bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Integrity of End Milled Ti-6Al-4V Using the TiAlN Coated Tool
Authors: Guo Y. B. , Sun Jie
Published: July 2009

End milling titanium Ti-6Al-4V has wide applications in aerospace, biomedical, and chemical industries. However, milling induced surface integrity has received little attention. In this study, a series of end milling experiment were conducted to comprehensively characterize surface integrity at various milling conditions. The experimental results have shown that the milled surface shows the anisotropic nature with a surface roughness range in 0.6 μm–1.2 μm. Surface roughness increases with feed and radial depth-of-cut (DoC), but varies with the cutting speed range. Compressive residual normal stress occurs in both cutting and feed directions, while the influences of cutting speed and feed on residual stress trend are quit different. The microstructure analysis shows that β phase becomes much smaller and severely deformed in the very near surface with the cutting speed. The milled surfaces are at least 60% harder than the bulk material in the subsurface.
Fabrication of Metallic Stamp With 30 nm Hole Array Using UV Nanoimprinting and Nanoelectroforming
Authors: Han Jeongwon , Yang Jungmo , Lee Byung Soo William , Kang Shinill
Published: July 2009

With increasing demands for products with nano scale patterns manufactured by nanoreplication processes such as nanoinjection molding, nanoimprinting, and etc, fabrication of molds or stamps with nano patterns has become a priority for successful manufacturing of nano patterned products. In this study, a metallic stamp with nano hole array pattern was fabricated by ultra-violet (UV) nanoimprinting process and nanoelectroforming process. For the fabrication of the original silicon master, electron-beam (E-beam) lithography and inductively coupled plasma (ICP) etching process were used. Polymeric nano pillar array pattern, called polymeric master, was replicated from the original silicon master by UV nanoimprinting process. For the successful demolding during UV nanoimprinting process, self assembled monolayer (SAM) of fluoroctatrichlorosilane (CF3(CH2)8SiCl3) was deposited on the original silicon master. With this approach, the expensive silicon master could be reused many times as a master mold. Nickel seed layer as conductive layer was deposited onto the polymeric master using sputtering process. Nanoelectroforming process using nickel sulfamate solution (Ni(NH2SO3)2·4H2O) was carried out to fabricate the metallic nano stamp. Metallic nano stamp which has hole array pattern with diameter of 30 nm and pitch of 50 nm was successfully fabricated by the proposed method. Nanoinjection molding of 30 nm pillar array pattern as a nano data storage media using the present metallic stamp is the subject of ongoing research.
Study of the Dynamic Crack Growth of a Planar Crack Front in Three-Dimensional Body Subjected to Mode I Loading
Authors: Stan Felicia
Published: July 2009

In this paper, a methodology is presented for predicting crack growth rate along three-dimensional crack fronts under mode I dynamic loading conditions. Within the present methodology, for every point along the crack front the stress intensity factor matches the dynamic fracture toughness at the onset of propagation. In order to accurately evaluate the dynamic stress intensity factor the component separation method of the dynamic J integral is used. To overcome the difficulties in three-dimensional dynamic fracture simulations, the three-dimensional dynamic moving finite element method based on three-dimensional moving 20-noded isoparametric elements is used. In the absence of experimental measurements for dynamic fracture toughness, a new methodology to estimate the dynamic fracture toughness is proposed, i.e., a hybrid experimental-numerical approach, which makes use of numerically determined histories of the dynamic stress intensity factor. The values of the dynamic stress intensity factor are converted into dynamic fracture toughness based on the Weibull distribution. The predictive ability of the developed methodology is demonstrated through the prediction of the dynamic crack growth in Double Cantilever Beam (DCB) specimen of PMMA with different thickness.
Bubble Formation Modeling in Matrix-Assisted Pulsed-Laser Evaporation Direct Write
Authors: Lin Yafu , Foy Kevin , Huang Yong , Chrisey Douglas B.
Published: July 2009

Matrix-assisted pulsed-laser evaporation direct write (MAPLE DW) is emerging as a promising direct-write technology for printing microelectronics as well as biological constructs. To widely employ this technology, understanding of its physical mechanism is of need. In this study, the bubble formation process in MAPLE DW of glycerol-water coating is modeled based on the nucleation-based phase explosion theory. Based on the proposed model, the bubble diameter after expansion and cooling and bubble pressure can be predicted. Although the prediction overall overestimates the bubble diameter during the MAPLE DW experiments, the proposed model is considered satisfactory in reasonably predicting the bubble diameter as a first step endeavor for this complex process. It is expected that the introduction of more accurate models for energy loss should further help improve the model prediction accuracy.
Modeling of Bubble Expansion-Induced Cell Mechanical Profile in Laser-Assisted Cell Direct Writing
Authors: Wang Wei , Li Gang , Huang Yong
Published: July 2009

