bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Comparison of Three Kinds of Structures for Fabric Keyboard Switch
Authors: Zhang Mei Ling , Wang Rui , Ye Jian Qing , Wang Zhan Gang
Published: August 2010

Flexible fabric keyboard is a field of smart textile. It can overcome traditional horniness keyboard can’t be foldable and washing. Because conventional keyboard’s switch is matrix circuit, two conductive layers are not touchable due to action of a middle insulating layer in relaxing. When the key is pressed, two conductive layers contact and form electric current. In this laboratory study there are three kinds of structure designed such as through-thickness angle interlock, trapezia and X shape structure which consist of the support part and the orifice part. Conductive filaments are 8 roots for the warp and weft conductive material. Then the weaving time, elastic modulus and connection pressure are tested and analyzed for every kind of fabric keyboard switch. It is concluded that the weaving time of through-thickness angle interlock is the shortest and the elastic modulus of X shape structure is the best, but connection pressure of three kinds of structures is all big. These findings may assist in recommendations regarding the further development of flexible fabric keyboard.
Evaluation of Fracture Toughness of Ceramic-Metal Functionally Graded Materials
Authors: Rasel Sheikh Md. , Mirza Foisal Ahmed , Afsar Ali Md. , Song Jung Il
Published: August 2010

The main objective of this study is to examine the two dimensional surface crack problems in a system with an interface between two elastic-plastic solids of different yield strength subjected to mode I mechanical loading. The surface cracks growth is considered to occure along the interface direction of bimaterials which is perfectly bonded to each others. A two dimensional finite elementmethod is used to solve the structural problem. Solid 183-node elements are utilized to simulate the strain singularity around the crack front. The crack surface is subjected to a compressive load by three point bending. The stress intesity factors are computed by using the displacement correlation technique. The primary goal is to develop a model crack tip stresses and strains in a manner that is useful for crack growth initiation and propagation in a FGM.
Evaluation of the Preparation and Biocompatibility of Poly(vinyl Alcohol)(PVA)/Chitosan Composite Electrospun Membranes
Authors: Huang Chao Chiung , Lou Ching Wen , Lu Chao Tsang , Huang Sin Huei , Chao Chieh Yu , Lin Jia Horng
Published: August 2010

Electrospinning has been used in a wide variety of applications, such as tissue engineering, filtration and biomaterial scaffolds for vascular grafts or wound dressings. Recently, wound dressings have become more important in human life. They must have the superior biocompatibility, water absorption, water vapor permeation and antibacterial ability. Chitosan has been employed in clinical applications and exhibits excellent biocompatibility, biodegradation and bacteriostasis. In this investigation OR study, experiments were performed on a series of poly (vinyl alcohol) (PVA)/Chitosan (CS) fiber membranes at various blend ratios and electric fields to evaluate their spinnability. The morphology, diameter and structure of electrospun nanofibers were examined by scanning electron microscopy (SEM). When PVA/Chitosan=80:20 and electric field=0.67 kV/cm, the spinnability of electrospun membrane was good. IR spectra demonstrated strong intermolecular hydrogen bonds between the molecules of Chitosan and PVA. Furthermore, cell cultures demonstrate that both PAV and chitosan have good biocompatibility and are non-toxic.
Investigation of Microstructure, Electrical and Optical Properties of WO3 Film by RF Magnetron Sputtering with Ar/H2
Authors: Lee Chao Te , Chiu Po Kai , Hsiao C.N. , Huang C.L. , Chuang Tao Lian , Hua Chen Yu
Published: August 2010

WO3 thin film was prepared on glass substrate at room temperature by RF magnetron sputtering deposition with hybrid (Ar+2.5% H2) gas. Effects of RF power on the microstructure, electrical and optical properties of WO3 films are investigated by field emission scanning electron microscopy, X-ray diffraction, Hall measurement and spectrometer. X-ray diffraction analysis reveals that all of the films are amorphous. The minimum resistivity of the WO3 film prepared with RF 70W is 5.74 × 10-3 -cm. The average transmittance in the visible region was decreased with increased RF power from 50W to 150W. The average transmittance was lower than 15% with RF 50W. The electrical and optical mechanisms have been explained in terms of composition and film thickness were changed with RF power.
Investigations on a Smart Nano-Energy Absorption System
Authors: Suciu Claudio Valentin
Published: August 2010

In this work, a smart nano- energy absorption system (nano-EAS) based on the liquid penetration/exudation in/from lyophobic nanoporous solids is proposed and its characteristics are theoretically and experimentally investigated. Damping properties of such smart nano-EAS can be reversibly, rapidly and significantly changed in a controlled fashion by external stimuli such as pressure, electric or magnetic fields, etc. Desired changes of the damping properties are induced by controlled variation of the surface tension of the liquid and/or the associated lyophobic solid, and/or by adjustment of the size of the nanopores. Variation patterns of the energy loss versus the applied pressure and the fluctuation rate of the pore radius are illustrated. Then, sensitivity of the proposed smart nano-EAS is evaluated.
Magnetic Circuit Simulation for Magnetorheological (MR) Fluids Testing Rig in Squeeze Mode
Authors: Ismail Izwan , Mazlan Saiful Amri , Olabi Abdul Ghani
Published: August 2010

