameters is identified.",,,,,,
"['Kyogoku, H.', 'Shimizu, Y.', 'Yoshikawa, K.']",2021-10-12T17:52:39Z,2021-10-12T17:52:39Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88705', 'http://dx.doi.org/10.26153/tsw/15639']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'surface morphology', 'titanium', 'process parameters', 'process map']",Surface Morphology of Selective Laser-Melted Titanium,Conference paper,https://repositories.lib.utexas.edu//bitstreams/179c9679-f33e-4d5c-b403-03165d36ee91/download,University of Texas at Austin,"The surface morphology of biomaterials is one of the most important biocompatibility
factors. In this paper, the change in surface morphology of selective laser-melted titanium with
process parameters was investigated to control the pore structure and mesh size. First, the process
map which shows the relation between the morphology of laser-melted track and the process
parameters such as laser power and scan speed was drawn by experiments. The laser-melted layer
was fabricated on the basis of the process map. As a result, the surface morphology, especially
pore structure and mesh size, of the layer is affected strongly by energy density as well as scan
spacing.",,,,,,
"['Chen, Runrun', 'Fernandes, Axel', 'Ma, Changyu', 'Huang, Shuyi', 'Zheng, Shiqi', 'Barros, Natan', 'Ho, Nhut', 'Li, Bingbing']",2023-02-09T19:05:35Z,2023-02-09T19:05:35Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117443', 'http://dx.doi.org/10.26153/tsw/44324']",eng,2022 International Solid Freeform Fabrication Symposium,Open,bone,Surface Polishing for Additively Manufactured Titanium Bone Scaffolds to Improve Osseointegration,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d958a7ab-1f8d-48e8-99c9-de32b6bb507e/download,,"This research focuses on the porous design, metal additive manufacture and surface 
polishing methods of Ti6Al4V alloy scaffolds for bone implants and tissue regeneration, with 
varying lattice structures and pore sizes in the range of 250-350 microns using a selective laser 
melting (SLM) system Renishaw AM400. Lack of fusion in additive manufacturing results in 
partially sintered metal particles on both interior and exterior surfaces of porous titanium scaffolds, 
which necessitates the investigation of seeking an effective polishing method for removing the 
partially melted particles on the surface of an intricate designed porous implant to achieve a better 
surface morphology and roughness that augments osseointegration. In this paper, three polishing 
methods were examined. The experimental result shows that the electropolishing method is 
capable of effectively removing the incompletely fused particles but it is noteworthy that the 
parameters controlled during the experiment are crucial to preserve the lattice structure. Rotary 
abrasive flow polishing method is worth investigating in depth, if better control the direction and 
rate of flow, the better surface morphology and roughness can be achieved. Lastly, the ultrasonic 
polishing method was explored to investigate the dependence on the vibratory amplitude control.",,,,,,
"['Eidt, Wesley', 'Tatman, Eric-Paul', 'McCarther, Josiah', 'Kastner, Jared', 'Gunther, Sean', 'Gockel, Joy']",2021-11-30T21:07:30Z,2021-11-30T21:07:30Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90550', 'http://dx.doi.org/10.26153/tsw/17469']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['surface roughness', 'process parameter', 'laser powder bed fusion', 'additive manufacturing']",Surface Roughness Characterization in Laser Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e22271d7-bd0c-4d9a-81bd-e4705ca06323/download,University of Texas at Austin,,,This work investigates the influence of processing parameters on the surface roughness for vertical surfaces and surfaces at a downward facing angle.,,,,
"['Ramos, J.A.', 'Murphy, J.', 'Wood, K.', 'Bourell, D.L.', 'Beaman, J.J.']",2019-10-09T15:57:03Z,2019-10-09T15:57:03Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76144', 'http://dx.doi.org/10.26153/tsw/3233']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Enhancement,Surface Roughness Enhancement of Indirect-SLS Metal Parts by Laser Surface Polishing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1fc8cfc8-5634-43b0-8dfd-56e87b063f38/download,,"Laser polishing by means of shallow surface melting of indirect-SLS metal parts
was achieved using high power CO2 and Nd:YAG lasers raster scanned at high speed.
This was an effective technique for reducing surface roughness. The fast moving laser
beam provides just enough heat energy to cause melting of the surface peaks. The molten
mass then flows into the surface valleys by surface tension, gravity and laser pressure,
thus diminishing the roughness. Surface roughness Ra data were obtained by
profilometry measurements of the polished samples. An analytical model was developed
based on the assumption that the surface of an SLS part consists of semi-spherical caps.
The model was used to predict the Ra values as a function of laser power, scan speed and
precursor powder particle size. The modeled results fit the empirical data within a 15%
error.","The Laboratory of Freeform Fabrication gratefully acknowledges the support of
the Office of Naval Research for funding the project “Surface Engineering for SFF
Processes”, Grant Nº: N00014-00-1-0334",,,,,
"['Delfs, P.', 'Töws, M.', 'Schmid, H.-J.']",2021-10-21T18:31:50Z,2021-10-21T18:31:50Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89421,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'surface quality', 'building orientation', 'layer alignment']",Surface Roughness Optimized Alignment of Parts for Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b45d0cb4-8310-4603-9fcd-3295d3335c80/download,University of Texas at Austin,"The layered structure of Additive Manufacturing processes results in a stair-stepping effect of the surface topographies. In general the impact of this effect
strongly depends on the build angle of a surface, whereas the overall surface roughness is caused by the resolution of the specific AM process. The aim of this work is
the prediction of the surface quality in dependence of the building orientation of a
part. These results can finally be used to optimize the orientation to get a desired
surface quality. As not every area of a part can be optimized, a predetermination
of areas can be used to improve the surface quality of important areas. The model
uses the digital STL format of a part as this is necessary for all AM machines to
build it. Each triangle is assigned with a roughness value and by testing different
orientations the best one can be found. This approach needs a database for the
surface qualities. This must be done separately for each Additive Manufacturing
process and is shown exemplary with a surface topography simulation for the laser
sintering process.",,,,,,
"['Evans, Rachel', 'Gockel, Joy']",2021-12-01T22:59:00Z,2021-12-01T22:59:00Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90647', 'http://dx.doi.org/10.26153/tsw/17566']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['surface roughness', 'processing parameters', 'layer geometry', 'laser powder bed fusion', 'additive manufacturing']",Surface Roughness Variation in Laser Powder Bed Fusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/43528753-f2f6-4233-9d7c-89324235e0a2/download,University of Texas at Austin,"The surface roughness of an additively manufactured part produced through laser powder
bed fusion has a significantly higher roughness than surfaces produced through traditional
manufacturing processes. This roughness can have a significant impact on mechanical properties
such as the fatigue life. Additionally, there is still a lack of understanding of the variation of the
surface roughness and the appropriate metrics to represent the surface. This work presents line of
sight measurements across several large surfaces with changing processing parameters and layer
geometry. The measured areas are divided into regions where surface measurement metrics are
calculated, and the surface variation within and across the surface is discussed. The calculated
metrics and variation are related to the expected impact that the surface will have on the mechanical
performance. Results from this research will provide guidance towards surface roughness metric
specifications to ensure quality parts with consistent mechanical performance.",,,,,,
"['Nuttall, D.W.', 'Elliott, A.M.', 'Post, B.K.', 'Love, L.J.']",2021-11-01T22:12:07Z,2021-11-01T22:12:07Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89776,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['surface scanning', 'digital scanning', 'large-scale 3D printing', 'large-scale FDM printing', 'fused deposition modeling', 'watercraft layup tooling']",Surface Scanning Methods and Large-Scale FDM Printing for the Replication of Watercraft Layup Tooling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/41ec7115-d465-4b9f-98fc-9fa96864fdab/download,University of Texas at Austin,"The manufacturing of tooling for large, contoured surfaces for fiber-layup applications
requires significant effort, with traditional methods for the auto industry using hand sculpted
clay, and the marine pleasure-craft industry typically creating forms from foam lay-up, then hand
cut or machined down from a billet. Oak Ridge National Lab’s Manufacturing Demonstration
Facility (ORNL MDF) collaborated with Magnum Venus Products to develop a process for
reproducing legacy whitewater adventure craft via digital scanning and large scale 3-D Printing
molds. The process entailed scanning a legacy canoe, converting to CAD, additively
manufacturing the mold, and subtractively finishing the transfer surfaces. The outlined steps
were performed on a specific canoe geometry, with intent to develop energy efficient,
marketable processes for replicating complex shapes related to watercraft, and provide products
for demonstration to the composites industry. It is anticipated that developing this process to
manufacture tooling for complex contoured surfaces will have direct applicability to the
sports/pleasure craft industry, naval and other watercraft, as well as bathrooms and large trucks.",,,,,,
"['Sachs, Emanuel', 'Curodeau, Alain', 'Gossard, David', 'Jee, Haeseong', 'Cima, Michael', 'Caldarise, Salvatore']",2018-09-26T19:55:23Z,2018-09-26T19:55:23Z,1994,Mechanical Engineering,doi:10.15781/T2SN01P5J,http://hdl.handle.net/2152/68591,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['3D Printing', 'metal matrix', 'CAD']",Surface Texture by 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/05ec48e2-c415-4fa2-8ea2-1489ff9abb7b/download,,"Three Dimensional Printing is a solid freeform fabrication process which creates parts
directly from a computer model by depositing in layers. Each layer is created by depositing
powder and selectively joining the powder with binder applied by a modulated ink-jet
printhead. This paper explores the application of 3D Printing to the manufacture of surface
textures, where the geometric freedom of 3D Printing is used to create repetitive millimeter
and sub-millimeter surface structures with overhangs and undercuts. A related aspect of
the work concerns the development of computer representations of these complex
structures.
In one investigation, a ""mushroom field"" surface texture was modeled and printed. Each
mushroom consists of a cylinder with a ball on top. These features are printed in a
hexagonal array with each feature parallel to the local surface normal of a complex curved
surface. In another investigation, textures were printed into ceramic molds. The textures
were transferred to metal (tin-lead, CoCr) castings as positive surface features with
overhangs and undercuts and typical dimensions of 700 x 350 x 350Jlm. The application
ofsuch cast textures to bone flXation in orthopaedic implants is discussed.",,,,,,
"['Yang, Li', 'Gu, Hengfeng', 'Lassell, Austin']",2021-10-12T21:45:35Z,2021-10-12T21:45:35Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88749', 'http://dx.doi.org/10.26153/tsw/15683']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['electropolishing', 'surface treatment', 'Ti6Al4V', 'powder bed fusion', 'direct metal laser sintering', 'electron beam melting', 'additive manufacturing']",Surface Treatment of Ti6Al4V Parts Made By Powder Bed Fusion Additive Manufacturing Processes using Electropolishing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7185cea7-7b06-462f-aab9-684f519b93ac/download,University of Texas at Austin,"This paper investigated the use of electropolishing on the surface treatment of the Ti6Al4V parts made
by the powder bed fusion processes including direct metal laser sintering (DMLS) and electron beam
melting (EBM). A non‐aqueous alcohol based electrolyte was used, and the relationship between the
process and surface roughness was evaluated. Based on the results, the feasibility of electropolishing as
a potential alternative post‐surface treatment for additive manufactured metal parts was discussed.",,,,,,
"['Reutzel, E.W.', 'Nassar, A.R.']",2021-10-12T22:17:30Z,2021-10-12T22:17:30Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88753', 'http://dx.doi.org/10.26153/tsw/15687']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['metal-based additive manufacturing', 'additive manufacturing', 'laser-based deposition', 'directed-energy deposition', 'closed-loop control', 'build-plan']","A Survey of Sensing and Control Systems for Machine and Process Monitoring of Directed-energy, Metal-based Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/d8519e5b-7b0e-4aa2-87b6-1925bed79cf5/download,University of Texas at Austin,"Additive manufacturing of metal parts is, even in the simplest of cases, a complex undertaking.
Parts typically involve hundreds or thousands of individual laser or electron-beam deposits, each
of which involve a complex interaction between energy source, feedstock, and substrate. During
deposition, many of the independent process variables that contribute to overall build quality—
such as travel speed, feedstock flow pattern, energy distribution, gas pressure, etc.—are subject to
perturbations from systematic fluctuations (such as changing build geometry or growing global
temperature) and random external disturbances (such as spatter on a cover lens). Such process
variations affect final part quality, including dimensional tolerance, microstructure, and
properties. Researchers have utilized a wide variety of sensor data and analysis for quality
monitoring and real-time control of the component geometry, microstructure, and properties.
Process attributes that have been targeted for measurement and control include melt pool
geometry, temperature, and layer build-height; process parameters that have been utilized for
control include processing-head stand-off, substrate angle, travel speed, material feed-rate, and
beam power. Here, we survey many of these methods for laser-based, directed-energy
deposition, and briefly discuss recently-introduced methods for real-time, closed-loop control of
build-plan.",,,,,,
"['Sreenivasan, Rameshwar', 'Bourell, David L.']",2021-09-28T19:36:04Z,2021-09-28T19:36:04Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88163', 'http://dx.doi.org/10.26153/tsw/15104']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['sustainability', 'Selective Laser Sintering', 'energy standpoint', 'electrical power', 'Eco-Indicators']",Sustainability Study in Selective Laser Sintering – An Energy Perspective,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8ff8c21a-ed8d-4e58-ab88-a01353157298/download,University of Texas at Austin,"This paper presents a sustainability analysis of Selective Laser Sintering (SLS)
from an energy standpoint. Data of electrical power consumed by the system over an
entire build were acquired using a LabVIEW 8.6 circuit. The power drawn by individual
subsystems were also measured, and an energy balance was performed. These data were
then used to arrive at a Total Energy Indicator of the process with the help of a specific
type of Environmental and Resource Management Data (ERMD) known as Eco-Indicators, which indicates the level of sustainability of the process.",,,,,,
"['Lau, Sharon', 'Yeazel, Taylor', 'Miller, Ana', 'Pfister, Nathan', 'Rivero, Iris V.']",2021-11-09T21:01:11Z,2021-11-09T21:01:11Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90165', 'http://dx.doi.org/10.26153/tsw/17086']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'pores', 'polyvinyl alcohol', 'PVA', 'hydrogel', 'cross-linking']",A Sustainable Additive Approach for the Achievement of Tunable Porosity,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a74e1ca-0b7a-466f-8a4b-d38be5916438/download,University of Texas at Austin,"This study aims to design a green additive approach for the fabrication of controlled porosity on
hydrogels. Although hydrogels have been of common use in tissue engineering, the generation of
controllable porosity remains an issue due to their swelling and degradation properties. Hydrogels
in this study were fabricated by physical cross-linking and the porosity was generated by casting
the solution in a 3D printed mold prior to physical cross-linking. This approach eliminates the use
of chemical cross-linking compounds which are often toxic and not environmentally friendly.
Polyvinyl alcohol was selected to validate this technique due to its biocompatibility and adequate
mechanical properties. The microstructure, mechanical properties and deformation of the porous
hydrogels were characterized. Results revealed that the proposed bioplotting technique reduced
variation of pore size and allotted for the realization of controlled and tunable pore structures.",,,,,,
"['Heidrich, James R.', 'Gervasi, Vito', 'Kumpaty, Subha']",2019-10-18T17:05:17Z,2019-10-18T17:05:17Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76263', 'http://dx.doi.org/10.26153/tsw/3352']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Tetralattice,Synthesis of a Compact Tetralattice Heat Exchanger using Solid Freeform Fabrication and Comparison Testing Against a Tube Heat Exchanger,Conference paper,https://repositories.lib.utexas.edu//bitstreams/09d9febc-b516-4871-b6d6-d19ad7b937f0/download,,"The challenge for Solid Freeform Fabrication (SFF) lies in fabricating complex parts that are not
possible by conventional manufacturing means. The goal was to apply SFF techniques to
complex geometry heat exchangers. The heat exchanger structure is modeled after the
covalently bonded carbon atoms of a diamond. The tetrahedron diamond lattice, or Tetralattice,
is a repeating lattice unit that forms a network of channels to form the heat exchanger.
Electroforming methods creating Tetralattice were applied to synthesize an air-oil compact heat
exchanger. After production, the heat exchanger was tested and compared with an industry
standard heat exchanger for performance evaluation.",,,,,,
"['Agarwala, Mukesh K.', 'Bourell, David L.', 'Manthiram, Arumugam', 'Birmingham, Britton R.', 'Marcus, Harris L.']",2018-05-03T20:00:42Z,2018-05-03T20:00:42Z,1993,Mechanical Engineering,doi:10.15781/T2QR4P760,http://hdl.handle.net/2152/65078,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Center for Materials Science and Engineering', 'conductors', 'Selective Laser Sintering']","Synthesis, Selective Laser Sintering and Infiltration of High Super Tc Dual Phase Ag-YBa2Cu307-x Superconductor Composites",Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb073840-6090-4ac3-811d-883beaec374f/download,,"Fine, homogeneous dual phase Ag-YBa2Cu307-x composite powders were prepared by a simple
colloidal sol-gel co-precipitation technique. Silver did not react with or degrade YBa2Cu307-x.
Bulk porous samples of pure YBa2Cu307-x and Ag-YBa2Cu307-x were made from powders by
Selective Laser Sintering. The porous parts were further densified by infiltrating silver into pores,
resulting in a dense, structurally sound dual phase superconducting composite. Laser processing
parameters were varied to obtain optimum microstructure. The laser sintered parts required oxygen
annealing after infiltration to restore the orthorhombic, superconducting structure. X-ray
diffraction and Tc measurements indicate some impurity phases present in samples processed
under aggressive laser conditions.",,,,,,
"['Foroozmehr, Ehsasn', 'Sarrafi, Rouzbeh', 'Hamid, Syed', 'Kovacevic, Radovan']",2021-09-29T14:21:57Z,2021-09-29T14:21:57Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88180', 'http://dx.doi.org/10.26153/tsw/15121']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['metal-ceramic composites', 'laser cladding', 'powder deposition', 'slurry erosion']",Synthesizing of Functionally Graded Surface Composites by Laser Powder Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/915aa3ae-a5e3-4598-bb69-2c584df813c8/download,University of Texas at Austin,"Metal-ceramic composites are used extensively in surface modification. Laser cladding, as one of the surface treatment
techniques, shows a promising method to deposit functionally graded layers of metal-ceramic composite. In this study,
AISI 4140 and nickel as the matrix and tungsten carbide (WC), titanium carbide (TiC), and nano-WC as the ceramic
parts are used in four different combinations for deposit on AISI 4140 substrates. The volume percentage of the
ceramics is increased from the bottom to the top. The microstructure and micro-hardness of the samples and residual
stress of the top surface of the samples are studied and compared.",,,,,,
"['Qu, Xiuzhi', 'Langrana, Noshir A.']",2019-10-18T15:13:58Z,2019-10-18T15:13:58Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76234', 'http://dx.doi.org/10.26153/tsw/3323']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Extrusion-Based,A System Approach in Extrusion-Based Multi-Material CAD,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b262d1e-35f2-4c19-9203-08bf2c901ec2/download,,"For extrusion based multi-material Layered Manufacturing (LM) processes, a CAD system has
been developed for the Fused Deposition of Multiple Ceramics (FDMC) hardware. This closed
loop CAD system includes solid model design & multi-material slicing, multi-material toolpath
generation and virtual simulation modules. Intelligent features and an adaptive roadwidth
optimum toolpath generation algorithm compute void sizes & their location and generate a void
free toolpath [1][2]. The present study focuses on a comprehensive approach, which includes a
format that contains the information on the geometry of the multi-material components, the build
materials and the necessary fabrication process information. Multi-CAD utilizes computer
graphics techniques to visualize the fabricated part. The slicing algorithm is utilized to create
multi-material contours, which then are integrated into our previously developed intelligent toolpath system.",,,,,,
"['Seltzer, D.M.', 'Wang, X.', 'Nassar, A.R.', 'Schiano, J.L.', 'Reutzel, E.W.']",2021-10-20T21:00:04Z,2021-10-20T21:00:04Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89361,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['metal-based additive manufacturing', 'part quality', 'feedback control', 'scanning speed', 'laser power', 'melt pool']","System Identification and Feedback Control for Directed-Energy, Metal-Based Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc7b2069-ecb9-4332-bc17-9b38b3bca032/download,University of Texas at Austin,"Additive manufacturing of metal parts is a complex process where many variables
determine part quality. In addition to manipulated process variables, such as travel speed,
feedstock flow pattern, and energy distribution, other exogenous inputs also determine part quality.
For example, changing build geometry and a growing global temperature. In addition, there are
random external disturbances such as spatter on a cover lens. Both manipulated process variables
and exogenous inputs affect dimensional tolerance, microstructure, and other properties that
determine the final part quality. Our long term aim is to improve part quality through real-time
regulation of measurable process variables using vision-based feedback control. As a starting
point, we present a process model that relates scanning speed and laser power to build height and
melt pool width. These results demonstrate the necessity for using multi-input multi-output
feedback control techniques and provide information for refining the frame rate and spectral
sensitivity of the imaging system.",,,,,,
"['Habbal, Osama', 'Kassab, Ali', 'Ayoub, Georges', 'Mohanty, Pravansu', 'Pannier, Christopher']",2024-03-26T20:18:39Z,2024-03-26T20:18:39Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124392', 'https://doi.org/10.26153/tsw/51000']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['fused filament fabrication', 'additive manufacturing', 'extrusion dynamics', 'spreading dynamics']",System Identification of Fused Filament Fabrication Additive Manufacturing Extrusion and Spreading Dynamics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/443870c3-b62a-49dc-b49f-48dafb3dd18e/download,University of Texas at Austin,"In fused filament fabrication additive manufacturing, polymer extrusion and spreading dynamics affect
build quality in both surface finish and mechanical properties. The state of the art in extrusion modeling
and control is identification and compensation of a fixed first order pole with a linear model of the
system. However, physical nonlinearities cause deviation of this pole in practice. To advance the aim of
slicing using accurate nonlinear dynamic models, this work presents a system and procedure for
automated measurement of dynamic bead extrusion. The system uses a belt printer, iFactory3D One Pro,
with nozzle tilted 45 degrees from the build belt, and a snapshot 3D scanner. Single layer prints in
polylactic acid (PLA) are scanned and then automatically ejected. The gcode for the single bead print
holds the gantry speed fixed or extrusion speed constant while the extrusion flow rate or gantry speed is
varied as a step input signal in space. The experiment design matrix varied two variables: gantry speed
and extrusion flow rate. Time constants are fitted to bead area signals that are extracted from the scan data
to obtain nonlinear models. Depending on the experiment condition, the percent difference between the
highest time constant and the lowest time constant ranged from 279% to 61%, confirming the high
nonlinearity of the extrusion system in FFF 3D printers. Additionally, measurements are performed on a
cartesian 3D printer with a 2D scanner to test applicability of the methods to a general audience and
verify observed trends. It was observed that larger steps in extrusion velocity for a constant X-Axis
velocity, yielded smaller time constants, while the same steps in velocity using a constant extrusion
velocity condition with variable X-Axis velocity, yielded the opposite trend. Moreover, the time constants
for a step up in extrusion velocity yielded higher overall values in time constant when compared to step
down conditions.",,,,,,
"['Boddu, Mallikharjuna R.', 'Landers, Robert G.', 'Musti, Srinivas', 'Agarwal, Sanjeev', 'Ruan, JianZhong', 'Liou, Frank W.']",2019-10-25T16:00:38Z,2019-10-25T16:00:38Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77438', 'http://dx.doi.org/10.26153/tsw/4527']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Laser Aided,System Integration and Real-Time Control Architecture of a Laser Aided Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/546170f8-c443-4273-810d-1a750c9381eb/download,,"This paper discusses a hybrid deposition–removal manufacturing system being developed at the
University of Missouri–Rolla. The system consists of a laser system, five–axis CNC machining
center, and powder feeder system. A description of the control software, real–time control
architecture, and integration of various subsystems to build the hybrid system is given. The
interaction of the real–time controller with various sensors and subsystems to monitor and
regulate the process is presented. The communication between integrated process planning for
the system and real–time control is also discussed in this paper.","The authors gratefully acknowledge the financial support of the National Science Foundation
(DMI–9871185), Missouri Research Board, Society of Manufacturing Engineers (#02022–A),
and Missouri Department of Economic Development.",,,,,
"['Ardis, Abel', 'Alvarez Andrade, Andres', 'McNamara, Justin', 'Ahrens, Anthony', 'Janysek, Jason', 'Humble, Jamie', 'Asiabanpour, Bahram']",2021-10-11T22:23:15Z,2021-10-11T22:23:15Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88666', 'http://dx.doi.org/10.26153/tsw/15600']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['reverse engineering', 'fabricated parts', 'part accuracy', 'feature taxonomy', 'trend error']",A Systematic Use of Reverse Engineering in Evaluating the Overall Accuracy of the Fabricated Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/80b3711d-c716-4676-8685-ca96d807f394/download,University of Texas at Austin,"In this paper a systematic approach is proposed that evaluates the overall accuracy of a part. In
this approach, by using the feature taxonomy, a part is decomposed into primitive features. Then,
each feature is compared to the original CAD. Features are evaluated based on their size, form,
orientation, and position. Laser scanning technique is used to collect a feature’s data and its
conversion into CAD data. To reduce data processing time for non-freeform features, manual
digital dial indicators were customized and used for data collection. To process and evaluate the
part’s accuracy, statistical and CAD methods are applied. One benefit of the proposed hybrid
system is that different errors can be differentiated and separated. In this study the manual
method and statistical line fitting showed that, in addition to the surface quality deviation error,
there was a trend error in the data; as the part got closer to the front right side of the printer it was
steadily increasing. Further observations clarified that the trend error is caused by the build
orientation; as the printer lays down a new layer of powder it drags the previous layer binder and
powder from the back of the printer to the front of the printer.",,,,,,
"['Lieneke, T.', 'Adam, G.A.O.', 'Leuders, S.', 'Knoop, F.', 'Josupeit, S.', 'Delfs, P.', 'Funke, N.', 'Zimmer, D.']",2021-10-19T20:38:02Z,2021-10-19T20:38:02Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89334,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'dimensional tolerance', 'dimensional deviations', 'linear dimensions']",Systematical Determination of Tolerances for Additive Manufacturing by Measuring Linear Dimensions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b67e6f84-9ebb-4d68-92d1-42a9a75dca11/download,University of Texas at Austin,"Additive manufacturing offers many technical and economical benefits. In order to profit
from these benefits, it is necessary to consider the manufacturing limits and restrictions. This
applies in particular to the geometrical accuracy. Therefore, the achievable geometrical accuracy
needs to be investigated, which enables the determination of realistic tolerances. Thus, two
different aims are considered. The first aim is the determination of dimensional tolerances that can
be stated if additive manufacturing is used under normal workshop conditions. Within the second
aim, relevant process parameters and manufacturing influences will be optimized in order to reduce
dimensional deviations. To achieve both aims a method was developed first. This method identifies
relevant influential factors on the geometrical accuracy for the processes Fused Deposition
Modeling (FDM), Laser Sintering (LS) and Laser Melting (LM). Factors were selected that are
expected to affect the geometrical accuracy mainly. The first investigations deal with measuring
linear dimensions on a designed test specimen and the derivation of achievable dimensional
tolerances. This paper will present both, the developed method and the first results of the
experimental investigations.",,,,,,
"Wozny, Michael",2018-04-18T17:31:23Z,2018-04-18T17:31:23Z,1992,Mechanical Engineering,doi:10.15781/T2X63BP0R,http://hdl.handle.net/2152/64363,eng,1992 International Solid Freeform Fabrication Symposium,Open,"['CAD model', 'CAD geometry', 'SFF']",Systems Issues in Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/266f5e65-0a9d-4368-9b37-2b9ec2044cf7/download,,"This paper is concerned with the systems aspects of the Solid Freeform Fabrication (SFF) technology, i.e., the issues that deal with getting an external geometric CAD model to automatically control the physical layering fabrication process as directly as possible, regardless ofthe source of the model. The general systems issues are described, the state of systems research is given, and open research questions are posed.",,,,,,
"['Li, X.P.', 'Dadbakhsh, S.', 'Vanmeensel, K.', 'Vleugels, J.', 'Van Humbeeck, J.', 'Kruth, J.P.']",2021-11-02T14:09:12Z,2021-11-02T14:09:12Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89808,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['commercially pure titanium', 'Mo2C', 'selective laser melting']",Tailoring Commercially Pure Titanium Using Mo2C During Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e9223372-88a9-454d-84b2-b5355b409279/download,University of Texas at Austin,"Commercially pure Ti (CP Ti), Ti alloys and Ti composites have applications in a wide
range of industries. With the merits of the emerging additive manufacturing technique, e.g. layer-wise fabrication and rapid solidification rate, the fabrication of Ti composites with tailorable
microstructure and hence controllable properties is possible. In this work, a Ti composite was
fabricated through selective laser melting (SLM) of CP Ti with Mo2C, consisting of a matrix
mainly from α-Ti and a small amount of β-Ti which could potentially embed very fine existing
particles. The influence of SLM on the phase formation and microstructure of the fabricated Ti
composite was investigated. The results showed that a tailorable microstructure of the Ti
composite can be achieved via SLM. This work provides fundamental and important information
on the fabrication of Ti composites with controllable microstructure through SLM of CP Ti with
ceramic particle additions.",,,,,,
"['Quiñonez, Paulina A.', 'Bermudez, Diego', 'Ugarte-Sanchez, Leticia', 'Roberson, David A.']",2021-11-18T01:48:58Z,2021-11-18T01:48:58Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90400', 'http://dx.doi.org/10.26153/tsw/17321']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['shape memory polymers', 'physical properties', 'fused deposition modeling', 'additive manufacturing']",Tailoring Physical Properties of Shape Memory Polymers for FDM-type Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bfdb14aa-f0da-485a-9acb-88a9a7faaa41/download,University of Texas at Austin,"Inclusion of shape memory polymers into additive manufacturing technologies based on
fused deposition modeling (FDM™) can greatly increase the usefulness of this fabrication
platform. Materials compatible with FDM™ such as polylactic acid (PLA) are known to exhibit
shape memory properties, however aspects such as shape recovery and shape fixation are not
tunable. The work presented here entails the initial development and characterization of shape
memory polymers intended for FDM™-type additive manufacturing platforms. Here, two
polymers with differing shape memory mechanisms (dual component and dual state) were
combined in iterative ratios leading to material systems with tunable physical properties. Dynamic
mechanical analysis (DMA) was used to determine the critical thermal parameters while polymer
crystallinity was determined via x-ray diffraction (XRD). Scanning electron microscopy (SEM)
was used to characterize the fracture morphology of impact test specimen.",,,,,,
"['Majewski, C. E.', 'Toon, D.', 'Zarringhalam, H.', 'Hopkinson, N.', 'Caine, M. P.']",2020-03-10T17:28:44Z,2020-03-10T17:28:44Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80234', 'http://dx.doi.org/10.26153/tsw/7253']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Rapid Manufacturing,Tailoring the Mechanical Properties of Selective Laser Sintered Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1f3e4d8c-eb3f-47d0-85c3-acfc366c0684/download,,"The ~£1 million IMCRC-funded integrated project ‘Personalised Sports Footwear: From
Elite to High Street’ is investigating the use of Rapid Manufacturing to produce personalised
sports shoes, with the aim of enhancing performance, reducing injury, and providing improved
functionality.
Research has identified that, for sprinting, performance benefits can be achieved by
tuning the bending stiffness of a shoe to the characteristics of an individual athlete. This paper
presents research to date on several novel methods of influencing the mechanical properties of
Selective Laser Sintered shoe soles, with a particular focus on stiffness.",,,,,,
"['Pu, Jing', 'Saleh, Ehab', 'Ashcroft, Ian', 'Jones, Arthur']",2021-11-18T16:35:49Z,2021-11-18T16:35:49Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90419', 'http://dx.doi.org/10.26153/tsw/17340']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacture', 'fused filament fabrication', 'feedstock production', 'continuous carbon fibre PEEK printing', 'composites printing']",Technique for Processing of Continuous Carbon Fibre Reinforced PEEK for Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc46a57a-2b96-45b4-92c3-604f484f6c14/download,University of Texas at Austin,"3D printing of light-weight and mechanically-strong structures facilitates several applications. 3D
printing of continuous carbon fibre reinforced polyetheretherketone (PEEK) presents exciting possibilities as
the high stiffness and strength of the high-performance plastic PEEK reinforced with carbon fibre are paired
with the agility of the 3D printing process. The Fused Filament Fabrication (FFF) process is used to print these
parts, and a pultrusion system was designed and used to produce the filaments since they are not commercially
available. This paper describes the design and construction of a pultrusion system within a wider project on
carbon fibre reinforced PEEK FFF printing. This system is then used to produce the FFF filament with
pultrusion speed and temperature optimisation.",,,,,,
"['Novae, Andrei', 'Kaza, Srinivas', 'Wang, Zetian', 'Lee, CheoI', 'Thomas, Charles']",2018-11-16T16:30:57Z,2018-11-16T16:30:57Z,1996,Mechanical Engineering,doi:10.15781/T21N7Z66R,http://hdl.handle.net/2152/70296,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'plotter cuts', 'manufacturing techniques']",Techniques for Improved Speed and Accuracy in Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bedc8351-f485-42d4-bf33-b5c6e6f0d1c9/download,,"The ability to improve the construction accuracy and/or the build speed for layered
manufacturing techniques is demonstrated using a series of new techniques: (1) Parts can be
decomposed into sections which are constructed in parallel and then assembled. This reduced the
build time and material waste for a sheet foam process. (2) A more accurate interface based on
direct slicing ofthe CAD model can be used to eliminate the need for the intermediary tessellation
file. (3) The layer thickness can be adapted based on the part's geometric complexity to increase
the surface quality, build speed, and z-axis accuracy.",,,,,,
"['Karunakaran, K. P.', 'Pushpa, Vishal', 'Akula, Sreenath Babu', 'Dwivedi, Rajeev', 'Kovacevic, R.']",2020-02-24T14:52:12Z,2020-02-24T14:52:12Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80075', 'http://dx.doi.org/10.26153/tsw/7096']",eng,2005 International Solid Freeform Fabrication Symposium,Open,"['Rapid Prototyping', 'Arc Welding', 'CNC machining']",Techno-Economic Analysis of Hybrid Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/427a809d-63da-40de-9b3b-c061d88d2f48/download,,"Subtractive manufacturing (CNC machining) has high quality of geometric and
material properties but is slow, costly and infeasible in some cases; additive
manufacturing (RP) is just the opposite. Total automation and hence speed is
achieved in RP by compromising on quality. Hybrid Layered Manufacturing
(HLM) developed at IIT Bombay combines the best features of both these
approaches. It uses arc welding for building near-net shapes which are finish
machined to final dimensions. High speed of HLM surpasses all other processes
for tool making by eliminating NC programming and rough machining. The
techno-economic viability of HLM process has been proved through a real life
case study. Time and cost of tool making using HLM promises to be substantially
lower than that of CNC machining and other RP methods. Interestingly, the
material cost in HLM was also found to be lower. HLM is a cheaper retrofitment
to any 3 or 5 axis CNC milling machine or machining center.",,,,,,
"['Haeckel, Felix', 'Meixlsperger, Maximilian', 'Burkert, Torsten']",2021-11-08T22:51:24Z,2021-11-08T22:51:24Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90064', 'http://dx.doi.org/10.26153/tsw/16985']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser beam melting', 'technological challenges', 'part quality', 'automotive series', 'automotive']",Technological Challenges for Automotive Series Production in Laser Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8b370a7a-5fd2-4b40-9810-3a3e67ca081a/download,University of Texas at Austin,"Compared to traditional production methods, Additive Manufacturing enables a tool free
production leading to higher flexibility, freedom of design and lightweight potential. For these
reasons the BMW Group is proceeding from the production of prototypes to the direct series
production of parts.
For metal components, the process of selective Laser Beam Melting is able to realize these
potentials. Aside from the economic issues, technological challenges also have to be met. Among
them is achieving consistent part quality in the production of same parts. To achieve technical
specifications compliant in series production, a defined process stability and reproducibility of
the part properties is needed.
This reproducibility is investigated for the process of selective Laser Beam Melting. Also variables
which have the biggest impact on the part quality throughout a simulated series production are
being examined. Thus the reproducibility of the process can be quantified.
To guarantee a high and stable part quality in the future, approaches are being developed to monitor
or systematically prevent influences, which are found to have a negative effect on the process
quality.",,,,,,
"['Rohde, J.', 'Lindemann, C.F.', 'Jahnke, U.', 'Kruse, A.', 'Koch, R.']",2021-11-08T23:28:50Z,2021-11-08T23:28:50Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90075', 'http://dx.doi.org/10.26153/tsw/16996']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['process chain', 'technology integration', 'additive manufacturing', 'SMEs']",Technology Integration into Existing Companies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b2c0ffe-be7b-4730-b9b0-fad5209e18af/download,University of Texas at Austin,"The implementation of additive manufacturing as an industrial manufacturing process
poses extraordinary challenges to companies due to their far-reaching differences to conventional
processes. In addition to the major differences in the production process, the pre and post process
steps in particular also require a rethinking for companies and their employees. To overcome these
challenges and specifically to assist SMEs in the integration of technologies five industrial
companies are researching together within research project ""OptiAMix"", funded by the German
Federal Ministry of Education and Research (BMBF) and coordinated by the Paderborn University.
This paper focuses on the development of an optimal and standardized process chain and its
implementation in a general integration methodology. This enables the standardized integration of
additive manufacturing in order to create a uniform understanding of the procedures and tasks
within the company for the industrial application of additive manufacturing at an early stage as
well as the full exploitation of its high potentials. Therefore, the methodology also includes other
technology-specific components such as strategic component selection, decision support for ""make
or buy"" and the implementation of automated component marking.",,,,,,
"['Sammons, Patrick', 'Bollineri, Sahit', 'Sibal, Ritika', 'Barton, Kira']",2021-11-04T15:09:06Z,2021-11-04T15:09:06Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/89982', 'http://dx.doi.org/10.26153/tsw/16903']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['process behavior', 'temperature', 'relative humidity', 'electrohydrodynamic jet printing', 'e-jet printing', 'optical adhesives']",Temperature and Humidity Variation Effect on Process Behavior in Electrohydrodynamic Jet Printing of a Class of Optical Adhesives,Conference paper,https://repositories.lib.utexas.edu//bitstreams/db968022-f316-452e-a91e-e9d60f9d0d39/download,University of Texas at Austin,"Electrohydrodynamic jet (e-jet) printing is an emerging additive manufacturing process that
utilizes an electric field to eject material from a micro-/nano-scale microcapillary nozzle. Due to
its contemporary nature and the complex physics which govern the process, little is known about
printing behavior sensitivity with respect to environmental condition variability. The aim of this
work is to construct a systematic experimental design to test and evaluate the relationship between
two environmental variables, temperature and relative humidity, and key process metrics initiating
ejection voltage, printing frequency, and diameter of material ejected. A factorial statistical design
of experiments is used to investigate the parameter space. Results are used to identify temperature
and humidity ranges that give robust printing regimes for a specific class of optical adhesives. Best-fit curves are determined for several of the input-output relationships, which provide a predictive
model for the ink behavior.",,,,,,
"['Keller, Bernd', 'Pfeifer, Rolf', 'Su, Wei-Nien', 'Eyerer, Peter']",2019-02-26T20:18:06Z,2019-02-26T20:18:06Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73495', 'http://dx.doi.org/10.26153/tsw/645']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['PET', 'IR-spectroscopy']",Temperature Dependent Optical Properties of Polymers as a Basis for Laser Process Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d2b73423-75a6-4b4f-a632-d304cc73bc7c/download,,"The knowledge of laser absorption is essential to describe the behavior of polymers in
different laser processes, i.e. SLS, LOM, etc. By means of transmission IR-spectroscopy a
method for measuring temperature dependent penetration depths (absorption length) of polymers,
especially at a wavelength of 10.6Jlm (C02-Laser), is developed. Results for the laser sintering
materials polystyrene (PS), nylon 11 (PA 11), nylon copolymer (CoPA) and polyethylene
terephtalate (PET) are presented. It is detected that the absorption length of polymers will
increase or decrease significantly dependent on temperature. This paper will point out simplified
methods based on the one dimensional heat transfer equation with volume heat source to set the
processing parameters i. e. for the SLS process. The calculations correspond with the measured
data.",,,,,,
"['Josupeit, Stefan', 'Schmid, Hans-Joachim']",2021-10-19T18:26:07Z,2021-10-19T18:26:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89318,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'part cakes', 'temperature distribution', 'temperature history', 'process quality']",Temperature History within Laser Sintered Part Cakes and Its Influence on Process Quality,Conference paper,https://repositories.lib.utexas.edu//bitstreams/aa533013-631f-42d2-b140-6456bb1b5621/download,University of Texas at Austin,"The temperature distribution and history within laser sintered part cakes is an important
aspect regarding the process quality and reproducibility of the polymer laser sintering process.
Especially the temperature history during the build and cooling phase is decisive for powder ageing
effects and the development of part quality characteristics. In this work, a measurement system for
three-dimensional in-process temperature measurements is set up and the influence of different
parameters on the inner part cake temperature distribution and history is analyzed. Important
factors are not only geometrical build job parameters like the part packing density and build height,
but also process parameters like the layer thickness and bulk powder density. Individual in-process
temperature profiles at different positions within a part cake are finally correlated with powder
ageing effects. The results of this work help to understand the temperature history dependency of
powder and part properties and can therefore be used to develop optimized process controls.",,,,,,
"Benda, J.A.",2018-10-03T15:56:18Z,2018-10-03T15:56:18Z,1994,Mechanical Engineering,doi:10.15781/T2W08X194,http://hdl.handle.net/2152/68655,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'stereolithography', 'thermal gradients']",Temperature-Controlled Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d224ae3e-07f4-47e5-b961-383d779bd2eb/download,,"A control scheme for laser sintering has been developed which maintains sintering powder at
constant temperature by actively controlling laser power. It uses a sensor to monitor the
temperature of powder at the focus of a moving laser beam. The control scheme corrects for
variations ofthermal conductivity and powder reflectivity due to the proximity of previously
sintered material, as well as for statistical fluctuations. The sensor also serves as a useful
diagnostic, and is used to confirm model predictions ofthe variation of powder temperature with
process parameters. A second temperature-controlled laser beam, concentric with the first, but of
larger spot size, can be used to locally heat the powder around the sintering powder. This is
shown to reduce curling as well as the balling or agglomeration of molten material",,,,,,
"['Li, C.', 'Liu, J.F.', 'Guo, Y.B.', 'Li, Z.Y.']",2021-10-21T17:12:59Z,2021-10-21T17:12:59Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89409,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'temperature thread', 'distortion', 'multiscale simulation']",A Temperature-Thread Multiscale Modeling Approach for Efficient Prediction of Part Distortion by Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/00ad3a84-82ef-4596-8eae-7150685d25bf/download,University of Texas at Austin,"Selective laser melting (SLM) is a powder bed based additive manufacturing process to
manufacture functional parts. The high-temperature process will produce large tensile residual
stress which leads to part distortion and negatively affect product performance. Due to the
complex process mechanism and coupling multi-physics phenomena, the micro-scale single laser
scan modeling approach is not practical to predict macro part distortion since it demands an
exceedingly long computational time. In this study, a temperature-based multiscale modeling
approach has been developed to simulate material phase transition of powder-liquid-solid for fast
prediction of part distortion. An equivalent body heat flux obtained from the micro-scale laser
scan can be imported as “temperature-thread” to the subsequent layer hatching process. Then the
hatched layer with temperature filed can be used as a basic unit to build up the macro-scale part
with different scanning strategies. The temperature history and residual stress fields during the
SLM process were obtained. In addition, the part distortion can be predicted with a reasonable
accuracy by comparing with the experimental data.",,,,,,
"['Ariadi, Y.', 'Rennie, A.E.W.']",2021-09-23T22:05:21Z,2021-09-23T22:05:21Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88034', 'http://dx.doi.org/10.26153/tsw/14975']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Computer Aided Design', 'design template', 'mass customisation', 'product family architecture', 'Additive Layer Manufacturing']",Templates for Consumer Use in Designing Customised Products,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dc2b6be7-d183-4334-a828-3054ae21c851/download,,"This research proposes a new design system for consumers who would use the
product to run an easy-to-operate design and selection tool by themselves instead of
conventional Computer Aided Design (CAD). In terms of manufacturing the product, several
studies focus on involving the consumer as much and as early as possible. However, recent
developments of Additive Layer Manufacturing (ALM) technologies have led to a renewed
interest in allowing the consumers to develop customised products. As a result,
manufacturing is being brought closer to consumers. This paper would simplify the CAD
stages by utilising design templates for consumer use in customising additive layer
manufactured products.",,,,,,
"['Watanabe, Narumi', 'Shofner, Meisha L.', 'Rosen, David W.']",2021-11-02T19:14:06Z,2021-11-02T19:14:06Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89869,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['polypropylene composites', 'material extrusion', 'additive manufacturing', 'tensile properties', 'process simulation']",Tensile Mechanical Properties of Polypropylene Composites Fabricated by Material Extrusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/09ba610a-27ac-4e19-a479-b1052d569e60/download,University of Texas at Austin,"In the material extrusion additive manufacturing process, a thin filament of material is deposited in
a layer-by-layer manner to fabricate a three dimensional part. The filament deposition pattern can
result in voids and incomplete bonding between adjacent filaments in a part, which leads to reduced
mechanical properties. Further, the layer-by-layer deposition procedure typically results in mechanical
property anisotropy, with higher properties in the layer compared to those across layers. The study
reported in this paper explored various polypropylene composite formulations to address these issues:
low residual stress and warpage, good mechanical properties, and reduced anisotropy. The reduction
in anisotropy will be the focus of this paper as a function of thermal properties and process variable
settings. A series of process simulation models was developed to explore ranges of thermal properties
and process settings, which provided insights into tensile specimen behaviors. Results demonstrate
that anisotropy can be reduced almost completely if the material can be formulated to have low
crystallinity, low coefficient of thermal expansion, and moderate to high thermal conductivity (for a
polymer).",,,,,,
"['Raghavan, S.', 'Soh, N.', 'Hao, L.J.', 'Khan, N.A.', 'Muthu, R.', 'Dzugan, J.']",2021-11-30T20:48:42Z,2021-11-30T20:48:42Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90542', 'http://dx.doi.org/10.26153/tsw/17461']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['tensile property', 'wall thickness', 'maraging steel', 'selective laser melting']",Tensile Property Variation with Wall Thickness in Selective Laser Melted Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e2801b97-99cb-44dd-8af7-16c90859ad41/download,University of Texas at Austin,"3D printed parts with complex geometries have different section thickness which leads to non-uniform
mechanical properties due to microstructure and defect distributions. Hence, it is essential to characterise the
localised mechanical properties to obtain a better understanding of the variability. The tensile property variability
is captured by testing miniature sized tensile coupons that are extracted from different part locations which is
more representative, when compared to testing printed tensile coupons. In the current work a benchmark study
was first carried out to correlate miniature tensile properties with ASTM standard tensile test for different wall
thickness in SLM Maraging steels. Following this, tensile property variation at different locations in an AM
fabricated impeller part was studied. It was observed the thin sections in the part exhibited large variability in the
elongation values. The effect of heat treatment on the tensile properties in the impeller was also studied.",,,,,,
"['Lokhande, Mahendra', 'Crawford, Richard']",2019-10-18T16:46:37Z,2019-10-18T16:46:37Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76257', 'http://dx.doi.org/10.26153/tsw/3346']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Inter-Vertebral,Testing of Compliance in a Prosthetic Socket Fabricated Using Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/030b21dc-1de5-4f18-9e6a-bea613d68a4c/download,,"Solid freeform fabrication techniques offer potential as manufacturing technologies in
applications that require custom design. One such application is the fabrication of prosthetic
sockets. This paper reports on research to manufacture compliant below-the-knee prosthetic
sockets using selective laser sintering (SLS). Compliance in the socket is a critical factor in the
level of comfort the amputee experiences during gait. The ability to control local geometry is
seen as an advantage of SLS in fabricating compliant sockets. This paper presents work on
developing a model of compliance for sockets constructed of Duraform®. The approach taken
here is to provide the necessary compliance by controlling the wall thickness of the socket. To
select the right thickness, a study of the wall deflection with respect to contact pressure was
performed. An experimental testing device was designed and constructed to test the deflection
versus pressure for different thicknesses of test circular discs made of Duraform®. The results
were correlated to a finite element model. These results will be used for designing the
compliance in the walls of prosthetic sockets fitted to actual patients.",,,,,,
"['Garcia, J.P.', 'Camacho, L.A.', 'Hasanyana, A.', 'Espalin, D.']",2024-03-26T22:52:41Z,2024-03-26T22:52:41Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124434', 'https://doi.org/10.26153/tsw/51042']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['big area additive manufacturing', 'BAAM', 'fracture toughness', 'double catilever beam']",TESTING PROTOCOL DEVELOPMENT FOR FRACTURE TOUGHNESS OF PARTS BUILT WITH BIG AREA ADDITIVE MANUFACTURING,Conference paper,https://repositories.lib.utexas.edu//bitstreams/093a83e1-284e-4d17-bd14-ae71d77631dd/download,University of Texas at Austin,"Mechanical testing of additively manufactured parts has largely relied on existing
standards developed for traditional manufacturing. While this approach leverages the investment
made on current standards development, it inaccurately assumes that mechanical response of AM
parts is identical to that of parts manufactured through traditional processes. When considering
thermoplastic, material extrusion AM, differences in response can be attributed to an AM part’s
inherent inhomogeneity caused by porosity, interlayer zones, and surface texture. Additionally,
interlayer bonding of parts printed with large-scale AM is difficult to adequately assess as much
testing is done such that stress is distributed across many layer interfaces; therefore, the lack of
AM-specific standard to assess interlayer bonding is a significant research gap. To quantify
interlayer bonding via fracture toughness, double cantilever beam (DCB) testing has been used
for some AM materials, and DCB has been generally used for a variety of materials including
metal, wood, and laminates. Mode I DCB testing was performed on thermoplastic matrix
composites printed with Big Area Additive Manufacturing (BAAM). Of particular interest was
the crack shape and deflection speed during testing. A modernization of the testing process was
proposed using visual processing of a recording of the crack propagation to get more accurate
calculations. Results discuss the differences when using two crack types and three deflection
speeds.",,,,,,
"['Aman, R.', 'Kitt, A.', 'Corey, Z.', 'Mohr, L.', 'Ruscitto, D.', 'Iyer, N.', 'Rosenberger, B.']",2024-03-26T23:26:43Z,2024-03-26T23:26:43Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124451', 'https://doi.org/10.26153/tsw/51059']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['electron beam directed energy deposition', 'thermal conditions', 'additive manufacturing']",THE EFFECT OF THERMAL CONDITIONS ON PROCESS DEFECTS IN ELECTRON BEAM DIRECTED ENERGY DEPOSITION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/28d1539a-d3ff-45b1-8dc2-33edea957b3f/download,University of Texas at Austin,"Observing process defects at size scales and with sufficient confidence relevant to qualification
efforts has not yet been achieved in metal AM, so non-destructive testing (NDT) techniques are
used to detect porosity within material deposited. NDT costs can be significant and may not
achieve targeted resolution due to geometry and material limitations. In this work, in-process
monitoring of Electron Beam Directed Energy Deposition (EB-DED) is enhanced to include
three thermal history conditions; inter-pass, melt pool superheat and trailing bead temperatures.
