bluuebunny/crossref_metadata_2025 huggingface dataset:
Nondestructive Evaluation of Braided Carbon Fiber Composites Using High Tc SQUID
Authors: Shinyama Y. , Hatsukade Yoshimi , Tanaka Saburo , Takai Y. , Aly-Hassan M.S. , Nakai Asami , Hamada Hiroyuki
Published: August 2010

Braided carbon fiber reinforced plastics (CFRP) is one of the multifunctional materials for applications to industrial products. We applied the superconducting quantum interference devise (SQUID) nondestructive evaluation (NDE) technique with high magnetic sensitivity and spatial resolution to inspect the state of the fabric in the braided CFRP. We prepared flat braided CFRP samples with nonuniform, uniform and cut-out bundles, which were fabricated with fold biaxial (±45º) tubular fabric and epoxy resin. While injecting ac current into each sample, the diagonal magnetic field gradients dBz/dx and dBz/dy above each sample were measured by the NDE system employing a SQUID gradiometer and xy-scanning stage, and then, the current flow in each sample was visualized by the field-gradient-to-current conversion method. In the measurements, it was shown that the current flowed along the continuous bundles in the cases of nonuniform and uniform samples, and it transmitted between bundles in the case of the sample with cut-out bundles. From these results, we showed the possibility that the NDE method can be applied to the nondestructive inspection of the integrity of the textile of braided CFRP.
Synthesis and Photophysics of Two Dipolar Copolymers Containing Hole-Transporting Unit and Alq3 Unit
Authors: Luo Jian Xin , Liang Li Yan , Lu Man Geng
Published: August 2010

Two novel copolymers combining the electron-transporting group (Alq3), hole-transporting group (carbazole and phenothiazine) and chromophore had been obtained. The copolymers were characterized by 1H NMR, IR and UV-vis absorption spectrum, and exhibited good solubility in a wide range of organic solvents such as toluene, THF, chloroform, DMF and DMSO. GPC shows moderate molecular masses of the copolymers around 15000 and a narrower weight distribution (PDI≈1.4). The DSC and TGA measurements indicated that the resulting copolymers have excellent thermal stability and higher glass transition temperatures than the commonly used light-emitting conjugated polymers. The PL properties of the copolymers were investigated in solution and in the solid state. Only the Alq3 emission (520 nm) was observed at high concentration (10 g/L) or in solid state. However, with the decrease in concentration of the copolymer solution, the characteristic emission of carbazole appears. This means the energy transfer taken place in higher concentration is more efficient than in lower concentration solution.
Forced Motions of Composite Conoidal Shell Roofs with Complicated Boundary Conditions
Authors: Bakshi Kaustav , Das Hari Sadhan , Chakravorty Dipankar
Published: August 2010

An eight noded isoparametric finite element code is applied to study static bending, free and forced vibration characteristics of composite conoidal shell roofs with complicated boundary conditions which are often encountered in the industry.
Structural Damage Monitoring of a Composite Wing Using Multiple Types of Sensors
Authors: Park Chan Yik , Cho Chang Min , Jun Seung Moon
Published: August 2010

This paper outlines an ongoing SHM project called KASHMOS where the damage detection in composite wing structures using multiple sensors is investigated. The test bed is a composite UAV wing section and the ground structural tests are being performed to evaluate developed systems. Different kinds of damage modes in prearranged areas are intentionally induced. Optical fiber sensors, piezo-electric active sensors and Q-switched pulse lasers are utilized for detecting the damage and monitoring the integrity of the wing structure. Strain-based, impedance-based, and ultrasonic-wave-based damage monitoring methods are studied. Although this investigation is based on the ground tests, the operation concepts for the onboard system as well as the ground system are also considered.
Pt/Zeolite Catalyst for the Treatment of High VOC-Containing Wastewater
Authors: Hwa Mei Yin , Lin Ching Hsing , Chang Yu Jie , Lee Yao Chuan , Liu I Ray , Chang Jen Ray
Published: August 2010

Pd/SDB (Styrene Divinylbenzene Copolymer), a hydrophobic catalyst, has been used for the destruction of volatile organic compounds (VOCs) in wastewater. Although the catalysts performed well in low VOC concentrations, they were not as effective in high VOC concentrations because of the heat removal problem. On the other hand, Pt/Zeolite contains a high silica to alumina ratio, which gives it hydrophobic characteristics and allows it to endure significantly higher temperatures than Pd/SDB. Hence, they were chosen for the treatment of wastewater containing high VOC concentrations. As expected, the catalysts presented both high conversion rates and good stability maintenance. Because of their high stability and rapid regeneration, the catalysts were regarded to be promising for industrial applications. In this study, the noble metal content of Pt/Zeolite amounted to 1.5 wt.%, and that the different temperatures and pressures collocating with different weight hourly space velocity (WHSV) were used to test the VOCs conversion efficiency. The results showed that the best reduction temperature was 450°C below the temperature- programmed reduction (TPR) process. The reaction system consisted of a continuous dripping flow with a fix-bed system and proportional integral derivative (PID) temperature controller. Selected VOCs such as methanol, ethanol, propanol and formaldehyde were investigated over the catalyst. Qualitative and quantitative analysis of the reagents and the potential organic intermediates was determined using gas chromatography with a flame ionization detector (FID). The experimental results indicated that the reaction rate is inversely proportional to the molecular weight for the compounds with the same functional group. For the same molecular weight, aldehyde is easier to destroy than alcohol. Ethanol and propanol, atypical products of incomplete oxidation of alcohols, were detected in the reaction gas. To minimize the energy consumption, we preferred liquid phase reaction since the heat of reaction could maintain the reaction temperature.
Deployable Process Analysis of Packaged SMP Sandwich Beam
Authors: Li Zheng Fa , Wang Zheng Dao
Published: August 2010