In this study, a testing rig in squeeze was designed and developed with the ability to conduct various tests especially for quasi-static squeezing at different values of magnetic field strength. Finite Element Method Magnetics (FEMM) was utilized to simulate the magnetic field distribution and magnetic flux lines generation from electromagnetic coil to the testing rig. Tests were conducted with two types of MR fluid. MRF-132DG was used to obtain the behaviour of MR fluid, while synthesized epoxy-based MR fluid was used for investigating the magnetic field distribution with regards to particle chains arrangement. Simulation results of the rig design showed that the magnetic flux density was well distributed across the tested materials. Magnetic flux lines were aligned with force direction to perform squeeze tests. Preliminary experimental results showed that stress-strain pattern of MR fluids were in agreement with previous results. The epoxy-based MR samples produced excellent metallographic samples for carbonyl iron particles distributions and particle chain structures investigation.
Application of a Case-Based Process Expert System for NC Camshaft Grinding
Authors: Deng Zhao Hui , Cao De Fang , Zhang Xiao Hong , Tang Hao
Published: August 2010

In order to solve the problem that selecting process parameters is difficult and inefficient in NC camshaft grinding, a case-based process expert system is presented, which takes frame method to present cases and utilizes case-based reasoning as the core mechanism of system. One of the typical cases of NC camshaft grinding which are stored in the case base of expert system is composed of three parts including description, solution and evaluation. The expert system generates a new case description according to the characteristics of camshaft to be processed, then forms an evaluation parameter from the similarity and the confidence. In the end, process intelligent matching is obtained by applying the system.
Ultrasonic Vibration Grinding Test of Composite Ceramics Based on the Nonlocal Theory
Authors: Zhao Bo , Xie Ping , Zhao Chong Yang
Published: August 2010

The effects of ultrasonic frequency on the grinding force and surface quality were analyzed from the grinding experiment on ZTA nano-composite ceramics. The results indicate that, in the same parameters, ultrasonic normal grinding force is about 65 to 85 percents of the ordinary grinding condition, and the surface quality is better than that of ordinary grinding condition, as the frequency increasing, this trend will be more evident. The reasons for it were also discussed from microscopic and the nonlocal theory in this paper.
Development of Media for Low Pressure Abrasive Flow Machining
Authors: Fong Weng Seng , Wan Yee Ming , Butler David Lee
Published: August 2010

Abrasive flow machining (AFM) has become one of the more attractive finishing processes used in applications such as deburring, recast layer removal, radiusing as well as for polishing. Recently, there has been renewed interest in developing low cost/ low pressure modular AFM systems and media. The media which contains the abrasive particles is the key element in ensuring efficient material removal and a good surface finish. In this paper, the authors will present their work on the development and characterization of a new abrasive media formulation.
A Study on the Spiral Polishing of the Inner Wall of Stainless Bores
Authors: Chen Wei Chan , Yan Biing Hwa , Lee Hsin Min
Published: August 2010

This study investigates a spiral polishing mechanism in polishing the inner wall of stainless bore with the mixture grinding material of silicon carbide and polystyrene. The delicate polishing process is verified to be more efficient, cost-saving, and environment friendly than traditional processes. Varied sets of polishing parameters, including SiC grain size, SiC weight, polystyrene(PS) weight, viscosity of silicon oil, revolution speed of the driving screw, and machining time, are examined through the Taguchi Methods for optimum polishing effects. Impacts of different combinations of the six polishing parameters on surface roughness and texture are probed into and analyzed in the process of the experiment.
The findings suggest that with the increase of time, the fluidity and stickiness of the abrasive medium improve, resulting in a finer polished surface within delicate spiral polishing process. It appears that significant differences are observed through the use of a mixture of 60 grams of SiC (with size of 7 μm) and 70 grams of polystyrene, silicon oil of 1000 mm2/s viscosity under the speed of 3500 rpm screw revolution speed for 30-minute machining time, improving the surface roughness from 0.90 μm to 0.158 μm Ra. The finding thus lends support to the effect of spiral polishing mechanism, which can be further developed.
Study on Tool Life by Breakage in Micro Endmilling
Authors: Horiuchi Osamu , Ma Bo Xiao , Nomura Mitsuyoshi , Shibata Takayuki , Murakami Yoshihiko , Masuda Masami
Published: August 2010

To obtain some knowledge to predict the tool life caused by breakage, a series of slotting experiments was performed at various feed rates for high carbon steel by using coated carbide square end mills of 0.5mm in diameter. The main results obtained are as follows, (1) There found a possibility to obtain an optimum feed rate for the maximum slotting distance. (2) Lower feed rate caused chatter but higher feed rate rarely caused chatter. (3) A newly defined cumulative damage seems to be useful in some extent to predict tool life by monitoring cutting force.
A Study of Ultrasonically Assisted Fly Cutting for High Precision Machining Hard Brittle Materials
Authors: Hara Keisuke , Isobe Hiromi , Chiba Shuichi , Abe Keiko
Published: August 2010

