bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Modeling of Manufacturing Equipment Capability in Cloud Manufacturing
Authors: Yu Jiajia , Zhou Zude , Xu Wenjun
Published: October 2014

In order to efficiently obtain the on-demand services of manufacturing equipment resources in terms of the customers’ requirements, the manufacturing equipment resources together with their capability should be searched and matched during the production processes in Cloud Manufacturing. In this context, the issue of how to realize the dynamic formal description of manufacturing equipment capability becomes a basis to support such manufacturing activities. In this paper, the manufacturing equipment capability was modeled dynamically using OWL (Web Ontology Language), based on the mapping relation which associates manufacturing equipment capability attributes and real-time data. The semantic relationship between concepts in the ontology model can be explicitly and implicitly reflected using the OWL which makes it convenient to discover, share and reuse the manufacturing equipment capability. The effectiveness of the proposed modeling method was validated by a case study, and the results showed that the dynamic modeling method could reflect current state and dynamic capability of manufacturing equipment resources.
Control of Ablation Depth and Surface Structure in P3 Scribing of Thin-Film Solar Cells by a Picosecond Laser
Authors: Zhao Xin , Cao Yunfeng , Nian Qiong , Cheng Gary , Shin Yung C.
Published: October 2014

In this paper, precise P3 scribing of thin-film solar cells (AZO/CIGS/Mo/Glass) via a picosecond laser is investigated. A parametric study is carried out for P3 scribing to study the effects of laser fluence and overlap ratio on ablation depth and slot quality, supported by the numerical prediction using a two-temperature model. The optimum scribing conditions are determined, and the potential processing speed is increased. Laser induced periodic surface structures are also presented after the scribing process, which can potentially enhance the absorption of the cell surface and consequently increase the cell efficiency.
Advanced Five-Plane Lancet Needle Design, Grinding, and Tissue Insertion
Authors: Wang Yancheng , Chen Roland K. , Tai Bruce L. , Shih Albert J.
Published: October 2014

The needle with lancet point (NLP), having three planes at the tip to generate a sharp lancet point, is the most common needle tip geometry. This research presents two five-plane lancet needle designs, the five-plane lancet needle with two back bevels (FLN-B) and five-plane lancet needle with two front bevels (FLN-F), to study the effect of two additional bevel planes on the reduction of soft tissue insertion force over that of the NLP. The mathematical models for inclination and rake angles along the cutting edges, and the grinding procedure and setup parameters for FLN-B and FLN-F are developed. Prototype needles are fabricated and the needle insert test was conducted on PVC phantom tissue which mimics the soft tissue. Compared to NLP, FLN-B and FLN-F have higher inclination and rake angles and can reduce the insertion forces by 9.1% and 8.3%, respectively.
Experimental Investigation of Drilling Incorporated Electrochemical Discharge Machining
Authors: Jiang Baoyang , Lan Shuhuai , Ni Jun
Published: October 2014

Electrochemical discharge machining (ECDM) is a non-conventional micromachining technology, and is highlighted for non-conductive brittle materials. However, the outcomes of ECDM have many restrictions in application due to limitations on efficiency, accuracy, and machining quality. In this paper, a drilling incorporated ECDM process is presented and analyzed to enhance material removal rate in ECDM drilling process. Incorporating micro-drilling into ECDM significantly increases the rate of material removal, especially in deep hole drilling. As fundamentals of the machining process, material removal mechanisms have been investigated to account for the increment in material removal rate by incorporating micro-drilling. Vibration of tool electrode, induced by a piezo-actuator, was introduced to further enhance material removal rate. Quantitative studies were conducted to determine the appropriate process parameters of drilling incorporated ECDM with tool vibration.
An Investigation of the Ring Hoop Tension Test for Anisotropic Tubes
Authors: Dick Christopher P. , Korkolis Yannis P.
Published: October 2014

The ring hoop tension test (RHTT) is investigated experimentally and numerically to determine its validity and limitations in predicting the hoop response of materials in tubular form. Our experiments involved RHT-Testing of Al-6061-T4 tubes. Digital image correlation (DIC) was used to capture the strain evolution in the gage section of the specimens, giving a full-field measurement of the strains. The local hoop stress-strain response of the material was assessed in this way. Finite element analysis was used to further investigate the effects of friction, eccentricity and contact pressure on the recorded response. Friction was found to have a negligible effect on the recorded response for friction coefficient values of 0.01 and lower. However, it was found that larger values of friction may render the test meaningless. Tube eccentricity of the magnitude present in the tubes tested here (±4% of the nominal thickness) was determined to have no effect on the material response. It was also determined that tubes should not be turned to a uniform thickness as this may induce machining damage and release the existing residual stresses, thus causing error in determining the tube response in the hoop direction. The contact pressure was found to not significantly affect the state of uniaxial tension in the specimen and thus to have a negligible effect on the material response. By comparing the hoop with the axial response, the material anisotropy of the Al-6061-T4 tubes was established.
Friction Stir Blind Riveting for Dissimilar Cast MG AM60 and Al Alloy Sheets
Authors: Min Junying , Li Jingjing , Wang Weiming , Carlson Blair E. , Li Yongqiang , Quinn James F. , Lin Jianping
Published: October 2014

