bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical Properties and Chain Orientation in Single Point Incremental Forming of Semi-Crystalline Polyamide
Authors: Davarpanah Mohammad Ali , Bansal Shalu , Malhotra Rajiv
Published: September 2016

Incremental forming is an emerging technique for reducing the cost of tooling, increasing the flexibility and reducing the thermal energy usage in forming of thermoplastic polymer surfaces. This paper examines the effect of Single Point Incremental Forming (SPIF) on the mechanical properties of a semi-crystalline Polyamide (Nylon 66) material. The effects of incremental depth and tool rotation speed on these properties, and on the sheet temperature during forming are quantified. Differential Scanning Calorimetry and X-ray Diffraction are performed to understand changes in crystallinity and chain orientation of the polymer due to SPIF. It is found that the formed material has a substantial higher toughness and ductility, but reduced yield stress and Young’s modulus, as compared to the formed material. Stress relaxation tests show similar relaxation behavior for the formed and unformed polymer. The effect of SPIF on the chain orientation and its link to the mechanical properties are discussed.
Speculations on the Market Evolution of Cloud Manufacturing
Authors: Wang Yijing , Peng Tao
Published: September 2016

To address the latest challenges in the service-oriented manufacturing paradigm, cloud manufacturing is proposed for not just large-scale enterprises, but also small- and medium-sized enterprises (SMEs). Although enterprises acknowledge its technical merits, many of them hold their actions until further proof. This paper studies specifically the market evolution of cloud manufacturing from an economic perspective. The anticipated development trend is presented based on game theory and equilibrium analysis. Three major stages, emerging, growing and maturing, are partitioned with interactions among cloud players, i.e. service provider, service consumer and service platform operator (INP). In each stage, both static and dynamic market behaviors are analyzed using classical economics models. Service providers and consumers with different levels of knowledge will act distinctly, this requires an INP to offer diverse strategies to match their profit expectations. The findings in this paper can help enterprises, particularly SMEs, to understand and evaluate their business strategies, and provide economic evidence that participating in shaping a “health” cloud manufacturing market is worthwhile.
A New Approach for Online Monitoring of Additive Manufacturing Based on Acoustic Emission
Authors: Wu Haixi , Yu Zhonghua , Wang Yan
Published: September 2016

Despite its recent popularity, additive manufacturing (AM) still faces many technical challenges for the insufficiency of process reliability, controllability, and product quality. To enhance the process repeatability, effective in-situ monitoring methods for AM processes are needed. In this study, an online monitoring method for AM process failure detection is proposed, where acoustic emission (AE) is applied as the sensing technique. Its application to polymer material extrusion, also known as the technology of fused deposition modeling (FDM), is demonstrated. Experimental results show that the proposed monitoring method allows for the real time identification of major process failures. The occurring time of major failures and failure modes can be identified by analyzing the time- and frequency-domain features of AE hits respectively. A K-means clustering algorithm is applied to verify and demonstrate the classification procedure. The automated failure identification can reduce the waste of fabrication with enhanced machine intelligence.
A Comparison Between Porous NiTi and Ti-6Al-4V Fixation Hardware on Bone Remodeling After a Reconstruction Surgery
Authors: Raad Bahram , Shayesteh Moghaddam Narges , Elahinia Mohammad
Published: September 2016

The aim of this article is to investigate the effect of two different fixation hardware materials on bone remodeling after a mandibular reconstruction surgery and to restore the mandible’s function, healthy appearance, mastication, swallowing, breathing, and speech. The hypothesis is that using fixation hardware with stiffness close to that of the surrounding bone will result in a more successful healing process in the mandible bone.

The finite element model includes the material properties and forces of the cancellous bone, cortical bone, ligaments, muscles, and teeth. The reconstruction surgery is modeled by including the fixation hardware and the grafted bone. In the sectioned mandible, to best mimic the geometry of the mandible, two single barrel grafts are placed at the top of each other to form a double barrel graft set. Two different materials were used as the mandibular fixation parts, stiff Ti-6Al-4V, and porous superelastic Nickel-Titanium (NiTi) alloys.

A comparison of these two alloys demonstrates that using porous NiTi alloy as the fixation part results in a faster healing pace. Furthermore, the density distribution in the mandibular bone after the healing process is more similar to the normal mandible density distribution.

The simulations results indicate that the porous superelastic NiTi fixation hardware transfers and distributes the existing forces on the mandible bone more favorably. The probability of stress shielding and/or stress concentration decrease. This type of fixation hardware, therefore, is more appropriate for mandible bone reconstruction surgery.
Effect of Reprocessing on the Rheological, Electrical and Mechanical Properties of Polypropylene/Carbon Nanotube Composites
Authors: Stan Felicia , Sandu Laurentiu Ionut , Fetecau Catalin , Rosculet Razvan Train
Published: September 2016

In the near future, carbon nanotubes containing plastic parts are likely to enter the environment in large quantities and, due to their resistance to degradation, the environmental impact may be even more important than that of similarly shaped plastic products. Thus, there is an immediate need to examine and understand the effect of recycling on the properties of polymer/carbon nanotube composites in order to develop sustainable recycling technologies.

