bluuebunny/crossref_metadata_2025 huggingface dataset:
Historic Retrospection and Present Status of Severe Plastic Deformation in China
Authors: Wang Jing Tao
Published: March 2009

Severe plastic deformation (SPD) in solid metals, with an aim to obtaining ultra-fine grained or even nano-structured materials, attracted great efforts all over the world. This article retrospects to the ancient origin of this technique and presents some aspects of recent research activities in China briefly. SPD appeared as “folding and forging” for the fabrication of high quality steel sword as early as ~ BC500, this technique developed and maturated at around AD220~280, with a special term in Chinese “BAI-LIAN” (means Multitudinous Repetitive Processing), the steel fabricated by this process is called BAI-LIAN steel. Inlay gold characters on unearthed ancient steel swords recorded the number of processing repetitions. This ancient technique even resulted in several Chinese idioms very popular until at present time. Current research activities on SPD in China, supported by the National Science Foundation, National high tech program, local government technical programs and enterprises etc., are blooming all over China, in Universities, Chinese Academy of Science, National Research Institute and Enterprises. SPD is becoming a hotspot in materials field in China. Chinese materials scientists expect greatly increasing contribution to the development of SPD.
3D-Atom Probe Investigation of Vacancy Induced Interdiffusion during High Pressure Torsion Deformation
Authors: Sauvage Xavier
Published: March 2009

Concentration gradients resulting from long range diffusion during Severe Plastic Deformation (SPD) have been investigated with the 3D Atom Probe technique (3D-AP). First, in a pearlitic steel where alloying elements (Mn, Si and Cr) are partitioned between the ferrite and carbides in the non-deformed state. After processing by High Pressure Torsion (HPT), they are homogeneously distributed in the nanostructure, indicating that long range diffusion occurred along with the dissolution of carbides. 3D-AP data of a Cu-Fe composite processed by HPT show as well a significant interdiffusion of Cu and Fe, probably promoted by additional vacancies. On the basis of these experimental data, and using the theory described for irradiated materials, vacancy fluxes and vacancy production rates were estimated assuming that new vacancies are continuously produced and eliminated on grain boundaries.
A New Deformation Mechanism in Nanoscale Fe-C Composite as a Result of a Stress-Induced α→γ Transformation
Authors: Ivanisenko Julia , MacLaren Ian , Valiev Ruslan , Fecht Hans Jorg
Published: March 2009

Recent studies of nanocrystalline materials have often found that the deformation mechanisms are radically different to those in coarse-grained materials, resulting in quite different mechanical properties for such materials. The use of pearlitic steels for the study of the deformation mechanisms in bcc materials with ultrafine grain sizes is quite convenient, because it is relatively straightforward to obtain a homogenous nanocrystalline structure with a mean grain size as small as 10 nm using various modes of severe plastic deformation (SPD). In this paper we show that highpressure torsion of an initially pearlitic steel results in a nanostructured steel in which austenite has been formed at or close to room temperature. The orientation relationship between neighboring ferrite and austenite grains is the well-known Kurdjumov-Sachs orientation relationship, i.e. the same observed in temperature-induced martensitic transformation of iron and steels. It is shown that this must have resulted from a reverse martensitic transformation promoted by the high shear strains experienced by the material during severe plastic deformation of the nanocrystalline structure. This transformation represents an alternative deformation mechanism that can be activated when conventional deformation mechanisms such as slip of lattice dislocations become exhausted.
ECAP Processed Copper during Deformation and Subsequent Annealing
Authors: Molodova Xenia , Bhaumik Sheila , Winning Myrjam , Gottstein Günter
Published: March 2009

Microstructure and texture evolution of pure copper (99.95%) after Equal-Channel Angular Pressing (ECAP) and subsequent heat treatment were investigated. Initially the material was subjected up to twelve passes with a 90° die angle using route Bc. This resulted in an equivalent strain of 13.8. After deformation the samples were annealed at different temperatures. The deformed and annealed states were characterized by using the crystallographic texture analysis, EBSD measurements and microhardness tests.
Microstructure Evolution and Aging Kinetics of Al-Mg-Si and Al-Mg-Si-Sc Alloys Processed by ECAP
Authors: Angella Giuliano , Bassani Paola , Tuissi Ausonio , Ripamonti D. , Vedani Maurizio
Published: March 2009

A study was carried out on a ECAP processed Sc-containing Al-Mg-Si alloy and on a reference 6082 alloy to investigated grain structure evolution during severe plastic deformation and post-ECAP aging behaviour. The results showed that the mechanism of ultrafine structure development was substantially unchanged with respect to a reference Sc-free alloy. Also the aging sequence and precipitation kinetics of the two alloys revealed to be comparable. The ECAP processed samples of the 6082 reference alloy showed a clear recrystallization peak at temperatures in the range 315-360°C, depending on the amount of strain experienced, whereas the Sc-containing alloy retained its ultrafine structure up to temperatures well exceeding 450°C, under the conditions reproduced in a DSC temperature scan.
Development of Complex Methods, Combining Thermal Treatment with Severe Plastic Deformation, for Processing of High-Strength Nanostructured Cu-1%Cr-0.7%Al Alloy
Authors: Alexandrov Igor V. , Latysh V.V. , Hong Sun Ig , Faizova S.N. , Polovnikov V.M.
Published: March 2009

