bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study on a Polishing Process of Cr12 Hardening Steel with the Embedded Combined Tools
Authors: Liu G.Y. , Guo Z.N. , Liu Jiang Wen
Published: September 2009

This paper presents a electrochemical-mechanical combined polishing progress of Cr12 hardening steel with a new kind of embedded tool. The embedded tool has been composed of two parts, the metal base acting as electrode and the inlayer with electroplating diamond grains on its outside surface which serves as mechanical grinding abrasive. The two parts are agglutinated by adhesive which can keep a good insulation of the inlayer during the mechanical process. The inter-electrode gap can be changed by altering the metal base and inlayer’s diameter. Through the investigation of numerical simulation and polishing experiment, it can be found that lower feed, reciprocate speed, longer trip of reciprocating, smaller diamond grains make better surface quality.
Study on Lapping and Constant-Pressure Grinding of Single-Crystal SiC
Authors: Yamaguchi Keishi , Touge Mutsumi , Nakano Takayuki , Watanabe Junji
Published: September 2009

Silicon carbide (SiC) single crystal has many advantages comparing with silicon single crystal, such as wide band-gap, hardness and various stable physical properties at high temperature and severe chemical environments. SiC semiconductor substrate is expected to be applied to high power devices and sensor devices in the severe environments. The polishing process under ultraviolet-ray irradiation has been developed in our laboratory to achieve the mirror-finish process of single-crystal SiC. In this paper, after the confirmation of the elastic deformation behavior of SiC single crystal using the nano-indentation tester, pre-processings of SiC by lapping and constant-pressure grinding were performed to obtain good surface without brittle fracture region. The indentation tests indicate the single-crystal SiC shows a very high elastic recovery rate. SiC substrate was processed by the lapping and the constant-pressure grinding using the constant-pressure processing to avoid the cumulative residual stock removal. As many experimental results, the constant-pressure grinding is found to be suitable for the pre-processing of SiC substrates. Additionally, it is clarified that good surface roughness on the ground surface is achieved by using a diamond wheel with the same protrusion height of abrasive grains.
Study of Three-Dimensional Polishing Using Magnetic Compound Fluid (MCF)
Authors: Sato Takashi , Wu Yong Bo , Lin Wei Min , Shimada Kunio
Published: September 2009

Magnetic compound fluid (MCF), a functional fluid responding to magnetic field, is expected for an application to many engineering fields. In this paper, the effect of magnetic fields on the polishing force and the restoring ability of the MCF are studied followed by the proposal of a new polishing technique using the MCF. Under a fluctuating magnetic field generated by a revolution of permanent magnet, the magnetic particles in the MCF show a higher particle disposition and an accumulating action compared to a static magnetic field. Thus the MCF generates the greater restoring ability but the lower polishing force compared to that under the static magnetic field. When the MCF under the fluctuating magnetic field is applied to the polishing as the flexible tool, it shows the high polishing performance. As a result, a feasibility of a new polishing technique using the MCF for a three-dimensional structure is confirmed.
Temperature Fields in Workpieces during Grinding-Hardening with Dry Air and Liquid Nitrogen as the Cooling Media
Authors: Nguyen Thai , Zhang Liang Chi
Published: September 2009

This paper presents a temperature-dependent finite element heat transfer model, incorporating a triangular moving heat source and various cooling conditions, to predict the three-dimensional temperature field in plunge surface grinding. The model was applied to analyse the grinding-hardening of quenchable steel 1045 using dry air and liquid nitrogen as the cooling media. The temperature field variation under such grinding conditions was also measured experimentally. It was found that the temperature history predicted by the model agrees well with the measured results. The model provides a fundamental study as a first step in optimisation and control of the hardened layer thickness and its compositions in grinding-hardening technology.
Study on On-Machine Deburring for Narrow Slits Made by Laser Cutting
Authors: Nunobiki Masayuki , Okuda Koichi , Kitsugi Yosuke
Published: September 2009

This paper proposed an on-machine laser deburring method for narrow slits made by laser cutting. Burrs are generally unwanted materials which remain at the cutting edge after machining operations, such as grinding, drilling, milling or turning. A cost necessary to remove burrs becomes a significant portion of the machining costs. In laser cutting, dross removal was significant problem. It is difficult to prevent completely dross from adhering in laser cutting for stainless sheets. In laser cutting for adornments, it is necessary to remove the dross and to chamfer the cutting edges in order not to injure the hand. It is difficult to remove the dross and to chamfer the edges of a narrow slit by machine work or handwork. We irradiated the defocused laser beam to the slits again for these post-processing. To control the depth and width of the removal area, we examined the relationship between the removal area and the deburring conditions. It was clarified that the width and depth of removal area can be controlled by irradiation time and energy fluence.
Simulation of Planarization of Rectangular Glass Plate Using Tool-Path-Control-Type Polishing
Authors: Yoshitomi Kenichiro , Une Atsunobu , Mochida Masaaki
Published: September 2009