In this paper, polypropylene filled with different levels of multi-walled carbon nanotubes (MWCNTs) manufactured by injection molding was closed-loop recycled in order to investigate the effect of recycling and reprocessing on its rheological, electrical and mechanical properties. Preliminary results show that the PP/MWCNT composites keep the flow performance after mechanical recycling. Moreover, the stress and strain at break increase after one reprocessing cycle (mechanical recycling coupled with injection molding) whereas no statistically significant changes in electrical conductivity, Young modulus and tensile strength of the PP/MWCNT composites filled with 1, 3 and 5 wt.% were observed.
Laser Sintered Graphene Reinforced Titanium Matrix Nanocomposites
Authors: Hu Zengrong , Tong Guoquan , Xu Rong , Zhao Lirun , Chen Changjun , Zhang Min , Sun Yilin , Guo Huafeng , Xu Jiale
Published: September 2016

Graphene reinforced titanium (Ti-Gr) nanocomposites have been prepared on AISI 4140 base plate by laser sintering process. The dispersion and survival of graphene in the Ti matrix after laser treatment were discussed. Through laser sintering, graphene sheets were dispersed uniformly into Ti matrix to form Ti-Gr nanocomposites. Microstructures and components of the nanocomposites were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and Raman spectroscopy. It was proved by SEM images, XRD patterns and Raman spectrum that graphene survived in Ti-Gr nanocomposites after laser sintering. Hardness measurements showed the laser sintered Ti-Gr nanocomposites got more than 2-fold higher in Vickers Hardness value than that of laser sintered Ti.
Towards Business Process Catalog for Cloud-Enabled Service Oriented Architectures
Authors: Ivezic Nenad , Ljubicic Miroslav , Kulvatunyou Serm , Nieman Scott , Leiva Conrad , Marjanovic Zoran
Published: September 2016

Advances in cloud-enabled service-oriented architectures (SOA) have caused a resurgence of industry interest in business process catalog as a vehicle for establishing shared references for collaborative business processes. With this paper, we start to explore the state of art and practice in business process catalog and classification scheme (BPCCS) development and use for the manufacturing industry. More specifically, this paper includes two major contributions. First, we identify a set of initial requirements for BPCCS. Second, we provide a use-case analysis based on the identified requirements. We end by comparing our BPCCS requirements with those being developed across other, BPCCS R&D groups.
Ligament Flows of Exit-Pinching During Drop-on-Demand Inkjetting of Alginate Solution
Authors: Zhang Mengyun , Xu Changxue
Published: September 2016

Organ printing is an emerging technology for fabricating artificial tissues and organs, which are constructed layer by layer by precisely placing tissue spheroids or filaments as building blocks. These fabricated artificial organs offers a great potential as alternatives to replace the damaged human organs, providing a promising solution to solve organ donor shortage problem. Inkjetting, one of the key technologies in organ printing, has been widely developed for organ printing because of its moderate fabrication cost, good process controllability and scale-up potentials. Droplet formation process as the first step towards inkjetting 3D cellular structures needs to be studied and controlled precisely. This paper focuses on the ligament flow of exit-pinching during droplet formation process of inkjet printing. The ligament flow directions during pinch-off process of inkjet printing of a sodium alginate solution with a concentration of 0.5% (w/v) have been studied. It is found that two different types of flow directions inside a single ligament during pinch-off process may occur. At an excitation voltage of 30 V, the ligament flow has two different directions at the locations near the nozzle orifice and the jet front head: the negative z direction at the location near the nozzle orifice due to the dominant capillary effect, and the positive z direction at the location near the jet front head due to both the fluid inertial and capillary effects. On the contrary, at an excitation voltage of 70 V, the ligament flow directions are the same at the locations near the nozzle orifice and the jet front head: the positive z direction at the location near the nozzle orifice due to the sufficiently large fluid inertial effect, and the same positive z direction at the location near the jet front head due to both the fluid inertial and capillary effects. Two flow directions inside a single ligament benefit single droplet formation without satellite droplets, but the droplet trajectory will be easily affected by the airflow in the laboratory due to the small droplet velocity as well as the droplet deposition accuracy. Single flow direction inside a single ligament usually results in a long ligament due to the large fluid inertia which eventually breaks into several undesirable satellite droplets. The resulting knowledge will be beneficial for better understanding of the ligament pinch-off during droplet formation process of inkjet printing biological viscoelastic alginate bioink for 3D cellular structure fabrication as well as precise droplet controllability for good quality of fabricated 3D structures.
Sustainability of 3D Printing: A Critical Review and Recommendations
Authors: Liu Zhichao , Jiang Qiuhong , Zhang Yang , Li Tao , Zhang Hong-Chao
Published: September 2016