The current work presents new results of investigation of properties and structure of nanocrystalline and submicrocrystalline Cu-1%Cr-0.7%Al alloy. Two severe plastic deformation (SPD) techniques were applied to refine the structure: high pressure torsion and equal-channel angular pressing (ECAP). The first technique was applied to conduct preliminary studies of the alloy different thermal treatments as before SPD as well as after it. A new technological thermomechanical technique for processing of bulk billets of Cu-1%Cr-0.7%Al alloy possessing an ultrafine grained structure was developed on the basis of the obtained results. This technique comprises a combination of ECAP and other deformational processes with the thermal treatment. High values of the tensile strength and yield stress - 700 MPa and 16% accordingly – have been obtained as a result of such treatment, whereas these values after conventional treatment consisted 450 MPa and 20% respectively.
Hardening Viscous Failure and Strain Localization during Severe Plastic Deformation
Authors: Beygelzimer Yan , Prokof'eva O. , Efros B. , Varyukhin Viktor
Published: March 2009

The analysis is made of effect and physical mechanisms of the influence of pressure on metal materials that are in the state of plastic flow, as well as on characteristics of materials undergone severe plastic deformation under pressure.
Single Roll Drive Equal Channel Angular Process –a Potential Severe Plastic Deformation (SPD) Process for Industrial Application
Authors: Chen Bin , Lin Dong Liang , Zeng Xiao Qin , Lu Chen
Published: March 2009

Single roll drive equal channel angular process (SRD-ECAP) is derived from classical equal channel angular pressing (ECAP). It overcomes the drawbacks of ECAP, which is a discontinuous process and can only process short billets with invariable square or round section. SRD-ECAP, however, can process long billets continuously. In addition, it can also process sheet or strip. Another merit is that diameter or thickness of billets processed is adjustable. The structure of SRD-ECAP is quite simple and easy to be realized. In this paper, stress analysis has also been carried out. It is believed that SRD-ECAP can be a potential severe plastic deformation (SPD) process for Industrial Application.
Increasing the Mechanical Properties of FCC- and BCC-Metals by Combined Cold Severe Plastic Deformation
Authors: Varyukhin Viktor , Pashinskaya E.G. , Tkachenko V.M. , Bilousov M.M.
Published: March 2009

It is shown that the twist hydroextrusion results in the formation of fine crystalline structure with grains of elliptical shape oriented at an angle of ≈450 to the axis of deformation. Mechanical properties of the processed copper are characterized by a high level of strength and plasticity characteristics. Peculiarities of the formed structure are inherited under the subsequent rolling, they are in untypical location of grains relative to the axis of deformation.
Effect of Rolling Direction on the Microstructure and Mechanical Properties of Accumulative Roll Bonding (ARB) Processed Commercially Pure 1050 Aluminum Alloy
Authors: Kim Yong Suk , Kang Suk Ha , Shin Dong Hyuk
Published: March 2009

The cross-ARB (C-ARB) process, which adopts cross rolling of the two stacked plates, has been performed up to seven cycles on a commercial purity 1050 aluminum alloy to obtain ultrafine grains with an average grain size of 0.7μm. Microstructural evolution of the C-ARB processed aluminum alloy was examined by a transmission electron microscopy as a function of process cycle number (accumulated plastic strain). Tensile property of the severely deformed Al alloy was also explored. Grain size of grains of the C-ARB processed alloy varied across thickness of the rolled plate. The size of grains at the top and bottom of the rolled plate converged to 0.65μm, while that of grains at the center of the plate increased with the number of ARB cycles. Tensile strength of the CARB processed 1050 Al alloy increased from 100MPa (as-received) to 160MPa. Tensile elongation varied with the number of cycles, but 15% of failure strain was measured from the 6-cycle C-ARB processed specimen. The variation of the elongation with the cycle number coincided exactly with the variation of grain size at the center of the processed plate.
Consolidation of Amorphous Al86Ni6Co2Gd6 Melt-Spun Ribbons by Twist Extrusion
Authors: Varyukhin Viktor , Tkatch V.I. , Maslov V.V. , Beygelzimer Yan , Synkov Sergey , Nosenko V.K. , Rassolov S.G. , Synkov Alexandr , Krysov V.I. , Mashira V.A.
Published: March 2009

Amorphous Al86Ni6Co2Gd6 ribbons produced by melt-spinning processing were consolidated using twist extrusion (TE). Electrical resistance measurements showed that under continuous heating at 5 K/min crystallization begins at 473 K by formation of Al-nanocrystals and ends at 673 K by formation of equilibrium intermetallics. From one to five TE extrusion passes were conducted in several experiments at temperatures 458-573 K and applied pressures ranged between 1150-1700 MPa. The fully dense billets with dimensions 14×23×40 mm3 were produced at extrusion temperatures ≥ 523 K. The maximum microhardness (550 kgf/mm2) was reached for the bulk materials consolidated at 523 K with a nanocomposite structure consisted of Al-nanocrystals with size about 13 nm embedded in amorphous matrix. The billet compacted at 573 K has a fully crystallized structure and lower microhardness (380 kgf/mm2).
Microstructural Change of Beta Type Titanium Alloy by Intense Plastic Deformation
Authors: Itoh Goroh , Hasegawa Hisashi , Zhou Tsing , Motohashi Yoshinobu , Niinomi Mitsuo
Published: March 2009