Cell damage due to the mechanical impact during laser-assisted cell direct writing has been observed and is a possible hurdle for broad applications of fragile cell direct writing. The objective of this study is to numerically investigate the bubble expansion-induced cell mechanical loading profile in laser-assisted cell direct writing. Some conclusions have been drawn as follows. The cell velocity oscillates initially and then smoothes out gradually with a constant ejection velocity. Both the cell acceleration and pressure can be very high at the beginning period of bubble expansion and then quickly approaches zero in an oscillation manner. A high viscosity can lead to an observable velocity increment at the initial stage, but the ejection velocity decreases. The pressure magnitude decreases when the distance is large, and a larger initial pressure induces a larger cell pressure as expected. This study serves as a foundation to further investigate the cell damage mechanism in laser-assisted cell direct writing to improve the effectiveness and efficiency of cell direct writing techniques.
Laser Polishing Parameter Optimization for Die and Moulds Surface Finishing
Authors: Ukar E. , Lamikiz A. , Lo´pez de Lacalle L. N. , Liebana F. , Etayo J. M.
Published: July 2009

Final polishing operation for die and mould manufacturing represents up to 30% of the total manufacturing cost and it is a high added value operation carried out manually by qualified personnel. The work presented in this paper proposes an automated solution for this task by the process known as Laser Polishing. This process is based on the application of a laser beam melting a microscopic layer of material, which lately solidifies filling the gaps, and smoothing the overall topography. Several Laser Polishing tests have been done with CO2 and High Power Diode Lasers (HPDL) on two different materials commonly used in die and mould industry: a DIN 1,2379 Tool Steel tempered up to 62HRC, used for injection moulds inserts, and a spheroidal graphite Cast Iron DIN GGG70L used typically on large stamping dies manufacturing. By means of the tests and Design of Experiments (DoE) technique, the operation parameters for the Laser Polishing process as well as its degree of influence in the melted surface have been defined. Starting off from an initial surface obtained by means of High Speed Milling operation, it has been possible to obtain satisfactory results with final roughness reductions higher than 80% with respect to the initial values, and mean roughness values below 0.8μm Ra.
A Parametric Study on Overlapping Laser Shock Peening of 4140 Steel via Modeling and Experiments
Authors: Cao Yunfeng , Shin Yung C. , Wu Benxin
Published: July 2009

Laser shock peening (LSP) under the water confinement regime (WCR) involves several complicated physical phenomena. Among these phenomena, the interaction between laser and coating material during LSP is very important to the laser induced residual stress, which has an important effect on the fatigue and corrosion properties of the substrate material. To gain a better understanding of this interaction, a series of experiments, including single shot, single track overlapping, and multi-track overlapping LSP, have been carried out on 4140 steel with black paint coating. A 3-D finite element model has also been developed to simulate the LSP process. Combining this with a previously developed confined plasma model, which has been verified by the experimental data from literature, the 3-D finite element model is used to predict the residual stresses induced in the substrate material as well as the indentation profile on the substrate surface. The model prediction of indentation profiles are compared with the experimental data and good agreements are obtained. The effect of process parameters on the residual stress has also been investigated both experimentally and theoretically.
Investigation of Optimal Parameter Space for High-Speed, High-Precision Micromilling
Authors: Mayor J. Rhett , Sodemann Angela A.
Published: July 2009

In this paper, it is shown that due to scale effects in micromilling, tool size is a key parameter to consider in parameter optimization for productivity in a high-speed, high-precision micromilling operation. In this preliminary study, a method is proposed to determine the optimal tool sizes for roughing and finishing cuts in a micromilling operation, and corresponding feedrate and spindle speed profiles to maximize productivity. An objective function is developed for minimization, subject to a set of constraints. This paper will develop the framework of the optimization method and will consider constraints for sufficient reduction of geometric errors and achievability under spindle speed power limitations in particular. An algorithm is presented to solve the objective function assuming use of a roughing tool and a finishing tool. A numerical case study is presented to illustrate the implementation of the method.
Manipulating Shape and Size of Nanoparticles With Plasma Field
Authors: Deng Tao , Cournoyer James R. , Schermerhorn James H. , Balch Joleyn , Blohm Margaret L.
Published: July 2009

Tuning the plasma field in reactive ion etching generates different etching profile of nanoparticles. For nanoparticles in an isotropic plasma field, there will be uniform shrinkage of the particle sizes due to the isotropic etching, with the curvature of the particles unchanged after the etching. An anisotropic etching, on the other hand, provides rich opportunities to modify the shape of the particles with reduced dimensions. For a monolayer of silica nanoparticles on a flat substrate in a unidirectional plasma field, the reactive ion etching changed the shape of silica nanoparticles from spherical to spheroid-like geometry. The mathematical description of the final spheroid-like geometry was discussed and matched well with the experimental results. The surface curvature of the particles after etching remained the same for both the top and the bottom surfaces, while the overall shape transformed to spheroid-like geometry. Varying the etching time resulted in particles with different height to width ratios. The unique geometry of these non-spherical particles will impact fundament properties of such particles, such as packing and assembly. In the case of spheroid-like particles, packing of such particles into ordered structures will involve an orientational order, which is different from spherical nanoparticles that have no orientational order.
Mechanical Properties of PDMS and Influences by Micromachining Processes
Authors: Sun Jianren , Bock Christopher , Chen Quanfang
Published: July 2009