A new one-sided joining method, friction stirring blind riveting (FSBR) was successfully implemented to form lap-shear joints for dissimilar metals from pairs of 3.05mm thick cast Mg AM60, rolled 1.5mm thick Al AA6022 and extruded 3.15mm thick Al AA6082 specimens. The concept of this process is riveting the two workpieces with reduced force under frictional heat and fastening the workpieces through blind riveting once the rivet is fully inserted. In this research the process was experimentally analyzed and optimized for four joint combinations. It was demonstrated that switching the positions of Mg and Al alloy specimens has a significant effect on the process window and maximum tensile load of the joints. Three quality issues of the FSBR joints were observed and discussed. The mechanisms associated with joint strength were discussed and explain the effects of FSBR process, material matching and sheet position on the joint tensile strength.
A Low-Cost and High-Resolution Micro Machine Tool With Toggle-Based Mechanism
Authors: Wang Shih-Ming , Yang Chih-Peng , Ye Zhe-Zhi , Yen Chuntai
Published: October 2014

The products of 3C, bioscience, medical industry, and aerospace industry are becoming smaller and smaller. The components of the products are made of various materials with complex 3D shapes requiring high accuracy in their dimensions and contours. An accurate micro-/meso-scale CNC machine tool is an essential part of this technology. A new type of CNC micro machine tool with a toggle-like mechanism having the characteristics of low-cost and fine-resolution was developed. With geometric reduction principle, the machine can provide finer feed resolution and better positioning accuracy without using high-end driving components and controller. The kinematics model and characteristics of the machine were derived and analyzed. Modal analysis and dynamic compliance analysis were employed to design a light-weight structure with good stiffness. The accuracy calibration results showed the machine can reach a positioning accuracy of 500 nm. Prototype of the machine was built, and furthermore some micro machining examples were demonstrated in this paper.
Review on the Development of Non-Destructive Testing Based on Laser Ultrasonic Technique
Authors: He Yuanfeng , Zhang Wenwu
Published: October 2014

Development of industry demands better performance of equipments and devices than ever. The property of material used to produce the equipments is the precondition to ensure the quality. As equipments are usually required to be integral during the quality inspection, non-destructive testing (NDT) plays an increasingly import role in modern industry quality control. Different NDT methods are introduced and analyzed. The mechanism of ultrasonic exciting is described. After the ultrasonic is excited, the vibration signal can be detected by transducer or optical method which are then illustrated. In the section of development of laser ultrasonic technology, contributions made by various researchers in theoretic development, experiment, simulation and application are introduced and the corresponding content of the researches as well. The conclusion and the outlook of laser ultrasonic technique is made at the last.
Fabrication and Tribological Functions of Micro Dent Arrays on Ti-6Al-4V Surface by Laser Shock Peening
Authors: Caslaru R. , Guo Y. B. , Wei X. T.
Published: October 2014

Surface patterning has become a valuable technique for fabricating micro dents which may act as lubricant reservoirs to reduce friction and wear in sliding and rolling contact applications. In this paper, the use of laser shock peening (LSP) along with an automatic X-Y table proves to be an attractive and reliable method for producing micro dent arrays with enhanced surface integrity. Surface topography and profiles of the fabricated micro dent arrays on polished Ti-6Al-4V have been characterized. The effect of dent arrays with different density on friction reduction at low and high viscosity lubrication was investigated. An acoustic emission (AE) sensor was used to on-line monitor friction and wear processes. It was found that a surface with 10% dent density provides better effect in reducing coefficient of friction (CoF) than those of smooth surface and a surface with 20% dent density. It was shown that there is a strong correlation between acoustic emissions (AE) signals, especial AE cumulative counts and wear rate.
Joint Production and Energy Modeling of Sustainable Manufacturing Systems: Challenges and Methods
Authors: Wang Yong , Li Lin
Published: October 2014

This paper proposes a framework for addressing challenges of joint production and energy modeling of sustainable manufacturing systems. The knowledge generated is used to improve the technological readiness of manufacturing enterprises for the transition towards sustainable manufacturing. Detailed research tasks of the framework are on the modeling of production, energy efficiency, electricity demand, cost, and demand response decision making. Specifically, the dynamics and performance measures of general manufacturing systems with multiple machines and buffers are modeled to integrate energy use into system modeling. The expressions of electrical energy efficiency and cost are then established based on the electricity pricing profile. Finally, joint production and energy scheduling problem formulations and the solution technique are discussed. New insights are acquired based on the applications of the established model in system parameter selection, rate plan switching decision making, and demand response scheduling. Appropriate implementation of this research outcome may lead to energy-efficient, demand-responsive, and cost-effective operations and thus improve the sustainability of modern manufacturing systems.
Experimental Estimation of Size Effect and Formability in Microscale Deep Drawing Process Using Copper Sheet
Authors: Nam Jung Soo , Lee Sang Won , Kim Hong Seok
Published: October 2014