This paper describes ultrasonically assisted fly cutting for finishing advanced ceramics for hot-press dies used to fabricate glass lenses. Fly cutting can perform shallow machining, which realizes ductile-mode cutting of hard, brittle materials. Ultrasonically assisted machining can increase the critical cutting depth (i.e., the maximum cutting depth for ductile-mode machining of a surface). The technique proposed in this paper combines both techniques and enables precise finishing of advanced ceramics at a high machining efficiency. Ultrasonic assisted fly cutting was found to reduce tool fracture and improve the finished surface quality compared with conventional fly cutting.
Wafer Polishing Process with Signal Analysis and Monitoring for Optimum Condition of Machining
Authors: Lee Jung Taik , Lee Eun Sang , Won Jong Koo , Choi Hon Jong
Published: August 2010

The polishing process of a silicon wafer is a critical factor in the fabrication of semiconductor. Because a globally planar and mirror-like wafer surface are achieved in this process. The surface roughness in the wafer depends on the surface properties of the carrier head unit along with other machining conditions such as working velocity, polishing pad, temperature, down-force, etc. In this paper, the wafer surface is investigated according to several parameters and experimental data. Experiments were performed to observe the down-force and temperature when the wafer carrier head unit was pressed down onto the polishing pad. A loadcell was employed to obtain the signal of the applied pressure against the polishing pad. Also, working temperature was detected using an infrared sensor. To study on the optimum conditions of machining, monitoring system is coded in Ch and the results of experiment present data using Ch.
Study on Chemical Mechanical Polishing with Ultrasonic Vibration
Authors: Tso Pei Lum , Chang Yao Cheng
Published: August 2010

Chemical Mechanical Polishing(CMP) is currently the most effective planarization method used in the semiconductor industry. Because of the continuous improvement of the wafer size and line width, the CMP process must be promoted and improved. Many studies have been undertaken to try and achieve both a high material remval rate (MRR) while maintaing a high surface quality of silicon wafer, however up until this point it appears that the two objectives are mutually exclusive. In this paper, an innovative method which integrated ultrasonic vibration assisted machining and CMP (UCMP) has been developed. With the use of ultrasonic vibration, the CMP efficiency and the quality of ploished suface improves considerably as shown in this paper. The basic principle effects of ultrasonic vibration are further illustrated and the experiments had been done to demostrate the proper procedure. The results showed that UCMP achieves a higher material removal rate (MRR) and better surface quality at the same time.
Estimation of Heat Transfer Coefficients in Dry and Cold-Air Cutting
Authors: Jiang Feng , Li Jian Feng , Sun Jie , Zhang Song , Yan Lan
Published: August 2010

For the analysis of cooling effect, the cutting inserts were heated to 900°C and then exposed in the room-air and cold-air with different pressure respectively. The temperature variation were recorded by infra-red (IR) pyrometer. The temperature-dependent global heat transfer coefficients were estimated by the theoretical analysis and experimental data. The finite element analysis (FEA) was employed to simulate the cooling process and modify the estimated heat transfer coefficients. The heat transfer coefficients decreased from 55.1 W/m2•°C (800°C) to 9.32 W/m2•°C (350°C) in the natural cooling and approximately 300 W/m2•°C (600°C) to 60 W/m2•°C (300°C) in the cold-air cooling. Cold-air cooling greatly increased the heat transfer coefficients, but it seemed the air pressure had little pressure on the heat transfer coefficients.
Effects of Cutting Fluid with Nano Particles on the Grinding of Titanium Alloys
Authors: Liao Yunn Shiuan , Yu Y.P. , Chang C.H.
Published: August 2010

The use of cutting fluid containing nano particles in wet grinding and MQL grinding of Ti-6A1-4V is studied. For comparison purpose, experiments by applying the general purpose water-based cutting fluid are also conducted. The loading of the grinding wheel and morphology of the ground surface are observed, and the grinding forces and roughness of the ground surface are measured for analysis. It is found that the use of cutting fluid containing nano particles results in less loading of the wheel and better ground surface as compared with those with the use of the general purpose water-based cutting fluid because of smaller grinding forces and coefficient of friction originated from “lotus effect” of nano particles. MQL leads to better results than wet grinding. This is attributed to the possibility of more nano particles to effectively reach the grinding zone by the assistance of the high pressure air of MQL, which in turns enhances the functions of nano particles in alleviating wheel loading and decreasing coefficient of friction. Based on the experimental results, it is concluded that the use of cutting fluid containing nano particles has positive effects on grinding. Especially the MQL, not only can it achieve the best performance, it is also cost effective and environmentally attractive.
Elliptical Ultrasonic Assisted Grinding (EUAG) of Monocrystal Sapphire – Surface Formation Characteristics
Authors: Liang Zhi Qiang , Wang Xi Bin , Wu Yong Bo , Zhao Wen Xiang
Published: August 2010