Microfluidics is both a science and a technology that offers great and perhaps even revolutionary capabilities to impact the society in the future. Polydimethylsiloxane (PDMS) has been widely used in fabricating microfluidic systems but few efforts were made in the past on mechanical properties of PDMS. Very importantly there is no report on influences of microfabrication processes which normally involve chemical reaction processes. A comprehensive investigation was made by authors to study fundamental issues regarding chemical emersion and their effects on mechanical properties of PDMS. Results shown in this work can be used to guide future developments of microfluidics in utilizing PDMS especially those devices involve actuation of PDMS membranes.
Feature-Based Tool Condition Monitoring in a Gear Shaving Application
Authors: Brzezinski A. J. , Wang Y. , Choi D. K. , Qiao X. , Ni J.
Published: July 2009

Condition monitoring (CM) is an effective way to improve the tool life of a cutting tool. However, CM techniques have not been applied to monitor tool wear in an industrial gear shaving application. Therefore, this paper introduces a novel, sensor-based, data-driven, tool wear estimation method for monitoring gear shaver tool condition. The method is applied on an industrial gear shaving machine and used to differentiate between four different tool wear conditions (new, slightly worn, significantly worn, and broken). This research focuses on combining, expanding, and implementing CM techniques in an application where no previous work has been done. In order to realize CM, this paper discusses each aspect of CM, beginning with data collection and pre-processing. Feature extraction (in the time, frequency, and time-frequency domains) is then explained. Furthermore, feature dimension reduction using principal component analysis (PCA) is described. Finally, feature fusion using a multi-layer perceptron (MLP) type of artificial neural network (ANN) is presented.
Implementation of Multirate Estimation for the Cylindrical Grinding Process
Authors: Lee Cheol W.
Published: July 2009

This paper presents implementation results of the multirate estimation scheme, proposed by Lee (Lee, C.W., 2007, “Multirate Estimation for the Machining Process under Multirate Noise,” Proceedings of the 2007 ASME IMECE, November 11–15, 2007, Seattle, WA), on the cylindrical plunge grinding process. The multirate scheme is an efficient tool for integrating real-time sensor signals with postprocess inspection data for estimating the immeasurable variables. In order to accomplish this goal, process models for grinding power, surface roughness and wheel wear are developed using experimental data. Case studies are performed on simultaneous state-parameter estimation for actual grinding batches after the multirate observers are built based on the process models. Results from case studies validate the applicability of the proposed scheme to challenging estimation tasks in the manufacturing industry that cannot be undertaken by traditional approaches.
Graphical MPC for Fast Dynamic Systems
Authors: Dunia Ricardo , Gutierrez Javier
Published: July 2009

Software configuration and engineering costs have limited the application of model predictive control (MPC) for small but fast dynamic systems. This work illustrates the benefits of using a graphical programming framework for the configuration and implementation of MPC controllers. Graphical programming facilitates the understanding and configuration of advanced applications so that engineers in industry can be responsible for the installation and maintenance of advanced controllers. Costs reduction and minimal specialized labor opens the possibilities of applying MPC to small systems with fast dynamics. Fast MPC execution is achieved by including the optimization constraints as penalty terms in the cost function. An air-heater pilot system is successfully used to demonstrate the advantages of a graphical framework for process modeling, design, and real-time implementation of MPC controllers in systems with fast dynamics.
Development of a PC-Based Millimeter Scale CNC Turning Centre With Gear Hobbing Capability
Authors: Liu Shiqing , Chan Sunny , Ching Ho , Kong Tom Ching , Du Ruxu
Published: July 2009

Currently, a trend of extreme product miniaturization is particularly evident in sectors such as portable multimedia devices, communications, aerospace and biomedical devices. With increasing product compactness, the demand for precision miniature components is driven higher and higher and the ability to manufacture these components accurately, swiftly and cost effectively is critical for manufacturers to maintain market competitiveness. However, traditional machine tools become ineffective for cutting miniature components. This paper presents our efforts in developing a PC-based millimeter scale turning centre (referred to as MMT hereafter) with gear hobbing capability to machine miniature gears. The system architecture of our 2nd-gerneration MMT is given. In order to fine-tune the micro gear hobbing process to maximize the gear profile accuracy, the mechanics of the process must be thoroughly understood. In order to do so, a computer simulation tool is developed. The simulation procedure and simulation with different process defects are discussed in detail. Experiment results show that the machine is able to machine high quality components with diameter as small as 0.075 mm and hob gears with module as small as 0.3mm.
Smart Machine Health and Maintenance: Tool Assembly Prognostics
Authors: Lapira Edzel R. , Deshpande Amit , Lee Jay , Snyder John
Published: July 2009