Usual static recrystallization treatment and a method to provide intense plastic deformation, ARB namely Accumulative Roll-Bonding, have been applied to two beta type titanium alloys, i.e. Ti-29Nb-13Ta-4.6Zr and Ti-15V-3Cr-3Sn-3Al. Microstructural change as well as work-hardening behavior was examined as a function of plastic strain. Both the work-hardening rate and the hardness at the initial as-hot-rolled state were smaller in the Ti-Nb-Ta-Zr alloy than in the Ti-V-Cr-Sn-Al alloy. Recrystallized grains of 14μm in size were obtained by the usual static recrystallization treatment, which was significantly smaller than that of the starting as-hot-rolled plate of 38μm. No significant change other than flattening and elongating of the original grains was found in the optical microscopic scale. It was revealed, however, from a TEM observation combined with selected area diffraction technique that geometric dynamic recrystallization occurred in the Ti-Nb-Ta-Zr alloy deformed at room temperature by a true strain of 5, resulting in an ultra-fine-grained microstructure where the grain size was roughly estimated to be about 100nm.
Processing of Ultrafine-Grained Cu-Fe-Cr Composite by Equal Channel Angular Pressing
Authors: Joo K.H. , Chang K.I. , Kim Hyoung Seop , Hong Sun Ig
Published: March 2009

In this study, equal channel angular pressing was carried out on Cu-Fe-Cr composites at room temperature. The microstructure and hardness of Cu-Fe-Cr pressed using different ECAP routes were investigated. All Cu-Fe-Cr specimens showed ultrafine-grained microstructures with the shape and distribution of Fe-Cr phase dependent on the processing routes. As the number of pressing increased by route A, the initial denfrite of Fe-Cr phase were elongated along the shear direction and developed into filaments. On the other hand, as the number of pressing increased by route Bc, the initial dendrite became finer by fragmentation with no pronounced change of the shape. In route C, the shearing of the second phase in the first pass can be reversed by the shearing in the reverse direction in the second pass and the morphological change of Fe-cr particles is minimal. The hardness increased more rapidly in route Bc and route C than in route A. In ECAPed Cu-Fe-Cr, the spacing between Fe-Cr filaments did not decrease appreciably with strain unlike the cold-drawn Cu-Fe-Cr in which the spacing between Fe-Cr filaments decreases rapidly with strain. The higher strength in route C can be associated with the sub-divided microstructure resulting from the activation of various slip systems enhanced by the presence of larger strong particles. This result suggests that the microstructural development in Cu matrix is more important in strengthening than the morphological development of Fe-Cr phase in ECAPed Cu-Fe-Cr.
Mechanical Properties and Microstructure of Mg-Zn-Y Alloys Processed by ECAE
Authors: Yoshimoto Shintaro , Miyahara Yuichi , Horita Z. , Kawamura Yoshihito
Published: March 2009

Development of high strength I/M Mg alloys has been tried by ECAE processing. The mechanical properties and microstructure of ECAE-processed Mg97Zn1Y2 alloy with LPSO (long-periodic stacking ordered) structure were investigated. The tensile yield strength and elongation of as-cast Mg97Zn1Y2 were improved substantially by ECAE process. ECAE-processed with yield strength of 290 MPa and elongation of 22 % was obtained. The microstructure of ECAE-processed Mg97Zn1Y2 alloy consisted of refined α-Mg with the grain size around 6.5 μm and finely dispersed LPSO phase. Furthermore, the some texture was formed by ECAE process. The improved mechanical properties seem to be originated by the microstructure refinement and texture.
Gradient Structure Formation by Severe Plastic Deformation
Authors: Danylenko M. , Gorban Victor F. , Podrezov Yu.N. , Firstov Sergiy A. , Rosenberg O. , Shejkin S. , Morito F. , Yamabe-Mitarai Yoko
Published: March 2009

Severe plastic deformation (SPD) techniques are the best for producing of massive nanostructured materials. The methods of equal channel angular pressure (ECAP) and twist extrusion (TE) are realized by simple shear uniform deformation without change of cross-section sizes of sample.
In the case of roll forming (RF) the shear strain is localized in the near-surface layer of metal. Intensity of shear strain in the near-surface layer depends on variation of parameters of deformation and conditions of friction in a contact.
Steel 65G (0.65C, 0.3Si, 0.6Mn, 0.3Cr, and 0.3Ni) was deformed by roll forming. Transmission electron microscopy (TEM) of “cross-section” samples was used for studying of gradient structure of deformed material. TEM investigation shown that cell substructure in a near-surface layer have been formed. The depth of deformed layer is approximately 40 micrometers. Average cell size in cross-section direction is about 100 - 200 nm. Thin nanostructure layer with cell size about 20-30 nm was detected. In our opinion such substructure formed due to effect of “good” impurities.
Corrosion and Mechanical Behaviors of Cu-35%Zn Alloy Prepared by Equal Channel Angular Pressing (ECAP)
Authors: Choi Y. , Cho Nam Ihn , Kim Hyoung Seop , Hong Sun Ig
Published: March 2009