Shape memory polymers own many advantages compared with traditional shape memory alloys or ceramics. In order to improve their shape recovery stress and realize a stable recovery response during the deployable process, the structure of SMP sandwich beam composed of two metallic skin and one SMP core is considered. The recovery behaviors of pure SMP and SMP beams reinforced by one-layer metallic skin are also discussed for comparison. The results confirm that the deployable properties of SMP matrix can be significantly improved by using sandwich structure.
Fracture Characterization of TiAl Matrix Composites by Addition of Fluoride Solid Lubricants
Authors: Yang Li Ying , Wang Shou Ren , Wang Yan Jun , Zhu Bo , Hou Lin
Published: August 2010

The fracture characterization of Ti–48Al–2Nb-2Cr composites (TANC) with addition of different weight contents of fluoride solid lubricants (LiF, NaF, CaF2 and 38%CaF2-62%BaF2 eutectic solid lubricant (BC) ) were evaluated in the paper. The fracture toughness of composites with different content of fluoride solid lubricants is discussed. The TANC composites with 0-5 wt.% solid lubricant exhibit higher fracture toughness. It can be seen that additions of all fluoride solid lubricants to TANC matrix result in decrease in fracture toughness expect for additions of 5% of that. By adding 5 wt.% BC the fracture toughness of the TANC composites exhibited a maximum value of 12.2MPa m1/2; by addition of 5%CaF2, 11.4 MPa m1/2; 5%LiF, 10.8 MPa m1/2 while 5%NaF, 11.1 MPa m1/2. However, with further increasing of fluoride solid lubricants contents it showed a downward trend. By adding 20 wt.% BC the fracture toughness of the TANC composites exhibited a maximum value of 8.6 MPa m1/2; by addition of 20%CaF2, 8.1 MPa m1/2; 20%LiF, 8.3 MPa m1/2 while 5%NaF, 7.9 MPa m1/2.
Surface Roughness and Morphology of Titanium Plate Ground with Fixed and Loose Brown Alumina Abrasives
Authors: Han Quan Li , Zhang Wen Ming
Published: August 2010

Titanium is a metal material which has many excellent properties; it has been widely used in many fields. In this paper, plane abrasive machining is carried out for Titanium plate. The surface roughness and morphology of Ti-plate is compared after fixed and loose abrasive machining. The experiment proved that the drop magnitude of Ra in loose abrasives machining is great larger than that in fixed abrasive when grit size is nearly equal, and the improvement of surface defect such as some directional marks, deep scratch and bits in loose abrasives machining is rapider and quicker than that in fixed abrasives during same machining time. The results of experiments indicts that loose abrasive machining is better than fixed abrasive in reducing surface roughness and improving surface morphology, since the higher density of active abrasives and machining force uniformity.
Study on the Subsurface Damage Distribution of the Silicon Wafer Ground by Diamond Wheel
Authors: Gao Shang , Kang Ren Ke , Guo Dong Ming , Huang Quan Sheng
Published: August 2010

Using the cross-section angle polishing microscopy, the subsurface damage of the silicon wafers (100) ground by the diamond wheels with different grain size were investigated, and subsurface damage distributions in different crystal orientations and radial locations of the silicon wafers (100) were analyzed. The experiment results showed that the grain size of diamond wheel has great influence on the subsurface damage depth of the ground wafer. On the ground wafer without spark-out process, the subsurface damage depth increased along the radical direction from the centre to the edge and the subsurface damage depth in <110> crystal orientation was larger than that in <100> crystal orientation; but on the ground wafer with spark-out process, the subsurface damage depth in different crystal orientations and radial locations become uniform.
Investigation of Grinding Process Simulation
Authors: Yu Tian Biao , Zhang Jing Qiang , Guan Peng , Wang Wan Shan
Published: August 2010

Computer simulation is an important method to research the grinding mechanism and optimize the grinding process parameters. Especially in recent years as the development of computer calculation speed, the improvement of computer graphics theory and the gradual maturity of artificial intelligence technology, experts and scholars whose research subject related grinding had done a lot of work on grinding simulation. This paper describes the main contents grinding of the grinding simulation research work made in recent years. Include some of the key research results of the present grinding simulation, the major difficulties in grinding simulation and the research trends are summarized in this paper.
Fabrication of a Spherical Silicon Solar Cell Module
Authors: Cho Un Chung
Published: August 2010

