bluuebunny/crossref_metadata_2025 huggingface dataset:
Homogenization Behaviors of Low Frequency Electromagnetic Casting and Direct Chill Casting 7050 Aluminum Alloy
Authors: Zhao Zhi Hao , Cui Jian Zhong , Wang Jing , Wang Gao Song
Published: March 2010

7050 aluminum alloy ingots were produced by low frequency electromagnetic casting (LFEC) and direct chill casting (DC) respectively. As-cast microstructures and homogenization behaviors of LFEC and DC ingots were investigated experimentally. The optical microscope and DSC analyses shown that the grain size of LFEC ingot was finer and the content of constituents and eutectic structure was less than that of DC ingot. Accordingly, the homogenization behaviors of the LFEC and DC ingots were significantly different. The remnant constituents of LFEC ingot were less in content and smaller in size than that of DC ingot after homogenization at 480°C for various lengths of time. Similar to the dissolving of constituents, the LFEC ingot exhibited faster diffusion kinetics of alloying elements from grain boundary to inner. The concentrations of Cu, Mg and Zn inside grain of LFEC ingot after homogenization for 12 h were 2.4%, 2.2% and 6.5% respectively, but the DC ingots had not reach the level even for 48 h.
Study on Size and Microstructure of Complex Cavity Aluminum Alloy Castings Formed by Pre-Burying Copper Pipe Core
Authors: Yan Qing Song , Yu Huan , Xu Zhi Feng , Cai Chang Chun , Xiong Bo Wen , Zheng Yu Hui
Published: March 2010

The feasibility of especial technology which complex cavity aluminum alloy castings are formed by corroding pre-burying copper pipe core is discussed by researching on the size and microstructure of cavity formed by corroding pre-burying copper pipe core. The results indicate the size of cavity formed by corroding pre-burying copper pipe core is basically consistent with the original size of the castings, with a dimensional tolerance in permission scope which is about 0.01mm. Meanwhile, the microstructure of cavity wall formed by corroding pre-burying copper pipe core is identical with that of the castings without corrosion. Moreover, because the pre-burying copper pipe core is equal to the chilled iron, bringing cold effect, the crystal grain of cavity wall formed by corroding pre-burying copper pipe core are tinier. Therefore, the technology of using pre-burying copper core to form complex cavity of aluminum alloy casting is entirely feasible.
Positron Annihilation in Ion-Implanted ZnO
Authors: Acharya Aman Deep , Singh Girjesh , Shrivastava S.B.
Published: March 2010

The Diffusion Trapping Model has been used to obtain the positron annihilation Doppler broadening lineshape parameter in ZnO and O+, B+, N+, Al+ implanted ZnO films. The concentration of vacancy clusters is found to be related to the atomic number and the fluence of the implanted ion. The S-parameter is found to be largest in the case of implantation of Al+ ions and is minimum for the implantation of B+ ions. Thus, the vacancy clusters are found to be largest in the case of Al+ implantation. The calculated results have been compared with the experimental value.
Research on Magnetization Mechanism of Nano-Magnetic Fluid
Authors: Li Jian Ling , Li Decai
Published: March 2010

In this paper, we first analyzed the nano-magnetic fluid composition and properties. Then we studied the characteristics of nano-magnetic fluid magnetization and magnetization mechanism. In addition, we also studied the nano-Fe3O4 magnetic particle size and surface modification effect on the magnetic properties of magnetic fluids. Nano-magnetic fluid is a new type of liquid nano-composite functional material. It also has magnetism and mobility, and therefore it has many unique properties and a wide range of applications. Nano-magnetic fluid magnetization characteristic is one of its main properties, its performance and application of magnetic fluid play a decisive role.
Stress-Induced Migration and Trapping of Hydrogen in AISI403 Steel
Authors: Tiwari G.P. , Alur V.D. , Ramadasan E.
Published: March 2010

This paper presents hydrogen concentration profiles in notched tensile test specimens which have been charged electrolytically with hydrogen, with and without the application of a tensile load. A standard 8mm ASTM tensile specimen, extended at one end, is employed. This extended portion serves as a cathode during electrolytic charging. In order to facilitate the application of a load during charging, the specimen is firmly held in a specially designed fixture with the help of threads that are provided on each end of the gauge section. A notch is provided, in the gauge section, to create a stress gradient. At the end of charging, 3mm-thick disc specimens are cut from the specimen and analyzed for their hydrogen content using the inert gas fusion technique. The results show that the presence of tensile stress enhances the rate of hydrogen ingress as well as the net hydrogen concentration in the matrix. In the absence of stress, diffusion down the concentration gradient controls the hydrogen distribution within the specimen. Surface area plays an important role in the accumulation of hydrogen across any section in the specimen. If the available surface area is greater, the local hydrogen concentration is enhanced. Sheathing of the charging section with a 3mm-thick jacket of pure uranium causes a significant improvement in the hydrogen concentration along the entire length of the specimen. However, the presence of a 100µm-thick coating of titanium in the charging section of the specimen did not cause any significant change in the hydrogen concentration of the specimen.
The main advantage of this charging procedure is that the test portion of the specimen does not come into contact with the electrolyte, and the hydrogen reaches the test portion of the specimen via diffusion through the matrix. Hence, microstructural damage to the specimen during the entry of high-fugacity hydrogen into the matrix is avoided.
Electromigration Force on a Proton with a Bound State
Authors: Lodder A.
Published: March 2010