The size of the photo mask and mother glass used in liquid crystal display production has increased yearly. Large rectangular glass plates are difficult to planarize using rotary-type polishing machines. We have developed a rotary-type polishing machine with tool path control that is optimized by polishing simulation for a rectangular wafer. The present paper describes the planarization of a rectangular plate by simulation. The influence of tool size and the aspect ratio of the rectangular plate on the flatness are clarified. For a square plate, the flatness obtained under optimized oscillation speed is less than a quarter of that obtained under uniform oscillation speed. For rectangular plates with aspect ratios of 1:1.25 and 1:1.5, planarization using a tool having a diameter equal to half the diagonal length of the plate is shown to be difficult because the stock removal distributions in diagonal and short side of the workpiece become the different shape.
Electric Field-Assisted Glass Polishing Using Electro-Rheological Gel Pad
Authors: Kakinuma Yasuhiro , Takezawa Singo , Aoyama Tojiro , Tanaka Katsutoshi , Anzai Hidenobu
Published: September 2009

. A polishing process, which is the final process in manufacturing optical elements, takes a long time and often depends on the experience and special skills. Development of a skill-less polishing technology and automation of its process, therefore, has been required. One of the most promising polishing technologies is Field-assisted Fine Finishing (FFF). In this study, an Electro-rheological Gel (ERG) polishing pad with one-sided patterned electrodes is developed to polish insulator materials and, moreover, a novel electric-field-assisted polishing technology for glass polishing is proposed applying this pad. The ERG polishing pad can change the polishing performance according to applied electric field due to “electro-adhesion effect”. Results of several polishing tests show that the performance of polishing a blue glass can be controlled by applying electric field to the ERG pad.
The Study on the Abrasion Characteristic of Wafer Surface According to Machining Condition
Authors: Lee Eun Sang , Won Jong Koo , Lee Jung Taik , Choi Hon Jong
Published: September 2009

It is important to obtain the optimal condition in wafer polishing processing. Polishing is one of the most important methods in manufacturing of Si wafers and in thinning of completed device wafer. This study will report the evaluation on abrasion of wafer according to processing time; machining speed and pressure which have the major influence on the abrasion of Si wafer polishing, for this, this study design the head unit and analysis head unit. After that, this study applies to experiment. The evaluation of abrasion according to processing condition is selected to use result data that measure a pressure, machining speed, and the processing time. This result is appeared by machining condition. Through that, the study can evaluate the abrasion characteristic of wafer in machining.
A Note on the Unloading Behavior of Silicon Subjected to Nanoindentation
Authors: Chang Li , Zhang Liang Chi
Published: September 2009

It is known that silicon, during nanoindentation unloading, undergoes various phase transformations beneath the indenter. Investigations into the details are however not available. This paper studies the unloading behavior of silicon subjected to cyclic nanoindentations. The results show that the elastic unloading behavior of the material can be described by a power relationship, P = α∙hm, where P is the load, h is the elastic displacement, and α and m are material constants. It was found that the values of α and m were almost independent of the phase transition events, indicating that the elastic response of the material is mostly governed by the mechanical properties of Si-I phase while the influence of the phase transformations is negligible.
Deformation and Acoustic Emission during Nanoindentation on Single Crystal MgO (001) Plane
Authors: Dong Zhi Gang , Huang Han , Kang Ren Ke
Published: September 2009

Nanoindentation tests with the aid of acoustic emission monitoring were performed on single crystal MgO (001) plane to investigate the deformation of MgO under high indentation pressures. The results indicated that the deformation of MgO under nanoindentation with a sharp indenter could be classified into three stages: elastic deformation, elastoplastic deformation, and fragmentation. The elastic energy release and fracture occurred could be identified using acoustic emission signals.
Development of CBN Internal Grinding Machine for Precision Grinding of the Air-Conditioner Compressor Piston Hole
Authors: Zheng Y.G. , Liu W.G. , Jiang Bin , Gao Hang , Zheng S.G.
Published: September 2009

According to the demand for internal grinding machine in precise machining of air-conditioner compressor piston hole, a kind of high precise CNC internal grinding machine with CBN wheel is developed by adopting self-adaptive control for grinding process. Meanwhile, grinding precision and stability are achieved by overcoming many problems emerging from high-speed grinding process with CBN wheel. More than 100000 times’ grinding experimental results show that the whole performance of grinding machine developed is the same as that of the same kind of international machine. In order to study grinding mechanism with CBN wheels and then improve machine’s capability, grinding data in several machining cycles is analyzed.
Processing Grinding-Damaged Silicon Wafers by High-Frequency Nano-Second Laser Irradiation
Authors: Yan Ji Wang , Muto Sei Ya , Kuriyagawa Tsunemoto
Published: September 2009

Ultraprecision diamond-ground silicon wafers were irradiated by a high-frequency nanosecond pulsed Nd:YAG laser equipped on a four-axis numerically controlled stage. The resulting specimens were characterized using a white-light interferometer, a micro-Raman spectroscope and a transmission electron microscope. The results indicate that around the laser beam center where the laser energy density is sufficiently high, the grinding-induced amorphous silicon was completely transformed into the single-crystal structure. The optimum conditions for one- and two-dimensional overlapping irradiation were experimentally obtained for processing large-diameter silicon wafers. It was found that the energy density level required for completely removing the dislocations is higher than that for recrystallizing the amorphous silicon. After laser irradiation, the surface unevenness has been remarkably flattened.
Measuring Surface Uniformity in Chemical Mechanical Polishing
Authors: Baik Jae Won , Kang Chang Wook
Published: September 2009