In this study, the size dependence of metal sheet on the plastic deformation behavior was investigated in microscale deep drawing process. In order to perform deep drawing experiments, a tooling system was first developed. Then, a series of microscale deep drawing experiments were performed in various process conditions. The blank holder gap between the blank and blankholder was controlled to eliminate the possible defect such as wrinkling. In particular, the effects of feature size were analyzed by comparing the normalized deformation loads at different values of the scale factor λ. It was found that the maximum value of the normalized deformation load and the failure instant were strongly influenced by the feature size of metal sheet.
Experimental Observation for Surface Modification of Metal Plates Using Continuous Electron Beam Polishing (CEBP)
Authors: Kim JiSoo , Park Hyung Wook
Published: October 2014

The finish process is the most important to determine the quality of the products. In this study, the surface modification of metal plates using the continuous electron beam has been adopted as the final process. The general materials such as SM20C, SUS303 and Al6061 were selected to evaluate the performance of the finishing process using the continuous electron beam. Surface modifications have been carried out with respect to various conditions. Based on the analysis of changing surface properties, the optimal conditions were extracted to obtain the smooth surface. The change in microstructure after irradiation was observed to identify the metallurgical variation within the thin re-solidification layer of these targeting materials. In addition, the changes of surface contact angle and surface hardness after and before irradiation were analyzed.
Partial Encryption Based Secure Sharing of CAD Models for Cloud-Based Design
Authors: Cai Xiantao , Li Weidong , He Fazhi
Published: October 2014

Model security for collaborative product design in a networked environment (or called networked manufacture, grid manufacture, and cloud manufacture) is an important but also challenging research issue. In order to support collaborative product design in a secure and flexible means, a partial encryption based secure sharing method for Computer Aided Design (CAD) model is presented in this paper. Based on the above method, parts of a CAD model can be selected flexibly by users for encrypting according to different users’ requirements. The secret keys for the different parts of the CAD model can be customized to meet the requirements of users. Case studies have been developed to demonstrate the effectiveness of the proposed method.
A Cloud Based Feature Recognition System to Support Collaborative and Adaptive Process Planning
Authors: Anbalagan Arivazhagan , Wang Sheng , Weidong Li
Published: October 2014

This paper presents a Cloud Based Feature Recognition Module (CB-FRM) developed to support Collaborative and Adaptive Process Planning for Sustainable Manufacturing Environments. In the work, the CB-FRM is developed for a Cloud-based environment and based on an innovative ‘pattern-strings’ feature recognition concept. The Cloud system is designed in a light client and heavy server architecture, where the ‘pattern-strings’-based feature recognition approach is developed and deployed. Through recognized ‘pattern-strings’, the feature recognition process is able to extract the complete information of features with its location in the plane. The detailed information of the features is then shared in a developed Cloud environment for the downstream process planning activities. The implementation aspect is explained with the help of a sample industrial part by emphasizing the importance of Cloud manufacturing environment with process planning activities.
Fully Resolved Numerical Simulations of Fused Deposition Modeling
Authors: Dabiri Sadegh , Schmid Steven , Tryggvason Gretar
Published: October 2014

Fully resolved numerical simulations of the deposition of a filament of hot, viscous liquid, and its solidification, are presented. The computations are done using a front tracking/finite volume code designed for direct numerical simulations of multiphase flows, but here we add a volume source that follows a prescribed trajectory to inject the melt. The cooling of the melt is simulated and once it is cool enough the melt is solidified. The result suggest that the deposition is fully captured and that remelting of already solidified material results in a compaction of the deposited filaments.
A Smart Cloud-Based System for the WEEE Recovery/Recycling
Authors: Wang Xi Vincent , Lopez N. Brenda N. , Wang Lihui , Li Jinhui , Ijomah Winifred
Published: October 2014

Waste Electrical and Electronic Equipment (WEEE) is both valuable and harmful since it contains a large number of profitable and hazardous materials and elements at the same time. At component level, many parts of the discarded equipment are still functional and recoverable. Thus it is necessary to develop a distributed and intelligent system to support WEEE recovery and recycling. In recent years, the Cloud concept has gained increasing popularity since it provides a service-oriented architecture that integrates various resources over the network. Cloud Manufacturing systems are proposed world-wide to support operational manufacturing processes. In this research, Cloud Manufacturing is further extended to the WEEE recovery and recycling context. A Cloud-based WEEE Recovery system is developed to provide modularized recovery services on the Cloud. A data management system is developed as well, which maintains the knowledge throughout the product lifecycle. A product tracking mechanism is also proposed with the help of the Quick Respond code method.
Characterization of Fiber Pull-Outs in Drilled CFRP Holes Using Confocal Laser Microscope
Authors: Wang Xin , Kwon Patrick , Pelikhatyy Ruslan , Kim Dave (Dae-Wook)
Published: October 2014

