bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Laser Shock Peening on Fatigue Life in Ni-Based Superalloy
Authors: He Wei Feng , Li Ying Hong , Li Qi Peng , Liu Hai Lei , Li Yu Qin , Liu Rui Jun
Published: October 2010

The goal of this work was to determine effects of laser shock peening (LSP) on the fatigue life of the nickel-based superalloy, as well as the mechanism including the residual stress-depth profile (both depth of compression and magnitude) and the microstructure. The vibration fatigue performance of the standard test coupons made by Ni-based superalloy K417 with and without laser shock peening is researched. The residual stress distribution and microscopic structure after LSP are tested and analyzed by X-ray diffraction, SEM and TEM. The results indicated that the compress residual stress is up to 1.0mm in the test coupons after LSP, and the maximum residual compressive stress is about 660MPa under the surface. At the same time, the high pressure shock wave caused by laser propagate into the material which formed high density dislocation in the surface of the samples, and the γ' is divided leading to increase the sub-grain. Because of the deep residual compressive stress, high density dislocation and much more sub-grains, the vibration fatigue strength is improved about 180MPa by LSP. It is very instructive in the structure design and applying LSP to Ni-based superalloy.
Study on the Process of Pure Shearing and Fracture for AISI-1020 and AISI-1045 Blanking with Negative Clearance
Authors: Fan Wei Fu , Li Jian Hua , Zhang Zhong Mei
Published: October 2010

This paper carried through fine-blanking with negative clearance processing experiment with the AISI-1020 and AISI-1045 and obtained the work piece of fine blanking with negative clearance. The fractography photographs in the different deform regions of rollover zone, shearing band, fracture zone and under sheared surface were scanned by scanning electron microscope (SEM-JSM-6360LV). The research result indicates that the plastic flow of fine-blanking with negative clearance has been carried out to punch downspin, then jib at the place of allowance value, so that the length of work piece burnish band as much as possible to maximize and the length of the smooth shearing fracture could reach more than 90% thickness of the metallic sheet. Owing to the ejector negative direction blanking, the second burnish band could be formed in the process of ejecting and the work piece has no burr in the undermost sheared face. The place of fracture of fine-blanking with negative clearance has emerged into the middle of work piece, not into the sheared undermost. And the width of fracture band is very tiny, only 50-100 micron. The research result provides theoretic reference and the experimental data for the practice application. It has instructive significance and reference value to manufacturing application.
Experimental and FEM Study on Surface Quality in High Grade Petroleum Pipe Turning
Authors: Zheng X.H. , An Qing Long , Chen Ming , Liu Gang , Zhang Yun Shan
Published: October 2010

The petroleum pipes are key component of petroleum drilling instrument. Residual stress distribution and work hardening in oil pipe turning are discussed through cutting experiment. The experiment result shows that the depth of residual stress affecting layer is small but residual stress is big while work hardening is severe. The prediction of residual stress, cutting force and temperature are achieved through FEM method. The simulation results are constant with experiment results.
An Investigation on PRMMC Polishing with Electrochemical Mechanical Machining Process
Authors: Liu G.Y. , Guo Z.N. , Li Yuan Bo , Huang Z.G.
Published: October 2010

Since Particle Reinforced Metal Matrix Composites (PRMMC) normally applied Al2O3, SiC particle and other hard material as reinforce item, traditional manufacturing processes are hard to machine PRMMC with high efficiency and low tool cost. This paper presents an electrochemical mechanical (ECMM) hybrid polishing procedure for PRMMC, and the influences of parameters such as work voltage, grinding area proportion, the formula and concentration of electrolyte has been investigated. Through a hybrid polishing compound with a no Z direction feed pure mechanical grinding progress in Vx opposite direction, Ra around 0.5um PRMMC surface can be achieved.
Surface Roughness and Cutting Force of Inconel 718 Machined by Different Cutting Tools
Authors: Geng G.S. , Xu Jiu Hua , Fu Y.C. , Y B.
Published: October 2010

Given the stringent operating conditions to which super alloys are subjected to in aerospace, nuclear power and gas turbine industries, their efficient machining and generation of machined surfaces with high integrity assumes a lot of importance. Therefore, this paper presents an experimental investigation on the surface roughness and cutting force of Inconel 718 machined with several different kinds of cutting tools. Both single-factor and orthogonal experiments were carried out with cemented carbide, cermet and CBN tools. The effects of cutting tools and cutting parameters on the surface roughness and cutting force are investigated and the optimal cutting conditions are recommended.
Simulation and Experiment on the Residual Stress in Super-High Speed Grinding
Authors: Liu Yue Ming , Gong Ya Dong , Ding Wei , Han Ting Chao
Published: October 2010

In this paper, effective finite element model have been developed to simulation the plastic deformation cutting in the process for a single particle via the software of ABAQUS, observing the residual stress distribution in the machined surface, the experiment of grinding cylindrical workpiece has been brought in the test of super-high speed grinding, researching the residual stress under the machined surface by the method of X-ray diffraction, which can explore the different stresses from different super-high speed in actual, and help to analyze the means of reducing the residual stresses in theory.
Effect of Abrasive on the Machining Performance the EMR-Effect-Based Tiny-Grinding Wheel
Authors: Lu Jia Bin , Yan Qiu Sheng , Tian Hong , Gao Wei Qiang
Published: October 2010