3D printing has been recognized as an efficient and sustainable technology in the fields of advanced manufacturing. In the past few years, a considerable research, including basic theoretical research, technology innovation and industries application, have been conducted to promote 3D printing for a better performance in manufacturing. However, the benefits of 3D printing from environmental perspective are still to be seen and its sustainability is also a mystery. This paper presents a critical review about the qualitative and quantitative environmental impact of 3D printing to provide a comprehensive understanding of 3D printing for the public and provide a better guide for the future research. In addition, based on the principle of multi-objective optimization, this paper proposes a novel framework for 3D printing processes sustainability assessment and improvement by integrating the product Computer Aided Design (CAD) and Life Cycle Assessment (LCA). At last, recommendations about major concerns when analyzing the sustainability of 3D printing are put forward, which might be considered for the coming research.
Conceptual Prototypes of Composite Structures for Aerospace
Authors: Santo L. , Quadrini F. , Bellisario D. , Accettura A. G.
Published: September 2016

Shape memory composites (SMCs) are very interesting for self-deployable structures in aerospace applications. SMCs have been widely developed but not yet fully applied to space. In this study a lab-scale production of SMC prototypes for aerospace is described. Conceptual design of small-scale structures were prototyped with the aim to define several configurations which are able to self-deploy. SMC prototypes were manufactured by using two layers of carbon/epoxy prepreg with a shape memory epoxy resin interlayer. Two different configurations were produced to prototype complex shape for multiple folding and 3D deployments of de-orbiting structures. In particular, the first prototype tests a de-orbiting system without the sail to study the complex folding and de-folding mechanisms. The second configuration evaluates a de-orbiting dual-sail for satellite applications. The SMC structures were produced in the opened shape and subsequently memorized in the closed configuration. The initial deployed configuration is recovered by heating the prototype. The closed configuration increases the packing efficiency of large structures for space orbiting systems. The shape memory properties were provided only to folding zones. Memory-recovery-cycles have been performed to test SMC performances. As a result, the two configurations can successfully self-deploy following the desired design constraints and recovering the original flatness without noticeable defects.
Micro-Machinability Studies of Single Crystal Silicon Using Diamond End-Mill
Authors: Choong Zi Jie , Huo Dehong , Degenaar Patrick , O’Neill Anthony
Published: September 2016

This paper presents the research on the machinability studies in micro-milling of (001) silicon wafer. Excessive generation of undesirable surface and subsurface damages such as surface edge chipping often occurs when machined at depth of cut of several hundreds of microns. Ideal machining strategy to reduce the generation of edge chipping is required. Investigations on the effect of machining conditions on the cutting performances and size effect on the specific cutting energy in silicon micro-milling were conducted. These investigations provide understandings on the behavior of cutting mechanism during machining and helps to identify suitable machining parameters for fracture free machining using diamond end mills. Full slot milling were performed along <100> and <110> directions on a (001) surface wafer under various machining conditions. Results show that machined surfaces along <100> were of better quality than those along <110> and is in agreement with previous studies. Furthermore, good machining quality was achieved when machined at depth of cut of 10 μm or feed per tooth of 0.075 μm/tooth, regardless of the machining conditions. In addition, investigation for the size effect on specific cutting energy also shows that brittle mode machining begins when feed per tooth increases beyond 0.4 μm/tooth.
Simulation of Cross-Sectional Geometry During Laser Powder Deposition of Tall Thin-Walled and Thick-Walled Features
Authors: Bourne Keith A. , Farahmand Parisa , Roberson David
Published: September 2016

A model of the laser powder deposition (LPD) process is presented, which predicts the cross-sectional geometry of parts that are made up of thin-walled and thick-walled features, deposited via multiple passes. The model builds up the part shape incrementally by predicting the cross-section of a bead of material deposited on the part, updating part shape to reflect the added material, and repeating for each additional deposition pass. The effects of laser power and deposition speed are accounted for empirically, and the effect of nozzle stand-off distance is accounted for via a powder catchment model suitable for coaxial deposition nozzles. The model was calibrated via deposition experiments using stainless steel 316L powder and via measurement of nozzle characteristics. Validation tests showed that the powder catchment model captured the effect of nozzle stand-off distance on deposited bead size. Validation tests also showed that the model predicted the overall shapes of both thin-walled and thick-walled features, including rounding present at the edges of some thick-walled features. Using calibration data from short thick-walled depositions, the average error in predicted feature height, after ten layers, was 9.3% and 9.5% for thin-walled and thick-walled features, respectively. The model was also shown to predict the effects of using a step-up distance per layer that is too small, resulting in inefficient deposition, or too large, resulting in deposition failure after a few layers.
Parametric Study on Wall Springback in Tailor Welded Long Channels
Authors: Nikhare Chetan P.
Published: September 2016