Carbon Fiber Reinforced Plastic (CFRP) material is often drilled when constructing a large aircraft structure. When drilling CFRP, many defects can be left on the CFRP hole surface. One of the most detrimental surface defects is known as fiber pull-outs, which occur when bundles of fibers are pulled away by fiber-matrix de-bonding and matrix stripping. The objective of this research is to use confocal laser scanning microscope (CLSM) in order to characterize fiber pull-outs occurred during the drilling process of quasi-isotropic CFRP. This new optical characterization method is capable of measuring maximum depth and the distributions of fiber pull-outs. Fiber pull-outs are also qualitatively characterized by SEM and CLSM. It is found that the average depth of fiber pull-outs acquired from CLSM is approximately two times larger than those from the surface profilometer. However, there is a proportional correlation of the data between CLSM and surface profilometer.
The Root Cause of Nose and Flank Wear and Their Behavior in Turning Ti-6Al-4V With Carbides and PCD Inserts
Authors: Nguyen Trung , Kwon Patrick , Kang D. , Bieler Tom
Published: October 2014

This paper addresses the root cause for flank and nose wear when machining Ti alloys. In machining ferrous metals, at least the cementite (Fe3C) phase is present as the abrasive contributing to the flank wear. However, most titanium alloys possesses no significant hard phase, which questions the root cause for those wear. In this study, a Ti-6Al-4V bar was turned under various conditions with few grades of uncoated carbide and PCD-insert type tools. The cutting tools were retrieved sporadically after stopping the tuning process in order to examine the wear patterns and their evolution on the tools. The nose and flank wear patterns on the tool inserts were investigated with a confocal microscope. The microstructure of the bar was characterized using Orientation Image Microscope with Electron-Backscattered Diffraction Scan (EBDS). Two distinct types of damages were identified, (a) Micro-fracture at the cutting edge and (b) Scoring markings. Based on the microstructure and the tool wear patterns, this paper claims that both types of damages were caused primarily by the hard orientation of the alpha (α or Hexagonal Closed Packed) crystalline phases and secondarily by the adhesion layer detaching parts of the tool material from the nose and flank surfaces.
Vaporizing Foil Actuator Welding of AA6061 With Cu110: Effect of Heat Treatment Cycles on Mechanical Properties and Microstructure
Authors: Vivek Anupam , Hansen Steven R. , Liu Bert C. , Daehn Glenn S.
Published: October 2014

This work aims to study the effect of microstructure of the weld between aluminum alloy AA6061 and commercially pure copper, Cu 110, on its mechanical properties. AA6061-T6 and T4 aluminum sheets of 1 mm thickness were launched towards copper targets using the Vaporizing Foil Actuator (VFA) tool operating at 8 kJ input energy level. Flyer plate velocities, measured via photonic Doppler velocimetry (PDV), were observed to be approximately 800 m/s. All the welded samples were subjected to instrumented peel testing, microhardness testing, energy-dispersive x-ray spectroscopy (EDS), and SEM. The welded joints had cracks which ran through the continuous intermetallic layers and stopped upon encountering a ductile metallic wave. The welds created with T6 temper flyer sheets were found to have smaller regions with wavy interfaces free of intermetallics as compared to those created with T4 temper flyer sheets. Peel strength tests of the two types of welds resulted in failure along the interface in case of the T6 flyer welds, while the failure generally occurred in the parent aluminum in the case of the T4 flyer welds. Half of the T4 flyer welds were subjected to aging for 18 hours at 160 °C to convert the aluminum sheet back to T6 condition. Although the flyer material did not attain the hardness of the original T6 material, it was found to be significantly stronger than the T4 material. These welds retained their strengths after the aging process and diffusion across the interface was insignificant.
Multi-Scale Surface Characterization and Control Based High Density Measurements
Authors: Weng Xin , Jin Xiaoning , Ni Jun
Published: October 2014

It is widely observed that today’s engineering products demand increasingly strict tolerances. The shape of a machined surface plays a critical role to the desired functionality of a product. Even a small error can be the difference between a successful product launch and a major delay. Thus, it is important to develop measurement tools to ensure the quality and accuracy of products’ machined surfaces. The key to assessing the quality is robust measurement and inspection techniques combined with advanced analysis. However, conventional Geometrical Dimensioning and Tolerancing (GD&T) such as flatness falls short of characterizing the surface shape. With the advancements in metrology methodology utilizing digital holographic interferometry, large amount of surface data can be captured at high resolution and accuracy without changing platform or technique. This captured High Definition Data (HDD) enables the mining of more valuable information from machined surfaces that most current industry practice cannot achieve in a timely manner. Such new metrology system opens the torrent of observable events at plant floor and increases the transparency of machining processes. This presents great opportunities to characterize machined surface into a new level of details, which can be applied in production quality evaluation and process condition monitoring and control. This research work proposes a framework of a multi-scale surface characterization for surface quality evaluation and process monitoring. Case studies are presented to show how proposed metrics could be applied in surface quality evaluation and process monitoring.
Vaporizing Foil Actuator: Controlling the Pressure Pulse for Impulse Metalworking
Authors: Hansen Steven R. , Vivek Anupam , Daehn Glenn S.
Published: October 2014