Based on the electro-magneto-rheological (EMR) effect, the Fe3O4-based EMR fluid dispersed with micron-sized finishing abrasives is used as a polishing fluid to form a dynamical tiny-grinding wheel under an electro-magnetically coupled field. Using this EMR-effect-based tiny-grinding wheel, experiments were conducted to investigate the effect of the grain size, content and material of abrasive on material removal effect of normal glass. Results indicate that the abrasive can change the chain-like structure of the EMR-effect-based tiny-grinding wheel and influence the material removal ability of the tiny-grinding wheel remarkably. The material removal amount increases with the increase of the content of diamond abrasive in the EMR fluid, and grows slowly when the proportion of diamond abrasive exceeds to 6%. While the grain size of abrasive increases, the material removal amount increases at the beginning and decreases afterwards. The effect of abrasive on material removal depends on the hardness of abrasive, the greater the abrasive hardness, the higher the material removal efficiency. The machined area has a close relationship with both the density and grain size of abrasive.
Investigation of Surface Roughness during Turning Process Based on Response Surface Methodology
Authors: Han Shu , An Qing Long , Chen Ming , Liu Gang , Zhang Yun Shan
Published: October 2010

The purpose of this study was to analyze the effects of cutting parameters on the surface roughness (Ra) when turning of alloy cast iron using uncoated carbide insert under dry cutting condition. The mathematical model for the surface roughness was developed by response surface methodology (RSM).Response surface contours were constructed and used for determining the optimum cutting conditions to reduce machining time without increasing the surface roughness.
Optimization of Magneto Rheological Damper Based on the First Order Optimization
Authors: Ma Ping , Tang Yong Bo , Gong Zheng
Published: October 2010

For the design and development of the magneto-rheological (MR) damper in flexible fixture, a mathematical model to describe optimization problem and an optimization procedure are constructed through finite element method. A magnetic structural coupling analysis and a first-order optimization are combined to optimize the structural parameters of MR damper and the damping force of the optimized MR damper is tested on the experimental setup. The results show that the optimized MR damper has a reasonable magnetic flux density distribution and a controllable damping force to meet the requirement of the flexible fixture. The effectiveness and feasibility of the proposed optimization approach are verified.
Study on Super-Precision Grinding Processing to the Spindle with CBN Slipstone
Authors: Cui Jiang Hong , Shi Jian Ru , Chen Jian Fei
Published: October 2010

The spindle is an important part of twistering and winding in spinning frame. The spindle blade is the key element of spindle. As the development of hi-speed spindles, grinding accuracy and surface quality are greatly requested for the bearing class surface of the spindle. In the paper, an idea is presented to adopt super-precision grinding to machine the spindle blade. Throughing analyzing and discussing the super-precision grinding principle, A super-precision grinder was designed. A comparative test is made to investigate the differences between advanced CBN slipstone and ordinary abrasive corundum in performance. As a result, the surface roughness of the spindle blade which has been manufactured on the new grinder has reduced to Ra 0.01μm. The productivity of the new machine increases by 15 times.
Experimental Study on Ultrasonic Vibration Dressing Wheel
Authors: Xiang Dao Hui , Zhi Xin Tao , Yue Guang Xi , Zhao Bo , Fan Q.T.
Published: October 2010

Excellent wheel dressing technology can ensure the ground surface quality effectively. Because precision machining has a strict requirement on the wheel dressing, the wheel dressing with ultrasonic vibration was adopted, and the device of ultrasonic vibration dressing was also designed in this paper. On the base of analysis mechanism of ultrasonic vibration dressing wheel, the grinding experiment was carried out in different dressing conditions. The surface characteristics of ultrasonic dressing wheel and the influence of different dressing parameters on the workpiece surface quality were studied. Furthermore, the optimal dressing parameters have been obtained. The experiment results indicate that the micro cutting edge of grinding wheel distribute sparsely in circumferential directional but densely in axial direction in the condition of ultrasonic dressing, and it is particular characteristic of ultrasonic dressing. When the dressing and grinding conditions are suitable, the workpiece surface roughness can be reduced, but the conditions are not arbitrary. At the same time, the workpiece surface burn can be effectively reduced, even if the larger grinding depth is used during the grinding process.
Experimental Study on Turning of Alloy Cast Iron with Coated and Uncoated Tools
Authors: Wang Q.C. , An Qing Long , Chen Ming , Liu Gang , Zhang Yun Shan
Published: October 2010

Alloy cast iron cylinder is the mainstream product used in engine nowadays. However, the machinability of alloy cast iron is poor because of its enhanced mechanical properties. In this paper, turning experiment has been conducted to study machinability of alloy cast iron with uncoated and coated carbide tools under dry cutting condition. The results of the experiment indicated that the turning performance of alloy cast iron with coated tool was much better than uncoated tool in terms of cutting force coefficients and tool wear. Feed rate has a great influence on surface roughness, and appropriate tool wear is benefit of finished surface roughness.
Interface Temperature Measurement and Experimental Studies of Super-High Speed Polishing of CVD Diamond Films
Authors: Huang Shu Tao , Zhou Li , Xu Li Fu
Published: October 2010