Spherical silicon balls are applied to photovoltaic energy conversion. Silicon balls are produced by droplet spray method as well as abrasive machining of a single crystalline silicon wafer. A reflective mirror is used to maximize the solar cell efficiency. It is demonstrated the solar cell efficiency depends on the crystalline structure of silicon balls and the mirror in the module.
Study on Surface Residual Stress of Nano-Zirconia Toughened Alumina Ceramics under Two-Dimentional Ultrasonic Vibration Assisted Grinding
Authors: Yan Yan Yan , Zhao Bo , Liu Jun Li
Published: August 2010

Based on good processing property of two-dimentional ultrasonic vibration assisted grinding (TUVAG), the precision finishing of nano-zirconia toughened alumina ceramics (nano-ZTA) is carried out. According to theoretical analysis, TUVAG may obtain higher machining efficiency and better surface quality. Especially, experimental results show it may obtain the compressive stress in the finished surface of nano-ZTA that may restrain the expansion of surface microcrack, and surface residual stress of nano-ZTA under TUVAG differs from that under diamond grinding, and TUVAG may obtain the better surface quality of nano-ZTA than diamond grinding, as is characterized by scanning electronic microscope (SEM). As a result, it is good for TUVAG as a kind of processing method for nano-ZTA.
Experimental Investigation on High-Speed Grinding of 40Cr Steel with Vitrified CBN Grinding Wheel
Authors: Yu Jian Wu , Chen Tao , Shang Zhen Tao , Sheng Xiao Min , Xie Gui Zhi
Published: August 2010

This paper focuses on experimental investigation on high speed grinding of 40 Cr steel with vitrified CBN grinding wheel, the effect of grinding process parameters, such as grinding speed, depth of cut, and feed rate, on the grinding force and surface roughness are analyzed The experimental results reveal that the grinding force decreases with higher grinding speed and increases with the addition of depth of cut or feed rate, and the surface roughness is satisfactory in high speed grinding.
Mechanical Characterization of Lapping Plate Materials in Diamond Charging Process
Authors: Tanaka Hideaki , Chiba Hiromu , Yoshikawa Takehisa , Iwatsuka K. , Maeda Yukio
Published: August 2010

In the lapping of magnetic heads and other electronic components composed of multiple materials, differences in the processing characteristics of the composite materials result in “residual steps” forming on the surface at composite interfaces. Residual step heights have been reduced to as little as a few nanometers. We investigated using fine abrasives in fixed abrasive lapping for this purpose, which requires highly secure, high-density embedding of the abrasives on the lapping plate. To this end, we modeled the abrasive embedding process and investigated the relationship between the mechanical properties of the lapping plate and the retention of the abrasive, to determine the direction of further research and development. The results of this investigation revealed a correlation between the work hardening in the plate and the resulting abrasive density and cutting edge height. The investigation also showed that it is possible to suppress the reduction in lapping rate that occurs during use by increasing the work hardening coefficient of the plate.
Modeling Surface Roughness and Hardness of Grinding SKD11 Steel Using Adaptive Network Based Fuzzy Inference
Authors: Chang Chih Hsiang , Tsai Jhy Cherng , Chiu Neng Hsin , Chein Rei Yu
Published: August 2010

Grinding is a commonly used process in precision machining. This paper is aimed to establish a model for predicting surface roughness and hardness with respect to grinding parameters, including wheel speed, feed rate and depth of grinding for the SKD11 molding steel. The Adaptive Network based Fuzzy Inference (ANFIS) is used to construct the grinding model that is trained by experimental data from grinding the SKD11 steel. Test experiments are then conducted to verify the model. Results from the test experiments showed that the average error between surface roughness predicted by the model and the measured data is 3.94%. The average different of the hardness between the measured data and that predicted by the model is less than 0.06%. It verifies that the model can be used to predict surface roughness and hardness for different grinding parameters.
Influences of Characteristics of Large Particle on the ‘Trap’ Effect of Semi-Fixed Abrasive Tool
Authors: Lv Bing Hai , Yuan Ju Long , Deng Qian Fa , Wang Zhi Wei
Published: August 2010

‘Trap’ effect of the newly developed semi-fixed abrasive tool (SFAT) plays key role in decreasing the surface damages of advanced ceramics caused by the undesirable large particles emerging in machining area. Influences of characteristics of the large particle, such as size, shape and concentration, on the ‘trap’ effect of SFAT are studied with Particle Flow Code (PFC) simulation and lapping experiments. A normalized normal force is defined to evaluate the ‘trap’ effect in PFC simulation, and surface roughness is taken as an indicator in lapping experiments. The results show that the change of surface roughness is according to the one of normalized normal force. Bigger normalized normal force is better for ‘trap’ effect and surface roughness. ‘Trap’ effect works well when the large particle is in small size, sharp shape, and low concentration. In this study, the followed characteristics of the large particle are good for ‘trap’ effect of SFAT made of 1000# SiC abrasive: size <17µm, corner angle < 60°, and concentration <18 particles per mm2.
Study on the Cutting Performance of HFCVD Diamond Coated Silicon Nitride Inserts in Dry Turning Aluminum Silicon Alloy
Authors: Sun Fang Hong , Shen Bin , Yang Guo Dong
Published: August 2010