Effect of equal-channel angular pressing (ECAP) on the corrosion and mechanical properties of Cu-35%Zn alloy were studied. Two types of feed direction were selected. One is parallel pass and the other is 180°degree rotated ECAP pass after each pass. Both ECAP passes made texture in each specimen in which shear band with 45 degree on transverse direction and twins exist. The specimen prepared by parallel ECAP pass has finer shear band. Relative amount of twins to shear band on the microstructure becomes decrease with number of ECAP pass. Microhardness increased from 75 Hv to 210 Hv by ECAP. The corrosion potential and rate of the ECAPed Cu-35%Zn alloys in aerated aqueous 1 M-H2SO4 solution were –92.3 mVSHE and 3.72x10-2 A/cm2 for route- A and –38.6 mVSHE and 5.08x10-2 A/cm2 for route-C, respectively. The corrosion potential and rate of depended on the feed direction and number of pass.
A Transmission Electron Microscopy Study of the Role of Sc+Zr Addition to a 6082-T8 Alloy Subjected to Equal Channel Angular Pressing
Authors: Cabibbo Marcello , Evangelista E. , Scalabroni C. , Bonetti Ennio
Published: March 2009

The microstructural evolution with strain was investigated either in a Zr-modified 6082 Al-Mg-Si alloy and in the same alloy added with 0.117wt.% Sc, subjected to severe plastic deformations. Materials were deformed by equal-channel angular pressing using route BC, up to a true strain of ∼12. A strain of ~4 produced a sub-micrometer scale microstructure with very fine cells (nanometer scale) in the grain interior. The role of fine dispersoids (Al3(Sc1-x,Zrx)) was investigated by transmission electron microscopy techniques and discussed. Dispersoids were responsible for a more complex dislocation substructure with strain. Compared to the commercial parent alloy, block wall formation and propagation were favored by the presence of Sc-Zr containing dispersoids, while cell boundary evolution was less affected, compared to the commercial parent alloy. Mean misorientation across block walls increased with strain much more in the Sc-Zr containing alloy, reaching a plateau, starting from a true strain of ∼8. Misorientation across cell boundaries continuously increased to ∼8° and ∼5° for the Sc-Zr and Zr containing alloy, respectively.
Formation of Texture and Structure in Rods of Copper and Titanium under Equal-Channel Angular Pressing
Authors: Perlovich Yuriy , Isaenkova Margarita , Fesenko Vladimir , Grekhov M. , Alexandrov Igor V. , Beyerlein Irene J.
Published: March 2009

New data on structure and texture features of Cu and Ti rods, subjected to ECAP at 20oC and 400oC respectively, were obtained by means of advanced X-ray diffractometric methods. A deformation inhomogeneity through rod’s cross-section was studied by reduced cubic samples 3x3x3 mm, cut out from different regions of rods. The inhomogeneity of ECAP rods is characterized by distributions of texture and substructure parameters. Main tendencies in structure formation by ECAP are revealed.
Microstructure and Corrosion Behaviour of Ultrafine-Grained Copper
Authors: Hadzima Branislav , Janeček Miloš , Hellmig Ralph Jörg , Kutnyakova Yulia , Estrin Yuri
Published: March 2009

Microstructure evolution and corrosion behaviour of ultrafine-grained copper processed by equal channel angular pressing (route Bc) were studied. The results of TEM investigation of the microstructure evolution are presented along with the measurements of the corrosion potential, the corrosion current density and the anodic current density for two aggressive media, viz. 3% NaCl and 1M H2SO4. An important finding and a good news is that the corrosion behaviour of ECAP copper is not inferior to and does not qualitatively differ from that of the coarse grained material. Moreover, it was shown by SEM investigation that the corrosion damage is more homogeneous in ultrafine grained ECAP processed copper than in its coarse grained counterpart.
Three Dimensional Numerical Investigation of Equal Channel Multi-Angular Pressing
Authors: Pham Quang , Yoon Seung Chae , Hong Sun Ig , Kim Hyoung Seop
Published: March 2009

Plastic deformation behavior during equal channel multi-angular pressing (ECMAP) was analyzed using the three dimensional finite volume method of the commercial code MSC.Superforge. In order to understand local and global deformation characteristics, effective strain and pressing load histories were investigated. The predicted plastic deformation behavior of the workpiece material during ECMAP of route A, route B and route C with a theoretical total strain of ~2.2 upon a single pass at three different friction factors (m=0, 0.1 and 0.2) was compared. The predicted strain results show different values in outside and similar values in central regions of the processed workpieces with different friction and forming routes. The pressing loads are higher under higher friction condition, showing almost no difference with three different pressing routes.
Structure and Mechanical Properties of Submicrocrystalline Copper Produced by ECAP to Very High Strains
Authors: Vinogradov Alexei , Suzuki T. , Hashimoto Satoshi , Kitagawa Kazuo , Kuznetsov A.A. , Dobatkin Sergey V.
Published: March 2009

The present work is aimed at linking the microstuctutral features obtained after severe plastic deformation via ECAP to the tensile behavior and thermal stability of pure (99.98%) copper processed by routes A and Bc to different number of passes. The main conclusion one can draw unambiguously from the currently available results is that the strain path exerts relatively little effect on the resultant tensile properties when the number of pressing is sufficiently large, although there have been some marked differences in crystallographic textures and distribution of grain-boundaries. The effect of the number of pressings on the tensile ductility is considerable.
Dislocation-Crystal Plasticity Simulation Based on Self-Organization for Repartition of Dislocation Cell Structures and Subgrain
Authors: Yamaki Naoshi , Aoyagi Yoshiteru , Shizawa Kazuyuki
Published: March 2009