Super-high speed polishing of diamond film is a newly proposed method due to its outstanding features such as low cost and simple apparatus. The interface temperature rise is due to the friction force and the relative sliding velocity between the CVD diamond film and the polishing metal plate surface. In this paper, the interface temperature rise in super-high speed polishing of CVD diamond film was investigated by using the single-point temperature measurement method. Additionally, the influence of polishing plate material on the characteristics of super-high speed polishing has been studied. The results showed that cast iron is not suitable for super-high polishing, while both 0Cr18Ni9 stainless steel and pure titanium can be used for the super-high polishing of CVD diamond film. The quality and efficiency of polishing with 0Cr18Ni9 stainless steel plate is much higher than those of pure titanium, and the material removal rate could reach to 36-51 m/h when the polishing speed and pressure are 100 m/s and 0.17-0.31 MPa, respectively.
Study of Surface of Edge Grinding of Ceramic Tile by Diamond Cup Wheels
Authors: Cheng Yun Ping , Wang Cheng Yong , Hu Ying Ning , Si Wei Zheng
Published: October 2010

As one of the excellent decorative materials, ceramic tiles must be ground and polished to present the glossy surface. Diamond cup wheel is one of important tools. Ceramic tiles were ground by diamond cup wheel with a special designed test machine. The materials’ removal process of ceramic tiles had been tested, and surface roughness was measured. The surface micromorphology of the polished ceramic tiles under different depth of grinding and feed speed was examined by Scanning Electron Microscopy (SEM). The results showed that a lot of materials’ removal can be obtained by increasing the depth of grinding and feed speed in rough process of ceramic tile. On the contrary, good surface can be obtained by reducing depth of grinding and feed speed in fine process of ceramic tile.
Surface Generation and Chip Formation when Ultra-Precision Turning of SiCp/Al Composites
Authors: Ge Ying Fei , Xu Jiu Hua , Fu Yu Can
Published: October 2010

Chip formation and surface generation were investigated when ultra-precision turning of SiCp/2009Al and SiCp/ZL101A composites using Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD) tools. The results showed that the machined surfaces took on many defects of pits, voids, microcracks, grooves, protuberance, matrix tearing etc. It was noticed that most of these defects had an intimate relationship with the removal process of SiC particle. The surface finish was much better when the SiC particles were removed by cut through or in-situ pressed into mechanisms. Material swelling and side flow, tool-workpiece relative vibration, feed rate and tool nose radius, removal mode of SiC particles were these main mechanisms of surface generation. Generally, a saw-toothed chip was formed when ultra-precision turning this kind of material and the mechanisms of this type of chip were dynamic microcrack behavior and strain concentration, which induced by the non-uniform deformation of the workpiece material.
Design and Implementation of the Cutting Dynamometer System Based on Virtual Instrument Technology
Authors: Zheng Zhi Dan , Zhang Zi Qiang , Chen Shao Bo
Published: October 2010

On Labview’s development platform, taking full advantage of multithreading management and data stream control, a quick-responding dynamometer system for cutting process is designed and developed based on the Usb interface. The system possesses functions such as data acquisition, signal generation, signal pre-processing, data storage and data analysis, has facile operation interface, and supports data post-processing and analysis well.
Process Parameter Optimization and Experimental Study of Micro-Holes in Electrochemical Micromachining Using Pulse Current
Authors: Li Zhi Yong , Niu Zong Wei
Published: October 2010

Electrochemical micro-machining (EMM) has become one of the main machining methods for production of miniaturized parts and components. Utilizing a developed EMM set-up, sets of experiments have been carried out to investigate the influences of some of the predominant electrochemical process parameters such as pulse frequency, feed rate of tool, machining voltage and ultrasonic frequency on the machining accuracy of micro-holes. According to the present investigation, the most effective zone of pulse on time and ultrasonic frequency can be considered as 15-50μs and 26KHZ, respectively, which can gives a desirable machining accuracy for micro-holes. A machining voltage range of 6-10V can be commended to obtain high machining accuracy. From the micrographs of the machined micro-holes, it may be observed that a lower value of electrolyte concentration with moderate machining voltage and moderate value of pulse on time will produce more accurate shape of micro-holes.
An Approximate Solution of Energy Partition in Grind-Hardening Process
Authors: Zhang Lei , Bi Wen Bo , Zhang Ru Bo
Published: October 2010

In order to estimate the energy partition within the workpiece, an integral approximation solution of energy partition is found in the grind-hardening process. Heat transfer models of the abrasive grain, workpiece, chips and fluid were analyzed by using the integral approximation method. The present model can calculate the energy partition with and without film boiling in the grinding zone. The temperature underneath the surface of the workpiece was measured using semi--natural thermocouple method. The workpiece background temperature calculated by the present model agreed very well with the experimental results. Energy partition model can be used to calculate the grinding temperature for controlling thermal damage and predicting the harden layer depth in grinding.
Study on the Effect of Nonionic Surfactant in Copper CMP Slurry
Authors: Huo Feng Wei , Jin Zhu Ji , Zhang Ran
Published: October 2010