The common challenge found in cases of high elasticity or high strength or both property materials after forming is springback. The part unloaded after forming tends to recover elastically and the displacement due to elastic recovery is called springback. In this paper, the 3D channels with large length were deformed numerically and parametric study on the wall springback at different section was predicted. For this purpose tailor welded blank was considered. The geometric change along the long axis was also discussed. In addition the effect of parameters on wall springback was also analyzed. The new division factor was included to normalize the springback based on thickness and strength. It was found that the strength ratio and die and punch radius were the top influencing factor for front edge and weld line springback while thickness ratio was the most affecting parameter for the back edge springback.
Fabricating Microchannels in Elastomer Substrates for Stretchable Electronics
Authors: Yuen Michelle C. , Kramer Rebecca K.
Published: September 2016

As flexible devices and machines become more ubiquitous, there is a growing need for similarly deformable electronics. Soft polymers continue to be widely used as stretchable and flexible substrates for soft electronics, and in particular, soft sensing. These soft sensors generally consist of a highly elastic substrate with embedded microchannels filled with a conductive fluid. Deforming the substrate deforms the embedded microchannels and induces a change in the electrical resistance through the conductive fluid. Microchannels, thus, are the foundation of flexible electronic devices and sensors. These microchannels have been fabricated using various methods, where the manufacturing method greatly impacts device functionality. In this paper, comparisons are made between the following methods of microchannel manufacturing: cast molding, 3D printing of the elastomer substrate itself, and laser ablation. Further processing of the microchannels into flexible electronics is also presented for all three methods. Lastly, recommended ranges of microchannel sizes and their associated reproducibility and accuracy measures for each manufacturing method are presented.
Assessment of the Effects of Microgrooved Cutting Tool on the Machining Induced Residual Stress in Machining of Ti-6Al-4V
Authors: Qiu Changqing , Ma Jianfeng , Lei Shuting
Published: September 2016

In this paper, the effects of microgroove textured cutting tools on the residual stress on the machined surface of drying three-dimensional turning of Ti-6AL-4V are investigated using Finite Element Method (FEM). Microgrooves are designed and fabricated on the rake face of cemented carbide (WC/Co) cutting inserts. Specifically, the following microgroove parameters are examined: microgroove width, microgroove depth, and edge distance (the distance from cutting edge to the first microgroove). Their effects are assessed in terms of the circumferential residual stress. It is found that microgroove textured cutting tools can lower the detrimental tensile residual stress and induce beneficial compressive residual stress on the machined surface. The microgroove width, microgroove depth, and edge distance all have influence on residual stress on the machined surface in their own ways. This research provides insightful guidance for optimizing the fatigue life of the components by inducing beneficial compressive residual stress on the machined surface.
Knowledge-Based Production Planning Within the Reference Planning Process Supporting Manufacturing Change Management
Authors: Gernhardt Benjamin , Vogel Tobias , Givehchi Mohammad , Wang Lihui , Hemmje Matthias
Published: September 2016

The manufacturing of a product takes place in several partial steps and these mostly in different locations to save tax or to use the best providers. Therefore, in the era of Internet of Things (IoT) and modern Intelligent Production Environments (IPE) are going to be inevitably based on a cloud-based repository and distributed architecture to make data and information accessible everywhere as well as development processes and knowledge available for worldwide cooperation. Semantic approaches for knowledge representation and management as well as knowledge sharing, access, and re-use can support Collaborative Adaptive Production Process Planning (CAPP) in a flexible, efficient, and effective way. Thus, semantic representations of such CAPP knowledge integrated into a machine readable process formalization is a key enabling factor for sharing such knowledge in cloud-based knowledge repositories supporting CAPP scenarios as required for e.g., Small and Medium Enterprises (SMEs). When such contributors work together on a product component production planning, they exchange component production and manufacturing change information between different planning subsystems which require, e.g., a standardized product-feature- and production-machine feature representation. These data exchanges are mostly based on applying the already established Standard for the Exchange of Product model data (STEP) for the computer-interpretable representation and exchange of product manufacturing information. Furthermore, the planning process can be supported by so-called Function Block (FB) based knowledge representation models, serving as a high-level planning-process knowledge-resource template. Web-based and at the same time Cloud-based tool suites, which are based on process-oriented semantic knowledge-representation methodologies, such as Process-oriented Knowledge-based Innovation Management (German: Wissens-basiertes Prozess-orientiertes Innovations Management, WPIM) can satisfy the needs of representing such planning processes and their knowledge resources. In this way, WPIM can be used to support the integration and management of distributed CAPP knowledge, as well as its access and re-use in Manufacturing Change Management (MCM) including Assembly-, Logistics and Layout Planning (ALLP). Therefore, also a collaborative planning and optimization for mass production in a machine readable and integrated representation is possible. On the other hand, that knowledge can be shared within a cloud-based semantic knowledge repository. To integrate all these functionalities, this paper introduces a new method, called Knowledge-based Production Planning (KPP) and outlines the advantages of integrating CAPP with Collaborative Manufacturing Change Management (CMCM). In this way, an enabling basis for achieving ALLP interoperability in Distributed Collaborative Manufacturing and Logistics will be demonstrated.
Automated Learning of Operation Parameters for Robotic Cleaning by Mechanical Scrubbing
Authors: Kabir Ariyan M. , Langsfeld Joshua D. , Zhuang Cunbo , Kaipa Krishnanand N. , Gupta Satyandra K.
Published: September 2016