Electrically-driven rapid vaporization of thin conductors produces a high-pressure pulse which can be used to accelerate thin metal sheets to high velocities. Recently, vaporizing foil actuators (VFA) have been applied toward a variety of impulse-based metalworking operations such as collision welding, closed-die forming, embossing, and shearing. To better apply VFA to different purposes, it is necessary to develop an understanding of how variations in the characteristics of the foil actuator affect its mechanical impulse generation. In this work, actuators made out of 0.0508, 0.0762, and 0.127 mm thick full hard temper AA1145 foil were used to launch 0.508 mm thick AA2024-T3 sheets toward a photonic Doppler velocimeter (PDV) probe. Launch velocities ranging between 300 and 1000 m/s were observed over a distance of less than 3 mm, and repeated trials demonstrated repeatable results. Velocity, current and voltage traces were used to examine the effect of deposited energy on average pressure and resulting velocity for foil actuators of various thicknesses. Experiments with annealed foil actuators showed that foil temper had no effect on the evolution of flyer velocity for the given electrical energy input of 8 kJ.
Single Point Diamond Turning of Silicon by Using Micro-Laser Assisted Machining Technique
Authors: Mohammadi Hossein , Poyraz H. Bogac , Ravindra Deepak , Patten John A.
Published: October 2014

In this study, single point diamond turning (SPDT) is coupled with the micro-laser assisted machining (μ-LAM) technique. The μ-LAM system is used to preferentially heat and thermally soften the work piece material in contact with a diamond cutting tool. In μ-LAM the laser and cutting tool are integrated into a single package, i.e. the laser energy is delivered by a single mode fiber laser to and through a diamond cutting tool. This hybrid method can potentially increase the critical depth of cut (DoC), i.e., a larger ductile-to-brittle transition (DBT) depth, in ductile regime machining, resulting in a higher material removal rate (MRR). An IR continuous wave (CW) fiber laser, wavelength of 1064nm and max power of 100W with a beam diameter of 10μm, is used in this investigation. In the current study SPDT tests were employed on single crystal silicon (Si) wafer which is very brittle and hard to machine by conventional methods. Different outputs such as surface roughness and depth of cut for different set of experiments were analyzed. Results show that an unpolished surface of a Si wafer can be machined in one pass to get a very good surface finish. The Ra was brought down from 1.2μm to 275nm only in one pass which is a very promising result for machining the Si wafer.
Multi-Material Capability of Laser Induced Plasma Micromachining
Authors: Saxena Ishan , Ehmann Kornel
Published: October 2014

Presently surface micro-texturing has found many promising applications in the fields of tribology, bio-medical engineering, metal cutting, and other functional or topographical surfaces. Most of these applications are material-specific, which necessitates the need for a texturing and machining process that surpasses the limitations posed by a certain class of materials that are difficult to process by laser ablation, owing to their optical or other surface or bulk characteristics. Laser Induced Plasma Micromachining (LIPMM) has emerged as a promising alternative to direct laser ablation for micro-machining and micro-texturing, which offers superior machining characteristics while preserving the resolution, accuracy and tool-less nature of laser ablation. This study is aimed at understanding the capability of LIPMM process to address some of the issues faced by pulsed laser ablation in material processing. This paper experimentally demonstrates machining of optically transmissive, reflective and rough surface materials using LIPMM. Apart from this, the study includes machining of conventional metals (Nickel and Titanium) and polymer (Polyimide), to demonstrate higher obtainable depth and reduced heat affected distortion around micro-features machined by LIPMM, as compared to laser ablation.
Automatic Detection of Directions of Dimensional Control in Mechanical Parts
Authors: Mohan Prashant , Haghighi Payam , Shah Jami J. , Davidson Joseph K.
Published: October 2014

This research is part of a larger project which aims at developing a tool to help designers create effective GD&T schemas. The first step towards this goal is to determine the particular directions in which dimensions and tolerances need to be controlled. These directions we label here as “Directions of (Dimensional) Control” or DoC for short. Regardless of whether one uses chain dimensioning, reference dimensioning or geometric tolerancing, all size and basic dimensions of position line up in a finite number of directions or Directions of Control. This paper presents an approach for automatically identifying the directions of control from CAD models of mechanical parts. The only input to the system is the geometry of parts or assemblies in STEP file format. The analysis is done part by part for an assembly. First, planar and cylindrical features are recognized and their normal/axes extracted. The extracted features are then organized into groups of parallel normal or axes directions. Cylindrical features can belong to two or more Directions of Control, while planar features belong can only belong to one. Features in each DoC are then ordered based on perpendicular relative distances. Each ordered feature list forms a linear chain in which nodes represent features and links are attributed with relative distance to the nearest neighbors on each side. DoC chains are related to each other by relative orientation. Therefore, the chains are combined into a unified graph, using the junction nodes to contain the relative orientation between the chains. The extracted Directions of Control can be output in both textual and graphical form. Although the primary motivation for automatic DoC graph generation is computer assisted tolerancing and automatic tolerance analysis, the paper also discusses other applications in manufacturing.
On the Manufacture of Lightweight Alloy Tubes via Friction Stir Back Extrusion: Process Evaluation and Material Performance
Authors: Milner Justin L. , Abu-Farha Fadi
Published: October 2014