Chemical mechanical polishing (CMP) is a technique used in semiconductor fabrication for planarizing the top surface of an in-process semiconductor wafer. Especially, Post-CMP thickness variations are known to have a severe impact on the stability of downstream processes and ultimately on device yield. Hence understanding how to quantify and characterize this non-uniformity is significant step towards statistical process control to achieve higher quality and enhanced productivity. The main reason is that the non-uniformed interface between the wafer and the machine-pad adversely affects the polishing performance and ultimate surface uniformity. The purpose of this paper is to suggest a new measure that estimates the uniformity of wafer surface considering the difference of the amount of abrasion between the center and the edge. This new measure which is called the Coefficient of Uniformity is defined as the following ratio: Geometric Mean (GM) / Arithmetic Mean (AM). This metric can be evaluated regionally to quantify the non-uniformity on the wafer surface from the center to the edge. Further simulations show that this new measure is insensitive to shift of the wafer center and sensitive to shift of the wafer edge. This trend indicates that this new measure is a very useful to test the non-uniformity of wafer after CMP polishing.
The Effect of Cooling Lubrication Methods on Surface Roughness Measured by the White Light Interferometer
Authors: Jiang Feng , Li Jian Feng , Sun Jie , Zhang Song
Published: September 2009

Surface roughness is an important item to evaluate the surface quality. Many researches focused on the optimization of cutting parameters in the specified cooling/lubrication conditions. But the effect of different cooling/lubrication conditions was still less considered. Aimed at this problem, the effect of cutting parameters on the average surface roughness (Ra) in the different cooling/lubrication conditions, including MQL, wet, dry cutting, was analyzed in this study. Orthogonal arrays were applied in the design of the experiments and Ti6Al4V end-milling experiments were performed on the DAEWOO machining center. The white light interferometer was used to obtain the 3D profile of machined surface and calculate the Ra values. The regression analysis and statistical analysis of variance were employed in the process of the experimental data. The relationships between Ra and cutting parameters in the different cooling/lubrication conditions were obtained and the optimum values of the cutting parameters in the range of the experiments were selected.
Fundamentals of BK7 Glass Removal in Micro/Nano-Machining
Authors: Chen Ming , An Qing Long , Lin Wei Min , Ohmori Hitoshi
Published: September 2009

The confine of ductile-mode cutting and brittle-mode cutting seems to be a crucial step for designing a brittle material removal process. However, the existing transition from ductile-mode to brittle-mode for BK7 material makes the confine of different mode very difficult. Through a series of micro/nano-machining tests, measurements of cutting forces and morphological appearance of cutting groove as well as the cross section at the certain depth of cut, the confirmation of ductile-mode cutting, transition-mode cutting and brittle-mode cutting has been clearly described in the paper. This lays a foundation for the fundamental understanding of cutting physics concerning of material characteristics and cutting tools, and thereafter for the development of optimal process technology.
Surface Characteristics and Roughness Prediction of TC4 Titanium Alloy in High Speed Grinding
Authors: Yin Shao Hui , Tang Kun , Sheng Xiao Min , Zhu Yong Jian , Fan Y.F.
Published: September 2009

This paper reports a systematic investigation of high speed grinding of hard-to-machining of titanium alloys. The ground surfaces were characterized using scanning electron microscopy, and the effects of different grinding parameters on roughness were discussed. A numerical model was established to predict surface roughness based on the evolutionary neural network optimized by Genetic Algorithm (GA). The modeled results were in good agreement with the experimental results.
The Experimental Research on Small Hole Machining in Glass Using Diamond Abrasive Core-Tools
Authors: Quan Yan Ming , Liang Liang , Zhong Wen Wang
Published: September 2009

Glass is a kind of difficult-to-machine material due to its hard and brittle properties. Although many special hole machining methods for brittle and hard materials have been developed, the traditional drilling is still widely applied because it is simple and reliable. However, the drilling tool for hard and brittle material is an obstacle, especially for small hole drilling. In this paper, two types of diamond abrasive core-tools which are made by electroplating and sintering process are used to machine small holes in glass plates, their structures are introduced and their machining performances are compared. The experimental result indicates that these diamond abrasive tools are satisfied for small hole machining in glass, and the performance of electroplating tool is better than that of sintering one.
Fabrication of Carbon Nanotube Probes in Atomic Force Microscopy
Authors: Xu Zong Wei , Fang Feng Zhou , Hu Xiao Tang
Published: September 2009

Carbon nanotube (CNT) probe used in atomic force microscopy (AFM) was fabricated by using electron beam induced Pt deposition method. The bonding force for CNT probe was found to be larger than 500nN. The nanotube probe’s length was shortened by focused ion beam milling process. It is confirmed that the CNT probe shows higher aspect ratio than the Si probe. The nanotube probes with fullerene-like cap end present higher imaging resolution than those with open end.
A Study of Carbon Nanotubes as Cutting Grains for Nano Machining
Authors: You J. , Gao Y.
Published: September 2009