A self-organization model for repartition of dislocation cell structures and transition of subgrains on a three-stage hardening of single crystal are developed. Stress-effect coefficients models are proposed in order to introduce stress information into the reaction-diffusion equations. A FD simulation for dislocation patterning and a FE one for crystal deformation are simultaneously carried out for an FCC single crystal. It is numerically predicted that a cell structures are repartitioned and the generated dislocation pattern in stage III can be regarded as a subgrain.
A Novel Parallel Hybrid Motorcycle Transmission
Authors: Sheu Kuen Bao , Hsu Tsung Hua , Hsu Yuan Yong
Published: March 2009

This paper presents a novel parallel hybrid transmission for motorcycles. This
transmission incorporates a mechanical type rubber V-belt continuously variable transmission and chain drives to combine the power of the two power sources, an internal combustion engine and an electric motor. By using the mechanical type clutches used in the proposed transmission, it can provide a parallel hybrid that can be grouped into four modes of operation: electric motor mode, engine mode, engine/charging mode, and power mode. A design example is built and tested.
The Inverse Prediction of the Geometry of a Two Dimensional Plate with a Rectangular Cavity
Authors: Su Chin Ru , Chen Cha'o Kuang
Published: March 2009

The contour of a two dimensional plate with a rectangular cavity was predicted by the
linear least-squares error method. In the analysis process the heat conduction equation and the boundary conditions were discretized to form a linear matrix equation. On the basis of the concept of a virtual area, the unknown contour of the two dimensional plate was converted into virtual boundary temperatures that can be definitely expressed. Under the condition that the solution form and the initial values didn’t need to be preset, the contour of the two dimensional plate was
predicted from temperatures of some points in the plate by only two inverse processes. The results show that even though the positions of the measured points are different the temperature field of the whole virtual system doesn’t change. When the number of the measured points is decreased or the
measurement error is increased, the error of the prediction will increase. With reasonable measurement error, the geometry of the plate can be successfully predicted from a few measured points by the method proposed in this work.
Performance Measurement of Implementing Manufacturing Execution System
Authors: Chen Kai Ying
Published: March 2009

Manufacturing execution system (MES) is a computer application system that integrates all relevant real-time information along every step in a manufacturing process. MES is essential for manufacturers for gathering real-time production line information, supporting manufacturing decision making and increasing manufacturing efficiency. MES is a must for operation control and lot tracking in the shop floor of a plant with complicated manufacturing processes, such as semiconductor manufacturing fab or TFT-LCD manufacturing plant. This paper presents the
formulization of performance measurement of implementing MES from several quantitative and qualitative aspects by analyzing the basic functions and objectives of MES and interviewing with some senior consultants and MES related working staff. In addition, multi-attribute decision making technique, analytic hierarchy process (AHP) is used to decide the priority of these performance
measurement indices. The results of this research will be useful for a company when MES is an existing system or is a To Be system.
A Hierarchical Self-Organizing Neural Network for Automatic Wafer Defect Inspection
Authors: Chang Chuan Yu , Chang Chia Wei
Published: March 2009

The wafer defect inspection is an important process before die packaging. The defective regions were usually identified through visual judgment with the aid of a scanning electron microscope. Dozens of people visually check dies and mark their regions manually. Thus, potential misjudgment may be introduced due to human fatigue. In addition, the process can incur significant personnel costs. Self-Organizing Neural Networks (SONNs) have been proven to have the
capabilities of unsupervised auto-clustering. In this paper, a hierarchical self-organizing neural networks (HSONN) with consideration of multiple textural information is proposed to replace the traditional electrical testing and the human inspection processes. The proposed HSONN is consists of 3 layers, each layer is a specific cluster to separate the block of wafer image into normal and defective
regions. The suspicious defective regions are used as inputs to the next layer of HSONN for subsequent classification of the defective regions. Through the hierarchical classify, the output of the 3th layer denotes the detecting defective regions. Based on real-world data, the experimental results show that the proposed method successfully identifies the defective regions on wafers with good
performances.
Performance Analysis of a Novel 6-DOF Parallel-Kinematics Machine with Decoupled Motion Characteristics
Authors: Yang Gui Lin , Li Yun Hua
Published: March 2009

This paper is focused on the performance analysis of a newly developed 6-DOF
Parallel-Kinematics Machine (PKM). The design related analysis issues such as the instantaneous kinematics, manipulability, accuracy, and stiffness are addressed. This new PKM has three identical RPRS legs to support the moving platform. Since all joint axes, excluding the three spherical joints at the leg-ends, are parallel to each other and perpendicular to the base plane, this 6-DOF 3RPRS PKM
exhibits decoupled motion characteristics such that translation along the vertical direction and rotation about horizontal axes are only driven by the three active-prismatic joints, while translation in horizontal planes and rotation about vertical axes are mainly driven by the three active-revolute joints. The PKM also has a large cylindrical reachable workspace and high stiffness in vertical directions.
These features make it a promising 6-DOF machine structure for light machining and heavy parts assembly tasks.
Tracking Control of Automatic Pipe Cutting Robot with Magnetic Binder
Authors: Rhim Sung Soo , Lee Soon Geul
Published: March 2009