Quality scenarios are applied to simulate various process conditions during EB-DED at three
different thermal conditions within production relevant use cases and resultant process defects
are characterized via high throughput computed tomography. Defects are spatially and
temporally registered to process conditions observed during EB-DED and statistically mapped to
thermal scenarios. Thermal condition has a strong influence on the quantity of observed process
defects, with lower interpass temperature resulting in a larger number of defects.",,,,,,
"['Gusain, Rukesh', 'Soeimani Dodaran, Mohammad', 'Gradl, Paul R.', 'Shamsaei, Nima', 'Shao, Shuai']",2024-03-26T16:46:38Z,2024-03-26T16:46:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124368', 'https://doi.org/10.26153/tsw/50976']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'nickel base superalloy', 'y precipitate', 'heat treatment effects', 'tensile properties']",THE INFLUENCE OF HEAT TREATMENTS ON THE MICROSTRUCTURE AND TENSILE PROPERTIES OF ADDITIVELY MANUFACTURED INCONEL 939,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b005bfa1-7c35-42c8-a294-952bd3197093/download,University of Texas at Austin,"This study investigated the effect of heat treatment variations on the microstructure and tensile
properties of laser powder bed fused Inconel 939. Three different heat treatment schedules, all of which
comprise stress relief, hot isostatic pressing, solution annealing, and aging, were followed, and resulting changes
in microstructure were analyzed using scanning electron microscopy. Tensile tests were conducted on
specimens subjected to different heat treatments to evaluate the mechanical properties at room temperature.
Microstructural results showed that solution treatment at 1190 °C for 4 h led to better removal of dendritic
microstructure, while second-step aging at 850 °C resulted in monomodal distribution of precipitates.
However, the second-step aging temperatures from 750 to 800 °C resulted in bi-modal distribution. The
optimal heat treatment schedule, which yielded a superior combination of strength and ductility, involved
solution treatment at 1190 °C for 4 h and two-step aging at 1000 °C for 6 h and 800 °C for 4 h.",,,,,,
"['Petersen, Haley E.', 'Sampson, Brad J.', 'Failla, David P.', 'Priddy, Matthew W.', 'McClelland, Zackery B.']",2024-03-26T16:49:30Z,2024-03-26T16:49:30Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124369', 'https://doi.org/10.26153/tsw/50977']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['maraging 300 steel', 'M300', 'laser powder bed fusion', 'L-PBF', 'additive manufacturing']",The Variation of Mechanical Properties of M300 Maraging Steel Manufactured with Varying Process Parameters in Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f9c67ae4-11cd-48ea-8684-66be7c9408bf/download,University of Texas at Austin,"Laser power bed fusion (L-PBF) is a type of additive manufacturing (AM) that uses layers
of powdered metal and a laser to manufacture a part in a layer-by-layer fashion. L-PBF uses a
variety of process parameters that ultimately determine the overall quality and mechanical
properties of a print. The ability to alter parameters allows for the utilization of various metals in
this form of AM. Maraging 300 steel (M300) is a material of particular interest due to its combined
tensile strength and high strength-to-weight ratio. By using an assortment of parameters and
comparing the resulting mechanical properties it can be determined which process parameters
result in a more favorable part to be used in a variety of applications. A favorable process parameter
set was selected for future use. This study aims to determine which process parameters result in
the best overall mechanical properties of M300 manufactured using L-PBF.",,,,,,
"['Bzymek, Zbigniew M.', 'Shaw, Leon L.', 'Marks, Wojciech']",2019-02-22T20:12:44Z,2019-02-22T20:12:44Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73474', 'http://dx.doi.org/10.26153/tsw/624']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'SALD']",A Theoretical Model for Optimization of SALD Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0dbcdd8e-189f-45a0-ad9c-2a9b333ba558/download,,"This paper addresses the need to conduct theoretical work concerning an economical way
of Solid Freeform Fabrication rendering by using selective Area Laser Deposition (SALD). The
part in SALD rendering process is formed layer by layer that, in turn, is composed of stripes of
material produced in the path of a laser. There are three situations in which such a stripe can be
rendered: a) alone, b) with one neighbor on one side, and c) with neighbors on both sides.
Residual thermal stresses in the part are expected to be affected by how a stripe is rendered.
Furthermore, the residual thermal stress and the mechanical property of the part are also dictated
by other processing variables such as laser scanning patters, laser input power, scanning speed,
scanning spacing, deposition temperature, gas precursor pressure, intrinsic thermal conductivity
and mechanical properties of the rendered material. A theoretical approach is proposed to address
the minimization of residual thermal stresses and rendering times and the maximization of the
strength of the part. It is proposed that such multiple optimizations that are dictated by many
decision variables can be solved by minimizing and/or maximizing object functions dePending on
the design criteria for each attribute of the rendered part",,,,,,
"['Wu, Tao', 'Das, Suman']",2021-10-06T21:25:02Z,2021-10-06T21:25:02Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88449', 'http://dx.doi.org/10.26153/tsw/15386']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['large area maskless photopolymerization', 'part stresses', 'part warpage', 'crack development']",Theoretical Modeling and Experimental Characterization of Stress Development in Parts Manufactured Through Large Area Maskless Photopolymerization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ce4943a-aa1e-4fe2-8d22-df35f96df77d/download,University of Texas at Austin,"This paper aims at investigating the evolution of stresses in parts manufactured through
large area maskless photopolymerization (LAMP). A theoretical model was established to
understand the curing process for LAMP and a finite element analysis was performed to model
the dynamic evolution of stresses during the layer-by-layer fabrication process using Abaqus
software. This model serves to suggest strategies for reducing stresses, part warpage, and crack
development in parts made through LAMP.",,,,,,
"['Wang, Yu', 'Chen, Ziqian', 'Li, Houqi', 'Li, Shuaishuai']",2021-11-15T21:48:05Z,2021-11-15T21:48:05Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90281', 'http://dx.doi.org/10.26153/tsw/17202']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'material extrusion', 'mechanical performance', 'anisotropy', 'force-flow']",Theory and Methodology for High-Performance Material-Extrusion Additive Manufacturing Under the Guidance of Force-Flow,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bf11333b-d8f3-4ec2-8a2d-3c03dba5cb96/download,University of Texas at Austin,"Anisotropy on strength between different layers and filaments in the material extrusion
(MEX) process has a significant influence on mechanical performances of fabricated objects. A
novel theory and methodology is proposed to improve mechanical performances of parts by
designing and controlling the anisotropy. Anisotropy can then be in alignment with load paths
under the guidance of force-flow. In this study, by (1) dividing the part into several building areas
and generating corresponding building direction considering the force-flow properties of the part;
(2) generating novel toolpaths which are based on principal stress lines (PSL) and will map the
direction and magnitude of PSL, the adverse influence of anisotropy on mechanical performances
between different layers and filaments can be minimized respectively. A 6-axis robot arm
integrated with an extrusion system is constructed to handle the multi-direction building of each
building area. The study will advance the development of additive manufacturing from ""prototype""
to ""end-use"".",,,,,,
"['Maxwell, James L.', 'Pegna, Joseph']",2018-05-03T19:29:02Z,2018-05-03T19:29:02Z,1993,Mechanical Engineering,doi:10.15781/T2DF6KM4K,http://hdl.handle.net/2152/65065,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['LCVD', 'SALD', 'Microfrabrication', 'selective area laser deposition']",Thermal Analysis and Modeling of Steady-State Rod Growth During Gas-Phase Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1be7ec8c-00d4-4851-91af-c2756dea884b/download,,"An analysis ofthe steady-state growth ofrods during gas-phase solidfreeform fabrication
is presented. It is demonstrated that heat transfer controls the evolution ofshape during laser-induced
pyrolysis of slender 3-D structures. Insulating and conductive deposit materials were studied, using
both simple analytic and numerical simulations to demonstrate how steady-state rod growth is
achieved.",,,,,,
"['Mohammadizadeh, M.', 'Fidan, I.']",2021-11-18T02:00:30Z,2021-11-18T02:00:30Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90405', 'http://dx.doi.org/10.26153/tsw/17326']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fiber reinforcement', 'mechanical properties']",Thermal Analysis of 3D Printed Continuous Fiber Reinforced Thermoplastic Polymers for Automotive Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fae3e550-7d1f-46ed-8e9b-c2a87ab2e073/download,University of Texas at Austin,"Continuous fiber reinforced additive manufacturing (CFRAM) is a five-year old manufacturing
technology with a wide range of potential applications. CFRAM benefits from the advantages of
Fused Filament Fabrication as fast and low cost production of complicated structures, while fiber
reinforcement improves thermomechanical properties. CFRAM provides wide range of potential
applications in auto industry, aerospace, sport goods and medical tools to replace metals and
conventional composites with CFRAM parts. The notable attention toward CFRAM technology
justifies the need for investigation of thermomechanical properties of printed components. In this
study, CFRAM components were manufactured using Markforged 3D-printer. Nylon was used
as thermoplastic polymer matrix and carbon fiber (CF), fiber glass (FG), and Kevlar as
reinforcing agents. Thermo-Gravimetric Analysis (TGA), and Dynamic Mechanical Analysis
(DMA) measurements were conducted to investigate thermomechanical properties. The results
of this study will be a milestone for applications of CFRAM components for automotive
industry.",,,,,,
"['AtifYardimci, M.', 'Hattori, Takeshi', 'Guceri, Selcuk I.', 'Danforth, Stephen C.']",2018-12-07T16:28:14Z,2018-12-07T16:28:14Z,1997,Mechanical Engineering,doi:10.15781/T2M61C92N,http://hdl.handle.net/2152/71449,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition process', 'discrete layers']",Thermal Analysis Of Fused Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0661da81-51b6-4b14-baf8-2a3f736eea27/download,,"Fused Deposition processes involve successive melting, extrusion and solidification of
thermoplastic polymer melts. Fluid mechanics and heat transfer of neat or particle-filled
polymeric melts, viscoelastic deformation and solidification ofthe roads that are being produced,
and repetitive thermal loading of the growing part are important physical processes that control
the final quality of the part. Previous computational process models investigated deposition and
cooling processes for single and multiple filaments. In the current study, complimentary
computational models are presented for the extrusion phase of the process. Impact of liquefier
and nozzle design on thermal hardware behavior and operational stability has been quantified.
Also a detailed study of temperature field near the vicinity of deposition point is presented with
particular emphasis on dimensional analysis and deposition ofmultiple material systems.",,,,,,
"['Billah, Kazi Md Masum', 'Lorenzana, Fernando A.R.', 'Martinez, Nikki L.', 'Chacon, Sarah', 'Wicker, Ryan B.', 'Espalin, David']",2021-11-18T01:58:51Z,2021-11-18T01:58:51Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90404', 'http://dx.doi.org/10.26153/tsw/17325']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['thermal analysis', 'neat ABS', 'reinforced ABS', 'carbon fiber', 'thermoplastics', 'large area 3D printing']",Thermal Analysis of Thermoplastic Materials Filled with Chopped Fiber for Large Area 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2ea51c57-2172-4142-9f4e-db2d1df20973/download,University of Texas at Austin,"At room temperature, material extrusion, in the context of large area fabrication, requires
thermally stable materials and, as a result, fillers are included to tailor the thermal behavior. This
research investigated the thermophysical properties of neat ABS and short carbon fiber (CF)
reinforced ABS. Thermogravimetric analysis, differential scanning calorimetry, and
thermomechanical analysis were carried out to determine the thermophysical properties. The
addition of CF (20 wt. %) to an ABS matrix caused the glass transition temperature to change
slightly (110 °C to 105 °C). Also, the CF within the ABS matrix reduced the thermal stability by
decreasing the degradation on set temperature by (323 °C to 253 °C). Thermal deformation
analysis showed that large area pellet extruded AM machine produces highly anisotropic materials.
Thermomechanical analysis results showed that the coefficient of thermal expansion (CTE)
reduced 4 times in the perpendicular to the extruded direction. The dataset and knowledge from
the thermal analysis can be useful to design optimized printing parameters for highly filled
thermoplastics used in large area 3D printing machines.",,,,,,
"['Dai, K.', 'Shaw, L.']",2019-10-18T15:20:02Z,2019-10-18T15:20:02Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76236', 'http://dx.doi.org/10.26153/tsw/3325']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Fabrication,Thermal and Stress Modeling of Laser Fabrication of Multiple Material Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/35f85c04-7e22-463a-8333-387636fda758/download,,"Solid freeform fabrication (SFF) is an automated manufacturing process that builds threedimensional complex-shaped structures layer-by-layer directly from CAD data without partspecific tooling and human intervention. In many cases multiple materials are involved in
fabricating one component using SFF approaches. Porcelain-fused-to-metal (PFM) restoration
for permanent fixed prosthodontics is an example of this kind. In this study 3-dimensional finite
element modeling has been carried out to investigate the temperature and stress field in
processing of multiple material components using a moving laser beam. Effects of fabrication
sequences, laser scanning patterns and scanning rates on residual stresses have been investigated.
Implications of these results on laser fabrication of multiple materials have been discussed.",,,,,,
"['Velu, Rajkumar', 'Singamneni, Sarat']",2021-10-21T21:58:09Z,2021-10-21T21:58:09Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89453,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['PMMA+β-TCP', 'biopolymer composites', 'selective laser sintering', 'thermal fields']",Thermal Aspects of Selective Laser Sintering of PMMA+β-TCP Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9280775-1222-47b3-8f22-c2707d782f57/download,University of Texas at Austin,"Biocompatible and osteoconductive characteristics expected of materials used for bone grafting
applications identified Polymethyl methacrylate (PMMA) and β-Tri Calcium Phosphate (βTCP) combinations to be potential biopolymer composite options. Together with additive
manufacturing methods such as selective laser sintering (SLS), these materials options would
also bring about the benefits of free from fabrication. While earlier research laser sintering
PMMA+β-TCP composites experimentally proved the combination to be promising, the
resulting microstructures are indicative of varied coalescence and consolidation with varying
amounts of β-TCP. Considering the differential thermal properties, it becomes necessary and
interesting to evaluate the possible role of the filler material in altering the nature of the thermal
fields. This paper presents results of numerical and experimental work carried out investigating
the thermal fields of laser sintered PMMA+β-TCP composites.",,,,,,
"['Griffith, M.', 'Schlienger, M. E.', 'Harwell, L. D.', 'Oliver, M. S.', 'Baldwin, M. D.', 'Ensz, M. T.', 'Smugeresky, J. E.', 'Essien, M.', 'Brooks, J.', 'Robino, C. V.', 'Hofineister, W. H.', 'Wert, M. J.', 'Nelson, D. V.']",2019-02-19T17:22:15Z,2019-02-19T17:22:15Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73432', 'http://dx.doi.org/10.26153/tsw/584']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['H13 Tool Steel', 'LENS']",Thermal Behavior in the Lens Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ee8ad82-ed3c-4639-b361-ea5d194e4458/download,,"Direct laser metal deposition processing is a promising manufacturing technology which
could significantly impact the length oftime between initial concept and finished part. For
adoption ofthis technology in the manufacturing environment, further understanding is required
to ensure robust components with appropriate properties are routinelyfabricated. This requires a
complete understanding ofthe thermal history.during part fabrication and control ofthis behavior.
This paper will describe our research to understand the thermal behavior for the Laser Engineered
Net Shaping (LENS) process!, where a component is fabricated by focusing a laser beam onto a
substrate to create a molten pool in which powder particles are simultaneously injected to build
each layer. The substrate is moved beneath the l~ser beam to deposit a thin cross section, thereby
creating the desired geometry for each layer. After deposition of each layer, the powder delivery
nozzle and focusing lens assembly is incremented in the positive Z-direction, thereby building a
three dimensional component layer additively.
It is important to control the thermal behavior to reproducibly fabricate parts. The
ultimate intent is to monitor the thermal signatures and to incorporate sensors and feedback
algorithms to control part fabrication. With appropriate control, the geometric properties
(accuracy, surface finish, low warpage) as well as the materials' properties (e.g. strength,
ductility) of a component can be dialed into the part through the fabrication parameters. Thermal
monitoring techniques will be described, and their particular benefits highlighted. Preliminary
details in correlating thermal behavior with processing results will be discussed.",,,,,,
"['Karapatis, N. P.', 'Guidoux, Y.', 'Gygax, P. E.', 'Glardon, R.']",2019-02-19T17:04:49Z,2019-02-19T17:04:49Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73431', 'http://dx.doi.org/10.26153/tsw/583']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'metallic powders']",Thermal Behavior of Parts Made by Direct Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ae91c4f-2259-4e0d-9aca-b2cc0ef4b381/download,,"The Direct Metal Laser Sintering (DMLS) manufacturing technique induces thermal stresses
in parts. When such parts are used at elevated temperatures, residual stresses are relaxed and the
part can suffer significant distortion. This study presents values of geometrical distortion for two
laser exposure strategies and for different heat treatment temperatures and durations. Surface and
bulk hardness data are provided as well as porosity measurements. At temperatures above 300
the geometrical changes become important. A stabilization treatment. at 600°C can help reduce
distortions.",,,,,,
"['Yuan, Mengqi', 'Bourell, David', 'Diller, Tim']",2021-10-05T13:28:24Z,2021-10-05T13:28:24Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88366', 'http://dx.doi.org/10.26153/tsw/15305']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'thermal conductivity', 'thermal diffusivity', 'polyamide 12']",Thermal Conductivity Measurements of Polyamide 12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a3fa6b85-1651-4dbc-8500-8487ab22823a/download,University of Texas at Austin,"An important component in understanding the laser sintering process is knowledge of the
thermal properties of the processed material. Thermal conductivity measurements of pure
polyamide 12 were conducted based on transient plane source technology using a Hot Disk®
TPS500 conductivity measurement device. Polyamide samples were packed to three different
densities in nitrogen at steady state. Thermal diffusivity and conductivity were measured from
40°C to 170°C for both fresh powder and previously heated (“recycled”) powder. The fresh
powder tests revealed that thermal conductivity increased linearly with temperature while for
previously heated powder, more constant and higher thermal conductivity was observed as it
formed a powder cake. Tests were also performed on fully dense polyamide 12 to establish a
baseline. Polyamide 12 powder had a room-temperature thermal conductivity of
approximately 0.1 W/mK which increased with temperature, whereas the bulk laser sintered
polyamide 12 room-temperature value was 0.26 W/mK and generally decreased with
increasing temperature.",,,,,,
"['Orme, Melissa E.', 'Huang, Changzheng']",2018-10-04T20:35:09Z,2018-10-04T20:35:09Z,1995,Mechanical Engineering,doi:10.15781/T2RX93Z5T,http://hdl.handle.net/2152/68710,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'Solid free-form fabrication', 'metallic structural components']",Thermal Design Parameters Critical to the Development of Solid Freeform Fabrication of Structural Materials with Controlled Nano-liter Droplets,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5b38decf-ec13-4a77-a14b-6a28506a806c/download,,,,,,,,
"['Norrell, Jeffery L.', 'Wood, Kristin L.', 'Crawford, Richard H.']",2019-03-12T16:58:50Z,2019-03-12T16:58:50Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73603', 'http://dx.doi.org/10.26153/tsw/745']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'in-bed structures']",Thermal Effects of In-Bed Rapid Prototyping Metastructures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4060cbc0-9615-4fe6-9acf-8623f708663b/download,,"Iuan effort. t.o produce higher quality Selective Laser Sint.ering (SLS) parts, a number of approaches
have been taken. One such approach is t.he use of in-bed·metastructures, such as tortillas and canist.ers. In past. work, these metast.ructures have produced changes part qualit.y, but only qualitative
analysis has been done. Using a model created during previous work, a numerical st.udy of these in-bed
metastructures is undertaken, with the goal of systematically determining the thermal effectiveness of the
various structures. The thermal behavior of in-bed st.ructures subjected t.o mixed mode convection and
conduction is then determined. Result.s demonstrate that in-bed structures can be designed t.o spatially
affectin-bed thermal transfer, providing SLS users t.he capability to remove or retain heat as a part's
local geometry demands.",,,,,,
"['Hopkinson, Neil', 'Dickens, Phill']",2018-11-30T15:29:29Z,2018-11-30T15:29:29Z,1997,Mechanical Engineering,doi:10.15781/T2V40KK0V,http://hdl.handle.net/2152/70594,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['3DKeltool', 'EDM']",Thermal Effects on Accuracy in the 3DKeltool™ Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f447be80-cc6b-46f5-a505-dd5c368dca94/download,,"The 3DKeltool™ process has been used to produce injection moulding inserts capable
ofproducing millions ofparts with quick cycle times (1). Short lead times are possible
however accuracy is reduced for dimensions over 150mm.
The use ofroom temperature vulcanising (RTV) silicone rubber in the 3DKeltool™
process is a possible reason for the loss of accuracy in larger parts. Effects of
temperature changes during the process are assessed both theoretically and
experimentally.
The results show close agreement between theoretical predictions and experimental
results for dimensional changes. Suggestions which could allow accurate manufacture
oflarger 3DKletool™ parts are presented.",,,,,,
"['Taylor, Samantha', 'Beaman, Joseph', 'Fish, Scott']",2021-11-04T13:36:02Z,2021-11-04T13:36:02Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89955,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['mechanical property', 'correlation', 'in-situ monitoring', 'thermal history', 'selective laser sintering']",Thermal History Correlation with Mechanical Properties for Polymer Selective Laser Sintering (SLS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/b53aad8c-e440-4be6-9a6b-198a76398aed/download,University of Texas at Austin,"This study investigates the in-situ monitoring of the Selective Laser Sintering (SLS)
process by focusing on finding correlations between tensile strength, elongation to break, and
fracture location to the observed thermal history of manufactured parts. It compared the
monitoring ability of a stationary reference mid-wave infrared and a bore-sighted mid-wave
infrared camera. ZYX tensile bars were built to leverage the high dependence of tensile strength
on interlayer bonding, which is generally assumed to be related to layerwise thermal conditions.
Various thermal history analysis methods, for example: cold subregion temperature, average
layer temperature, and outline average temperature were tested. Additionally, several smoothing
techniques that reduced noise over time were assessed for their ability to improve the correlation
for each individual method. Overall, cold subregions observed over four layers in a tensile bar’s
thermal history had the best correlation with fracture location and mechanical strength.",,,,,,
"['Flach, Lawrance', 'Klostennan, Donald A.', 'Chartoff, Richard P.']",2018-12-07T16:25:26Z,2018-12-07T16:25:26Z,1997,Mechanical Engineering,doi:10.15781/T2QZ2336G,http://hdl.handle.net/2152/71448,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['LOM', 'experimental materials']",A Thermal Model For Laminated Object Manufacturing (LOM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/a5936987-0589-476c-b990-64086d3827aa/download,,"A thennal model for Laminated Object Manufacturing (LOM) has been developed. The
model is based on 3-dimensional transient heat conduction in a rectangular geometry LOM part.
Heat transfer from the heated roller to the laminated part as well as heat loss to the surroundings
and the base plate are considered. It allows calculation of the transient temperature distribution
within the part during the application of a new layer as well as during other periods of the LOM
build cycle. To verify the model performance, thennocouples were embedded every 4th layer in a
20-layer ceramic part while it was being built on a standard LOM-2030. The model predictions are
in excellent agreement with the measured temperature profiles. In addition to explaining the
observed thennal behavior ofLOM parts, model predictions also have direct application to on-line
control ofthe part temperature during the build process, to be discussed herein.",,,,,,
"['Diller, Timothy T.', 'Sreenivasan, Rameshwar', 'Beaman, Joseph', 'Bourell, David', 'LaRocco, Janna']",2021-09-30T18:50:39Z,2021-09-30T18:50:39Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88277', 'http://dx.doi.org/10.26153/tsw/15218']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['thermal control', 'selective laser sintering', 'surface finish', 'nylon parts', 'polyamide parts', 'thermal diffusivity']",Thermal Model of the Build Environment for Polyamide Powder Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7c9fd931-5afb-410f-ac8a-6246340a65ca/download,University of Texas at Austin,"Precise thermal control of selective laser sintering
(SLS) is desirable for improving geometric accuracy,
mechanical properties, and surface finish of nylon, or
polyamide (PA) parts. A modeling and measurement
system was set up to facilitate development of thermal control strategies to improve these characteristics. A SinterStation 2500 SLS machine was used as
a test machine for studying builds of parts made of
DuraformTM PM nylon powder. Internal temperature measurements of the process were made using
resistance temperature detectors (RTDs) embedded
in the part bed powder. Surface temperature was
measured with an infra-red camera aimed through
the front window. A macro-scale time-dependent
thermal numerical model of the build chamber and
powder bins was developed as a means of evaluating
temperature control of the build process. By comparing the measured and predicted temperature profiles,
various estimates of the thermal diffusivity of the nylon powder were evaluated.",,,,,,
"['Wang, Liang', 'Felicelli, Sergio D.', 'Craig, James E.']",2020-03-09T13:46:16Z,2020-03-09T13:46:16Z,8/23/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80178', 'http://dx.doi.org/10.26153/tsw/7197']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Laser Engineered Net Shaping,Thermal Modeling and Experimental Validation in the LENS™ Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f8a28d1d-dc92-4cb3-bc91-0ef01b9af3a0/download,,"Several aspects of the thermal behavior of deposited stainless steel 410 (SS410) during the
Laser Engineered Net Shaping (LENSTM) process were investigated experimentally and
numerically. Thermal images in the molten pool and surrounding area were recorded using a
two-wavelength imaging pyrometer system, and analyzed using ThermaVizTM software to obtain
the temperature distribution. The molten pool size, temperature gradient, and cooling rate were
obtained from the recorded history of temperature profiles. The dynamic shape of the molten
pool, including the pool size in both travel direction and depth direction, was investigated and
the effect of different process parameters was illustrated. The thermal experiments were
performed in a LENSTM 850 machine with a 3kW IPG laser for different process parameters. A
three-dimensional finite element model was developed to calculate the temperature distribution
in the LENS process as a function of time and process parameters. The modeling results showed
good agreement with the experimental data.",,,,,,
"['Li, Lan', 'Lough, Cody', 'Replogle, Adriane', 'Bristow, Doug', 'Landers, Robert', 'Kinzel, Edward']",2021-11-03T20:46:55Z,2021-11-03T20:46:55Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89929,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['thermal modeling', '304L stainless steel', '304L', 'selective laser melting', 'Abaqus']",Thermal Modeling of 304L Stainless Steel Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eee54541-eef5-482f-aebe-7e6925686df1/download,University of Texas at Austin,"This paper describes the continuum thermal modeling of the Selective Laser Melting
(SLM) process for 304L stainless steel using Abaqus. Temperature dependent thermal properties
are obtained from literature and incorporated into the model capturing the change from powder to
fully dense stainless steel. The thermal model predicts the temperature history for multi-track scans
under different process parameters (laser power, effective scanning speed, hatch spacing) which is
used to extract the melt-pool size, solidification rate, and temperature gradients. These are
compared to experimental results obtained from a Renishaw AM250 in terms of the melt pool size,
grain structure, and cell spacing. These experimental results are used to tune unknown simulation
parameters required by the continuum model including the optical penetration depth and thermal
conductivity multiplier for the molten region. This allows the model to yield predictive simulations
of melt pool size and solidification structure of SLM 304L stainless steel.",,,,,,
"['Snider, Elias', 'Gegel, Michelle', 'Holguin, Ryan', 'Dominguez, Cesar', 'Bernardin, John', 'Bristow, Douglas', 'Landers, Robert']",2021-12-07T17:23:13Z,2021-12-07T17:23:13Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90728', 'http://dx.doi.org/10.26153/tsw/17647']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['thermal modeling', 'optical fibers', 'design parameters', 'metal additive manufacturing']",Thermal Modeling of Fiber Optic Embedment in Metal Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0f44a561-4fbf-478d-9444-597f2bc2df0d/download,University of Texas at Austin,"Optical fibers are useful in many sensing applications, including temperature and
radiation sensing as well as distributed strain measurements. These optical fibers may be
consolidated within an additive manufacturing process to help diagnose and/or monitor the
mechanical performance of a part. However, bonding optical fibers to metal parts using laser-based additive manufacturing requires processing temperatures dangerous to the fiber, posing
challenges for fiber survival. To protect the fiber and allow bonding with the metal part, the
fibers are plated with a nickel coating prior to embedment – a process that is costly to perform.
These coatings may also have small internal defects that vary from one fiber to the next. Due to
manufacturing cost and lack of repeatability, it is difficult to experimentally determine
appropriate process parameters, such as laser power and coating thickness. Thus, numerical
modeling offers an efficient approach to exploring embedment parameters and their effect on
fiber survivability. This work employs transient thermal models of embedment processes to
identify and simulate significant design parameters such as coating thickness, embedment
geometry, and cooling time. A transient thermal simulation was developed and is presented
which models fiber optic embedment processes via Laser Engineered Net Shaping (LENS®, a
blown powder, direct energy deposition process) and trends in peak fiber core temperatures, as
well as thermal shock are discussed.",,,,,,
"['Chen, Tiebing', 'Zhang, Yuwen']",2020-02-21T21:44:15Z,2020-02-21T21:44:15Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80073', 'http://dx.doi.org/10.26153/tsw/7094']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Thermal Modeling of Metal Powder-Based Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/83bf1855-72d8-4212-aa5a-e4af16755ac7/download,,"In order to get a better understanding of Selective Laser Sintering (SLS) process of the metal
powders, three-dimensional modeling of laser sintering of a metal powder mixture that contains
two kinds of metal powder with significantly different melting points under a moving Gaussian
laser beam is investigated numerically. Laser induced melting and resolidification accompanied
by shrinkage are modeled using a temperature transforming model. The liquid flow of the melted
low melting point metal driven by capillary and gravity forces is also included in the physical
model. Both complete and partial shrinkages are considered in the model. Simulations are
performed for both single line laser scanning and multiple-line laser scanning. The numerical
results are compared with experimental results and a detailed parametric study is performed. The
effects of the moving heat source intensity, the scanning velocity, the thickness of the powder
layer and the number of existing sintered layers underneath on the sintering depth, the shape of
the heat affected zone (HAZ) and the temperature distribution are discussed. The optimized
dimensionless moving heat source intensity increases with increasing scanning velocity in order
to achieve the desired sintering depth and bond the newly sintered layer to the previously
sintered layers.",,,,,,
"['Boillat, Eric', 'Glardon, Rémy', 'Matthey, Marc']",2020-02-17T14:58:27Z,2020-02-17T14:58:27Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/80003', 'http://dx.doi.org/10.26153/tsw/7028']",eng,2004 International Solid Freeform Fabrication Symposium,Open,"['Layered Manufacturing Techniques', 'Optimization', 'Cooling']",Thermal Optimization of Injection Molds Produced by Layered Manufacturing Techniques,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ffe72365-3678-4d81-8280-74172f8775b1/download,,"Producing injection tooling with cooling channels of almost any form seems to be one of the most
promising advantages of Layered Manufacturing Techniques (like Selective Laser Sintering). It could
be efficiently exploited to achieve higher productivity or better quality parts in injection molding.
Unfortunately, at the present time, the lack of data-processing tools to design optimal cooling systems
still prevents us from fully benefiting from this new potential.
The first objective of this paper is to present a methodology for the optimal design of cooling systems
in three-dimensional injection molds. Our optimization process is based on a finite element model of
the mold and on the standard gradient method.
In the second part of this paper, we compare a conventional mold and a mold equipped with a cooling
system optimized by means of the proposed methodology. The comparison is carried out thanks to
an appropriate protocol. The conclusion is that the optimization of the cooling system doubled the
productivity of the mold.",,,,,,
"['Monroe, J.G.', 'Ibrahim, O.T.', 'Thompson, S.M.', 'Shamsaei, N.', 'Bian, L.', 'Elwany, A.']",2021-10-21T21:51:17Z,2021-10-21T21:51:17Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89451,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'flat-plate oscillating heat pipe', 'FP-OHP', 'titanium alloy', 'Ti-6Al-4V']",Thermal Performance and Surface Characterization of a Selective Laser Melted Flat-Plate Oscillating Heat Pipe,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fed01271-13dc-4b42-8527-dce3bf57d9e3/download,University of Texas at Austin,"A titanium alloy (Ti-6Al-4V) flat-plate oscillating heat pipe (FP-OHP) was fabricated
using Selective Laser Melting (SLM). The 50.8 x 38.1 x 15.75 mm3
FP-OHP consisted of four
integral layers of capillary-sized, circular mini-channels (1.52 mm in diameter). The post-SLM
prototype was de-powdered using pressurized air and a novel layer-by-layer, plug-and-pressurize
design/approach. A vacuum-grade port was threaded into the FP-OHP, and the heat pipe was
charged with acetone (~70% by volume) then hermetically sealed. Experiments were conducted
to characterize the thermal performance and functionality of the multi-layered FP-OHP. Results
indicate that the acetone-filled FP-OHP operates and can provide for an 800% increase in
effective thermal conductivity relative to pure Ti-6Al-4V. The build integrity of the FP-OHP was
investigated by shearing along its width to inspect the channel-area surface using field emission
scanning electron microscopy (SEM) and laser triangulation for channel topography. The mean
surface roughness was found to be approximately 45 micrometers and characterized by partiallymelted, abraded particles. This study demonstrates the appeal of additive manufacturing for
fabrication of customized heat transfer media traditionally challenging to realize.",,,,,,
"['Bontha, Srikanth', 'Klingbeil, Nathan W.']",2019-11-20T16:24:50Z,2019-11-20T16:24:50Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78472', 'http://dx.doi.org/10.26153/tsw/5557']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Thermal Process,Thermal Process Maps for Controlling Microstructure in Laser-Based Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0220de9f-dde6-4852-b868-2bc957a8a43a/download,,"The ability to predict and control microstructure in laser deposited materials requires an
understanding of the thermal conditions at the onset of solidification. The focus of this work is
the development of thermal process maps relating solidification cooling rate and thermal gradient
(the key parameters controlling microstructure) to laser deposition process variables (laser power
and velocity). The approach employs the well-known Rosenthal solution for a moving point heat
source traversing an infinite substrate. Cooling rates and thermal gradients at the onset of
solidification are numerically extracted from the Rosenthal solution throughout the depth of the
melt pool, and dimensionless process maps are presented for both thin-wall (2-D) and bulky (3-
D) geometries. In addition, results for both small-scale (LENSTM) and large-scale (higher power)
processes are plotted on solidification maps for predicting grain morphology in Ti-6Al-4V.
Although the Rosenthal results neglect temperature-dependent properties and latent heat effects,
a comparison with 2-D FEM results over a range of LENSTM process variables suggests that they
can provide reasonable estimates of trends in solidification microstructure. The results of this
work suggest that changes in process variables could potentially result in a grading of the
microstructure (both grain size and morphology) throughout the depth of the deposit, and that the
size-scale of the laser deposition process is important.",,,,,,
"['Carter, William', 'Masuo, Christopher', 'Nycz, Andrzej', 'Noakes, Mark', 'Vaughan, Derek']",2021-11-30T19:24:28Z,2021-11-30T19:24:28Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90520', 'http://dx.doi.org/10.26153/tsw/17439']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['wire-arc additive manufacturing', 'thermal imaging', 'process monitoring', 'IR camera', 'MIG']",Thermal Process Monitoring for Wire-Arc Additive Manufacturing using IR Cameras,Conference paper,https://repositories.lib.utexas.edu//bitstreams/51f7751a-ffe1-4a46-89d2-d5ab365acbda/download,University of Texas at Austin,"Wire-arc additive manufacturing systems use robotic MIG welders to build parts using
welding wire. As a part is built the temperature rises as energy is input and the thermal mass
increases. While some pre-heat is ideal for welding, improper thermal management can lead to
defects and negatively affect material properties. Thermal imaging allows for non-contact
thermal monitoring and can be used to track thermal gradients as well as layer temperatures
before and after deposition providing a method to ensure proper thermal management. A typical
IR camera setup on an mBAAM system is discussed along with methods to use thermal
monitoring to improve material properties and reduce defects in the final part.",,,,,,
"['Xue, Samuel', 'Barlow, J.W.']",2018-04-12T17:26:40Z,2018-04-12T17:26:40Z,1990,Mechanical Engineering,doi:10.15781/T2736MK0M,http://hdl.handle.net/2152/64271,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Chemical Engineering Department', 'thermal conductivities', 'differential scanning calorimetry']",Thermal Properties of Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4eed7f4f-e749-46d5-a1dc-21145f2c1488/download,,"This paper presents measurements of the specific heats of various powders, including nylon,
ABS, PVC, and two kinds of wax. An unsteady-state conduction technique is also presented for
measuring the thermal conductivities of these powders at temperatures below those where sintering
occurs. Both specific heats and thermal conductivities are found to be functions of temperature.",,,,,,
"['Whiting, J.', 'Lane, B.', 'Chou, K.', 'Cheng, B.']",2021-11-02T13:32:55Z,2021-11-02T13:32:55Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89797,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'thermal properties', 'thermal diffusivity', 'thermal conductivity']",Thermal Property Measurement Methods and Analysis for Additive Manufacturing Solids and Powders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/40c241c7-5d33-4634-a42e-86385fa0b194/download,University of Texas at Austin,"Thermal properties of additive manufacturing (AM) solids and precursor materials are important
factors for build process and part performance. However, measured thermal properties are not
well documented, despite being used extensively in AM modeling and simulation. The National
Institute of Standards and Technology (NIST) and the University of Louisville are developing the
measurement science for AM material thermal properties. New measurement methods, sample
preparation techniques, and results are demonstrated for laser flash (LF) thermal diffusivity
measurements on metal AM solids and powders. Due to the complexity of these materials, new
sample fabrication methods are developed and demonstrated. Results from LF measurements are
presented and compared.",,,,,,
"['Ji, Yi', 'Taylor, Samantha', 'Fish, Scott', 'Beaman, Joseph']",2021-11-03T21:20:24Z,2021-11-03T21:20:24Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89935,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['cooldown phase', 'cool down control', 'thermal simulation', 'validation', 'selective laser sintering']",Thermal Simulation and Experiment Validation of Cooldown Phase of Selective Laser Sintering (SLS),Conference paper,https://repositories.lib.utexas.edu//bitstreams/45c192fc-48b9-4cc0-9e70-cbb1694beeb7/download,University of Texas at Austin,"Thermal stresses, induced by inhomogeneous temperature distribution inside a part during
the cooldown phase of selective laser sintering, can be a major cause of part rejection for geometric
deviation from its as-built specification. A validated cooldown simulation can provide predictions
of temperature distribution in both parts and part cake which may enable alternative cooling
profiles to reduce the likelihood of such rejections. This work describes experiments and
comparative simulations developed to validate a sample tool for developing cool down control
profiles in an SLS machine. In the experiments, thermocouples were inserted inside the part cake
to monitor temperature at preselected locations during cooldown. The results from initial
experiments and simulations were compared at these locations, to obtain improved estimates of
uncertain powder conductivity and convective heat transfer parameters. The resulting simulation
was then compared with independent experiments to evaluate the accuracy of such simulations.
Though diffusion time in the part cake prevents active closed loop control in cooldown based on
thermal measurements at the part, the simulation can be used to determine an open loop control
profile for the build box heaters based on temperature gradient and resultant stresses inside the
part.",,,,,,
"['Huseynov, Orkhan', 'Al-Shaikh Ali, Mohammad', 'Fidan, Ismail']",2024-03-26T20:20:56Z,2024-03-26T20:20:56Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124393', 'https://doi.org/10.26153/tsw/51001']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'material extrusion', 'thermal simulation', 'print bed', 'thermal history']",THERMAL SIMULATION OF THE MATERIAL EXTRUSION PROCESS WITH DIFFERENT PRINT BED BOUNDARY CONDITIONS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/16ddba92-fca1-4859-9b67-fc58b07f096c/download,University of Texas at Austin,"The temperature evolution in the material extrusion (MEX) process significantly affects the
stability and bonding of 3D printed parts. Numerous studies have focused on developing models
to capture the temperature history of the MEX process. However, there remains a need to explore
the influence of different boundary conditions applied to the print bed. Additionally, the size of the
bed relative to the 3D printed object has not been extensively investigated. This study aims to
analyze the thermal behavior of the first layer in MEX by considering various boundary conditions
and bed sizes. The obtained results will contribute to the development of faster yet reliable models
for simulating the temperature variation in the MEX process.",,,,,,
"['Liu, Tao', 'Kinzel, Edward C.', 'Leu, Ming C.']",2024-03-27T16:00:08Z,2024-03-27T16:00:08Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124497', 'https://doi.org/10.26153/tsw/51105']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'thermal stress', 'additive manufacturing']",Thermal Stress Prediction in Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/455580a6-bdbd-41ef-be31-dcc2e444567b/download,,"This research applies Green's function solutions to simulate temperature and thermal stress fields
in laser powder-bed fusion (LPBF) processes. Using a semi-infinite domain and 2D Gaussian laser
profiles, the analytical model achieves high computational efficiency, has the potential for realtime controls and predictions in LPBF processes. The model highlights the role of principal
stresses in determining crack formations, aligning closely with experimental results.",,,,,,
"['Cheng, Bo', 'Chou, Kevin']",2021-10-18T21:25:59Z,2021-10-18T21:25:59Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89251,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['electron beam additive manufacturing', 'overhang', 'thermomechanical simulation']",Thermal Stresses Associated with Part Overhang Geometry in Electron Beam Additive Manufacturing: Process Parameter Effects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e0650f15-05bd-4d17-b94a-9e2e0cdd6ed0/download,University of Texas at Austin,"For powder-bed electron beam additive manufacturing (EBAM), support structures are
required when fabricating an overhang to prevent defects such as curling, which is due to the
complex thermomechanical process in EBAM. In this study, finite element modeling is
developed to simulate the thermomechanical process in EBAM in building overhang part.
Thermomechanical characteristics such as thermal gradients and thermal stresses around the
overhang build are evaluated and analyzed. The model is applied to evaluate process parameter
effects on the severity of thermal stresses. The major results are summarized as follows. For a
uniform set of process parameters, the overhang areas have a higher maximum temperature, a
higher tensile stress, and a larger distortion than the areas above a solid substrate. A higher
energy density input, e.g., a lower beam speed or a higher beam current may cause more severe
curling at the overhang area.",,,,,,
"['Pohl, Haiko', 'Simchi, Abdolreza', 'Issa, Munther', 'Dias, Hugo Calefi']",2019-10-18T15:32:51Z,2019-10-18T15:32:51Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76240', 'http://dx.doi.org/10.26153/tsw/3329']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Sintering,Thermal Stresses in Direct Metal Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/390411c4-073b-4391-bb76-a43cf7d760e9/download,,"In Direct Metal Laser Sintering objects are created by sequential sintering loose metal
powder particles by means of laser technology. When the laser sintering process involves
temperature gradients, thermal stresses develop. Corresponding residual stresses induce warping
of the densified structure leading to unacceptable tolerance losses. This paper examines the role
of laser beam scan patterns on the resulting stresses and warpage of direct metal laser sintered
plate-shaped specimens. The effects of a large variety of laser sintering parameters are described.