This study investigates surface formation characteristics in elliptical ultrasonic assisted grinding (EUAG) of monocrystal sapphire. During EUAG process, the workpiece is imposed to ultrasonically vibrate in two directions, i.e., vertical and parallel to work-surface, by using an elliptical ultrasonic vibrator. In our previous work, the vibrator has been produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body. When two alternating current voltages with a phase difference are applied to the PZT at the same frequency that is close to the resonant frequency of the longitudinal and bending mode of the vibrator, two dimensional ultrasonic vibrations are generated simultaneously, resulting in an elliptical motion on the end face of the vibrator. In this paper, to clarify the work-surface formation characteristics in EUAG of sapphire material, grinding experiments are carried out involving sapphire substrate. In experiments, work-surface roughness is measured, and the ground work-surface morphology is examined by scanning electron microscope (SEM). The experimental results are summarized as: (1) Compared with conventional grinding (CG), the elliptical vibration leads to a decrease of surface roughness up to 25% in EUAG; (2) The surface roughness has a monotonously increasing trend with the increasing wheel depth of cut in both EUAG and CG, but has little variation with the worktable feed rate. As the wheel speed increases, the surface roughness decreases until it reaches a minimum, and then increases in a monotonous trend in both EUAG and CG; (3) The surface quality in EUAG has a significant improvement, and it is prone to achieve the ductile regime grinding of sapphire compared with CG. These indicate that the elliptical ultrasonic assisted grinding is an efficient technique for high performance machining of monocrystal sapphire.
High-Integrity Finishing of 4H-SiC (0001) by Plasma-Assisted Polishing
Authors: Yamamura Kazuya , Takiguchi Tatsuya , Ueda Masaki , Hattori Azusa N. , Zettsu Nobuyuki
Published: August 2010

A novel machining method combined with the irradiation of atmospheric pressure plasma was proposed for the finishing of difficult-to-machine materials. The irradiation of helium-based water vapor plasma efficiently oxidized the surface of single-crystal 4H-SiC (0001), and a ball-on-disc test using an alumina ceramic ball revealed that the wear rate of SiC, the surface of which was modified by the irradiation of water vapor plasma, is 20-fold higher than that of the surface without plasma irradiation. Plasma-assisted polishing using CeO2 abrasives enabled us to improve the surface roughness of SiC without introducing crystallographical subsurface damage, and a scratch-free surface with a roughness of less than 0.3 nm rms was obtained.
Polyline Dwell Time Algorithm for Every Type of Tool Path for Ultrasonic-Magnetorheological Combined Finishing
Authors: Zhang Fei Hu , Yu Xing Bin , Zhang Yong , Lin Yong Yong
Published: August 2010

Ultrasonic- magnetorheological combined finishing (UMC) is a new technique for the ultraprecision machining of aspheric surfaces, especially for high quality workpieces with small curvature radius concave surfaces. According to the characteristics of UMC finishing, material removal model has been developed. Several types of tool path planning algorithm have been discussed. Two kinds of polyline dwell time algorithm are presented. Polyline Dwell time algorithm based on two-dimensional discrete convolution is a new dwell time algorithm, and the dwell time on the endpoints which compose the tool path can be solved by the algorithm directly. Every polyline dwell time is the mean value of dwell time of two endpoints, therefore, the polyline dwell time of every type of tool path can be solved efficiently by the algorithm. The simulation of two dwell time algorithms has been conducted with same removal function and original error distribution, and the pv convergence rate is improved from 0.939 to 0.973 by using new algorithm. Figure error PV values reduced to 29.4 nm from 1.67μm after UMC finishing. The efficiency of the polyline dwell algorithm is proved by computer simulation and experimental results.
Odor Suppression of Putrid Water-Soluble Coolant Using Home Ion Generator
Authors: Ninomiya Shinichi , Iwai Manabu , Takano Kazuyoshi , Shimizu Toshiharu , Suzuki Kiyoshi
Published: August 2010

This paper deals with a technique to easily suppress bad odor of water-soluble coolant (working fluid) by using a commercially available ion generator for home use. At the shop floor, water-soluble coolant is in heavy use, where putrid bad odor is apt to be generated from water since over 95% of the coolant component is water, leading to a short life of the coolant. Expecting an effect of suppressing putrid odor of water-soluble coolant, application of ion mixed air using an ion generator for house use was examined. As a result, bubbling with ion mixed air could achieve a drastic suppression of a bad odor generated from putrid water-soluble coolant, compared to a bubbling with air only. In addition, it was confirmed that by discharging ions into a machine emitting a bad odor, the odor level decreases drastically. From these results, a machine having an ion generator built-in can be proposed as an environmentally friendly machine tool.
Analysis of Super-High Speed Point Grinding Forces
Authors: Gong Ya Dong , Qiu Jian , Liu Yue Ming , Cheng Jun
Published: August 2010

Super high-speed point grinding is a good performance grinding with high surface quality due to its low force. To model point grinding forces including swivel angle formed by tilting wheel to the horizontal workpiece axis seems necessary. In this research, a point grinding force model was present, and the point grinding forces are influenced by factors such as grinding depth, wheel velocity, swivel angle as well as equivalent diameter. And then some experimental tests are carried out. It is found that the experimental data was in good agreement with theoretical model.
Fabrication of Small Polishing Tool by Using Electrophoresis Phenomenon
Authors: Natsu Wataru , Miyata Takeshi
Published: August 2010