It is well-established that unbalance in tool assembly causes excessive loads on spindle bearings and tool wear and increased vibration levels. However, in the days where high-speed machining (HSM) has become a common practice in the manufacturing industry, methodologies to measure tool assembly unbalance are not developed. In HSM the effects are worse, as the unbalance force is directly proportional to square of the spindle speed. Common practice in industry is to balance the tool assembly either with in-house balancing machines or use third-party balancing services after every batch cycle. This paper describes a data-driven methodology that detects the presence of unbalance in a tool assembly relative to the tools with known balance levels. The unbalance detection prognostic application developed as part of the Smart Machine Platform Initiative (SMPI) checks for the threshold unbalance level in the tool assembly for the given machining requirements before the start of any run. This approach uses statistical tools and a supervised learning algorithm based on the Watchdog Agent® toolbox developed by the Center for Intelligent Maintenance Systems. The proposed research finds high applicability in high-precision manufacturing operations involving high-volume production.
Calibration of a Milling Force Model Using Feed and Spindle Power Sensors
Authors: Javorek Bryan , Fussell Barry K. , Jerard Robert B.
Published: July 2009

Changes in cutting forces during a milling operation can be associated with tool wear and breakage. Accurate monitoring of these cutting forces is an important step towards the automation of the machining process. However, direct force sensors, such as dynamometers, are not practical for industry application due to high costs, unwanted compliance, and workspace limitations. This paper describes a method in which power sensors on the feed and spindle motors are used to generate coefficients for a cutting force model. The resulting model accurately predicts the X and Y cutting forces observed in several simple end-milling tests, and should be capable of estimating both the peak and average force for a given cut geometry. In this work, a dynamometer is used to calibrate the feed drive power sensor and to measure experimental cutting forces for verification of the cutting force model. Measurement of the average x-axis cutting forces is currently presented as an off-line procedure performed on a sacrificial block of material. The potential development of a continuous, real-time force monitoring system is discussed.
Microstructure and Mechanical Properties of ZrO2(Y2O3)-Al2O3 Nano Composites Prepared by Spark Plasma Sintering
Authors: Li Shufeng , Izui Hiroshi , Okano Michiharu , Zhang Weihua , Watanabe Taku
Published: July 2009

Zirconia (Y2O3)-alumina ceramic nanocomposites were fabricated by spark plasma sintering (SPS). A commercially available nanocomposite powder TZP-3Y20A was used as starting powder, the other from conventionally mechanical mixed powder 3YSZ-20A used for comparison. The effect of sintering temperature on the densification, sintering behavior, mechanical properties, and microstructure of the composites were investigated. The results show that the density increase with increasing of sintering temperature, and thus mechanical properties were strengthened with enhancing of densification. The nanocomposite powder TZP-3Y20A was easily sintered and good mechanical properties were achieved, compared with the powder from conventionally mechanical mixed, where the maximum strength and toughness of composites are 967 MPa and 5.27 MPam1/2, respectively.
Microstructure and Material Analysis of Worn WC-Co Ball-End Mills
Authors: Kuo Hsin-Yu , Meyer Kevin , Lindle Roger , Weaver Howard , Ni Jun
Published: July 2009

The objective of this study is to examine the relationship between microstructure and material content at critical locations of used WC-Co ball-end mills. The performance of three similar tools was tested at identical cutting conditions. From each tool, three samples were cut from the same positions on the WC-Co ball-end mills at key locations. Scanning Electron Microscopy (SEM) was used for observation of the microstructure of material and three methods were used to determine the chemical compositions of each tool. The first method used to examine the chemical composition was Energy Dispersive Spectrometry (EDS). Higher accuracy chemical analysis using Wave Dispersive Spectrometry (Microprobe) techniques and Slice-Averaged Wet Chemistry (ICP) results were also completed to verify trends and chemical contents. The results of this study showed that the microstructure is closely related to the cobalt content. Moreover, cobalt losses resulting from the machining process as well as phenomena resulting in microstructure defects in the manufacturing stage of the carbide were evident in worse performing tools. Furthermore, differing grain-growth inhibitor contents of each tool might have led to additional performance differences.
Processing of ZrW2O8-ZrO2 Continuous Functionally Graded Materials by Co-Sintering ZrO2 and ZrO2+WO3 Multi-Layer Compacts
Authors: Sun Li , Baldauf Sam , Kwon Patrick
Published: July 2009

A powder mixture of ZrO2+WO3 and ZrO2 powder were stacked, co-compacted and co-sintered in the processing steps commonly used to fabricate multi-layer materials. However, the observation of the cross-sectional microstructures as well as the measurement of the radial thermal expansion provided the evidence that the sintered samples are continuous Functionally Graded Materials (FGMs) made of ZrW2O8 and ZrO2, Because of the discrepancy in the sintering potentials between two materials, the sintered samples do not retain the original cylindrical shapes of the green compacts. This problem has been resolved by choosing the appropriate powder mixture for each layer of the compacts. The formation of the continuous FGM structure is due to three factors: 1) the diffusion of WO3, 2) the sublimation of WO3 and 3) the reaction between ZrO2 and WO3. The continuous variation in the radial coefficient of thermal expansion can be utilized to reduce the thermal stress induced from a thermal gradient loading within a material system. This study shows that the processing steps typically used in processing stepwise FGMs can also be used to create continuous FGMs for some special powder mixtures.
Alternative Binder Carbide Tools for Machining Superalloys
Authors: Waldorf Daniel , Liu Scott , Stender Michael , Norgan Daniel
Published: July 2009