It can be shown that the optimization of process conditions and material aspects results in a
significant reduction of thermal stresses.",,,,,,
"['Mertens, A.', 'Dedry, O.', 'Reuter, D.', 'Rigo, O.', 'Lecomte-Beckers, J.']",2021-10-21T15:27:54Z,2021-10-21T15:27:54Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89396,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Laser Beam Melting', 'AlSi10Mg', 'thermal treatments']",Thermal Treatments of AlSi10Mg Processed by Laser Beam Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1576c5fb-259a-4b2d-9a1a-a9663f89f6b6/download,University of Texas at Austin,"Recent studies have shown that AlSi10Mg processed by Laser Beam Melting (LBM)
exhibits a much finer microstructure when compared to its cast counterpart as a consequence of
the much faster cooling rates imposed in the LBM process. Such microstructural refinement
causes a significant increase in strength and hardness, to such an extent that as-fabricated LBM
AlSi10Mg was reported to present hardness value of 127 ± 3 Hv0.5, similar to the hardness of
high pressure die cast AlSi10Mg in the aged condition (i.e. 130-133 Hv). Yet, little attention has
been given so far to the influence of thermal treatments on the microstructure and mechanical
behavior of LBM AlSi10Mg. The present work hence aims to investigate the effect of two
different types of heat treatments – i.e. (i) stress relief and (ii) solutionizing and ageing − on the
microstructure, hardness and tensile properties of LBM AlSi10Mg.",,,,,,
"['Duty, Chad', 'Johnson, Ryan', 'Jean, Daniel', 'Bondi, Scott', 'Lackey, W. Jack']",2019-10-18T15:36:30Z,2019-10-18T15:36:30Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76241', 'http://dx.doi.org/10.26153/tsw/3330']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Deposition,"Thermal, Fluid, and Mass Transport Modeling of a Gas-Jet Reagent Delivery System for Laser Chemical Vapor Deposition (LCVD)",Conference paper,https://repositories.lib.utexas.edu//bitstreams/76de83c2-67d6-4ba3-a7b9-0e70253973cc/download,,"A gas-jet reagent delivery system for laser chemical vapor deposition (LCVD) is modeled
with respect to heat transfer, fluid flow, and mass transport. A commercial package was used to
model the geometry and flow field surrounding an LCVD reaction zone. The deposition
temperature was analyzed for various materials and flow conditions. The forced flow
environment was compared against buoyancy-driven flow, which is more typical of a statically
filled chamber. A finite difference code was also developed to analyze the effect of the gas-jet
on the concentration gradients above the deposition zone.","This work was supported by the National Science Foundation, the Engineering Research
Program of the Office of Basic Energy Sciences at the U. S. Department of Energy and the
Georgia Institute of Technology with significant input from Dr. Andrei Fedorov.",,,,,
"['Ulett, J.S.', 'Benson-Tolle, T.', 'Schultz, J.W.', 'Chartoff, R. P.']",2019-02-26T17:57:42Z,2019-02-26T17:57:42Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73491', 'http://dx.doi.org/10.26153/tsw/641']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['Liquid crystal', 'stereolithography']",Thermal-Expansion and Fracture Toughness Properties ofParts made from Liquid Crystal Stereolithography Resins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f93474a6-5523-4049-be63-a5c9525935c4/download,,"Liquid crystal (LC) resins are a new kind ofstereolithography material that can produce
parts with structured or ordered morphologies instead ofthe amorphous morphologies that result
from standard resins. The LC molecules can be aligned before cure resulting in an anisotropic
crosslinked network when the laser induced polymerization ""locks-in"" the alignment. Previous
papers have explored liquid crystal orientation dynamics [1], the effects of orientation on viscoelastic and mechanical properties [2,3], and the processing ofLC resins by stereolithography [4].
This paper considers the effects ofmorphology on fracture toughness and thermal-expansion
properties. Both toughness and thermal-stability continue to be important issues for
stereolithography parts. The use ofLC resins may provide a way to significantly improve
performance in both ofthese areas, and in addition result in parts with high upper use .
temperatures.",,,,,,
"['Weflen, E.D.', 'Peters, F.E.', 'Frank, M.C.']",2023-04-03T17:30:09Z,2023-04-03T17:30:09Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117723', 'http://dx.doi.org/10.26153/tsw/44602']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Additive manufacturing,Thermally Switchable Build Table by Mechanical Interlocking for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e20718d-c2c2-4104-84cd-dfbd82c03652/download,,"This work presents a method for achieving a thermally switchable bond on a build table 
for Additive Manufacturing using mechanically interlocking features. Removal of parts from the 
build table remains a challenge. Furthermore, the residual stress that develops as multiple layers 
are deposited in an ambient environment can lead to the part detaching from the build table if 
bonding is insufficient. To achieve ample part to build table bonding, undercut features are 
machined into a metal build table onto which the molten polymer is extruded. Upon solidification, 
a mechanical bond is formed. The part can then be easily removed through rapid heating of the 
undercut features, resulting in a loss of mechanical bonding. We present results from our lab-scale 
setup allowing fundamental studies of the core physics. The method can easily be scaled larger or 
smaller by proportionally sizing the undercut features to the plastic extrusion bead size and 
parameters.",,,,,,
"['Bharvirkar, Manish', 'Nguyen, Phong', 'Pistor, Christoph']",2019-03-14T17:15:30Z,2019-03-14T17:15:30Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73682', 'http://dx.doi.org/10.26153/tsw/824']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'ABS']",Thermo-mechanical Analysis of Parts Fabricated via Fused Deposition Modeling (FDM),Conference paper,https://repositories.lib.utexas.edu//bitstreams/300b82e7-7862-479c-81fa-b629bd6797bf/download,,"The quality of Fused Deposition Modeling parts that are built using the standard parallel
road approach depends significantly on the orientation of the slices. In this study the expansion
coefficient, tensile strength and elastic. modulus of FDM parts made from ABS were determined
experimentally. The parts were built using the standard toolpath (parallel roads) with a uni
directional stacking sequence. The results were used to determine the thermo-mechanical
properties for an.individual slice. Classical lamination theory was applied to predict properties
and stiffness of matrix parts with arbitrarily oriented stacking sequences. The results of these
predictions are compared with experimental results for a quasi-isotropic stacking sequence.",,,,,,
"['Zekovic, Srdja', 'Dwivedi, Rajeev', 'Kovacevic, Radovan']",2020-02-21T21:40:41Z,2020-02-21T21:40:41Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80072', 'http://dx.doi.org/10.26153/tsw/7093']",eng,2005 International Solid Freeform Fabrication Symposium,Open,finite element analysis,Thermo-structural Finite Element Analysis of Direct Laser Metal Deposited Thin-Walled Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd487346-0b12-47cb-aabe-c69325356feb/download,,"Multilayer direct laser metal deposition is a fabrication process in which the parts are fabricated
by creating a molten pool into which particles are injected. During fabrication, a complex
thermal history is experienced in different regions of the build, depending on the process
parameters and part geometry. The thermal history induces residual stress accumulation in the
buildup, which is the main cause of cracking during the fabrication. The management of residual
stress and the resulting distortion is a critical factor for the success of the process. A thermostructural finite element model (FEM) of the process is developed, and the analysis reveals
different patterns of residual stress in the thin-walled structures depending on the deposition
strategy and the geometry of the structures. The residual stress patterns obtained from finite
element analysis (FEA) are in good agreement with the experimental results.",,,,,,
"['Gunaratnam, Rana', 'Sparks, Todd E.', 'Liou, Frank']",2020-03-09T13:27:20Z,2020-03-09T13:27:20Z,8/28/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80173', 'http://dx.doi.org/10.26153/tsw/7192']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Laser Aided Manufacturing Process,Thermocouple Embedding for the Production of a Substrate for Rapid Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ab469a19-7637-4d61-aae4-71897cb8eb4a/download,,,,,,,,
"['Karnati, Sreekar', 'Sparks, Todd', 'Liou, Frank']",2021-10-19T15:15:04Z,2021-10-19T15:15:04Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89294,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'thermal qualities', 'thin wall geometry', 'thermography']",Thermographic Investigation of Laser Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cbd088cc-4efe-4a07-b70e-a84e1b60398e/download,University of Texas at Austin,"Primitive stages of studies on and with additive manufacturing techniques popularly involve thin
wall geometry. In the current effort attempts were made to capture various thermal aspects
during deposition of a thin wall geometry. The thermo-graphic data was captured using a FLIR
A615 infrared camera. Post processing using edge detection algorithms and image processing
techniques, the geometric and thermal aspects of meltpool and tail of the meltpool were obtained.
The effect of geometry and power on shape of the meltpool and its tail were obtained. The
depositions of SS 316 with varying power. These observations were discussed and analyzed in
aim to perform planned deposition of functionally gradient materials in future.",,,,,,
"['Lane, Brandon', 'Moylan, Shawn', 'Whitenton, Eric', 'Ma, Li']",2021-10-20T20:55:37Z,2021-10-20T20:55:37Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89360,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'commercial manufacturing', 'thermographic measurements', 'melt pool region', 'National Institute Standards and Technology']",Thermographic Measurements of the Commercial Laser Powder Bed Fusion Process at NIST,Conference paper,https://repositories.lib.utexas.edu//bitstreams/593588e0-bd9a-4ec9-af3e-e4102312c6ce/download,University of Texas at Austin,"Measurement of the high-temperature melt pool region in the laser powder bed fusion (LPBF) process is a primary focus of researchers to further understand the dynamic physics of the
heating, melting, adhesion, and cooling which define this commercially popular additive
manufacturing process. This paper will detail the design, execution, and results of high speed,
high magnification in-situ thermographic measurements conducted at the National Institute of
Standards and Technology (NIST) focusing on the melt pool region of a commercial L-PBF
process. Multiple phenomena are observed including plasma plume and hot particle ejection
from the melt region. The thermographic measurement process will be detailed with emphasis
on the ‘measurability’ of observed phenomena and the sources of measurement uncertainty.
Further discussion will relate these thermographic results to other efforts at NIST towards L-PBF
process finite element simulation and development of in-situ sensing and control methodologies.",,,,,,
"['Krauss, H.', 'Eschey, C.', 'Zaeh, M.F.']",2021-10-07T14:53:16Z,2021-10-07T14:53:16Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88469', 'http://dx.doi.org/10.26153/tsw/15406']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Melting', 'thermography', 'process errors', 'heat dissipation', 'temperature distribution']",Thermography for Monitoring the Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4187b676-157b-43f6-a17b-50f9a8d480dc/download,University of Texas at Austin,"A lot of strategies exist to monitor and control additive layer manufacturing processes.
Basically one can distinguish between coaxially monitoring the process zone and monitoring the
complete layer currently being built. Since Selective Laser Melting is a thermal process, a lot of
information about the process and in consequence about the resulting part quality can be gathered
by monitoring the temperature distribution of a complete layer and its temporal evolution. It
depends on the geometrical configuration of parts being built and the quality of the powder layer
deposition. In this paper, process errors originating from insufficient heat dissipation are
investigated as well as the limits for detecting pores and other irregularities by observation of the
temperature distribution.",,,,,,
"['Chin, R.K.', 'Beuth, J.L.', 'Amon, C.H.']",2018-11-16T14:55:26Z,2018-11-16T14:55:26Z,1996,Mechanical Engineering,doi:10.15781/T2QB9VR6J,http://hdl.handle.net/2152/70283,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SDM', 'manufacturing methods', 'stress distributions']",Thermomechanical Modeling of Successive Material Deposition in Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/caf43ddb-31d5-4db4-a935-4c6f0a33026c/download,,"Residual stress build-up due to successive deposition of superheated molten metal onto
metal substrates is modeled for application to layered manufacturing methods. This work is
specifically applied to microcasting, which is a deposition process used within shape deposition
manufacturing. One-dimensional thennal and mechanical models are used to predict temperature
and stress evolution related to two physical phenomena. First, the effect of thennal cycling by
newly deposited material on stress states in previously deposited and cooled layers is investigated.
Here, deposited molten metal solidifies and cools to room temperature before new molten metal is
deposited. For this case, predicted stress distributions as a function of depth are relatively
uncomplicated and can be related to residual stress-induced part tolerance loss. In the second case,
the effect of localized preheating by previously deposited material is investigated. In this model,
molten metal is successively deposited at a rate comparable to that used to deposit individual
droplets in the microcasting process. Results indicate that although preheating by previously
deposited material strongly affects transient stresses, final stress states are not substantially altered.",,,,,,
"['Jaksch, A.', 'Spinola, M.', 'Cholewa, C.', 'Pflug, L.', 'Stingl, M.', 'Drummer, D.']",2023-04-05T17:14:02Z,2023-04-05T17:14:02Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117780', 'http://dx.doi.org/10.26153/tsw/44659']",eng,2022 International Solid Freeform Fabrication Symposium,Open,PBF-LB/P,Thin-Walled Part Properties in PBF-LB/P — Experimental Understanding and Nonlocal Material Model,Conference paper,https://repositories.lib.utexas.edu//bitstreams/77c6dd55-0296-472a-bf75-3a9a869f7876/download,,"to fully realizing the potential of lightweight design in powder bed fusion of polymers (PBF-LB/P). In 
this work, parts built with rectangular cross sections of different sizes and orientations are described by their 
geometry, surface roughness, mechanical characteristics, and specific component geometry dependent on energy 
input. Experimental findings are supported by a nonlocal material model developed to adequately describe 
weakened material behavior at the surface of PBF-LB/P parts. This approach allows the simulation of the elastic 
modulus and density for complex part geometries while simultaneously considering boundary effects. 
Furthermore, the volume-surface ratio for thin-walled components were linearly correlated to the rectangular 
cross sections in different building orientations. This uniformity indicates that this ratio is a suitable quantity to 
consider. Therefore, the process knowledge is improved, especially in new design standards for thin-walled 
structures in PBF-LB/P.",,,,,,
"['Boillat, E.', 'Kolossov, S.', 'Glardon, R.']",2019-10-24T17:46:54Z,2019-10-24T17:46:54Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77406', 'http://dx.doi.org/10.26153/tsw/4495']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Laser Sintering,A Three Dimensional FEM-Simulation of the Selective Laser Sintering Process with Locally Refined Meshes and Non-Constant Thermal Conductivity,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5d8a9fa0-7863-4dbf-b56a-4b0908e1a52d/download,,,,,,,,
"Sun, Ming-shen M.",2018-04-16T17:27:11Z,2018-04-16T17:27:11Z,1991,Mechanical Engineering,doi:10.15781/T28S4K60Q,http://hdl.handle.net/2152/64311,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'Selective Laser Sintering', 'model', 'sintering']",A Three Dimensional Model for Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b4030075-4cf9-47b9-95b9-30d462a6a5a1/download,,,,,,,,
"['Kernan, Brian D.', 'Sachs, Emanuel M.', 'Oliveria, Mark A.', 'Cima, Michael J.']",2019-11-21T18:44:30Z,2019-11-21T18:44:30Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78566', 'http://dx.doi.org/10.26153/tsw/5622']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Carbide-Cobalt,Three Dimensional Printing of Tungsten Carbide-Cobalt Using a Cobalt Oxide Precursor,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5c3b7a15-5ce9-4894-85d5-54e68f187fcd/download,,"Tungsten Carbide 10 wt% Cobalt parts were formed by Slurry-based Three
Dimensional Printing (3DPTM). The slurry contained a mixture of Tungsten Carbide and
Cobalt Oxide powders, as well as dispersing and redispersing agents. The cobalt oxide is
fully reduced to cobalt metal during the early stages of the sintering process. A new binder
system, polyethylenimine, is described for use with powders with acidic surfaces, such as
WC. Sintered densities approach the theoretical values for WC-10% Co, and the
microstructures produced are similar to those of conventionally processed (press and sinter)
materials. Up to four parts were produced in a single print run using a layer thickness of 25
Pm, with good dimensional agreement between them, and within the range of target
dimensions after sintering.",,,,,,
"['Cima, Michael J.', 'Sachs, Emanuel M.']",2018-04-17T17:59:40Z,2018-04-17T17:59:40Z,1991,Mechanical Engineering,doi:10.15781/T2DB7W70S,http://hdl.handle.net/2152/64335,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Department of Materials Science and Mechanical Engineering', 'Three Dimensional Printing', 'CAD', 'SLS']","Three Dimensional Printing: Form, Materials, and Performance",Conference paper,https://repositories.lib.utexas.edu//bitstreams/4a91dec9-3ba5-4a65-ba19-0e55500d2bb6/download,,,,,,,,
"['Sachs, Emanuel', 'Cima, Michael', 'Cornie, James']",2018-04-10T16:47:13Z,2018-04-10T16:47:13Z,1990,Mechanical Engineering,doi:10.15781/T2GT5FZ4F,http://hdl.handle.net/2152/64236,eng,1990 International Solid Freeform Fabrication Symposium,Open,"['Three Dimensional Printing', 'Industrial productivity', 'sequential formation', 'ink-jet printing']",Three Dimensional Printing: Rapid Tooling and Prototypes Directly from CAD Representation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c0ba7c81-35a2-497d-a309-e93acea1a79f/download,,"Industrial productivity and competitive success depend on fast, efficient product
development technologies. The flexible manufacture of tooling and mechanical prototypes
can greatly reduce the time required for bringing a product to market. Tooling frequently
dominates manufacturing time and cost, thereby determining the minimum economic batch
size for a given process. Tooling can be extremely complex and is generally one-of-a-kind,
requiring much human attention to detail. As a result, fabrication of tooling for such
processes as injection molding or lost wax casting, commonly requires several months of
work. Three Dimensional Printing offers an alternative to conventional options which do
not adequately answer the demands for rapid prototyping and speedy, low-cost production
of tooling.",,,,,,
"['Awenlimobor, Aigbe', 'Smith, Douglas E.', 'Wang, Zhaogui', 'Luo, Chenjun']",2023-01-26T15:28:45Z,2023-01-26T15:28:45Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117317', 'http://dx.doi.org/10.26153/tsw/44198']",eng,2022 International Solid Freeform Fabrication Symposium,Open,3D,Three-dimensional (3D) Simulation of Micro-Void Development within Large Scale Polymer Composite Deposition Beads,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e7c85a4-8280-4640-88d8-9c482d6d6ee6/download,,"Manufacturing (BAAM) are largely affected by inherent bead microstructural features 
such as voids. Unfortunately, our understanding of void nucleation and evolution during polymer 
deposition process is lacking. Flow modeling focused on the associated microstructural formation 
provides a means for better understanding the process-structure-properties relations in large area 
extrusion deposition additive manufacturing of fiber reinforced composites. Our prior computational 
effort that investigated mechanisms that may promote micro-void formation was based on 2-dimensional 
planar models of a single ellipsoidal fiber motion in purely viscous polymer extrusion/deposition flow 
through a BAAM nozzle. Here we present a 3D finite element modelling approach to simulate single fiber 
out-of-plane rotations utilizing velocity and velocity gradient values computed along streamlines 
obtained from a 3D extrusion/deposition simulation of the BAAM polymer deposition process. The 
pressure distribution on the fiber’s surface along the flow path provides new insight into potential 
micro-void nucleation mechanism. Results show low pressure regions occur near the fiber’s surface 
which varies across the printed bead and through its thickness.",,,,,,
"['Chen, Y.', 'Bartzos, D.', 'Liang, S.', 'Lu, Y.', 'Jafari, M.', 'Langrana, N.A.', 'Pilleux, M.E.', 'Allahverdi, M.', 'Danforth, S.C.', 'Safari, A.']",2019-09-18T16:34:12Z,2019-09-18T16:34:12Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75899', 'http://dx.doi.org/10.26153/tsw/2999']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Alumina,Three-dimensional Alumina Photonic Bandgap Structures: Numerical Simulation and Fabrication by Fused Deposition of Multimaterials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0c445a1f-4d91-43b7-a140-53901622e6a2/download,,"Three-dimensional photonic bandgap (PBG) structures using alumina (Al2O3) as the
high permittivity material were modeled and fabricated. A finite element method and a realtime electromagnetic wave propagation software were used to simulate and design the layered
PBG structures for their use in the microwave frequency range. The modeling obtained a 3-D
photonic bandgap in the 16-23 GHz range. Fused deposition of multimaterials (FDMM)
technology was then used to manufacture PBG structures. FDMM provides a computercontrolled process to generate 3-D structures, allowing high fabrication flexibility and
efficiency. These PBG structures are potential candidates for applications in advanced
communication systems.",New Jersey Commission of Science and Technology under the Research Excellence Program.,,,,,"['https://sffsymposium.engr.utexas.edu/Manuscripts/2000/2000-04-Bandyopadhyay.pdf', 'https://sffsymposium.engr.utexas.edu/Manuscripts/2000/2000-05-Chen.pdf']"
"['Mizukami, Yoshiaki', 'Osakada, Kozo']",2019-10-24T18:27:08Z,2019-10-24T18:27:08Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77420', 'http://dx.doi.org/10.26153/tsw/4509']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Metallic Parts,Three-Dimensional Fabrication of Metallic Parts and Molds Using Hybrid Process of Powder Layer Compaction and Milling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/14876e36-2635-4863-b1ef-b34c6f234667/download,,"In order to produce three-dimensional models with cemented carbide powders, a freeform
fabrication method named Layered Compaction Manufacturing (LCM), which is a hybrid process
of powder compaction and CNC milling in layer-by-layer additive manner, is proposed. The
feasibility of the LCM process is confirmed by making a WC-9wt%Co carbide model. The
connecting strength between the layers of the model after sintering is evaluated by the bending
test. It is found that the transverse strength of the sintered products is higher than 2 GPa.
 A WC-9wt%Co model with inside channels for temperature control is successfully fabricated
using a paraffin wax as a sacrificial material in the LCM process.",,,,,,
"['Han, Quanquan', 'Setchi, Rossitza', 'Evans, Sam L.', 'Qiu, Chunlei']",2021-10-26T18:10:31Z,2021-10-26T18:10:31Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89546,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'thermal performance', 'three-dimensional finite element', 'Al-Al2O3 powder', 'aluminum-based composites']",Three-Dimensional Finite Element Thermal Analysis in Selective Laser Melting of Al-Al2O3 Powder,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47eef9e5-e092-4423-be21-c7fe1c0dbd62/download,University of Texas at Austin,"The selective laser melting (SLM) of aluminium-based composites continues to be a
challenge due to the high reflectivity, high thermal conductivity and oxidation of aluminium, all
of which directly influence the thermal performance of each layer during SLM. Due to the
extremely rapid melting and cooling rate of aluminium, however, it is difficult to measure thermal
performance within practical SLM applications. A three-dimensional finite element simulation
model is thus developed in this study to simulate the transient temperature distribution and molten
pool dimensions of the premier layer during the SLM of Al-Al2O3 composite powder. In order to
produce high-quality parts with minimum defects in a highly efficient manner, the predicted
optimum volumetric energy density is found to be 40 J/mm3
, with laser power 300 W, scanning
speed 1000 mm/s, hatch spacing 150 μm and layer thickness 50 μm; the molten pool size that is
produced is 165 μm in length, 160 μm in width and 77 μm in depth, with a predicted maximum
temperature of around 3400°C. All of these factors may contribute to the creation of good
metallurgic bonding.",,,,,,
"['Josupeit, Stefan', 'Schmid, Hans-Joachim']",2021-10-12T20:05:54Z,2021-10-12T20:05:54Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88729', 'http://dx.doi.org/10.26153/tsw/15663']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['polymer laser sintering', 'laser sintering', 'temperature measurement', 'part cakes', 'job parameters']",Three-Dimensional In-Process Temperature Measurement of Laser Sintered Part Cakes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/03dd299f-6ebd-4055-a79f-bb8b98b52a25/download,University of Texas at Austin,"An uneven temperature distribution and varying cooling rates at different positions within
the part cake are two of the most important challenges regarding the part quality and reproducibility
of the polymer laser sintering process. In the presented work, a temperature measurement system
is implemented within an EOSINT P395 laser sintering system. It allows the determination of a
three dimensional temperature distribution and history during the full build and cooling process.
The influence of important job parameters, for example the packing density, job height and layer
thickness, can be figured out. In combination with a finite element simulation of the cooling
process, the temperature measurement will be the basis for optimized process controls.",,,,,,
"['Zhou, Xiangman', 'Zhang, Haiou', 'Wang, Guilan']",2021-10-26T18:52:30Z,2021-10-26T18:52:30Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89555,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['stacking deposition', 'arc welding based additive manufacturing', 'AWAM', 'arc model', 'metal transport']",Three-Dimensional Numerical Simulation of Arc and Metal Transport for Stacking Deposition in Arc Welding Based Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/184821d5-b907-4e47-a512-6cf25383b202/download,University of Texas at Austin,"The stacking deposition in arc welding based additive manufacturing (AWAM) results in complex
surfaces of deposited layer. Therefore the electromagnetic force in molten pool, arc pressure, plasma shear
stress and heat flux on molten pool surface are not the same as the conventional welding. A three-dimensional weak coupling modeling method has been developed to simulate the arc, molten pool dynamic
and droplet impingement of stacking deposition. In the arc model, the molten pool is simplified to be solid
state on the basis of experimentally observed result. The arc is simulated firstly, and then the electromagnetic
force, arc pressure, plasma shear stress and heat flux are extracted and transmitted to metal transport model.
The molten pool morphology of simulated result accords well with experimental result, which indicates that
this weak coupling modeling method is capable of simulating the complex heat and mass transfer behaviors
in AWAM.",,,,,,
"['DeNava, Erick', 'Navarrete, Misael', 'Lopes, Amit', 'Alawneh, Mohammed', 'Contreras, Marlene', 'Muse, Dan', 'Castillo, Silvia', 'MacDonald, Eric']",2021-09-23T21:25:21Z,2021-09-23T21:25:21Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88026', 'http://dx.doi.org/10.26153/tsw/14967']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'stererolithography', 'direct-write', 'hybrid integration manufacturing', '3D off-axis component placement', '3D off-axis routing']",Three-Dimensional Off-Axis Component Placement and Routing for Electronics Integration using Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53e0d410-6edb-4355-9919-c7778e2d4dfc/download,,"Traditional placement of transistors in chips and components on printed circuit boards has 
been constrained in two dimensions. Routing of electrical signals in these devices has been 
extended to two and half dimensions by virtue of additional routing layers which are connected 
through vertical vias (i.e. four layer printed circuit boards or CMOS chips with seven layers of 
metal routing); however, truly three-dimensional off-axis component placement and routing have 
not yet been explored. Solid freeform fabrication provides the means of creating a dielectric 
substrate suitable for these electronics with sockets for components and channels for 
interconnect. Direct write dispensing of conductive inks or epoxies into these channels has been 
reported previously for electronics applications, but was generally confined to two dimensions in 
a fashion similar to traditional electronics. The current research describes a demonstration 
prototype in which components are placed off-axis to fulfill application requirements (for a 
three-dimensional magnetic flux sensor system) and where sections are routed off-axis as well – 
all of which provides new levels of design freedom for the implementation of electronics 
systems.",,,,,,
"[""D'Costa, D.J."", 'Dimovski, S.D.', 'Lin., F.', 'El-Raghy, T.', 'Barsoum, M.W.', 'Sun, W.']",2019-09-20T18:16:26Z,2019-09-20T18:16:26Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75923', 'http://dx.doi.org/10.26153/tsw/3022']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Ductile,Three-Dimensional Printing of Layered Machinable Ductile Carbide 80,Conference paper,https://repositories.lib.utexas.edu//bitstreams/417b5459-5862-442f-9c3f-32ab6648b621/download,,"Ti3SiC2 carbide represents a new class of ceramics with excellent electrical and mechanical properties. This paper presents our preliminary studying on using 3D printing technique, combining with cold isostatic pressing and sintering processing to prototype Ti3SiC2 carbide components. The basic mechanical, electrical and thermal properties of Ti3SiC2 carbide material will be reviewed. Results in die and mold-free 3D printing processing of Ti3SiC2 carbide prototyping will be reported. The SEM
characterization of the prototypes and the correlation with the processing parameters will be presented",,,,,,
"['Pal, Deepanker', 'Stucker, Brent E.']",2021-10-05T19:45:22Z,2021-10-05T19:45:22Z,8/22/12,Mechanical Engineering,,"['https://hdl.handle.net/2152/88419', 'http://dx.doi.org/10.26153/tsw/15358']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic consolidation', 'Al 3003-H18 alloy', 'homogenization', 'pure aluminum']",Time Homogenization of Al3003 H-18 Foils Undergoing Metallurgical Bonding Using Ultrasonic Consolidation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93e0052c-3456-4b09-90bb-2184e9982078/download,University of Texas at Austin,"A dislocation density based finite element model was formulated and initially validated
using published experimental data for simple shear deformation of a single crystal pure
aluminum and uniaxial tension of bulk polycrystalline Al 3003-H18 alloy. The model was
extended to predict the deformation behavior of 150µm Al 3003-H18 foils undergoing ultrasonic
consolidation (UC). The simulated results were in good agreement with the experimental results
for the evolution of linear weld density and embrittlement due to grain substructure formation. A
novel time homogenization approach has been further formulated which significantly reduces the
computational overhead. The time-homogenization approach uses the Almost Periodic Time
Homogenization (APTH) operator based on an asymptotic Forward-Euler scheme for integrating
the coarse time increments. The computational efficiency is proportional to the ratio of coarse to
fine time scales.",,,,,,
"['Male, J.', 'Tsang, H.', 'Bennett, G.']",2018-11-08T18:52:30Z,2018-11-08T18:52:30Z,1996,Mechanical Engineering,doi:10.15781/T2PC2TV4W,http://hdl.handle.net/2152/69900,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['3D Systems Stereolithography', 'SLS', 'prototypes']","A Time, Cost and Accuracy Comparison of Soft Tooling for Investment Casting Produced Using Stereolithography Techniques",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7afa9d8-028b-4569-a585-538dcb67af79/download,,"Investment casting is increasingly widely used in the production ofmetal prototypes in
conjunction with rapid prototyping (RP) technologies. Some types ofRP models can be used
directly as sacrificial patterns in the casting process, but this can prove costly and time
consuming where a number of castings are required.
Soft tooling such as resin tooling and silicon rubber tooling are used to produce a
number of wax patterns for subsequent casting, using an RP model as the master.
Stereolithography faced tools are starting to be used as in some circumstances they can offer
time savings over other soft tooling methods. This paper aims to compare the costs and times
taken to produce wax patterns for use in investment casting using the different soft tooling
techniques and QuickCastTM build style for use as a casting pattern.",,,,,,
"['Stone, Ronnie F.P.', 'Wang, Junmin', 'Sha, Zhenghui']",2024-03-26T22:54:51Z,2024-03-26T22:54:51Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124435', 'https://doi.org/10.26153/tsw/51043']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['autonomous robotics systems', 'mobile robots', 'trajectory and path planning', 'intelligent manufacturing systems', 'swarm manufacturing']",Time-Optimal Path Planning for Heterogeneous Robots in Swarm Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2f6d8b7c-b246-445f-9c97-d5002488ecf6/download,University of Texas at Austin,"Time-optimal path planning is a critical problem in any system employing mobile robots. Much
of the literature on this problem operates under two major assumptions: the environment is static,
and the robots’ effective shapes are constant and discretized either as a circle or a sphere, disregarding the impact of the robot’s orientation on the overall task. These assumptions are restrictive in
swarm manufacturing, where the environment is dynamically changing and manufacturing robots
have geometric constraints for operation. For example, robots can not only move but also change
their effective shapes depending on the parts they carry or the material deposited. These variations can significantly impact the path-planning solution. In this paper, we propose a methodology
to find time-optimal paths in swarm manufacturing while explicitly considering the effective and
changing shapes of mobile robots and the dynamic obstacles surrounding them.",,,,,,
"['Xiong, Yi', 'Van Campen, Anke', 'Van Vlierberghe, Anje', 'Kempen, Karolien', 'Kruth, Jean-Pierre']",2021-11-02T20:21:12Z,2021-11-02T20:21:12Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89886,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['scan path', 'sliced geometry', 'time-optimal', 'geometry analysis', 'powder bed additive manufacturing']",Time-Optimal Scan Path Planning Based on Analysis of Sliced Geometry,Conference paper,https://repositories.lib.utexas.edu//bitstreams/115d8c44-8b10-4e2b-a341-bbaed0c44921/download,University of Texas at Austin,"In powder-bed based layered manufacturing, a focused and high power laser beam is guided
to travel through pre-defined trajectories with various process parameters such as the scan
speed, laser power, and beam diameter to consolidate powdered materials together. The predefined path, therefore, plays a significant role not only on the build part quality but also on
the build time. Current path planning strategies are defined only on the layer level. Although,
contours on one layer can be significantly different in the geometry shape. This paper proposes
an adaptive scan path planning method based on the geometric characteristic of contours. With
this approach, the user is able to control and optimize the scan path for contours with different
geometric types. An algorithm for determining the scanning direction to minimize the build
time is discussed in detail. A path planning approach for non-productive paths illustrates the
potential time gain applying more intelligent strategies.",,,,,,
"['Xu, Changxue', 'Zhang, Zhengyi', 'Fu, Jianzhong', 'Huang, Yong', 'Markwald, Roger R.']",2021-10-07T17:54:20Z,2021-10-07T17:54:20Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88495', 'http://dx.doi.org/10.26153/tsw/15429']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['inkjetting formation', 'alginate solution', 'droplet formation', 'organ printing']",Time-Resolved Study of Droplet Formation Process During Inkjetting of Alginate Solution,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cb374f78-5550-439e-82fe-d3d9dfd0b795/download,University of Texas at Austin,"Organ printing offers a great potential for the fabrication of three-dimensional (3D) living
organs by precisely layer-by-layer placing various tissue spheroids. Such fabricated organs may
replace some damaged or injured human organs, emerging as a promising solution to the
problem of organ donor shortage. As one of the key enabling technologies for organ printing,
inkjetting has been received much attention recently. It is of great importance to understand the
jetting and droplet formation processes during the inkjetting of typical biomaterials such as
alginate solution. The jetting behavior and breakup time during alginate inkjetting have been
studied using a time-resolved approach, and different pinch-off behaviors are classified. The
resulting knowledge will help better promote the inkjetting-based organ printing technology.",,,,,,
"['Harlan, Nicole', 'Bourell, David', 'Beaman, Joe']",2019-02-26T20:57:07Z,2019-02-26T20:57:07Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73501', 'http://dx.doi.org/10.26153/tsw/651']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['SLS', 'casting environments']",Titanium Casting Molds via Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fecde00c-2448-43d9-ac15-869ddbb9770c/download,,"A mold material system has been developed that can be SLS processed and used to
cast titanium alloys. Stabilized zirconia, chosen forits low reactivity with molten titanium,
has been sintered into mold shapes. The molds have been infiltrated with a colloidal
solution ofunstabilized zirconia and fired to create a partially stabilized structure. ·SEM
analysis shows that the unstabilized zirconia forms bridges between the larger stabilized
zirconia particles that provide strength to the mold.",,,,,,
"['Broek, Han J.', 'Horváth, Imre', 'Smit, Bram de']",2019-09-23T16:59:01Z,2019-09-23T16:59:01Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75971', 'http://dx.doi.org/10.26153/tsw/3070']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Flexible,Tool Path Generation for Flexible Blade Cutting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9ec1dd1d-0224-4b10-b076-5d737ff81f0f/download,,"Free Form Thick Layered Object Manufacturing FF-TLOM is based on application of a reshapeable cutting device, which allows a free form shaping of thick polystyrene foam layers. Once manufactured, these layers are stacked to produce a physical model. Tool path generation for the heated flexible blade tool is a challenging task, since it influences the quality of the manufactured objects as well as the effectiveness of the fabrication process. Them difficulties arise from the following facts: (a) when slicing is computed, the instantaneous tool positions are defined by matching the blade profile against the nominal shape of the CAD
model, (b) the tool positions calculated relative to the cut layers have to be converted into the global reference frame of the layer cutting equipment, (c) the resultant tool path should maintain the achieved preciseness approximating the front surface of the layers, and (d) it is impossible to calculate all points of the tool path in real time. This paper proposes an effective tool path calculation method for flexible blade cutting. The contour of the layers is converted into an ordered set of smooth and awkward boundary features. For the smooth boundary features, the tool positions are computed by dense sampling in order to achieve the optimal cutting.",,,,,,
"['Leite, M.', 'Cunha, J.', 'Sardinha, M.', 'Soares, B.', 'Reis, L.', 'Ribeiro, A.R.']",2021-11-15T22:22:22Z,2021-11-15T22:22:22Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90293', 'http://dx.doi.org/10.26153/tsw/17214']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['tool path generation', 'tool path', 'hybrid manufacturing', 'additive manufacturing', 'subtractive manufacturing']",Tool Path Generation for Hybrid Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/84e76553-92da-4337-9b91-a0411a5e72c8/download,University of Texas at Austin,"This paper presents a new approach to tool path generation for a hybrid additive-subtractive manufacturing
apparatus. The goal is the development of an integrated hybrid process, based on additive and subtractive
manufacturing, to produce complex geometries with continuous fiber reinforced thermoplastics.
The authors propose a novel system that can handle two heads: a filament deposition head and a milling
head. The system allows for additive, subtractive, additive followed by subtractive and additive and subtractive
at each layer.
Due to the use of continuous fiber reinforced thermoplastics the tool path trajectories will be different
depending on part geometry to accrue mechanical properties. To evaluate the proposed strategies, one example
with different features is provided on how to take an .stl file with a final geometry and generate the necessary
adjustments to enable the subtractive process.",,,,,,
"['Lim, Wei Sheng', 'Soh, Gim Song']",2024-03-26T23:28:28Z,2024-03-26T23:28:28Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124452', 'https://doi.org/10.26153/tsw/51060']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'toolpath']",Toolpath planning approach for parts with multiple revolving features for wire arc additive manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5348a16e-f73a-48bd-988e-d46308737065/download,University of Texas at Austin,"In wire arc additive manufacturing, existing toolpath planner for complex 3D shapes such
as propellers and turbines, with multiple revolving features radiating tend to utilize a cylindrical
slicing approach. Such slicing approaches are highly customized, complex, and not readily
available for printing such 3D shapes. In addition, such complicated motion planning requires
coordination between the print head and substrate motion to be synchronized well which can be
difficult to achieve. In this paper, we propose an alternative strategy using planar slicing and
adaptive width contour-based toolpath planner. To achieve this, a two-step approach is proposed
with the substrate and radiating elements treated as separate features. The substrate is printed with
part of the revolving feature, providing a flat surface for the second step to print from. The
approach is applied for a propeller over 0.7m in diameter where a 3D scan is done to compare with
the part model.",,,,,,
"['Crockett, Breanne', 'Borish, Michael']",2023-01-26T14:48:49Z,2023-01-26T14:48:49Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117310', 'http://dx.doi.org/10.26153/tsw/44191']",eng,2022 International Solid Freeform Fabrication Symposium,Open,k-means,Toolpath Planning for Multiple Build Points Using K-Means Clustering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c6983c0-115c-4880-bf57-f44a6fb4f88f/download,,"Traditional 3D printers deposit material at one build point at a time, often resulting in 
long print times. To reduce print time, 3D printers could increase throughput with parallel 
construction at multiple build points. The primary challenge in path planning for parallel 
construction is dividing an object between the build points. The object should be divided such 
that the workload is balanced, and the individual build areas are discrete. This work proposes a 
variation of k-means clustering for object division. The algorithm considers coordinate position 
and geometric area as an indicator of workload. This method is demonstrated on several test 
models to compare workload across the number of build points.",,,,,,
"['Stern, Michael', 'Bari, Joseph']",2021-11-04T20:03:34Z,2021-11-04T20:03:34Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90017', 'http://dx.doi.org/10.26153/16938']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['topological optimization', 'methdology', 'lightweight metallic mirrors', 'metallic mirrors', 'selective laser melting', 'additive manufacturing']",Topological Optimization and Methodology for Fabricating Additively Manufactured Lightweight Metallic Mirrors,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e7c1030-a84c-4c8e-9bbe-6a739464db71/download,University of Texas at Austin,"Imaging systems for space and airborne platforms have aggressive Size, Weight and
Power (SWaP) requirements. High quality, lightweight optics help enable these types of
systems. Today typical light weighting techniques are accomplished through removal of
material in the back structure with classical machining and the use of low-density, high-stiffness
materials such as beryllium. We present a novel methodology for generating lightweight
metallic mirrors that are fabricated by growing an additive manufactured blank, fly cutting the
surfaces to be mirrored, and post processing the faces by coating them with electroless nickel and
then diamond turning. This process was used in a case study for the development of a topology
optimized, low-weight and high-stiffness spinning mirror. The mirror was fabricated with
selective laser melting and post processed to deliver optical quality mirror surfaces.",,,,,,
"['Maheshwaraa, Uma', 'Seepersad, Carolyn Conner', 'Bourell, David']",2020-03-10T16:27:53Z,2020-03-10T16:27:53Z,2007,Mechanical Engineering,,"['https://hdl.handle.net/2152/80225', 'http://dx.doi.org/10.26153/tsw/7244']",eng,2007 International Solid Freeform Fabrication Symposium,Open,selective laser sintering,Topology Design and Freeform Fabrication of Deployable Structures with Lattice Skins,Conference paper,https://repositories.lib.utexas.edu//bitstreams/421e6fcb-2b65-43bd-b169-b75d75f4d82f/download,,"Solid freeform fabrication is particularly suitable for fabricating customized parts, but it has not
been used for fabricating deployable structures that can be stored in a compact configuration and
deployed quickly and easily in the field. In previous work, lattice structures have been
established as a feasible means of deploying parts. Before fabricating the parts with a selective
laser sintering (SLS) machine and Duraform® Flex material, lattice sub-skins are added
strategically beneath the surface of the part. The lattice structure provides elastic energy for
folding and deploying the structure or constrains expansion upon application of internal air
pressure. In this paper, a procedure is presented for optimizing the lattice skin topology for
improved overall performance of the structure, measured in terms of deviation from desired
surface profile. A ground structure-based topology optimization procedure is utilized, with a
penalization scheme that encourages convergence to sets of thick lattice elements that are
manufacturable and extremely thin lattice elements that are removed from the final structure. A
deployable wing is designed for a miniature unmanned aerial vehicle. A physical prototype of
the optimal configuration is fabricated with SLS and compared with the virtual prototype.",,,,,,
"['Jamalabad, Vikram R.', 'Chard, Jeffrey A.', 'Gasdaska, Charles J.', 'Clancy, Richard B.']",2019-02-22T17:50:11Z,2019-02-22T17:50:11Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73465', 'http://dx.doi.org/10.26153/tsw/615']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['FDC', 'theffiloplastic']",Topology Driven Improvement of FDC Build Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b3065a9a-166a-495d-8774-ce7bb531040c/download,,"The likeliest failure origin for advanced ceramics parts, prepared by fused
deposition, is a void from improper fill. Adequate filling of each cross-section is dependent upon the deposition toolpath. Cross-sectional spaces are conventionally
filled with pre-defined parameters. We propose that adaptive build parameters will
control variations in geometry and property of a part. Voids, overfilling,
incomplete bonding and excess traversing can be suppressed by adjusting the fill
parameters for cross-sectional areas. Improved build parameters and toolpath
allows for faster build time and components ofj full density. Some implementations
are discussed and presented.",,,,,,
"['Rashid, R.', 'Masood, S.H.', 'Ruan, D.', 'Palanisamy, S.', 'Huang, X.', 'Rahman Rashid, R.A.']",2021-11-09T19:49:42Z,2021-11-09T19:49:42Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90145', 'http://dx.doi.org/10.26153/tsw/17066']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['BESO method', 'selective laser melting', 'SLM', 'scanning strategy', 'flexural testing', 'energy absorption']",Topology Optimisation of Additively Manufactured Lattice Beams for Three-Point Bending Test,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b8c1c3b-7f59-48ac-a1e2-89da45f4610b/download,University of Texas at Austin,"The ability of additive manufacturing to develop parts with complex shapes has
increased the bandwidth of product design. This has facilitated the use of Topology
Optimisation (TO) techniques to optimise the distribution of material throughout the part,
thereby obtaining minimum weight without compromising the mechanical performance of the
component. In this study the Bi-directional Evolutionary Structural Optimisation (BESO)
algorithm was used to generate topologically optimised lattice unit cells. A simple bending
beam with 50% reduced volume was printed in two different unit cell arrangements using
Selective Laser Melting (SLM) process. Prior to printing, the density of SLM-printed AlSi12
samples was enhanced by using appropriate scanning strategy. The flexural properties of these
topology optimised beams were compared with the solid beam. The topologically optimised
beams absorbed about seven times more energy per unit volume till the displacement of
maximum bending load when compared with the solid beam at the same displacement.",,,,,,
"['Fey, Nicholas P.', 'South, Brian J.', 'Seepersad, Carolyn C.', 'Neptune, Richard R.']",2021-09-29T17:28:11Z,2021-09-29T17:28:11Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88195', 'http://dx.doi.org/10.26153/tsw/15136']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['prosthetic feet', 'topology optimization', 'selective laser sintering']",Topology Optimization and Freeform Fabrication Framework for Developing Prosthetic Feet,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa502765-c495-4630-b973-96d2df978687/download,University of Texas at Austin,"The ability to easily design and manufacture prosthetic feet with novel design characteristics
has great potential to improve amputee rehabilitation and care. This study presents a framework
using topology optimization methods to develop new prosthetic feet to be manufactured using
selective laser sintering. As an example application, the framework was used to generate a
prosthetic foot that minimizes material usage while trying to replicate the stiffness characteristics
of a commercially available carbon fiber foot. The solution was validated using finite element
methods to verify the foot’s loading response, and a prototype was manufactured. The result was
a novel foot design that with future design modification has the potential to improve amputee
gait by providing energy storage and return and reducing prosthetic weight.",,,,,,
"['Jiang, D.', 'Smith, D.E.']",2021-11-04T19:59:20Z,2021-11-04T19:59:20Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90016', 'http://dx.doi.org/10.26153/16937']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D material distribution', 'non-isotropic material distribution', 'material direction', 'material orientation', 'topology optimization', 'additive manufacturing']",Topology Optimization for 3D Material Distribution and Orientation in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67c69f3f-d102-4eb1-b542-68d491abafb3/download,University of Texas at Austin,"Products produced with Additive Manufacturing (AM) methods often have anisotropic
microstructure that forms as material layers are added during processing. Unfortunately, current
AM design methods do not accommodate the inherent non-isotropic behavior of these materials
when determining the best structural layout. This paper presents a three dimensional (3D)
topology optimization method that computes the best non-isotropic material distribution and
principal material direction for minimum compliance of a statically loaded non-isotropic AM
structure. The compliance objective function is calculated using the finite element method with
eight node 3D isoparametric elements, and design sensitivities with respect to both density and
material orientation are calculated with the Adjoint Variable method. We employ a linear
weighted sensitivity filter on the density variables to mitigate checker-boarding of the material
distribution. The optimization problem is solved with a nonlinear constraint-based Matlab (The
Mathworks, Inc., Natick, MA) optimization solver. Topology optimization of a 3D cantilever
beam with different print directions is given to demonstrate the applicability of the optimization
scheme.",,,,,,
"['Brackett, D.', 'Ashcroft, I.', 'Hague, R.']",2021-10-04T21:52:25Z,2021-10-04T21:52:25Z,8/17/11,Mechanical Engineering,,"['https://hdl.handle.net/2152/88361', 'http://dx.doi.org/10.26153/tsw/15300']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'additive manufacturing', 'solid isotropic material with penalization']",Topology Optimization for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dd9c4b52-36b4-4a1d-9985-adf0f660ed25/download,University of Texas at Austin,"This paper gives an overview of the issues and opportunities for the application of
topology optimization methods for additive manufacturing (AM). The main analysis issues
discussed are: how to achieve the maximum geometric resolution to allow the fine features easily
manufacturable by AM to be represented in the optimization model; the manufacturing
constraints to be considered, and the workflow modifications required to handle the geometric
complexity in the post optimization stages. The main manufacturing issues discussed are the
potential for realizing intermediate density regions, in the case of the solid isotropic material
with penalization (SIMP) approach, the use of small scale lattice structures, the use of multiple
material AM processes, and an approach to including support structure requirement as a
manufacturing constraint.",,,,,,
"['Ramsey, J.S.', 'Smith, D.E.']",2021-11-30T19:38:48Z,2021-11-30T19:38:48Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90524', 'http://dx.doi.org/10.26153/tsw/17443']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['topology optimization', 'material anisotropy', 'thermomechanical loading', 'anisotropic', 'additive manufacturing']",Topology Optimization for Anisotropic Thermomechanical Design in Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bc2cd8e7-fa60-4a4a-81d2-76e22057badc/download,University of Texas at Austin,"Topology optimization has emerged as an effective design approach that obtains complex
geometries suitable for additive manufacturing. However, additively manufactured structures
typically have anisotropic material properties, and residual thermal stresses result from
nonisothermal processes. This paper presents a new topology optimization-based approach that
incorporates both material anisotropy and weakly coupled thermomechanical loading into the
material layout computations. An optimality criterion-based update scheme minimizes
compliance or strain energy of a design space over material density and orientation where special
attention is given to the optimal material orientation computations. The coupled
thermomechanical analysis and material direction optimization reflects the anisotropic Young’s
modulus and thermal stresses present in large-scale polymer deposition. Resultant structures
show how thermal loading influences the optimal topology, and how different penalty values
determine convergence of the design.",,,,,,
"['Torries, Brian', 'DorMohammadi, Saber', 'Abdi, Frank', 'Thompson, Scott', 'Shamsaei, Nima']",2021-11-04T20:07:08Z,2021-11-04T20:07:08Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90018', 'http://dx.doi.org/10.26153/16939']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'topology optimization', 'defects distribution', 'porosity', 'ICME']",Topology Optimization of an Additively Manufactured Beam,Conference paper,https://repositories.lib.utexas.edu//bitstreams/027e0a3c-229b-4589-bbc7-e51f5a04fc28/download,University of Texas at Austin,"This study investigates the application of topological optimization in conjunction with additive
manufacturing (AM) process simulation for fabricating parts that meet strict quality and
performance requirements while also minimizing printed geometry. Integrated Computational
Materials Engineering (ICME) and GENOA 3D commercial software were used to simulate
specimen fabrication and, along with commercial design optimization tools, create an optimized
beam topology for simple loading conditions. Constraints were set in order to support any overhanging material with an appropriate inclination angle. These specimens were fabricated from Ti-6Al-4V using an EOS M290 direct metal laser sintering (DMLS) system with default parameters,
as well as 95%, 90%, and 88% of default laser power in order to reduce the porosity in the overheated areas. Parts were subjected to X-ray CT scanning to quantify part porosity. It was
determined that the process used allowed for the fabrication of specimens with optimized topology
and minimal defects.",,,,,,
"['Menge, Dennis', 'Delfs, Patrick', 'Töws, Marcel', 'Schmid, Hans-Joachim']",2021-11-09T19:58:18Z,2021-11-09T19:58:18Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90148', 'http://dx.doi.org/10.26153/tsw/17069']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['heat transfer', 'topology optimization', 'electronic housing', 'AlSi10Mg', 'selective laser melting']",Topology Optimized Heat Transfer Using the Example of an Electronic Housing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e926114a-2083-4402-9dfd-11e678222c02/download,University of Texas at Austin,"Function integration is a key issue for an efficient and economic usage of Additive
Manufacturing. An efficient heat transfer by topology optimized structures is a rarely considered
approach which will be outlined with an exemplary electronic housing which has been newly
designed. A commercial projector unit, whose electrical components in total produce 38 W, shall
be integrated in the closed housing and passively cooled by natural convection. Topology
optimized structures shall be generated in the inner part of the housing to transfer the heat
homogenously from the projector components to the housing wall while simultaneously
minimizing the mass. At the outside of the housing walls, lattice and rib structures are applied to
increase the effective surface for heat transfer by natural convection and radiation. Furthermore,
the housing geometry is optimized regarding a minimization of support structures to reduce the
post-processing effort. Finally, the housing shall be built of AlSi10Mg by SLM.",,,,,,
"Wasserfall, Florens",2021-11-11T16:26:03Z,2021-11-11T16:26:03Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90236', 'http://dx.doi.org/10.26153/tsw/17157']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['3D printed electronics', 'multi-material manufacturing', 'routing', 'slicing']",Topology-Aware Routing of Electric Wires in FDM-Printed Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1333dab0-4ad7-4a36-9558-a9cb57a29e65/download,University of Texas at Austin,"The direct integration of electric connections into AM-fabricated plastic parts at printing time has
recently attracted increasing attention. To make efficient use of such techniques, appropriate design
and routing software is required. In prior work, we proposed the integration of Surface-Mounted
Devices (SMD) and wiring into a slicing-software for FDM-based processes. This approach allows to consider process parameters, e.g. extrusion width, layer thickness or temperature for each
specific printjob. In this work, we introduce an algorithm for local, topology-aware wire routing.