The effect of surfactant in alkaline slurry for copper chemical mechanical polishing (CMP) was studied through polishing experiments with slurries containing different weight percentage of four nonionic surfactants respectively. The results indicate that properly chosen nonionic surfactants with proper weight percentage could result in little negative influence on the material removal rate, but can help to improve copper wafer surface quality significantly. Alkylphenol ethoxylates was found to be an excellent surfactant for alkaline slurry and a surface roughness of Ra 0.89nm and a material removal rate of 526 nm/min were obtained when polishing with the slurry containing 0.25 wt% alkylphenol ethoxylates, while the surface roughness and the material removal rate were Ra 1.34nm and 525 nm/min respectively when polishing with the origin slurry. The density of polishing defects such as scratches and etch pits decreased significantly. The action mechanism of surfactant was further analyzed based on the experiment results.
Experimental Study on the Characteristics of Surface Roughness in Ultrasonic Aided High-Speed Lapping of Engineering Ceramics
Authors: Jiao Feng , Zhao Bo , Liu Xiang
Published: October 2010

The surface roughness of machined surface is one of the important indicators to evaluate the workpiece machining quality. In order to clarify the change law of surface roughness in ultrasonic aided high-speed lapping with solid diamond abrasive, a series of ultrasonic and conventional lapping experiments of different engineering ceramics, such as Al2O3, ZrO2 and ZTA, were carried out on precision lathe with self-made high-speed ultrasonic lapping device. The research results show that the value of surface roughness in ultrasonic aided lapping is lower than that in conventional lapping. With the assistance of ultrasonic vibration, the surface quality can be improved obviously. In ultrasonic aided lapping, there is an optimum lapping pressure from which a better surface roughness value can be obtained. Because of different physical and mechanical properties, material removal mechanisms of the three kinds of engineering ceramics present different characteristics, which lead to the different surface roughness even though under the same lapping conditions. The research of the paper is helpful to optimize lapping technique and improve the surface quality.
Study on Axial Turning of Engineering Ceramics
Authors: Tian Xin Li , Guo Fang , Yang Jun Fei , Zhang Bao Guo , Mao Ya Tao
Published: October 2010

Axial turning is a method to cut the cylindrical work piece along its axis, using the kinetic energy of high-speed rotation annularity tool, the abrasives in tool tip (or toes) as the main cutting edge to remove materials and the abrasives in the inner surface of tool as a minor cutting edge to sharpen the processed surface. The cutting thickness and feed rate could be more than 3~5mm and 30mm/min respectively in a cutting, and realized high-efficient, low-cost processing of engineering ceramics. Processing mechanism analyses showed that both median/radial cracks and lateral cracks occurred in the part to be removed, and the intensity of the processed part had little destroyed, only needing adjust the axial force to control the length of transverse cracks.
Quantitative Evaluation of the Uniformity of Abrasive Distribution Based on Image Processing
Authors: Pan Bing Suo , Wan Biao , Fang Xiao Hong
Published: October 2010

In precision machining, the uniformity degree of abrasive distribution affects significantly the surface quality. To quantitatively evaluate the uniformity of abrasive distribution, in this paper digital image processing technology was employed to segment the working face images of impregnated diamond tools; mean crowding index was used to classify the pattern of abrasive distribution; fractal dimension determined by gyration radius method was applied to characterize the bulk uniformity of abrasive distribution on face plane; the coefficient of variation of Voronoi cell areas was adopted to describe the local distribution feature of abrasive grits. The results show that mean crowding index, fractal dimension and CV of Voronoi cell areas can characterize the uniformity of abrasive distribution from different points of view, and can be used to quantitatively evaluate the uniformity of abrasive distribution.
Simulation and Design of Experimental Equipment for Two-Phase Compulsive Circulation Flows Finishing
Authors: Yang Sheng Qiang , Li Wen Hui , Yang Shi Chun
Published: October 2010

For the precise hole surface, the burr severely affects products’ performance. Considering the specific conditions of the precise hole surface finishing, a new method of two-phase compulsive circulation flows finishing is brought up. On the basic premise of defining k-ε model, numerical simulation of finishing project is done and its feasibility is defined. Experimental equipment is designed, especially, component of circulation flows formation is analyzed in detail, which provide experimental basis for process parameters and thorough research.
A Deterministic Method to Predict Geometrical Interference between Grinding Wheel and Workpiece for Ultra-Precision Aspherical Grinding
Authors: Yin Shao Hui , Wang Ze Biao , Wang Yu , Chen Feng Jun , Yu Jian Wu
Published: October 2010

This paper reported a deterministic method to predict geometrical interferences between grinding wheel and workpiece on ultra-precision grinding for micro aspherical lens mould. An inclined axis grinding mode controlled by B axis is considered and investigated. For avoiding the interference between the grinding wheel and the workpiece, the relationship of the radius of the grinding wheel should be analyzed in the grinding process. In this paper, a geometrical mathematical model for avoiding interferences between grinding wheel and workpiece is built up, and three interference conditions are analyzed. The maximum diameter of the cylindrical grinding wheel is computed and obtained for grinding axisymmetric aspheric surface.
Experimental Study on Deburring, Form Error and Surface Roughness in Orbital Drilling of Hardened Steel
Authors: Chen Shi Fang , Xie Jin , Zhuo You Wang
Published: October 2010