In this study, a method is proposed to fabricate the polishing tool with an elastic membrane in thickness of 10 to 120μm, by using the electrophoresis phenomenon. The controllability of the membrane thickness with the applied voltage, processing time and the solution concentration are investigated experimentally. It is found that the thickness can be controlled by the applied voltage and processing time. Moreover, the polishing characteristics with the fabricated tool is examined and compared with the conventional tool. It is found that the polishing tool fabricated with the proposed method achieves the same characteristics as the conventional tool and the tool life is long enough for the practical use.
Simulation Study of Sliding Control for Constant Polishing Force Using an Innovative Sphere-Like Polishing Tool on a Machining Center
Authors: Wahjudi Arif , Shiou Fang Jung
Published: August 2010

This study proposes an innovative sphere-like tool for polishing process in the machining center. It can be applied not only z-axis rotation but also spinning rotation so that multidirectional polishing can be performed simultaneously. One of important polishing parameters is polishing force. It should be constant to prevent over or under polishing. In this paper, sliding control theory is proposed to achieve constant polishing force. Polishing process was modeled as a single degree of freedom of mechanical system including mass, spring, and damper. Control law has been determined based on polishing process model using sliding surface equation. Based on this control law, single and multi desired polishing force simulations were conducted. From the simulation results, it can be shown that the procedure to design control law has effective performance.
On the Technologies of Electrochemical Mechanical Finishing
Authors: Pang Gui Bing , Adayi Xieeryazidan , Xu Wen Ji , Peng Yan Ping , Zhou J.J.
Published: August 2010

The service properties and lives of mechanical parts and components are closely related to their surface quality and precision, and many of the frictional surfaces are required to be finished thereby improving the surface quality and precision. In electrochemical mechanical finishing (ECMF) processes, the surfaces of metal parts are removed through the electrochemical anodic dissolution to obtain the desirable dimensions and surface finish. ECMF is characterized by the independence of the hardness of workpiece and little wear in tools. As a result, it has received more and more attention in the research area of polishing and finishing for mechanical parts. This article reviews the practical works in ECMF technologies from the aspects of surface quality and precision characteristics. Not only excellent surface quality but also high precision dimensions of parts can be obtained with ECMF. It has wide applications in machining precision mechanical parts and components.
A Study of the Diamond Tools for Grinding Polycrystalline Diamond
Authors: Luo Shenq Yih , Ho J.K. , Tsai Ming Yi , Liu Yi Xian , Chen William
Published: August 2010

The purpose of this paper was to investigate the grinding performance of two types of cobalt and vitrified bond diamond tools produced by the hot press for the vertical flat grinding polycrystalline diamond. The worn diamond type and the diamond protrusion observed by the toolmaker or SEM after grinding under two different feed rates of 1 and 5 mm/min and the depth of cut of 2 µm with total depth of 10µm were studied. In addition, the grinding efficiency and the workpiece surface roughness produced were analyzed as well. The experiment results showed that when the feed rate of 1 mm/min during the flat grinding PCD was used, a lower percentage of the good diamond, a higher percentage of flat diamond and pulled-out hole on the worn surface of the cobalt bond diamond tool were obtained. For the vitrified bond diamond tool, the good diamond produced showed a higher percentage and flat grit and pulled-out hole displayed a relatively lower percentage. This may be due to the result of the relatively moderate strength and grit retention of the vitrified bond. Furthermore, the diamond protrusion and the grinding efficiency produced for the vitrified bond diamond tool were better than those for the cobalt bond tool. And the PCD surface roughness obtained was better as well.
Complex Grinding Assisted with Electrical Discharge Machining for Electrically Conductive PCD
Authors: Iwai Manabu , Ninomiya Shinichi , Sugino Gaku , Suzuki Kiyoshi
Published: August 2010

A new PCD material named EC-PCD (Electrically conductive polycrystalline composite diamond), which consists of electrically conductive diamond grits, has recently been developed. This paper deals with an investigation of a complex grinding assisted with electrical discharge machining (EDM) to realize high efficiency, low and stable grinding force and low wheel wear for the new EC-PCD. The effect of complex grinding assisted with EDM is compared experimentally with the standard PCD (S-PCD). The result shows that, in the complex grinding, lower and more stable grinding force is realized thanks to the material removal action in EDM and that lower wheel wear and better surface finish are attained, just when the EC-PCD is selected as a workpiece.
The Application of Three-Dimensional Surface Parameters to Characterizing Grinding Wheel Topography
Authors: Yan Lan , Zhou Zhi Xiong , Jiang Feng , Rong Yi Ming
Published: August 2010

White light interferometer was employed to measure the surface topography of 60# and 120# alumina grinding wheel. The correlation of wheel topography and its performance was characterized through the three-dimensional (3D) surface characterization parameters of “Birmingham set”. Birmingham parameters were used to characterize the performances of grinding wheel, in items of grain density, grain shape and grain sharpness. The effects of sampling interval on the 3D surface parameters were analyzed and the optimal sampling interval was selected to calculate the 3D surface parameters.
Characterization and Performance of Monolayer Brazed Polycrystalline CBN Abrasive Tools
Authors: Ding Wen Feng , Xu Jiu Hua , Chen Z.Z. , Su Hong Hua , Fu Yu Can , Chen Y.
Published: August 2010