A new manufacturing approach in which the friction stirring phenomenon is used as a vehicle for facilitating the deformation of bulk lightweight materials into manufactured components has been recently introduced under the general concept of “bulk friction stir forming”. In a preliminary work, the concept was applied to the back extrusion process, in what was referred to as “friction stir back extrusion” or FSBE; it was shown that the concept is practically valid and FSBE is capable of producing lightweight tubular specimens. Nevertheless, the FSBE process was claimed to have several merits over conventional processes, mainly: (i) unique process capabilities and energy efficiency (ii) significant grain refinement, and thus (iii) favorable mechanical properties in the formed tubes. None of these claims were adequately addressed nor quantified in earlier work. Therefore, this work presents a comprehensive study that aims to reveal the true merits of FSBE, validate the claims, and quantify its effects on the microstructure and mechanical properties of the deformed material. The outcomes of the study are presented in three major parts, each addressing one of the abovementioned claims. Force, torque and power measurements during FSBE experiments are used to address the first claim. Detailed optical microscopy and electron back scatter diffraction work is carried out in the second part to quantify the changes to the grain structure and texture of the material. Finally, the third part presents detailed mechanical characterization using digital image correlation to quantify the effects of FSBE on the performance of the produced tubes.
Investigation of Trochoidal Milling in Nickel-Based Superalloy Inconel 738 and Comparison With End Milling
Authors: Pleta Abram , Ulutan Durul , Mears Laine
Published: October 2014

Nickel-based superalloys are designed for use in extreme environments and are getting progressively better for these environments, therefore much harder to machine. They play a crucial role in elevated temperature applications where high strength, high resistance to corrosion and creep resistance are required. Machinability suffers as a result of these properties and harsh machining conditions occur, resulting in high cutting forces and tool wear. To combat the difficulties in the machining of nickel-based superalloys, such as poor thermal diffusivity and high levels of abrasive wear, trochoidal milling was introduced as an alternative method of milling. This method of milling combines linear motion with uniform circular motion, reducing chip load in exchange for increased machining time. Industry is averse to its widespread adoption due to increasing cycle times when compared to conventional milling methods, however it has been shown that overall productivity can be improved due to less tool wear with a more predictable behavior. This work characterizes the effects of trochoidal milling and provides a comparison of trochoidal milling with a traditional milling technique, end milling, for the machining of Inconel 738. In order to compare the trochoidal and conventional machining approaches directly, metrics of productivity normalized to tool wear are introduced. The normalized metrics introduced in this study aim to provide a more representative comparison of productivity and efficiency characteristics: volumetric material removal per unit tool wear (MR/VB) and the material removal rate per unit tool wear (MRR/VB). It was found that significantly higher volumetric material removal is possible using trochoidal milling, and fewer tools are needed; material removal rates that competitive with end milling can be achieved. When the amount of time spent on tool change for the same volume of material removal is considered, material removal rate of trochoidal milling can even be higher than end milling, indicating that better productivity and efficiency of the process is possible at reduced tooling costs.
Cloud-Based Prognosis: Perspective and Challenge
Authors: Yang Yunjie , Gao Robert X. , Fan Zhaoyan , Wang Jinjiang , Wang Lihui
Published: October 2014

Comprehensive acquisition, distribution, and utilization of information about machine equipment and/or processes across spatial boundaries for improved productivity and decision have increasingly become the hallmark of advanced manufacturing. The emergence of cloud computing has created ample opportunities to achieve this goal. This paper presents a review of the state-of-the-art of prognosis technique for manufacturing and its future development motivated by the cloud infrastructure. Prevailing methods of prognosis are summarized, and their respective performance is comparatively evaluated. Basic principles and recent advances in cloud computing, as well as its application to cloud manufacturing, are introduced. Based on the survey, the concept of cloud-based prognosis is proposed, and its architecture as well as associated challenges are discussed.
Analysis of Debris Motion in Vibration Assisted Reverse Micro Electrical Discharge Machining
Authors: Mastud Sachin A. , Kothari Naman S. , Singh Ramesh K. , Samuel Johnson , Joshi Suhas S.
Published: October 2014