This study examines the performance of a new class of wear-resistant but economical cutting tools produced by varying the binder composition of standard cemented carbide composites. By replacing some or all of the cobalt binder with rhenium and nickel-based superalloy, a stronger composite tool results, potentially capable of machining heat-resistant superalloys at significantly higher cutting speeds. Sample tools with alternative binder were produced and compared to standard tools bound with cobalt only. Turning experiments on Inconel 718 were run to evaluate wear resistance and tool life for several grades. The experimentation also examined the effects of varying the relative proportions of each binder constituent as well as the overall binder percentage in the composite. Results show a clear advantage of the alternative binder tools as evidenced by a 150% increase in tool life or the equivalent of an 18% increase in cutting speed. Although increasing amounts of rhenium in the binder show a positive effect on performance, the effects of superalloy and overall binder % are inconclusive.
A Meso-Scale Micro-Turning Machine With Modular Linear Air-Bearing Stages
Authors: Ro Seung-Kook , Jang Sung-Kweon , Park Jong-Kwoen
Published: July 2009

In this paper, we describe the design, fabrication, and evaluation of a compact-sized diamond turning machine built with two air-bearing stages and a spindle. The two stages were developed to achieve the precise positioning required for submicron-level machining and miniaturization by introducing air bearings and a linear motor sufficient for mesoscale precision machine tools. The linear motor contained two permanent magnets and was designed to generate a preload force for the vertical air bearings and a thrust force for the stage movement. The size of the single-axis miniature stage was 120 × 120 × 50 mm3, and the footprint of the turning machine was 200 × 350 mm2, which is small enough for a tabletop. The positioning repeatability of the each linear axis was measured to be 0.05 μm, and the machining error and was evaluated by cutting various depths of an aluminum alloy mirror with a single-crystal diamond. The estimated workpiece–tool stiffness was lower than that with conventional ultraprecision machine, but a form error of less than 0.16 μm and a surface roughness (Rz) of 0.08 μm were achieved by the finishing cut using a small depth of cut. This reveals that miniaturized machines can be used successfully for precision machining of small precision parts.
Crater Wear Patterns and Evolution on Multi-Layer Coated Carbides Using the Wavelet Transform
Authors: Olortegui-Yume Jorge A. , Yoon Moon-Chul , Kwon Patrick Y.
Published: July 2009

The crater topography of wear patterns on a series of multi-layer coated tools after machining for a series of machining times has been measured using Confocal Laser Scanning Microscopy and Stylus Profilometry in order to study the crater wear patterns and their evolution. The crater profile and raw patterns were processed using multi-resolution 1D and 2D wavelet analysis to eliminate noise, spike/pits and then to decouple the large/short scale wear features in order to examine the development and history of crater wear accurately. The wavelet method proved to be very powerful to extract the meso-scale crater wear pattern free of noise/artifacts without losing the general crater pattern. Microscale details were successfully identified which indicates a great potential for the local analysis of wear mechanisms.
Study of the Sandwich Sheet Metal Cup Drawing Characteristics
Authors: Chen Jun , Wang Yong , Li Haibo
Published: July 2009

The sandwich sheet is a novel laminated sheet material with advanced vibration damping advantages, and the sheet is composed with 2 outer thick metal layers and 1 thin polymer layer in between. In order to investigate its drawing characteristics, an improved cohesive model between the skin sheets was developed using a contact/interface approach. Based on the proposed model, a cup drawing process was numerically simulated using commercial FEM code ABAQUS. Numerical simulation shows that the thickness strain distribution and thinning phenomenon have similar modes on the top layer and bottom layer except at the cup bottom corner, and cohesive strength does not have severe effect to the drawing force. The drawing experiments were conducted on a hydrauic press in order to compare the whole sheet and two skin sheets thickness distribution of sandwich sheet metal cup drawing, FEM simulation result fits well with the experiment.
Numerical Investigation of Temperature Field During Sintering of Bioceramic Nanoparticles by Pulse Lasers
Authors: Ye Chang , Cheng Gary J.
Published: July 2009

Traditional numerical study of the temperature field of laser thermal processing is based on two assumptions: 1. heat source is a surface heat flux, and 2. uniform material properties. This method is not accurate when it comes to the laser sintering of nanoparticle integrated bioceramics coating with certain porosity. In this paper, Heat transfer (HT) model and electromagnetic (EM) model is coupled to investigate the temperature field of bioceramics nanoparticles. The heat source calculated from EM field is simultaneously input into the HT model to calculate the temperature field of the nanoparticle assembly. The interaction between the nanoparticles in the EM field is analyzed and its influence to the optical penetration depth of laser is discussed. The effects of laser parameter, including wavelength, pulse energy, pulse width, and mixing ratio of nanoparticles are also investigated.
Fatigue Crack Growth Behavior of High Carbon Steel (SM53C) by Using Induction Hardening
Authors: Jeon Hyun Bae , Song Tae Hoon , Park Sung Ho , Huh Sun Chul , Park Won Jo
Published: July 2009