We propose to use nano structures directly to fully utilize the nice mechanical and thermal properties for nano machining. In this project, CNTs were directly used as cutting grains. For the CNT grains, we use epoxy as one of the bonding materials of our choice. A series of CNT grinding wheels were fabricated to demonstrate the effectiveness of the proposed new type of abrasive tool. Preliminary experimental tests were conducted for the proposed method of abrasive tool making. The CNT wheels are made of 1% MWCNTs or Multi Wall CNTs. Preliminary test results show that CNT wheels without functionalization or chemical treatment give the best average results. In the developed abrasive tool, CNT nano cutting edges are clearly seen in the TEM image. Carbon nanotubes can be used as cutting grains for nano machining. Further experiments are necessary.
Study on Unique Cutting Phenomena in Micro Endmilling - Mechanism and Possibility to Occur-
Authors: Nomura Mitsuyoshi , Kawashima Takahiro , Shibata Takayuki , Murakami Yoshihiko , Masuda Masami , Horiuchi Osamu
Published: September 2009

In micro endmilling, because of small uncut chip thickness comparable to the tool edge radius and low rigidity of tool, the cutting process must frequently transit between rubbing/ploughing and cutting, and it may deteriorate the machining stability, surface finish and tool wear. In this report, such unique cutting phenomena are investigated by modeling a mechanism, computer simulations and experiments. As a result, a possibility of the unique cutting phenomena proposed has been certified.
Study on Replication of Micro Channel Structures onto Polytetrafluoroethylene (PTFE) Substrate Employing Two-Stage Hot Embossing
Authors: Hira Shin-Ichiro , Yoshioka Masato , Wang Zhu Qing , Zhang Yu , Nobukawa Yutaka
Published: September 2009

Replication of micro structures on a polymer substrate employing two-stage hot embossing is described in this paper. Linear channels with rectangular cross section were fabricated on a master mold of a brass plate by means of a computer numerical control (CNC) machining center using a micro end mill. In the first embossing process, the master mold with concavity features was embossed on a polycarbonate (PC) plate in order to make a “polymer replication mold”. Polytetrafluoroethylene (PTFE) was chosen as a material of polymer substrate used in the second embossing process. The replicated structure on PTFE substrate was observed and each dimension of its cross-sectional shape was also measured in order to assess the replication accuracy. According to the results, it was found that the depth of a replicated channel was near 90 % of that on the master mold. But roundness at each corner could be also found due to the insufficiency of plastic flow. Furthermore the deformation of the structures on a replication mold of PC before and after 2nd hot embossing process was also examined. As a result, it was found that the deformation ratio at temperatures below 145 oC was roughly smaller than 10 %.
Surface Profile Simulation during Plane Strain Compression by Crystal Plasticity Finite Element Method
Authors: Li Hei Jie , Jiang Zheng Yi , Wei Dong Bin , Du Yan Bing , Han Jing Tao , Tieu A. Kiet
Published: September 2009

With the technology advancement, crystal plasticity finite element modeling becomes more and more popular in the simulation of metal forming process. In order to obtain a better understanding of the difference between the Taylor model and finite element model during the simulation of metal forming process, an implicit time-integration procedure with the two polycrystal models is applied in the commercial finite element code ABAQUS to simulate the plane strain compression separately. FCC metal is used in this study. The simulation shows that the two polycrystal models both can predict the compression process approximately. The two modelling results of surface roughness show an agreement with that of the experimental results. However, the side profile calculated by the Taylor polycrystal model is much steeper and straighter than that of finite element polycrystal model. The experimental surface roughness curve shows a high frequency fluctuation. It is much steeper than those of the two models. The simulation results also show that the von Mises stress from the Taylor model is much higher than that of the finite element model.
Modeling and Optimization of Process Parameters in Micro Wire EDM by Genetic Algorithm
Authors: Somashekhar K.P. , Ramachandran N. , Mathew Jose
Published: September 2009

The present work is aimed at optimizing the parameters of micro Wire Electric Discharge Machining (µ-WEDM) process by considering the simultaneous effects of input parameters viz: gap voltage, capacitance and feed rate. Experiments were planned and conducted using DoE techniques. ANOVA was performed to find out the significance of each factor. Regression models were developed for the experimental results of surface roughness and overcut of the micro slots produced on aluminium. Then Genetic Algorithm (GA) was employed to determine the values of optimal process parameters for the desired output value of micro wire electric discharge machining characteristics.
Fabrication of Multiple Micro-Grooves by Ultrasonic Machining with a Tool that Laminated Thin Hard-Material and Thin Soft-Material
Authors: Shinozuka Jun
Published: September 2009