The driving force on an ion in a metal due to an applied electric field, called the electromigration force, is built up out of two contributions, a wind force and a direct force. The wind force is due to the scattering of the current carrying electrons off the ion. The direct force works on the effective charge of the ion. In the present work we concentrate on the direct force on a migrating proton embedded in an electron gas. For this force a sign change is obtained as soon as a bound state is formed. In recent calculations hardly a sign change was seen, although a bound state was found in a self-consistent-potential for lower electron densities. Here we show that a supplementary term shows up, as soon as one accounts for the bound state explicitly. By this the problem has been solved regarding a possible lack of completeness of the published formalism. The results presented are based on square-well model potentials. By using different depths it is possible to show results for potentials without a bound state and accommodating one bound state.
Fiber Bridging Effect on In-Plane-Shear Mode Crack Extension Resistance of Unidirectional Fiber-Reinforced Composites
Authors: Sekine Hideki , Kamiya Shoji
Published: March 2010

The fiber bridging effect, which affects the crack extension resistance in fibrous composites, is discussed in the case of in-plane-shear mode crack extension parallel to fibers in unidirectional fiber-reinforced composites. We first make a model of the bridging of a single fiber and estimate the force acting on the crack surface through a bridging fiber. Then, introducing the stochastic process of fiber breakage, we obtain the quantitative relationship between the relative crack surface displacement and the equivalent cohesive stress which is the probabilistic expectation of forces acting on the crack surface through a large number of bridging fibers. We numerically simulate the crack extension behavior with the equivalent cohesive stress acting on the crack surface. Then the simulated results are consistent with the experimental results. We finally conclude that the in-plane-shear mode crack extension is greatly affected by the stochastic process of fiber breakage.
FEM Simulation on the Temperature Distribution of Ice Fixed Abrasives Polishing
Authors: Sun Yu Li , Zuo Dun Wen , Lu Wen Zhuang , Zhao Yu Fei , Kang Jing , Wang Min
Published: March 2010

The key question in the ice fixed abrasives (IFA) polishing is how to keep suitable ambient temperature in production process in order to avoid premature failure of the IFA. Based on above, the three dimensions finite element analysis (FEA) model of IFA polishing temperature field is built up at first. Then, the model reliability is demonstrated by experiments. Effects of ambient temperature and polishing time on temperature distribution and melting rate of the IFA pad are researched. The results show that the ambient temperature should be kept at about 10 °C in order to control the melting rate of the IFA pad effectively and keep longer polishing time. All the results provide the basis for choosing suitable ambient temperature in polishing.
A New Fuzzy Backorder Inventory Model for the Decision Making of Material Inventory in the Manufacture System
Authors: Chou Chien Chang
Published: March 2010

Inventory management is one of important issues in the manufacture system. Thus, this paper proposes a new fuzzy approach to solve the inventory management problems in the manufacture system. In the past, few papers discussed the square roots of fuzzy number. The square roots of fuzzy number can be applied to solve the optimal inventory quantity problems in the fuzzy manufacture system. This paper first proposed the square roots of fuzzy number. Finally, the square roots of fuzzy number are applied to obtain the optimal order quantity for the fuzzy backorder inventory model in the manufacture system.
Simulation and Control Models of Laser Bending Angle of Sheet Metals
Authors: Zhang Peng , Liu Hong Wei
Published: March 2010

Laser bending process of sheet metals is a highly flexible forming technique. Simulate model of laser bending process was established by dimension analysis, and the control model of laser bending was achieved with the regression of swatch datum. It was shown that dimension analysis was an effective method in simulating the complex laser bending process, and the control model, which came from non-dimension group datum, was a high-accuracy model in predictive analysis of bending angle.
Evaluation of Heuristics for a Resource-Constrained Project Scheduling Problem
Authors: Zhong Shi Sheng , Fu Xu Yun , Lin Lin , Wang Guo Lei
Published: March 2010

The resource-constrained project scheduling problem (RCPSP) exists widely in engineering. There have been many heuristics for the RCPSP, therefore, how to evaluate them and then choose a proper algorithm, is a focus issue recently. This paper presents a new evaluation method of heuristics for a special RCPSP based on activity-on-the-node networks. The method is aimed at finding at the regression equation between network measures and a performance measure. Technical details of the method, which include the design of a random network generator, the definitions of network measures and its concrete steps, are discussed. A case study in an electric machinery manufacturing enterprise illustrates that the evaluation method is good practice.
Research on the Influence of Cutting Fluids on the Critical Depth of Cut in Diamond Cutting of Optical Glass BK7
Authors: Zhou Ming , Jia Peng , Li Min
Published: March 2010