To evaluate the cutting performance of CVD diamond coated silicon nitride insert, two kinds of CVD diamond films, namely microcrystalline diamond (MCD) and composite diamond films, are deposited on silicon nitride (Si3N4) inserts using the hot filament chemical vapor deposition (HFCVD) method. The characterization of as-deposited diamond films is conducted using the scanning electron microscope (SEM), optical interferometric profiler, X –ray diffraction (XRD) and Raman spectrum. The turning tests for as-fabricated MCD and composite diamond coated insert, as well as uncoated silicon nitride insert, are performed in dry turning aluminum silicon alloy, where the cutting speed, feed rate and depth of cut are fixed as ν = 2000 r/min, f=0.1 mm/r and ap=1 mm. The results demonstrate that the main tool failure is the tool wear. As compared with the uncoated silicon nitride insert, the woking life time of the diamond coated insert can be increased by a factor of above 7.
DEM Simulation and Experimental Investigation of Silicon Carbide on Pre-Stressed Machining
Authors: Jiang Sheng Qiang , Tan Yuan Qiang , Zhang Gao Feng , Peng Rui Tao , Yang Dong Min
Published: August 2010

In this paper, the technology of pre-stressed machining suitable for ceramic materials was presented. Using the cluster method, the discrete element method (DEM) model of SiC ceramic was established to simulate the crack’s initiation and propagation in cutting processes with different pre-stress value. The scratching tests were carried out to confirm the validity of simulation. Both the DEM simulation and the experimental investigation showed that: with the increasing of pre-stress, the number of radial cracks reduced and the transverse cracks replaced the radial cracks to some extent, and also caused the material removal in the form of smaller fragments. Using pre-stressed machining can decrease the machining damage and improve the surface quality, and further prove that using DEM to simulate the machining process of ceramic materials was feasible.
Machining Schemes for Dicing Soda Lime Glass
Authors: Tsai Jhy Cherng , Chen Hong Shin
Published: August 2010

This research investigates machining schemes for dicing soda lime glass in order to reduce the damage in the processes. Ductile machining and brittle machining of glass are first analyzed based on fracture mechanics and then verified by experiments. Experiments with various machining schemes including scribing-then-breaking, direct-dicing and dicing-then-breaking processes for soda lime glass are then conducted. Experimental observations showed the following results. (i) The critical depth of cut (CDOC) for soda lime glass is between 0.4μm and 0.8μm that matches theoretical prediction, 0.78μm, based on fracture analysis. (ii) The scribing-then-breaking machining scheme results in less damage than the regular slicing process. The DOC of scribing, however, must be in the ductile-brittle region to achieve this result. (iii) Defect due to dicing on the back surface is higher than that on the front surface in one-step dicing through process. Dicing defects can be effectively reduced by decreasing the feed rate or increasing the dicing speed.
A Dishing Model for Chemical Mechanical Polishing of Plug Structures
Authors: Chang Shih Hsiang
Published: August 2010

It is well known that dishing occurring in chemical mechanical polishing of plug structures leads to considerable wafer surface non-planarity and reduces the current/charge conduction. Thus, a closed-form solution for quantitative prediction of dishing is needed. A contact-mechanics-based approach to describe the steady-state dishing occurring in chemical mechanical polishing of plug structures is presented. The model is then applied to investigate the effect of pattern geometry on dishing in details. It was shown that plug dishing strongly depends on plug size, but minimally on pattern density. In addition, the maximum value of dishing occurs at a critical pattern density for fixed pitch.
Machining Force and Modes for Si Wafer Machining with Rotational Tool
Authors: Yokemura Nobumasa , Imai Kenichiro , Hashimoto Hiroshi
Published: August 2010

In this study, basic experiments involving machining using a rotational tool were conducted with the aim of increasing the volume of material removed rate in ductile-mode machining of Si wafers. The machining surface and machining force was compared to experimentally clarify the material removal process for a single cutting edge, the critical cutting thickness tc at which occurs of cracks was set as the machining condition. Then, the three machining modes were experimentally revealed. As the result, the ductile-mode machining surface was obtained that the total depth of cut was under less than 78.5μm on ductile-brittle-mode machining.
Effects of Wafer Carrier Design on Contact Stress Uniformity in CMP
Authors: Hu Ian , Yang Tian Shiang , Chen Kuo Shen
Published: August 2010

Here we use 2-D models of fluid film lubrication and contact mechanics to calculate the contact stress and fluid (i.e., slurry) pressure distributions on the wafer–pad interface in CMP. In particular, the effective rigidity of the wafer (determined by the wafer carrier structure), the retaining ring width and its back pressure are taken to be the design parameters. The purpose is to study the synergetic effects of such parameters on the contact stress non-uniformity (NU), which directly affects the spatial non-uniformity of the material removal rate on the wafer surface. Our numerical results indicate that, for a given wafer rigidity, one may choose a particular combination of the retaining ring parameters to minimize NU. Also, the corresponding minimum NU decreases with the effective wafer rigidity, suggesting that it is beneficial to use a soft (e.g., floating-type) wafer carrier. Moreover, for a soft wafer carrier, the presence of the retaining ring also reduces NU to some extent, but the use of a multi-zone wafer-back pressure profile would be more effective in this regard.
Diamond Pad Conditioners with Oriented Polycrystalline Diamond Cubes
Authors: Chen Ying Tung , Lin Ta Wei , Liao Yunn Shiuan , Chen Jung Sheng , Lin Chao Yu , Sung James C.
Published: August 2010