An orbital drilling approach is proposed in machining hardened steel hole. In this study, the orbital drilling performance was investigated in connection with deburring, form error and surface roughness. First, the hole machinability of various steels was analyzed to compare an orbital drilling with a vertical drilling; then the orbital drilling experiments of hardened steel were carried out to investigate the effects of orbital drilling parameters such as tool speed, orbital feed and screw-pitch on form error and surface roughness. It is shown that the orbital drilling approach is feasible to machine the hole of hardened steel with smooth surface and little burrs using an AlTiN coating WC drill bite. Moreover, the hole form accuracy and surface roughness can be improved with increasing the tool speed and the working space, or decreasing orbital speed and orbital pitch. It is also found that the hole edge burrs can be reduced by choosing a low orbital speed. It is indicated that the form error may be greatly decreased by using a compensation approach through a new CNC tool orbital path.
Mechanical Properties and Experimental Study of a Composite Polishing Plate during Super-High Polishing
Authors: Zhou Li , Huang Shu Tao , Xu Li Fu
Published: October 2010

A new composite polishing plate for polishing of CVD diamond films has been designed. The displacement and stress distributions of the high speed rotation polishing plate have been investigated due to centrifugal forces, and the polishing mechanism of super-high polishing has been analyzed by using X-ray photo-electron spectroscopy. The results showed that the displacements both in axial and radial increase with the increasing of the rotational speed. When the rotation speed reached to 1200 rad/s, the von Mises equivalent stress is about 242 MPa, which is safe for the composite polishing plate. Additional, the polishing mechanism is mainly the chemical reaction between carbon and titanium during the super-high speed polishing. At elevated temperature, the chemical reaction between oxygen and titanium, oxygen and carbon can also occur.
Study on Surface/Subsurface Crack Mechanism in Ultrasonic Vibration Added Grinding of Ceramics
Authors: Zhao Bo , Kong Ling Zhi
Published: October 2010

Because of the high hardness and high brittleness of ceramics, crack damage would be easy left in the finished surface. This will lower the reliability of ceramics parts. Studies show that Ultrasonic vibration Added Grinding (UAG) can greatly improve the surface quality, but how UAG to reduce the surface/subsurface damage isn’t very clear. To this purpose, the surface/subsurface crack mechanism of the ultrasonic vibration added grinding on ceramics was mainly analyzed in this article. The study shows that ultrasonic vibration can change the crack propagation direction to free surface, rather than propagate to the deep material which will happen in conventional grinding. And this will reduce the surface/subsurface crack defects.
Optimal Design of Rotary Ultrasonic Vibrator and Research on its Machining Experiments
Authors: Tang Yong Jun , Chen Chun Mu , Zhang Yong Jun , Liu Guo Yue
Published: October 2010

In order to obtain well work performance, a new design process and the optimal method are systemically presented during ultrasonic vibrator’s design. Firstly, the general dimensions are calculated according to formula of ultrasonic theory. Secondly, 3D model without flange is established, and the best position setting a flange has been conformed through finite element analysis (FEM). Then constraints are laid on the flange, and the best model of vibration is obtained based on model analysis. The results are benefit to the following control design of ultrasonic vibrator. Finally, an ultrasonic vibration system has been made, and a series of experiments validate the feasibility of the design method.
Optimization of Segmented Grinding Wheel Matrix Based on Super High-Speed Grinding
Authors: Zhang J.Q. , Pang Zi Rui , Guan P. , Wang Wan Shan , Pi H.Z.
Published: October 2010

It is different from the traditional integrated super high-speed grinding wheel, the centrifugal force has greater impact on segmented grinding wheel in super high-speed rotation. In this paper, in order to ensure the safety of super high-speed grinding wheel, models for the connection between inner micro-unit’s displacement and stress of wheel matrix were established to optimize high-speed grinding wheel section form, reduce the centrifugal stress and control the radial displacement of grinding wheel. Consider the structural and mechanical characteristics of wheel matrix, strength check of the theoretical formula were also established. Taking into account the factors of aerodynamic and wheel connector effects, at last the design of segmented super high-speed grinding matrix was optimized with finite element method.
Convex-Shape Tool in Nano-Fabrication of Digital-Paper Display
Authors: Pa Pai Shan
Published: October 2010

This study describes a new module that uses micro electrochemical machining, and a new design of a convex-shaped tool, in a precision reclamation process to remove defective Indium-tin-oxide (ITO) nanostructures from the optical PET diaphragm surfaces of a digital-paper display. This process takes very little time to remove the ITO layers easily and cleanly and is highly efficient both technically and economically. A small end radius of the cathode or a thin cathode of the bulge-form tool takes less time for the same amount (20 nm) of ITO removal. A large diameter of the cathode of the bulge-form tool combined with a small gap between the cathode and the workpiece corresponds to a higher removal rate of ITO. A high rotational speed of the bulge-form tool can also improve dregs discharge and allows a higher feed rate of the optical PET diaphragm. This higher feed rate combined with enough voltage results in a shorter machining time.
The Measurement of the Velocity Outside the High Pressure Water Jet and Abrasive Water Jet Nozzle Based on the Energy Transfer Method
Authors: Hou Rong Guo , Huang C.Z. , Zhu H.T. , Niu Z.W.
Published: October 2010