In diamond cutting of optical glasses, the magnitude of critical depth of cut for brittle-ductile transition is an important factor affecting the machinability of the work material in terms of production rate and surface quality. In this work, scratching tests with increasing depths of cut were conducted on glass BK7 to evaluate the influence of the cutting fluid properties on the critical depth of cut. Boric acid solutions of different concentrations were selected as cutting fluids in the tests. The resulting scratches were examined utilizing a white light interferometer and the values of the critical depth of cut were determined based on the observations of the micro-morphology of the scratch surfaces produced. Experimental results indicated that compared with the process without cutting fluid action, the critical depth of cut in diamond cutting of glass BK7 can be increased by using boric acid solution as the cutting fluid.
Simulation of Microstructure Evolution Coupled with Fabrication Temperature for Two-Phase Ceramic Tool Materials
Authors: Fang Bin , Huang Chuan Zhen , Xu Chong Hai , Sun Sheng , Zou Bin
Published: March 2010

A computer simulation coupled with fabrication temperature for the sintering process of two-phase ceramic tool materials has been developed using a two-dimensional hexagon lattice model mapped from the realistic microstructure. The relationship between fabrication temperature and microstructure evolution is proposed. The mean grain sizes of simulated microstructures by Monte Carlo Potts model integrated with fabrication temperature increase with an increase in fabrication temperature, which is consistent with the experiment results.
Research on Simulating and Modeling Method for Spiral Bevel Gears with Actively Controllable Contact Patterns
Authors: Yao Bin , Zhang De Yun , Mao Shi Min
Published: March 2010

An innovative modeling method of spiral bevel gear is presented in detail for actively controllable contact patterns. Firstly the 3D model gear of is given, and then creates its modified model by analyzing the contact patterns of work condition. Lastly, being based upon meshing theory, the modified gear moves relatively to the pinion blank, and simultaneously carries out Boolean Subtracting on the pinion blank, which is the modeling process of a pinion’s tooth surfaces. With this method, modeling of spiral bevel gears is more convenient to get, and gear contact patterns is easier to control actively.
Diamond Tool Wear Mechanism in Ultra-Precision Turning of SiCp/Al Composites
Authors: Ge Ying Fei , Xu Jiu Hua
Published: March 2010

The wear pattern and its mechanisms of Single Crystal Diamond (SCD) tool has been investigated experimentally and theoretically during ultra-precision turning of SiC particle-reinforced aluminum matrix composite. The results showed that micro wear, chipping, peeling, abrasive wear and chemical wear were the dominating wear patterns of SCD tools. Coupled with XRD analysis on the machined surface and Raman studies on the flank wear land of SCD tool, it was pointed that the combined effects of abrasive wear of SiC particles and catalysis of copper in the aluminum matrix have caused the severe graphitization.
Quasicontinuum Simulation of Effect of Crystal Orientation and Cutting Direction of on Nanometric Cutting of Single Crystal Copper
Authors: Pen Hong Min , Bai Qing Shun , Liang Ying Chun
Published: March 2010

Quasicontinuum simulation of nanometric cutting was conducted on single crystal copper to investigate the effect of crystal orientation and cutting direction on nature of deformation of this material. The model reduces the degrees of freedom in simulations of nanometric cutting process without sacrificing important physics. The simulation results show the crystal orientation and cutting direction have a significant effect on the nature of deformation of nanometric cutting process. In addition, the variations of strain energy of workpiece atoms in different crystal set-ups are investigated.
Study on Performance and Mechanism of High Efficiency Organic Grinding Liquid for Ceramics with Silicon
Authors: Tian Xin Li , Yang Jun Fei , Liu Chao , Guo Fang , Yu Ai Bing
Published: March 2010

This study selected three types of organic substance as the main components of high-efficient organic grinding liquid for grinding ceramics with silicon. The grinding efficiency test was conducted on the basis of self-developed grinding mechanism and the findings indicated that the grinding performance of all these three types of grinding liquid were better than average grinding liquid. With Si3N4 Ceramics as the representative test material, the grinding efficiency can be increased at least 1.37 times and more than twice with the grinding fluid prepared with oleic acid or oleic alcohol. The analysis of liquid-solid interface with the help of infrared spectrum showed that there existed abnormal vibration peaks in the liquid-solid interface between Si3N4 ceramics and grinding liquid with (organic substances)–OOH and －OH under normal temperature, which resulted from the adsorption effect of hydrogen bond generated between organic molecule and Si3N4 ceramics. Under high grinding temperature, the friction chemical reaction took place as the result of the absorption effect and the resultant could not only reduce the surface hardness, but also improve the lubricating effect, thus improving the grinding efficiency and surface quality.
Analysis and Study on Single Physics Field and Coupling Field of Cutting Tools for Machining Carbon Structural Steel
Authors: Cheng Yao Nan , Li Zhen Jia , Gao Jun , Zhao Yong Gang
Published: March 2010

Based on the experiments on milling the carbon structural 45 steel with the flat rake milling insert and the waved-edge milling insert, the analysis and study on single physics field and coupling field are studied. On the basis of the milling force and milling temperature mathematical models, the force density function and heat density function of the waved-edge milling insert are built, the stress fields analysis and temperature fields analysis have been done. In order to discuss the distribution principle of equivalent stress and distortion under coupling condition, the coupling analysis on the stress field and temperature field is done. All these studies provide the theoretic and experimental basis for solving the cutter disrepair and groove optimization technology.
A Product Information Model for Web-Based PDM System Using Ontology
Authors: Zhang Yong Jian , Zhong Shi Sheng , Lin Lin
Published: March 2010