The reverse micro EDM (R-MEDM) has emerged as an important process for machining of high aspect ratio arrayed features and textured surfaces. In R-MEDM process, accumulation of debris particles in the inter-electrode gap drives the process towards instability and also the sticking of debris particles on machined microrod increases its surface roughness. Vibration assisted R-MEDM can help to overcome the issues of debris accumulation, produce debris free surfaces and enabled a creation of textured/engineered surfaces. The objective of this paper is to quantify the debris size distribution, number of debris particles generated per discharge and further simulate the debris and dielectric flow under the influence of electrode vibrations in R-MEDM process. Debris particles of estimated sizes, numbers and ejection velocity are injected into channel and simulated under the influence of electrode vibrations. Simulation results show that the electrode vibrations impart oscillatory motion to dielectric fluid and debris particles. During upward motion of plate electrode, dielectric fluid is pushed out of inter-electrode gap while the flow reversal takes place in the inter-electrode gap when plate electrode starts to move in the downward direction. The debris particles also show similar reciprocating motion whereas such motion of debris is completely absent in a fixed inter-electrode gap (no electrode vibration) condition. It is found that displacement of the plate electrode from bottom to middle position (at 6 kHz frequency and 1 μm amplitude) resulted in 6.4 and 3.4 time increase in maximum dielectric velocity and average velocity of debris particles in particular. The flow reversal and the reciprocating motion improves the overall process stability of R-MEDM process.
Laser Micro Processing of Carbide Tool Insert
Authors: Khan Ashfaq , Khan Muhammad Alam Zaib , Shah Kamran , Khan Aftab , Khan Mushtaq , Imran Syed Husain , Sheikh Mohammad A. , Li Lin
Published: October 2014

For a number of applications there is evidence that the tribological conditions for mating surfaces can be improved by surface texturing. Literature shows that texturing the tool rake face can have a positive influence on tribological properties. This research focuses of the texturing of tool rake surface by laser machining. Compared to other texturing techniques, laser provides the flexibility of machining customized textures on tool surface. This paper deals with the assessment and optimization of the process parameters for generation of textures on cemented carbide inserts under ambient conditions by using a femtosecond laser. The paper is a significant contribution to the efficient and rapid generation of customized surface texture on hard tool inserts.
Wedge Radius Effects in Mechanical Exfoliation of HOPG: A Molecular Simulation Study
Authors: Jayasena B. , Subbiah S. , Reddy C. D.
Published: October 2014

We study the effects of wedge bluntness in mechanically exfoliating graphene layers from highly ordered pyrolytic graphite (HOPG), a layered material. Molecular dynamics simulations show that the layer initiation modes strongly depend on the wedge radius. Force and specific energy signatures are also markedly affected by the radius. Cleaving with a larger wedge radius causes buckling ahead of the wedge; larger the radius more the buckling. A critical depth of insertion of 1.6 A° is seen necessary to cleave a single layer; this is also found to be independent of wedge radius. Hence, with accurate positioning on an atomically flat HOPG surface it is possible to mechanically cleave, using a wedge, a single sheet of graphene even with a blunt wedge.
Effect of Length Scales on Microstructure Evolution During Severe Shear Deformation
Authors: Basu Saurabh , Shankar M. Ravi
Published: October 2014

Effect of length scales on microstructure evolution during Severe Plastic Deformation (SPD) was studied using orthogonal machining as a test of microstructure response. Machining was performed on Ni-200 in the plane strain configuration inside the chamber of a scanning electron microscope. Mechanics of material flow in the deformation zone was characterized in-situ using Digital Image Correlation. Post-mortem Orientation Image Mapping was performed using Electron Back Scattered Diffraction on partially detached chip specimens. Length scales were varied by setting depths of cut between 10-1 μm. It was found that with shrinking length scales, the continuous evolution of microstructure induced by SPD is replaced by abrupt but sporadic refinement mechanisms. By machining pre-strained samples, it was seen that this switchover is further instigated by initial defect concentrations.
Laser Assisted Cold Bending of High Strength Steels
Authors: Liverani Erica , Ascari Alessandro , Fortunato Alessandro , Lutey Adrian
Published: October 2014

This paper presents the feasibility of an innovative application of laser-assisted bending process. The high strength steel sheets bending, carried out after a laser heat treatment, is studied. Several strategies aimed at obtaining a ductile structure along the bending line, suitable for cold forming, are investigated. The influence of laser processing parameters on the microstructure, hardness and strength of the sheets are discussed and analyzed. In order to predict the temperature and ensure the repeatability and reliability of the process, a model for heat treatment simulation is developed. The study of the experimental data and the integration with the simulation of the heating phase lead to the definition of specific process parameters suitable for achieving a crack-free cold bending of high strength steels.
A Unified Approach to Modeling Material Behavior and Microstructure Evolution in Machining of OFHC Copper
Authors: Liu Rui , Salahshoor Meisam , Melkote Shreyes N. , Subramaniam Jayanti , Marusich Troy
Published: October 2014