An automatic pipe cutting/welding robot with a magnetic binder, which is named
APCROM, is developed and its tracking control is studied in this paper. Using magnetic force the four-wheeled mobile robot binds itself to the pipe and executes automatic pipe cutting/welding process. As APCROM rotates around the cylindrical pipe laid in the gravitational field, the gravity effect on the movement of the robot varies. The varying gravitational effect deteriorates the tracking performance of the robot and degrades the quality of the pipe cutting/welding process. To maintain a constant velocity and consistent cutting/welding performance, the authors adopt a repetitive learning controller, which learns through practice the required effort to cancel the tracking errors. Analysis results and experimental results verify the effectiveness of the proposed control scheme.
Precision-Limit Positioning of a Linear Motor Nano Drive System
Authors: Hsieh Chen , Lin Ji-Lung , Huang Jen Chiou , Chen Chih Hong
Published: March 2009

Ultra high precision positioning is an important issue in modern manufacturing industries. As it comes to positioning it is widely believed that friction is detrimental to high precision. As a result, people usually use special mechanical systems such as air-bearing guides and/or hybrid drives in a high precision positioning system to avoid the influence of friction. These strategies, however, increase the operational cost and system complexity. In this paper, it describes how to
apply the Precision-Limit Positioning (PLP) technique introduced in [1] to a standard linear motor system with the existence of friction. The position resolution is designed to equal to the resolution of the position sensor used in the feedback loop, which is 2nm/count. It is further requested that the repeatability and steady state vibration of the system are stable enough so that the table is capable of
doing count-by-count operation.
Modelling of the Development of Initial Crack under Hot Rolling Condition
Authors: Tang Jian Ning , Tieu A. Kiet , Jiang Zheng Yi
Published: March 2009

An oxide scale layer is formed on the steel strip surface due to the high temperature
(850-1100 °C) of the strip in hot rolling. The oxide scale layer may not be continuous because of the defects such as void existing in the layer before the strip enters the roll bite. The non-zero cracks may therefore be formed on the oxide scale layer, especially, when the oxide scale layer is relatively thick. These cracks may become narrower (even become closed) or wider (even form steel substrate
extrusion) after hot rolling deformation. The development of the crack depends on the materials flow in the hot rolling process. The shape of the profile of the oxide scale layer has a significant effect on the materials flow in hot rolling process so it is important to investigate the effect of the oxide scale profile on the propagation of the crack. In this paper, the authors used the FEM method to simulate the
crack propagation in oxide scale under hot rolling conditions for different profile parameters of the oxide scale layer. Simulation results indicate that the larger is the initial profiles surface roughness, the larger the crack width remained after rolling. With a rough profile and large initial crack width, the steel substrate extrusion may be formed.
Study of a Miniature Air Bearing Linear Stage System
Authors: Fan Kuang Chao , Yen R.H. , Ho Chi Chung
Published: March 2009

For the purpose of micro stage used in micro positioning, a miniature aerostatic air bearing linear slide system was studied. Different arrayed micro-hole plates were fabricated. Using focused laser drilling, the diameter of the hole is limited to 300m. However, with the MEMS process, smaller diameters up to 30m could be achieved. A miniature air bearing linear slide was constructed by imbedding three developed air pads in the slider block, which could slide along a small granite
straightedge to form a small sliding stage. The pressure distribution of air pad simulated by the Spectral Element Method was found in good agreement with experimental results. It was also found that the smaller the micro holes the better stability of the floating condition can be obtained. Straightness tests of the developed miniature air bearing sliding stage are carried out to show its
feasibility.
Mechanical Characterization of Thin Films by the Capacitance-Voltage Measurement of Microstructures
Authors: Hu Yuh Chung , Gau Wei Hsin , Tu Wei Hsiang
Published: March 2009

This paper presents a novel and high-precision technology for extracting the Young’s modulus of thin films through the capacitance-voltage (C-V) measurement of microstructures. An algorithm considering the electric-mechanical coupling effect and the distributed character of microstructures is developed for extracting the Young’s modulus through the C-V measurement of microstructures. The average error percentage of the extracted Young’s modulus of single-crystalline silicon is below 1% and the high precision and repeatability of the present methodology are verified. Since the driving and response signals are both electric, they could be accomplished using existing semiconductor testing equipments through probing on the bonding pads of devices. Because hardware
replacement could be avoided, this methodology shows substantial advantage over other property-extraction methods for large-scale implementation in semiconductor or MEMS fabs.
Development of a Novel Micro Wire-EDM Mechanism for the Fabricating of Micro Parts
Authors: Lin Chang Sheng , Liao Yunn Shiuan , Chen Shun Tong
Published: March 2009

The wire running system of the tabletop Wire-EDM machine for making intricate micro parts developed in our previous study is improved in the paper. A very simple but novel micro-wire cutting mechanism that allows the use of the thin wire of a diameter as small as 20μm is designed. The vibration of the micro wire is suppressed by implementing a unique tension control principle and
vibration absorbers. In actual machining the workpiece is mounted on the spindle having indexing ability. By proper planning the wire moving path, micro gear, micro turbine, micro screw, etc. can be manufactured. In the paper the micro bevel gear, which has special appearance and is very difficult if not impossible to be machined by other micro fabrication technologies, is also manufactured
satisfactorily.
Experimental Analysis for Low-Temperature Poly-Si Films Produced by Using the Excimer Laser Annealing Method
Authors: Chen Yu Ru , Chao Long Sun
Published: March 2009