The complex engineering project has properties of long time lasting, enormous data amount and wide range of interoperation. To support effectively data management in both different product lifecycle phases and across different systems through web PDM system, ontology based product information model was developed. The model includes concept part for common manage and domain part for specific industries. Concepts and relations were built and introduced. Using ontology improved the machine interoperability. The developed model is validated by the application to the practical web PDM system of enterprise project.
Research on the Stress Intensity Factor of the Crack Inclined across the Interface of Cermet Cladding Parts
Authors: Yang Jun Ru , Li Zhao Qian , Huang Chuan Zhen , Wang Quan Wei
Published: March 2010

Basing on the theoretical study on the stress intensity factor (SIF) of the crack inclined across the interface of the cermet cladding part, the finite element analysis (FEA) of the crack’s SIF is made. The change laws of the SIF with the load action angle , the load Q, the clad thickness ratio h1/h, the elastic modulus ratio E1/E2, the inclined angle of the crack β1, and the crack length ratio a1/a2 are obtained. The research results have theoretical and steering significance on the wide application of the cermet cladding part.
Investigation on White Layer Formation in PCBN Hard Turning GCr15
Authors: Qi Bao Yun , He Ning , Li Liang , Zhao Wei
Published: March 2010

It is commonly believed that the white layer formed during hard machining of steels is caused primarily by a thermally induced phase transformation resulting from rapid heating and quenching. The focus of this study is to investigate the white layers produced on the machined surfaces and on the inner side part of the chips in dry hard turning GCr15 with PCBN tools. Samples of machined workpiece and chips were metallographically processed and observed under a microscope to determine whether white layers were present or not. Some properties of white layers were deduced in order to verify some of the prevalent theories. More specifically, chip shapes were studied to determine how they developed during machining with potential appearance of white layers, with a view to correlating the chip shapes with the white layer formation.
Study of PCBN Cutting Tools Wear in High Speed Cutting Hardened Steel GCr15
Authors: Wang Yu , Zhai Yuan Sheng , Yan Fu Gang , Liu Xian Li
Published: March 2010

PCBN cutting tools is in high speed, high temperature and high pressure environment when high speed precision hard cutting hardened steel. Shear extrusion and slip effect in high speed cutting, cutting tools wear mechanisms are different from common cutting, even cutting tools wear mechanisms in high speed is in research stage at present. In this paper, coated PCBN cutting tools wear mechanisms in high speed cutting(v＝200~600m/min) GCr15 (HRC62-64) is studied, it is helpful to obtain cutting tools structure design, cutting parameters and improve cutting tools use efficiency.
Tool Wear State Diagnosis Based on Wavelet Analysis-BP Neural Network
Authors: Fan Ning , Liang Hang , Guo Pei Quan
Published: March 2010

Cutting force collected by experiment is transformed by continue wavelet in order to overcome the disadvantage that signal processing analyzes single variable. The eigenvector which can reflect tool wear state is extracted from scale-energy matrix based on analysis, and BP neural network is established to predict tool wear. Trained network is used for prediction by unknown sample. Results show that this method can identify and diagnose accurately tool wear state.
Experimental Investigation and CFD Simulation of Removal Characteristics in Nanoparticle Colloid Jet Machining
Authors: Song Xiao Zong , Zhang Yong , Zhang Fei Hu , Luan Dian Rong
Published: March 2010

A computational fluid dynamic (CFD) model for submersion jet has been developed to investigate the hydrodynamics in nanoparticle colloid jet machining with small diameter nozzle about 0.21mm. With this model, the fluid field characteristics and pressure distributions in the system are computed under the condition of vertical injection and aslant injection when jet pressure is 4MPa. The corresponding material removal experiments in nanoparticle colloid jet machining have been done to validate the rationality of the CFD model. And the simulated data are in good agreements with the experimental results.
A New Method of Pulse Technique in Gasbag Polishing
Authors: Ji Shi Ming , Zhang Wei Dong , Jin Ming Sheng , Zhang Li , Zheng Gao An
Published: March 2010

Gasbag polishing is an automatic, flexible, controllable and practical technique, which has wide application prospect. A pulse technique based on robotic gasbag polishing system is proposed. Its main principle is to use the Pulse Width Modulation (PWM) technique to control the switching time of High-speed Solenoid Valve (HSV). It can not only control the internal pressure of gasbag, but also make the rubber gasbag present pulsation with PWM technique. Moreover, the performance of pulse technique is presented and the effects of different frequency pulse pressure on the polished surface roughness are analyzed through a series of experiments. At last, experimental results show that the pulse technique can improve the polished surface roughness more rapidly in certain extent with appropriate pulse frequency and process parameters comparing with conventional gasbag polishing way.
Explicit Finite Element Simulation of Oblique Cutting Process
Authors: Guo Jian Ying , Lv Ming
Published: March 2010