Sintered polycrystalline diamond cubicles were oriented to make CMP pad conditioners. The dressing experiments demonstrated the capability of fast pad cutting and efficient removal of glazed layer that is formed by polishing wafers with slurry on dressed pad.
Mosaic Diamond Disks with Brazed Pallets for CMP
Authors: Chen Ying Tung , Yu Chen Chin , Chou Cheng Shiang , Chou Chih Chung , Pai Yang Liang , Yang Zong Qing , Cheng Mu Han , Hu Tien Chen , Sung Michael , Sung James C.
Published: August 2010

Diamond disks are indispensable for dressing CMP pads in the manufacture of semiconductors. Conventional diamond disks contain one type of diamond grits, with the aim to achieve two different functions, viz. glaze shaving and asperities grooving. Cocktail diamond disks are made by assembling brazed diamond pallets that contain different types of diamond crystals. Thus, the pad can be dressed clean, and at the same time, asperities may polish wafers fast without damaging.
Analysis and Modeling of Micro Abrasive Air Jet Cutting Aspect Ratio
Authors: Li Quan Lai , Huang Chuan Zhen , Wang Jun , Zhu Hong Tao , Liu Zeng Wen
Published: August 2010

Micro abrasive air jet machining technology is being increasingly used in the fields of micro cutting. Since the aspect ratio is a major interest characteristics of kerf in micro cutting, an experimental investigation is carried out to study the effect of cutting process parameters on the aspect ratio in this study. It is found that the aspect ratio increases with an increase in air pressure, abrasive flow rate and jet incidence angle, while decreases with an increase in nozzle traverse speed. Furthermore a predictive model for aspect ratio is developed using the dimensional analysis technique. It is shown that the model predictions are in good agreement with the experimental results. The research results may be meaningful to efficiently control the aspect ratio.
Bending of Pure Titanium Sheet to Curved Surface Shape by Laser Forming Technique
Authors: Nunobiki Masayuki , Okuda Koichi , Hourai Kousuke , Shizuka Hiroo
Published: August 2010

This paper deals with laser forming procedure to bend pure titanium sheets along arbitrary curved shape. In preliminary experiments, single straight-line bending was carried out and the relationship between bending angle and laser irradiation conditions was investigated. It was clarified that the bending angle was able to control with scanning velocity and the number of scanning passes. With use of obtained experimental formula for the bending angle, we tried to bend the Ti sheet along given parabola shape with a multi straight-line bending. The experimental result was corresponding to the target shape well. This paper proposed a laser forming procedure for curved shapes which include both convex curve and concave curves. It was confirmed that it was able to curve a titanium sheet along arbitrary curved surface with proposed method.
Microfabrication of Photosensitive Glass by Femtosecond Laser Direct Writing
Authors: Cheng C.W. , Chen J.S. , Lee P.X. , Chien C.W.
Published: August 2010

In this study, a method for the fabrication of microstructures on the surface and inside photosensitive glass (Foturan glass) by femtosecond laser-induced modification was developed. This technique was followed by heat treatment to crystallize the modified area, and the specimen was then placed in an HF acid solution for chemical etching. The fabricated microstructures were observed using scanning electron microscopy (SEM). Two examples: (a) a U-shaped microchannel and (b) an arc-type microchannel formed inside glass are presented.
An Investigation of Attachment on Electrode Surface in Dry EDM
Authors: Shue Ke Yu , Tsai Yao Yang , Chang Yo Ming
Published: August 2010

Dry Electrical discharge machining (Dry EDM), using gas as dielectric, has been developed to solve problems against environment. It has both advantages of high material removal ratio (MRR) and low relative electrode wear ratio (REWR). We investigated the effect of duty factor, peak current, and reference ratio of gap voltage on MRR and REWR of Dry EDM, respectively. Moreover, trying to prove the attachment on electrode surface could decline REWR. It is considered that melting material of work-piece was sputtered and stuck onto electrode surface, and to become a protection layer as result in low REWR. However, the attachment will be removed under the condition of high peak current and high discharge frequency. But the amount of attachment just has little change when discharge number and arc discharge ratio are both decrease.
A Review on the CMP of SiC and Sapphire Wafers
Authors: Wang Yong Guang , Zhang Liang Chi
Published: August 2010

Chemo-mechanical polishing (CMP) has been a useful method to produce superior brittle wafer surfaces. This paper reviews the CMP of silicon carbide and sapphire wafers, focusing on efficiency of the polishing rate. The effects of slurry type, slurry pH value and mixed abrasives will be discussed in detail.
Study the Rheological Properties of Abrasive Gel with Various Passageways in Abrasive Flow Machining
Authors: Cheng Ken Chuan , Chen Kuan Yu , Wang A Cheng , Lin Yan Cherng
Published: August 2010