Recently, with the high performance and efficiency of machine, there have been required the multi-functions in various machine parts, such as the heat resistance, the abrasion resistance and the stress resistance as well as the strength. Fatigue crack growth tests were carried out to investigate the fatigue characteristics of high carbon steel (SM53C) experienced by high-frequency induction treatment. The influence of high-frequency induction treatment on fatigue limit was experimentally examined with the special focus on the variation of surface microstructure and the fatigue crack initiation and propagation through fractography. Also, the shape of hardening depth, hardened structure, hardness, and fatigue-fracture characteristics of SM53C composed by carbon steel are also investigated.
Surface Finish in Hard Machining by PVD-Coated End-Mills Using Solid Lubricant
Authors: Biradar Shantisagar , Lathkar Geeta , Basu S. K.
Published: July 2009

The paper deals with machining of High C–High Cr die steel with Ti N, TiAlN Coated end mill cutter, using solid lubricant and obtaining a generalised relationship of surface roughness dependent on input parameters, based on response surface methodology. The hardness ratio of the tool and the workpiece, as one of the important parameters, having significant influence under near-dry machining condition, was studied under minimum quantity of oil using solid-lubricant (MOS2) mixed with base oil SAE-20 in different proportion.
Thermal Reflow Process for Glass Microlens Manufacturing
Authors: Chen Yang , Yi Allen Y. , Yao Donggan , Klocke Fritz , Pongs Guido
Published: July 2009

This fabrication process includes three major steps, i.e., fabrication of glassy carbon molds with arrays of micro size holes, glass compression molding to create micro cylinders on glass substrate, and reheating to form microlens arrays. As compared to traditional polymer microlens arrays, glass microlens arrays are more reliable and therefore could be used in more critical applications. In this research, microlens arrays with different surface geometries were successfully fabricated on P-SK57 (Tg = 493 °C) glass substrate using a combination of compression molding and thermal reflow process. The major parameters that influence the final lens shape, including reheating temperature and holding time, were studied to establish a suitable fabrication process. A numerical simulation method was developed to evaluate the fabrication process.
Improved Performance of Polymethyl Methacrylate for Minimally Invasive Orthopedic Implants
Authors: Schroeder Megan , Schmid Steven R.
Published: July 2009

Polymethylmethacrylate (PMMA) based polymers are commonly used in orthopedic implant applications, and have been a successful cement for many decades. Recent implant designs use PMMA as a structural material, and additional applications are envisioned, but only if improvements in the PMMA mechanical properties, especially fatigue performance, can be attained. This paper presents a number of strategies for improving the performance of PMMA as an orthopedic structural polymer, including modification of the polymer chemistry, incorporation of acrylic reinforcement and the use of metal braids as reinforcement of a specimen exterior. Experimentally measured properties of the material are presented. Results include up to 100% increase in cycles to failure compared to commercially available medical grade PMMA through chemistry modifications, up to 800% increases due to fiber reinforcement, and further significant improvements due to metal braid reinforcement.
Assessment of the Process Parameters and Their Effect on the Chip Length When Using CNC Toolpaths to Provide Chip Breaking in Turning Operations
Authors: Woody Bethany A. , Smith K. Scott , Adams David J. , Barkman William E.
Published: July 2009

Past work at UNC Charlotte has demonstrated that the use of oscillating CNC toolpaths provides a reliable chip breaking alternative to conventional methods such as the use of cutting inserts with special geometries and/or adjusting machining parameters. The specific toolpath geometry and the selection of the oscillating parameters is an important step to reliably and constantly create broken chips using this new method. This paper builds on the past work and discusses the proper selection of oscillation amplitude and its effect on the ability to break chips and to achieve desired chip lengths.
Electrospun Nanocomposites as Flexible Sensors
Authors: Tiwari Manish K. , Yarin Alexander L. , Megaridis Constantine M.
Published: July 2009

Electrospun polymer/nanoparticle composite-fiber strips are introduced as permeable, flexible strain sensors. The composite strips are referred as nanocomposite in this study. In the experiments with uniaxial elongation, the nanocomposite strips showed a reproducible increase in electrical resistance indicating the strain level. The resistance increase was interpreted with a novel percolation model that accommodated changing strips geometry. A theoretical framework for nanocomposites as possible detectors of local clogging in large-scale filters is also proposed.
Visual Simulation of Aristo Robot With Workspace Analysis
Authors: Parghi Upendra K. , Raval H. K.
Published: July 2009

Robotics is a technology that is utilized tremendously in Industrial and Commercial Applications. Different types of robotic arms are used to fulfill the industrial needs. The aim of the work presented in this paper is to give a visual simulation of the robotic arm (Aristo Robot – 6 DOF) which can be used with offline robotic programming thereby introducing the language to the user and creating a training package for the user. This software also reduces the time as programming can be done offline. The pick and place robotic arm comprises of 6 links, which each of them has one degree of freedom (DOF) with a payload capacity of 3 kg is used for visual simulation. The main objective is to design a three dimensional graphic of a robotic arm and its movement animation that imitates the movement of actual robotic arm. The graphic design is then used as a foundation to find its limits of reach in the surrounding. Also the analysis of workspace is done to understand its workspace volume properly.
Experimental Investigation on Diamond Drilling of Potassium Di-Hydrogen Phosphate (KDP) Crystal
Authors: Wang Qiangguo , Pei Z. J. , Gao Hang , Churi N. J. , Kang Renke
Published: July 2009