The trace-width of a printed wire roughly equates the typical extrusion width of FDM-printers and
the pitch of larger SMD-package types. For curved object surfaces and regions with high wire density, linear routing produces a high number of small islands and gaps. To mitigate this effect, we
attempt to align wires with object perimeters and perimeters of already routed wires. A weighted
graph representation is generated from all printable perimeters of each layer and direct connections
between wire waypoints. An A*-based search is then employed to find optimal routes.",,,,,,
"['Jung, Jinho', 'Chen, Yong']",2021-09-30T20:18:54Z,2021-09-30T20:18:54Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88295', 'http://dx.doi.org/10.26153/tsw/15236']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['reverse engineering', 'Wiimote CAD', '3D modeling', 'augmented reality']",Touch-RE: A Touch-based Model Acquiring Method for Personal Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/31494163-9133-47a0-8b21-175dde992d66/download,University of Texas at Austin,"Enabled by additive manufacturing technology, personal manufacturing, if realized, will give
ordinary people control over their physical world by allowing them to personally program its construction.
Currently several pioneering mass customization and personal fabrication applications have been
developed for consumer products, gifts, toy, etc. However, one of the core challenges that are remained to
be addressed for realizing personal manufacturing is the easiness of creating 3D models for additive
manufacturing systems. Current developments in CAD software and reverse engineering are still lacking
on the easiness of usage especially for normal users without much experience. In this paper, we present a
touch-based 3D-shape acquiring method that is easy and intuitive to use. The key technical challenges on
the related hardware and software development are discussed. A testbed system is presented and multiple
examples are given to demonstrate its capability.",,,,,,
"['Araújo, L.J.P.', 'Özcan, E.', 'Atkin, J.A.D.', 'Baumers, M.', 'Tuck, C.', 'Hague, R.']",2021-10-19T20:54:45Z,2021-10-19T20:54:45Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89337,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'packing', 'build volumes', 'benchmarks']",Toward Better Build Volume Packing in Additive Manufacturing: Classification of Existing Problems and Benchmarks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fd3a00dd-5a9a-4fac-abea-b17fc8f6be17/download,University of Texas at Austin,"In many cases, the efficient operation of Additive Manufacturing (AM) technology relies on build volumes
being packed effectively. Packing algorithms have been developed in response to this requirement. The
configuration of AM build volumes is particularly challenging due to the multitude of irregular geometries
encountered and the potential benefits of nesting parts. Currently proposed approaches to address this packing
problem are routinely evaluated on data sets featuring shapes that are not representative of targeted manufacturing
products. This study provides a useful classification of AM build volume packing problems and an overview of
existing benchmarks for the analysis of such problems. Additionally, this paper discusses characteristics of future,
more realistic, benchmarks with the intention of promoting research toward effective and efficient AM build
volume packing being integrated into AM production planning methodologies.",,,,,,
"['Narra, Sneha P.', 'Cunningham, Ross', 'Christiansen, Daniel', 'Beuth, Jack', 'Rollett, Anthony D.']",2021-10-20T21:22:10Z,2021-10-20T21:22:10Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89364,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'process parameters', 'melting', 'grain size', 'Ti-6Al-4V']",Toward Enabling Spatial Control of Ti-6Al-4V Solidification Microstructure in the Electron Beam Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/151a00a7-9d12-44ce-8e0c-96b8d394325f/download,University of Texas at Austin,"In this work, relationships between prior beta grain size in solidified Ti-6Al-4V and melting
process parameters in the Arcam Electron Beam Melting (EBM) process are investigated. Toward
this goal, samples are built on an Arcam S12 machine at Carnegie Mellon University by
specifically varying the Arcam proprietary speed function and beam current over process space
for a variety of test specimens. Optical microscopy is used to measure the prior beta grain widths
and assess the number of prior beta grains present in a melt pool in the raster region of the build.
Results demonstrate that the number of grains across the width of a bead is constant for a fixed
deposition geometry. The resulting understanding of the relationship between primary machine
variables and prior beta grain widths is a key step toward understanding and enabling the spatial
control of as-built microstructure in the EBM process.",,,,,,
"['Sachs, Emanuel', 'Polito, Benjamin', 'Ables, David', 'Cima, Michael', 'Tsuchiya, Hiroyasu', 'Enokido, Yasushi']",2019-09-23T15:34:25Z,2019-09-23T15:34:25Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75938', 'http://dx.doi.org/10.26153/tsw/3037']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Components,Toward Manufacturing of Fine Components by 3D Printing 191,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8956efc2-cac2-4ca0-92c7-daf225897ea9/download,,"Solid Freeform Fabrication has earned its place in the industrial practice of prototyping and is beginning to have an impact in the fabrication of tooling. The next and perhaps greatest opportunity for SFF lies on the direct manufacture of components. This paper will present efforts directed toward the MANUFACTURE IN HIGH QUANTITY of small, precision components by 3D Printing. The primary focus is on ceramic and ceramic/metal components, although all metal components are envisioned as well. The production of small, fine-featured parts presents two opportunities for a new machine architecture. First, the powderbeds required for small parts are themselves small and lightweight. Thus, a machine can be designed where powderbeds move from the layer spreading station to the print station and back again. Multiple powder beds can be in play, taking full advantage of all stations of the machine. The second opportunity is to define the perimeter of the part using vector motions of a nozzle with the interior filled by raster scanning. Such an approach has the advantage that the boundary of the part will be defined as a smooth contour. Moving powderbeds and vector printing are combined in the linear shuttle-type machine for research purposes. Ultimately, a rotary machine is envisioned for high production.",,,,,,
"['Gomez Bonilla, Juan S.', 'Trzenschiok, Holger', 'Lanyi, Franz', 'Schubert, Dirk W.', 'Bück, Andreas', 'Schmidt, Jochen', 'Peukert, Wolfgang']",2021-11-18T16:42:19Z,2021-11-18T16:42:19Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90421', 'http://dx.doi.org/10.26153/tsw/17342']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['plasma enhanced chemical vapor deposition', 'PECVD', 'silica nanoparticles', 'bed coating', 'flow behavior', 'processability', 'polypropylene', 'selective laser sintering']",Toward Modification of Flow Behavior and Processability of Polypropylene Powders in SLS by Fluidized Bed Coating with In-Situ Plasma Produced Silica Nanoparticles,Conference paper,https://repositories.lib.utexas.edu//bitstreams/170ceeaa-18cd-4c1e-b192-069201a18e40/download,University of Texas at Austin,"The processability of selective laser sintering (SLS) powders and the characteristics of the generated parts
depend amongst others on the flowability. To increase the flowability, SLS powders are usually functionalized
with flowing agents. Flowing agents are typically applied by dry particle coating. The optimization of the process
parameters necessary to achieve a homogenous coating avoiding segregation is still empirical. In this contribution,
an alternative process to particle dry coating is presented. This process integrates the synthesis of silica
nanoparticles via plasma enhanced chemical vapor deposition (PECVD) and coating of polymer host particles in
a fluidized bed in a single process. The influence of the treatment time on the packing density and flow behavior
of the powders is investigated. Test specimen are produced to assess the influence of the treatment on the
processability of the powders and the mechanical properties of the produced parts.",,,,,,
"['Yeung, Ho', 'Neira, Jorge']",2024-03-26T22:56:31Z,2024-03-26T22:56:31Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124436', 'https://doi.org/10.26153/tsw/51044']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser bed powder fusion', 'additive manufacturing', 'voxel level control']",Toward Voxel Level Control for Laser Powder Bed Fusion Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6ca02980-4d42-4d59-94c1-bd8cb655d33b/download,University of Texas at Austin,"In the Laser Powder Bed Fusion (LPBF) additive manufacturing (AM) process, a highspeed scanning laser beam is employed to construct components by melting and fusing metal
powder together. While AM is generally characterized as a layer-by-layer technique, LPBF builds
can also be conceptualized on a voxel-by-voxel basis, utilizing a point laser heating source. As a
result, managing the LPBF process at the voxel level – that is, focusing on individual 3D printing
elements or volume pixels – will be highly beneficial. In this study, we will explore the laser
control requirements necessary for achieving voxel-level precision in the LPBF process and
demonstrate these concepts through experiments.",,,,,,
"['Abdullahi, Adnan', 'Kankam, Immanuella', 'Gahloth, Abhay Singh', 'Arora, Bhavya', 'Agarwal, Ankit', 'Eppley, Trevor', 'Salti, Ziyad', 'Goss, Derek', 'Sharma, Raghav', 'Bhate, Dhruv']",2021-11-18T02:06:06Z,2021-11-18T02:06:06Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90407', 'http://dx.doi.org/10.26153/tsw/17328']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'composite', 'carbon fiber', 'micromechanics', 'additive manufacturing', 'modeling']",Towards a Micromechanics Model for Continuous Carbon Fiber Composite 3D Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3e7cd553-98b1-4661-a32c-b9740d542b27/download,University of Texas at Austin,"Material extrusion is transitioning from a technology mainly for rapid prototyping to one that
is increasingly finding use in manufacturing functional parts. Of particular interest in this regard
is the reinforcement of extruded parts with Continuous Carbon Fiber (CCF). However, predicting
the effective properties of 3D printed composite parts presents a unique challenge because of the
strong effects of meso-structure on the mechanical behavior of printed parts. This work aims to
develop a mathematical model that would enable such a prediction of behavior by incorporating
the rule of mixtures commonly used in micromechanics modeling. Results from tensile tests on
composite specimens with varying volume fractions produced from a blend of onyx (nylon and
chopped carbon fiber) and CCF are reported. Volume fractions are varied through a range of
factors including the layers with fiber, the distribution of fiber within layers and the angle of the
fibers relative to the loading direction, though findings suggest that this has no significant influence
on the model itself, and that volume fraction is a sufficient parameter. The predictive ability of the
micromechanics model is put to the test for composite honeycombs under compression, and a wide
discrepancy between model and experimental result is demonstrated, demonstrating the limitations
of such a model and suggesting pathways for improvement.",,,,,,
"['Mai, J.', 'Thistleton, C.', 'Löschke, S.K.', 'Proust, G.', 'Dong, A.']",2021-10-28T22:40:02Z,2021-10-28T22:40:02Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89720,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['wood-plastic composites', 'fused deposition modeling', 'aesthetic', 'perlin noise']","Towards a New Techno-Aesthetic Paradigm: Experiments with Pattern, Texture and Colour in 3D-Printed Wood-Plastic Composites",Conference paper,https://repositories.lib.utexas.edu//bitstreams/ff66de6e-055c-4dc8-9fb8-2f38977f7cd0/download,University of Texas at Austin,"3D printing of wood-plastic composites (WPC) has the potential to create its own
aesthetic paradigm by taking advantage of the possibilities of digital fabrication. This study
explores the process parameters affecting the aesthetic of the resultant 3D printed product using
the commercial wood-plastic composite filament LAYWOO-D3, and printed using a Leapfrog™
Creatr 1.75mm fused deposition modelling (FDM) system. The parameters explored were the
temperature of the printer nozzle of the 3D printer, the velocity of the printer head and the
toolpath of the extruder. These variables were manipulated with algorithms to incorporate key
aesthetic attributes of wood such as the grain pattern, surface texture and colour. Study of these
parameters will allow further insight into the creation of 3D printed wood-plastic composites and
has the potential to forge a positive public perception of composites as a technologically
advanced product that offers a functional and aesthetic alternative to natural wood.",,,,,,
"['Mazzei Capote, G.A.', 'Redmann, A.', 'Koch, C.', 'Rudolph, N.']",2021-11-02T18:17:20Z,2021-11-02T18:17:20Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89856,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'FFF', 'tensile properties']",Towards a Robust Production of FFF End-User Parts with Improved Tensile Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82c519fc-dbd0-492b-a744-505a770dc44e/download,University of Texas at Austin,"The relatively low cost of Fused Filament Fabrication (FFF) printers and wide variety of
materials -spanning multiple functionalities and prices- make this process interesting for
production of functional parts. However, FFF produced objects underperform in terms of
mechanical properties when compared to injection molding. Therefore, a study of tensile
properties of FFF produced parts was conducted according to the ASTM D-638 standard, using a
commercial and an in-house produced ABS filament. Initial tests using commercial ABS revealed
poor reproducibility of results, which were analyzed in detail in this study. This led to designing a
formal bed levelling procedure for the printer, evaluating effects of printer configuration and
material quality as well as exploring modifications to the ASTM test procedure. As a result, test
specimens with properties close to injection molding parts were produced. Therefore, the different
impact factors will be discussed and the new procedures will be presented.",,,,,,
"['Lindemann, Christian', 'Jahnke, Ulrich', 'Reiher, Thomas', 'Koch, Rainer']",2021-10-18T20:37:04Z,2021-10-18T20:37:04Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89237,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'end users', 'part candidates', 'business integration']",Towards a Sustainable and Economic Selection of Part Candidates for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/906475bf-fbed-4f14-9825-c8aa247fdea3/download,University of Texas at Austin,"Additive manufacturing has a high potential for improving time and cost efficiency as well as
functionality of products in many branches. Today potential users struggle with the
integration of this technology in their businesses. The production costs of this technology
often seem too high compared to traditionally manufactured parts and many users seem
disappointed with the performance of the technology. One of the crucial points for bringing
the technology to new users and new industries is the appropriate selection of feasible part
candidates. A systematic selection of parts is crucial for the sustainable and successful use
and integration of additive manufacturing into existing businesses. The selection needs to be
based on technical, economical and strategic aspects. This paper presents a methodology to
help end users to find appropriate part candidates, which are capable of bringing AM into
their businesses. The concept furthermore includes approaches for redesigning current
available parts and helps to estimate the economic implications of the use of the technology.",,,,,,
"['Kerr, C.J.', 'Munguia Valenzuela, J.', 'Nixon-Pearson, O.', 'Forrest, M.', 'Gosling, P.D.']",2023-04-03T15:32:56Z,2023-04-03T15:32:56Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117715', 'http://dx.doi.org/10.26153/tsw/44594']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Polymers', 'Pastes', 'Extrusion', 'UV Curing', 'Processing', 'Large Area Additive Manufacturing', 'Composites', 'Standards', 'Flexural Testing']","Towards an Automated Methodology for Optically Cured, High Thickness Composite Polymer Pastes: An Iso-based Approach for Large Area Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/16514b8e-d950-4ff7-afdc-9d82ac8c8127/download,,"Optically cured polymer composites can offer numerous advantages over thermally-
processed composites. This is especially applicable with large beads generated using Large 
Area Additive Manufacturing (LAAM) extrusion. This paper proposes a low-cost, semi-
automated, off-the-shelf desktop system to quickly and precisely cure 8 mm thick, glass-filled 
(di-)methacrylate composite specimens for three-point flexural testing. In the absence of a 
clear preparation method for specimens of this thickness, we integrate aspects of two existing 
ISO Standards: ISO 178:2019, and ISO 4049:2019, to provide a rapid and reliable basis for 
specimen preparation and flexure testing. We propose two distinct curing strategies and 
compare these in terms of the flexural performance of prepared specimens, and the total cure 
time. Flexural data is critical to understanding the structural performance of light-activated 
composite pastes; and the curing methodology can be applied to potential future technologies 
which involve high-speed in-situ curing, from direct part/feature repair to functional 
production.",,,,,,
"['Dantin, Matthew J.', 'Furr, William M.', 'Priddy, Matthew W.']",2021-11-15T21:04:58Z,2021-11-15T21:04:58Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90271', 'http://dx.doi.org/10.26153/tsw/17192']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'directed energy deposition', 'open-source', 'G-code', 'finite element modeling']","Towards an Open-Source, Preprocessing Framework for Simulating Material Deposition for a Directed Energy Deposition Process",Conference paper,https://repositories.lib.utexas.edu//bitstreams/b8afaca7-2ee4-49b9-8459-0f9b60253c82/download,University of Texas at Austin,"This work focuses on the development of an open-source framework to simulate material
deposition for arbitrary geometries with respect to desired process parameters during a directed
energy deposition (DED) process. This framework allows the flexibility to define the element
activation criteria used in conjunction with Abaqus. A Python script was developed to extract
toolpath coordinates from G-code and implement an element activation sequence that is unique to
a specific CAD drawing. This is important for simulating the additive manufacturing construction
of complex geometries because the thermal history of the component is dependent on laser path,
which has a significant effect on residual stresses and distortion. The results of varying the element
activation criteria are compared with simulated temperature profiles.",,,,,,
"['Urban, James', 'Capps, Nick', 'West, Brian', 'Hartwig, Troy', 'Brown, Ben', 'Landers, Robert', 'Bristow, Douglas', 'Kinzel, Edward']",2021-11-08T21:38:15Z,2021-11-08T21:38:15Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90048', 'http://dx.doi.org/10.26153/tsw/16969']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['defect detection', 'defects', 'fingerprinting', 'modal testing', 'metal parts', 'selective laser melting']","Towards Defect Detection in Metal SLM Parts Using Modal Analysis ""Fingerprinting""",Conference paper,https://repositories.lib.utexas.edu//bitstreams/527b11b1-c3fa-4c35-9958-3d1b7513ae86/download,University of Texas at Austin,"The validation of Additively Manufactured (AM) materials is a difficult and expensive
process because the local engineering properties are a function of the thermal history. The thermal
history varies with the process parameters, as well as the part geometry. This paper presents a case
study using modal testing to identify defects in realistic AM parts. A setup consisting of a
Scanning Laser Doppler Vibrometer (LDV) was used to identify the resonant frequencies for
several geometrically identical parts on a build plate. Parts with suboptimal process parameters
from purposely varying the process parameters, are identified by a shift in the mode peak
frequency. Results from this study are compared to Finite Element Analysis (FEM) models and
generalized for identifying defects in parts created with AM on the basis vibration/modal
“fingerprinting.”",,,,,,
"['Kurfess, Rebecca', 'Saleeby, Kyle', 'Feldhausen, Thomas', 'Fillingim, Blane', 'Hart, A. John', 'Hardt, David']",2023-01-25T14:02:14Z,2023-01-25T14:02:14Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117286', 'http://dx.doi.org/10.26153/tsw/44167']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'support structures', 'porosity']",Towards directed energy deposition of metals using polymer-based supports: porosity of 316L stainless steel deposited on carbon-fiber-reinforced ABS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b28f9f15-eeb8-43e1-9ae7-219e2fb5d143/download,,"Directed energy deposition (DED) is increasingly valuable to many industries because of 
its high deposition rates relative to other metal additive manufacturing processes, but the design 
space of DED is limited. For instance, steep overhangs are difficult or impossible to manufacture. 
Polymer-based support structures could help address this challenge. The viability of DED on 
polymer composite substrates has begun to be explored, specifically with 316L stainless steel on 
carbon-fiber-reinforced ABS substrates. Monolithic metal components can be deposited on the 
polymer, but it was found that gas release during polymer degradation causes porosity due to gas 
entrapment in the metal. An interlayer cooling time was introduced to reduce polymer degradation 
and decrease the porosity due to gas entrapment, but this led to porosity from lack of fusion. The 
results of this work provide insight into process parameter selection and scan strategy development 
to enable the use of polymer support structures in blown-powder DED.",,,,,,
"['Jahn, A.', 'Li, H.', 'Emminghaus, N.', 'Melnyk, T.', 'Hermsdorf, J.', 'Kaierle, S.']",2024-03-27T16:02:01Z,2024-03-27T16:02:01Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124498', 'https://doi.org/10.26153/tsw/51106']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'Ti-6Al-4V', 'laser powder bed fusion', 'gyroids', 'porosity']",Towards experimental process parameter development for Ti-6Al-4V TPMS lattice structures with application to small scale dental implants using micrographs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c23d7d2a-92cb-4390-a464-cdb8c7afb76a/download,University of Texas at Austin,"Ti-6Al-4V is a widely used alloy in implant engineering and lattice structures can be applied to locally
match the stiffness of the implant to the stiffness of bone. Triply periodic minimal surface (TPMS) structures are
popular due to their curved surface, which supports a good manufacturability and osseointegration of the implant.
Tests with different TPMS structures showed a strong interaction between design factors and manufacturing
parameters resulting in the need for individual parameter development. However, to the best of our knowledge,
the most work in the current literature focusses on mechanical and biological examinations of TPMS structures
manufactured with standard parameters. As process parameters influence the structural properties, the optimum
values for further analysis may not have been investigated (e.g., their influence on microstructure and mechanical
properties). In this work, a design of experiments approach is used to develop process parameters. As computer
tomography scans are resource intensive for large scale parameter development, a sparser approach using
micrographs for porosity analysis is introduced. Small structures with unit cell size as small as 1.0 mm are
fabricated on a laser powder bed fusion industrial machine. Our initial studies show that the design factor pore
size is negligible in comparison to wall thickness when optimizing internal porosity.",,,,,,
"['Kniepkamp, Michael', 'Harbig, Jana', 'Seyfert, Christoph', 'Abele, Eberhard']",2021-11-15T22:45:21Z,2021-11-15T22:45:21Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90301', 'http://dx.doi.org/10.26153/tsw/17222']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['layer thickness', 'combination', 'build rates', 'selective laser melting']",Towards High Build Rates: Combining Different Layer Thickness within One Part in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/01dbd4af-e92d-4272-a148-b9b6b0432d06/download,University of Texas at Austin,"Additive manufacturing of metallic parts using powder bed based fusion processes like
selective laser melting is increasingly used in industrial applications. With typical layer thicknesses
of 20 – 40 µm good surface qualities and high geometrical accuracy can be achieved compared to
other AM processes. However, low layer thicknesses are to the detriment of build rates as more
layers are required. Increasing the layer thickness can significantly increase build rates at the cost
of surface quality and accuracy. In this paper a new parameter set for a layer thickness of 60 µm is
developed and combinations of different layer thicknesses within one part are investigated. Thus
increased build rates can be achieved while a high accuracy can be maintained when locally
required. Specimens with combination of different layer thicknesses in various build orientations
are produced and mechanically tested. Micrographs of the layer transitions are examined and
recommendations for their design are given.",,,,,,
"['Yan, Wentao', 'Ge, Wenjun', 'Smith, Jacob', 'Wagner, Gregory', 'Lin, Feng', 'Kam Liu, Wing']",2021-10-19T22:01:42Z,2021-10-19T22:01:42Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89343,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Electron Beam Melting', 'Finite Element Method', 'high quality', 'single track formations', 'distortions']",Towards High-Quality Selective Beam Melting Technologies: Modeling and Experiments of Single Track Formations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bb8e3205-301d-4dc1-a17e-815bb57b01b6/download,University of Texas at Austin,"Additive manufacturing technologies are promising but still not widely used. One major
problem is the unsatisfying quality e.g. surface roughness and dimensional accuracy. The
discontinuous droplets and distortions in single track formations, which influence both surface
roughness and dimensional accuracy, were investigated. The physical mechanisms of the
formations of the droplets and distortions were proposed and the heat transfer simulations based
on the Finite Element Method were established to predict the possibility of the droplet formation
and the magnitude of the distortion. Experiments using Electron Beam Melting were then
conducted to validate the physical and numerical models. The good agreements of the simulated
and experimental results demonstrated that the proposed models are simple and efficient to provide
quantitative predictions of the distortions.",,,,,,
"['Bernardo, Jesse', 'Samavedi, Satyavrata', 'Williams, Christopher B.', 'Morgan, Abby W.']",2021-10-04T20:01:39Z,2021-10-04T20:01:39Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88331', 'http://dx.doi.org/10.26153/tsw/15270']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['tissue scaffold', 'additive manufacturing', 'fused deposition modeling', 'biomimetic mineralization']",Towards Indirect Tissue Scaffold Fabrication via Additive Manufacturing and Hydroxyapatite Mineralization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b23377d-f0de-46c6-91d2-dc29c0488ad4/download,University of Texas at Austin,"Unlike traditional stochastic scaffold fabrication techniques, additive manufacturing (AM) can be used to create
tissue-specific three-dimensional scaffolds with controlled porosity and pore geometry. Directly fabricating
scaffolds through AM methods is limited because of the relatively few biocompatible materials available for
processing in AM machines. To alleviate these material limitations, an indirect fabrication method is proposed.
Specifically, the authors investigate the use of Fused Deposition Modeling to fabricate scaffold patterns of varied
pore size and geometry. The scaffold patterns are then mineralized with a biocompatible ceramic (hydroxyapatite).
A heat treatment is then used to pyrolyze the pattern and to sinter the thin ceramic coating. The result is a
biocompatible ceramic scaffold composed of hollow tubes, which may promote attachment of endothelial cells and
vascularization [1].
In this paper, the authors explore the scaffold pattern fabrication and mineralization processes. Two scaffold
pattern materials are tested [acrylonitrile butadiene styrene (ABS) and investment cast wax (ICW)] to determine
which material is the most appropriate for scaffold mineralization and sintering. While the ICW could not be
thoroughly mineralized despite a sodium hydroxide surface treatment, the ABS patterns were successfully
mineralized following an oxygen plasma surface treatment. A 0.004 mm mineral coating was found on the ABS
patterns that featured a strut offset of 0.3 mm, which is in the range of appropriate pore size for bone tissue
engineering [2].",,,,,,
"['Nettekoven, Alexander', 'Fish, Scott', 'Beaman, Joseph', 'Topcu, Ufuk']",2023-02-09T16:04:24Z,2023-02-09T16:04:24Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117438', 'http://dx.doi.org/10.26153/tsw/44319']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['LPBF', 'SLS', 'SLM', 'laser track', 'pre-processing', 'efficient storage']",Towards Online Monitoring and Data-Driven Control: A Study of Segmentation Algorithms for Laser Powder Bed  Fusion Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de475f04-6b30-4cb0-a2d8-4f9ea8901b16/download,,"An increasing number of laser powder bed fusion machines use off-axis infrared cameras to improve online moni-
toring and data-driven control capabilities. However, there is still a severe lack of algorithmic solutions to properly
process the infrared images from these cameras, which has led to several key limitations: a lack of online moni-
toring capabilities for the laser tracks, insufficient pre-processing of the infrared images for data-driven methods,
and large memory requirements for storing the infrared images. To address these limitations, we study over 30
segmentation algorithms that segment each infrared image into a foreground and background. By evaluating each
algorithm based on its segmentation accuracy, computational speed, and spatter detection characteristics, we iden-
tify promising algorithmic solutions. The identified algorithms can be readily applied to the laser powder bed
fusion machines to address each of the above limitations and thus, significantly improve process control.",,,,,,
"['Williams, Christopher B.', 'Mistree, Farrokh', 'Rosen, David W.']",2020-02-21T14:49:56Z,2020-02-21T14:49:56Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80059', 'http://dx.doi.org/10.26153/tsw/7081']",eng,2005 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Cellular Materials']",Towards the Design of a Layer-Based Additive Manufacturing Process for the Realization of Metal Parts of Designed Mesostructure,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8608f073-4f92-4da0-bf99-d8d088f51b9d/download,,"Low-density cellular materials, metallic bodies with gaseous voids, are a unique class of materials that have
high strength, good energy absorption characteristics, good thermal and acoustic insulation properties, accompanied
by an extremely low mass. Unfortunately, current cellular material manufacturing processes severely limit a
designer’s ability to control the part mesostructure, the material composition, and the part macrostructure.
As such, the authors look towards the use of layer-based additive manufacturing (AM) as a means of providing
the design freedom that is currently absent from cellular material manufacturing processes. Since current metalbased AM techniques do not offer an adequate means of satisfying the unique requirements of cellular materials, the
authors carry out the conceptual design of a new AM process that is dedicated to the manufacture of cellular
materials. Specifically, the authors look to the layer-based additive fabrication of metal oxide powders followed by
post-processing in a reducing atmosphere as a means of fabricating three-dimensional, low-density cellular metal
parts with designed mesostructure. In this paper, the authors detail this conceptual design process and select
working principles that are worthy of further investigation.",,,,,,
"['Smet, M.', 'Li, G.', 'Goossens, L.R.', 'Buls, S.', 'Van Hooreweder, B.']",2024-03-27T16:03:51Z,2024-03-27T16:03:51Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124499', 'https://doi.org/10.26153/tsw/51107']",en,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'lattice production', 'copper', 'additive manufacturing']",TOWARDS THE LIMITS IN COPPER LATTICE PRODUCTION VIA FIBER LASER POWDER BED FUSION,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d0557fe8-a571-4138-b583-586bef40cea1/download,University of Texas at Austin,"Additive manufacturing of copper, by means of Laser Powder Bed Fusion (LPBF), paves the way for
innovation in thermal systems and heat transfer devices. Recent simulations have shown that by interchanging
typical fin designs with more complex structures, an overall improvement in pressure drop and weight can be
obtained while offering the same thermal performance. Here, small-scale lattice structures are especially of
interest for AM as they form a reliable, periodic infill. However, until now, their study has been mainly theoretical.
To analyze these structures in more detail, an in-house built LPBF machine at KU Leuven has been successfully
used to manufacture pure copper parts. Measurements showed a conductivity exceeding 100%IACS, which is the
result of low contamination and low porosity in the as-built material. In this work, the parameter optimization for
thin-walled lattices is discussed, the limitations in terms of minimal feature size are described and physical
mechanisms behind these limitations are uncovered.",,,,,,
"['Hafkamp, Thomas', 'van Baars, Gregor', 'de Jager, Bram', 'Etman, Pascal']",2021-11-02T19:25:02Z,2021-11-02T19:25:02Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89873,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['recoating', 'ceramic-filled resin', 'ceramics', 'vat photopolymerization', 'stereolithography']",A Trade-Off Analysis of Recoating Methods for Vat Photopolymerization of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/79477c5f-81b5-4340-845b-fa114f24de55/download,University of Texas at Austin,"Technical ceramic parts can be produced by curing ceramic-filled resins in the vat photopolymerization (stereolithography) process. Scaling up to larger ceramic product sizes and higher product
quality calls for the integration of more sensing, actuation and closed-loop control solutions while
taking a systems engineering approach. This paper gives a comprehensive overview of methods
to deposit a layer of (ceramic-filled) resin, better known as recoating. The aim of this work is to
perform a trade-off analysis of recoating methods to enable the selection of the method that best
meets the requirements for scaling up the printable object size in the ceramic vat photopolymerization process.",,,,,,
"['Menon, Nandana', 'Mondal, Sudeepta', 'Basak, Amrita']",2023-02-09T15:59:47Z,2023-02-09T15:59:47Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117437', 'http://dx.doi.org/10.26153/tsw/44318']",eng,2022 International Solid Freeform Fabrication Symposium,Open,machine learning,Transferring Process Mapping Knowledge across SS316L and IN718 in Laser Directed Energy Deposition Using  Machine Learning,Conference paper,https://repositories.lib.utexas.edu//bitstreams/193dbadb-817c-44b0-85b7-38b5f9ab8140/download,,"Laser-directed energy deposition additive manufacturing processes have several parameters that 
impact the melt pool properties, which in turn affect the microstructure of the part. Computational 
investigations are regularly implemented; however, these investigations must be repeated for each 
material of interest. In this paper, a transfer learning approach is proposed to address this challenge. 
Using an analytical model, input-output data pairs are generated for a nickel-based alloy, IN718, 
and an iron-based alloy, SS316L. A baseline neural network is trained for SS316L. The capability 
of transfer learning is analyzed with parametric retraining of the percentage of data used and the 
number of retrained layers of the SS316L baseline network on the IN718 data. With just 10% data 
and one hidden layer retrained, accuracies above 90% are observed. The results show that the 
acquired printability knowledge can be transferred across material systems without requiring a 
significant amount of data for a new material system.",,,,,,
"['Gomez, Connie', 'Starly, Binil', 'Shokoufandeh, Ali', 'Sun, Wei']",2020-02-27T21:01:31Z,2020-02-27T21:01:31Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80107', 'http://dx.doi.org/10.26153/tsw/7128']",eng,2006 International Solid Freeform Fabrication Symposium,Open,Computer Aided Tissue Engineering,Transferring Unit Cell Based Tissue Scaffold Design to Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78993294-28e4-4abf-8e19-c98bef1b3fc5/download,,"Designing for the freeform fabrication of heterogeneous tissue scaffold is always a challenge in
Computer Aided Tissue Engineering. The difficulties stem from two major sources: 1)
limitations in current CAD systems to assembly unit cells as building blocks to form complex
tissue scaffolds, and 2) the inability to generate tool paths for freeform fabrication of unit cell
assemblies. To overcome these difficulties, we have developed an abstract model based on
skeletal representation and associated computational methods to assemble unit cells into an
optimized structure. Additionally we have developed a process planning technique based on
internal architecture pattern of unit cells to generate tool paths for freeform fabrication of tissue
scaffold. By modifying our optimization process, we are able to transfer an optimized design to
our fabrication system via our process planning technique.",,,,,,
"['Aggarangsi, Pruk', 'Beuth, Jack L.', 'Gill, David D.']",2020-02-12T15:44:02Z,2020-02-12T15:44:02Z,2004,Mechanical Engineering,,"['https://hdl.handle.net/2152/79942', 'http://dx.doi.org/10.26153/tsw/6968']",eng,2004 International Solid Freeform Fabrication Symposium,Open,Manufacturing Processes,Transient Changes in Melt Pool Size in Laser Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e5f93c4-66bd-409d-bc90-4fa25b7e76b8/download,,,,,,,,
"['Sigl, M.', 'Lutzmann, S.', 'Zaeh, M.F.']",2020-03-02T15:29:30Z,2020-03-02T15:29:30Z,9/14/06,Mechanical Engineering,,"['https://hdl.handle.net/2152/80133', 'http://dx.doi.org/10.26153/tsw/7154']",eng,2006 International Solid Freeform Fabrication Symposium,Open,electron beam,Transient Physical Effects in Electron Beam Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b785571b-a4d1-43a7-b22c-fed23b851ba3/download,,"The extensive use of the electron beam in manufacturing processes like welding or perforating
revealed the high potentials for also using it for solid freeform fabrication. First approaches like
feeding wire into a melt pool have successfully shown the technical feasibility. Among other
features, the electron beam exhibits high scanning speed, high power output, and beam density.
While in laser-based machines the fabrication is working in a stable way, transient physical
effects in the electron beam process can be observed, which still restrict process stability. For
instance, a high power input of the electron beam can result in sudden scattering of the metal
powder. The authors have developed an electron beam freeform fabrication system and examined
the above mentioned effects. Thus, the paper provides methods in order to identify, isolate and
avoid these effects, and to finally realize a reproducible process.",,,,,,
"['Roschli, Alex', 'Borish, Michael', 'White, Liam', 'Adkins, Cameron', 'Atkins, Celeste', 'Barnes, Abigail', 'Post, Brian', 'DiVencenzo, Zac', 'Dwyer, Charlie', 'Rudiak, Gaven', 'Zellers, Brian']",2024-03-26T20:23:20Z,2024-03-26T20:23:20Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124394', 'https://doi.org/10.26153/tsw/51002']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['G-code', '3D printer calibration', 'flowrate', 'feedrate', 'bead width']",Transmitting G-Code with Geometry Commands for Extrusion Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f9dd48c4-3ab0-44dd-bf3c-5c3c451c41b9/download,University of Texas at Austin,"G-code refers to text-based commands used to instruct a 3D printer how to construct an object. G-code
is generated to represent each toolpath during the slicing process. Each toolpath is represented as a list
of points that define the trajectory of the path to be printed. Additional commands are included to define
the motion velocity and extrusion rate, called the feeds and speeds. These toolpaths and commands must
be generated specific to the machine, material, and calibration settings that will be used during the print.
This paper outlines a new approach for the slicing and g-code creation process that eliminates the need
for outputting feeds and speeds in the slicing process. Instead, the slicer outputs g-code that defines the
desired bead geometry as printed. The 3D printer can then read this geometry data and calculate the
necessary feeds and speeds based on internal calibration data to successfully print the object.",,,,,,
"['Niino, Toshiki', 'Yamada, Hidenori']",2020-02-21T14:43:01Z,2020-02-21T14:43:01Z,8/26/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80058', 'http://dx.doi.org/10.26153/tsw/7080']",eng,2005 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,Transparentization of SLS Processed SMMA Copolymer Parts by Infiltrating a Thermosetting Epoxy Resin with Tuned Refractive Index,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9fc67b6c-962c-4213-91cd-3f2e866924d5/download,,"Selective laser sintering is quite advantageous to build complicated tubular
structures such as intake manifolds of automotive engines because of its ability of
building undercut structures without using support ribs. On the other hands, inevitable
opacity of the parts obtained from the process is lowering its advantage when we need to
observe inside of the parts. A technology that can transparentize SLS processed parts by
infiltrating curable resin with tuned refractive index was introduced by the authors in
2004, and in this paper, several modifications are added on material, process
parameters and their control accuracies to improve clarity of obtained parts. As a result
of these modifications, haze of the processed part was reduced by a factor of 40%
reaching the lowest value of 20% through a plate with thickness of 5mm.",,,,,,
"['Weaver, J.M.', 'Patternson, C.']",2021-12-07T18:10:25Z,2021-12-07T18:10:25Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90743', 'http://dx.doi.org/10.26153/tsw/17662']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['TRIZ', 'theory of inventive problem solving', 'design for additive manufacturing']",A Triz-Based Analysis of the Fundamental Limits of Fused Filament Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6a4e6921-e7d7-4e9f-ae0d-4eb591348a87/download,University of Texas at Austin,"Each category of additive manufacturing (AM) has specific fundamental limitations
bounded by the physics and material properties involved. For example, the speed of fused
filament fabrication (FFF) processes is bounded by how quickly thermoplastics can be melted,
deposited, and resolidified while retaining material properties and dimensional accuracy.
Incremental improvements approaching these theoretical limits will continue to occur, but more
radical changes are necessary to completely overcome the current constraints. This paper
considers some of the fundamental limits bounding FFF processes and investigates possible
avenues for future research to overcome these limits. The framework for this analysis is the
“Theory of Inventive Problem Solving” (TRIZ), a formalized problem solving and ideation tool
that generalizes design-specific problems into contradicting engineering parameters, then
suggests universal design principles based on analogy to solutions in other systems and patents.
TRIZ has been used in many fields successfully, including the design of parts to be more
manufacturable through AM, but literature on its application to additive manufacturing processes
themselves is limited. Two case studies are shared demonstrating how TRIZ-based analysis can
lead to radical improvements in FFF and other AM technologies.",,,,,,
"['Subedi, Subodh C.', 'Thoma, Dan J.', 'Suresh, Krishnan']",2021-12-06T23:27:52Z,2021-12-06T23:27:52Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90716', 'http://dx.doi.org/10.26153/tsw/17635']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['truss-type', 'support structures', 'selective laser melting', 'SLM']",Truss-Type Support Structures for SLM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0b5f4dc9-42e1-44a1-a3c2-2d23c62642f5/download,University of Texas at Austin,"Support structures are critical in selective laser melting (SLM) of 3D metal additively
manufactured components. Besides providing structural support, they serve as conduits for
efficient heat dissipation. Support structures heavily influence the printability of a part as
well as its physical and mechanical properties. Commonly used thin walled surface support
structures are reliable, but are difficult to optimize, post-process, and often entrap a significant amount of powder. This paper presents the concept of truss-type surface support
structures for SLM to address these challenges. The proposed structures are easy to optimize and provide better anchorage; further, they do not entrap powder, and are easy to
remove. Experimental results demonstrate the effectiveness of these designs over commonly
used support structures, paving a path towards optimal support structure design for SLM.",,,,,,
"['Pegna, Joseph', 'Messia, David', 'Lee, Woo Ho']",2018-11-28T19:23:39Z,2018-11-28T19:23:39Z,1997,Mechanical Engineering,doi:10.15781/T2348H24F,http://hdl.handle.net/2152/70325,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['Process Control, Rod growth', 'tessellation', '3-D LCVD']",Trussed Structures: FreeForm Fabrication without the Layers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7071b95a-baaa-4f3d-8089-d217dcce27b3/download,,"Recent progress in 3D-LCVD have demonstrated the advantages ofrod micro-fabrication,
both from the point of view of the range of volumetric deposition rates -from 1cl- to 109
cubic micron per second- andfrom the point ofview ofprocessable materials.
A methodforfabricating trussed structures by LCVD ofethylene was tested, based upon scanning
of the laserfocus perpendicular to the laser axis during rod growth. Control of the process is
achieved though feedback ofthe laser power. A closed loop system was designed, which maintains
a constant volumetric deposition rate during growth.