An explicit dynamic model of oblique cutting is presented. The explicit solid elements with one-point integration Lagrange algorithm were adopted, and elastic viscoplastic with thermal effect material model was used in simulation. The automatic surface to surface tiebreak contact type was employed to simulate the chip separation from workpiece. The model solves the mesh distortion caused by large deformation, so the simulation results can reveal the shearing slip phenomenon of chip material from the deformation of elements. The shape of deformed chip and the temperature distribution in chip and tool are obtained. The calculated specific cutting power are compared with published experimental data and found to be in good agreement.
Experiment and Prediction of Grinding Force on the Design of a CAM Dental Restoration System
Authors: Lei Xiao Bao , Liao Wen He , Dai Ning , Zhang Lin
Published: March 2010

To design the mechanical structure of a dental restoration system, which working parameter should be understand clearly in first, especially the grinding force, so, the experiment using the orthogonal method is employed to find out and analysis it. The orthogonal array and range analysis were employed to study the effect of the process parameter had on the grinding force when the dental CAM system is on working, all machining parameters used in the experimental process are referring to the technical requirements for dental restoration. A high accuracy machining center, a new dental bur used only for dentistry, and a zirconia block which have excellent properties for dental restoration, are been employed to conducted the experiment, made it’s results believable. The experimental results demonstrated that the depth of cut, be the major parameter on cutting force, followed by width of cut. According to the result of analysis, the stress situation of mechanical structure of the CAM dental restoration system can be established. At the last part of this paper, a model for predict the grinding force is developed based on the experiment by means of linear regression analysis, which can be used to estimate the values of grinding force given certain grinding parameters. All of these indicated the direction for design the structure of system.
Realization Technology of A New Virtual Environment for Large-Scale Complex Products Assembly
Authors: Yao Ying Xue , Lang Yue Dong , Xia Ping Jun , Chen Peng , Liu Guo Hua
Published: March 2010

To deal with the problems of complicated process, difficult operation and low efficiency for large-scale complex products assembly, a new immersive virtual environment (VE) with virtual reality (VR) technology is built in the process of assembly planning and training. The environment is composed of a free walk machine and spherical screen projection system. In this paper, a free walk machine with movement perception function is developed to achieve natural human-computer interaction. And an approach based on two viewpoints match is adopted to improve immersive effect of stereo projection in the projection system. On the basis of that, a geometry calibration method based on Bicubic NURBS(Non-Uniform Rational B-Spline) surface matching target-controlled dot-matrix is proposed to achieve non-distorted image on spherical screen. Finally, the environment is applied in the process of satellite assembly process planning, and the display result shows that the VE development is feasible and valuable.
Optimization Design Method of High Speed Milling Cutter Based on Axiomatic Design
Authors: Jiang Bin , Ming Jun Jian , Zhang Wei , Zheng Min Li
Published: March 2010

Using the theory of axiomatic design, the optimization method of high speed milling cutter was investigated, and the optimization designs of teeth distribution and dynamic balancing were created by means of function decomposition and grey cluster analysis. Results showed that the method solved effectively the problem of parameters interaction and functions coupling in optimization design of cutter, the effects of simplifying design process and improving collaborative design were validated in development of cutter. Experiments indicated that the vibration in high speed machining aluminum alloy was depressed, the cutter held higher cutting stability, and its cutting performance met the optimization design requirement of high speed milling cutter.
The Experiment Research of Precision Grinding of Li-Ti Ferrite with Graphite Grinding Wheel
Authors: Zhang Bei , Su Hong Hua , Xu Hong Jun , Fu Yu Can
Published: March 2010

Li-Ti ferrite used in aviation occasions needs good surface quality. In conventional grinding it is difficult to meet the surface demand. Accordingly, this paper proposed a new grinding process to change the situation. The process employed graphite grinding wheel which is always used in ultra-precision grinding of steel piece. The process can obtain good surface quality and ensure certain material removal rate. The ground surface appearance is nearly mirror-like. The lowest surface roughness of Ra value of the ground surface is 0.05μm in the experiment. The ground surface morphology is made up of spread glazed area and dispersed minute pits. The ductile regime dominates the material removal mechanism and no surface damage is induced in the process. In consideration of the results in the experiment it can be seen that grinding with graphite grinding wheel is a good finishing procedure in ferrite machining because of its obtained high surface quality.
Experimental Study on the Effect of Cold Air Cutting on Cutting Temperature, Cutting Force and Tool Wear during Machinging of Cr12 Tool Steel
Authors: Ren Jia Long , Su Y. , Guan X.Y. , Li Y.W. , Wang Q.X.
Published: March 2010

Cold air cutting is a kind of environmetnally friendly cutting technology. The present study investigated the influence of cold air and cold air with oil mist on cutting temperature, cutting force and tool wear in the machining of Cr12 tool steel. For comparision, dry and flood coolant was also used as the cooling/lubrication conditions in the experiments. The findings of the study show that cold air with oil mist was the most effective cooling/lubrication condition in reducing the cutting temperature, cutting force and tool wear during the machining of Cr12 tool steel.
Experimental and Simulation Study on Diamond Convex Surface Film
Authors: Li Duo Sheng , Zuo Dun Wen , Zhang Jian Yun , Lu Wen Zhang , Xu Feng , Zou Ai Hua , Cui Xia
Published: March 2010