The task of cleaning surfaces where foreign particles are removed by mechanical scrubbing requires oscillatory motions of the cleaning tool. Selecting the optimal operation parameters is important to automate this task with robots. The operation parameters can be the tool speed, force applied to the surface, frequency and amplitude of tool oscillation, stiffness offered by the robot, etc. The optimal set of parameters will be different for different surface/stain profiles and physical limitations of the robot. A large number of cleaning experiments need to be done if we try to find the optimal parameters exhaustively in a high dimensional space. It will also take a significant number of experiments to find the right model for the cleaning function and predict the optimal cleaning parameters under supervised learning settings. Conducting large number of experiments is often not feasible. We describe a semi-supervised learning approach to reduce the number of cleaning experiments to automate the process of finding the optimal cleaning parameters for arbitrary surface/stain profiles. This generalized method is also applicable for the tasks of grinding and polishing. Results from experiments with two Kuka robots performing cleaning tasks show the validity of our approach.
Resolving Occlusions Through Simple Extraction Motions in Robotic Bin-Picking
Authors: Kaipa Krishnanand N. , Shriyam Shaurya , Kumbla Nithyananda B. , Gupta Satyandra K.
Published: September 2016

In this paper, we address the complexities arising due to occlusions in robotic bin-picking. Our focus is on mixed-bins. Most traditional planners try to find collision-free paths to extract objects, while returning a failure whenever a collision is anticipated between the object to be extracted and a neighboring object occluding the former. We take a different approach in this paper. Our approach is inspired by the fact that simple motions of the grasped object may result in the transition of the object from a collision-state to a collision-free state. Our approach exploits the local geometric relationships between the objects in contact with each other and the change in these relationships as the grasped object is moved to make conservative predictions whether such motion results in tangle-free extraction. We demonstrate our approach using experiments with a Kuka LBR iiwa robot singulating objects from a pile of convex and concave objects.
Prediction of Coupled Torsional-Axial Vibrations of Drilling Tool With Clamping Boundary Conditions
Authors: Jin Xiaoliang , Koya Narahara Gopal
Published: September 2016

Coupled torsional-axial vibrations of the drilling tool play a significant role in the machining dynamics of the drilling process. In this paper, the torsional-axial vibrations of the drilling tool due to the warping deformation of the pretwisted flute is modeled. An enhanced receptance coupling model is developed to predict the coupled torsional-axial vibrations of the drilling tool considering the dynamics of fixture and clamping conditions. Rigid and flexible receptance coupling methods are used, with the simulation results verified through modal experiments. The proposed model is able to provide optimum drilling tool configurations to avoid undesired tool vibrations and improve hole quality.
Projection Micro-Stereolithography of Temperature Responsive Mechanically Tough Hydrogels
Authors: Han Daehoon , Lu Zhaocheng , Lee Howon
Published: September 2016

Temperature responsive hydrogel has attracted considerable attention as an outstanding material for creating a variety of reconfigurable structures. As a well-known temperature responsive hydrogel, poly(N-isopropylacrylamide) (PNIPAAm) has been widely used in various applications. Here, we report high resolution 3D micro fabrication of PNIPAAm structures using projection micro-stereolithography (PμSL). We also show the controllability of degree of swelling and transition temperature of 3D printed PNIPAAm structures by controlling process parameters of PμSL. In addition, we demonstrate improvement of mechanical properties of PNIPAAm by introducing ionic crosslinks into 3D printed PNIPAAm structures to form ionically and covalently crosslinked hybrid networks.
Materials Testing of 3D Printed ABS and PLA Samples to Guide Mechanical Design
Authors: Farbman Daniel , McCoy Chris
Published: September 2016

A set of monotonic tensile tests was performed on 3-D printed plastics following ASTM standards. The experiment tested a total of 13 “dog bone” test specimens where the material, infill percentage, infill geometry, load orientation, and strain rate were varied. Strength-to-weight ratios of the various infill geometries were compared. It was found through tensile testing that the specific ultimate tensile strength (MPa/g) decreases as the infill percentage decreases and that hexagonal pattern infill geometry was stronger and stiffer than rectilinear infill. However, in finite element analysis, rectilinear infill showed less deformation than hexagonal infill when the same load was applied. Some design guidelines and future work are presented.
3D Printing in Cloud Manufacturing: Model and Platform Design
Authors: Ren Lei , Wang Shicheng , Shen Yijun , Hong Shikai , Chen Yudi , Zhang Lin
Published: September 2016