Brazing experiments of polycrystalline CBN abrasive grains and AISI 1045 steel matrix using 95(72Ag-28Cu)-5Ti (wt.%) filler alloy were carried out at the heating temperature of 900 °C for the dwell time of 8 min. The microstructure of the brazing interface among PCBN grain, Ag-Cu-Ti alloy and steel matrix, was characterized with optical microscope, scanning electron microscope and X-ray diffraction equipment. Grinding performance of the brazed polycrystalline CBN abrasive tools was evaluated experimentally by comparison with monocrystalline CBN counterparts. The results show that the reaction layer between polycrystalline CBN abrasive grain and Ag-Cu-Ti filler layer consists of the compounds of Ti-nitride, Ti-borides and Ti3AlN. The resultants have played an important role in terms of strong chemical joining at the grain-filler interface. The brazed abrasive tools with polycrystalline CBN grains have given higher material removal rate and longer service life than that with monocrystalline CBN ones.
A Study on Pressure Stability in Double-Sided Polishing Process
Authors: Li Wei , Jin Cheng , Hu Xiao Zhen
Published: August 2010

How to achieve the precision double-sided polishing process is a important issue for wafer manufacturing, it depends on machining condition such as machining environment, polishing speed, polishing operation mode, polishing pressure, polishing fluid etc. The key factor to the wafer surface quality is the stability of the polishing pressure. This paper analyzes the impact of double-sided polishing pressure in polishing process, using AMESim software to simulate the pressure standard deviation’s changes under diffrent polishing pressures, and carries out some experiments to identify the impact of polishing parameters (such as the ring gear ratio, polishing speed, polishing pressure) to the polishing pressure stability and the wafer surface quality.
Analysis of Surface Topography Characteristics in Electrochemical Mechanical Finishing
Authors: Wei Ze Fei , Xu Wen Ji , Pang Gui Bing , Wang Xu Yue
Published: August 2010

In this paper, surface topography characteristics of electrochemical mechanical finishing (ECMF) for steel was investigated. The scanning electron microscopy (SEM) was used to observe the surface topography. And the microcosmic geometry parameters were measured by Talysurf SLI2000. Compared with original surface, the surface topography characteristics of the workpiece machined by ECMF have been analyzed with altitude density function (ADF) and auto correlation function (ACF). The results show that there exist periodicity component in surface profile before and after finishing. The auto correlation curves of ECMF surface have a smaller average period compared with grinding surface. The low-frequency component and the mean ripple peak distance of original surface profile are obviously decreased. Furthermore, the ripples and peak density are increased, and the surface roughness Ra is decreased from 0.231μm to 0.023μm. The results indicate that surface quality, material ratio of the profile and wear resistance machined by ECMF are improved obviously.
Approaches to In-Process Measurement of Surface Roughness in Cylindrical Grinding
Authors: Tachikawa T. , Ohashi Kazuhito , Tago M. , Tsukamoto Shinya
Published: August 2010

The purpose of this study is to develop an in-process of measurement technique of surface roughness using thermoelectric effect in cylindrical grinding. The electromotive force (EMF) generates depend on the surface roughness of workpiece and the variation of workpiece temperature when the sensor with thermocouple wires rubs on the workpiece surface in grinding process. In this paper, the in-process measurement technique of surface roughness in cylindrical plunge grinding is proposed, conceiving the cancellation of the EMF caused by the variation of workpiece temperature in the sensor output. Also a new type in-process sensor was developed for high accuracy to overcome the problem which was clarified in the cancellation method of the influence of workpiece temperature at a basic sensor.
Online Measurement of the Crankshaft Crankpin Roundness Errors in the Process of Coordinate Polishing with Abrasive Tap
Authors: Xiao Gui Jian , Huang Yun , Huang Z. , Si Li Na
Published: August 2010

The roundness error is researched in the process of coordinate polishing crankshaft crankpin with abrasive belt by measuring online. A detailed study on the tracing motion equations of the measurement system is made，so the mathematical model is obtained in this paper. In order to improve the in-situ measurement precision, the two-sensor tracing roundness error separation principle is proposed under motion stage. Finally, the conclusion that the source of errors could be determined initially according to online measurement of roundness errors is obtained, and then improving the accuracy by changing processing conditions timely.
The Development of the Automatic Measurement of Straightness Using by a Ball Screw
Authors: Kono Ginsuke , Kuroda Takaharu , Daitoh Teruyoshi , Maruoka Kuniaki
Published: August 2010