At a fundamental level, the thermo-mechanical response of metals in dynamic deformation processes such as machining is governed by dislocation processes and associated microstructure evolution. However, the most commonly used material constitutive models in machining are phenomenological (e.g. Johnson-Cook) or semi-phenomenological (e.g. Zerilli-Armstrong) and do not explicitly account for the dependence of material flow stress on dislocation and microstructure evolution processes in a unified manner. The fidelity of machining simulation models is dependent on the amount of micro-scale physics captured in the development of the material constitutive law, microstructure evolution law(s), and the unifying scheme integrating microstructure evolution into the constitutive law. This paper presents a unified material modeling approach that explicitly accounts for dislocation and microstructure evolution processes underlying the finite deformation process. The corresponding evolution laws are formulated and integrated into the constitutive model, which is derived from thermal activation theory and is an additive decomposition of athermal and thermal components of flow stress representing the effects of long-range and short-range obstacles to dislocation motion, respectively. The unified scheme is implemented as a user-defined subroutine in the AdvantEdge™ software (Third Wave Systems LLC) and used to simulate the orthogonal cutting of OFHC copper.
Multiobjective Optimization of End Milling HCHCr Using AlCrN PVD Coated Cutters With MOGA and RSMO
Authors: Biradar Shantisagar K. , Lathkar Geeta S.
Published: October 2014

Here the End milling is studied for optimization of responses such as surface roughness and tool wear while machining HCHCr. These two conflicting responses decide the quality of process; therefore the multiobjective optimization technique is used. The Response Surface Optimizer (RSMO) and Multiobjective Genetic Algorithm (MOGA) were used as the multiobjective optimization techniques. The PVD coating of 2.5 micron AlCrN was used on four flute HSS End milling cutter. Input machining parameters were cutting speed, feed rate, depth of cut and percentage concentration of the solid lubricant MoS2 mixed with SAE-20 base oil. The experimentation was carried out using two level full factorial design concept while ANOVA technique has been used to verify the adequacy of mathematical model. It was found that the cutting speed (V) is having most dominant role on surface roughness and tool wear. The sensitivity analysis was carried out for studying sensitivity of input parameters for the responses.
Supersonic Laser Deposition of Tungsten
Authors: Jones Marshall , Cockburn Andrew , Sparkes Martin , O’Niell William , Lupoi Rocco
Published: October 2014

Near fully dense tungsten coatings onto molybdenum substrates have been demonstrated using the Supersonic Laser Deposition (SLD) process. This is a characteristic that is not readily achievable with refractory materials. The tensile strength of the tungsten deposited coatings is similar to that of wrought tungsten, with no evidence of melting or substrate grain growth. The tungsten coating to a molybdenum substrate shows no evidence of melting or substrate grain growth. The SLD process is a novel deposition method that is based upon Cold Spay (CS) principles. In this technique the deposition velocities can be significantly lower than those required for effective bonding in CS processing. The addition of laser heating alters the mechanical properties of the materials at the deposition site. The results have shown that SLD is able to deposit tungsten with unique interface bonding and desirable properties as opposed to other deposition processes for refractory materials.
Extrusion of Multi-Material Components
Authors: Ben Khalifa Nooman , Foydl Annika , Pietzka Daniel , Jäger Andreas , Tekkaya A. Erman
Published: October 2014

Three innovative extrusion processes for the manufacture of multi-material parts are discussed: co-extrusion of discontinuously steel reinforced aluminum profiles, composite extrusion of continuously steel wire reinforced profiles and composite rod extrusion. In the first two processes the embedded steel elements are not deformable while by composite rod extrusion both materials are deformable. By means of experimental and numerical analysis, the parameters that mainly influence the reinforcement ratio, the extrusion force as well as the material distribution are analyzed. On the basis of this, analytical approaches are deduced to describe the process limits for the technologies. The paper closes with examples of applications regarding the lightweight requirements as well as functional integrations by forming multi-materials.
The Investigation of Energy Loss in Conformal Contact Mechanics of Carpal-Radial Components in Wrist Arthroplasty
Authors: Hodaei Mohammad , Farhang Kambiz
Published: October 2014

The contact mechanics of Wrist prosthetic implant is considered in which the surface roughness of the implant is included. Total wrist replacements are developed to perform wrist function as near normal as possible. The main goal of wrist replacement surgery is to relieve patients from painful arthritis and to maintain function in the wrist and hand. The gradual wearing away of the cartilage covering on bones can lead to the most common form of arthritis, usually osteoarthritis. Wear is a very important issue in wrist implant. Metal debris caused by excessive wear in wrist implant can lead to toxicity and patient discomfort. Since implant wear can be the result of contact between surfaces of Carpal and Radial components, so the investigation of the effect of roughness between wrist components and establishing a model for interaction of surface roughness is very important. There are several different designs of wrist implant. Most of them have two components that are made of metal. A high quality plastic called polyethylene is used as a space between the two components. The purpose of this paper is to investigate the effect of roughness between interaction of these metal and polyethylene in wrist implants. This paper develops a contact model to treat the interaction of Carpal - Radial Components. The contact model describes the interaction of implant rough surfaces including both elastic and plastic deformations. In the model, surfaces are investigated as macroscopically conforming semi-Cylinder containing micron-scale roughness. The derived equations relate contact force on the implant and the minimum mean surface separation of the rough surfaces. Based on the distribution of asperity heights, the force is expressed using statistical integral function of asperity heights over the possible region of interaction of the roughness of the implant surfaces. Closed-form approximate equation relating contact force and minimum separation is used to obtain energy loss per cycle in a load-unload sequence applied to the implant.