Although 3D printing has attracted remarkable attention from both industry and academia society, still only a relatively small number of people have access to required 3D printers and know how to use them. One of the challenges is that how to fill the gap between the unbalanced supply of various 3D printing capabilities and the customized demands from geographically distributed customers. The integration of 3D printing into cloud manufacturing may promote the development of future smart networks of virtual 3D printing cloud, and allow a new service-oriented 3D printing business model to achieve mass customization. This paper presents a primary 3D printing cloud model and an advanced 3D printing cloud model, and analyzes the 3D printing service delivery paradigms in the models. Further, the paper proposes a 3D printing cloud platform architecture design to support the advanced model. The proposed advanced 3D printing cloud model as well as the architecture design can provide a reference for the development of various 3D printing clouds.
Three-Dimensional Modification in Silicon With Infrared Nanosecond Laser
Authors: Yu Xiaoming , Trallero-Herrero Carlos A. , Grojo David , Lei Shuting
Published: September 2016

Motivated by previous work on three-dimensional (3D) fabrication inside dielectrics, we report experimental results of 3D modification inside intrinsic silicon wafers using laser pulses with 1.55 μm wavelength and 3.5 ns pulse duration. Permanent modification in the form of lines is generated inside silicon by tightly focusing and continuously scanning the laser beam inside samples, without introducing surface damage. Cross sections of these lines are observed after cleaving the samples, and are further analyzed after mechanical polishing followed by chemical etching. With the objective lens corrected for spherical aberration, tight focusing inside silicon is achieved and the optimal focal depth is identified. The laser-induced modification has a triangular shape and appears in front of the geometrical focus, suggesting significant absorption in those regions and resulting in reduced energy density. The morphology of modified regions is found to be dependent on the laser polarization.
Effect of Nanocrystallization-Assisted Nitriding on the Corrosion Behavior of AISI 4140 Steel
Authors: Ren Zhencheng , Hou Xiaoning , Dong Yalin , Ye Chang
Published: September 2016

In this study, an innovative process called nanocrystallization-assisted nitriding was used to process 4140 steels. First, a nanocrystalline surface layer was induced in 4140 steel by ultrasonic nanocrystal surface modification (UNSM). The abundant nanoscale grain boundaries provide micro-channels for efficient nitrogen diffusion during nitriding at relatively low temperature (450 °C) and short duration (4 hours). The samples were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The hardness and corrosion resistance were examined and compared for samples after different processing conditions. It has been demonstrated that the sample processed by nanocrystallization-assisted nitriding has much higher hardness and corrosion resistance compared with the samples processed by nitriding only.
Microstructure Sensitive Flow Stress Based on Self Consistent Method
Authors: Zhang Xueping , Shivpuri Rajiv , Srivastava Anil K.
Published: September 2016

Flow stress in the high speed machining of titanium alloys depends strongly on the microstructural state of the material which is defined by the composition of the material, its starting microstructure and the thermo-mechanical loads imposed during the machining process. Previous researchers have determined the flow stress empirically as a function of mechanical state parameters such as strain, strain rate and temperature while ignoring the changes in the microstructural state such as alpha-beta phase transformations. This paper presents a new microstructure sensitive flow stress model based on the self-consistent method (SCM) that includes the effects of chemical composition, α phase and β phase, as well mechanical state imposed. This flow stress is developed to model the flow behavior of titanium alloys in machining, at speed of higher than 5m/s, characterized by extremely high strains (2∼10 or higher), high strain rates (104∼106s−1 or higher) and high temperatures (600∼1300°C). The flow stress sensitivity to mechanical and material parameters is analyzed. A new SCM-based Johnson-Cook (JC) flow stress model is proposed whose constants and ranges are determined using experimental data and the physical basis for SCM approach from literature. This new flow stress is successfully implemented in the finite element framework to simulate high speed machining process and compared with other types of flow stress models in terms of chip morphology. The predicted results confirm that the new model is much more effective and reliable than the original JC model in predicting chip segmentation in the high speed machining of titanium Ti-6Al-4V alloy.
Energy Mapping and Optimization in Rough Machining of Impellers
Authors: Wu Zhenhua , Hobgood Marthony , Wolf Mathias
Published: September 2016