A micro-grooving method by ultrasonic machining with a lamination tool has been devised. Thin walls on the tip of an ultrasonic tool can fabricate many grooves on a workpiece by one ultrasonic-machining process. Thinner wall for fabricating micro grooves, however, poses the lack of the stiffness of the tool, resulting in the difficulty of the grooving. Then the walls are enfolded with a soft material such as a polymer plastic to supplement the lack of the stiffness. Since soft material absorbs the energy of the ultrasonic vibration, the damage by the impacts of the abrasive particle on the workpiece surface under the soft material is little. Therefore multiple micro-grooves can fabricate efficiently by using of a lamination tool in which thin hard-materials and thin soft-materials are laminated alternately. In this paper, the lamination tools were developed with a thin shim-sheet as the hard material and an epoxy adhesive as the soft material. The fabrication experiments of the parallel grooves on alumina ceramics were conducted. This paper investigates the influences of the parameters of ultrasonic machining such as the grain size of the abrasive particle, the static machining load or static normal stress applied to the tool-workpiece contact region and the grooving time upon the characteristics of the micro-grooves. The results show that the grooving efficiency depends on the grooving time and the static normal stress. Finally, some applications are shown.
Towards Improving Rock Cutting Tools Using Thermally Stable Diamond Composites
Authors: Alehossein Habib , Li Xing S. , Boland Jim N.
Published: September 2009

Industrial application of synthetic diamond ceramics is growing very fast due to their super hardness, superb wear resistance and long-life durability. In rock, concrete and metal cutting, drilling, mining and quarrying and dimension stone industries, cutting tools made of diamond composites or impregnated diamond composite segments are gradually replacing the more commonly used cemented tungsten carbide (WC) tools. Through its SMARTCUT research program, CSIRO in the past 15 years has developed harder and stronger thermally stable diamond composite (TSDC) drag picks to encourage and help manufacturing and mining industries improve their cutting performance by replacing these traditional WC cutting tools with the new revolutionary TSDC tools. This improvement process however is much more complex than a simple material or cutting tool replacement, since the mechanism and configuration of cutting are substantially different in the two cutter head systems and its successful implementation requires a better understanding of the basics of rock cutting. Some of the factors influencing the differences are: cutter wear, fracture toughness, compressive and tensile strength, thermal properties, geometrical shape, spacing, angle of attack, rake angle, sharpness and bluntness characteristics, lacing design and cutter arrangements. Besides, it is most important to understand the relation between the tool or tool force and the fragmentation of the rock, which is the main focus of this paper.
A Study of the Grinding Alumina for the Multi-Point Diamond Tools
Authors: Luo Shenq Yih , Shih Ching Win , Chen M.H.
Published: September 2009

The purpose of this paper is to investigate the performance of grinding alumina for the specific designed tools containing a controlled diamond protrusion and arrangement. The grinding forces, workpiece roughness and diamond wear at changing the depth of cut and feed under a fixed spindle speed were studied in the experiments. The experiment results showed that the grinding forces with the increase of feed slowly increased. However, the grinding forces with the increase of depth of cut showed a relatively larger rise. When the depth of cut reached to 0.09 mm that is about one fourth of diamond size, the axial grinding force obtained above about 20 N to cause some weaker or higher protrusive diamonds to produce a relatively larger fracture or pull-out. Furthermore, under a larger depth of cut and a larger feed rate the workpiece roughness obtained was the poorer. When diamond tool was employed for a longer time test under the depth of cut less than about one fourth of grit diameter, diamonds mainly displayed an attritious wear and the alumina roughness was about Ra 1.2-2.2 μm. This designed diamond tools are feasible for grinding alumina.
Effect of Microstructure on Mechanical Properties and Wear Characteristics of Cemented Tungsten Carbides
Authors: Sun H.Q. , Irwan Rudy , Huang Han , Stachowiak Gwidon W.
Published: September 2009

The effect of microstructure of cemented tungsten carbide materials on their mechanical properties and wear characteristics was investigated using nanoindentation and nanoscratch methods. The results indicated that the variation in grain size insignificantly affected the hardness, elastic modulus and friction coefficient of the work materials, but considerably influenced their removal rates. The carbide with coarser grains exhibited a much higher removal rate was obtained during scratching.
Surface Integrity in Electrical Discharge Machining of Ti-6Al-4V
Authors: Yu Jian Wu , Xiao Peng , Liao Yu Shan , Cheng Min
Published: September 2009

Titanium alloy is a kind of typical difficult-to-machine materials. In this study, the surface integrity of titanium alloy Ti-6Al-4V machined by electrical discharge machining (EDM) method are experimentally investigated and analyzed in term of surface roughness, SEM micrographs and microcracks. Effect of discharge energy and material properties on surface integrity are presented in this paper.
Effect of Helical Drill Points on Delamination in Drilling Carbon Fiber Reinforced Plastics (CFRP)
Authors: Zou Ping , Yang Xu Lei , Li Xi You
Published: September 2009

A study of helical drill points for drilling carbon fiber reinforced plastics (CFRP) is presented. A helical drill point has an “S” contour with a radiused crown chisel that reduces the thrust force and make the drills self-centering. The S-shape chisel edge has a lower negative rake angle than a conventional chisel edge, and therefore may cut rather than extrude material. Experiments of drilling CFRP with helical drill points and conventional drill points were conducted. The results indicate that the helical drill points can reduce delamination significantly as compared to the conventional drill points under same cutting condition. Otherwise, delamination size decreases with increasing the cutting speed and increases with increasing the feed
A Preliminary Study of Variable Strength Activation of Coolant for Precision Machining
Authors: Gao Y. , Zhou S. , Zhang Y.
Published: September 2009