Recently, the screens of TVs and computers are getting larger and larger. In accordance to that, surface plates of those, which are used during the production process, are also becoming bigger. These surface plates are required to be checked every certain period of duration. Therefore, an automatic measurement of straightness, that is highly accurate, and capable of measuring large area, is necessary. The straightness is the degree of difference from a straight line geometrically. It is one of the indexes to express machining precision. In Mechanical Engineering, the accuracy of processing side and the exactitude of the table and the surface plate, which are the bases of the processing side, decide the quality of products. There are a number of methods to measure the straightness. In this experiment, we use a straightness-measuring instrument, which moves a gauge parallel to the surface, and measure the values. Fig. 1 shows the appearance of straightness- measuring instrument. This straightness-measuring instrument is consisted of guide rail, carriage, and support blocks. During the actual measurement, the control of the carriage to connect the gauge is manually operated. This manual operation is simple, but measurement time and precision greatly depend on individual skill. In addition, measuring process requires good length of time with intensity, hence it causes the worker mental exhaustion. Therefore, if we can mechanically operate the carriage it will improve the accuracy and data collection will be easier. This research is aimed to mechanically operate the straightness-measuring instrument and measure consecutive positions in a short period of time. This report explains the design, production, and motion test of the automatic movement mechanism of the carriage.
Study of AE Signal for Tool Wear Monitoring in Micro Milling Based on LVQ Algorithm
Authors: Yen Chia Liang , Lu Ming Chyuan , Chen Jau Liang
Published: August 2010

The Acoustic Emission signal was studied in this report for tool wear monitoring in micro milling. An experiment was conducted first to collect the AE signal generated from the workpiece during cutting process for characteristic analysis, training the system model and finally testing the system performance. In the system development, Acoustic Emission (AE) signals were first transformed to the frequency domain with different feature bandwidth, and then the Learning Vector Quantization (LVQ) algorithms was adopted for classifying the tool wear condition based on the generated AE spectral features. The results show that the frequency domain signal provides the better characteristics for monitoring tool wear condition than the time domain signal. In considering the capability of the AE signal combined with LVQ algorithms, the sharp tool condition can be detected successfully. At the same time, 80% to 95% of the classification rate can be obtained in this study for the worn tool test. Moreover, the increase of the feature bandwidth improved the classification rate for the worn tool case and 95% of classification rate for the case with 10 kHz feature bandwidth.
Wear Performance Evaluation of Tungsten Carbide Taps in Blind Hole Tapping Cast Iron
Authors: Chen Ming , Zhang Xiao Hui , Han Bing , Rong Bin , Liu Gang
Published: August 2010

The engineblock and cylinderhead of automobile are usually made of cast iron, and tapping of blind holes is one of the most demanding operations. As usual, tapping is the final process for an engineblock, and the failure of taps can disable the engineblock possibly. The productivity is restricted because of the low cutting speed and poor wear resistance of high speed steel (HSS) taps. Thereby, according to the demand on high speed cutting and low tact time of modern engine production lines, several new typical special tungsten carbide taps are developed and their cutting performance are evaluated in comparison with the commercial taps. In the process of tapping blind holes in gray cast iron and ductile cast iron, several aspects are studied comparatively such as wear mechanism of the first complete and the last incomplete tooth, tap structure, wear of TiCN coating and effects of coolant on cutting performance of taps. This study indicates that straight coated taps with fewer flutes are suitable for high speed tapping of cast iron.
A Study of the Cutting Temperatures of Turning Stainless Steels with Chamfered Main Cutting Edge Nose Radius Worn Tools
Authors: Chang Chung Shin
Published: August 2010

To study the cutting forces and the carbide tip's surface temperatures of stainless steel (SUS 304) with a chamfered main cutting edge nose radius worn tools. A new cutting temperature model incorporating tool worn factor and using the variations of shear and friction plane areas occurring in tool worn situations are presented in this paper. The heat partition factor between the tip and chip is solved by using the inverse heat transfer analysis, which utilizes temperature on the carbide tip’s surface measured by infrared as the input. The tip’s carbide surface temperature is determined by finite element analysis (FEA) and compared with temperatures obtained from experimental measurements; good agreement demonstrates the proposed model.
Study on Thermal Properties of Hybrid Journal Bearing for Super High Speed Grinding Machine
Authors: Xiu Shi Chao , Gao Shi Qiang , Sun Zhi Li
Published: August 2010

As the high speed bearings, hybrid journal bearings are usually used in high and super high speed grinding machine spindle system. Since the bearing operates under high speed conditions, the excessive temperature rise of bearing is a key factor to lower the accuracy of the spindle system and limit the bearings working speed, so restrict the bearing applications. In this paper, the model of hybrid journal bearing is established to analyze the heat mechanism. In addition, the temperature field distribution for the certain hybrid journal bearing at high speed is studied by ANSYS considering the heat transfer characters between fluid and solid. The experiment of temperature for hybrid journal bearing system in super high speed grinding machine is also performed. The thermal properties and the measure for controlling temperature rise of such bearings are analyzed.
The Determination of Key Material Property in High Energy Beam Drilling
Authors: Ho Je Ee , Yen Chen Lung
Published: August 2010