This paper is to investigate the effects on grain size of different working conditions for making poly Si films by using the excimer laser annealing method. In this research, a KrF excimer laser of 248 nm in wavelength is used to irradiate a-Si films of 0.1 μm in thickness on glass substrate to produce poly-Si ones. The control parameters are laser intensity (200~500 mJ/cm2), pulse number
(1~10 shots) and coverage fraction (0~100%). Besides, the effect of a SiO2 layer is also studied, which is utilized as a heat-isolated zone located between the Si film and glass substrate. Average grain sizes from SEM photos are used to analyze the effects of these parameters. Purely from the heat transfer view, the Si film obtains more energy would have the slower cooling or solidification rate,
which results in the larger grain. From the experimental results, if the melt pool is within the range of Si film or does not contact its neighboring layer (SiO2 layer or glass substrate), the more absorbed energy from the higher energy intensity, the larger pulse number or the bigger coverage fraction can have the larger average grain size. However, with large enough energy, the melt pool could go through
the Si film and touch the lower layer. This would induce much more nuclei due to the homogeneous nucleation in the pool and the heterogeneous nucleation near the interface between the film and the neighboring layer. The resulting grain size is much smaller than that of the former one. The transition points of these two cases for different control parameters can be obtained from the experimental
results in this study. When the energy from the laser is small, the SiO2 layer acts like a heat absorber and makes the grain size smaller than that of not having the SiO2 layer. On the other hand, when the energy is large, the SiO2 layer becomes a heat insulator and makes the grain size larger.
Fabrication and Mechanical Properties of Glass Fiber/Epoxy Nanocomposites
Authors: Tsai Jia Lin , Kuo Jui Ching , Hsu Shin Ming
Published: March 2009

This research is aimed to fabricate glass fiber/epoxy nanocomposites containing
organoclay as well as to understand the organoclay effect on the in-plane shear strength of the
nanocomposites. To demonstrate the organoclay effect, three different loadings of organoclay, were
dispersed in the epoxy resin using mechanical mixer followed by sonication. The corresponding
glass/epoxy nanocomposites were prepared by impregnating the organoclay epoxy mixture into the dry glass fiber through a vacuum hand lay-up process. Off-axis block glass/epoxy nanocomposites were tested in compression to produce in-plane shear failure. It is noted only the specimens showing in-plane shear failure mode were concerned in this study. Through coordinate transformation law,
the uniaxial failure stresses were then converted to a plot of shear stress versus transverse normal stress from which the in-plane shear strength was obtained. Experimental results showed that the fiber/epoxy nanocomposite exhibit higher in-plane shear strength than the conventional composites. This increased property could be ascribed to the enhanced fiber/matrix adhesion promoted by the
organoclay.
Precise Riveting Systems Using Networked PLCs for Remote Monitoring and Control via the Internet
Authors: Lin Hsiung Cheng
Published: March 2009

Today, Programmable Logic Controllers (PLCs) are widely used at the modern
manufacturing automation. With an increasing demand for networking facility as well as a natural, intuitive man-machine interaction in automated industry, the graphical programming for multi-PLC control is gaining much attention nowadays. This paper develops a PC-based virtual instrument (VI) that can carry out a remote monitoring and control for up to eight-PLC-based precise riveting systems via the Internet. The real-time implementation shows its good performance and presents the
illustrative demonstration.
Electronic Circuit Simulation and Digital PC-Based Implementation of Dynamic MRR Optimization
Authors: Lan Tian Syung , Hsu Kuei Shu , Chu Tung Te , Yeh Long Jyi , Her Ming Guo
Published: March 2009

Dynamic MRR (material removal rate) modeling is constructed and optimum solution through Calculus of Variations in maximize the machining profit of an individual cutting tool under fixed tool life is introduced. The mathematical model is formulated by reverse experiments on an ECOCA PC-3807 CNC lathe, and the electronic circuit is developed using linear regression technique for virtual machining. The inaccuracy between actual and simulated voltage is assured to
be within 2%. By introducing a real-world CNC (computerized numerical control) machining case from AirTAC into the virtual system, the simulated cutting forces are shown to promise the feasible applicability of the optimum MRR control. Additionally, the implementation of dynamic solution is experimentally performed on a proposed digital PC-based lathe system. The surface roughness of all machined work-pieces is found to not only stabilize as the tool consumed, but also accomplish the
recognized standard for finish turning.
A Study on Fuzzy Logic Theory to Predict the Process Parameters in GMA Welding Process
Authors: Kim Ill Soo , Son Joon Sik , Kim H.H. , Kim I.J. , Kang B.Y.
Published: March 2009