A new active cooling method is proposed for increased cooling effectiveness of coolant in grinding. It is based on variable strength activation of coolant together with active cooling to allow better machining heat transfer through mist evaporation. Multiple actuators are used through superposition and focusing. A device of variable strength coolant activation has been developed. Preliminary experimental tests were conducted to test the feasibility of the proposed cooling method. It is found that, using the proposed variable strength activation, an improvement of 87.6% in Ra value and 71.9% in Rq value were obtained when compared with the existing activated and cooled coolant cooling method.
Electrode Design for Oscillating EDM
Authors: Nakamura Yuki , Sriani Tutik , Aoyama Hideki
Published: September 2009

In die-sinking EDM, the electrode is moved only in the Z-axis direction, while in oscillating EDM, electrodes are oscillated in both the X-axis and Y-axis directions to realize high accuracy machining. There are many ways of designing electrodes for oscillating EDM. However, because the form of electrodes and subsequently the oscillating patterns of these electrodes depend on the shapes of the die/mold used, they become complicated when the die/mold shape is complicated, and electrode design takes hours in such cases. This paper therefore proposes a new approach of designing electrodes for oscillating EDM. Some oscillating patterns based on the proposed approach are also analyzed from the viewpoint of usefulness.
Study on Precision Machine Table Equipped with Constant-Flow Hydrostatic Water Bearings
Authors: Yui Akinori , Okuyama Shigeki , Kitajima Takayuki , Fujita Etsuo , Slocum Alexander Henry , Rothenhofer Gerald
Published: September 2009

In order to realize environmental-friendly machine tools, a linear-motor-driven table supported by constant-flow hydrostatic water bearings is developed. The table system is free from environmental pollution because the system needs no oil. For simplicity, a single-sided bearing system is chosen for the table-slide. To obtain a high sustaining force, preload is applied to the bearings using the attractive force of an iron core linear-motor’s magnets. The preload is effective in both the vertical and horizontal directions by inclined motor magnets. Miniature gear-pumps supply flow to the bearings without pump pulsation, and the bearings consume very small amounts of water and electric power. The measured table sustaining force was 3.0kN and static stiffness was 0.3kN/m under a flow rate Q=0.92mL/s per bearing and ideal bearing clearance h=16m.
Developments of Industrial Diamond Industry in China
Authors: Li Zhi Hong , Jia Pan , Li Liang
Published: September 2009

The development of China as the world's manufacturing house is best exemplified in the industry of diamond superabrasives. Diamond is indispensable in the creation of industrial infrastructure, including the construction of roads and building of houses. The diamond market was previously dominated by countries outside China. However, a "great leap forward" has taken in China with rapid expansion in Chinese diamond-making capabilities from the enlargement of the equipment (cubic presses) and improvements in diamond yield and product quality in the end of last century. In the new millennium, China outpaced the rest world combined in the total diamond output, became the largest producer in the world indubitably. This paper presents the progress in recent years based on the statitics, and also an outlook of the future development of the Chinese superabrasives industry based on the Chinese macroeconomics and the recent data of the end-users as well as their future development trend.
High Temperature Interfacial Reaction between Glass Gobs and Sol-Gel Coated Al2O3 Films
Authors: Chien His Hsin , Ma Kung Jeng , Vattikuti S. Prabhakar , Kuo Chien Hung , Huo Zen Bong , Chao Choung Lii
Published: September 2009

. Glass molding process is considered to have a great potential for the mass production of optical components with lower cost. Up to now, the service life of molding dies is still not satisfied. This study mainly focuses on the development of sol-gel derived Al2O3 coatings in order to extend the service life of glass molding dies. High temperature glass wetting experiment was carried out to investigate the high temperature interfacial reaction between the coatings and glass gobs. The 304 stainless steel were used as the substrate materials. The sol-gel coated Al2O3 was selected as the protective coating. OHARA L-BAL42 glass gobs were chosen as the test materials. It can be observed that very severe interfacial reaction occurs between stainless steel and glass at high temperature. The contact angle dramatically decreases from initial and then gradually approaches 25° at 825°C after 2 minutes holding time. The severe interface chemical reaction also results in the loss of transparency in glass appearance. The reaction products such as Zn and Ba are mainly from glass material. For the case of Al2O3 coated substrate, the variation of the contact angles varied from 152 to 138°, presents anti-sticking or non wetting behavior. There are no reaction products can be found on the glass contacted area after wetting test.
Study on Mechanical Properties and Size Effect of Si3N4 Using Discrete Element Method
Authors: Tan Yuan Qiang , Jiang Sheng Qiang , Li Cai , Yang Dong Min , Zhang Gao Feng , Sheng Y.
Published: September 2009