Abrasive flow machining (AFM) is a simple and efficient method to remove recasting layers making by wire electrical discharge machining (WEDM). However, conventional AFM methods have difficulty achieving uniform roughness of an axial distribution in circular hole polishing due to limited unitary axial motion of abrasive media. Therefore, this work develops mechanism designs for different passageways to obtain multiple flowing paths of abrasive medium, whose flowing behavior enhances polishing effectiveness by increasing the abrasive surface area and radial shear forces. The motion of the abrasive medium is studied by utilizing different mold cores, which mold shapes include the circular, hollow and helical passageway. The optimum design of the passageways is then verified using CFD-ACE+ software, numerical results indicate that passageway with six helices performed better in the uniform surface roughness than others’ do. Experimental results show that roughness deviation of six helices passageway of approximately 0.100 m Ra is significantly better than those on a circular passageway of around 0.1760 m Ra. Additionally, the six helices passageway is also superior to circular passageway in reducing roughness improvement rate (RIR) by roughly 87% compared with RIR 67.7% for the circular passageway.
Processing Characteristics of Structured Lapping Films under Grinding Load Control
Authors: Higuchi Shizuichi , Sugisaki Mitsuru , Kato Hideo , Okawa Kazuya
Published: August 2010

Pyramidal structured lapping film, which has minute pyramidal structures formed by abrasive grains and adhesives on polyester films, is newly developed finishing tool[1,2]. It is said that the tool has eminent grinding characteristics, mainly, good finished surface quality because chips generated during grinding process can escape into spaces between pyramidal structures, and high grinding efficiency because new abrasive grains come out from inside of the pyramidal structures during grinding process. However, finishing characteristics of this grinding tool have not yet been fully explained.　In this research, the grinding experiments were conducted, focusing on the efficiency of grinding. The grinding forces were measured to examine the state of the surface of the tool. In addition, to improve the grinding efficiency using this tool, a method for changing the grinding load continuously while processing was used. This method was intended to enhance the effective chip generation and new abrasive grain emergence. As a result, stock removal of the workpiece was increased more than when the grinding load was kept constant. Moreover, using scanning electron microscope, this new grinding tool surface was observed, and its effectiveness was examined.
Design of Product Surface Finish via Magnetic-Assistance
Authors: Pa Pai Shan
Published: August 2010

This paper studies the performance assessment of magnetic-assistance electrochemical finishing using an effective design system and magnetic force to the electrolyte to assist the dregs discharge on zinc alloy beyond die casting by electrochemical finishing as a finish process on the freeform surface of castings. An outer shell of toy vehicle is taken for instance in the experiment. A small distance between the two magnets or large magnetic field intensity provides larger magnetic force and discharge ability. A higher current rating with magnetic-assistance can avoid the difficulty of dreg discharge, thus reducing the finish time. Pulsed direct current can slightly promote the finishing effect, but the machining time is increased. Thus the magnetic-assistance electrochemical finishing without pulsed current is recommended for the finish process. It is a great contribution that the magnetic-assistance electrochemical finishing just needs quite short to make the freeform surface of workpiece smooth and bright.
Lapping of Polycrystalline Diamond Compact (PDC)
Authors: Fang Alex , Castell Perez Elena , Puerta Gomez Alex , Zhou Song Sheng , Sowers Jason
Published: August 2010

This paper is aimed at developing an efficient process, in terms of the material removal rate (MRR), for the lapping of polycrystalline diamond compact (PDC). A carbomer based viscoelastic vehicle with a non-reversible shear-thinning property was first developed for the effective suspension of diamond grits used for lapping. The effects of key process parameters on the MRR such as lapping pressure, speed, vehicle concentration, diamond grit concentration, and vehicle flow rate have been investigated through experiments. To obtain an insight into what happened to the diamond grits during lapping, diamond abrasives were reclaimed and sieved after lapping. The grit size distributions of diamond abrasives before and after the lapping were then compared.
Identification of Brittle-Ductile Material Removal Characteristics in Ultrasonic Aided Lapping of Engineering Ceramics
Authors: Jiao Feng , Zhao Chong Yang , Zhao Bo
Published: August 2010

For the precision engineering ceramics parts, semi-ductile regime machining technologies are usually adopted to obtain the final surface. It is very important to research the brittle-ductile material removal characteristics and corresponding monitoring technology in ultrasonic aided lapping of engineering ceramics to obtain better surface quality. A series of lapping tests were carried out in the paper and the influence law of lapping parameters on the ductile percentage of ultrasonic lapped surface was achieved, which enables to off-line identify the material removal characteristics. Though the material removal characteristics can be online judged through monitoring the ratio of lapping component forces qualitatively, the monitoring effect is worse just because of lower response frequency of dynamometer and the relativity of lapping force. In this paper, a novel online monitoring technology of material removal characteristics is put forward based on AE technology. Through the wavelet package analysis of AE signals, the discrimination index and standard of material removal characteristics can be obtained. It is proved that this technology can realize online identification of the brittle-ductile material removal characteristics in ultrasonic aided lapping of engineering ceramics effectively.
Theoretical Analysis of Grinding Temperature Field for Carbon Fiber Reinforced Plastics
Authors: Gao Hang , Ma H.L. , Bao Yong Jie , Yuan H.P. , Kang Ren Ke
Published: August 2010