In this paper, energy mapping and optimization in rough machining of impellers was investigated. Experiments were first designed based on the response surface methodology (RSM) to minimize operation specific energy consumption in machining through selection of machining parameters (spindle speed, cutting depth, and feed rate) in the Siemens NX computer aided manufacturing (CAM) simulation. With the simulated machining solution and G-code, experiments were conducted on the CNC lathe and mill to cut Al 6061 impellers. The machine energy consumption was measured using a power meter. The operation specific energy was analyzed in analysis of variance (ANOVA), regression models, and desirability functions. The minimum specific energy in the rough and semi-finish turning process is 0.16 J/mm3 and 0.23 J/mm3 respectively. The minimum specific energy in the blades milling process with 6mm ball mill or 3mm ball mill is 0.08 J/mm3 and 0.42 J/mm3 respectively. In the experiment settings, it identified that cutting depth is the most critical factor to affect the specific energy consumption in impeller machining. The empirical equations between the specific energy and material removal rate (MRR) concluded that specific energy is proportional to the inverse of MRR. From the study, it would suggest that in order to minimize the specific energy in machining of impellers, it should selected the MRR as large as possible.
One Touch Workpiece Verification System for CNC Machining Using a Low-Cost Computer Vision Approach
Authors: Micali Maxwell K. , Cashdollar Hayley M. , Gima Zachary T. , Westwood Mitchell T.
Published: September 2016

While CNC programmers have powerful tools to develop optimized toolpaths and machining plans, these efforts can be wholly undermined by something as simple as human operator error during fixturing. This project addresses that potential operator error with a computer vision approach to provide coarse, closed-loop control between fixturing and machining processes. Prior to starting the machining cycle, a sensor suite detects the geometry that is currently fixtured using computer vision algorithms and compare this geometry to a CAD reference. If the detected and reference geometries are not similar, the machining cycle will not start, and an alarm will be raised. The outcome of this project is the proof of concept of a low-cost, machine/controller agnostic solution that is applied to CNC milling machines. The Workpiece Verification System (WVS) prototype implemented in this work cost a total of $100 to build, and all of the processing is performed on the self-contained platform. This solution has additional applications beyond milling that the authors are exploring.
Industry 4.0 and Cloud Manufacturing: A Comparative Analysis
Authors: Liu Yongkui , Xu Xun
Published: September 2016

The introduction of the Internet into the manufacturing environment is becoming a prominent trend. In this context, two important concepts concerning manufacturing, i.e. Industry 4.0 and cloud manufacturing have been proposed. Industry 4.0 refers to the fourth industrial revolution and is often understood as the application of Cyber-Physical Systems in industrial production with the help of the Internet to achieve the Internet of Things and the Internet of Services. Meanwhile, the Internet-based new business technology trends, such as cloud, servitization and collaboration, have brought about a novel cloud-based service-oriented manufacturing model — cloud manufacturing. These two concepts, though bearing some similarities, adopt different ideas and approaches for promoting the development of manufacturing industry. Given the great significance of the two concepts to the manufacturing industry, there is a need to understand their similarities and differences. This paper firstly gives a brief up-to-date review of Industry 4.0 and cloud manufacturing, and then clarifies the relationship between them based on the basic concepts and their current research statuses.
Machining of Transparent Brittle Material Assisted by Laser-Induced Seed Cracks
Authors: Shanmugam Naveenkumar , Yu Xiaoming , Alkotami Hazem , Devin Garrick , Lei Shuting
Published: September 2016

Materials such as glass and silicon dioxide have seen increased applications due to their advantageous properties including high strength and corrosion resistance. However, machining these materials are challenging due to their hard and brittle nature. Even though techniques such as abrasive jet machining have improved machining quality, they typically suffer from low productivity and poor surface integrity with subsurface cracks. This study focuses primarily on attaining high quality machined surface free from sub-surface cracks on BK7 samples by inducing microcracks on to the material. The hypothesis is that microcracks induced by femtosecond laser would synergistically assist the material removal process by weakening the material layer to be removed. As the first phase of research, the cracks are initiated starting from the material surface. Results show that machining laser-treated samples leads to on average 75% force reduction in comparison with machining untreated samples. Laser treated machined samples are produced without subsurface damages, and reduced tool wear is also noted.
Springback Evaluation of 304 Stainless Steel in an Electrically Assisted Air Bending Operation
Authors: Khal Abdelrahim , Ruszkiewicz Brandt J. , Mears Laine
Published: September 2016

Driven by the automotive industry’s drive towards lightweighting, electrically assisted forming (EAF) is one of the most rapidly growing research fields in bulk deformation, and is classified under the general term “Electrically-Assisted Manufacturing (EAM)”. In EAF electric current (continuous or intermittent) is applied to a metallic sheet during the forming process, leading to numerous advantageous effects that have been studied and proven by several research groups and for different structural metals, such as reduced forming load and flow stress, increased formability, and reduction (or even elimination) of springback. Electrically-assisted bending (EAB) is a recent evolution of EAF technique, with the aim of capitalizing on the aforementioned advantages of EAF technique. In this work the effects of the EAB process on the final springback in an air bending test are identified, with the metal sheet being bent under different electrical field conditions. In addition, a comparison between the effects of applying the current during forming versus post forming are investigated. It was found that in general, higher current density (amount of current through cross sectional area of specimen (A/mm2), more frequent pulse period, and longer pulse duration all resulted in a greater degree of springback reduction. A microstructural evaluation showed no change in grain size in the presence of electric current.
Investigating a Die Quench Cracking Problem in 52100 Steel Bearing Rings With Computer Simulation
Authors: Reardon Arthur C. , Freborg Andrew , Li Zhichao (Charlie) , Ferguson Lynn
Published: September 2016

Quenching using a press with controlled die loads, commonly referred to as press quenching, is a specialized technique used to minimize distortion of critical components such as gears and high quality bearing races. Improper press load magnitudes or timing of the load application may restrict part movement during quenching to the point of imposing stresses that cause cracking, especially in a common bearing steel such as AISI 52100, high carbon, high strength steel. This paper applies a finite element based heat treat simulation tool, DANTE®, to investigate the sensitivity of cracking to press quenching process parameters.