Diamond convex surface films were synthesized on molybdenum substrate using DC plasma Jet CVD (DCPJCVD), and their microstructure and topography were characterized by those techniques such as X ray diffraction, Raman spectroscopy respectively. It showed that, when the substrate was pre-treated by polishing using successive micron diamond powder (about 30～3μm), diamond film was a polycrystalline texture and (111) faces were dominant. Raman spectrum shows that high quality diamond convex surface film was prepared successfully. Meantime, We used Finite element methods (FEM) to simulate the velocity, pressure and temperature fields of reaction chamber respectively, and it indicated that the distribution of the velocity, pressure fields were fluctuant, which had negative influence on diamond film, but the temperature fields is uniform, and it is an important factor to prepare high quality diamond convex surface film.
Research on the Architecture of Networked Process Integration System for Windows Manufacturing
Authors: Ze X.B. , Qu Y.B. , Zhang W. , Fu Y.
Published: March 2010

Enterprise dynamic alliance is an important enterprise mode for agile manufacturing which requires process integration system to provide many new characteristics to support the setup and operation of the enterprise dynamic alliance. Based on the analysis of production process characteristic for windows manufacture enterprises, a three-layer distributed structure thought of Browse / Server – based process integration system for windows industry is presented according to the function of process integration system., and the system architecture consisting of browser-client layer, application server layer, database server layer is constructed. At the same time, some requirements about design service and process service of process integration system for windows are presented. At last the realization method of the system is enucleated.
The Cutting Behavior of Diamond Coated Tool in Machining Al-20wt%Si Alloy
Authors: Lu Wen Zhuang , Zuo Dun Wen , Yang B. , Xu Feng , Wang M.
Published: March 2010

The performance of CVD diamond coated cemented carbide cutting tool in comparison with K10 uncoated cemented carbide tool in the dry turning of Al-20wt%Si aluminum-silicon hypereutectic alloy was investigated. The obtained results showed a better cutting performance for CVD diamond coated tool in machining Al-20wt%Si, particularly in terms of cutting force, tool wear, surface roughness, when compared with K10. The cutting forces are lower with CVD diamond coated tool and the depth of cut promotes a great increment of the cutting force. The tool wear processes taking place in the tool tips in all cutting conditions. The tool life of CVD diamond coated tool is longer than that of the uncoated K10. The surface roughness Ra increases obviously with the increase of feed rate using a CVD diamond coated cutting tool. A higher feed rate produces surface rougher. The chip morphology in machining of Al-20wt%Si alloy by CVD diamond coated tool is continuous. The tests showed that the CVD diamond coated tool can be applied on the K10 tool at low feed rate to produce high quality surfaces.
Chatter Stability Prediction in High Speed Milling Considering Multi-Degree of Freedom
Authors: Sun Shan Shan , Tang Wei Xiao , Xu Xi Qing
Published: March 2010

Chatter problems occurring during high speed milling affect the quality of the finished workpiece and, to a lesser extent, the tool life and the spindle life. Therefore, the prediction of stable milling regions is a critical requirement for high speed milling operations. In this paper, a dynamic model of a high speed spindle system considering the multi-mode dynamics is elaborated for the purposed of stability prediction. A stability lobes diagram (SLD) shows the boundary between chatter-free machining operations and unstable processes, in terms of axial depth of cut as a function of spindle speed. These diagrams are used to select chatter-free combinations of machining parameters. The proposed method enables a new stability lobes diagram to be established that takes into account the effect of spindle speed on multi-mode dynamic behavior.
Optimal Cutting Parameters for Precision Machining Process
Authors: Song Qing Hua , Tang Wei Xiao , Ai Xing , Wan Yi
Published: March 2010

Semi-discretization method is applied to construct stability chart and performance contour in the parametric space for milling processes. The method creates a mapping of the system responses in a finite dimensional state space. Based on the discipline of that, the smaller the largest absolute value (μmax) of the characteristic multipliers of the mapping is, the faster the system converges to zero, minimization of μmax leads to optimal stable limit. The optimal limits are obtained by using stability chart and performance contours. Additional, a novel analytical method for selection of optimal depth of cut (axial depth of cut) is presented. An example of 2-DOF down-milling model is employed to demonstrate the method. It is shown that the spindle speeds corresponding to the optimal depths of cut locate the left side of the resonant spindle speeds, and the optimal cutting parameters pair (spindle speed and depth of cut) can be used to offer high finishing accuracy in precision machining.
Study on the Friction and Wear Behavior of Grind-Hardened Layer
Authors: Zhang Jian Hua , Ge Pei Qi , Zhang Lei , Yu Yang , Li Hui
Published: March 2010

The grind-hardening technology utilizes the grinding heat to harden the surface of the workpiece. The friction and wear performance of the grind-hardened layer is one of the important parameters. In this paper, the friction and wear performance of the grind-hardened layer was studied by the friction and wear experiment. The wear rate and the friction coefficient of the grind-hardened steel were studied by comparing with conventional hardened steel and non-hardened steel. The surface worn morphology and the collected wear debris of the grind-hardened steel were observed during the experiment. The wear mechanism of the grind-hardened steel was analyzed under different friction conditions.
Effect of the Internal Stress of Polished Thick Diamond Film on the Infrared Transmittance at Different Temperature
Authors: Chen Rong Fa , Shen Zhao Xia , Dai Liang Gang , Zhang Xian Liang , Zhu Rui , Zuo Dun Wen
Published: March 2010

