bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Flow Path Feature Based Hydraulic Manifold Block Design
Authors: Gao Wei Guo , Niu Wen Tie , Zhang Da Wei
Published: August 2009

The modelling method of dynamic flow path feature (DFPF) is proposed for the design process of hydraulic manifold block (HMB). In this method, temporary body model and B-Rep model are adopted to represent geometric model of DFPF; the former is used for showing flow path, checking connectivity and safe wall thickness, and the latter is used for saving the final results. A novel feature topological representation method based on solid adjacency graph (SAG) is provided, and then validity of feature semantics can be checked through SAG. Finally dynamic topological changeability of flow path feature is realized by constraint solution and knowledge driving. Object-oriented model of DFPF is given, and the design process of HMB based on DFPF is illustrated.
Study of Fluid-Solid Simulation on the Large-Scale Hydrostatic Bearing of Hollow Coaxial
Authors: Yu Xiang Jun , Wang Ji Xin , Li Yong
Published: August 2009

In order to investigate the changing law of the film thickness caused by the deformation of hollow coaxial and drum-shaped lining and accurately calculate the stress of hollow coaxial and rum-shaped lining, the fluid-solid numerical simulatied model of a large-scale hydrostatic bearing was established. The stress and deformation of hollow coaxial and drum-shaped lining was obtained by indirect coupled methods. The typical impact factors and the deformation laws of the thinnest film were discussed. The simulation results indicate that the maximum stress locatioes on the drum-shaped lining and hollow coaxial; and the deformation of the hollow coaxial is 60.47 times that of the drum-shaped lining, and the oil film thinnest thickness decreases by 12.1% due to the deformation of the hollow coaxial and drum-shaped lining; and the stiffness of the hollow coaxial makes greatest impact on oil film deformation.
Simulation Study of Temperature Field and Stress Field of Disc Brake Based on Direct Coupling Method
Authors: Yang Xun , Wang Ji Xin , Fan J.C.
Published: August 2009

In the process of automobile braking, the interaction between the temperature and the dynamic stress of disc brake is a very complex work. In order to simulate this problem accurately, a three-dimensional finite element model was built. Meanwhile the displacement and thermal boundary conditions for solution were determined, in which the coefficient of convection varies with the transient changing of temperature and time. The distributions of stress field and temperature field of the rotor and pads in an emergency braking were analyzed by the direct coupling method. The results of analysis prove that the thermal-structural direct coupling method can simulate the interaction between the stress field and the temperature field more exactly than the axisymmetric method and sequential coupling method do. The changing of stress field is mainly influenced by the temperature field. The results extracted from coupled simulation can give references for the material selection and structural designs in the development of disc brake.
A Fast Reconstruction of Dense Unorganized Point Cloud Based on 3-Color Octree
Authors: Zhou H.M. , Liu Z.G. , Li M.X. , Lu B.H.
Published: August 2009

This paper describes a fast reconstruction algorithm of implicit model based on 3-color octree structure for dense unorganized point cloud. At first, the point cloud is stored with an extended octree, 3-color octree. Aiming at this 3-color octree structure a new node watershed algorithm is presented with a higher efficiency to estimate the signs of subdivided leaf nodes. So the leaf nodes are divided into three types: interior, boundary and exterior nodes. To quickly reconstruct the model we sample the 3-color octree structure only at boundary nodes, which greatly reduces the number of sampled points. Then, the triangular meshes are extracted according to the relationships of boundary node. Finally the applications are illustrated in several point clouds, which shows the efficiency and precision of this reconstruction algorithm.
Rack and Pinion Lifting Device Structural Design of Large-Scale Dynamic Sculpture
Authors: Lv C.Y. , Shi W.W. , Yang Xian Hai
Published: August 2009

The design of lifting device for a large-scale dynamic sculpture at tourist district was introduced. According to its own characteristics of lift device, the "back-to-back" style of rack and pinion for the lift system was designed. It was used the finite element analysis software to analyze the strength of the rack and pinion which is a key part of the lift device. According to the stress of dedendum for the pinion is too bad, it was proposed that increased the radius of the fillet for dedendum.
Study on Drive Characteristic of Multi–Rope Friction Winder Using Functional Virtual Prototyping
Authors: Liu Yi , Chen Guo Ding , Li J.S. , Xue Y.J.
Published: August 2009

The main objective of this study was to model and simulate a reduced three-dimensional (3D) model for researching the hoisting system of a Multi – rope Friction Winder. By introducing the relative nodal method, the simplified dynamic equations have been derived via the virtual work principle and validated on a virtual prototype with the RecurDyn software package. Kinematics and dynamics characteristic date are obtained by computer-aided dynamic simulation of virtual Multi – rope friction winder. The result is in accord with theoretical analysis. The research work will provide a powerful tool and useful method for the design of economic and credible elevator system. The approach can be generalized to analysis other flexible drive fields.
Development of a Multidisciplinary Collaborative Design System
Authors: Chen Liang
Published: August 2009