KDP (potassium di-hydrogen phosphate) crystal is used to fabricate important electro-optic parts. It is a typical hard-to-machine material because it is soft, brittle, and anisotropic. Parts made of KDP usually have extremely high requirements for machining quality. Reported machining methods so far for KDP crystal include single point diamond turning, grinding, magnetorheological finishing, and polishing. This paper presents an experimental investigation on diamond drilling of KDP. Data of several output parameters (including grinding force and torque, surface roughness, and edge chipping) were collected and analyzed. Ultrasonic vibration was superimposed to the rotation of the tool to study its effects.
Economic and Environmental Assessment of Automotive Remanufacturing: Alternator Case Study
Authors: Kim Hyung-Ju , Raichur Vineet , Skerlos Steven J.
Published: July 2009

Remanufacturing is a process that restores old products to perform like new, while saving energy, reducing consumption of natural resources, and lowering environmental emissions. By extending the product life cycle, remanufacturing approaches enable closed loop material cycles that are ultimately necessary for a sustainable society. This paper provides some description of the current automotive remanufacturing enterprise, with a particular emphasis on key vehicle components that are currently remanufactured. The analysis yields two major conclusions. First, market price of a remanufactured component in the automotive sector is surprisingly uncorrelated with the number of companies engaged in remanufacturing that component — at least for companies registered with the Automotive Parts Remanufacturing Association (ARPA). Second, and less surprisingly, we find that remanufacturing reduces environmental burden significantly over new production. This improvement, for the case of the alternator used as a case study, can easily exceed one order of magnitude in the categories of material use, energy consumption, and greenhouse gas (GHG) emissions that are considered here.
A Low Cost Wireless Tool Tip Vibration Sensor for Milling
Authors: Suprock Christopher A. , Fussell Barry K. , Hassan Raed Z. , Jerard Robert B.
Published: July 2009

A low cost, wireless vibration sensor system has been developed for noninvasive integration into commercial end milling tool holders. Electret based accelerometers are used as the sensors and a Bluetooth compatible digital transmitter is used as the sensor interface. The use of mass market consumer electronic components is low cost and plug and play with modern PC hardware. Two prototypes were built and, in both cases, were able to collect good quality data at high sampling rates. The objective of the research is to enable accurate observation of NC metal cutting system dynamics. Initial results indicate the system can be used to estimate tool runout and detect the onset of regenerative chatter, prior to workpiece damage.
Spot Friction Weld Strength Improvement Through In-Process Metal Matrix Formation
Authors: Arul Senthil , Kruger Grant H. , Miller Scott F. , Pan Tsung-Yu , Shih Albert J.
Published: July 2009

The effects of metal matrix composite (MMC) on the joint strength of Spot Friction Welded (SFW) specimens made of Al 1100 and Al 6111 alloys are studied. The MMC-SFW joints were created by sandwiching metal reinforcing powder (<75μm mesh) between the upper (1.3mm thick) and lower (1.5mm thick) Al coupons, at the center of the SFW joint. To maximize the heat input into the specimen, a Zirconium (ZrO2) ceramic anvil was used. Depth of penetration of the tool played an important role in determining the distribution of the reinforcing material within the MMC during plastic mixing in the SFW joint, and hence its influence on the joint strength. At a lower depth of penetration, 2.1 mm, the results showed that the MMC-SFW reinforced with Ancorsteel 1000, copper or Al12Si powders did not increase the joint strength since they did not spread uniformly in the stir zone. However, at a higher depth of penetration, 2.5 mm, the MMC-SFW joint reinforced with Ancorsteel 1000, copper, or Al12Si did increase the joint strength compared to that of the base SFW specimens. Using steel powder as the reinforcement material, the MMC showed the maximum increase in the lap shear joint strength. For example, at 2.5 mm depth of penetration, the SFW joint strength increased by 19% and 24% compared to that of the base SFW specimen made of Al 1100 and Al 6111 alloys respectively.
Characterization of a Nano-Composite Sensor in Multiple Environmental Domains
Authors: Chimalapati Swathi , Mears Laine , Clark Andrew C.
Published: July 2009

A sensor composed of a composite material formed of a polymer and nano-carbon conductive filler is characterized for measurement of pressure through the relationship to contact resistance. The sensor has the physical attributes of polymer, but is electrically conductive and can therefore be used on a conductive substrate to gauge pressure and subsequently load. Benefits over traditional force sensing include reduced cost, full control of geometry, reduced form factor, resistance to impact and to corrosion. A test circuit was developed to study the behavior of the sensor at different loads and surface conditions, and behavior over time. Prospective applications on manufacturing and automotive fields are proposed.
Characteristics of Acoustic Emission Signals in Machining Using Diamond Coated Tools
Authors: Hu Jianwen , Qin Feng , Chou Kevin , Thompson Raymond G.
Published: July 2009