The optical-grade diamond film was prepared by DC plasma jet CVD method, and a double-sided polishing was made by EDM and mechanical polishing technology. The investigations of the internal stress at different temperature on the infrared transmission were tested in detail. SEM and AFM were used to study the polished surface morphology, surface roughness was 0.12nm and 0.25nm. XRD and Raman were characterized on the diamond films, the results showed a higher intrinsic quality. The internal stress distribution and infrared transmittance were investigated at 25°C and 100°C temperature respectively. The infrared transmission mechanism of diamond film was also discussed. The main reason of decreasing of infrared transmittance was the increasing grain collisions, which caused more scattering and absorption of incident light with temperature increasing.
Study on Working Hardening for AISI-1020 and AISI-1045 Steel Fine-Blanking with Negative Clearance
Authors: Li J.H. , Fan Wei Fu , Zhang Zhong Mei
Published: March 2010

This paper carries through pure shearing fine-blanking processing experiment with negative clearance for the AISI-1020、AISI-1045 steel and the relations curves of the blanking force and the blanking stroke is obtained. The micro hardness of the sheared surface for the blanked work pieces in breadthways and lengthways direction is measured by Vickers-micro hardness instrument (MH-6), thereby the relations curves of punch stroke and the micro-hardness of the blanking work pieces are gained. The relation between work hardening degree and blanking clearance for the negative blanking is obtained too. This paper focuses on formation mechanism of work hardening for the negative blanking and analyzes the work hardening capability of blanked work piece. The work hardening degree is compared to the materials which possess different hardening index. The research shows that the work hardening degree of the blanking work pieces is strengthened evidently by the fine-blanking with negative clearance and the hardening layer of blanking fracture could enhance structure intensity and wear resistance of blanking work piece evidently. Therefore, it could enhance fatigue strength exceedingly and extend the working life of work piece greatly.
Investigation of Water Vapor as Green Coolant and Lubricant in Turning of Austenitic Stainless Steel
Authors: Zhang Yue , Han Rong Di , Tang Yan Li , Wang Yang
Published: March 2010

It is examined that the effects of water vapor as green coolant and lubricant on the cutting of austenitic stainless steel. Compared to nitrogen, oxygen, argon and carbon dioxide gas applied and dry cutting, water vapor produced the lowest cutting force and deformation coefficients, improved the machined surface appearance and helped to chip forming and breaking. And the lubricating actions of water vapor and gases may have the relation with the molecule polarity and the capacity of adsorption in the cutting zone. All these gases and water vapor have the green characteristic without pollutions. Comparably, water vapor may be a good selection for the green machining of austenitic stainless steel.
FEM of Saw Tooth Chip Formation under Different Cutting Edge
Authors: Yue Cai Xu , Liu Xian Li , Zhai Yuan Sheng , Ji Sheng Yuan , Zhao Xing Fa
Published: March 2010

The generation procedure of saw tooth chip when PCBN tools orthogonal cutting hard steel GCr15 is emulated by FEM software ABAQUS in this study. The model effectively overcomes serious element distortions and cell singularity in high strain domain caused by large material deformation. The effects of cutting edge preparation on cutting force, cutting temperature and residual stress are analyzed. Results of FEM show that cutting edge preparation has a great impact on cutting procedure. Under the same cutting condition, cutting force, temperature and residual stress of sharp edge, honed edge and chamfered edge increases in turn, and three kinds of cutting edge have the same change rule in residual stress. Chamfered edge has a good temperature distributing, and it is the best edge preparation in hard cutting.
Structure Characteristic Analysis and Optimization Design for Microsatellite
Authors: Zheng Kan , Liao Wen He , Zhang Xiang
Published: March 2010

According to the structural layout and mechanics characteristic of microsatellite, the FEM was established reasonably. Base on the FEM analysis and its characteristics, the structure of microsatellite was optimization designed. In the optimization process, the optimization model was established with the design variables of aluminum panel thickness, core plate thickness and skeleton thickness, and subjected to stiffness, strength, displacement and size constraints. Then, used the sequential quadratic programming method for optimization analysis. The results of the optimization demonstrates that the weight of structure loss significantly, and the whole structure weight of the microsatellite loss 11%.Meanwhile, the iterative times of the optimization process is few, so it is very Meaningful and useful for actual project application.
Study on Forming Characteristics of Metal Sheet by Laser Shock in Oblique Angle
Authors: Jiang Yin Fang , Wang Fei , Zhu Yuan You , Gu Yong Yu , Lai Yan Ling
Published: March 2010