A new product modeling method for product multidisciplinary collaborative design (MCD) is put forward. The method uses a flexible product model which can be extended transversely and lengthwise by multiple levels’ inheritance and new attribute classes’ addition and a class inheritance mechanism under network environment which allows each discipline to build own view model of a product. An open and flexible system architecture supporting the product MCD effectively is put forward, and prototype system implementation is introduced.
Cost Estimation Model for Few Samples and Information in Product Early Design Stage
Authors: Jiang Shao Fei , Lu Cong Da
Published: August 2009

Product cost estimation in early design stage puzzles researchers for long-time. A new product cost estimation model is proposed, which is applicable for few estimating samples and product information in early design stage. Similarity between the estimating product and the samples are calculated by model of Euclidean distance. Both of utilization ratio of estimating samples and reliability of estimation result are improved based on samples’ sequencing for effect of product cost. The cost estimation model is applied in design of claw of brake disc. The estimation result indicates that the presented model can be used for condition of few estimating samples and product information in early design phase.
Study on the Magnetic Abrasive Finishing Based on 5-DOF Machine Tool
Authors: Xu L.J.
Published: August 2009

Magnetic abrasive finishing (MAF) is one of the advanced finishing processes, which produces a high level of surface quality. The technology is researched and applied just in recent years and it has good effect at the complex surface product manufacturing due to its flexibility and self-adaptability. Based on research about the theory and characteristic of magnetic abrasive finishing and 5-DOF Machine Tool, this study set up the interpolation mathematic model and space-line interpolations and circular arc interpolations of the tool-path for magnetic abrasive finishing were researched.
Three-Dimensional Complex Groove Reconstruction of Cutting Tools Using Multidisciplinary Design Optimization Method
Authors: Tan Guang Yu , Liu Guang Jun , Li Guan Hui
Published: August 2009

In the design and optimization of cutting tool’s groove, it is necessary to comprehensively consider the multidisciplinary coupling effects of stress field, temperature field and working environment, and balance the coupling effects on the cutting performance. The multidisciplinary optimization method is employed to study the 3D complex groove reconstruction of cutting tools in this paper. The two-level reconstruction approach is proposed. The groove reconstruction of waved-edge insert is presented as a numerical example, and an optimal design of the groove is obtained. The optimization results show that the reconstructed tool has a satisfied performance on the stress field and temperature field.
On Reconfigurable Machines and Reconfigurable Assembling Machine for DC Connector Plug
Authors: Zhang Zi Qiang , Liu Z.H.
Published: August 2009

Reconfigurable machines are essential components to implement a reconfigurable manufacturing system. This paper focuses on one of reconfigurable machines: reconfigurable assembling machine. A reconfigurable automatic assembling machine for DC connector plug is designed. It can be divided into the basal module and the changeable module. The same basal module with different changeable module can be assembled into different special assembling machines for DC connector plug with different shape, size or number of electrodes.
Dynamical Simulation Analysis and Experimental Study on a New Sugarcane Cutting Device
Authors: Lai Xiao , Li Shang Ping , Liang S. , Ma F.L. , Cheng Z.Q. , Dai X.B.
Published: August 2009

The cutting stiffness has notable influence on the sugarcane cutting quality, so great importance should be laid on enhancing the cutting stiffness when designing the cutting device. Based on cutting mechanism analysis, this paper proposes a new design of cutting device to increase the cutting stiffness by properly adding an auxiliary support bar and builds up 3D model of it. Then combining of virtual simulation analysis and physical experiment, it compares and analyzes the different stiffness and cutting quality with support bar in various support position or without it. The result shows that the new design with properly mounted support bar can raise 15.30% of the cutting stiffness, and consequently improve the sugarcane cutting quality distinctly.
A MEMS Capacitive Gyroscope with Improved Reliability
Authors: Liang Xin Jian , Gao S.Q.
Published: August 2009

The MEMS capacitive gyroscope has wide application foreground, the reliability of MEMS gyroscope is a key problem for its commercial application. With the development of the MEMS gyroscope industrialization, the reliability is underway to meet the need of market. In this paper, the adhesion failure modes of the MEMS gyroscope were presented. In addition, the adhesion failure analysis was illustrated. Finally, a lateral comb structure to improve the reliability of the MEMS gyroscope was presented. Test result indicates that the reliability of the MEMS capacitive gyroscope is improved.
Robust Optimization of an Accelerometer Considering Fabrication Errors
Authors: Liu Guang Jun , Jiang Tao , Wang An Lin
Published: August 2009