Recently, there has been a rapid development in computer technology, which has in turn led to develop the automated welding system using Artificial Intelligence (AI). However, the automated welding system has not been achieved duo to difficulties of the control and sensor technologies. In this paper, the classification of the optimized bead geometry such as bead width, height, penetration and bead area in the Gas Metal Arc (GMA) welding with fuzzy logic is presented. The Fuzzy C-Means (FCM) algorithm, which is best known an unsupervised fuzzy clustering
algorithm is employed here to analysis the specimen of the bead geometry. Then the quality of the GMA welding can be classified by this fuzzy clustering technique, and the optimal bead geometry can also be achieved.
Applications of LIGA on Micro-Punching Process for Metallic Materials
Authors: Pan C.T. , Cheng P.J. , Shen S.C. , Chen M.F. , Wang R.Y. , Chou Min Chie , Wu Tung Chuan
Published: March 2009

This study presents an innovative imprinting method to fabricate IC devices by
micro-punch process. Normally, imprinting method is used to imprint plastic materials such as photoresist and polymeric materials. In this study, imprinting process is applied to micro-punch metallic materials directly for IC devices. Fabrications of IC devices with high aspect ratio structures ranging from micrometer to sub-micrometer are described. In this study, to keep the production costs as low as possible, a complete micro-punching process is applied to replicate IC devices. A combination of lithography, extra-hard alloy nickel cobalt (Ni/Co) electroplating process (as a metal imprint mold for punch) and chemical mechanic polishing (CMP) process is used to flat the extra-hard alloy micro-punch head. It is worth noticing that the Ni-Co electroplating process with hardness over Hardness of Vicker (Hv) 560 is developed. With such hardness, it can stand the high pressure and abrasivness to confine the accuracy during micro-punching process. With regard to the
electroplating process, Ni-Co is deposited and covered on the photoresist template uniformly by electroplating. The Ni/Co mold is served as master for micro-punching process to replicate the pattern onto polyimide (PI) or copper sheets. Finally, the experimental results are measured and characterized.
Analysis for Repairing the Cracked PVC Pipe
Authors: Lee Kuang Chyi , Liang Yuan Cheng , Lin Chien Chang
Published: March 2009

This paper proposes a stress analysis model for the cracked PVC pipe. The cracked PVC pipe is rehabilitated with an inner composite epoxy material by a dig-free method. The optimal thickness which can get the maximal flow rate after rehabilitated will be found by the finite element model. When the crack width of the pipe with 324 degree crack angle is 30 mm, the optimal thicknesses will be obtained with the compression ratio of 5%. The optimal thicknesses of theφ 300 ,φ 400 , φ 500 and φ 600 PVC pipes are 0.6, 0.8, 1.1 and 2.5 mm respectively. With these
optimal thicknesses, the flow rates of rehabilitated pipes are lager than 98% the flow rates of original pipes.
Tool Path Planning for Edge Quality Enhancement in Planar Milling of Free Form Contours
Authors: Chu Chih Hsing
Published: March 2009

One of the most effective methods for enhancing edge quality is to prevent the tool from exiting the work part in a machining operation. Exit here refers specifically to the tool cutting edges moving out of the part at an edge while removing material. Only entrance burrs are allowed to occur in this condition, resulting in less serious edge defects. This study presents a two-stage geometric algorithm for avoiding tool exits in planar milling of 2D free form contours. The cutter positions causing the tool to exit the part are first detected; then a heuristic scheme is applied to generate new
cutter locations with no tool exits. Experimental results show that edge quality is significantly improved. This work provides a feasible method for reducing edge defect in an automatic manner without the need of edge finishing, which is highly advantageous in meso-scale machining.
Size Effects on Sheet-Metal Formability for Miniature Parts
Authors: Hsu Quang Cherng
Published: March 2009

Due to the rapid progress of industrial development, the formation of lightweight and
small-size parts is becoming increasingly important. Especially in the IC and 3C industry, the sheet metal forming of miniature parts is especially interesting. Size effects such as specimen dimension, blank thickness, punch corner dimension, grain size, and grid dimension (for strain measurement), as well as the microstructure of material and surface condition all seriously influence the forming of
miniature parts. In this paper, systematic experiments including Erichsen stretch forming and hydraulic bulge, and strain analyzers including for circular and rectangular grids are described for establishing the relationships of sheet metal formability to process parameters. The details of the
experimental procedures and results are presented and discussed.
Highly Sensitive Infrared Temperature Sensor for CMOS Compatible Thermopiles
Authors: Huang Chun An , Shen Chih Hsiung
Published: March 2009

A high-sensitivity infrared detector requires small thermal capacitance and small thermal conductance to maximize the temperature change and signal induced by incident IR radiation. The suspended structure of infrared sensors provides ideal, thermally isolated, structures for support of the thin film detector. A new idea of improving CMOS thermopile performance is introduced to reduce the thermal conductance by dividing the thermocouple into several segments, which greatly increase the heat flow barrier. Then, adjacent segments are connected by a minimum width of alumina wire, which change the heat path and accumulated heat at the joint points. Several designs of infrared microsensors can improve performance of signal with reduce of thermal conductance. To that end, by using some adequate designs of polysilicon architecture, we can greatly reduce the heat flow from the
main stream without introducing further electric resistance, which is related with noise. The design and simulation of thermopile sensors are realized by using the process parameters of standard 0.351m CMOS IC technology. Firstly we develop such a structure of thermopile with low thermal conductance and high performance by using CMOS compatible process which can be easily and naturally fabricated. The simulation results show good match with our original idea and great performance than before.