The energy transfer method is used to measure the flow velocity of the outside the high pressure water jet (WJ) and Abrasive water jet (AWJ) nozzle. The impact forces of the flow measured by the piezoelectricity ergometer will be transformed to the velocity value, the average velocity of the flow outside the nozzle will be obtained. The result indicates the velocity will reduce along the direction of the flow, and the velocity of the AWJ flow will reduced greatly than the WJ flow, which indicates that the length of the core part of the AWJ flow is shorter than the WJ Flow, the stand-off should be within the 0mm-15mm ranges to gain the most effective machining.
Influences of Properties of Fixed Abrasive Tool on the Lapping Process of Stainless Steel Substrate
Authors: Zhu Cong Rong , Lv Bing Hai , Yuan Ju Long
Published: October 2010

To improve the machining efficiency as well as surface roughness, a series of experiments employed fixed abrasive tools are carried out for stainless steel substrate, and influences of properties of fixed abrasive tool on the lapping process are studied. It is found that the resin is the best bonding material in this study. The surface roughness under different concentration of bonding material is similar, and the material removal rate (MRR) increases as the concentration of bonding material decreases from 50% to 20%. But too little of bonding material results into low bond strength that causing low material removal rate. It is also found that higher shear strength, lower wear rate, and the shear strength of the tool with 35% bonding material is the highest. It is obvious that the surface roughness and material removal rate decline as the grit size decreases. The roughness of surface lapped with resin bonded 4000# SiC abrasive tool comes to 18nm, and the material removal rate is 0.63μm/min.
Modeling the Material Removal Rate in Micro Abrasive Water Jet Machining of Glasses
Authors: Fan Jing Ming , Fan Chang Ming , Wang Jun
Published: October 2010

Micro abrasive water jet (MAWJ) machining is a new promising micro machining technology for brittle material. The rate of material removal is one of the most important parameter for abrasive processes. Predictive mathematical model for the material removal rate is presented for micro channel machining by micro abrasive water jet (MAWJ). A dimensional analysis technique is used to formulate the model. The validity and predictive capability of the models are assessed and verified by an experimental investigation when machining glasses. It shows that the predictions of the models are in good agreement with the experimental data.
Modeling of Thickness of the Oxide Film in ELID Grinding
Authors: Zhang Hua Li , Kuai Ji Cai , Zhang Fei Hu
Published: October 2010

The properties of oxide films are very important for improving the mass of ELID grinding surface. In this paper, a novel calculation model of thickness of oxide films was proposed; the theoretical calculation and simulation analysis were developed, and were compared with the corresponding experimental results. The results proved that the theoretical calculation and simulation results of the thickness of the oxide films had good agreement with the experimental results. This model could predict precisely the change of thickness of oxide film, the instinct of non-linear electrolysis was explained from a novel aspect of ability of pulsed electrolysis. This model could be used in the on-line control of electrolytic state during practical ELID grinding process.
Preparation of Magnetic Abrasive by Sintering Method
Authors: Zhao Zeng Dian , Huang Yu Hong , Zhao Yu Gang
Published: October 2010

In this paper, ferrosilicon powder was used as the ferromagnetic phase, corundum powder as the abrasive phase, high temperature inorganic binder as the adhesive, and after the ferrosilicon powder was modified, a series of magnetic abrasive was obtained by sintering method. Scanning electron microscope (SEM) and Energy dispersive spectrometer (EDS) were respectively used to characterize the morphology and elemental composition of magnetic abrasive. and through experiments carried out on the magnetic abrasive grinding performance testing and durability analysis. The experimental results showed that the magnetic abrasive prepared had good polishing ability and longer using time, and the surface roughness of the grinding sample can reach 0.12μm and the using time is up to 25 min.
Development of High Performance Monolayer Brazed Diamond Grinding Tool for Ceramics
Authors: Zhang Bei , Xu Hong Jun , Fu Yu Can , Su Hong Hua
Published: October 2010

This study has developed a new kind of high performance monolayer brazed diamond tool for ceramic grinding. The grit size of the diamond brazed in the grinding wheel surface is 300m, which has never been reported in diamond tools for ceramic precision machining. The experiment has achieved wonderful surface finish of Zirconia workpiece. This does owe to the designed and precision conditioned topography of the new developed grinding wheel. The topography of the grinding wheel before and after dressing has been measured by means of laser triangulation method. Then the Zirconia workpiece has been ground. The obtained Ra value decreases with no spark grinding times and the minimum Ra of the ground surface is 0.11m. The study proved that the brazed large grit diamond tools would realize high efficiency and precision grinding, namely, high performance of ceramic grinding.
Modification of Resin and its Application to Resin-Bonded Diamond Wire Saw Manufacture
Authors: Bi Wen Bo , Ge Pei Qi , Song S.Q. , Gao Y.F. , Wang Z.S. , Zhang L.
Published: October 2010