Laser shock forming in oblique angle of metal sheet is involved due to the complexity of parts profile and multiple points forming by laser shock. The influence of incident laser angle and constraint pore diameter of the mold on the forming characteristics of metal sheet is investigated according to the experiment and finite element simulation. The results show there is a horizontal deviating deformation in the place of the maximum deformation in oblique shock, as the incident angle deviating vertical direction increases, the vertical displacement amount decreases nonlinearly and the horizontal deviating amount increases gradually; and the vertical displacement amount of sheet increases with the increase of the mold constraint pore diameter in a certain range, but decreases above this certain range. The metal sheet fractures when shock times increase, the extended crack is paralleled to roll direction of metal sheet in vertical angle shocking, but the extended cracks in oblique shocking, some is paralleled to roll direction of metal sheet, another is vertical to this direction. The forming characteristics of metal sheet under laser shocking in oblique angle is very important, which provides evidence for the large area precision forming and parameters optimization by laser shock forming.
Research on Particle Characteristics of Cellulosine Used in Generation Basing on Two-Phase Flow of the Gas and Solid
Authors: Yang Lan Yu , Ma Yan
Published: March 2010

The amount of remainder in wooden biomass resources available which was used for power generation in China was surveyed. Technique feasibility of the wooden remainder used in power generation was analyzed. A super fine cellulosine disintegrator for power generation was designed, which combined both characteristics of the wooden biomass and particle size of the cellulosine for power generation. The cellulosine particles which were obtained were put emphasis on analyzing and all kinds of stressed conditions were obtained during process of the grading under the environment for two-phase flow of the gas and solid. One kind of grading model of the cellulosine particles for power generation was established in view of all kinds of the influence factors comprehensively. One kind of calculation method for grading particle-diameter of the cellulosine particle, and the experiment results showed that this method was feasible.
An Adaptive Random-Period Interpolator for Stepping Motor Systems
Authors: He Jun , You You Peng , Chen Hao , Wang Hua Ming
Published: March 2010

In motion control systems driven by stepping motors, reference word interpolation is usually used with a constant period, which inevitably results in vibration caused by quantization errors and interpolation spare. An interpolator with adaptive random-period is proposed: with the adaptive random-period interpolator, the high-frequency energy excitation from stepping motor driving signals can be greatly dispersed and the desired trajectory and feed profile can be realized through the mutual restriction between the velocity and the displacement. Simulation results show that the adaptive random-period interpolator can effectively improve the velocity excitation, resonant excitation and motion accuracy.
Experimental Research of YAG Laser Cutting Soda-Lime Glass Sheets with Controlled Fracture
Authors: Cai N. , Yang Li Jun , Wang Yang , Tian Zhong Guo
Published: March 2010

This paper indicates the experiments of YAG laser cutting soda-lime glass with controlled fracture. The qualities of glass obtained by laser cutting and mechanical cutting are compared. The impact of laser power, scanning speed and spot size on the cutting quality is studied and the optimum laser parameters are given. Finally the experiments of laser cutting two-layer glasses, glass tube and laser cutting in curve paths are carried out. The results show that good cutting quality of glass can be acquired by YAG laser cutting.
Simulation of the Temperature Distribution on Interior Hole Surfaces of Drawing Dies in HFCVD Reaction
Authors: Zheng Hua , Sun Fang Hong
Published: March 2010

The temperature distribution on interior hole surfaces of drawing dies in HFCVD reaction was analyzed by combining the FEM simulation and related measurements. The analysis showed a parabolic tendency of elevating substrate temperatures and a moderating tendency of corresponding temperature gradients while enlarging hot-filament radius. The optimization of the hot-filament radius for a sized drawing die to achieve a comfortable substrate temperature distribution for depositing superior diamond films was conducted and safely supported by related experiments. SEM was used to observe the morphology of diamond films. The simulation is of practical significance for improving the deposition of diamond films in HFCVD reaction.
Study on Milling Dynamics of the Thin-Webbed Structure Component
Authors: Wu Kai , He Ning
Published: March 2010

The existent studies on the machining technologies of the thin-webbed structure component were reviewed. Then the milling dynamics analysis model on the thin-webbed component was presented. Based on the model, FEM analyses on the machining dynamics of the thin-webbed structure component were carried out. At last, the analysis results were concluded. It is shown that there is an optimized rotation speed of the spindle to minimize the machining vibration.
Optimization of Milling Parameter Based on Modified Genetic Algorithm
Authors: Zhang Jing Ying , Pang Si Qin , Yu Qi Xun
Published: March 2010

This article establishes the multi-target optimization model of numerically-controlled milling parameter and illustrates the optimization design and system realization through modified Genetic Algorithm (GA). This system adopts double-breakpoint crossing and self-adaptive mutation and inverse operator through transgenic technology. It improves its local searching ability and calculation speed.
Machinability Evaluation of the Finish Hard Turning α+β Titanium Alloys
Authors: Ming Wei Wei , Chen Ming , Rong Bin , Han Bing
Published: March 2010

The two phase (α+β) titanium alloys are extensively applied in aerospace, automotive, and biomedical industries owing to their excellent comprehensive performance combining of high strength-to-density ratio, good corrosion resistance, and high strength at elevated temperature. However, the poor machinability of these alloys restricts the improvement of manufacturing productivity and cost savings. In this paper, machinability of three α+β titanium alloys was studied at the finish hard turning conditions.