The mechanical models formed by packed circular discrete elements were used to investigate the mechanical properties of Si3N4. In these models, the distribution of elements is random in the specified region, and the average radius of elements is 6m. The main mechanical properties investigated here are Young’s modulus, compressive strength, Poisson’s ratio, fracture toughness and bending strength. Some numerical simulation analysis of the size effect of the mechanical properties in these discrete element models were carried out. The simulation results suggest that there is no obvious size effect for Young’s modulus, compressive strength and Poisson’s ratio in these discrete element models. However, for bending strength, when the number of elements in model is less than about 9000, there exists obvious size effect, with the increasing of the number of the elements, the size effect will become less and less until disappeared. The value of fracture toughness decreases with the increasing of the number of the model elements. The classical continuum fracture mechanics model about material fracture under tensile stress is also established by discrete element method. The simulation results are just the same as the simulation results of single edge notched bending (SENB) and the experimental values reported in other literatures. The results provide a more reliable foundation for the application of DEM in simulating the mechanical behaviors of advance ceramics.
Research on Microscopic Grain-Workpiece Interaction in Grinding through Micro-Cutting Simulation, Part 1: Mechanism Study
Authors: Li Xue Kun , Yan Lan , Rashid Waleed Bin , Rong Yi Ming
Published: September 2009

Grinding is regarded as a special multiple edge cutting process, which can be decomposed into grain-workpiece interface, chip-workpiece/bond interface, and bond-workpiece interface at microscopic level. The grain-workpiece interface, which resembles a micro-cutting process, directly modifies the workpiece surface and dominates all the output measures of a grinding process. Therefore, the study of the grain-workpiece interaction through micro-cutting analysis becomes necessary. As the emergence of the packaged FEM software for micro-cutting simulation, apart from single grit cutting test, it enables another qualitative and quantitative investigation method on grain-workpiece interface mechanism in an efficiency and effective manner. In this paper, the efficacy of the commercialized cutting simulation software Third Wave AdvantEdgeTM is evaluated, and the possibility of using AdvantEdgeTM for in-depth understanding of grain-workpiece interface as well as grinding process modeling is studied, too.
Corrosion Behavior of Al-Si-Cr-Cu Bearing Low Carbon Steel in A Cyclic Dry/Wet Laboratory Test
Authors: Zhang Hui Shu , Zhan Dong Ping , Bai Song Lian , Jiang Zhou Hua
Published: September 2009

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.
Synthesis and Characterization of Polyorganosiloxane Modified Waterborne Polyurethane
Authors: Luo Sui Lian , Liu Chao Dong , Gong Guo Fei , Lai Hei Ping , Kong Wen Zhong
Published: September 2009

In this work, PDMS modified PU was synthesized using two-stage method to improve water resistance and weather resistance in the waterborne polyurethane was investigated. It was found that the absorbed water content decreased with increasing PDMS content in polyurethane. It was also found that PDMS modified polyurethane had better solvent resistance than unmodified polyurethane. The structure incorporated the PDMS into the soft segment of polyurethane chains was confirmed by FTIR. The phase separation increased by increasing PDMS content and was confirmed by DSC. The particle size of the dispersions increased and tensile strength and hardness decreased with the increase of PDMS content. Furthermore, with the improved water resistance and elongation, it was hoped that the modified polyurethane could be used as wood coatings superior to the solvent-borne systems.
Synthesis and Gas Sensing Properties of Urchin-Like CuO Self-Assembled by Nanorods through a Poly(ethylene glycol)-Assisted Hydrothermal Process
Authors: Li Jiang Ying , Xi Bao Juan , Pan Jun , Qian Yi Tai
Published: September 2009

Urchin-like CuO, consisting of closely packed nanorods with a diameter of 10nm, have been successfully synthesized by a poly(ethylene glycol) (PEG)-assisted hydrothermal route at low temperature of 100°C. The as-obtained Urchin-like CuO were thoroughly characterized by X-ray diffraction (XRD) study, Field emission scanning electron microscope (FESEM), High-resolution transmission electron microscopy (HRTEM) and Gas sensor measurements. From the XRD pattern, all the peaks detected can be assigned to CuO in a monoclinic structure with lattice parameters a=4.662, b=3.416 and c=5.118 (JCPDS card no. 65-2309). The FESEM and TEM showed that the diameter of the urchin-like CuO sphere is about 1µm. Further investigation of the formation mechanism reveals that the PEG-assisted hydrothermal process is vital to the formation of 3D structures. Besides the template function, PEG often plays as a reductant while reacting with Cu(+2). In our case, no impurity peaks of Cu2O were observed in the XRD pattern, implying that PEG did not reduce Cu(+2) to Cu(+1). We attribute this to the high concentration of PEG. The sensor based on the urchin-like CuO nanostructures exhibit excellent ethanol-sensing properties at reduced working temperature (200°C), which shows a sensitivity two times higher than that of CuO particles(about 100nm, made from calcinations of Cu(NO3)2 at 400°C). The enhancement in sensitivity of the as-prepared CuO may be contributed to the fancy 3D nanostructures.
Water-Based Polyaniline/Montmorillonite/Epoxy Composite Coatings for the Corrosion Protection of Mild Steel
Authors: Li Yu Feng , Gao Xiao Hui , Zhu Hong Lei , Yang Liu
Published: September 2009