A three-dimensional finite difference method (FDM) model of grinding temperature field for carbon fiber reinforced plastics (CFRP) was established, based on the homogenization of the thermal properties of the CFRP material. The effect of the fiber direction on grinding temperature distribution at different workpiece velocity was numerically simulated and analyzed. It is found that the effect of the fiber direction on grinding temperature field is remarkable in lower workpiece velocity but unapparent in higher workpiece velocity due to the anisotropy of CFRP material and the velocity of moving heat source. More than 230 °C surface grinding temperature, which will badly damage CFRP performance, may be produced in dry grinding according to the simulated analysis. During grinding the heat affected zone of CFRP is about 0.22 mm in depth direction. Furthermore, experimental results are well in agreement with those of the theoretical analysis.
EDM Properties of EC-PCD Using a Copper Electrode
Authors: Ninomiya Shinichi , Iwai Manabu , Sugino Gaku , Takada Takuya , Suzuki Kiyoshi
Published: August 2010

Electrically conductive polycrystalline composite diamond (EC-PCD), which consists of electrically conductive diamond grits, has recently been developed for the purpose of providing the material with both excellent tool property and good machinability. This paper deals with an investigation of machinability of EC-PCD by EDM with a copper (Cu) electrode. As a result, it was found that the EDM speed (Material removal rate) for EC-PCD was higher than that of the standard PCD. Although the surface roughness of the standard PCD was 13µm Rzjis at set current ip=3A, the surface roughness of the EC-PCD was 5µm Rzjis at the same current condition. Furthermore, it was observed that the EC diamond particle in EC-PCD was machined by single discharge EDM. Moreover, it was confirmed that EC-PCD was able to be applied a fine discharge profiling or a making fine holes using a rotating electrode.
Using Electro-Rheological Chain Structure to Improve SKD11 Surface
Authors: Hung Mîng Chih , Tsai Yao Yang , Wang Lin
Published: August 2010

In the past half century, EDM (electrical discharge machining) is one of the most popular methods for manufacturing casting and plastic injection molds. Unlike other traditional mechanical cutting methods, EDM removes materials away by sparks, which leads to high temperature and pressure. As a result, it has no restriction to hardness because of its non-contact property. However, there will be recast layers on the surface of work-pieces and thus the surface need improved. In order to decrease the surface roughness, we added different powders into dielectric to become ERF (electrorheological fluid). By rotating spindle, the chain structures of ERF can improve surface of SKD11. The result shows that, when the gap is 100μm and electrode φ2, starch has 61% improvement rate and Al2O3 has 14.97%.
A New Polishing Pad of EVA-Adhesive-Dressed-with-SiC-Grits Polishing Face and its Applications in Silicon Wafer Polishing
Authors: Tsai Sung Lin , Huang Fuang Yuan , Yan Biing Hwa , Tsai Yao Ching
Published: August 2010

This paper presents a new polishing pad with polishing silicon surface composed of a layer of Ethylene-vinyl acetate (EVA) adhesive pad coated with SiC grits. A set of polishing parameters: coating SiC grit size, concentration of SiC grit in slurry, polishing load, polishing wheel turning speed, and absorption time of polishing pad were identified with the Taguchi Methods for optimum polishing effect in terms of roughness of polished silicon surface. A surface roughness of 0.026 μm Ra can be obtained with the following values: grit size at 1.2 μm (both coated on pad and mixed in slurry), concentration of SiC grit in slurry at 25%, polishing load at 50 gram, turning speed at 10,000 rpm, absorption time of polishing pad at 15 minutes.
Mathematical Modeling of Electrochemical Deburring
Authors: Xu Wen Ji , Wang W. , Wang Xu Yue , Pang Gui Bing
Published: August 2010

The drilling burr is taken as the research object. A mathematical model of electrochemical deburring (ECD) is established and the effects of main influencing factors, such as inter-electrode gap, applied voltage and deburring time, on burr height have been analyzed. The results show that the deburring time increases with the increase of initial burr height, inter-electrode gap, with the decrease of volume of electrochemical equivalent of the workpiece material, conductivity of electrolyte and applied voltage. The deburring time for various burr heights can be predicted by the mathematical model. The calculated results obtained from the mathematical model are approximately consistent with the experimental results. The results show that initial burr height h0=0.722mm is removed, and the fillet radius R=0.211mm is obtained.
Study on Precision Polishing of a Mini Roller Mold
Authors: Chao Choung Lii , Hsiao Ying Ching , Chou Wen Chen , Kuo Chia Wei , Lai Wen Lang , Lin Hung Yi , Ma Kung Jeng
Published: August 2010