Such capability, combined with previous results by the authors and other researchers in the field,
open a new approach to free form fabrication without layers. Indeed, current results constitute a
proofofconceptfor the fabrication oftruss structures akin to a finite element mesh.",,,,,,
"['Hiller, Jonathan', 'Lipson, Hod']",2020-03-10T16:41:13Z,2020-03-10T16:41:13Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/80228', 'http://dx.doi.org/10.26153/tsw/7247']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Digital materials,Tunable Digital Material Properties of 3D Voxel Printers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/76d4b6de-a233-469c-bc1c-e4447faa7bbf/download,,"Digital materials are composed of many discrete voxels placed in a
massively parallel layer deposition process, as opposed to continuous
(analog) deposition techniques. We explore the material properties
attainable using a voxel-based freeform fabrication process and simulate
how the properties can be tuned for a wide range of applications. By
varying the precision, geometry, and material of the individual voxels, we
obtain continuous control over the density, elastic modulus, CTE,
ductility, and failure mode of the material. Also, we demonstrate the
effects of several hierarchical voxel “microstructures”, resulting in
interesting properties such as negative poisson’s ratio. This implies that
digital materials can exhibit widely varying properties in a single desktop
fabrication process.",,,,,,
"['Teng, Chong', 'Pal, Deepankar', 'Gong, Haijun', 'Stucker, Brent']",2021-10-18T21:45:05Z,2021-10-18T21:45:05Z,2014,Mechanical Engineering,,https://hdl.handle.net/2152/89259,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Metal Laser Sintering', 'thermal fields', 'thermo-mechanical properties', 'two dimensional structure']",A Two Dimensional Analytical Evaluation of Thermal Fields During Metal Laser Sintering Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a13dc913-4415-4525-b216-1a1b5ebbc140/download,University of Texas at Austin,"Metal Laser Sintering (MLS) is a laser based manufacturing technique which is used for
fabrication of parts in a layer-by-layer fashion using fine metal powders. Parts fabricated using
MLS find wide applications in a myriad of areas such as medical, dental, and aerospace industries
due to the availability of high geometric complexity, density, and their thermomechanical
performance in service. A number of computational studies have been conducted in the past to
help understand various underlying mechanisms related to laser melting and reconsolidation in
order to arrive at strategies for better and faster machine architectures and process parameters
combinations which result in stronger and longer-lasting parts.
As intellectual property barriers fall, due to expiring patents and more competitors licensed
to produce machines, the desire to produce better next-generation machines is increasing. In
addition there is a parallel realization that the industry needs better ways to develop new materials
and control schemes for MLS processing. In order to achieve these goals, in this study we will
provide an insight into the various thermo-mechanical phenomena which occur during MLS by
providing a brief update on computational studies in the literature followed by the derivation of an
efficient fully analytical framework for this problem. A two dimensional example is provided
illustrating various aspects of this formulation which will be modified for a full 3 Dimensional
formulation and implementation in the future to achieve the above-mentioned goals.",,,,,,
"['Sassaman, Doug', 'Hall, Peter', 'Fish, Scott', 'Beaman, Joseph']",2021-11-16T14:57:22Z,2021-11-16T14:57:22Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90303', 'http://dx.doi.org/10.26153/tsw/17224']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['window contamination', 'contamination', 'nylon 11', 'selective laser sintering']",Two-Dimensional Characterization of Window Contamination in Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8bddce91-2254-4082-88e5-f2c08684f58e/download,University of Texas at Austin,"Most Laser Sintering machines suffer from an issue where it is hypothesized that hot
gases produced during the laser sintering process collect on the Zinc selenide (ZnSe) window
separating the build chamber from the environment. This contamination has previously been
shown to reduce delivered laser power by up to 10%, and necessitate frequent cleaning and
replacement of the windows. A power meter was constructed in order to perform ex-situ
measurements of laser attenuation at various locations on the window. Identical builds were
performed using fire-retardant nylon 11 on a DTM Sinterstation 2500, and the windows were
measured before and after each build. Results indicate that contamination is not uniform on the
window, and may cause a variation in laser attenuation up to 3.5%±0.25% depending on
scanning location. It is also shown here that the contamination patterns are not repeatable from
build to build, even if performed on the same machine.",,,,,,
"['Chen, Tiebing', 'Zhang, Yuwen']",2019-11-20T16:15:52Z,2019-11-20T16:15:52Z,2003,Mechanical Engineering,,"['https://hdl.handle.net/2152/78470', 'http://dx.doi.org/10.26153/tsw/5555']",eng,2003 International Solid Freeform Fabrication Symposium,Open,Two-Component Metal,Two-Dimensional Modeling of Sintering of a Two-Component Metal Powder Layer on Top of Multiple Sintered Layers with a Moving Gaussian Heat Source,Conference paper,https://repositories.lib.utexas.edu//bitstreams/93bc3964-4b80-4f32-8997-78e07a696fd4/download,,"Selective Laser Sintering (SLS) of metal powder is modeled as a two-dimensional melting
and resolidification of a loose powder layer on top of the sintered metal layers with a moving
heat source. The shrinkage induced by melting is accounted for and the problem is modeled
using a temperature-transforming model. The results indicate that both the moving heat source
intensity and scanning velocity have significant effects on the sintering process. Since the
thermal conductivity of the sintered layer is relatively high compared with that of the loose
powder, higher heat source intensity and lower scanning velocity are needed to achieve complete
melting of the loose powder and bond the current layer to the existing sintered layers. A
parametric study is performed and the best combinations of the processing parameters are
recommended.","Support for this work by the Office of Naval Research under grant number N00014-02-1-
0356 is greatly acknowledged.",,,,,
"['Zhang, Jingwei', 'Li, Wei', 'Liou, Frank', 'Newkirk, Joseph']",2021-11-03T21:01:02Z,2021-11-03T21:01:02Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89933,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['grain growth', 'fusion zone', 'cellular automata-finite element', 'direct metal deposition']",A Two-Dimensional Simulation of Grain Structure Growth Within Substrate and Fusion Zone During Direct Metal Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/5d9145eb-a5e9-41a8-a932-936e3aa86aa3/download,University of Texas at Austin,"In this paper, a predictive model based on a cellular automaton (CA)-finite element (FE)
method has been developed to simulate thermal history and microstructure evolution during
metal solidification for a laser-based additive manufacturing process. The macroscopic FE
calculation that is validated by thermocouple experiment is designed to update the temperature
field and a high cooling rate. A cellular automata-finite element (CAFE) method is developed
to describe grain growth in the fusion zone. In the mesoscopic CA model, heterogeneous
nucleation sites, grain growth orientation and rate, epitaxial growth, remelting of preexisting
grains, metal addition, grain competitive growth, and columnar to equiaxed phenomena were
simulated. The developed “decentered polygon” growth algorithm is appropriate for the non-uniform temperature field. Finally, the single and multiple layer direct metal deposition (DMD)
experiment is conducted to validate the characteristics of grain features in the simulation.",,,,,,
"['Friel, R.J.', 'Harris, R.A.']",2021-10-05T19:26:17Z,2021-10-05T19:26:17Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88417', 'http://dx.doi.org/10.26153/tsw/15356']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['Ultrasonic Additive Manufacturing', 'Loughborough University', 'interlaminar bonding', 'fibre positioning', 'electrical circuitry']",Ultrasonic Additive Manufacturing Research at Loughborough University,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bdfbff3c-8058-4c9e-87f3-1f734e3d591c/download,University of Texas at Austin,"Ultrasonic Additive Manufacturing (UAM) has been subject to research and
investigation at Loughborough University since 2001. In recent years, three particular areas
of significant focus have been:
• The influence of pre-process material texture on interlaminar bonding.
• Secure fibre positioning through laser machined channels.
• Freeform electrical circuitry integration.
This paper details the key findings and a number of conclusions from these work
areas. The results of this work have led to the further research and developmental
applications for the UAM technology.",,,,,,
"['Billah, Kazi Md Masum', 'Coronel, Jose L. Jr.', 'Chacon, Sarah', 'Wicker, Ryan B.', 'Espalin, David']",2021-11-16T16:42:15Z,2021-11-16T16:42:15Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90341', 'http://dx.doi.org/10.26153/tsw/17262']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic embedding', 'carbon fiber', 'polycarbonate', 'thermoplastics', '3D printing']",Ultrasonic Embedding of Continuous Carbon Fiber into 3D printed Thermoplastic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa53ed07-3902-452b-afc4-142435aceab2/download,University of Texas at Austin,"A novel multimaterial fabrication process was developed to embed continuous bundles of
carbon fiber (CF) into polycarbonate (PC) substrates using ultrasonic energy. Continuous CF
possesses superior reinforcement properties compared to that of chopped or short fibers. In this
research, dry continuous CF bundles were impregnated with a PC solution prior to embedding.
Three printing raster orientations were studied (0°, 45°, and 90°), where three layers of CCF were
embedded within each test specimen. Characterizations including tensile, flexural, and dynamic
mechanical analysis were carried out to investigate reinforcement related properties. Results
showed an increase in ultimate tensile strength between neat PC (37 MPa) and CF reinforced
specimens (141 MPa). An automated ultrasonic embedding process allowed for the selective
deposition of CF, regardless of the raster orientation. Future development of continuous CF
reinforced parts could enable smart part fabrication, with applications in structural health
monitoring, microwave shielding, and thermal management.",,,,,,
"['Halloran, John W.', 'Griffith, Michelle L.']",2018-10-03T18:38:29Z,2018-10-03T18:38:29Z,1994,Mechanical Engineering,doi:10.15781/T2599ZM4Q,http://hdl.handle.net/2152/68676,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['ceramic green bodies', 'alumina', 'stereolithography']",Ultraviolet Curing of Highly Loaded Ceramic Suspensions for Stereolithography of Ceramics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eff34e04-c6dc-42e7-b119-ed38258610cc/download,,"Ceramic green bodies can be created using stereolithography methods where a ceramic slip
consisting of 45-55 vlo ceramic powder is dispersed within an ultraviolet-curable aqueous
acrylamide solution. Two ceramic materials were investigated: silica [Si02] for investment casting
purposes, and alumina [AI203] for structural parts. After mixing the powders in the curable
solution, the ceramic slip is tape cast onto a substrate for cure under a high intensity ultraviolet
lamp (220-450 nm) at different exposure times. The materials systems were evaluated at different
solids loadings (10-50 v/o) for cure thickness and viscosity control. Silica had a cure depth of 330
f.lm at a solids loading of 55 vlo, and at 50 vlo, alumina had a cure depth of 300 f.lm.
Preliminary work utilizing scattering theory revealed the cure depth is controlled by the
particle size and the refractive index difference between the ceramic and ultraviolet solution. The
refractive index difference is the dominating factor. Two particle size distributions of alumina were
used to more accurately determine the effect of particle size.",,,,,,
"['Francis, Jomy', 'Sparks, Todd E.', 'Liou, Frank']",2021-09-29T22:25:36Z,2021-09-29T22:25:36Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88220', 'http://dx.doi.org/10.26153/tsw/15161']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['Laser Aided Manufacturing Process', 'laser deposition', 'scallop heights', 'surface finish manufacturing']",Uncertainty Analysis in Laser Deposition Finish Machining Operations,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d71dc882-1693-46c1-9de6-cc300f9d3021/download,University of Texas at Austin,"The Laser Aided Manufacturing Process (LAMP) from Missouri S&T is a laser based
metals rapid manufacturing process that uses machining to improve the final part's surface finish.
When free-form machining, the absence of enough deposited material results in inconsistent
scallop heights which result in poor surface finish or incorrect geometry in the final part. This
paper investigates a probabilistic approach to various uncertainties involved in the deposition and
subsequent machining of an arbitrary part. Furthermore, this paper analyses the machine errors
which makes the response of Scallop Height to exceed the predefined maximum scallop height
when traveling along the tool path interval distance. Tackling these problems allows us to
achieve the final part shape with higher accuracy.",,,,,,
"Yasa, Evren",2021-11-10T22:54:33Z,2021-11-10T22:54:33Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90200', 'http://dx.doi.org/10.26153/tsw/17121']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['metallic material', 'selective laser melting', 'additive manufacturing', 'industrial application', 'research & development']",Understanding Adopting Selective Laser Melting of Metallic Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6179f683-28be-4821-97d1-1c6012779813/download,University of Texas at Austin,"Additive manufacturing, considered as the future of manufacturing or the new industrial
revolution, presents many advantages over conventional manufacturing. These include
manufacturing integrated parts, eliminating joining processes, shortening lead times from design
to testing, lightweight structures, being able to produce very complex geometries at almost no
added cost, etc. Therefore, many industrial sectors such as aerospace, defense, biomedical and
automotive, are getting more excited about adopting these technologies into their production lines.
However, the shortage of experienced personnel in the field of Additive Manufacturing may make
the transition period difficult and troublesome. Since AM technologies are rather new and
immature compared to conventional manufacturing, many issues in terms of safety, environment,
materials, process development, design guidelines as well as testing and validation arise. This paper
will address and review lessons learned as a result of implementing selective laser melting for
industrial applications as well as for research and development purposes so that this valuable
outcome can be used as a guideline by beginners in this field.",,,,,,
"['Khoshkhoo, Ali', 'Carrano, Andres L.', 'Blersch, David M.', 'Ghaednia, Hamid', 'Kardel, Kamran']",2021-11-04T20:56:51Z,2021-11-04T20:56:51Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90026', 'http://dx.doi.org/10.26153/16947']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'reverse engineering', 'surface metrology', 'topograhy', 'natural surfaces', 'benthic algae']",Understanding and Engineering of Natural Surfaces with Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f741148f-7efc-47b1-9e58-ee2b9060c6e0/download,University of Texas at Austin,"Benthic algae systems that attach to substrata have been shown effective in water pollution
remediation and biomass production, but yields are limited by attachment preferences in wild
cultivars. This work seeks to uncover the surface topography preferences for algal attachment by
reproducing natural surface topographies using additive manufacturing. To date, no other research
efforts have taken advantage of using additive manufacturing to reverse engineer the
characteristics of natural surfaces for enhancement of the attachment preferences of certain
periphyton species towards substrata topography. Natural rocks and surfaces with attached
biofilms were retrieved from streams, scanned with optical profilometry, and the surface
characteristics were analyzed. A material jetting process is used to additively manufacture the
surfaces, followed by optical profilometry to validate the resultant topography. The results show
that certain texture parameters (e.g., Smr, Sa, and Sv) are significant in affecting the biomass
adhesion of specific algal communities.",,,,,,
"['Wörz, A.', 'Drummer, D.']",2021-11-11T16:06:05Z,2021-11-11T16:06:05Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90229', 'http://dx.doi.org/10.26153/tsw/17150']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'hatching', 'mechanical behavior', 'polyamide 12']",Understanding Hatch-Dependent Part Properties in SLS,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3b754921-c6d8-4636-8e37-111cae5ff217/download,University of Texas at Austin,"Selective laser sintering of polymers (SLS) is on the verge from pure prototyping to producing
individualized complex parts for series application. As the parts are generated layer-wise and
the influence of process-parameters as well as part orientations are well-known, the aim of the
paper is to point out the influence of the layer-wise manufacturing in dependence of the hatching
strategy on the resulting part properties as these are constant process-steps. Therefore, tensile
bars with different number of layers but constant layer-thickness were produced using different
hatching strategies and investigated depending density, surface roughness and mechanical
properties. The results showed a strong increase of the mechanical properties, ductile breaking
behavior and part density as well as decreasing surface roughness with higher layer numbers as
well as the hatching strategies. Therefore, the results point out significant interaction between
constant process steps and resulting part properties.",,,,,,
"['Lavin, J.M.', 'Keicher, D.M.', 'Whetten, S.R.', 'Moore, P.B.', 'Mani, S.S.']",2021-10-27T21:47:32Z,2021-10-27T21:47:32Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89626,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['defects', 'polyimide films', 'aerosol based printing']",Understanding Sources of Defects in Polyimide Films Using Aerosol Based Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7bd3d21f-40a0-4c4d-baa1-c73641bc8d77/download,University of Texas at Austin,"A study of the sources of defects in films of commercially available polyamic acid
fabricated using aerosol based printing was carried out. Printing was conducted using a Sono-Tek spray nozzle on multi-modular Direct Write Additive Manufacturing System. The driving
force behind this work stemmed from the need to form smooth, defect free films to be used in
electronic components. While numerous process conditions give rise to defects such as the
obvious substrate cleanliness, efforts here focused on the more subtle conditions such as
deposition temperature, deposition speed, nozzle height from the substrate and cure temperature.
The results of this study led to the identification of the most critical source of defects and to a set
of optimal process conditions in the printing of polyimide films using aerosol based printing.",,,,,,
"['Mao, Qing', 'Coutris, Nicole', 'Gibert, James', 'Fadel, Georges']",2021-10-19T17:55:59Z,2021-10-19T17:55:59Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89310,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['Ultrasonic Additive Manufacturing', 'plasticity', 'heat transfer', 'friction', 'lump parameter models']",Understanding the Dynamics of Ultrasonic Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fa396778-2b63-4a82-844e-abe00be0c0fb/download,University of Texas at Austin,"Ultrasonic Additive Manufacturing (UAM) is an additive manufacturing technique that uses
ultrasound to merge metal foils (150 µm thick, 24 mm wide) layer by layer to fabricate three-dimensional bodies. As new layers are deposited and the height-to-width ratio of the built feature
changes, the dynamics of UAM changes accordingly. Prior research suggested the existence of a
limit for the height-to-width ratio. Above this limit, additional layers fail to bond because the
built feature reaches its resonance frequency. Specifically, the bond failure is affected by the lack
of plastic shear deformation between two foils which is essential to the generation of true
metallic bonds. As the height-to-width ratio falls in the critical range, the built feature becomes
resonant under the high-frequency excitations (20 kHz) of the sonotrode, leading to large-amplitude oscillations matching those of the sonotrode, and resulting in reduction of differential
motion and therefore plastic shear deformation between the foils. In order to develop a model
incorporating plasticity, heat transfer, and friction to study UAM, 2-D and 3-D lump parameter
models consisting of mass-spring networks are proposed to study the dynamics of the elastic part
of the built feature. The models are established such that they preserve the modal parameters of
the built feature in free vibration. The lumped parameter models are validated by comparing their
modal predictions with those from 2-D and 3-D finite element models. The lumped parameter
model will be coupled with a 3-D finite element model to describe an elasto-plastic bonding
layer introducing the friction and thermal aspects of UAM. By examining the deformation of the
bonding layer under the combined effects of the excitation of the sonotrode and the vibration of
the built feature, the bond failure due to geometry change of the built feature will be better
understood and quantified in the future.",,,,,,
"['Wörz, A.', 'Wudy, K.', 'Drummer, D.']",2021-11-18T01:46:36Z,2021-11-18T01:46:36Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90399', 'http://dx.doi.org/10.26153/tsw/17320']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['tensile bars', 'layer amounts', 'energy densities', 'mechanical properties', 'roughness', 'density', 'particle melt', 'PA12', 'selective laser sintering']",Understanding the Influence of Energy-Density of the Layer Dependent Part Properties in Laser-Sintering of PA12,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1dc73f27-b423-435d-b450-d83eefb03ab1/download,University of Texas at Austin,"As the demand for individualization and complex parts is continuously growing, laser-sintering of
polymers is on the edge from a pure prototyping technology to manufacturing parts for applications in series
production. The influences on resulting parts and layer depending part properties are well known in the
literature but the understanding of the interaction between process parameters and layer dependent properties
is missing and limiting the dimensioning. Within this study, tensile bars with different amounts of layers and
energy densities were produced and investigated for the resulting mechanical properties, roughness, density
and the degree of particle melt. The results showed a strong interaction between the energy density and amount
of layers, which results in differences in the fracture behavior as well as the mechanical properties. Therefore,
the presented results enable the prediction of necessary part thickness for dimensioning thin parts with laser-sintering.",,,,,,
"['Pavan, Michele', 'Craeghs, Tom', 'Kruth, Jean-Pierre', 'Dewulf, Wim']",2021-10-28T15:13:42Z,2021-10-28T15:13:42Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89660,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['x-rary computed tomography', 'laser sintering', 'porosity', 'microscale level']",Understanding the Laser Sintering of Polymers at Microscale Level by Using X-Ray Computed Tomography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c264394d-42e7-47d4-ae39-a343d3925fcd/download,University of Texas at Austin,"Literature reports on many cases where X-ray Computed Tomography (CT) has been used to
measure the porosity of laser sintered (LS) polymeric parts, in order to characterize the process
parameters’ influence on their density. However, this approach implies to perform a CT scan
for each parameter set being assessed, making the evaluation very costly and time consuming.
Moreover, this approach does not provide useful information about the coalescence steps of the
process and the local variation of the powder packing density which happen at the microscale
level, namely at dimensions comparable to the layer thickness used during the process. This
work presents a new CT-based approach which allows to assess at the microscale the variation
of the sintering conditions for several scanning strategies at the same time. The study focuses
on PA12 powder, but the proposed approach is general and can potentially be applied to every
laser sinterable polymeric powder.",,,,,,
"['Gockel, Joy', 'Beuth, Jack']",2021-10-11T21:57:33Z,2021-10-11T21:57:33Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88657', 'http://dx.doi.org/10.26153/tsw/15591']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['direct metal additive manufacturing', 'additive manufacturing', 'process mapping', 'metal deposition', 'Ti-6Al-4V', 'melt pool geometry', 'microstructure']",Understanding Ti-6Al-4V Microstructure Control in Additive Manufacturing via Process Maps,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3c9fff6-8405-49eb-bbee-cd14f7cb9ff4/download,University of Texas at Austin,"In direct metal additive manufacturing, the ability to predict and control as-deposited
microstructure can reduce the need for post-processing and speed up the qualification process.
In this work, a microstructure process map is presented for deposition of single beads of Ti-6Al4V using an electron beam wire feed process. Further, comparison with a previously developed
process map for melt pool geometry control demonstrates that indirect control of Ti-6Al-4V
solidification microstructure (prior beta grain size and morphology) is possible through direct,
real time melt pool dimension control. These approaches for microstructure prediction and
control can be extended to additional additive processes such as electron beam powder bed
processes.",,,,,,
"['Muhammad, Muztahid', 'Soman, Sajith', 'Ahmad, Nabeel', 'Wells, Douglas N.', 'Shao, Shuai', 'Shamsaei, Nima']",2024-03-26T16:51:38Z,2024-03-26T16:51:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124370', 'https://doi.org/10.26153/tsw/50978']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'Inconel 718', 'facet', 'NASGRO', 'fatigue life prediction']",UNIAXIAL FATIGUE BEHAVIOR AND LIFE PREDICTION OF ADDITIVELY MANUFACTURED INCONEL 718 WITH DIFFERENT GRAIN MORPHOLOGY,Conference paper,https://repositories.lib.utexas.edu//bitstreams/957620d6-c100-4d43-9a2c-61098268a8c7/download,University of Texas at Austin,"Understanding the fatigue behavior and failure mechanisms is essential for qualifying and standardizing
additively manufactured metallic components. This study investigates the uniaxial fatigue behavior and failure
mechanisms of laser powder bed fused (L-PBF) Inconel 718 (IN718) specimens with different grain sizes
obtained by altering the process parameters and heat treatment. Uniaxial, fully-reversed strain-controlled fatigue
tests were conducted on specimens with machined and polished surface conditions. Microstructural analysis and
fractography using a scanning electron microscope were performed to measure the sizes of grains and facets.
Fatigue cracks were initiated at the persistent slip bands near or at the surfaces rather than process-induced
volumetric defects in all cases. The fatigue behavior of L-PBF IN718 specimens was correlated with the sizes of
grains and facets. Fatigue life estimation incorporating the NASGRO equation and √𝑎𝑟𝑒𝑎 of the grain sizes was
performed and shown to predict fatigue life within scatter bands of five.",,,,,,
"['Aguilera, E.', 'Bailey, C.', 'Espalin, D.', 'MacDonald, E.', 'Wicker, R.']",2021-10-26T18:07:47Z,2021-10-26T18:07:47Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89545,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', '3D printing', 'electronics', 'automation', 'software']",Unified Software for Multi-Functional G-Code: A Method for Implementing Multi-Technology Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c023c093-d16c-4eac-9d45-fb1ca8ed18bb/download,University of Texas at Austin,"Additive manufacturing (AM) began a manufacturing revolution moving industrial
production into consumer homes. With interest shifting toward multi-functional parts fabricated
through AM technologies, multi-functional fabrication systems are now being developed.
Merging different manufacturing technologies into a single machine is a challenge, but ongoing
research in the development of multi-technology systems has shown promise. The software and
automation aspects of multi-technology systems are being developed in unison. This paper
explores the challenges and approaches to developing software that interfaces with multifunctional
CADs and creates files for direct use in multi-technology AM machines.",,,,,,
"['Andersen, S.A.', 'Meinert, K.Æ.', 'Kjer, M.B.', 'Nadimpalli, V.K.', 'Pedersen, D.B.']",2023-04-03T15:56:25Z,2023-04-03T15:56:25Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117721', 'http://dx.doi.org/10.26153/tsw/44600']",eng,2022 International Solid Freeform Fabrication Symposium,Open,powder bed fusion,A Unified System Controller for Open-Source Powder Bed Fusion Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/30a0ba89-d515-45c1-8fc4-a02607ebaf13/download,,"This paper presents an open-architecture systems controller for laser powder-bed fusion 
(LPBF). The controller gives the operator direct low-level hardware control, and thereby bridges 
the gap, between system and researcher, often invoked by the proprietary nature of commercial 
LPBF systems. As part of the open-source framework, the bespoke controller provides an open and 
customizable way of controlling the governing subsystems, e.g., scanner (XY2-100), laser, gas 
flow, and motorized actuation. Furthermore, the unified system controller was designed to retrieve 
feedback from the scanner and designated process sensors. Utilizing the process feedback the uni-
fied system controller demonstrates its capabilities to support both open and closed-loop control 
routines. The embedded firmware and custom circuitry allow the unified systems controller to serve 
as a versatile controller for PBF systems, and a powerful tool when investigating and coupling 
process effects to system behavior.",,,,,,
"['Cook, D.', 'Newbauer, S.', 'Leslie, A.', 'Gervasi, V.', 'Kumpaty, S.']",2021-10-05T15:55:20Z,2021-10-05T15:55:20Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88399', 'http://dx.doi.org/10.26153/tsw/15338']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'thermal conductivity', 'ankle-foot orthosis', 'wearable medical devices', 'unit cells']",Unit-Cell-Based Custom Thermal Management through Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2071ff15-94cc-4401-9179-32176d0566c7/download,University of Texas at Austin,"Using previously-defined effective thermal conductivities for structural unit cells, a
custom thermal-management structure has been developed for a powered ankle-foot orthosis.
The structure provides the requisite personal safety for wearable medical devices. Minimal mass
was achieved through the employment of these unit cells. Fabrication of the resultant structure is
made practical by additive manufacturing. Results of the virtual testing are reported, as well as
the preliminary results of an energy-based comparative-performance analysis of natural versus
forced convection. Future work includes the integration of phase-change materials and
thermoelectric generators.",,,,,,
"['Tang, Yunlong', 'Xiong, Yi', 'Park, Sang-in', 'Rosen, David W.']",2021-11-18T16:59:16Z,2021-11-18T16:59:16Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90428', 'http://dx.doi.org/10.26153/tsw/17349']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['material template', 'multiscale design', 'multiscale modeling', 'additive manufacturing']",A Universal Material Template for Multiscale Design and Modeling of Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/de06ec77-4f8f-49c3-824e-0b8533d79202/download,University of Texas at Austin,"In this paper, a universal material template is developed to digitally describe the
materials with spatially distributed compositions and microstructures for multiscale design and
modeling of additive manufacturing processes. The developed template is organized in the
form of a multi-level hierarchical structure. The root node of a material template contains four
sub-nodes. They are “descriptors list”, “constituent materials”, “position information” and
“primitive information”. The format of each sub-node has been given in this paper to help users
to establish a standardized description of microstructures of materials. To validate the
effectiveness of the proposed template, the microstructures of two different types of commonly
used materials in additive manufacturing processes are reconstructed from the pre-defined
material templates. The results show the developed material template can accurately and
precisely control the microstructures of materials. Based on the developed material template,
the multiscale heterogeneous modeling method can be developed in the future.",,,,,,
"['Lang, Andrew', 'Ortiz Rios, Cesar', 'Newkirk, Joseph', 'Landers, Robert G.', 'Castle, James', 'Bristow, Douglas A.']",2021-12-01T22:35:54Z,2021-12-01T22:35:54Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90641', 'http://dx.doi.org/10.26153/tsw/17560']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['defects', '2D SEM', 'XCT', 'X-ray CT', 'laser powder bed fusion']",Unsupervised Defect Classification of 2D SEM and 3D X-Ray CT Images from Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e0f1f79d-52b1-4979-9128-e627e4c95a96/download,University of Texas at Austin,"This work discusses a method to classify defects in laser powder bed fusion using 2D
images of layer samples taken by Scanning Electron Microscope (SEM) and 3D image stacks of a
full part by X-Ray Computed Tomography (XCT). Images using SEM are taken of a sampled layer
in a printed part and unsupervised classification of defects in the SEM images is performed with
Otsu’s thresholding method, K-means classification, and the Robust Automatic Threshold
Selection algorithm. The performance of the classifiers, measured against human-generated
ground truth defect labels, is improved by registering and fusing multiple SEM images taken under
different settings and detector locations. Otsu’s method is shown to be the best classifier for the
3D XCT dataset. Finally, the 2D sample is located in the 3D XCT array and the reliability of the
3D defect classification technique is validated.",,,,,,
"['Ziegler, S.', 'Schleifenbaum, J.H.']",2024-03-27T03:22:37Z,2024-03-27T03:22:37Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124463', 'https://doi.org/10.26153/tsw/51071']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'trend analysis', 'market intelligence', 'text mining']","Usage of Unconventional Data Sources for Market Intelligence (MI) in the Field of Additive Manufacturing (AM) - Expert Networks, Technology Territories and Trends",Conference paper,https://repositories.lib.utexas.edu//bitstreams/9b12bad9-d4e6-425d-8fca-2be6d1cc7f32/download,University of Texas at Austin,"The geographic expansion of the markets for AM increasingly confronts companies with greater
competitiveness due to the globalization. In addition, market participants are facing rapid changes in the business
environment - due to new information and communication technologies. Companies only have a chance to hold
their market position if they quickly adopt market changes. Therefore, the decision-making process needs to be
accelerated by on-demand information provision. MI offers one possibility to meet these requirements, but
typically based on external unstructured data for market and competitive evaluation, which makes it cost and time
consuming. A specific investigation of such data sources related to MI for systematic use within the AM markets
is being carried out. For this purpose, different data sources (e.g. LinkedIn) will be identified, analysed with focus
on information synthesis using text mining and their suitability for the evaluation of expert networks, technology
territories and trends be presented.",,,,,,
"['Wang, Jenny', 'Jariwala, Amit', 'Rosen, David']",2023-01-27T17:39:57Z,2023-01-27T17:39:57Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117342', 'http://dx.doi.org/10.26153/tsw/44223']",eng,2022 International Solid Freeform Fabrication Symposium,Open,stereolithography,Use of a Fluid Interface to Reduce Support Structures in Top-Down Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e995aa91-7b19-41cb-b217-c2a5a3653b21/download,,"Stereolithography (SLA) is a vat photopolymerization additive manufacturing process 
which utilizes ultraviolet (UV) light energy to cure resin layer-by-layer to build parts. The 
fabrication of overhanging geometry in SLA typically requires sacrificial support structures. 
Printing supports increases fabrication time and material usage, and their removal prolongs the 
post-processing and has a detrimental effect on the surface quality of the final part. This study 
investigates a top-down mask projection SLA system in which a fluid of similar density to the 
cured resin is used to support the part during fabrication. The buoyant force of the displaced fluid 
counteracts the gravitational force the part experiences, thus reducing the need for support 
structures in overhangs. The overall system design is presented, and a first-order analytical model 
of part deformation resulting from internal stresses and buoyant and gravitational forces is 
proposed.",,,,,,
"['Hantke, N.', 'Grimm, T.', 'Sehrt, J.T.']",2024-03-26T22:58:12Z,2024-03-26T22:58:12Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124437', 'https://doi.org/10.26153/tsw/51045']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['powder-bed fusion', 'laser beam', 'vibration', 'metal', 'additive manufacturing']",USE OF A VIBRATING BUILD PLATFORM DURING POWDER-BED FUSION OF METALS USING A LASER BEAM,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d050ab25-f8e5-47bf-8f97-7888a4928b34/download,University of Texas at Austin,"Powder-bed fusion of metals using a laser beam (PBF-LB/M) is an additive manufacturing
technique with rising interest in industry and academia. One major topic of current research is to
optimize the performance of parts manufactured by PBF-LB/M. The use of vibrations during the
solidification of metals to improve their mechanical properties is well-known for metal casting and
directed energy deposition. In this work, a vibrating build platform was used during the PBF-LB/M
process to influence the microstructure of parts. Analyses show an increase in sample hardness by
up to 12.3 % for the same process parameters. Especially for process parameters that produce parts
with lower relative densities, vibrations have an influence on part density. With an increase in part
density, this effect gets less pronounced.",,,,,,
"['Fox, Luke', 'Ellis, Adam', 'Hopkinson, Neil']",2021-10-19T21:30:49Z,2021-10-19T21:30:49Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89342,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['high speed sintering', 'ink', 'supply chain']",Use of an Alternative Ink in the High Speed Sintering Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e20a708b-f39e-4a94-8605-566d631fc91d/download,University of Texas at Austin,"High Speed Sintering is a polymer Additive Manufacturing process, which builds parts
by the use of inkjet printing and infrared lamp technology, as opposed to lasers and optics used
in Laser Sintering. For High Speed Sintering to be a viable method to build fast moving
consumer goods the ability to use different inks is critical. This research investigated the effects
of using two separate inks in the High Speed Sintering process. This work shows it is possible
to use inks from different suppliers, which opens up a wider supply chain.",,,,,,
"['Yang, Li', ""O'Neil, Chris"", 'Wu, Yan']",2021-11-08T21:34:18Z,2021-11-08T21:34:18Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90047', 'http://dx.doi.org/10.26153/tsw/16968']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['electropolishing', 'surface treatment', 'powder bed fusion', 'superalloy', 'IN718', 'additive manufacturing']",The Use of Electropolishing Surface Treatment on IN718 Parts Fabricated by Laser Powder Bed Fusion Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f7cf3f9-853a-4f95-ad99-5358ad9c8ffc/download,University of Texas at Austin,"In various applications of additively manufactured Ni-based superalloys, high surface
finish quality is required. In this work, electropolishing surface treatment with anhydrous
electrolyte solution was employed to improve the surface quality of the IN718 parts fabricated by
laser powder bed fusion process. Various process parameters including electropolishing voltage,
temperature, electrolyte spacing and electrolyte flow speed were investigated for their effect on
the improvement of surface roughness characteristics. In addition, the effect of electrolyte flow
uniformity on the surface quality deviation was investigated. The results provided additional
insights to the recently proposed polishing methods proposed by the same group, which clearly
indicates the potential benefit of introducing highly regulated electrolyte flow in the polishing of
AM metal parts.",,,,,,
"['Purser, Molly', 'Cansizoglu, Omer', 'Haslauer, Carla', 'Harrysson, Ola L. A.', 'Loboa, Elizabeth']",2020-03-10T15:26:28Z,2020-03-10T15:26:28Z,9/4/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80216', 'http://dx.doi.org/10.26153/tsw/7235']",eng,2007 International Solid Freeform Fabrication Symposium,Open,polycaprolactone,The Use of Layered Freeform Fabrication Technologies to Produce Tissue Engineering Scaffolds for Skull Patches,Conference paper,https://repositories.lib.utexas.edu//bitstreams/10381f3e-2e2b-486e-afb5-7e5d9d1af20d/download,,"Congenital skull defects in infants are difficult to correct using metal plates due to the growth of
the skull. Tissue engineering of bone patches could be the answer to help such patients. Custom
scaffolds have been designed based on Computed Tomography (CT) images of the patient’s
skull. An in-house developed single screw extruder, casting and a commercial laser cutter has
been evaluated in the fabrication of pure polycaprolactone (PCL) scaffolds as well as PCL mixed
with hydroxyapatite (HA) scaffolds. Evaluation criteria for each process included the ability to
maintain an optimal pore size for cells to proliferate, inclusion of micro surface properties for
cell adhesion, incorporation of hydroxyapatite, and ability to maintain desired shape. The
mechanical properties of the fabricated scaffolds will be presented in this paper as well as initial
cell seeding results with human adipose-derived adult stem (hADAS) cells.",,,,,,
"['Sager, Benay', 'Rosen, David W.']",2020-02-21T20:35:31Z,2020-02-21T20:35:31Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80070', 'http://dx.doi.org/10.26153/tsw/7091']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Stereolithography,Use of Parameter Estimation for Stereolithography Surface Finish Improvement,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dba92737-bada-4fd2-b95e-4de23e7007cc/download,,"In order to improve Stereolithography (SLA) surface finish, a systematic approach based on
estimation of process parameters is needed. In this paper, the exposure on a desired SLA build
surface is formulated as a function of process parameters. The deviation of exposure on this
surface from the critical exposure, which is the threshold that determines curing in the SLA
process, is formulated using least squares minimization. By applying inverse design techniques,
SLA process parameters that satisfy this least squares minimization are determined. Application
of parameter estimation formulation to important SLA geometries is presented and the results,
including surface finish improvement, are discussed.",,,,,,
"['Rybalcenko, Konstantin', 'Gaio, André', 'Folgar, Luis', 'Crabtree, Joseph']",2021-11-30T20:40:27Z,2021-11-30T20:40:27Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90539', 'http://dx.doi.org/10.26153/tsw/17458']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'measuring instrument', 'part surfaces', 'automation', 'in-process optics']",The Use of Smart In-Process Optical Measuring Instrument for the Automation of Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/50a21580-c718-4bea-bfb1-a98eb659fe22/download,University of Texas at Austin,,,This paper presents a novel measuring instrument for part surfaces with millimetre- to micrometre-sized features.,,,,
"['Rybalcenko, Konstantin', 'Gaio, André', 'Folgar, Luis', 'Crabtree, Joseph']",2021-11-18T17:54:27Z,2021-11-18T17:54:27Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90447', 'http://dx.doi.org/10.26153/tsw/17368']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['in-process optical measuring', 'measuring instrument', 'automation', 'additive manufacturing']",The Use of Smart In-Process Optical Measuring Instrument for the Automation of Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8523b474-2ecd-4ba4-8297-1e15da2c796d/download,University of Texas at Austin,,,This paper presents a novel measuring instrument for part surfaces with millimetre- to micrometre-sized features.,,,,
"['Gilman, Charles R.', 'Rock, Stephen J.']",2018-11-02T14:00:36Z,2018-11-02T14:00:36Z,1995,Mechanical Engineering,doi:10.15781/T2T72817T,http://hdl.handle.net/2152/69328,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['SFF', 'CAD', 'STL']",The Use of STEP to Integrate Design and Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/070a7797-828f-44bb-ae6e-82656fe7d415/download,,"The Standard for the Exchange of Product Model Data (STEP), ISO 10303, is a developing
International Standard for the exchange of product information between many different engineering
and manufacturing applications. This paper describes an architecture and methodology, using
STEP, that integrates a heterogeneous environment of CAD and Solid Freeform Fabrication (SFF)
systems. The prototype software discussed in this paper demonstrates the use of STEP to provide
CAD product data to a SFF system. The architecture described in this paper also addresses the role
of the STEP standards in an environment where STL and other SFF part data formats must also be
supported.",,,,,,
"['Lough, Cody S.', 'Wang, Xin', 'Smith, Christopher C.', 'Adeniji, Olaseni', 'Landers, Robert G.', 'Bristow, Douglas A.', 'Kinzel, Edward C.']",2021-11-15T22:31:24Z,2021-11-15T22:31:24Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90296', 'http://dx.doi.org/10.26153/tsw/17217']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['SWIR imaging', 'monitoring', 'part quality', 'defect location', 'defects', '304L', 'stainless steel', 'selective laser melting']",Use of SWIR Imaging to Monitor Layer-to-Layer Part Quality During SLM of 304L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/2d8a149d-ee4f-4221-a91c-0c87a3424337/download,University of Texas at Austin,"This paper evaluates using in-situ SWIR imaging to monitor part quality and identify
potential defect locations introduced during Selective Laser Melting (SLM) of 304L stainless steel.
The microstructure (porosity, grain size, and phase field) and engineering properties (density,
modulus, and yield strength) depend on the thermal history during SLM manufacturing. Tensile
test specimens have been built with a Renishaw AM250 using varied processing conditions to
generate different thermal histories. SWIR imaging data is processed layer-to-layer to extract
features in the thermal history for each process condition. The features in the thermal history are
correlated with resulting part engineering properties, microstructure, and defects. The use of SWIR
imaging is then discussed as a potential for processes monitoring to ensure part quality and develop
layer-to-layer control in SLM.","This work was funded by Honeywell Federal Manufacturing &
Technologies under Contract No. DE-NA0002839 with the U.S. Department of Energy.",,,,,
"['Wang, Yanshuo', 'Dong, Jian', 'Marcus, Harris L.']",2018-12-07T16:23:37Z,2018-12-07T16:23:37Z,1997,Mechanical Engineering,doi:10.15781/T2VQ2SX0F,http://hdl.handle.net/2152/71447,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['SFF', '3D System']",The Use of VRML to Integrate Design and Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d3feeffb-ad35-4525-98d3-732779a3d319/download,,"The Virtual Reality Modeling Language (VRML) was created to put interconnected 3D
worlds onto every desktop. The 3D VRML format has the potential for 3D fax and TeleManufacture.
An architecture and methodology of using VRML format to integrate a 3D model
and Solid Freeform Fabrication system are described in this paper. The prototype software
discussed in this paper demonstrates the use of VRML for Solid Freeform Fabrication process
planning. The path used from design to part will be described.",,,,,,
"['de Jager, P.J.', 'Broek, J.J.', 'Vergeest, J.S.M.']",2018-12-06T22:25:40Z,2018-12-06T22:25:40Z,1997,Mechanical Engineering,doi:10.15781/T2571878Q,http://hdl.handle.net/2152/71437,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['zero order approximation', 'ruled slices']",Using adaptive ruled layers for Rapid Prototyping: principles and first results,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1ba753a4-7bf4-4217-ae5d-689c239914d0/download,,"Current 2.5D layered rapid prototyping has as disadvantage the staircase effect, requiring thin
layers to be used to achieve a reasonable accuracy. Slices with inclined outer surfaces can be
constructed using linear interpolation between adjacent contours, resulting in ruled slices. A
methodology to approximate a given model geometry within a specified accuracy using ruled
slices and an adaptive layer thickness is described. This involves matching successive contours
and analysing the geometry for curvature and inclination to calculate allowed layerthicknesses.
First results show a significant reduction in the number of layers when compared to adaptive
slicing using 2.5D layers. A proof-of-concept software, the Delft University of Technology
Improved Slicer (DUTIS) has been developed to perform the adaptive slicing using either 2.5D or
ruled layers allowing a comparison between the two alternative methods.",,,,,,
"['Roach, R.A.', 'Bishop, J.E.', 'Johnson, K.', 'Rodgers, T.', 'Boyce, B.L.', 'Swiler, L.', 'van Bloemen Waanders, B.', 'Chandross, M.', 'Kammler, D.', 'Balch, D.', 'Jared, B.', 'Martinez, M.J.', 'Leathe, N.', 'Ford, K.']",2021-11-08T23:25:59Z,2021-11-08T23:25:59Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90074', 'http://dx.doi.org/10.26153/tsw/16995']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['qualification paradigm', 'additive manufacturing', 'performance prediction', 'manufacturing control', 'cycles of learning']",Using Additive Manufacturing as a Pathway to Change the Qualification Paradigm,Conference paper,https://repositories.lib.utexas.edu//bitstreams/49b1be15-f305-4566-a461-1aebc2410aec/download,University of Texas at Austin,"Additive Manufacturing (AM) offers the opportunity to transform design, manufacturing,
and qualification with its unique capabilities. AM is a disruptive technology, allowing the
capability to simultaneously create part and material while tightly controlling and monitoring the
manufacturing process at the voxel level, with the inherent flexibility and agility in printing
layer-by-layer. AM enables the possibility of measuring critical material and part parameters
during manufacturing, thus changing the way we collect data, assess performance, and accept or
qualify parts. It provides an opportunity to shift from the current iterative design-build-test
qualification paradigm using traditional manufacturing processes to design-by-predictivity where
requirements are addressed concurrently and rapidly. The new qualification paradigm driven by
AM provides the opportunity to predict performance probabilistically, to optimally control the
manufacturing process, and to implement accelerated cycles of learning. Exploiting these
capabilities to realize a new uncertainty quantification-driven qualification that is rapid, flexible,
and practical is the focus of this paper.",,,,,,
"['Murphy, C.', 'Meisel, N.', 'Simpson, T.W.', 'McComb, C.']",2021-11-11T16:29:05Z,2021-11-11T16:29:05Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90237', 'http://dx.doi.org/10.26153/tsw/17158']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['part mass', 'support material', 'build time', 'automation', 'deep learning', 'voxel patterns', 'design for additive manufacturing', 'DfAM']","Using Autoencoded Voxel Patterns to Predict Part Mass, Required Support Material, and Build Time",Conference paper,https://repositories.lib.utexas.edu//bitstreams/1d954d13-2bce-4293-b26e-b1ed67735a24/download,University of Texas at Austin,"Additive Manufacturing (AM) allows designers to create intricate geometries that were
once too complex or expensive to achieve through traditional manufacturing processes. Currently,
designing parts using features specific to AM, commonly referred to as Design for Additive
Manufacturing (DfAM), is restricted to experts in the field. As a result novices in industry may
overlook potentially transformational design potential enabled by AM. This project aims to
automate DfAM through deep learning making it accessible to a broader audience, and enabling
designers of all skill levels to leverage unique AM geometries when creating new designs. To
execute such an approach, a database of files was acquired from industry-sponsored AM
challenges focused on lightweight design. These files were converted to a voxelized format, which
provides more robust information for machine learning applications. Next, an autoencoder was
constructed to a low-dimensional representation of the part designs. Finally, that autoencoder was
used to construct a deep neural network capable of predicting various DfAM attributes. This work
demonstrates a novel foray towards a more extensive DfAM support system that supports
designers at all experience levels.",,,,,,
"['Campbell, R.I.', 'de Beer, D.J.']",2021-09-23T22:32:47Z,2021-09-23T22:32:47Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88040', 'http://dx.doi.org/10.26153/tsw/14981']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping models', 'customer interaction with functional prototypes', 'solid freeform fabrication']",Using Customer Interaction with Functional Prototypes to Support Innovative Product Development,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dfeb7ae7-57f4-407d-8829-7045943da5f6/download,,"Rapid prototyping models have often been used to facilitate customer evaluation and approval of
design concepts. This paper presents a method known as customer interaction with functional
prototypes (CIFP) aimed at enabling customers to make a more creative input into the new
product development process. The basic premise is that the solid freeform fabrication (SFF)
technologies used for rapid manufacturing also enable more representative prototypes that can be
used for full and frequent customer interaction in the design process. This paper reports an
extended investigation where CIFP was used successfully within a small company to introduce a
new range of innovative motion analysis products.",,,,,,
"['Ma, Li', 'Fong, Jeffrey', 'Lane, Brandon', 'Moylan, Shawn', 'Filliben, James', 'Heckert, Alan', 'Levine, Lyle']",2021-10-19T18:49:07Z,2021-10-19T18:49:07Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89322,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'finite element analysis', 'design of experiments', 'simulation parameters']",Using Design of Experiments in Finite Element Modeling to Identify Critical Variables for Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac5b92ce-969b-41a1-b5c6-237041148bbe/download,University of Texas at Austin,"Input of accurate material and simulation parameters is critical for accurate predictions in
Laser Powder Bed Fusion (L-PBF) Finite Element Analysis (FEA). It is challenging and
resource consuming to run experiments that measure and control all possible material properties
and process parameters. In this research, we developed a 3-dimensional thermal L-PBF FEA
model for a single track laser scan on one layer of metal powder above a solid metal substrate.