Diamond coated cutting tools have been pursued as a cost-effective substitute to brazed polycrystalline diamond (PCD) tools in applications such as machining high-strength and lightweight materials. However, coating delamination has been known as the major failure mode of diamond coated tools, which terminates tool life prematurely. Once delamination failure occurs, the tool substrate often subjects to severe abrasive wear leading to catastrophic tool failures that imparts the part quality and interrupts machining operations. Hence, accurate detections and forecasts of coating delamination events can prevent production loss and assist process planning. In this study, the characteristics of acoustic emission (AE) signals when machining a high-strength aluminum alloy and a composite using diamond coated cutting tools were investigated. The AE signals were analyzed in both time and frequency domains at various machining conditions and different cutting times. It was found that AE root-mean-square values decrease considerably once coating delamination occurs. The results also indicate a correlation between the tool condition and fast Fourier transformation (FFT) spectra of AE raw data. In addition, the machining experiments implied that it may be feasible to use AE signals to monitor the condition of diamond coated tools during machining.
Green Manufacturing of Electricity for Stationary Industrial Applications
Authors: Ali-Qureshi Zulfiqar
Published: July 2009

On-site power generation in industrial plants are desirable, however, this may not contribute as a significant source of pollution to the environment. In order to lower the potential impact on the environment in terms of less toxic emissions, to save useless cost and the sustainability, manufacturer’s responsibilities become more than end-of-pipe control and includes end-of-life management. Green manufacturing is the method that minimizes waste and pollution achieved through product and process life cycle design. The cradle to grave analysis in green manufacturing system provides the complete analysis in every aspect of the sustainable manufacturing system for policy makers to take decisions. In this paper the renewable source of alternate energy manufacturing system has been analyzed for production of power. The renewable energy from hydrogen and (green gas synthetic natural gas) for generation of electricity focusing large stationary application set up has been studied. A prototype model has been developed in order to draw analogy for establishing future Industrial power parks of mega energy productions in order to meet the peak load requirements of the electricity consumption. The results has been analyzed and comparison have also been made for the purpose to apply green industrial manufacturing process in renewable energy sector as much as possible for reducing waste and with zero potential environmental burden on our Eco-system.
Effect of Electrical Pulsing on Various Heat Treatments of 5XXX Series Aluminum Alloys
Authors: Salandro Wesley A. , Jones Joshua J. , McNeal Timothy A. , Roth John T. , Hong Sung-Tae , Smith Mark T.
Published: July 2009

Previous studies have shown that the presence of a pulsed electrical current, applied during the deformation process of an aluminum specimen, can significantly improve the formability of the aluminum without heating the metal above its maximum operating temperature range. The research herein extends these findings by examining the effect of electrical pulsing on 5052 and 5083 Aluminum Alloys. Two different parameter sets were used while pulsing three different heat treatments (As Is, 398°C, and 510°C) for each of the two aluminum alloys. For this research, the electrical pulsing is applied to the aluminum while the specimens are deformed, without halting the deformation process. The analysis focuses on establishing the effect the electrical pulsing has on the aluminum alloy’s various heat treatments by examining the displacement of the material throughout the testing region of dogbone shaped specimens. The results from this research show that pulsing significantly increases the maximum achievable elongation of the aluminum (when compared to baseline tests conducted without electrical pulsing). Significantly reducing the engineering flow stress within the material is another beneficial effect produced by electric pulsing. The electrical pulses also cause the aluminum to deform non-uniformly, such that the material exhibits a diffuse neck where the minimum deformation occurs near the ends of the specimen (near the clamps) and the maximum deformation occurs near the center of the specimen (where fracture ultimately occurs). This diffuse necking effect is similar to what can be experienced during superplastic deformation. However, when comparing the presence of a diffuse neck in this research, electrical pulsing does not create as significant of a diffuse neck as superplastic deformation. Electrical pulsing has the potential to be more efficient than traditional methods of incremental forming since the deformation process is never interrupted. Overall, with the greater elongation and lower stress, the aluminum can be deformed quicker, easier, and to a greater extent than is currently possible.
Determination of Cutting Forces for Micro Milling
Authors: Wang Shih-Ming , Chiang Zou-Sung , Chen Da-Fun
Published: July 2009

To enhance the implementation of micro milling, it is necessary to clearly understand the dynamic characteristics of micro milling so that proper machining parameters can be used to meet the requirements of application. By taking the effect of minimum chip thickness and rake angle into account, a new cutting force model of micro-milling which is function the instantaneous cutting area and machining coefficients was developed. According to the instantaneous rotation trajectory of cutting edge, the cutting area projected to xy-plane was determined by rectangular integral method, and used to solve the instantaneous cutting area. After the machining coefficients were solved, the cutting force of micro-milling for different radial depths of cut and different axial depths of cut can be predicted. The results of micro-milling experimental have shown that the force model can predict the cutting force accurately by which the optimal cutting parameters can be selected for micro-milling application.