This research aimed to design and develop a polishing system for precision polishing mini roller mold to nanometer surface finish. An experimental polishing system was built in the present study to polish nickel plated specimens with various polishing compounds. The polished specimens were subsequently examined by Alfa-step, OM and SEM for surface finish, morphology and microscopic analysis respectively. The obtained surface condition and material removal rate were correlated to the polishing parameters such as spindle speed, abrasive concentration, and abrasive grit size for the improvement of the polishing effect. Mini-rollers of 5mm in diameter, 50mm in length were successfully polished to a surface roughness better than 2nm Ra in several hours without damaging the roundness and cylindricalness using abrasive of 0.3μm, 10,000rpm polishing speed and 0.5mm gap distance between polisher and the specimen. A semi-empirical model of polishing was also developed in the study for predicting the materials removal rate.
Sharpening Mechanism Using Composite Electro-Plating In-Process Sharpening Technique
Authors: Chen Tai Jia , Lee Rong Tsong , Chiou Yuang Cherng
Published: August 2010

The in-process sharpening mechanism of the grinder during the grinding process of a CVD diamond film surface is investigated using the composite electro-plating in-process sharpening (CEPIS) technique. The bath concentration is employed to investigate the variation of coating structure deposited on the grinder. Results show that the land area ratio increases with increasing nickel chloride concentrations (NiCl2．6H2O) of the plating bath from 10 to 30 g/L, and the coating structure becomes very smooth without porous area at the nickel chloride concentration of 75 g/L. Therefore the coating structure becomes compact to hold the diamond particles rigidly. Consequently, the grinding ability of the grinder can be significantly improved, where the mirror-like surface of the CVD diamond film can be achieved.
Modeling and Simulation of 3D Surface Finish of Grinding
Authors: Sharif Ullah A.M.M. , Tamaki Junichi , Kubo Akihiko
Published: August 2010

The main body of grinding knowledge comes from the experiments done by independent investigators. If such experimental results are not made both human- and machine-comprehensible from the very beginning, then it would be difficult to reuse the results using a computerized network or any other means. In this respect, intelligent systems are needed to create human- and machine-comprehensible models of important results like 3D surface finish, cutting force, tool wear, etc. From this perspective, this paper describes a method for modeling and simulation of 3D surface finish of grinding. A human-friendly simulation tool is developed to implement the method. The simulation result is compared with the real 3D surface finish and a close correlation is found. The presented model can be integrated with the collaborative machining networks for better utilization of grinding resources using computers (e.g., condition monitoring, process planning, automation) and even using humans (e.g., effective exchange of information among peers in the research community and in the industry).
The Three-Dimensional Surface Topographic Characterisation of Diamond Grinding Wheels
Authors: Butler David Lee
Published: August 2010

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure.
One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.
Design of Digital Filters for Si Wafer Surface Profile Measurement – Noise Reduction by Lifting Scheme Wavelet Transform
Authors: Nonomura Kazutaka , Ono Masashi , Zhou Li Bo , Shimizu Jun , Ojima Hirotaka
Published: August 2010

Recently in semiconductor industry, production of ever flatter, thinner and larger silicon wafers are required to fulfill the demands of high-density packaging and cost reduction. In geometric evaluation of Si wafers, according to SEMI (Semiconductor Equipment and Materials International) standards, the required wafer flatness approaches to the 22 nanometers by year 2016 [1]. For such application, uncertainty of measured data is encountered as a severe problem because the requirement has met the limit of available instrument in terms of resolution and reliability. In order to precisely evaluate the wafer profile, it is essential to remove the noise from the measured data. Described in this paper is design and development of digital filters for denoising. In previous paper, digital filters for denoising with Haar wavelet transform are described. In this paper, the new filters by use of 2nd generation wavelet transform (lifting scheme) are proposed and show better performance of decomposition in the spatial frequency domain and amplitude domain.
Research on Machining Simulation of Ultra High-Speed Grinding Machine Tool Based on Web
Authors: Wang Wan Shan , Guan Peng , Yu Tian Biao
Published: August 2010

The future development of the manufacturing is using VR technology to make the machining simulation before the actual machining process made. The machining simulation of Ultra High-speed Grinding Machine Tool is researched in this paper. Firstly, using UG/NX software and VRML, the geometric modeling of machine tool is modeled. Secondly, through using Java and Javascript language, the operation and display of machining process of ultra high-speed grinding are realized. The main technologies include NC codes compiling, collision detection and material removal. Thirdly, the example of machining simulation using virtual ultra high-speed grinding machine tool can be obtained in the paper. Compared to other CNC machining simulation methods, the method in the paper has reality display, rich features, a good man-machine interaction, etc., and it does not rely on expensive CAD/CAM software. The system files generated by the machining simulation have the small size and can be transferred on the network easily.
A Ball-Bar Based Error Measurement Method for a RRTTT-Type Five-Axis Machine Tool
Authors: Wang Shih Ming , Yu Han Jen , Chen Da Fan
Published: August 2010

Measurement method using telescoping ball-bar that can directly determine the volumetric errors of three main types of five-axis machine tools was developed. Adopting Single Socket method, and the method following the defined two-step measurements sequence and incorporating with derived error models, can quickly determine the five degrees-of-freedom (DOF) volumetric errors of five-axis machine tools. Comparing to most of the current used measurement methods, the proposed method provides the advantages of low cost, high efficiency, easy setup, and high accuracy.