The purpose of this paper is to modify the resin binder for developing resin-bonded diamond wire saw. The optimization of components with different ratios in the resin binder was investigated using orthogonal design experiments. Besides, the resin-bonded diamond wire saw was developed using the piano wire (the diameter is 0.2mm), the modified resin and the diamond abrasive (the diameter is 20~30μm). Good surface quality and slicing performance were obtained when slicing silicon crystal using the resin-bonded diamond wire saw we made in the experiments.
Fillers and Dissolvent in Porous Self-Generating Fine Super-Hard Abrasive Tool
Authors: Fan Hong Wei , Lv Bing Hai , Yuan Ju Long , Deng Q.F. , Yao W.F.
Published: October 2010

In order to obtain low surface damage and high machining efficiency for advanced ceramics, overcome clogging and dressing difficulties of traditional metal bonded super-hard abrasive, a novel fine super-hard abrasive with porous self-generating ability is proposed in this paper. And the matching of filler and dissolvent in abrasive are studied. Soluble filler is a key technology of porous self-generating fine super-hard abrasive. In this paper, metal, metal oxide and non-metallic oxide are respectively used as soluble fillers. Results of the experimental shows: In metal bonded super-hard abrasive, metal, metal oxide and non-metallic oxide as soluble filler are feasible, correspondingly, FeCl3 solution, aqueous solution and weak alkaline solution are used as dressing dissolvent, respectively. It can be met the requirement of high precision machining for advanced ceramic materials, hard and brittle machining materials.
Study on Heavy CNC Belt Grinding Technology of High Precision Controllable Pitch Propeller
Authors: Huang Zhi , Zhang Lei , Huang Yun , Wu Jian Qiang
Published: October 2010

A high-precision grinding method is presented to the marine controllable pitch propeller. Developed the four-axis simultaneous grinding system based on the abrasive belt grinding principle, and studied the key technologies of the grinder, such as the heavy-duty belt grinding head, the controllable pitch propeller grinding CNC programming software, etc. And on these bases, we have done the four-axis simultaneous heavy belt grinding test verification on the surface of the controllable pitch propeller blade with the grinder, providing a reference to determine the reasonable marine propeller belt grinding process parameters.
Discussion on Laser Cleaning of Optical Surface Machined by Magnetorheological Finishing
Authors: Kang Gui Wen
Published: October 2010

Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. Through proper designing of numerical control, sphere and asphere optics can be machined by magnetorheological finishing with high quality. Owing to it’s excellence in optical manufacturing, MRF has gained more and more application in industry. Under most conditions the optical surface after MRF would have certain contaminant particles and this would affect its working ability in future use. Formerly the polished workpiece is cleaned by flowing water or ultrasonic cleaning and the contaminat particles couldn’t be totally removed. Laser cleaning is brought forward in this paper and good results could be anticipated.
Geometric Modeling for Five-Axis CNC Machining of Mold Surface with Flat-End Tool
Authors: Gao Wei Qiang , Xie Bo , Huang Zou Ya , Qing Chao Ting
Published: October 2010

This paper taken the flat-end tool and machined surface as a pair of mutually conjugate space contact tooth envelope surface and used the Frenet frame of differential geometry to describe the NC machining tool path in five-axis CNC machining of mold surface with flat-end tool. Thus the geometric model in five-axis CNC machining of mold surface with flat-end tool was established.
Research of Electrochemical Polishing Mixed with Powder and Related Experiments
Authors: Zhang Yong Jun , Tang Yong Jun , Li Feng
Published: October 2010

In order to resolve the problem of polishing micro-shafts and cavities, a novel technique of Micro-Electrochemical Polishing Mixed with Powder (EPMP) has been presented in this paper. That can be accomplished through high speed spindle driving micro-abrasive to proceed soft-grinding, which can achieve merit of little polishing force. The principle of EPMP has been introduced, and a series of issues have been studied. Finally, experiments of EPMP have been carried out based on above optimized machining parameters, and a micro-screw-shaft of Φ100μm has been polished. Which is near to mirror effect (Ra=0.02μm).
Process Parameter Optimization and Experiment Study of Aero-Engine Blade in Electrochemical Machining
Authors: Li Zhi Yong , Niu Zong Wei
Published: October 2010

Because the process of blade in electrochemical machining(EMC) can be effected by many factors, such as blade shapes, machining electrical field, electrolyte fluid field and anode electrochemical dissolution, different ECM machining parameters maybe result in great affections on blade machining accuracy. Regard some type of aero-engine blade as research object, five main machining parameters, applied voltage, initial machining gap, cathode feed rate, electrolyte temperature and pressure difference between electrolyte inlet and outlet, have been evaluated and optimized based on BP neural network technique. From 3125 possible machining parameter combinations, 657 optimized parameter combinations are discovered. Furthermore, the final optimized ECM process parameters have been obtained. To verify the validity of the optimized ECM parameter combination, a serial of machining experiments have been conducted on an industrial scale ECM machine, and the experiment results demonstrates that the optimized ECM parameter combination not only can satisfy the manufacturing requirements of blade fully but has excellent ECM process stability.
Study on Effect of Gases as Coolant and Lubricant on Machined Surface
Authors: Zhang Yue , Han Li , Sun Tai Li , Liang Quan , Zhang Xi Chuan
Published: October 2010