In this study, a 2-D model with dimensionless analysis was proposed by discussing the roles of the active material properties in high energy beam drilling. With the assumption of small Pelect number, quasi-steady transformation and scalar analysis in this model, several dimensionless parameters had been generalized. Among these parameters, the dimensionless material property , defined as evaporation latent heat to internal energy at melting point, was proven to be the key member; which not only significantly influenced the nonlinear variation inside the work piece, but also directly determined the penetration results whose behavior showed a resemblance to the distribution of exponential function in . Further more, the maximum efficiency had been successfully estimated, and the dramatic change of drilling characteristic during the transitional energy region was also reasonably simulated. When compared with the experimental results from Allmen [1], the present model with given copper properties showed an excellent agreement on material removal rate (their relative errors were not more than 15 ％.)
Evaluating the Micromachining Rate of Nanosecond Laser with Thermal Analysis
Authors: Ho Je Ee , Young Hong Tsu
Published: August 2010

For optical micro- machinery processing, nanosecond laser possess a special advantage in using it as a fabrication method of smaller hole subjected to the minimum thermal distortion. Thus it has become an effective and powerful tool widely used in drilling, cutting and welding process for micro-manufacturing field. To estimate the working performance of pulsed laser, an auxiliary method in numerical skill or semi-empirical technology is usually utilized, where the important parameters including energy intensity, duration and wavelength of laser beam will be taken into account. Nevertheless, several troubles, the unstable numerical iteration for phase change and precise calibration of sensor required in the measuring process, seem to be still inevitable, and which easily makes the numerical calculation become more complicated, even the global ablating behavior will be lost. To compensate the inadequacy mentioned above, an analytic model of optical ablation for pulsed laser, based on the evaporation effect responsible for penetration mechanism, is then derived in this study. Here the penetrating behavior, during the micro-machining process, can be clearly examined with the consideration of plasma absorption. After compared with experimental results made by Chen and Schmidt for copper drilling and steel ablation for Tim, a better agreement of analytic results identifies the accessibility of proposed model which also contributes to the future investigation on pico-or femto- laser material processing.
Optimal Parameter Design in Flip Chip Micro-Machining Process for Solder Residue by Using Design of Experiments Approach
Authors: Kuo Jian Long , Kuo Chun Cheng
Published: August 2010

Since the solder residue is essential in the semiconductor manufacturing process, it has great impact on the flip chip quality considerably. This paper intends to improve the flip chip quality and try to obtain an optimal solution for the system parameters in the flip chip manufacturing process. The SMT manufacturing process is studied for discussion. The amount of solder and the size of solder are selected as the two quality properties. During the flux cleaning process, many solders are left on the passive component side. The balling might flow into the chip. It will cause the bump short in the chip which will affect the quality of the flip chip severely. In this paper, response surface method is adopted as the design of experiments. The objective function and subjective constrained conditions are defined to formulate the optimization problem. The confirmation experimental results are also provided to prove the validity. It is believed that the optimization results are helpful to the improvement of the semiconductor manufacturing process.
Analysis of Mechanical Property of Crystal CaF2 and Effects of Tool Rake Angle on Ductile Machining Process
Authors: Chen Ming Jun , Jiang Wen Bin
Published: August 2010

Indentations on the three main crystallographic planes (100), (110), and(111) of CaF2 were analyzed. Appropriate material parameters were obtained by experimental load-displacement curves. The results show a value in the range of 70–110 MPa for the initial shear yield strength. The submicron-level orthogonal cutting process of CaF2 had been investigated by the finite element approach, and the effects of tool rake angle on cutting stress and chip formation were investigated. The results indicate that increasing the tool rake angle causes a significant increase in stress and a decrease in chip thickness. The simulation results from the present study show the optimal tool rake angle to the ultra-precision cutting of CaF2 is -20°.
Micro Abrasive Jet Machining of Silicon Carbide (SiC) Fiber Reinforced Ceramic Matrix Composite
Authors: Chou Ke Ju , Usami Hatsuhiko , Enomoto Kazuki
Published: August 2010

Abesive jet machining (AJM) of silicon carbide fiber reinforced silicon carbide ceramic composite (SiC/SiC CMC) was carried out with various size of silicon carbide fine abresives. A micro indentation experiment was connected to evaluate of maerial removal mechanism by the particle impact. Results showed that the machine rate was different depending on the particle size and that inteface fracture (debonding) has influenced on the material removal mechanim. Relationship between structure scale of the SiC/SiC CMC and the impact media size was discussed.
Thermal Transport in the Copper Powders with Nanometer and Micrometer Particles
Authors: Ho Ching Yen , Tsai Yu Hsiang , Sui Feng Ming
Published: August 2010

This paper investigates effects of particle size on heat transfer in copper powders. The understanding for thermal properties of the powder is advantageous to the advancement of the processing technologies such as laser cladding, laser sintering, powder metallurgy and its other applications. Nanosized particles possess characteristic physical and chemical properties different from those of bulk materials due to the confinement of electrons, excitons, and photons into small volumes. Therefore it is valuable to discuss the thermal behaviours of powders constituted by nanometer-sized particles. The powder is wrapped up in the slender tube. One end of the slender tube filled with powder is connected to the low constant-temperature reservoir and the other end is kept at room temperature. The temperature histories at the 1cm location of the slender tube from the low constant-temperature reservoir are recorded using thermal couples. Powders of particles with the sizes 50nm and 5000nm are employed in this experiment. The results show that the thermal diffusion in the 50nm Cu powder is faster than that in the 5000nm Cu powder.