We applied a design of experiments (DOE) approach which varies simulation parameters to
identify critical variables in L-PBF. DOE is an exploratory tool for examining a large number of
factors and alternative modeling approaches. It also determines which approaches can best
predict L-PBF process performance.",,,,,,
"['McKay, David S.', 'Davis, Hubert P.', 'Burns, Marshall']",2018-11-08T19:29:54Z,2018-11-08T19:29:54Z,1996,Mechanical Engineering,doi:10.15781/T2VX06P12,http://hdl.handle.net/2152/69914,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['additive fabricators', 'technology', 'suitable fab processes']",Using Fabricators to Reduce Space Transportation Costs,Conference paper,https://repositories.lib.utexas.edu//bitstreams/443acc33-1c4a-4ef8-8e33-42aac5c2c126/download,,"Ever since the Apollo landings, one ofthe primary barriers to more ambitious space projects has been the exorbitant
cost oflifting equipment and construction components off ofthe Earth. Fabricators offer an intriguing solution by
allowing for the use of native materials on the Moon, Mars, or other destinations in the production of tool and
building parts. This paper discusses
• The kinds ofobjects that can be practically made in this fashion,
• Fabricator processes suitable for extraterrestrial environments,
• Raw materials available, and
• The impact ofthis use oftechnology on the cost ofspace projects",,,,,,
"Stucker, Brent",2020-03-10T16:31:48Z,2020-03-10T16:31:48Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80226', 'http://dx.doi.org/10.26153/tsw/7245']",eng,2008 International Solid Freeform Fabrication Symposium,Open,solid freeform fabrication,Using Literature Reviews as a Learning Tool for Solid Freeform Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6fc8460-6846-4917-850e-51c0a8faf5fe/download,,"Over the past six years, students involved in the “Non-Traditional & Additive Manufacturing”
course at Utah State University have been assigned an in-depth literature review as one their
course projects. This literature review, done in groups of 2 or 3 students, involves becoming an
expert on a topic of interest to the students and then presenting this material to the class as an indepth, oral presentation in addition to writing a journal-like review article on the topic. This
project has proved to be a consistently effective method for enhancing learning of SFF
technologies and their applications, and has been consistently noted by students in their course
evaluations as a highly effective teaching tool. The methodology used for assigning and
assessing these projects will be explored, in addition to a discussion of the benefits of this project
toward meeting ABET criteria for accreditation of engineering programs.",,,,,,
"['Fisher, Joseph W.', 'Miller, Simon W.', 'Bartolai, Joseph', 'Yukish, Michael A.']",2023-03-01T17:25:13Z,2023-03-01T17:25:13Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117551', 'http://dx.doi.org/10.26153/tsw/44431']",eng,2022 International Solid Freeform Fabrication Symposium,Open,Lattice Structure,Using Mean Curvature of Implicitly Defined Minimal Surface Approximations to Generate New Unit Cells for Lattice Design,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ba44c249-babb-48e4-8213-5f2bb8e9aa98/download,,"Triply Periodic Minimal Surfaces (TPMS) are smoothly varying surfaces that exhibit zero
mean curvature at all points on the surface. TPMS can be modeled with high accuracy us-
ing discrete differential geometry techniques. However, generating a useful number of unit
cells with this approach would be computationally expensive, and variable lattices would
be impossible. Level sets of Fourier series approximations are often used instead. While
these approximations have continuous geometry, they no longer retain zero mean curvature
like the exact TPMS. In this paper, we calculate the mean curvature of the commonly used
approximations of the gyroid and D-surface TPMS. Using isosurfaces of the mean curvature
from these approximates, we define, similar but unique surface topologies. The development
of these surfaces expands the list of lattices available to designers, broadening the lattice design
space. Application to other approximations and further study of the application of these new
surfaces is discussed.",,,,,,
"['Williams, T.', 'Storti, D.', 'Ganter, M.']",2021-12-07T17:34:57Z,2021-12-07T17:34:57Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90732', 'http://dx.doi.org/10.26153/tsw/17651']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['infill structures', 'Voronoi cell', 'medial surfaces', '3D printing']",Using Medial Surfaces to Produce Graded Voronoi Cell Infill Structures for 3D Printed Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4fff7c6-fb17-4914-b51e-cec147447605/download,University of Texas at Austin,"Many methods of additive manufacturing rely on infill structures to decrease part mass
and print time. However, standard infill patterns generally use a uniform density or require
time-consuming analysis to generate a density field tailored to part geometry. We propose a
Voronoi cell based infill structure which uses the medial surfaces of the object to locate thin
regions and increase local material density. The Voronoi cell structure reduces transition points
within the infill, producing a more even gradient in density, while the weighting scheme ensures
that traditionally weaker portions of the model receive adequate internal support.",,,,,,
"['Penney, J.J.', 'Hamel, W.R.']",2021-11-30T19:20:22Z,2021-11-30T19:20:22Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90519', 'http://dx.doi.org/10.26153/tsw/17438']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['large-scale additive manufacturing', 'non-gravity aligned', 'weld pool', 'metal parts']",Using Non-Gravity Aligned Welding in Large Scale Additive Metals Manufacturing for Building Complex Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9e5e084f-f3a8-4bd2-a70d-addb9314cd5b/download,University of Texas at Austin,"One of the most difficult aspects of printing large, complex metal parts is building large
overhangs without the use of support structures. When using typical gas metal arc welding
techniques, the torch is kept aligned with the gravitational direction. It has been shown that the
maximum overhang angle that can be achieved is roughly 25°. This maximum can be increased
by using part positioner, but this adds extra system complexity, especially for creating the robot
paths. It is desirable then to develop a method of printing with the torch in a Non-Gravity Aligned
(NGA) direction, such that the weld pool is supported and will produce the desired weld bead.
This work focuses on the development of a control scheme based on sensor feedback of the state
of the weld pool to maintain a stable, desired weld pool shape and thus print more complex
parts using the gas metal arc welding process.",,,,,,
"['Williams, T.', 'Langehennig, S.', 'Ganter, M.', 'Storti, D.']",2021-11-30T19:30:46Z,2021-11-30T19:30:46Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90522', 'http://dx.doi.org/10.26153/tsw/17441']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'infill structures', 'support structures', 'Voronoi cells', 'algorithm']",Using Parallel Computing Techniques to Algorithmically Generate Voronoi Support and Infill Structures for 3D Printed Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4364fe80-082f-4f32-ab8b-89c70aefb3c6/download,University of Texas at Austin,"Many methods of 3D printing rely on support and infill structures in order to produce
quality parts. This paper formulates an algorithm that produces support and/or infill structures
based on Voronoi cells for objects described by a function or a closed triangulated mesh. The
algorithm utilizes Voronoi structures with a high degree of customization provided to the end
user, and takes advantage of parallel computing to cut down on the computation time required to
generate these structures. The aforementioned method is novel because it uses Voronoi
structures as supports and combines support and infill generation into a single process,
displaying the flexibility of Voronoi foam structures in 3D printing applications. The primary
focus is the implementation of the algorithm itself and the customization capabilities it provides.",,,,,,
"['Chesser, Phillip C.', 'Lind, Randall F.', 'Post, Brian K.', 'Roschli, Alex', 'Love, Lonnie J.', 'Gaul, Katherine T.']",2021-11-09T19:17:51Z,2021-11-09T19:17:51Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90139', 'http://dx.doi.org/10.26153/tsw/17060']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['post-tensioning', 'z-strength', 'load bearing structures', 'large scale additive manufacturing', 'big area additive manufacturing', 'BAAM']",Using Post-Tensioning in Large Scale Additive Parts for Load Bearing Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df48b008-29f9-4c58-a574-cb1446ee4a6a/download,University of Texas at Austin,"One of the perennial problems with additive manufacturing (AM) is the lack of inter-laminar bond
strength between the layers, also known as z-strength. This can make the use of AM fabricated
parts in load bearing applications problematic. This problem can be solved in some applications
with post-tensioning. The use of post-tensioning in structures can be used to ensure that layer
interfaces only see compressive stresses. This method is commonly used to strengthen concrete
structures since concrete is weak in tension while strong in compression. This paper explores the
successful application of post-tensioning to improve z-strength of large structures made with Big
Area Additive Manufacturing (BAAM) where loads are significant. Theory and examples are
presented herein.",,,,,,
"['Messing, Andrew', 'Roschli, Alex', 'Post, Brian K.', 'Love, Lonnie J.']",2021-11-02T20:12:03Z,2021-11-02T20:12:03Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89884,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['skeletons', 'void filling', 'overfilling', 'underfilling', 'large-scale additive manufacturing', 'skeletonization']",Using Skeletons for Void Filling in Large-Scale Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/66745bc5-1e9b-4d7b-854f-3fa145896fce/download,University of Texas at Austin,"In additive manufacturing (AM), slicing software is used to generate tool paths that are
then converted to G-Code, which tells the 3D printer how to build a part. Toolpaths are generated
using closed-loop paths. Sometimes the space left for a closed-loop is not sized perfectly. This can
lead to overfill or underfill issues. Therefore, skeletonization of a polygon seeks to resolve this
issue by creating an open-loop path to fill the voids between adjacent toolpaths. A straight skeleton
was used to explore this work. Straight skeletonization represents the topological skeleton of a
shape through line segments. After skeletonization, the extrusion rate can be varied to adjust bead
width more precisely to fill the gap.",,,,,,
"['Dwivedi, Rajeev', 'Shah, Parthiv', 'Bhupathiraju, Rohit', 'Dwivedi, Indira', 'Dwivedi, Bharat', 'Agarwal, Anvita', 'Rebbapragada, Arun Skanda', 'Agarwal, Ria', 'Singh, Nehal', 'Bhupathiraju, Ravi', 'Rebbapragada, Surya']",2023-01-26T21:47:28Z,2023-01-26T21:47:28Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117325', 'http://dx.doi.org/10.26153/tsw/44206']",eng,2022 International Solid Freeform Fabrication Symposium,Open,robotics,Using Solid Freeform Fabrication to develop a low-cost Robotics experiment platform to complement  classroom learning and exploring topics in STEM Education,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d076310d-892a-4f12-8c4f-d58ae7af785f/download,,"Educational and competitive robotics provide avenue for hands on experimentation and hence effective 
tools for STEM education. Cost of physical components continues to be a limiting factor. Within the Educational 
Robotics, the kits (LEGO, VEX, REV, etc.) are beyond the reach of most of the communities across the world. 
“Robotics for All” is an initiative to enable a versatile cost-effective platform to provide a minimum set of parts 
that students can integrate with general purpose as well as custom controller/microcomputers (Arduino, 
Raspberry-Pi, BBC microbit) to perform range of experiments. Various sensors and camera modules can be easily 
integrated to further learning and experimentation. It will be possible to perform experiments in Robot Navigation, 
Process planning, object manipulation, industrial architectures, Machine Learning etc. Solid Freeform Fabrication 
was used to enable manufacturing, verification and improve the design of piece parts with emphasis on low cost 
without compromise on learning opportunities.",,,,,,
"['Andrew, K.', 'Weaver, J.M.']",2021-11-30T20:59:13Z,2021-11-30T20:59:13Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90546', 'http://dx.doi.org/10.26153/tsw/17465']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['wax filament', 'castings', 'fused filament fabrication']",Using Wax Filament Additive Manufacturing for Low-Volume Investment Casting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eb66d4d1-ef76-48fc-b0ae-6d572d75bb99/download,University of Texas at Austin,"Investment casting is a popular method of converting wax or polymer patterns into metal
objects. For low-volumes these patterns can be manufactured using additive manufacturing.
However, burning out conventional additive thermoplastics like PLA can be more problematic
than removing wax. Often these plastics leave ash residue on the cavity surface, leading to
defects in the final metal part. Possible solutions to this problem include using ash-free materials
like wax or adjusting parameters to lessen ash buildup. With sufficient consistency in quality,
investment casting can be an attractive alternative to metal additive processes. This paper
discusses using wax filament on a conventional desktop fused filament fabrication (FFF) additive
machine, including discoveries, settings, and design guidelines leading to successful wax prints.
The resulting wax filament castings are compared to identical castings produced from colored
PLA, and advantages and disadvantages of using wax filament are discussed.",,,,,,
"['Almusaied, Zaid', 'Asiabanpour, Bahram']",2021-12-01T21:40:20Z,2021-12-01T21:40:20Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90622', 'http://dx.doi.org/10.26153/tsw/17541']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'atmospheric water generator', 'thermoacoustic refrigeration']",Utilizing Additive Manufacturing in Thermoacoustic Refrigeration-based Atmospheric Water Generation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bfaaed40-1e6c-408a-8362-614fb53cc040/download,University of Texas at Austin,"Atmospheric water generators are devices that generate water by condensation. The water vapor in the air
is cooled, by a refrigeration system, below the dew point and thus forces a phase transfer from gaseous to
liquid. Thermoacoustic refrigeration (TAR) was used as the refrigeration technology. The TAR is an
innovative clean technology that utilizes an acoustic wave passing through a gas to create a temperature
gradient in a specially designed porous material. The main components of such a system are resonator tube,
stack, acoustic driver, gas, and heat exchangers. An additive manufacturing process was utilized to develop
different configurations and interchangeable components of the TAR system. The lowest temperature on
the cold side of the stack was achieved by the stack manufactured with spiral design, spacing of 0.53 mm,
4cm length, and 1cm stack position in the resonator tube. The minimum temperature achieved with this
prototype was around 46 ̊F at a room temperature of 72 ̊F, relative humidity of 59%, and dew point of 57 ̊
F.",,,,,,
"['Smith, C.J.', 'Todd, I.', 'Gilbert, M.']",2021-10-12T18:09:38Z,2021-10-12T18:09:38Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88710', 'http://dx.doi.org/10.26153/tsw/15644']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['structural optimization', 'additive manufacturing', 'load testing', 'load carrying capacity', 'layout optimization', 'Ti-6Al-4V', 'titanium']",Utilizing Additive Manufacturing Techniques to Fabricate Weight Optimized Components Designed using Structural Optimization Methods,Conference paper,https://repositories.lib.utexas.edu//bitstreams/eaf8e8c8-f7d0-423e-b154-ea7afca4db0b/download,University of Texas at Austin,"This paper describes a preliminary study of the application of structural optimization
techniques to the design of additively manufactured components, using load testing to failure
to establish true load carrying capacity. The cantilever component specimens fabricated were
designed to resist a tip load and comprised one conventional benchmark design and two
designs developed using layout optimization (LO) techniques. The designs were fabricated
from Titanium Ti-6Al-4V and then scanned for internal defects using X-Ray Computed
Tomography (XCT). All three specimens failed below the design load during testing. Several
issues were identified in both the design optimization and fabrication phases of the work,
contributing to the premature failure of the specimens. Various recommendations to improve
the optimization phase are presented in the paper.",,,,,,
"['Alshaikh Ali, Mohammad', 'Fidan, Ismail', 'Allen, Michael', 'Bhattacharya, Indranil', 'Tantawi, Khalid']",2023-03-01T17:21:29Z,2023-03-01T17:21:29Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117550', 'http://dx.doi.org/10.26153/tsw/44430']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Stereolithography', 'Fused Filament Fabrication', 'Lattice Structure', 'Energy Consumption']",Utilizing Lattice Infill Structures to Optimize Weight with Structural Integrity Investigation for Commonly Used  3D Printing Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9c9a93b3-95b0-45c2-ac50-5ad41979bce3/download,,"Additive Manufacturing (AM) is utilized in various applications and fields. This research 
study investigates the use of lattice infill structures to reduce weight in two commonly used AM 
methods; Stereolithography (SLA) and Fused Filament Fabrication (FFF). Structural integrity of 
lattice infilled parts is investigated. Before utilizing lattice infill structures, different process 
parameters are also investigated to gain a knowledge base for these patterns’ effect on weight and 
power consumption (PC). Cubes are used as test specimens to perform the knowledge base study 
for the process parameters. Based on the initial study, an infill pattern is chosen to be compared 
with a lattice infill structure. The test specimens for this study are chosen to be of different 
background and complexity. Experimental data indicates a reduction in weight with no increase in 
PC for SLA and an increase in PC for FFF. Lattice infilled structures respond well to structural 
integrity testing.",,,,,,
"['Brackett, D.J.', 'Ashcroft, I.A.', 'Hague, R.J.']",2021-09-23T22:43:01Z,2021-09-23T22:43:01Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88043', 'http://dx.doi.org/10.26153/tsw/14984']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['brass musical instruments', 'Rapid Manufacturing', 'structural interactions', 'acoustical interactions']",Utilizing the Design Freedoms of Rapid Manufacturing to Optimise Structural and Acoustal Interactions of 'Brass' Musical Instruments,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd809bd5-a3da-4bf0-bc9b-dbebc838cff1/download,,"The feasibility of the production of end use ‘brass’ musical instruments using Rapid
Manufacturing (RM) is discussed with an emphasis on optimising the structural resonance
through stiffening structures. The method is based upon a coupling between the air-column and
structure when their resonant frequencies approach each other, which accentuates the players’ lip
to wall coupling effect. The degree of wall vibration and the frequencies at which it occurs can
be controlled by variation of the structure’s stiffness and the design freedoms allowed by RM
enable greater control of this. Initial results of the structures and their performance are presented.",,,,,,
"['Rock, Stephen J.', 'Wozny, Michael J.']",2018-04-12T18:14:16Z,2018-04-12T18:14:16Z,1991,Mechanical Engineering,doi:10.15781/T2FN1186X,http://hdl.handle.net/2152/64278,eng,1991 International Solid Freeform Fabrication Symposium,Open,"['Rensselaer Design Research Center', 'Rensselaer Polytechnic Institute', 'SFF', 'SLS']",Utilizing Topological Information to Increase Scan Vector Generation Efficiency,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a2840b89-2588-46e1-915d-fd4581fc8b27/download,,"Demands for increased Solid Freeform Fabrication precision and speed suggest the
need for advanced scanning techniques, such as boundary tracing, half-lap and multiple
orientation scanning, or 'intel nt' scanning. Since most SFF processes construct parts
from parallel material layers, separating model slicing and scan conversion functions
appears to be a powerful approach. Both can benefit from increased topological
information. This paper addresses the issue of improving model slicing by utilizing
topological data to increase performance, and consequently, improve the efficiency with
which scan vectors can be generated.",,,,,,
"['Starly, B.', 'Chang, R.', 'Sun, W.']",2020-02-27T20:22:08Z,2020-02-27T20:22:08Z,2006,Mechanical Engineering,,"['https://hdl.handle.net/2152/80100', 'http://dx.doi.org/10.26153/tsw/7121']",eng,2006 International Solid Freeform Fabrication Symposium,Open,poly-ethylene diacrylate,UV-Photolithography Fabrication of Poly-Ethylene Glycol Hydrogels Encapsulated with Hepatocytes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d2fdbd6b-7c80-4243-9153-3d78df881292/download,,"The development of biomanufacturing technologies particularly, layered manufacturing has
advanced cell encapsulation processes in an effort to mimic the cellular microenvironment for invitro studies. This paper illustrates an inexpensive UV-photolithographic method for
encapsulation of human hepatocytes in three dimensional structures using poly-ethylene
diacrylate (PEGDA) hydrogels as candidate substrates. In order to further develop this
technology for layered fabrication, we have quantified the long-term effects of the photo-initiator
concentration and UV light exposure on the metabolic rates of encapsulated human hepatocytes
under a 21 day study. The photoinitator toxicity was observed immediately after polymerization
with no significant cytotoxicity on a long term basis. A cellular viability is examined and
reported for the UV photopolymerization process. Cell phenotype maintenance was observed by
measuring the amount of urea produced over a 1 week time period. This photo encapsulation
process may find use in the fabrication of spatially complex 3D scaffolds for tissue engineering
applications, elucidation of the 3D structure-pharmacokinetic response relationship and the
fabrication of complex multi-compartment liver tissue analog devices for drug screening
applications.",,,,,,
"['Butcher, D.', 'Christie, S.', 'Brown, S.G.R.', 'Lavery, N.P.']",2021-11-18T17:15:53Z,2021-11-18T17:15:53Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90433', 'http://dx.doi.org/10.26153/tsw/17354']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['melt pool ejecta', 'mechanical properties', 'build failure', 'computational modelling technique', 'laser powder bed fusion']",Validated Computational Modelling Techniques for Simulating Melt Pool Ejecta In Laser Powder Bed Fusion Processing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/53db1677-0fd4-4151-b2f8-cd6e4b5d8338/download,University of Texas at Austin,"Industry currently require faster build rates from laser powder bed fusion processes. As
such, higher power lasers and multi-laser systems are being explored. Due to instabilities in the
melting process, material is ejected from the melt pool in the form of spatter and vapour. Previous
work has shown that these ‘ejecta’ can result in attenuation of the laser and redeposition of lager
particles onto the powder bed; which can lead to poor mechanical properties.
 ANSYS Fluent was used to create a CFD model which was validated against hot wire
anemometry results from Renishaw’s RenAM 500Q. This was then coupled with a Discrete Phase
Model (DPM) to track the ejection of spatter and vapour from the melt pool through the chamber.
This has led to a better understanding of the removal of ‘ejecta’, leading to increased mechanical
properties and lower rates of build failure.",,,,,,
"['Bhate, D.', 'Van Soest, J.', 'Reeher, J.', 'Patel, D.', 'Gibson, D.', 'Gerbasi, J.', 'Finfrock, M.']",2021-11-01T21:13:31Z,2021-11-01T21:13:31Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89755,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['elastic response', 'ULTEM-9085', 'honeycomb structures', 'methodology', 'fused deposition modeling']",A Validated Methodology for Predicting the Mechanical Behavior of Ultem-9085 Honeycomb Structures Manufactured by Fused Deposition Modeling,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a0ccfed-8a6d-4bef-8cf4-13da387a3bff/download,University of Texas at Austin,"ULTEM-9085 has established itself as the Additive Manufacturing (AM) polymer of choice
for end-use applications such as ducts, housings, brackets and shrouds. The design freedom
enabled by AM processes has allowed us to build structures with complex internal lattice structures
to enhance part performance. While solutions exist for designing and manufacturing cellular
structures, there are no reliable ways to predict their behavior that account for both the geometric
and process complexity of these structures. In this work, we first show how the use of published
values of elastic modulus for ULTEM-9085 honeycomb structures in FE simulation results in 40-
60% error in the predicted elastic response. We then develop a methodology that combines
experimental, analytical and numerical techniques to predict elastic response within a 5%
error. We believe our methodology is extendable to other processes, materials and geometries and
discuss future work in this regard.",,,,,,
"['Moritzer, E.', 'Hecker, F.']",2023-04-05T13:59:39Z,2023-04-05T13:59:39Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117778', 'http://dx.doi.org/10.26153/tsw/44657']",eng,2022 International Solid Freeform Fabrication Symposium,Open,FEM,Validation and Comparison of Fem-Simulation Results of the Fused Deposition Modeling Process under  Consideration of Different Mesh Resolutions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3f1547e-e8b2-4a16-b8aa-035ec4b83f7c/download,,"The Fused Deposition Modeling (FDM) process is an Additive Manufacturing (AM) 
technology. In the FDM process, components are generated by feeding a thermoplastic polymer 
filament into a heated nozzle and depositing the molten material layer-by-layer in a defined 
way onto the building platform or an already existing component structure. The strand-by-
strand deposition leads to a complex cooling situation which contributes to the non-uniform 
shrinkage of components in the FDM-process. Using an AM plug-in for the FEM-simulation 
software Abaqus, the thermal and mechanical aspects of a component can be simulated 
according to the temporal sequence of the manufacturing process. For this, the birth-death-
method is used in the simulations. During the investigations, the simulation results regarding 
geometrical deviations are compared to the actual deviation of the manufactured specimens. 
Furthermore, the influences of the mesh resolution on the simulation results and the required 
time for the simulations are considered.",,,,,,
"['Schley, C.', 'Smith, G.F.']",2018-12-07T16:09:50Z,2018-12-07T16:09:50Z,1997,Mechanical Engineering,doi:10.15781/T2CN6ZK4F,http://hdl.handle.net/2152/71443,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['FEA', 'rapid prototyping']",Validation of Rapid Prototyping Material for Rapid Experimental Stress Analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bfa3627d-056c-49f3-b0e6-488b5c7384c2/download,,"The paper will detail the validation work carried out on various Rapid Prototyping (RP) materials to
determine their suitability for the application of Thermoelastic Stress Analysis. The overall objective
is to drastically reduce the product design cycle, by providing ""real experimental data"" for
correlation with Finite Element Analysis (FEA), prior to any expensive manufacturing process. In
order to achieve this the homogeneity of the Rapid Prototyping material has to be established to
ensure a valid transfer of results from model to actual part.",,,,,,
"['Cooke, A.L.', 'Soons, J.A.']",2021-09-29T22:20:23Z,2021-09-29T22:20:23Z,2010,Mechanical Engineering,,"['https://hdl.handle.net/2152/88219', 'http://dx.doi.org/10.26153/tsw/15160']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['geometric accuracy', 'variability', 'metal test part', 'electron beam', 'laser beam', 'powder bed', 'thermal fusion process', 'additive manufacturing']",Variability in the Geometric Accuracy of Additively Manufactured Test Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/24f35ec3-3fc8-4f8d-af01-5bce5a617d49/download,University of Texas at Austin,"This paper describes the results of a study on the variability in the geometric accuracy of a metal
test part manufactured by several service providers using either an electron beam or laser beam
powder bed thermal fusion process. The part was a circle-diamond-square test part with an
inverted cone that is used to evaluate the performance of five-axis milling machines. The study
was conducted to aid development of standardized parameters and test methods to specify and
evaluate the performance of additive manufacturing systems. Without standards for performance
characterization, it is difficult to match system capabilities with part requirements and ensure
consistent and predictable part quality across systems, operators, and manufacturing facilities.",,,,,,
"['Faes, M.', 'Wang, Y.', 'Lava, P.', 'Moens, D.']",2021-10-20T22:57:22Z,2021-10-20T22:57:22Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89383,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['laser sintering', 'PA-12', 'mechanical variability', 'non-deterministic']",Variability in the Mechanical Properties of Laser Sintered PA-12 Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b03021d3-f8a4-4868-b64c-324c83e9294c/download,University of Texas at Austin,"The quasi-static mechanical properties of Laser Sintered (LS) PA-12 material are highly influenced by the
thermal history of the thermoplastic material during the production, as this impacts critical material properties
such as the degree of crystallinity and porosity in the resulting component. Many process-related parameters,
including preheating temperature, laser energy density, layer interaction time and post-build cooling cycle, were
already shown to influence the thermal history significantly. Due to the large, mainly epistemic, variability in
these parameters, the mechanical response of produced components is often difficult to predict and is moreover
governed by non-isotropic constitutive equations. This work therefore focusses on the identification of this
variability in the mechanical behavior and the validation of experimentally obtained non-deterministic material
models. A non-deterministic (variable) constitutive model is built experimentally, based on 90 uniaxial tensile
tests, performed on LS samples that were built under different orientations. This model is subsequently validated
by building a well-defined benchmark sample, containing complex stress states upon loading. This sample is
tested using Digital Image Correlation. Finally, a novel way of identifying non-isotropic material properties, the
Virtual Fields Method, is applied to this benchmark sample to identify the constitutive parameters.",,,,,,
"['Habbal, Osama', 'Ayoub, Georges', 'Pannier, Christopher']",2021-12-07T18:15:39Z,2021-12-07T18:15:39Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90745', 'http://dx.doi.org/10.26153/tsw/17664']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['variable extrusion width', 'bead ith', 'bead trajectory', 'in-plane strength', 'fused filament fabrication', 'additive manufacturing']",Variable Extrusion Width for Interlocking Features in Fused Filament Fabrication 3D Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e8c67a6f-f4f2-43f1-9b81-6b3de8a9b4e3/download,University of Texas at Austin,"Following from developments in continuously variable extrusion width in fused filament
fabrication additive manufacturing, this work explores the combination of in-plane bead width variation
with bead trajectory variation as a technique to improve in-plane strength in polymer material extrusion
additive manufacturing. Sinusoidal in-plane waveforms are used for the extruder trajectory instead of
maintaining a straight line. The varied bead width, in conjunction with the non-straight bead trajectory,
reduces anisotropy of strength within the layer. The findings apply to fully dense infill of single layers,
commonly called horizontal perimeters in common slicing/toolpath planning computer programs.
Experimental tensile testing results show a 48.6% reduction in anisotropy of tensile strength driven by
43% and 29% increases in the ultimate tensile strength in the 0° and 45° orientations, respectively.
However, this comes at the cost of 99.6% reduction in toughness in the 90° orientation. We also present
the principal concept behind the machine code generating script, that allows for the increase and decrease
of the extruded bead width continuously along the extruded bead.",,,,,,
"['Wang, Huijun', 'Kovacevic, Radovan']",2019-09-23T16:38:29Z,2019-09-23T16:38:29Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75961', 'http://dx.doi.org/10.26153/tsw/3060']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Variable Polarity GTAW in Rapid Prototyping of Aluminum Parts 369,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e3269e05-3388-484c-a408-2f090de60ad5/download,,"This paper reports on a process to build aluminum alloy parts by variable polarity gas tungsten arc welding (GTAW). The relationship between the geometric sizes of the deposited layer and the welding parameters is investigated. A machine vision sensor is used to monitor and control the arc length that is a key welding parameter in the achievement of uniform deposition. By optimizing the depositing speed and the depositing layer thickness, there is no need for a cooling system to cool the part. Three Dimensional parts with different wall widths and different shapes are successfully obtained. The surfaces of the deposited aluminum parts are smooth and uniform.",,,,,,
"['Tang, Lie', 'Ruan, Jianzhong', 'Landers, Robert G.', 'Liou, Frank']",2020-03-09T13:19:56Z,2020-03-09T13:19:56Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80172', 'http://dx.doi.org/10.26153/tsw/7191']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Variable Powder Flow Rate Control,Variable Powder Flow Rate Control in Laser Metal Deposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/67a7a7c8-7927-47dd-9cf3-b35b197ac980/download,,"This paper proposes a novel technique, called Variable Powder Flow Rate Control (VPFRC), for
the regulation of powder flow rate in laser metal deposition processes. The idea of VPFRC is to
adjust the powder flow rate to maintain a uniform powder deposition per unit length even when
disturbances occur (e.g., the motion system accelerates and decelerates). Dynamic models of the
powder delivery system motor and the powder transport system (i.e., five–meter pipe, powder
dispenser, and cladding head) are first constructed. A general tracking controller is then designed
to track variable powder flow rate references. Since the powder flow rate at the nozzle exit
cannot be directly measured, it is estimated using the powder transport system model. The input
to this model is the DC motor rotation speed, which is estimated on–line using a Kalman filter.
Experiments are conducted to examine the performance of the proposed control methodology.
The experimental results demonstrate that VPFRC is successful in maintaining a uniform track
morphology, even when the motion control system accelerates and decelerates.",,,,,,
"['Chamberlain, Peter B.', 'Roosendaal, Mark D. Van', 'Thomas, Charles L.']",2019-02-22T17:47:52Z,2019-02-22T17:47:52Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73464', 'http://dx.doi.org/10.26153/tsw/614']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', '(zero order)']",Variable Thickness Ruled Edge Slice Generation and Three-Dimensional Graphical Error Visualization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/bd305342-f346-4d9b-9216-844582d05473/download,,"This paper describes a simple variable thickness ruled edged slicing algorithm that
produces slices with zero integrated error. In its present state, the algorithm requires presampled data to be taken from the STL file. Data points are extracted in a cylindrical
coordinate system giving values ofradius at regular intervals AS and Az. Using this data,
the algorithm creates slices based on averaging ofthe data points and the slope ofline
segments connecting them. Error based constraints are used to determine slice thickness.
A three-dimensional visualization technique using color contour plots (representing error)
on the surface ofthe prototyped model provides a means of evaluating the accuracy of
the prototyped part.",,,,,,
"['Whetten, S.R.', 'Lavin, J.M.', 'Keicher, D.M.', 'Appelhans, L.N.', 'Essien, M.', 'Mani, S.S.', 'Moore, P.B.', 'Cook, A.', 'Acree, N.A.', 'Young, N.P.', 'Russell, M.J.']",2021-10-28T20:29:05Z,2021-10-28T20:29:05Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89692,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['process variables', 'feature definition', 'polyimide films', 'film production', 'syringe deposition printing', 'direct write printing']",Variables Impacting Feature Definition of Polyimide Using Syringe Based Printing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4811f33-ee39-428f-a314-92b5051bf211/download,University of Texas at Austin,"Direct write printing approaches provide an opportunity for additive manufacturing (AM)
to impact the electronics industry through cost effective prototyping and manufacturing. Direct
write printing of electronics also provides the opportunity for the electronics industry to be
impacted by such things as new material research, fewer steps in processing, along with
application specific packaging and component configuration. This paper illustrates how process
variables affect the feature definition of polyimide film production via syringe deposition
printing. This work compares the films as the process variables change, and describes which
variables make the greatest impact on feature definition.",,,,,,
"['Heigel, J.C.', 'Lane, B.M.', 'Moylan, S.P.']",2021-10-28T21:32:08Z,2021-10-28T21:32:08Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89703,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['emmittivity', 'infrared camera', 'powder bed fusion', 'build parameters']",Variation of Emittivity with Powder Bed Fusion Build Parameters,Conference paper,https://repositories.lib.utexas.edu//bitstreams/037307b8-2042-44b2-9e83-16ae458f48e2/download,University of Texas at Austin,"Common approaches to process monitoring of powder bed fusion rely heavily on optical
measurements. These measurements can be used to verify powder spreading, assess the quality of
each layer, and measure process temperatures. In regards to the latter, radiometric detectors such
as cameras or pyrometers only measure radiant emissions from the surface, and do not directly
measure its temperature. Calculating the temperature from these measurements relies on the
calibration of the camera or pyrometer with a blackbody and on knowledge of the emittivity of the
surface being measured. Emittivity depends on multiple factors including surface texture and
viewing angle, among others. An apparatus and method for measuring emittivity using an infrared
camera is detailed. Measured emittivity values from metal surfaces produced using a commercial
powder bed fusion process are presented and related to temperature, viewing angle, and oxidation
state.",,,,,,
"['Xu, Changxue', 'Huang, Yong', 'Markwald, Roger R.']",2021-10-05T19:13:14Z,2021-10-05T19:13:14Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88413', 'http://dx.doi.org/10.26153/tsw/15352']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['organ printing', 'tissue engineering', 'vascular constructs', 'vertical 3D printing', 'horizontal 3D printing']",Vertical and Horizontal Fabrication of Alginate-Based Vascular-Like Constructs Using Inkjetting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/561224e4-f4f2-469f-9d77-d9e4eba0530e/download,University of Texas at Austin,"Organ printing, among different tissue engineering innovations, is a layer-by-layer
additive fabrication approach for making three-dimensional (3D) tissue and organ constructs
using cellular spheroids or bioink as building blocks. The capability to fabricate 3D cellular
tubes is the first step as well as an important indicator of the overall feasibility of envisioned
organ printing technology. In this study, vascular-like alginate tubes with a hemi-branching point,
which mimic typical vascular constructs, are fabricated both vertically and horizontally using
drop-on-demand inkjetting. In addition, manufacturing challenges associated with the vertical
and horizontal printing configurations are briefly discussed. This study lays a foundation for the
effective and efficient fabrication of viable 3D vascular constructs with complex anatomies (e.g.
branching) as required in organ printing of vascular trees.",,,,,,
"['Frye, Palmer', 'Muhammad, Muztahid', 'Simsiriwong, Jutima', 'Shamsaei, Nima']",2021-11-18T00:40:51Z,2021-11-18T00:40:51Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90375', 'http://dx.doi.org/10.26153/tsw/17296']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['very high cycle fatigue', 'VHCF', 'Inconel 718', 'laser beam powder bed fusion', 'LB-PBF']",Very High Cycle Fatigue Behavior of Laser Beam-Powder Bed Fused Inconel 718,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ace5a1f3-7b9e-45ca-80ad-eabcb3e0fbc2/download,University of Texas at Austin,"In this study, the very high cycle fatigue (VHCF) behavior of Inconel 718 manufactured
via a Laser Beam-Powder Bed Fusion (LB-PBF) process is investigated. LB-PBF Inconel 718
specimens are fabricated in vertical direction and subjected to post-processing heat treatment. The
experiment is conducted on as built (i.e. non-machined) specimens utilizing an ultrasonic fatigue
test system operating at 20 kHz under force-controlled fully-reversed constant amplitude cyclic
loading. Fractography analysis is performed using a digital microscope to identify microstructural
features that initiate fatigue cracks in the specimens. Experimental results from LB-PBF Inconel
718 specimens are presented and compared to those of wrought Inconel 718. It is determined that
the fatigue resistance of as-built LB-PBF Inconel 718 specimens is significantly less than that of
the wrought material. This result is attributed to a large presence of LB-PBF process intrinsic
defects. In the VHCF regime, subsurface crack initiation is the primary fatigue failure mechanism
in as-built LB-PBF Inconel 718 specimens.","In this study, the very high cycle fatigue (VHCF) behavior of Inconel 718 manufactured
via a Laser Beam-Powder Bed Fusion (LB-PBF) process is investigated. LB-PBF Inconel 718
specimens are fabricated in vertical direction and subjected to post-processing heat treatment. The
experiment is conducted on as built (i.e. non-machined) specimens utilizing an ultrasonic fatigue
test system operating at 20 kHz under force-controlled fully-reversed constant amplitude cyclic
loading. Fractography analysis is performed using a digital microscope to identify microstructural
features that initiate fatigue cracks in the specimens. Experimental results from LB-PBF Inconel
718 specimens are presented and compared to those of wrought Inconel 718. It is determined that
the fatigue resistance of as-built LB-PBF Inconel 718 specimens is significantly less than that of
the wrought material. This result is attributed to a large presence of LB-PBF process intrinsic
defects. In the VHCF regime, subsurface crack initiation is the primary fatigue failure mechanism
in as-built LB-PBF Inconel 718 specimens.",,,,,
"['Cohen, A.', 'Chen, R.', 'Frodis, U.', 'Wu, M.', 'Folk, C.']",2021-09-29T17:30:57Z,2021-09-29T17:30:57Z,2009-09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88196', 'http://dx.doi.org/10.26153/tsw/15137']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['metal micro-mechanisms', 'minimally-invasive medical devices', 'EFAB process']","Wafer-Scale, Solid Freeform Fabrication of Fully-Assembled Metal Micro-Mechanisms for Minimally-Invasive Medical Devices",Conference paper,https://repositories.lib.utexas.edu//bitstreams/1e4e37c1-3fae-4bd1-b69e-0d8a2eb9e5af/download,University of Texas at Austin,"The EFAB process was first presented at the SFF Symposium in 1998, at a very early
stage of its development. Currently, the technology is able to produce complex 3-D devices—
including mechanisms built pre-assembled—in production volumes, using a three-step process of
selective electrodeposition of one metal, blanket electrodeposition of another metal, and
planarization. Layer thickness is as small as 4 µm, minimum feature size is down to 10 µm, and
linear tolerances are ~2 µm. Metals are biocompatible materials with mechanical properties
similar to stainless steel. The technology enables new instruments for minimally-invasive
surgical and interventional procedures.",,,,,,
"['Arthur, Alan', 'Dickens, Phill', 'Bocking, Chris', 'Cobb, Richard']",2018-11-09T16:42:44Z,2018-11-09T16:42:44Z,1996,Mechanical Engineering,doi:10.15781/T2DR2PV2K,http://hdl.handle.net/2152/69935,eng,1996 International Solid Freeform Fabrication Symposium,Open,"['SL', 'RP', 'EDM']",Wear & Failure Mechanisms for SL EDM Electrodes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fee0dcd9-545e-4728-9266-7fb345b23377/download,,"The principle of Electro-Discharge Machining (EDM) electrode manufacture using rapid
prototyped Stereo Lithography (SL) models has been proposed and discussed in previous
published material by the authors [1,2,3,4]. Applying a thin electrodeposited coating of copper
to SL models has provided a direct route from model to tool cavity. A number of current factors
present limitations to the application of these electrodes. This paper outlines and addresses the
factors affecting electrode quality and performance. Premature failure of SL electrodes is
attributed to a number of wear and failure mechanisms which are being investigated at The
University of Nottingham. An overview of experimental and theoretical work is presented.",,,,,,
"['Kumar, S.', 'Kruth, J.-P.', 'Froyen, L.']",2021-09-23T22:35:20Z,2021-09-23T22:35:20Z,9/10/08,Mechanical Engineering,,"['https://hdl.handle.net/2152/88041', 'http://dx.doi.org/10.26153/tsw/14982']",eng,2008 International Solid Freeform Fabrication Symposium,Open,"['Selective Laser Sintering', 'SLS', 'WC-Co-Cu', 'fretting wear']",Wear Behaviour of SLS WC-Co Composites,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4b147645-f8c1-43c7-a3b9-89c599dcc46e/download,,,,text,,,,
"Kumar, S.",2020-03-10T17:44:02Z,2020-03-10T17:44:02Z,2008,Mechanical Engineering,,"['https://hdl.handle.net/2152/80240', 'http://dx.doi.org/10.26153/tsw/7259']",eng,2008 International Solid Freeform Fabrication Symposium,Open,Selective Laser Sintering,Wear of SLS Materials under Plastic and Elastic Contact Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/fc6f8017-a963-4a41-a007-411c7ea85521/download,,"Sliding wear behaviour of two SLS materials: LaserForm and DirectSteel has been
investigated using Fretting tests, Pin-on-disc tests and microfretting tests. Wear
test conditions were determined by calculating Hertzian pressure for various loading
conditions, and wear tests were performed under both plastic and elastic contact
conditions. Wear analysis was subsequently done to find out the wear resistance
of materials. The wear volumes are presented against applied loads and dissipated
energies. It has been found out that LaserForm is better than DirectSteel and there
is no clear relation between hardness and wear resistance of materials.",,,,,,
"['Ingenthron, C.', 'Ludwig, H.', 'Joel, T.', 'Agarwal, K.', 'Sealy, W.']",2021-10-20T22:06:05Z,2021-10-20T22:06:05Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89374,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'binder jetting', 'wear behavior', 'stainless steel-bronze', 'metal composites']",Wear Studies in Binder Jet Additive Manufactured Stainless Steel-Bronze Composite,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c692a71e-52c1-40ed-81b7-249593467e22/download,University of Texas at Austin,"Additive Manufactured (AM) components can be used for form, fit or function. If these
components have to replace the traditionally manufactured parts, they must be evaluated for their
properties. One of the properties that are very important in many cases is the wear of material in
service. The aim of this research is to study the wear behavior of additive manufactured
components under dry sliding conditions.
Small cylindrical disks of stainless steel 420-bronze composite were made by binder jet
AM process with layer thicknesses of 50 µm, 100 µm and 200 µm. These disks were subjected
to varying wear rates using pin-on-disk test based on ASTM standards. Different sliding
distances were used on samples to understand the wear phenomenon. The weight of samples
before and after tests was recorded to calculate wear rates. Wear debris and samples after testing
were evaluated under a scanning electron microscope (SEM) to reveal changes in microstructure.
Testing results are presented in this paper along with a discussion on how the wear occurs in the
SS420-Bronze composite. This information can be used for designing the products from this AM
process to match the requirements in service.",,,,,,
"['Schmithüsen, T.', 'Scleifenbaum, Johannes Henrich']",2021-11-30T20:43:08Z,2021-11-30T20:43:08Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90540', 'http://dx.doi.org/10.26153/tsw/17459']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['support removal', 'wet-chemical ablation', 'metal parts', 'laser powder bed fusion']",Wet-Chemical Support Removal for Additive Manufactured Metal Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3bab729d-7d06-4f27-b01c-5b5fb4a7bbc0/download,University of Texas at Austin,"The additive manufacturing technology laser powder bed fusion (LPBF) offers great flexibility regarding
the manufacturing of complex component structures. Due to the process, support structures have to
be manufactured for overhanging component surfaces in order to guarantee dimensional accuracy and
reduce distortion.
However, these must be removed after manufacturing. Especially for internally supported component surfaces,
removal is only possible by means of tool-free technologies. A promising approach for a tool-free support removal
is the wet-chemical ablation, in which the support structures are removed by chemical dissolution. So far, the
approach has been tested for a few materials (e.g. stainless steel). In order to extend the use of this automatable
approach to further AM materials, the influence of different etching agents on different additive aluminium
alloys with regard to material ablation and surface influence will be investigated. Finally, the applicability of the
results to a supported component will be tested.",,,,,,
"['Weflen, E.D.', 'Frank, M.C.', 'Peters, F.E.']",2024-03-26T23:30:34Z,2024-03-26T23:30:34Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124453', 'https://doi.org/10.26153/tsw/51061']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['metalcasting', 'WAAM', 'wire arc DED', 'human factors']",WIRE ARC ADDITIVE MANUFACTURING IN STEEL FOUNDRIES,Conference paper,https://repositories.lib.utexas.edu//bitstreams/80e5dec7-8a5c-4d5d-a860-a1e7b0d40bf2/download,University of Texas at Austin,"This work presents the system design of a robotic hybrid additive and subtractive
manufacturing system for steel foundries to reduce supply chain disruptions caused by a skilled
labor shortage and harsh working conditions. Automation promises to ease the labor shortage but
falls short in environments with high variation and ambiguous decision-making. These challenges
were overcome by leveraging human adaptability and uncertainty in decision-making, paired with
automation conducting repetitive tasks in harsh environments. Documenting the existing process
revealed the current welding approach for removing and refilling metalcasting production
anomalies. Tasks were divided into those suited for automation and those best suited for a human
operator. The operator continues to identify and remove anomalies while sensing and robotics
automate weld preparation by machining, refilling using Wire Arc Additive Manufacturing
(WAAM), and surface blending by grinding. This research serves as a case study for integrating
hybrid manufacturing into production environments.",,,,,,
"['Weflen, E.D.', 'Black, M.A.', 'Frank, M.C.', 'Peters, F.E.']",2021-12-01T21:52:28Z,2021-12-01T21:52:28Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90627', 'http://dx.doi.org/10.26153/tsw/17546']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['wire arc additive manufacturing', 'WAAM', 'low carbon steel', 'casting']",Wire Arc Additive Manufacturing of Low Carbon Steel for Casting Applications,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d5a5f91b-984a-44a5-9647-c20f427008d9/download,University of Texas at Austin,"While metal AM research often focuses on high-cost materials, lower-cost alloys such as
low carbon steel are used at higher volumes in the casting industry. Welding is a standard process
step in casting production, but robotic automation has been limited due to this industry’s low-volume and high-mix. However, advances in flexible automation show their potential. This
research presents the application of WAAM using a 6-axis robot with low carbon steel castings.