To investigate the effects of gases as coolant and lubricant on machined surface, the micrograph and roughness value were obtained face to green cutting. Under the experiment conditions, water vapor and nitrogen gas may give a better restrain action to nubs adhibiting on the machined surface. And water vapor gave the lowest roughness value, while nitrogen gas has hardly help to lower roughness value. Other gases, only at a certain extent, can restrain nubs adhibiting and lower roughness value. Common characters of these gases are widely source, out of pollution, needless to disposing and so forth. With the view point of environment friendly, these gases may achieve green cutting.
Mathematical Model of Hydrodynamic Fluid Pressure on Smooth and Real Surface
Authors: Li Chang He , Wang Li Li , Liu Guo Yu
Published: October 2010

Conventional method of flood delivering coolant fluid by a nozzle in order to achieve high process performance. However, hydrodynamic fluid pressure can be generated ahead of the contact zone due to the wedge effect between wheel peripheral surface and work surface. In the paper, theoretical hydrodynamic pressure modeling were presented for flow of coolant fluid through the grinding zone in flood delivery grinding using smooth and roughness surface grinding wheel respectively. The simulation results show that the hydrodynamic pressure was proportion to grinding wheel velocity, and inverse proportion to the minimum gap between wheel and work surface and the maximum pressure value was generated just in the minimum gap region in which higher fluid pressure gradient occuring. It can also be concluded the surface roughness of grinding wheel and workpiece makes the contact zone’s hydrodynamic pressure rough and unstable, i.e. the value curve considering roughness is not smooth, leading to the micro-elastohydrodynamic lubrication phenomenon.
Coupled Thermal-Structural Finite Element Simulation of Ti-6Al-4V Alloy during Electrical Discharge Machining
Authors: Wang Yan , Gao Feng
Published: October 2010

Theoretical models of temperature and thermal stress for Ti-6Al-4V during electrical discharge machining (EDM) process are established. Based on finite element method, the temperature field of EDM Ti-6Al-4V alloy is simulated firstly with the aid of ANSYS, the results can be used to predict the width and depth of the spark crater. The simulated results show that there is a high temperature distribution at the spark point while the zone is quite small. The thermal stress field is estimated using the results of the temperature field as input. Surrounding the spark crater, the thermal stresses are concentrated, where may cause micro-cracks.
Research on Minimum Mechanism of Roughness of ELID Grinding
Authors: Kuai Ji Cai , Zhang Hua Li , Zhang Fei Hu , Zhang Yong
Published: October 2010

ELID grinding technology is used widely in the precision grinding of hard and brittle materials. The nature of passivating film play an important role in ELID mirror grinding. Spring’s stiffness of passivating film was researched from theory and simulation and experiment. And the theory of the dynamic stiffness of spring was proposed, based on this theory minimum mechanism of roughness of ELID grinding was proposed further, and experimental verification was done. Results show, the spring stiffness of passivating film is change with the grinding paramenter, and when implementing the precision grinding, the elastic deformation of oxide film reduces the exposure and grinding depth of the grinding grains, accordingly, ameliorating the grinding surface quality.
Study on Electrolysis Performance of Bamboo Charcoal Bonded Grinding Wheel
Authors: Li Wei , Wu Jian , Geng Bao Gong
Published: October 2010

Electrolytic in-process dressing (ELID) Grinding was an effective machining method for gaining of super smooth surface for hard and brittle materials due to its excellent surface generation capabilities. Bamboo charcoal bonded (BCB) grinding wheel was an environmental friendly ELID grinding wheel which was made up of bamboo charcoal and phenolic resin as bonding agent with high temperature sintering process. In this paper, the electrolysis performances of the BCB grinding wheel with the different resin ratios were researched, and the surface of BCB grinding wheel formed a dense oxide layer in electrolysis action, was illustrated with SEM and XRD analysis.
Study on Properties of Grinding Fluid Jet and Nozzle Position for Super-High Speed Point Grinding
Authors: Xiu Shi Chao , Luo Ji Man , Sun Zhi Li
Published: October 2010

Super-high speed point grinding is a new high-speed grinding technology with some excellent machining performances. In such a grinding process, there is a high-speed airflow rotating around the edge of grinding wheel which hinders the grinding fluid from injecting into the contact area and makes the fluid atomization and splash during grinding process, so as to decrease the ratio of effective grinding fluid into contact area and affect the surface integrity of workpiece. In this paper, the structure and properties of grinding fluid jet is analyzed, the velocity distribution field of the round turbulent jet is discussed theoretically and simulated. Based on the pressure balance principle, a mathematical model is established for the jet velocity at the fluid nozzle, which enables the grinding fluid to pass through the high speed airflow and enter into the contact area. According to the analysis of the grinding fluid velocity in the jet core, an engineering formula is given to calculate the position limit of nozzle during grinding process, as well as a practical design example for the high speed grinding machine is presented.