Polystyrene sulfonic acid (PSSA) doped water-dispersible polyaniline (PANI) /montmorillonite (MMT) clay composites were firstly synthesized by intercalation polymerisation in aqueous medium and characterized by XRD and FT-IR. The results showed exfoliated silicate nanolayers of MMT clay dispersed in the PANI matrix and has interaction involving hydrogen bonding between the PSSA-PANI chain and the surface of the MMT clay layer. This composites is more thermal stable than that of without clay samples and results in good stable temperature-dependent dc conductivity [σdc(T)] as temperature changed. The composite anticorrosion coatings of PANI/MMT and waterborne epoxy resin emulsion (EP) were prepared by mixture in aqueous medium and used for corrosion protection of mild steel. Open circuit potential (OCP), Electrochemical impedance spectroscopy (EIS) and Tafel plot demonstrated that the PANI/MMT/EP composite coatings have better anticorrosion properties than PANI/EP, MMT/EP and PANI/MMT/EP mixture. It’s impedance and corrosion potential is higher and the corrosion current density is lower. The anticorrosion coatings are environmental friendly because of water dispersion medium.
Introduction
Morphology Characterization and Optical Properties Analysis for Nanostructured Lanthanum Hexaboride Powders
Authors: Zhang Lin , He Wen Jun , Tolochko Oleg V. , Polzik Leonid , Min Guang Hui
Published: September 2009

Nanostructured Lanthanum hexaboride (LaB6) powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectra (XPS). The average size of LaB6 nanoparticles is about 35nm, which are well crystallized with ball or ellipsoid with inconspicuous corners and covered by a 3-5nm thick amorphous layer containing oxygen and carbon. The absorption of LaB6 nanoparticles in visible and near infrared spectrum (NIR) was measured and compared with micron scale particles. The surface plasmon responance (SPR) of nanoparticles was very efficient at NIR blocking, which almost covered the whole NIR region. The influence of nanoparticles concentration on spectrum absorption was comparatively evident. Meanwhile, micron particles almost haven’t NIR blocking function.
Analytical Characterization and Corrosion Behavior of Non-Functional Bis-Silane Pre-Treated Carbon Steel Substrates
Authors: Zhu Hai Ying , Chen Yan , Liu Yun Ping , Sun Wei Wei , Chen Shou Gang
Published: September 2009

The present work aims at studying the corrosion resistance of carbon steel substrates pre-treated with bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) solutions. The corrosion behavior of the pre-treated substrates during immersion in seawater was assessed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The analytical characterization of the silane films was performed by scanning electron microscopy (SEM). The results show that the pre-treatments based on silanes provide good corrosion protection of carbon steel substrates and the bis-silane film has good adhesion properties.
Electrochemical Corrosion Behavior of Cu-15Ni-8Sn Alloy in Marine Microbial Medium
Authors: Lei Yan Hua , Yin Yan Sheng , Liu Chao Hong , Chang Xue Ting , Chen Yan , Cheng Sha
Published: September 2009

A comparative study of the corrosion behavior of the copper-nickel-tin alloy in a nutrient–rich simulated seawater-based nutrient-rich medium in the presence and the absence of the marine bacteria was carried out by electrochemical experiments, microscopic methods. Comparing to the corresponding control samples, the electrochemical data demonstrated that the presence of the bacteria accelerated the corrosion of the alloy. Scanning electron microscopy (SEM) images revealed the occurrence of micro-pitting and intergranular corrosion underneath the biofilm on the alloy surface.
Numerical Study on Rapid Solidification of a Plasma-Sprayed Cast Iron Splat on a High-Temperature Substrate
Authors: Xing Ya Zhe , Wei Qiu Lan , Hao Jian Min , Shang Can
Published: September 2009

In this work, an experiment was performed to demonstrate the possibility of the metallurgical bonding in plasma-sprayed cast iron coatings at high substrate temperature. A quantitative analysis of splat cooling and rapid solidification of cast iron splat is then presented. The effect of the substrate temperature on the development of melt undercooling within the splat is investigated in detail. The results indicated that the initial substrate temperature has a profound effect on the development of melt undercooling in a splat, the splat bottom melt temperature, and the substrate surface temperature. A high initial temperature of the substrate restrains the cooling of the splat and leads to a high melt temperature that may promote the grain growth directly on cast iron substrate surface to form the metallurgical bonding.
Research on Chaotic Behavior of Concrete under External Load Based on Discontinuous Medium Mechanical Model
Authors: Qin Hao , Li Shu Cai
Published: September 2009

Outburst and random are typical characters of concrete when under external load. Traditional mechanics methods are difficult to be applied in. Depend on nonlinear science to set up the nonlinear dynamical equation that is fit for its characteristics. The subsystem dynamical equation of concrete is set up based on discontinuous medium mechanical model, and find that the concrete dynamical equation under external load is a Duffin equation. Then analyze and discuss the effect of external load on concrete by math analysis soft of maple. Results show that the concrete material take on complicated response to external load change.