Process parameters, including travel speed, cooling time, and step over distance are evaluated for
their effect on the resulting geometry. Demonstration parts assess the ability to produce objects
with varying geometries without defects. A method is discussed for depositing material on non-planar surfaces, such as the filling of a concave feature. These findings broaden the scope of
applications in which wire arc additive manufacturing can be applied in industrial applications and
develops parameters for depositing within non-planar cavities.",,,,,,
"['Atkins, Celeste', 'Heineman, Jesse', 'Chesser, Phillip', 'Roschli, Alex', 'Post, Brian', 'Lloyd, Peter', 'Love, Lonnie', 'Lind, Randall']",2021-11-18T18:30:29Z,2021-11-18T18:30:29Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90458', 'http://dx.doi.org/10.26153/tsw/17379']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['wire co-extrusion', 'big area additive manufacturing', 'BAAM', 'Oak Ridge National Laboratory']",Wire Co-Extrusion with Big Area Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1c6792a1-d028-49f0-b2fe-19b991ca78cb/download,University of Texas at Austin,"Oak Ridge National Laboratory’s Manufacturing Demonstration Facility is developing a
system that will deposit and embed conductive and resistive elements within a printed bead of
material. The system was implemented on a Big Area Additive Manufacturing (BAAM) system
using a co-extruding nozzle. It has already been demonstrated that BAAM is useful for the tooling
industry, but this could be a great improvement on an established application of BAAM parts. This
system will provide the ability to control and monitor the surface of additively manufactured (AM)
parts. It will also enable self-heating surfaces of AM parts, which is particularly useful in tooling
applications. This system could even be used in the future for embedding other materials not found
in pellet form in BAAM parts. This work will cover the development of the co-extrusion system
and its integration with the dual-port nozzle and the BAAM system.",,,,,,
"['Gu, Jianglong', 'Cong, Baoqiang', 'Ding, Jialuo', 'Williams, Stewart W.', 'Zhai, Yuchun']",2021-10-12T22:56:41Z,2021-10-12T22:56:41Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88764', 'http://dx.doi.org/10.26153/tsw/15698']",,2014 International Solid Freeform Fabrication Symposium,Open,"['Wire+Arc Additive Manufacturing (WAAM)', 'Cold Metal Transfer (CMT)', 'aluminum', 'porosity', 'microstructure', 'mechanical property']",Wire+Arc Additive Manufacturing of Aluminum,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d86ed1d8-41ed-49d1-aafa-a20e4f114e59/download,University of Texas at Austin,"Wire+Arc Additive Manufacturing is very suitable for the production of large scale
aluminium parts. However implementation is currently limited by issues such as porosity and low
mechanical properties. We have studied the utilization of new deposition processes such as pulsed
advanced cold metal transfer which allows modification of the thermal profile resulting in refined
equiaxed microstructure and elimination of porosity. Standard and new feedstock compositions
are being evaluated and developed with ultimate tensile strengths of up to 260 MPa with 17%
elongation being obtained in the as-deposited condition. Post build heat treatments compositional
changes and high-pressure inter-pass rolling are being investigated in order to increase the
strength further.",,,,,,
"['Reichenbach, Alexandar', 'Silwal, Bishal']",2023-01-27T17:52:43Z,2023-01-27T17:52:43Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117348', 'http://dx.doi.org/10.26153/tsw/44229']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'wire-fed AM', 'RAFM steel']",Wire-Arc Additive Manufacturing of Reduced Activation Ferritic Martensitic (RAFM) Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d41d1e7-5337-4fdb-8bdb-1741047ec06a/download,,"RAFM steel has been considered as the candidate material for an in-vessel component of the fusion wall 
reactor. Known as F82H in Japan and Eurofer-97 in Europe, RAFM steel is not commercially available. 
The goal of this research project is to fabricate and study the technical feasibility of producing RAFM 
steel welding wire with wire arc AM. Metal-cored wire is a tubular electrode comprised of an outer 
metal sheath with alloying powdered materials inside the core. Applications of such wire include but not 
limited to welding, thermal spray, cladding and additive manufacturing (AM). The advantage of using the 
metal-cored wire is that a higher deposition rate, higher side-wall fusion, can be achieved, and more 
important, special alloys for special applications can be manufactured at relatively lower cost. A 
preliminary investigation of wire arc AM of RAFM steel was carried out using Ar-CO2 (c-25) gas. A design 
of experiments with GMAW based power source waveform using the metal cored wire was conducted 
to study the printability. The microstructure and mechanical properties (hardness and toughness) was 
tested, and the data were analyzed and compared with the literature.",,,,,,
"['Fowler, J.', 'Nycz, A.', 'Noakes, M.', 'Masuo, C.', 'Vaughan, D.']",2021-11-18T00:49:49Z,2021-11-18T00:49:49Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90378', 'http://dx.doi.org/10.26153/tsw/17299']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['Invar', 'wire-arc additive manufacturing', 'metal big area additive manufacturing', 'MBAAM', 'Oak Ridge National Laboratory']",Wire-Arc Additive Manufacturing: Invar Deposition Characterization,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0d3320e9-0fd1-4690-99e3-7699a231b434/download,University of Texas at Austin,"This paper explains and analyzes an investigation into the characteristics of Invar, a Nickel-Iron
alloy, with regards to deposition through Wire-Arc Additive Manufacturing performed by the Metal Big
Area Additive Manufacturing (MBAAM) team at Oak Ridge National Laboratory’s Manufacturing
Demonstration Facility (MDF). The Invar alloy is extremely valuable to multiple fields because of its
thermal expansion properties. These fields will attain financial benefits when turning to additive
manufacturing as the future production technique for their Invar parts. As such, it will be necessary for
AM research to become accustomed with the characteristics of Invar deposition. One of the potential
AM techniques that has the potential to carry out printing with this material is Wire-Arc AM. The goal
of this paper is to narrow down and call out different welding parameters that optimize the
characteristics of Invar deposition using the Wire-Arc AM technique.","This paper explains and analyzes an investigation into the characteristics of Invar, a Nickel-Iron
alloy, with regards to deposition through Wire-Arc Additive Manufacturing performed by the Metal Big
Area Additive Manufacturing (MBAAM) team at Oak Ridge National Laboratory’s Manufacturing
Demonstration Facility (MDF). The Invar alloy is extremely valuable to multiple fields because of its
thermal expansion properties. These fields will attain financial benefits when turning to additive
manufacturing as the future production technique for their Invar parts. As such, it will be necessary for
AM research to become accustomed with the characteristics of Invar deposition. One of the potential
AM techniques that has the potential to carry out printing with this material is Wire-Arc AM. The goal
of this paper is to narrow down and call out different welding parameters that optimize the
characteristics of Invar deposition using the Wire-Arc AM technique.",,,,,
"['Padathu, Ajay Panackal', 'Sparks, Todd', 'Liou, Frank']",2020-02-24T15:06:33Z,2020-02-24T15:06:33Z,2005,Mechanical Engineering,,"['https://hdl.handle.net/2152/80078', 'http://dx.doi.org/10.26153/tsw/7099']",eng,2005 International Solid Freeform Fabrication Symposium,Open,Laser Aided Manufacturing Process,Workpiece Alignment for Hybrid Laser Aided Part Repair Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df34f4bd-3111-4168-88d2-f6653d8ec685/download,,"Work piece alignment is a key issue for hybrid laser aided part repair, a process utilizing
both machining and laser deposition. Proper alignment can greatly improve the accuracy of the
repair process. This paper introduces a method for aligning a physical work piece and a CAD
model using a Renishaw touch probe and software tools. Also discussed is a model for
computing 5-axis CNC positions based on a desired work piece orientation.",,,,,,
"Austin F., Aubin",2018-09-27T19:44:33Z,2018-09-27T19:44:33Z,1994,Mechanical Engineering,doi:10.15781/T2G737P38,http://hdl.handle.net/2152/68607,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['intelligent manufacturing systems', 'Rapid product development', '3D Printing']",A World Wide Assessment of Rapid Prototyping Technologies,Conference paper,https://repositories.lib.utexas.edu//bitstreams/13471ba2-c96e-4886-896c-94a8ca6e18c0/download,,,,"This paper describes the results of a worldwide assessment of comnlercial rapid prototyping
technologies that was initiated in the Intelligent Manufacturing Systems IMS Test Case on Rapid
Product Development. Additionally, this paper will highlight the development of university-led
rapid prototyping technologies.",,,,
"['Sellers, R.', 'McCullough, C.', 'Gonzalez, E.', 'Light, A.', 'Wolff, S.', 'Wang, H.']",2023-04-05T13:55:15Z,2023-04-05T13:55:15Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117776', 'http://dx.doi.org/10.26153/tsw/44655']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Additive manufacturing', 'Ti64', 'SS 316L', 'Laser Powder Bed Fusion', 'X-ray Analysis', 'Keyhole', 'Marangoni Flow', 'Magnetic Fields']",X-Ray Analysis of Magnetically Induced Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/d06b32ff-a77c-43bc-b836-7d2330dc4be7/download,,"Through advancements in technology over the last several years, additive manufacturing has become 
increasingly mainstream in the manufacturing process. Additive manufacturing has several traits which would 
theoretically make it superior to traditional subtractive manufacturing techniques. While this ability to 
manufacture complex parts is certainly applicable to the external structure, additive manufacturing will allow for 
control over the internal structure of a part as well. From this, porous components can be created which match 
desired mechanical properties somewhat independently of the material actually used for manufacturing. However, 
many of these advancements require further refinement of the additive manufacturing processes intrinsic to them. 
One of the techniques suggested as a method of improving additive manufacturing processes is the incorporation 
of magnets into the manufacturing process. These magnets are used to direct the flow of the melted metal with 
more precision. Experiments were conducted in order to evaluate the effects of the introduction of magnets on 
parts printed using Laser Powder Bed Fusion. Stainless steel 316L, a relatively cheap and easy to print steel, was 
printed onto a Ti64 substrate using both spot welding and line scanning. It was observed that magnets had an 
effect on the melt pool and the keyhole depth through an analysis of the spot welding. Additionally, the various 
magnets also changed the flow of particles in the melted areas generated through line scanning. While quantifying 
the magnetic fields' effects will require additional research and time, there is strong evidence that they could be a 
viable solution to increasing additive manufacturing’s precision.",,,,,,
"['Lau, Wing', 'Bradbury, Tom', 'Youssef, Adolphe', 'Gaylo, Chris', 'Sun, Wei', 'Lau, Alan']",2019-10-23T15:07:30Z,2019-10-23T15:07:30Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/76754', 'http://dx.doi.org/10.26153/tsw/3843']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Heterogeneous,XML Representation and Process Algorithm for Layered Manufacturing of Heterogeneous Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/47aba2f1-b397-4876-9d1d-577005e631b4/download,,"In the fast developing technology of solid freeform fabrication, it remains a challenge to
fabricate a heterogeneous object by layered manufacturing because conventional CAD systems
and STL databases do not contain material and manufacturing information. This paper presents a
novel approach to layered manufacturing of heterogeneous objects. A new processing algorithm
based on the Extensible Markup Language (XML) format is being developed to process
heterogeneous objects for layered manufacturing. The model database containing geometry,
topology, material and manufacturing information is described by XML structural elements with
the hierarchy analogized to the TREE data structure of the Boundary Representation (B-Rep)
and/or the Constructive Solid Geometry (CSG) model. A process model for layered
manufacturing is formulated based on the XML format for the fabrication of heterogeneous
objects. A case study is presented to demonstrate the process algorithm for representing a multimaterial B-Rep model in the context of Three Dimensional Printing (3DP) technology.
Specifically, the case study will show the conversion of a solid model to XML representation, the
material assignment, the slicing, and the machine toolpath generation. The paper also presents a
brief survey of technological application of XML and associated technologies.",,,,,,
"['Weber, Daniel H', 'Zhou, Wenchao', 'Sha, Zhenghui']",2023-01-26T14:43:20Z,2023-01-26T14:43:20Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117309', 'http://dx.doi.org/10.26153/tsw/44190']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Cooperative 3D Printing', 'Swarm Manufacturing', 'Geometric Partitioning']",Z-Chunking for Cooperative 3D Printing of Large and Tall Objects,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8627e73e-2a3f-4e84-993a-dc9e2123638e/download,,"Cooperative 3D Printing (C3DP) is an emerging technology designed to address the size 
and printing speed limitations of conventional gantry-based 3D printers. To print large-scale 
objects, C3DP divides a job into chunks to be printed by a swarm of mobile robots. Previously, 
we developed a Chunker algorithm to partition jobs into printable parts in the XY direction, which 
theoretically enables the printing of objects of unlimited size in XY dimensions. However, print 
size is limited in the Z direction due to the physical constraints of the printer. In this paper, we 
introduce the first working strategy and rules of Z-Chunking for C3DP, such as where and how to 
place chunk boundaries along the Z direction and alignment geometries for easy post-assembly. 
Additional challenges of interfacing with XY chunking and facilitating re-assembly of the job are 
also considered. We conduct two case studies on objects of varying geometric complexity (e.g., 
simple solids vs. hollow structures) in which the object is chunked, printed, and assembled.",,,,,,
"['Duty, Chad', 'Failla, Jordan', 'Kim, Seokpum', 'Smith, Tyler', 'Lindahl, John', 'Roschli, Alex', 'Post, Brian', 'Love, Lonnie', 'Kunc, Vlastimil']",2021-11-16T15:24:17Z,2021-11-16T15:24:17Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90312', 'http://dx.doi.org/10.26153/tsw/17233']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['z-pinning', 'mechanical anisotropy', '3D printed parts', '3D printing']",Z-Pinning Approach for Reducing Mechanical Anisotropy of 3D Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e1b2ea0e-60b8-4f31-bd70-3eace978ba21/download,University of Texas at Austin,"The mechanical strength of extrusion-based printed parts is often greatly reduced (25-50%) in
the build direction (z-direction) compared to the in-plane strength due to poor bonding between
successively deposited layers. This effect can be magnified (75-90% difference) when depositing
fiber-reinforced materials or larger print areas with long layer times. Therefore, a patent-pending
approach has been developed that deposits material into intentionally aligned voids in the z-direction, allowing continuous material to span multiple layers. The “z-pinning” approach can be
applied to several concepts for improving the interlaminar strength of extrusion-based 3D printed
parts as well as techniques for applying the technology across a broad spectrum of deposition
platforms and material systems. Initial experimental results demonstrate a significant
improvement (>3x) in mechanical strength and (>8x) toughness for fiber reinforced components.",,,,,,
"['Stucker, Brent', 'Bradley, Walter', 'Eubank, P.T.', 'Norasetthekul, Somchintana', 'Bozkurt, Bedri']",2018-11-30T15:22:52Z,2018-11-30T15:22:52Z,1997,Mechanical Engineering,doi:10.15781/T2ZW19C36,http://hdl.handle.net/2152/70593,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['EDM', 'ZrB2 powders']",Zirconium Diboride/Copper EDM Electrodes From Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6118fdcf-a80d-4285-a290-6f8909035383/download,,,,,,,,
"Bibas, C.",2021-12-07T18:08:50Z,2021-12-07T18:08:50Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90742', 'http://dx.doi.org/10.26153/tsw/17661']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['Øgon', 'lens free optical scanner', 'LFOS', 'additive manufacturing']","Øgon, A Revolutionary New Lens Free Optical Scanner (LFOS) for Additive Manufacturing",Conference paper,https://repositories.lib.utexas.edu//bitstreams/ac81482a-5b8e-4e2f-bbd8-6e01043f0805/download,University of Texas at Austin,,,This paper describes the optics of the Øgon™ and compares it head to head with the GS.,,,,
"['Roy, N.K.', 'Cullinan, M.A.']",2021-10-19T18:11:26Z,2021-10-19T18:11:26Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89314,eng,2014 International Solid Freeform Fabrication Symposium,Open,"['nanopowders', 'powder spreading', 'actuating system', 'powder bed', 'μ-SLS']","μ-SLS of Metals: Design of the Powder Spreader, Powder Bed Actuators and Optics for the System",Conference paper,https://repositories.lib.utexas.edu//bitstreams/e7c270bf-07d5-4ac4-8554-3b5ac721e8ca/download,University of Texas at Austin,"Nanopowders have a tendency to form agglomerates due to high surface energy and the
presence of attractive van der Waals forces. To overcome this problem, we present a powder
spreading mechanism design that can alleviate this phenomenon by using vibration compaction
to produce a uniform powder distribution in the bed. Most SLS machines employ either a roller
or a blade to spread the powder over the powder bed. However, in order to achieve layer
thicknesses of few microns, a new design for the spreading mechanism which includes a
combination of a precision blade and a precision roller is employed. Also, the design of a linear
actuating system for displacing the powder bed with resolution of few tens of nanometers is
presented for the μ-SLS system. Finally, the paper presents a novel optical system that can
drastically increase the throughput of the system .The detailed design of these systems are
presented in this paper.",,,,,,
"['Roy, N.K.', 'Yuksel, A.', 'Cullinan, M.A.']",2021-10-20T22:33:47Z,2021-10-20T22:33:47Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89377,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['micro-scale selective laser sintering', 'μ-SLS', 'nanopowders', 'copper', 'particle size', 'density']",μ-SLS of Metals: Physical and Thermal Characterization of Cu- Nanopowders,Conference paper,https://repositories.lib.utexas.edu//bitstreams/44872607-430d-4595-8cb4-37740d20f7ba/download,University of Texas at Austin,"Micro-scale selective laser sintering(μ-SLS) requires the use of nanoparticles(NPs) since
the particle size needs to be an order of magnitude smaller than the melt pool in order to
accurately sinter particles together to form a part. Most NPs properties are dependent upon size
and thus, an exhaustive study of the physical and thermal properties of these NPs is required in
order to successfully model and simulate the sintering process. In this paper we will present
particle size characterization using Scanning electron microscopy (SEM), density measurements
using He pycnometry, and X-ray Energy Dispersive Spectroscopy that were carried out to
characterize the copper(Cu) nanopowder samples. Furthermore, the samples were sintered with
different powers to estimate optimum power and exposure times and the results have been
discussed along with further scope of work for fully characterizing the particles.",,,,,,
"['Wächter, Julian', 'Elsner, Maike', 'Moritzer, Elmar']",2021-11-18T01:51:17Z,2021-11-18T01:51:17Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90401', 'http://dx.doi.org/10.26153/tsw/17322']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['PEEK', 'processability', 'weld seam strength', 'fused deposition modeling']",Investigation of the Processability of Different PEEK Materials in the FDM Process with Regard to the Weld Seam Strength,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a36b468c-7062-476b-87f8-582433c28b95/download,University of Texas at Austin,"Due to the great popularity of the Fused Deposition Modeling (FDM) process, the material market is
growing. In particular, processing of high-temperature materials such as PEEK is demanding.
The aim of the investigations is to test different PEEK materials regarding their processability in the FDM process.
An unreinforced PEEK, a thermally conductive PEEK as well as a carbon fiber reinforced PEEK are investigated.
The processability is assessed with the help of the weld seam strength. The assessment of the weld seam strength
is carried out by building tests. For this purpose, a special method developed at the DMRC is used. In addition, a
welding width factor between the strands deposited on each other is calculated and compared. Finally, a welding
factor is determined to enable the comparison between the different materials. With this procedure, the influences
of varying nozzle and build chamber temperatures on the achievable weld seam strengths are evaluated.",,,,,,
"['Wimmer, Marco', 'Kemnitzer, Jan', 'Forster, David', 'Schorzmann, Johann', 'Dopper, Frank']",2024-03-25T22:24:38Z,2024-03-25T22:24:38Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124320', 'https://doi.org/10.26153/tsw/50928']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['HSS', 'PBF-P', 'PEBA', 'additive manufacturing']",Investigation of the Processability of Polyether Block Amide in High Speed Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/676a37fd-aab9-4e08-832f-4c0d8c96a018/download,University of Texas at Austin,"The High Speed Sintering (HSS) process ranks among the processes of Powder Bed
Fusion of polymers (PBF-P) of Additive Manufacturing (AM). Its scalability, constant layer
time and high quality of complex parts compared to other AM processes are some of the
characteristics of the HSS showing its potential for series production for small to medium series.
Most of the investigations for the PBF-P processes were conducted using commercially
available materials like Polyamide 12 (PA12), Polyamide 6 (PA6), Thermoplastic polyurethane
(TPU), Polypropylene (PP) and Polybutylene terephthalate (PBT). This work reports from the
processing of Polyether block amide (PEBA) in HSS. As a block-copolymer on amide basis,
PEBA shows higher performance compared to other block-copolymers like TPU: The high
elastic properties, low density and high service temperature make PEBA an ideal material for
the use in the athletic footwear and outdoor industry. Until now, no research was conducted on
processing PEBA powder in HSS. This work focusses on the material analysis of PEBA powder
and manufacturing of specimens of varying sets of process parameters using methods of Design
of Experiments (DoE) and IFINAM TPA powder from Evonik. Based on a predictive model,
parameter sets for optimum mechanical properties, dimensional accuracy and overall part
properties of HSS PEBA parts were optimised within the framework of this work.",,,,,,
"['Ravichander, B.B.', 'Farhang, B.', 'Ganesh-Ram, A.', 'Hanumantha, M.', 'Ramachandra, S.', 'Shinglot, Y.', 'Amerinatanzi, A.', 'Shayesteh Moghaddam, N.']",2021-12-06T22:34:18Z,2021-12-06T22:34:18Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90700', 'http://dx.doi.org/10.26153/tsw/17619']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['laser powder bed fusion', 'reinforcement', 'IN718', 'microstructure', 'Vickers hardness']",Investigation of the Properties of Reinforced IN718 Structures Fabricated using Laser Powder Bed Fusion,Conference paper,https://repositories.lib.utexas.edu//bitstreams/25885333-3604-4965-88c2-b64a4f0031b7/download,University of Texas at Austin,"Inconel 718 (IN718) superalloy, known for its high strength and corrosion resistant behavior, is
widely used in the aerospace and automotive industries. Laser power bed fusion (LPBF), one of
the commonly used techniques of additive manufacturing, enables the fabrication of structures
with a variety of local properties. Using the same material, components with spatially varying
properties can be fabricated through applying different processing parameters. In this study, IN718
composite structures were fabricated using four types of rod reinforcements with different
geometry. A different set of process parameters was used to fabricated reinforcing rods compared
to that of the main part. The bonding quality at the interface between the main part and
reinforcements was determined by defect analysis on the microstructure results. Also, Vickers
hardness test was performed at the interface in order to examine the mechanical properties of the
samples. It was found out that a similar level of densification and hardness value, slightly less than
the plain sample, can be achieved using helical and arc reinforcing rods. By contrast, significantly
lower density and hardness were observed for the sample reinforced by square rods compared to
the plain sample.",,,,,,
"['Zhou, Y.', 'Zhou, X.', 'Teng, Q.', 'Wei, Q.S.', 'Shi, Y.S.']",2021-10-20T21:53:28Z,2021-10-20T21:53:28Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89371,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', '316L stainless steel', 'Inconel 718', 'functionally graded materials', 'powder bed', 'powder feed']",Investigation of the Scan Strategy and Property of 316L Stainless Steel-Inconel 718 Functionally Graded Materials Fabricated by Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4883d255-505a-4a17-ba72-520e877df0fc/download,University of Texas at Austin,"316L stainless steel and Inconel 718 alloy functionally graded materials were
fabricated by selective laser melting with a novel approach which combined powder-bed with powder-feed pattern. Two different scanning strategies have been used to form
the steel/Ni FGMs. The interfacial characteristics were analyzed by scanning electron
microscopy and energy dispersive spectroscopy. Quantitative evidence of good bonding
at the interface was obtained from the tensile and shear tests of the steel/Ni FGMs.",,,,,,
"['Yang, Li', 'Haijun, Gong', 'Dilip, Samuel', 'Stucker, Brent']",2021-10-13T21:02:45Z,2021-10-13T21:02:45Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88784', 'http://dx.doi.org/10.26153/tsw/15718']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['thin features', 'direct metal laser sintering', 'lightweight structures', 'additive manufacturing']",An Investigation of Thin Feature Generation in Direct Metal Laser Sintering Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/067fe6bb-ad91-4a5b-aa22-6839005cfb61/download,University of Texas at Austin,"The fabrication of metal structures with thin features (<1mm) with additive manufacturing processes is
of interest for various lightweight applications. This paper investigates the geometrical and
microstructural characteristics of thin features fabricated using an EOS direct metal laser sintering
(DMLS) system. Both 1D and 2D thin features were fabricated using various process themes, and
subsequently analyzed for microstructure geometrical characteristics. It was found that the selection of
process parameters has significant influence on both the geometrical accuracy and the microstructure of
the thin features. The results can be used for the further development of process guidelines for
lightweight structures such as cellular structures and support structures.",,,,,,
"['Fan, Foxian', 'Jalui, Sagar', 'Lajoie, Nicholas', 'Manogharan, Guha']",2023-02-10T14:27:02Z,2023-02-10T14:27:02Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117454', 'http://dx.doi.org/10.26153/tsw/44335']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['AM Post-Processing', 'AM Areal Surface Roughness', 'Mass Finishing', 'Centrifugal Disc Finishing', 'AM Wear Behavior', 'Hybrid Manufacturing']",Investigation of Wear Behavior of Centrifugal Disc Finishing on Additively Manufactured Ti6Al4V Samples,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef4d9b99-5f74-441d-a9dc-0660cbfba0d2/download,,"As-built Additively Manufactured (AM) metallic parts require secondary processing in 
most applications to improve surface finish and mechanical strength. Mass Finishing (MF) 
processes are gaining popularity as effective and economical surface improvement methods for 
metal AM parts. This study investigates the wear behavior of post-processing both Laser Powder 
Bed Fusion (LPBF) and Electron Beam Melting (EBM) fabricated Ti6Al4V parts via Centrifugal 
Disc Finishing (CDF). Both AM orientation-based surface finish and wear behavior are compared 
for better understanding on key mechanisms of AM+MF hybrid manufacturing system. The areal 
surface roughness results showed that wear rate on side surfaces were higher than top surfaces for 
both LPBF and EBM samples in CDF. In addition, LPBF samples exhibited higher material 
removal than EBM samples based on weight loss measurements.",,,,,,
"['Mollah, Md. Tusher', 'Moetazedian, Amirpasha', 'Gleadall, Andy', 'Yan, Jiongyi', 'Alphonso, Wayne Edgar', 'Comminal, Raphaël', 'Šeta, Berin', 'Lock, Tony', 'Spangenberg, Jon']",2023-01-26T15:51:41Z,2023-01-26T15:51:41Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117321', 'http://dx.doi.org/10.26153/tsw/44202']",eng,2022 International Solid Freeform Fabrication Symposium,Open,"['Microscale Corner Precision', 'Bowden and Direct-drive Extruders', 'Experiments', 'Computational Fluid  Dynamics', 'Material Extrusion Additive Manufacturing']",Investigation on corner precision at different corner angles in material extrusion additive manufacturing: An experimental and computational fluid dynamics analysis,Conference paper,https://repositories.lib.utexas.edu//bitstreams/333c6c2a-64c3-407c-84e3-e1b4c91ac515/download,,"This paper investigates the influence of different corner angles on microscale geometry in material extrusion 
additive manufacturing. Polylactic acid (PLA) was 3D-printed with corner angles of 15°, 30°, 45°, 60°, 75°, 90°, 
and 135° using Bowden and Direct-drive extruders. A computational fluid dynamics (CFD) model was developed 
to simulate the polymer flow through the extrusion nozzle of both extruders. The simulated corner geometries 
were compared with experiments to assess simulation accuracy. This included the primary and secondary mitre 
cross-sectional width through the corner point of the 3D-printed strands. This enabled a new understanding about 
the prediction accuracy of the CFD model as well as the state of material at the corners, and the deviation of 
experimental and simulated corners from the analytical one. Moreover, the amount of over- and under-extrusion 
around the corner was estimated for experimental and simulated studies compared with the analytical corner, 
which provided fundamental knowledge on corner precision for angular print paths.",,,,,,
"['Yasa, Evren', 'Deckers, Jan', 'Craeghs, Tom', 'Badrossamay, Mohsen', 'Kruth, Jean-Pierre']",2021-09-28T19:19:35Z,2021-09-28T19:19:35Z,9/15/09,Mechanical Engineering,,"['https://hdl.handle.net/2152/88158', 'http://dx.doi.org/10.26153/tsw/15099']",eng,2009 International Solid Freeform Fabrication Symposium,Open,"['selective laser melting', 'elevated ridges', 'elevated edges', 'successive layers']",Investigation on Occurrence of Elevated Edges in Selective Laser Melting,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8e3b3ebd-22bb-433a-83b9-a918b3a27871/download,University of Texas at Austin,"Selective laser melting (SLM) is a layer-wise material additive process for the direct
fabrication of functional metallic parts. During the process, successive layers of metal powder are
fully molten and consolidated on top of each other by the energy of a high intensity laser beam.
The process is capable of producing almost fully dense three-dimensional parts having
mechanical properties comparable to those of bulk materials. However, one of the problems
encountered in SLM process is the occurrence of elevated ridges of the solidified material at the
edges of the successive layers. Those ridges reduce the dimensional accuracy and topology of the
top surface. The edge-effect problem is encountered not only in SLM, but also in other
production techniques applying melting processes such as LENS® (The Laser Engineered Net
Shaping) and EBM (Electron Beam Melting). In this study, the reasons for elevated edges and
solutions to this problem are investigated and reported. Different scan strategies as well as
different hatching and contour parameters are tested to reduce the edge-effect problem. Besides,
the influence of applying laser re-melting in combination to selective laser melting has been
investigated. It turns out that re-melting layers deposited by SLM improves the part density and
surface roughness, but creates on its own elevated edges.",,,,,,
"['Deng, Dongping', 'Chen, Yong', 'Zhou, Chi']",2021-10-06T20:42:30Z,2021-10-06T20:42:30Z,2012,Mechanical Engineering,,"['https://hdl.handle.net/2152/88439', 'http://dx.doi.org/10.26153/tsw/15376']",eng,2012 International Solid Freeform Fabrication Symposium,Open,"['PEEK composite', 'mask projection stereolithography', 'slurry recoating', 'sintering']",Investigation on PEEK Fabrication Using Mask-image-projection-based Stereolithography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/cfe87725-aa7a-428c-aff0-83c49414c95b/download,University of Texas at Austin,"This paper presents the findings of an initial study of the fabrication of polyetheretherketone (PEEK)
components based on the mask-image-projection-based Stereolithography (MIP-SL) process. PEEK is a
semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are
retained to high temperatures. It has been extensively used in the aerospace, automotive, biomedical, and
chemical process industries. The fabrication process based on the MIP-SL includes both green-part
fabrication and the sintering of fabricated green parts. In the green part fabrication, the challenges of
recoating viscous composite slurry are discussed. A prototype system has been developed for the
fabrication of green-parts with complex shapes and small features. Based on the fabricated green-parts,
the challenges in the sintering process for achieving desired functionality are discussed. The test results
on the sintered PEEK components have also been presented. Future work based on the study has been
identified.",,,,,,
"['Praniewicz, M.', 'Fox, J.', 'Saldana, C.']",2021-12-01T23:17:39Z,2021-12-01T23:17:39Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90652', 'http://dx.doi.org/10.26153/tsw/17571']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['lattice structures', 'definition', 'qualification', 'additive manufacturing']",An Investigation on the Definition and Qualification of Form on Lattice Structures,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c6721a9d-53b6-4402-872a-1d0c0f0fc69d/download,University of Texas at Austin,"The lack of uniform qualification techniques for additively manufactured components throughout
industry currently limits their application in high risk environments. This stems from a shortage
of proper tolerancing and product definition to convey design intent and required qualification.
This definition is particularly difficult for complex lattice geometries. The results of studies in
which the form of a lattice component is defined by theoretical supplemental surfaces are
summarized, with specific attention to the role of data sampling in the evaluation of form. A new
case study is presented where techniques borrowed from surface metrology, namely the
construction of a bearing area curve, are used to evaluate the sampling cutoff for form
evaluation. This method is first validated on the nominal geometry of three lattice designs. Initial
results indicate this as a promising methodology.",,,,,,
"['Liu, Bochuan', 'Tuck, Christopher', 'Saleh, Ehab', 'Ashcroft, Ian', 'Wildman, Ricky', 'Hague, Richard']",2021-10-12T20:30:54Z,2021-10-12T20:30:54Z,2014,Mechanical Engineering,,"['https://hdl.handle.net/2152/88734', 'http://dx.doi.org/10.26153/tsw/15668']",eng,2014 International Solid Freeform Fabrication Symposium,Open,"['multi-functionality', 'multi-layer', 'conductive tracks', 'inkjet printing']",Investigation on the Performance of Multi-Layer Printed Conductive Tracks on Multi-Layer Printed Insulator,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b9c4f77b-7150-4eff-bd37-457f16051091/download,University of Texas at Austin,"The move to multi-functionality in Additive Manufacturing converges a number of
technical challenges, notably the accurate and reliable deposition of different
materials and their interaction. In this paper, an investigation on the pattern quality
and conductivity of multi-layer printed conductive tracks on multi-layer 3D printed
insulator was carried out using a drop-on-demand inkjet technique. Results have
shown that the surface finish of the printed insulator had a significant effect on the
performance of the conductive tracks that have been overlaid. Also the printing
strategy used in the processing resulted different width, height, conductivity and
pattern quality of multi-layer printed conductive tracks.",,,,,,
"['Goulas, Athanasios', 'Southcott-Engstrøm, Daniel', 'Friel, Ross J.', 'Harris, Russell A.']",2021-11-01T22:03:04Z,2021-11-01T22:03:04Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89772,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['extra-terrestrial materials', 'additive manufacturing', '3D printing']",Investigation the Additive Manufacture of Extra-Terrestrial Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3dcf26af-83a2-4ccf-bf84-814aa324b829/download,University of Texas at Austin,"The Powder Bed Fusion (PBF) additive manufacturing process category, consists of a
group of key enabling technologies allowing the fabrication of both intrinsic and complex
structures for a series of applications, including aerospace and astronautics. The purpose of this
investigation was to explore the potential application of in-space additive manufacturing/3D
printing, for onsite fabrication of structures and parts, using the available extra-terrestrial natural
resources as feedstock. This study was carried out by using simulants of terrestrial origin,
mimicking the properties of those respective materials found extra-terram (in space). An
investigation was conducted through material characterisation, processing and by powder bed
fusion, and resultant examination by analytical techniques. The successful realisation of this
manufacturing approach in an extra-terrestrial environment could enable a sustainable presence in
space by providing the ability to build assets and tools needed for long duration/distance missions
in deep space.",,,,,,
"['Liu, Bochuan', 'Wildman, Ricky', 'Tuck, Christopher', 'Ashcroft, Ian', 'Hague, Richard']",2021-10-04T21:24:29Z,2021-10-04T21:24:29Z,2011,Mechanical Engineering,,"['https://hdl.handle.net/2152/88351', 'http://dx.doi.org/10.26153/tsw/15290']",eng,2011 International Solid Freeform Fabrication Symposium,Open,"['particle size distribution', 'powder bed', 'processing paramters', 'quality of finishing parts', 'Selective Laser Melting']",Investigation the Effect of Particle Size Distribution on Processing Parameters Optimisation in Selective Laser Melting Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/c1438596-fbb8-4e28-ada8-6fa82077e1c5/download,University of Texas at Austin,"Selective Laser Melting is an efficient process for producing metal parts with minimal subtractive
post-processing required. Analysis of the parameters controlling the part quality has been
performed focusing on the energy intensity during processing and the effect of the particle size
distribution on factors such as ultimate tensile strength and surface finish. It is shown that the
controlling the energy intensity is key to quality and can be affected by varying, for example,
laser beam diameter or the scanning rate.",,,,,,
"['Weiss, C.', 'Munk, J.', 'Haefner, C.L.']",2021-12-06T21:53:56Z,2021-12-06T21:53:56Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90686', 'http://dx.doi.org/10.26153/tsw/17605']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['powder behavior', 'AlSi10Mg', 'recyclability', 'laser powder bed fusion', 'LPBF']",Investigation Towards AlSi10Mg Powder Recycling Behavior in the LPBF Process and Its Influences on Mechanical Properties,Conference paper,https://repositories.lib.utexas.edu//bitstreams/63f96a6f-f108-4ad9-b635-fd3e303a3aa0/download,University of Texas at Austin,"Parts fabricated by Laser Powder Bed Fusion (LPBF) technique allow for a high
material utilization of a single powder batch, since unfused powder material can be reconditioned
and reused in subsequent manufacturing jobs. Due to process induced spatters however, the
quality of the powder may change during recycling, which in turn can affect the mechanical
properties of built parts. Therefore, a better understanding on the recyclability of the powder
material is needed. Within this work, the powder ageing behavior of the lightweight aluminum
alloy AlSi10Mg in the LPBF process is investigated. A standard build job is developed and built
with ageing powder in 10 consecutive jobs with no refreshing between the cycles. The powder
properties as well as the mechanical properties at static load for two different build
orientations are investigated. The comprehensive analyses suggest that the powder coarsening
may lead to improved mechanical properties during recycling for AlSi10Mg.",,,,,,
"['Krischke, N.', 'Friedmann, M.', 'Fleischer, J.']",2023-03-30T16:18:03Z,2023-03-30T16:18:03Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117701', 'http://dx.doi.org/10.26153/tsw/44580']",eng,2022 International Solid Freeform Fabrication Symposium,Open,ARBURG,Investigations for the Optimization of Metal Freeforming using the ARBURG freeformer,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3d704f8a-532b-4bc3-b8e5-808b1fd8e24e/download,,"The ARBURG freeformer represents an additive manufacturing system for producing 
thermoplastic components using commercially available polymer granulate. This fabrication 
process offers the potential to use feedstocks known from the metal injection molding (MIM) sector 
to manufacture so-called green parts. These parts consist of 60 Vol.-% stainless steel powder and 
40 Vol-% organic polymer binding system. By debinding and sintering these green parts, it is 
possible to economically produce full metal components with mechanical properties comparable 
to metal injection molding. In this publication, the process of producing stainless steel parts with 
ARBURG plastic freeforming will be presented. The mechanical properties and part density are 
optimized by varying manufacturing parameters and raw materials. Furthermore, concepts to 
optimize and increase the service life of the nozzle are shown and discussed. An increase of at least 
250% could be achieved by plasma nitriding and coating components of the discharge system.",,,,,,
"['Hecker, F.', 'Elsner, C.L.', 'Hirsch, A.', 'Moritzer, E.']",2021-12-01T23:04:41Z,2021-12-01T23:04:41Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90648', 'http://dx.doi.org/10.26153/tsw/17567']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['arburg plastic freeforming', 'visual properties', 'geometrical properties', 'process parameters', 'optimization']",Investigations for the Optimization of Visual and Geometrical Properties of Arburg Plastic Freeforming Components,Conference paper,https://repositories.lib.utexas.edu//bitstreams/8d15d057-264b-41ff-8ac5-beaa5df1ebe2/download,University of Texas at Austin,"Arburg Plastic Freeforming (APF) is an additive manufacturing process with which three-dimensional, thermoplastic components can be produced layer by layer. Visual and geometrical
properties are a major criterion for characterizing the resulting component quality. The aim of
this study was to investigate the influences on visual and geometrical properties of APF
components depending on process parameters. Initially the focus was on the analysis of the
shrinkage behavior of ABS-M30 (Stratasys). On the basis of the results and an existing
procedure by the machine manufacturer, an optimized procedure for determining the scaling
factors was developed to counteract the shrinkage. With this procedure a higher dimensional
accuracy of the components can be achieved. In addition, it was investigated whether an
adaption of the form factor based on a mathematical model depending on the component
geometry makes sense. The results were transferred into manufacturing guidelines, which allow
the user of the APF-technology to optimize process parameters more efficiently.",,,,,,
"['Jiang, Jinhui', 'Yuan, Mengqi', 'Ji, Tingchao']",2021-11-01T21:35:32Z,2021-11-01T21:35:32Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89761,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['stab resistance body armor', 'laser sintering', 'structure', 'pyramid']",Investigations on Laser Sintered Textiles for Stab-Resistant Application,Conference paper,https://repositories.lib.utexas.edu//bitstreams/f1697458-0b40-4329-8b39-da37a80d3612/download,University of Texas at Austin,"Stab resistance body armor (SRBA) is essential in protecting people from knife injuries. The
protective parts of traditional SRBA are made of multi-layered ultra-high molecular weight
polyethylene, which causes heavy heat stress for people wearing it. In this paper, the protective
parts of SRBA were manufactured using laser sintering (LS) technology, which provide high
manufacturing flexibility as well as high wearing comfort. Two different structures were
investigated, one is squared plate and the other is pyramid. It was found the pyramid structure
showed much higher stab resistance property then the plate, which is a result from the angle and
thickness effects. This paper is the first effort applying the technology of LS and material of PA
3200 on SRBA, and by applying the pyramid structure on the protective layer of the SRBA, the
total weight could reduce 30-40%.",,,,,,
"['Vora, P.', 'Derguti, F.', 'Mumtaz, K.', 'Todd, I.', 'Hopkinson, N.']",2021-10-11T20:34:34Z,2021-10-11T20:34:34Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88634', 'http://dx.doi.org/10.26153/tsw/15568']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['Additive Manufacturing', 'Selective Laser Sintering', 'Electron Beam Melting', 'metal powder bed', 'in-situ alloy', 'semi-solid processing']",Investing a Semi-Solid Processing Technique Using Metal Powder Bed Additive Manufacturing Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/306d6f58-a927-41df-a64a-8d4e64d27cf6/download,University of Texas at Austin,"The work reported investigates in-situ alloying using a semi-solid processing technique with metal
powder bed Additive Manufacturing (AM); in this instance Selective Laser Melting (SLM) and
Electron Beam Melting (EBM) were employed. This technique utilised customised powder blends
that were processed at elevated temperatures. The selection of processing temperature considered
specific alloy solidification ranges. As a result, parts with reduced residual stresses can be produced.
In addition, the use of customised powder blends explored the feasibility of developing alloys specific
to the process/application, thus increasing available material ranges for AM metal powder bed
processes.",,,,,,
"['Zhang, Wei', 'Leu, Ming C.', 'Feng, Chao', 'Ren, Rong', 'Zhang, Renjie', 'Lu, Qingping', 'Jiang, Jubu', 'Yan, Yongnian']",2019-09-20T18:10:13Z,2019-09-20T18:10:13Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75921', 'http://dx.doi.org/10.26153/tsw/3020']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Prototyping,Investment Casting with Ice Patterns Made by Rapid Freeze Prototyping 66,Conference paper,https://repositories.lib.utexas.edu//bitstreams/82130586-75c0-4c20-8897-357fc53652fb/download,,"One of the most promising applications of rapid freeze prototyping (RFP) is making metal parts by investment casting with the built ice parts. The integration of RFP and investment casting allows fast creation of complex net-shape metal parts directly from their CAD models. The advantages of doing so include no part geometric complexity limitation, no experience of parting line design and assembling needed, clean and low-cost of process operation, and good performance. In this paper, we will present our recent study on binder selection, slurry making, ceramic shell making, and the casting results of the metal parts.",,,,,,
"['Lombardi, John L.', 'Hoffinan, Robert A.', 'Waters, Jason A.', 'Popovich, Dragan']",2018-12-05T20:35:18Z,2018-12-05T20:35:18Z,1997,Mechanical Engineering,doi:10.15781/T20K26X7N,http://hdl.handle.net/2152/71415,eng,1997 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'EFF']",Issues Associated with EFF & FDM Ceramic Filled Feedstock Formulation,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6207970d-7d8d-4791-b1ad-e2670ba99380/download,,,,,,,,
"['Paggi, Umberto', 'Ranjan, Rajit', 'Thijs, Lore', 'Ayas, Can', 'Langelaar, Matthijs', 'van Keulen, Fred', 'van Hooreweder, Brecht']",2021-11-18T18:50:12Z,2021-11-18T18:50:12Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90465', 'http://dx.doi.org/10.26153/tsw/17386']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['support structures', 'contactless support', 'overheating', 'downfacing regions', 'laser powder bed fusion']",New Support Structures for Reduced Overheating on Downfacing Regions of Direct Metal Printed Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/6e17ba55-1200-4e93-bbc5-83f299542d11/download,University of Texas at Austin,"In Laser Powder Bed Fusion (LPBF), the downfacing surfaces usually have increased surface
roughness and reduced dimensional accuracy due to local overheating and warpage. To partially
overcome this a new supporting structure is developed in this study, namely the contactless
support. This is a thin blade parallel to the critical area which transfer the heat away from the melt
pool via conduction through the powder bed instead of direct contact. The support is tested in
different geometries and printing conditions to define the optimal distance from the part and its
effectiveness is evaluated by measuring the surface roughness of the samples. Numerical
modelling of heat transfer phenomenon is also employed to determine the thermal history of the
printing process and understand which parameters define the optimal distance for the thermal
supports. Finally topology optimization is used to create a support structure which minimize the
wasted material while keeping the heat flow optimal.",,,,,,
"['Jandric, Z.', 'Kovacevic, R.']",2019-10-09T16:20:52Z,2019-10-09T16:20:52Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76154', 'http://dx.doi.org/10.26153/tsw/3243']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Optimization,New Way of Process Parameters Optimization in SFF Based on Deposition by Welding,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4e244c3-026a-4c9d-8b38-bebdf2a07a25/download,,"To successfully control the welding process and to make it appropriate for solid freeform
fabrication (SFF), it is necessary to fully understand the influence of the welding parameters and
the geometry of the substrate on the resulting weld bead dimensions. Extensive experiments
with different welding parameters and complex geometrical features such as edges and corners
have been designed and completed. The experimental data show a clear correlation between the
heat input, the weld bead dimensions, and the two dimensional (2D) geometrical features. This
correlation may be used for on-line welding process control. It is found that the geometry of the
molten pool is directly related to the heat transfer conditions determined by surrounding mass of
material. A machine vision system based on a high-resolution CCD camera coaxially integrated
with a gas tungsten arc welding (GTAW) torch is used to acquire the images of the molten pool.
The results demonstrate the capability to adjust GTAW process parameters according to complex
external and internal geometrical features of the substrate. The heat loss affected by the
surrounding mass of material will be used to determine the optimal energy input.","This work was financially supported by THECB, Grant No. 003613-0022001999, NSF, Grants
No. DMI – 9732848 and DMI – 9809198, and the U.S. Department of Education, Grant No.