The typical method for designing a press quench process to control flatness, out-of-round, and taper is by experience coupled with trial-and-error. This is accomplished by adjusting oil flow rates, flow directions, die loads, and the timing of die loads. Metallurgical phase transformations occur during the quenching process as austenite transforms to martensite and possibly to diffusive phases. Thermal contraction due to cooling and volumetric expansion due to the phase changes therefore occur simultaneously during the heat treating process. A constantly changing stress state is present in the part, and improperly applied die loads, oil flow or oil flow rate can add additional stress to result in cracking.

An inconsistent cracking problem in an AISI 52100 bearing ring was evaluated using production trials, but the process statistics were not conclusive in identifying the source of the problem. Heat treatment process modeling using DANTE was used to investigate the effects of quench rate, die load pulsing, and several other process variables to determine how these parameters impact the resulting stresses generated during the press quenching operation.
Intricate Geometric Design and Manufacturing on Vibration-Assisted Needles for Medical Applications
Authors: Cai Yi , Moore Jason , Lee Yuan-Shin
Published: September 2016

This paper presents a unique design of solid surgical needle featured by its 4-plane bevel tip and shaft slots with the aim to further explore the potential of vibratory needle insertion for medical applications. The design philosophy of the needle was introduced. To overcome the challenging issues faced in fabricating the designed needles, a non-traditional manufacturing process using electric discharging machining (EDM) for the tip and slots is presented. Two important parameters for needle cutting edges, the inclination angle and the included angle, were derived from the two fabrication variables of the bevel angle and the interval angle. Needle prototypes of the proposed design were fabricated with different geometries, and they are used to conduct several different experiments. In the first experiment, the needles were inserted into tissue phantom, and the friction slope was chosen as the performance criterion. In the second experiment, the testing medium was skin-mimicking polyurethane sheet, and the puncture force and depth were used to evaluate the performance. In both experiments, different vibration conditions of frequency-amplitude combinations (250Hz-5μm, 250Hz-50μm and 1500Hz-5μm) were applied in terms of frequency and amplitude. The preliminary results showed both weakness and potentials of the proposed design, and indicated the necessity for more experiments. Experiments and results to validate the presented method are also presented. The design and manufacturing techniques presented in this paper can be used for the design and development of surgical needles and cutters for engineering and medical applications.
Managing Complexity in Manufacturing Changeovers: A Sustainable Manufacturing-Oriented Approach and the Application Case Study
Authors: Mustafa Khalid , Cheng Kai
Published: September 2016

Increasing manufacturing complexity continues to be one of the most significant challenges facing the manufacturing industry today. Due to these rapid changes in manufacturing systems, one of the most important factors affecting production is recognized as the frequent production setup or changeovers, consequently affecting the overall production lead times and competitiveness of the company. Developing responsive production setup and process capability is increasingly important as product ranges and varieties in manufacturing companies are growing rapidly and, at the same time, production business models are operating more towards being customer-oriented. Furthermore, although different conventional methods have been used to manage complexity in production changeovers, sustainability and competitiveness development in a manufacturing company needs to be scientifically addressed by managing manufacturing complexity. In this paper, a sustainable manufacturing-oriented approach is presented in mind of managing manufacturing changeover complexities. A case study is carried out specifically concerning changeover complexity in a pharmaceutical company, aiming at minimizing complexities in production changeover and waste, increasing plant flexibility and productivity, and ultimately the sustainable competitiveness of the company in managing manufacturing changes.
Profile Monitoring and Fault Diagnosis via Sensor Fusion for Ultrasonic Welding
Authors: Guo Weihong , Jin Jionghua (Judy) , Hu S. Jack
Published: September 2016

Sensor signals acquired during the manufacturing process contain rich information that can be used to facilitate effective monitoring of operational quality, early detection of system anomalies, quick diagnosis of fault root causes, and intelligent system design and control. This paper develops a method for effective monitoring and diagnosis of multi-sensor heterogeneous profile data based on multilinear discriminant analysis. The proposed method operates directly on the multi-stream profiles and then extracts uncorrelated discriminative features through tensor-to-vector projection, and thus preserving the interrelationship of different sensors. The extracted features are then fed into classifiers to detect faulty operations and recognize fault types. The developed method is demonstrated with both simulated and real data from ultrasonic metal welding.