P200A-80806-98.",,,,,
"['Plocher, J.', 'Panesar, A.']",2021-11-09T19:55:13Z,2021-11-09T19:55:13Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90147', 'http://dx.doi.org/10.26153/tsw/17068']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['beam compliance', 'three-point bending', 'topology', 'fiber orientation', 'lightweight structures', 'fused deposition modeling', 'additive manufacturing']",Next-Generation Fibre-Reinforced Lightweight Structures for Additive Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9f9cd531-1f2d-41e9-abfa-fddec79ecbd5/download,University of Texas at Austin,"In an attempt to realise next-generation lightweight parts and to fully utilize the inherent design
freedom of AM, we propose a topology optimization based design procedure that includes the
anisotropic considerations for continuous fibre printing of variable stiffness composites. In this
paper, we aim to improve the normalized compliance of a beam in a three-point bending scenario,
using a skeletal reinforcement for a topology in which the change in fibre orientation is derived
from the medial axis information. FDM with a dual-nozzle system printing nylon and carbon fibre
filaments were utilized for fabrication. The toolpath i.e. reinforcement strategy available from the
commercial software Eiger® was chosen to imitate the proposed strategy. The numerical
investigation is complemented with experimental tests and a general benchmarking is conducted
using standard pedants. The results have shown improved specific flexural stiffness for samples
with skeletal reinforcement. The skeletal information is therefore considered as important tool for
the retrieval of fibre angles which align with the principle stresses and therefore allow for a more
efficient fibre placement in AM parts for future lightweight end-use parts.",,,,,,
"['Melvin III, Lawrence S.', 'Beaman Jr., Joseph J.']",2018-11-08T15:37:28Z,2018-11-08T15:37:28Z,1995,Mechanical Engineering,doi:10.15781/T2KK94Z19,http://hdl.handle.net/2152/69890,eng,1995 International Solid Freeform Fabrication Symposium,Open,"['selective laser sintering', 'intermediate temperature', 'powder application']",Nickel Applied for Selective Laser Sintering Using a Magnetic Field,Conference paper,https://repositories.lib.utexas.edu//bitstreams/1648bcb6-ba34-4694-94ea-e6df7f963c7a/download,,"Metal powder was applied for the Selective Laser Sintering
process using the sieve feed system and a magnetic field.
The magnetic field had a negative effect on final part quality
as measured by a reduction in final part density. This
negative effect is theorized to be due to the shape and orientation
ofthe magnetic field. It appears possible to change
the field to a benevolent orientation.",,,,,,
"['Yuan, Mengqi', 'Bourerll, David']",2021-10-07T15:47:13Z,2021-10-07T15:47:13Z,8/16/13,Mechanical Engineering,,"['https://hdl.handle.net/2152/88486', 'http://dx.doi.org/10.26153/tsw/15420']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['nitrogen flow', 'Laser Sintering', 'part bed surface temperature']",Nitrogen Flow Effects on Part Bed Surface Temperature during Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4ca23f1d-1030-4a1a-96d5-d7d4697db441/download,University of Texas at Austin,"The role of nitrogen flow rate was invested as it affects the surface temperature of a polymer
laser sintering part bin. A SinterStation 2500® was used for this study. The effect of nitrogen
chamber flow rates between 0.5 and 2.5 m3/hr was observed and compared to the results of a
computational fluids dynamics model. Increasing convective flow generates a uniform reduction
in the surface temperature, but it does not meaningfully reduce surface temperature gradients.
The part bin piston was modified to allow down drafting of nitrogen through the part bin. Down
drafting, while once considered to be effective in accelerating cooling at the end of builds, did
not have a significant effect on the surface temperature profile.",,,,,,
"['Dietrich, Stefan', 'Englert, Lukas', 'Pinter, Pascal']",2021-11-09T15:19:29Z,2021-11-09T15:19:29Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90091', 'http://dx.doi.org/10.26153/tsw/17012']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['porosity analysis', 'x-ray computed tomography', 'laser powder bed fusion', 'metal FFF']",Non-Destructive Characterization of Additively Manufactured Components Using X-Ray Micro-Computed Tomography,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7a7e5112-1f97-4c1f-b4bd-373b2c0b0b8c/download,University of Texas at Austin,"Quality control and microstructure characterization are essential corner stones of the process optimization
through the understanding of process-microstructure-relations in additive manufacturing. The scope of this
work is to investigate the relationships between porosity and the process parameters as well as component
geometry based on X-ray micro-computed tomography data and thus improving the ability for improved
process control. Using test geometries manufactured via laser beam manufacturing and metal fused filament
fabrication in combination with specialized image analysis and data fusion algorithms an extensive analysis of
pore morphology, position and orientation with respect to the printing path could be carried out. The results
show a clear connection between printing strategies as well as part geometry and allow for a direct connection
to mechanical performance characteristics determined by the pore architecture like for example fatigue and
failure behavior.",,,,,,
"['Albakri, Mohammed', 'Sturm, Logan', 'Williams, Christopher B.', 'Tarazaga, Pablo']",2021-10-21T19:42:10Z,2021-10-21T19:42:10Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89432,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['impedance-based monitoring', 'part abnormalities', 'additive manufacturing', 'quality control']",Non-Destructive Evaluation of Additively Manufactured Parts via Impedance-Based Monitoring,Conference paper,https://repositories.lib.utexas.edu//bitstreams/58deae40-a995-4137-a483-668276cf6580/download,University of Texas at Austin,"The ability of Additive Manufacturing (AM) processes to fabricate complex geometries is
somewhat hindered by an inability to effectively validate the quality of printed complex parts.
Furthermore, there are classes of part defects that are unique to AM that cannot be efficiently
measured with standard Quality Control (QC) techniques (e.g., internal porosity). Current QC
methods for AM are limited to either destructive evaluation of printed test coupons, or expensive
radiation-based scanners of printed parts for non-destructive evaluation. In this paper, the authors
describe their use of impedance-based structural monitoring to indirectly measure printed part
abnormalities. By bonding a piezoceramic (PZT) sensor to a printed part, the measured electrical
impedance of the PZT can be directly linked to the mechanical impedance of the part. By observing
deviations in the mechanical impedance of the part, as determined by this quick, non-intrusive
electrical measurement, one is able to detect the existence of part defects. In this paper, the authors
explore the effectiveness and sensitivity of the technique as a means for detecting of a variety of
defect types and magnitudes.",,,,,,
"['Nomoto, Sukeharu', 'Segawa, Masahito', 'Wakameda, Hiroshi']",2021-11-15T20:58:39Z,2021-11-15T20:58:39Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90269', 'http://dx.doi.org/10.26153/tsw/17190']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['multi-phase field method', 'non-equilibrium', 'thermodynamics', 'machine learning', 'stainless steel', 'solidification', 'additive manufacturing']",Non-Equilibrium Phase Field Model Using Thermodynamics Data Estimated by Machine Learning for Additive Manufacturing Solidification,Conference paper,https://repositories.lib.utexas.edu//bitstreams/9935fac7-2574-497a-a858-6cc43e24651b/download,University of Texas at Austin,"A multi-phase field method using finite interface dissipation model proposed by Steinbach et al. is applied
to simulate solidification microstructure evolution of stainless steel composition in the non-equilibrium condition
of high cooling rate and temperature gradient of additive manufacturing. The calculation is performed for quinary
system in order to simulate solidification of engineering composition. Thermodynamic calculation using
CALPHAD database in this multi-phase field method calculation is replaced by machine learning prediction
procedure to reduce calculation time. The microstructure evaluated by using machine learning parameter is good
agreement with one directly coupled with CALPHAD database. This calculation is approximately five times faster
than the direct CALPHAD calculation method. Finally, it is confirmed that this multi-phase field method can be
applicable to simulate non-equilibrium phase transformation of additive manufacturing condition with high
numerical stabilization.",,,,,,
"['Johnston, S.', 'Anderson, R.', 'Storti, D.']",2020-02-21T15:22:35Z,2020-02-21T15:22:35Z,8/3/05,Mechanical Engineering,,"['https://hdl.handle.net/2152/80061', 'http://dx.doi.org/10.26153/tsw/7083']",eng,2005 International Solid Freeform Fabrication Symposium,Open,powder materials,Non-isothermal Initial Stage Sintering Strain Model with Application to 316L Stainless Steel,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b05baddc-e3ba-4d21-a934-406ad7ff6630/download,,,,,,,,
"['Hoglund, Robert', 'Smith, Douglas E.']",2021-10-21T15:01:53Z,2021-10-21T15:01:53Z,2015,Mechanical Engineering,,https://hdl.handle.net/2152/89387,eng,2015 International Solid Freeform Fabrication Symposium,Open,"['Fused Deposition Modeling', 'topology optimization', 'material distribution']",Non-Isotropic Material Distribution Topology Optimization for Fused Deposition Modeling Products,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ef78ac66-bf37-42c9-91d4-497aaa849241/download,University of Texas at Austin,"Mechanical properties of products produced with the Fused Deposition Modeling (FDM)
process are known to be dependent on bead direction, especially when short fiber reinforcement
is added to the polymer filament feedstock. As a result, the structural performance of fiber-filled
FDM parts is expected to be improved by simultaneously computing preferred deposition
directions while optimizing the internal support structure. This paper presents a topology
optimization method for computing the material distribution within a fiber-reinforced polymer
composite FDM part that incorporates the non-isotropic mechanical properties of the bead
structure. Unlike the well-established homogenization topology optimization method which
determines pointwise orthotropic properties by increasing the complexity of the design problem,
our approach takes advantage of the simplicity of the SIMP method where the underlying
orthotropic orientation is assumed. Computed results show the effect that the orientation of fiber
filled bead orthotropic microstructure has on part topology for 2D FDM parts.",,,,,,
"['Sharma, Maharshi A.', 'Patterson, Albert E.']",2024-03-26T20:30:11Z,2024-03-26T20:30:11Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124397', 'https://doi.org/10.26153/tsw/51005']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['FFF process', 'extrusion-based additive manufacturing', 'control systems', 'dynamic modeling']",Non-Linear Dynamic Modeling of Cartesian-Frame FFF 3-D Printer Gantry for Predictive Control,Conference paper,https://repositories.lib.utexas.edu//bitstreams/e4625159-dac0-4e70-aaa5-458bc219d6dc/download,University of Texas at Austin,"This paper presents the development of a dynamic model of an FFF 3-D printer gantry (2-D) that is useful
for developing an open-loop predictive control system. This predictive control system based on the mechanics of the
system will help to reduce manufacturing defects by minimizing position error in the printing head. A six-dimensional
non-linear dynamic model of the printer gantry was derived using Newton-Euler method, followed by a Lagrangian
dynamic model to gain additional insight on energy transfer aspects and model validation. A state-space model of the
full system was developed for positioning and control. A detailed case-study of an example printer was completed in
MATLAB-Simulink to demonstrate the system model with comparisons from the analytical model and physical
characterization on a real printer. Finally, a few examples of passive control designs were illustrated for predictive
control development. It was concluded that dynamics-based predictive control is a promising, realistic, and practical
approach to controlling the dynamic error and dimensional error commonly seen with FFF machines.",,,,,,
"Chen, Yong",2020-03-09T14:25:05Z,2020-03-09T14:25:05Z,8/21/07,Mechanical Engineering,,"['https://hdl.handle.net/2152/80184', 'http://dx.doi.org/10.26153/tsw/7203']",eng,2007 International Solid Freeform Fabrication Symposium,Open,Stereolithography,Non-Uniform Offsetting and its Applications in Laser Path Planning of Sterolithography Machine,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7861f3c4-a9cb-4e63-b910-14c400f60277/download,,"Laser path planning is an important step in solid freeform fabrication processes such as
Stereolithography (SLA). An important consideration in the laser path planning is to compensate
the shape of laser beam. Currently the compensation is divided into two steps, Z-compensation
and X-Y compensation, and the shape of laser beam is assumed to be uniform for the whole
platform. In this research, we present a sampling based non-uniform offsetting method which
accounts for the different shapes of laser beam at various locations. We discuss the related steps
and algorithms. We demonstrate its effectiveness by using various test cases. Besides
improving the accuracy of SLA machine, non-uniform offsetting can also be applied to address
other accuracy issues caused by thermal and structural variations",,,,,,
"['du Plessis, Anton', 'Yadroitsava, Ina', 'Yadritsev, Igor']",2021-11-09T15:15:41Z,2021-11-09T15:15:41Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90090', 'http://dx.doi.org/10.26153/tsw/17011']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['micro computed tomography', 'microCT', 'bottlenecks', 'additive parts', 'additive manufacturing']",Nondestructive Micro-CT Inspection of Additive Parts: How to Beat the Bottlenecks,Conference paper,https://repositories.lib.utexas.edu//bitstreams/81203d6d-c4fc-40fd-a8ea-a8f5e3ea357c/download,University of Texas at Austin,"Micro computed tomography (microCT) is widely in use for the inspection of additively
manufactured parts. The main use of the technique is to detect unwanted voids inside the part.
However, the ability to detect these kind of defects is strongly affected by image quality, which is
often directly related to the scan time. Selecting fast scan settings (e.g. 5 minutes per part) can work
for many situations where major flaws need to be identified (such as large unmelted cavities), but
this may result in the missing of critical defects which are smaller, such as clustered metallurgical
pores or chains of fine voids between layers or tracks caused lack of fusion . An important defect
type which can be missed by fast scanning is small inclusions also. Possible ways of overcoming
this problem are discussed. After scanning, image analysis requires computing power, time and
skilled human interface for proper analysis. Reduction of the image analysis workflow is possible
using semi-automated analyses and the data size can be reduced using simple methods, including
removal of unwanted data outside the object, 8-bit data size and even .STL format outputs in some
cases. In this paper all the above is discussed in relation to reducing the bottlenecks (problems
causing delays in getting results and slowing the workflow) often associated with microCT.",,,,,,
"['Simeunovic, A.', 'Hoelzle, D.']",2021-11-15T21:15:48Z,2021-11-15T21:15:48Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90275', 'http://dx.doi.org/10.26153/tsw/17196']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['nonlinear model', 'linearized model', 'gray box model', 'direct-write printing', 'extrusion-based additive manufacturing']",Nonlinear and Linearized Gray Box Models of Direct-Write Printing Dynamics,Conference paper,https://repositories.lib.utexas.edu//bitstreams/928d2bf1-2c6e-477b-8c25-8819d1bc3abc/download,University of Texas at Austin,"Control of material metering in material extrusion based additive manufacturing
modalities, such as positive displacement direct-write, is critical for manufacturing accuracy. However, in positive displacement direct-write, transient flows are poorly controlled
due to capacitive pressure dynamics - pressure is stored and slowly released over time from
the build material and other compliant system elements, negatively impacting flow rate startups and stops. Thus far, modeling of these dynamics has ranged from simplistic, potentially
omitting key contributors to the observed phenomena, to highly complex, making usage in
control schemes difficult. Here, we present nonlinear and linearized models that seek to
both capture the capacitive and nonlinear resistive fluid elements of positive displacement
direct-write systems and to pose them as ordinary differential equations for integration into
nonlinear and linear control schemes. We validate our theoretical work with experimental
flow rate and material measurements across a range of extrusion nozzles and materials to address different feature sizes and diverse applications spanning tissue engineering, electronics
fabrication, and food science. As part of this experimental work, we explore the contribution
of the bulk system compliance and the build material compliance to these dynamics. We
show that all models accurately describe the measured dynamics, facilitating ease of integration into future nonlinear and linear control systems. Additionally, we show that while build
material compliance may be nearly entirely reduced through appropriate system design, the
compliance from build material alone is significant enough to require feedback control to
fully control material delivery.",,,,,,
"['Beyene, Shiferaw D.', 'Ayalew, Beshah', 'Pilla, Srikanth']",2021-11-18T02:08:06Z,2021-11-18T02:08:06Z,2019,Mechanical Engineering,,"['https://hdl.handle.net/2152/90408', 'http://dx.doi.org/10.26153/tsw/17329']",eng,2019 International Solid Freeform Fabrication Symposium,Open,"['NMPC', 'switching systems', 'UV curing', 'additive manufacturing', 'optimal time control']",Nonlinear Model Predictive Control of UV-Induced Thick Composite Manufacturing Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3f04c4a1-74b2-4f21-9904-c632a9b795ee/download,University of Texas at Austin,"In this paper the nonlinear model predictive control (NMPC) of UV-induced curing of composite material
for manufacturing of thick parts is proposed. The process involves layer-by-layer curing of thin composite
laminates to form thick part. The model for NMPC switches when a new layer is added to the existing layer. The
layer addition times are determined externally. The offline optimal control is used to determine the optimal time
and temperature profile which will give uniform cure distribution of a thick composite material. Once the
temperature trajectory and optimal time sequences are found, the NMPC is implemented for online control. The
objective is to determine theoretical optimal behavior (assuming the process measurement is available) which
will be used for online switching NMPC for tracking the reference temperature.",,,,,,
"['Brown, R.', 'Morgan, C.T.', 'Majewski, C.E.']",2021-11-11T15:38:38Z,2021-11-11T15:38:38Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90223', 'http://dx.doi.org/10.26153/tsw/17144']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['elastomeric material', 'characterization', 'testing', 'high speed sintering', 'HSS']",Not Just Nylon... Improving the Range of Materials for High Speed Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a9a38f02-ac38-4b34-bfe4-5b9e381714c7/download,University of Texas at Austin,"High Speed Sintering (HSS) is an emerging, recently commercialised Additive
Manufacturing (AM) process which uses an infrared absorbing ink and infrared lamp to
selectively sinter layers of polymer powder. Currently, Nylon 12 and its composites are used as
the default feedstock due to their large processing windows. However, to meet the increasing
variety of end use applications afforded by the benefits of AM, a wider range of materials must
be developed. This work presents the characterisation and testing of a new elastomeric material
for use in HSS. Parts were produced over a range of processing conditions, varying key
parameters such as part bed temperature, ink density and lamp speed. Performance indicators
including powder recovery, surface roughness and tensile data were evaluated over the range of
conditions tested and all indicated the material’s suitability for use as an HSS material.",,,,,,
"['Schmidt, J.', 'Sachs, M.', 'Fanselow, S.', 'Wirth, K.-E.', 'Peukert, W.']",2021-10-27T22:11:26Z,2021-10-27T22:11:26Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89630,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['selective laser beam melting', 'polymer powders', 'stirred media milling', 'rounding']",Novel Approaches for the Production of Polymer Powders for Selective Laser Beam Melting of Polymers,Conference paper,https://repositories.lib.utexas.edu//bitstreams/78b069a3-b39b-4765-a494-3f183b78eac9/download,University of Texas at Austin,"The opening of new fields of application of powder-based additive manufacturing methods like selective
laser beam melting of polymers currently is hindered by the limited availability of materials showing good
processability. So far, virtually only polyamides are available as optimized powder materials. Two innovative
methods for production of spherical polymer micro particles for selective laser melting are discussed: The first
approach, stirred media milling and rounding, is applicable for a variety of polymers. It will be exemplarily
discussed for polyesters and the dependency of product properties (particle size distribution, shape,
crystallinity) on the process parameters in the comminution and in the rounding step will be assessed. The
second method, melt emulsification, will be demonstrated for polypropylene. Moreover, the possibilities of dry
coating to tailor particle properties are illustrated. The influence of powder properties on the processability and
on the quality of the obtained devices is outlined.",,,,,,
"['Bandyopadhyay, Amit', 'Atisivan, Raj', 'Bose, Susmita']",2019-03-15T16:10:05Z,2019-03-15T16:10:05Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73686', 'http://dx.doi.org/10.26153/tsw/828']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Ceramic materials', 'high strength']",Novel Ceramics and Metal-Ceramic Composites via Fused Deposition Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7c860bc1-c6f3-4f81-a592-3721df5096dc/download,,"Indirect fused·· deposition process is utilized.·.. to ·fabricate controlled porosity ceramic
structures using alumina, mullite, zirconia, LSCF-perovskite, tricalcium phosphate and
hydroxyapatite, where pore size, pore shape and pore connectivity are varied from one end to
the other end of the parts. Some of these porous ceramics are then infiltrated with metals via
pressureless reactive metal infiltration to form novel metal-ceramic composites. Thispaper will
describe processing, structures of various porous and metal-infiltrated composites and their
physical and mechanical properties.",,,,,,
"['Hutton, Logan J.', 'Bartolai, Joseph']",2024-03-26T20:04:21Z,2024-03-26T20:04:21Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124385', 'https://doi.org/10.26153/tsw/50993']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['material extrusion', 'infill region', 'additive manufacturing']",Novel Concepts to Integrate Dense and Sparse Infill Regions in Material Extrusion AM Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/b7e146ac-d0b4-4c4a-a7e2-e3ccaeb2ee55/download,University of Texas at Austin,"Modern toolpath generation softwares, or “slicers,"" allow for multiple regions within a Material
Extrusion Additive Manufacturing produced part to be assigned different processing parameters,
including infill density. Contemporary slicers develop these different infill regions independently,
leading to discontinuities in the toolpaths at the region's boundaries. This work investigates the
effect these discontinuities have on part strength, and tests a variety of novel approaches to connect
infill regions in a continuous manner to improve part properties. Mechanical properties of parts
built by toolpaths generated using Ultimaker Cura and Slic3r are compared to those of parts built
using the novel build strategies presented in this work. The continuous and sequential novel build
strategies presented in this work show statistically significant mechanical property increases.",,,,,,
"['Ghazanfari, Amir', 'Li, Wenbin', 'Leu, Ming C.', 'Hilmas, Gregory E.']",2021-10-28T20:22:34Z,2021-10-28T20:22:34Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89690,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['3D printing', 'extrusion freeforming', 'fused deposition', 'robocasting', 'radiation drying']",A Novel Extrusion-Based Additive Manufacturing Process for Ceramic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0a02b858-4dd8-4d57-8fff-616c6e4c1595/download,University of Texas at Austin,"An extrusion-based additive manufacturing process, called the Ceramic On-Demand Extrusion
(CODE) process, for producing three-dimensional ceramic components with near theoretical
density is introduced in this paper. In this process, an aqueous paste of ceramic particles with a
very low binder content (<1 vol%) is extruded through a moving nozzle at room temperature. After
a layer is deposited, it is surrounded by oil (to a level just below the top surface of most recent
layer) to preclude non-uniform evaporation from the sides. Infrared radiation is then used to
partially, and uniformly, dry the just-deposited layer so that the yield stress of the paste increases
and the part maintains its shape. The same procedure is repeated for every layer until part
fabrication is completed. Several sample parts for various applications were produced using this
process and their properties were obtained. The results indicate that the proposed method enables
fabrication of large, dense ceramic parts with complex geometries.",,,,,,
"['Graff, K.F.', 'Short, M.', 'Norfolk, M.']",2021-09-29T22:47:40Z,2021-09-29T22:47:40Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88224', 'http://dx.doi.org/10.26153/tsw/15165']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['ultrasonic additive manufacturing', 'Very High Power Ultrasonic Additive Manufacturing System', 'ultrasonic power', 'EWI', 'Solidica™']",Very High Power Ultrasonic Additive Manufacturing (VHP UAM) for Advanced Materials,Conference paper,https://repositories.lib.utexas.edu//bitstreams/91056bef-026a-47ce-8626-cf6a2986f5d7/download,University of Texas at Austin,"To extend current ultrasonic additive manufacturing (UAM) to advanced materials, higher
speeds and larger parts, it was essential to greatly increase the process ultrasonic power. EWI,
with Solidica™, several industry, agency and academic partners, and support of Ohio’s Wright
Program, have developed a “Very High Power Ultrasonic Additive Manufacturing System” that
greatly extends current technology. A key part was the design of a 9.0 kW “push-pull”
ultrasonic system able to produce sound welds in materials such as Ti 6-4, 316SS, 1100 Cu and
Al7075. The VHP system can fabricate parts of up to 1.5m x 1.5m x 0.6m, with process and
software developments that enable forming contoured surfaces.",,,,,,
"['Santangelo, Michael', 'Silwal, Bishal', 'Purdy, Alexander']",2021-10-28T20:31:35Z,2021-10-28T20:31:35Z,2016,Mechanical Engineering,,https://hdl.handle.net/2152/89693,eng,2016 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'wire feed', 'hot-wire GTAW', 'ABAM']",Vibration Assisted Robotic Hot-Wire Gas Tungsten Arc Welding (GTAW) for Additive Manufacturing of Large Metallic Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4624afa2-3590-442c-8215-9f5853f3ee40/download,University of Texas at Austin,"Most of the metal additive manufacturing technologies are focused on high cost and high end applications.
There is in need, a low cost additive manufacturing technology suitable for low and high end metallic applications.
Robotic automated welding can be considered as an alternative to manufactured large scale metal parts with layer
by layer approach. However, many obstacles have to be overcome to make it viable technology in additive
manufacturing industry. A Robotic hot-wire Gas Tungsten Arc Welding (GTAW) with low frequency vibrating
filler wire has been used to deposit a metallic alloy. Different trials of weld-on-bead experiments were performed
to obtain the desired envelop of the melt pool shape for build parts with low manufacturing costs and low build
times.",,,,,,
"['Kandukuri, Shruthika', 'Kashyap, Atharva', 'Lipton, Jeffrey']",2023-02-17T14:32:44Z,2023-02-17T14:32:44Z,2022,Mechanical Engineering,,"['https://hdl.handle.net/2152/117483', 'http://dx.doi.org/10.26153/tsw/44364']",eng,2022 International Solid Freeform Fabrication Symposium,Open,sander grips,Vibration Reduction Using Material Jetted Parts for Sander Grips,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3def33ee-5787-44d0-90eb-c9cfb0241c72/download,,"Workers in many industries are exposed to harmful vibrations that negatively impact their 
comfort and long-term health through tools such as hand-held sanders. Here we show that using 
material jetting we can produce durable and effective vibration protection equipment that reduces 
vibrations felt by the user by an average of 23% to 45%. We developed 3D printed vibration 
absorbing grips made from a blend of TangoBlack+ and uncured liquid. The grips were deployed 
at a Boeing factory and survived 1 month of usage. The grips were best at absorbing higher-
frequency vibrations, able to reduce frequencies above 1kHz by over 20dB. Our results 
demonstrate promising capabilities of material jetting viscoelastic materials for direct part 
production of ergonomic components. Moreover, these grips could be improved and used to 
dampen vibrations on other tools such as bucking bars and used in various other industries.",,,,,,
"['Greeley, Andrew', 'Cormier, Denis']",2021-12-07T18:26:45Z,2021-12-07T18:26:45Z,2021,Mechanical Engineering,,"['https://hdl.handle.net/2152/90749', 'http://dx.doi.org/10.26153/tsw/17668']",eng,2021 International Solid Freeform Fabrication Symposium,Open,"['directed energy deposition', 'capture effiiciency']",Vibration-Actuated Powder Dispensing for Directed Energy Deposition Systems,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3973d8e1-2bb5-40ab-96f9-6c37d54fafa6/download,University of Texas at Austin,"Users of powder-fed directed energy deposition system often face several challenges
associated with conventional powder delivery sub-systems. In addition to the high cost of wasted
powder, it can be difficult to plan for the amount of material being deposited when some of the
dispensed powder is not captured in the melt pool. This work studies the effectiveness of a
vibration-actuated powder dispensing system using a nozzle with a small capillary opening. The
opening is sized so that particle contact forces arrest powder flow when the vibration actuator is
turned off. The relative effects of vibration frequency, vibration acceleration, nozzle size and
nozzle inclination are compared with the goal of having the output mass flow rate monotonically
change with one of these parameters. For the materials and parameters explored in this study,
nozzle inclination is found to have the largest effect on mass flow rate output and has the desired
monotonically changing relationship.",,,,,,
"Spencer, John D.",2018-05-03T16:27:48Z,2018-05-03T16:27:48Z,1993,Mechanical Engineering,doi:10.15781/T2DJ5906T,http://hdl.handle.net/2152/65034,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['rapid prototyping', 'Department of Manufacturing Engineering and Operations Management', 'stereolithography']",Vibratory Finishing of Stereolithography Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/dfee2f29-d292-4447-a6c4-e20488c13e34/download,,"Rapid Prototype polymer resin models produced by Stereolithography have, by the
nature of the process, a relatively poor surface roughness, particularly on concave and
convex surfaces. In many cases this is unacceptable, and slow and tedious manual finishing
techniques are often used to improve the surface.
An investigation has been conducted into a range of automated finishing techniques
with the aim of producing an acceptable surface roughness. This paper presents the results
from two techniques, Vibratory Bowl Abrasion and Ultrasonic Abrasion using components
made from Ciba-Geigy XB5081-1 and XB 5143 resins.
Initial results from Scanning Electron Microscopy and surface topography analyses
suggest that both techniques are capable of improving the model surfaces.",,,,,,
"['Melvin III, Lawrence S.', 'Das, Suman', 'Beaman Jr., Joseph Jr.']",2018-09-26T19:21:21Z,2018-09-26T19:21:21Z,1994,Mechanical Engineering,doi:10.15781/T29P2WR3K,http://hdl.handle.net/2152/68587,eng,1994 International Solid Freeform Fabrication Symposium,Open,"['Video microscopy', 'selective laser sintering', 'Optical mangification']",Video Microscopy of Selective Laser Sintering,Conference paper,https://repositories.lib.utexas.edu//bitstreams/a08b6c48-8c45-427f-9980-7b75a59cef14/download,,"This paper presents the design and implementation
of a video microscopy system that enables real time observation
and archival of selective laser sintering of polymer
and metal materials. The design objectives and selection of
system components are discussed in the first section of this
paper. Experimental results from preliminary experiments
conducted on polycarbonate, wax and nylon powders are
also presented.",,,,,,
"['Choi, S.H.', 'Cai, Y.']",2021-09-30T14:28:13Z,2021-09-30T14:28:13Z,9/23/10,Mechanical Engineering,,"['https://hdl.handle.net/2152/88256', 'http://dx.doi.org/10.26153/tsw/15197']",eng,2010 International Solid Freeform Fabrication Symposium,Open,"['dual-level reconfigurable additive manufacturing system (DRAMS)', 'digital fabrication', 'process performance', 'system configurations']",A Virtual Dual-Level Reconfigurable Additive Manufacturing System for Digital Object Fabrication,Conference paper,https://repositories.lib.utexas.edu//bitstreams/76e437a4-2f3a-42aa-a560-b6092ba7089b/download,University of Texas at Austin,"This paper proposes a virtual dual-level reconfigurable additive manufacturing system
(DRAMS) for simulation and verification of deposition strategies in digital fabrication of product
prototypes. The DRAMS is aimed to improve additive manufacturing (AM) processes with the
concept of system reconfiguration. It consists of adaptable support and manipulation modules for
deposition of fabrication materials. Topologies are investigated to determine the structures of
these modules, and methods are developed to evaluate and optimize the system configuration.
Simulations show that the DRAMS can not only handle prototypes of different sizes and
fabrication materials, but also increase the process speed. The DRAMS offers an effective tool
for simulation, verification and optimization of deposition strategies under different system
configurations to improve process performance.",,,,,,
"['Gibson, I.', 'Cobb, S.', 'Eastgate, R.']",2018-05-03T17:45:45Z,2018-05-03T17:45:45Z,1993,Mechanical Engineering,doi:10.15781/T2QV3CM8T,http://hdl.handle.net/2152/65047,eng,1993 International Solid Freeform Fabrication Symposium,Open,"['Department of Manufacturing Engineering and Operations Management', 'Virtual Reality', '3D CAD systems', 'rapid prototyping']",Virtual Reality and Rapid Prototyping: Conflicting or Complimentary?,Conference paper,https://repositories.lib.utexas.edu//bitstreams/7bb68886-65fd-4650-9fa5-135001b04a85/download,,"It is likely that the uses for virtual reality (VR) will coincide with applications that
rapid prototyping systems have already been used for. VR, with the ability to model real
life environments, presents an ideal base for the design and development of new
manufactured products. As a method of producing physical models directly from 3D CAD
systems, rapid prototyping technology has also been used to visualise new product designs.
This paper attempts to determine whether the two technologies are a means to the same
end or whether they combine to form a more efficient route to product development.",,,,,,
"['Qiu, Dan', 'Langrana, Noshir A.', 'Danforth, Stephen C.', 'Safar, Ahmad', 'Jafar, Mohsen']",2019-03-01T17:29:27Z,2019-03-01T17:29:27Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73514', 'http://dx.doi.org/10.26153/tsw/664']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['CAD', 'LM']",Virtual Simulation for Multi-material LM Process,Conference paper,https://repositories.lib.utexas.edu//bitstreams/55891e1e-3100-43f6-8b5b-aadd87201b29/download,,"In an ONR funded MURI program, to improve quality of multi-material parts,
we've been developing an advanced computer simulation for the multi-material layered
manufacturing (LM) process. The CAD models and their .stLfiles are created using. the
commercially available software such as I-DEAS and ProE. Using this information, one
tool path file per material is generated. Our file preparation algorithm, systematically,
layer by layer, integrates all tool path files into one multi-material tool path file. The
results of the multi-material tool path are graphically visualized using the simulation
algorithm (written in c++ & SGI OpenGL). From a virtual simulation, we can check the
LM process, and make the best selection of tool path parameters afterwards. After several
trials from design to simulation, if the simulation result is acceptable, the real
manufacturing can be started. And the part's quality should be better than a part
manufactured without running simulation in advance. This paper will represent .•. new
studies on using real toadshapes to get more realistic simulation results. Many parts have
been successfully simulated using our method.",,,,,,
"['Duty, Chad', 'Ajinjeru, Christine', 'Kishore, Vidya', 'Compton, Brett', 'Hmeidat, Nadim', 'Chen, Xun', 'Liu, Peng', 'Hassen, Ahmed Arabi', 'Lindahl, John', 'Kunc, Vlastimil']",2021-11-02T18:14:11Z,2021-11-02T18:14:11Z,2017,Mechanical Engineering,,https://hdl.handle.net/2152/89854,eng,2017 International Solid Freeform Fabrication Symposium,Open,"['viscoelastic model', 'print conditions', 'printability', 'extrusion-based printing']",A Viscoelastic Model for Evaluation Extrusion-Based Print Conditions,Conference paper,https://repositories.lib.utexas.edu//bitstreams/4e02ec81-20bd-4584-856c-cefafbb69910/download,University of Texas at Austin,"Extrusion-based printing systems have improved significantly over the past several years,
allowing for higher throughput, higher temperatures, and larger components. At the same time,
advanced materials are being introduced on the market that can provide improved performance
over a range of operating conditions. Often these materials incorporate fiber reinforcements,
reactive resins, and additives to control reaction kinetics, flow rheology, or thermal stability. This
study presents a general framework for evaluating the printability of various candidate materials
based on a basic viscoelastic model. The model addresses fundamental requirements for extrusion-based printing, including pressure-driven flow, bead formation, bead functionality, and
component-level functionality. The effectiveness of this model for evaluating the impact of
compositional variations and identifying appropriate processing conditions has been demonstrated
for specific materials on direct write, fused filament fabrication, and large-scale extrusion
platforms.",,,,,,
"['Vaish, Apoorv', 'Yang Lee, Shien', 'Valdivia Alvarado, Pablo']",2021-11-09T15:38:53Z,2021-11-09T15:38:53Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90098', 'http://dx.doi.org/10.26153/tsw/17019']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['viscosity control', 'pseudoplastic polymers', 'embedded 3D-printing', 'direct ink writing']",Viscosity Control of Pseudoplastic Polymer Mixtures for Applications in Additive-Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/75c321e5-6461-4dec-9ded-11fc6f235dda/download,University of Texas at Austin,"Various additive manufacturing (AM) processes exploit the rheological properties of non-Newtonian (e.g. pseudoplastic) polymers for stability and feature realization. For embedded
3D-printing (e3DP) and direct ink writing (DIW), features are deposited on top or within a layer
of matrix/base material and the rheological properties of the matrix are crucial for satisfactory
prints. Due to their high apparent viscosities under static conditions, these base polymers do not
flow easily when poured in bulk into the fabrication space. Traditionally, manual methods were
employed to spread them into an even layer. In this study, an alternative approach to spread and
level pseudoplastic polymers using oscillatory shear stresses generated by a vibrating actuator
is presented. The proposed approach lowers the viscosity of the polymers, thereby facilitating
gravity-driven flow to generate a flat polymer-air interface. A fluid rheology model detailing
the parameters influencing the process is presented and experiments are performed using these
parameters.",,,,,,
"['Karnati, Sreekar', 'Matta, Niroop', 'Sparks, Todd', 'Liou, Frank']",2021-10-07T15:33:00Z,2021-10-07T15:33:00Z,2013,Mechanical Engineering,,"['https://hdl.handle.net/2152/88482', 'http://dx.doi.org/10.26153/tsw/15416']",eng,2013 International Solid Freeform Fabrication Symposium,Open,"['laser metal deposition', 'process monitoring', 'thermal camera']",Vision-based Process Monitoring for Laser Metal Deposition Processes,Conference paper,https://repositories.lib.utexas.edu//bitstreams/0489e5e2-3441-4eda-9170-8c62cd4b05bb/download,University of Texas at Austin,"Laser Metal deposition is a process with immense scope and promise for becoming a
robust manufacturing technology in the near future. Monitoring process variables is very
instrumental in process planning and output monitoring. The current work deals with realizing
the effect of power modulation on size of the high temperature region during deposition with
varying powder feed. A thermal camera was used to visualize and analyze the deposition
process. The area of the high temperature region through the deposition was identified and
compared to realize the effect of each variable parameter during deposition. The power
modulation was fruitful in modulating the area of the high temperature zone. Optimum set of
parameters to perform deposition were identified.",,,,,,
"['Adediran, A.I.', 'Nycz, A.', 'Thornton, A.', 'Love, L.J.']",2021-11-04T18:52:19Z,2021-11-04T18:52:19Z,2017,Mechanical Engineering,,"['https://hdl.handle.net/2152/90003', 'http://dx.doi.org/10.26153/16924']",eng,2017 International Solid Freeform Fabrication Symposium,Open,"['laser metal wire deposition', 'LMD-w', 'image processing', 'visual sensing', 'discontinuities', 'error detection']",Visual Sensing and Image Processing for Error Detection in Laser Metal Wire Deposition,Conference paper,https://repositories.lib.utexas.edu//bitstreams/76be9105-9e5c-41f7-8440-340220e95ba3/download,University of Texas at Austin,"Laser metal deposition with wire (LMD-w) involves feeding metal wire through a nozzle
and melting the wire with a high-power laser. With efficient process control, i.e. sensing,
processing, and feedback correction of errors, the technology has the potential to change the
course of manufacturing. However, the limitation most often encountered in LMD is the
difficulty in controlling the process. Monitoring and control of metal additive manufacturing
processes has been mostly researched on powder-based systems and has not been extensively
investigated on metal wire feed systems. This work proposes a method for detecting
discontinuities in a deposited layer in the LMD-w process via optical inspection and processing
of images obtained from a high-resolution camera. The aim is to develop an effective sensing
module that automatically detects irregularities in each layer before proceeding to subsequent
layers, which will reduce part porosity and improve inter-layer bond integrity.",,,,,,
"['Kattethota, Gautham', 'Henderson, Mark']",2019-02-22T19:53:22Z,2019-02-22T19:53:22Z,1998,Mechanical Engineering,,"['https://hdl.handle.net/2152/73466', 'http://dx.doi.org/10.26153/tsw/616']",eng,1998 International Solid Freeform Fabrication Symposium,Open,"['FDM', 'Rapid Prototyping']",A Visual Tool to Improve Layered Manufacturing Part Quality,Conference paper,https://repositories.lib.utexas.edu//bitstreams/19159cc2-889f-40de-83c0-726c36372b32/download,,"A software tool is described that will aid the user in. choosing the optimum build orientation
to obtain the ..best composite set of surface finishes on a part built .on a Fused Deposition
Modeling (FDM) rapid prototyping machine.• Experiments were conducted to obtain statistical
.surface roughness values as a function of orientation and layer thickness.Three types of surfaces
(features}.have been. considered planar (both upward facing and downward facing (over hang
surfaces)),.quadratic and free form Surfaces..Data analysis of surface roughness of planar surfaces at
various orientations·and their mapping. to. quadratic and freeform surfaces are presented.
decision support software tool allows dynamic .. color-coded visualization of the surface quality
simultaneous with build parameters including orientation and layer thickness.",,,,,,
"['Choi, S.H.', 'Chan, A.M.M.']",2019-10-24T18:06:24Z,2019-10-24T18:06:24Z,2002,Mechanical Engineering,,"['https://hdl.handle.net/2152/77413', 'http://dx.doi.org/10.26153/tsw/4502']",eng,2002 International Solid Freeform Fabrication Symposium,Open,Prototyping,Visualization of Surface Accuracy for Virtual Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/da94f71c-e098-49a4-95df-8dae12baadd3/download,,"This paper introduces a virtual prototyping (VP) system that simulates a RP
process to produce a virtual prototype of a product, which facilitates visual study of
the surface quality of the physical prototype that the RP machine will subsequently
fabricate. The virtual prototype displayed in a computerized virtual environment
allows the designer to analyze the surface texture and accuracy of a product prototype
conveniently. It may be super-imposed on its original design so that all dimensional
deviations are clearly highlighted. The system can further pinpoint the areas in which
the dimensional deviations are out of the acceptable range. The designer can hence
improve the accuracy of the prototype well before physical fabrication by optimizing
the RP fabrication parameters, such as the layer thickness, hatch space and build
orientation, in the system. In this paper, the simulation principles will be described
and case studies will be given to illustrate how the system works.","The authors would like to acknowledge the Research Grant Council of the Hong
Kong SAR Government and the CRCG of the University of Hong Kong for their
financial support for this project.",,,,,
"['Campbell, R. Ian', 'Jee, Haeseong J.', 'Lee, H.S.']",2019-09-23T16:56:43Z,2019-09-23T16:56:43Z,2000,Mechanical Engineering,,"['https://hdl.handle.net/2152/75970', 'http://dx.doi.org/10.26153/tsw/3069']",eng,2000 International Solid Freeform Fabrication Symposium,Open,Visualization,Visualization Tools for Design Support in SFF 437,Conference paper,https://repositories.lib.utexas.edu//bitstreams/213867fa-8816-4191-8c2b-4b9719851778/download,,"When considering the use of SFF, there are many questions a designer might ask. What model orientation should be used, will the model have adequate aesthetic and functional properties, is the STL file suitable for transfer to the SFF machine? These questions could be answered by a comprehensive design support system for SFF. This paper addresses a number of components for such a system that can be met through the use of visualization tools. These include: 1. Visualization of surface roughness 2. Visualization of characteristic features (e.g. surface macro-texture) 3. Visual simulation of fabrication Example applications of these tools are presented together with a status review of their implementation to date. It is envisaged that these tools will be incorporated into an already existing network-based preprocessor used for visualization, repair and slicing of STL files. The direction of future work is also discussed which will include the visual representation of functionally graded materials (connected with FEM results).",,,,,,
"['Pegues, Jonathan', 'Roach, Michael', 'Williamson, R. Scott', 'Shamsaei, Nima']",2021-11-11T15:08:09Z,2021-11-11T15:08:09Z,2018,Mechanical Engineering,,"['https://hdl.handle.net/2152/90213', 'http://dx.doi.org/10.26153/tsw/17134']",eng,2018 International Solid Freeform Fabrication Symposium,Open,"['additive manufacturing', 'fatigue behavior', 'defects', 'fractography']",Volume Effects on the Fatigue Behavior of Additively Manufactured Ti-6Al-4V Parts,Conference paper,https://repositories.lib.utexas.edu//bitstreams/df161b01-b19f-415f-80e0-b01fc1e03ddf/download,University of Texas at Austin,"Recent interest to implement additive manufactured parts into structural applications has created
a critical need to better understand the fatigue behavior of these parts. Alloys such as Ti-6Al-4V
are popular in the aerospace and biomedical industries due to their superior strength to weight ratio
and biocompatibility. In these two industries, part sizes can range from very small surgical
implants to large structural components, all of which are subjected to cyclic loading conditions.
The fatigue behavior of additively manufactured parts may show more sensitivity to part size than
their wrought counterparts due to the defects that are inherent to the fabrication process. This
research investigates the sensitivity of additively manufactured Ti-6Al-4V parts to volume size by
comparing the stress-life fatigue curves of three geometries with increasing gage volumes. Results
indicate that additive Ti-6Al-4V parts show reduced fatigue lives because of an increase in surface
or near-surface defects.",,,,,,
"['Ma, Di', 'Lin, Feng', 'Chua, Chee Kai']",2019-03-08T17:50:40Z,2019-03-08T17:50:40Z,1999,Mechanical Engineering,,"['https://hdl.handle.net/2152/73574', 'http://dx.doi.org/10.26153/tsw/716']",eng,1999 International Solid Freeform Fabrication Symposium,Open,"['Rapid prototyping', 'Solid Freeform Fabrication']",Volume Modeling for Rapid Prototyping,Conference paper,https://repositories.lib.utexas.edu//bitstreams/ea247511-1425-41e7-abfd-b77b4fc20247/download,,"The expanding workspace of Rapid Prototyping will draw on the new developments
in geometric modeling. Volume modeling has substantial advantages over other modeling
schemes to meet the emerging requirements of Rapid Prototyping technology. It provides us with
a new approach to design complex geometry and topology. The integration of the volume
modeling and Rapid Prototyping technology will help us to fully exploit RP's ability to fabricate
objects with complex structures. This paper addresses our research and practice in a volume
modeling system toward Rapid Prototyping. Novel techniques in volumetric data manipulation,
NURBS volume models and triangular facet generation over solid models are presented.
Computer models designed by this system and their corresponding DTM products are also
shown atthe end of this paper.",,,,,,
"['Yim, Soonkyu', 'Gea, Hae Chang']",2019-10-18T16:04:01Z,2019-10-18T16:04:01Z,2001,Mechanical Engineering,,"['https://hdl.handle.net/2152/76246', 'http://dx.doi.org/10.26153/tsw/3335']",eng,2001 International Solid Freeform Fabrication Symposium,Open,Voxel-based,Voxel-based Modeling with Multi-resolution Wavelet Transform for Layered Manufacturing,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3857a0d5-4939-429c-8623-a8a36be079ef/download,,"A voxel-based modeling system with multi-resolution for layered manufacturing is presented in
this paper. When dealing with discretized data input, voxel-based modeling shows its clear
advantages over the conventional geometric modeling methods. To increase the efficiency of
voxel data due to its large storage space requirement, multi-resolution method with wavelet
transform technique is implemented. Combining with iso-surface generation and lossless
polygon reduction, this voxel-based modeling method can easily work with layered
manufacturing. To demonstrate these concepts, components with different resolutions are built
using Layered Manufacturing and presented in the paper.",,,,,,
"['Ye, Jennings Z.', 'Sun, Yaxuan', 'Taylor, Hayden']",2024-03-26T20:25:16Z,2024-03-26T20:25:16Z,2023,Mechanical Engineering,,"['https://hdl.handle.net/2152/124395', 'https://doi.org/10.26153/tsw/51003']",en_US,2023 International Solid Freeform Fabrication Symposium,Open,"['computed axial lithography', 'surface quality', 'radon transform', 'voxel']",VOXEL-FREE RADON TRANSFORM FOR IMPROVING SURFACE QUALITY IN COMPUTED AXIAL LITHOGRAPHY,Conference paper,https://repositories.lib.utexas.edu//bitstreams/3a293a2d-ac07-44e7-bd65-c904362eca48/download,University of Texas at Austin,"Computed axial lithography (CAL) is an additive manufacturing process that projects light
patterns onto a rotating vial of photosensitive resin to print the desired object through the
superposition of light energy. Currently, these projection patterns are generated by voxelizing a
target object from an STL or another 3D file format and applying the Radon transform through an
iterative optimization process. In this work, a voxel-free method to generate projection sets is
proposed. Here, the Radon transform is performed directly on a non-voxelized target object by
calculating intersections between incident rays of light and triangles of the original STL surface
mesh. Initial simulated results show a more consistent light dose at the surface of the object,
indicating improved surface quality and smoothness. Additionally, simulations show a more
uniform object interior using the proposed method as well as the potential for improved speed
scaling with object size.",,,,,,