A robust optimization approach of an accelerometer is presented to minimize the effect of variations from micro fabrication. The sensitivity analysis technology is employed to reduce design space and to find the key parameters that have greatest influence on the accelerometer. And then, the constraint conditions and objective functions for robust optimization and the corresponding mathematical model are presented. The optimization problem is solved by the Multiple-island Genetic Algorithm and the results show that an accelerometer with better performance is obtained.
Development and Experimental Investigation of Micro-Turbine in Millimeter Size
Authors: Liao Z.B. , Zhang L. , Xu Z.J. , Su H. , Fu Q.
Published: August 2009

The current research about Power-MEMS is mentioned. A micro turbine-generator system which aims to generate ultra-high power density at a high speed about 105r/min is put forward. Its work-principle is adequately introduced. The performance-tests of the turbine-generator are accomplished on a test-bench which has been specially designed. It can be seen that the micro turbine-generator system is able to generate about 0.6W output-power and a maximal voltage about 12.5V. Moreover, the turbine-generator is tested in four conditions in order to investigate how the pressure, volume flow and temperature of inlet gas affect the system’s performance.
Investigation of 2-DOF Precision Positioning System for IC Packaging
Authors: Feng Xiao Mei , Zhang Da Wei , Li L.S. , Liu W.K.
Published: August 2009

A new 2-DOF positioning table of high speed and accuracy, directly driven by voice coil actuator, is put forward, which can be applied to IC packaging for wafer wire bonding equipment. With the help of a novel elastic decoupling mechanism, the driving element is mounted on the baseboard, diminishing its moving inertia, improving its dynamic performance. By establishing dynamic model of VCA and positioning table, an electromechanical coupling control system based on displacement PID controller is proposed. The prototype experiment shows that the new 2-DOF positioning system is of higher speed and higher accuracy than the traditional ones.
Rectangle Piezoelectric Bimorph Bone Conduction Auditory Device
Authors: Sun Jing Yang , Cheng G.M. , Wu B.D. , Ma Ji Jie
Published: August 2009

The piezoelectric bone conduction auditory device (PBCAD) with a rectangular piezoelectric bimorph as a driving components was designed based on the principle of bone conduction(BC), the audio signal converted to a vibration signal stimulate the auditory nerve via the skull to create hearing. Finite element analysis of rectangular piezoelectric vibrator means to support and optimize the structure of the program and improve equipment sound effects in the regional auditory signals of low-frequency, the experiment of rectangular PBCAD chalks up the curve of structure parameters. Experimental studies show: rectangular piezoelectric BC unit can achieve better function of bone conduction auditory device (BCAD).
Effect of Machining Parameters on Microstructure and Hardness of Ultra-Fine Grained Material Created by Large Strain Machining
Authors: Wu Chun Ling , Ye Bang Yan , Deng Wen Jun
Published: August 2009

Effect of plane strain machining parameters such as rake angle and cutting velocity on the formation of ultra-fine structure in several materials has been studied. The microstructure and hardness of chips generated by machining were characterized by optical microscopy, scan electron microscopy and hardness tester respectively. The experimental results indicated that chip materials with ultra-fine grained and high hardness can be produced with more negative tool rake angle at some lower cutting velocity. The rake angle has more important effect on the formation of ultra-fine grain chips than cutting velocity. The rake angle for getting chips of obvious refined and significant hardened is different for different materials respectively. While the temperature of shear plane and tool-chip interface are increased with the increasing cutting velocity which alleviates the increase of hardness produced by decreasing rake angle.
Measurement for the Microchannel Width of Injection Molded Micro-Fluidic Chips by Digital Image Processing of Micro Flat Photos
Authors: Zhu T.L. , Zhou Liang , Yan Wei
Published: August 2009

Micro injection molding is competitive for fabrication of polymer-based micro-fluidic chips because of its high productivity. Unlike hot embossing, injection molding will not provide even molding condition for everywhere of the molded part. So the microchannels of an injection molded micro-fluidic chip need to be checked everyplace, while a hot embossed micro-fluidic chip can be checked only by one slice of the microchannels if only the micro protrusions of the mold stamp remain the same cross-sectional figure. Because an injection molded micro-fluidic chip has characteristics that its replication of the micro stamp protrusion is perfect in height but not satisfactory in width, especially for the width of the micro protrusion’s root which matches the molded microchannel’s opening, in this study micro flat photos of injection molded micro-fluidic chips were processed by our own image processing system developed from the image box of Matlab software. Measuring data about microchannels width from the micro flat photos were compared with measuring data obtained from a cross-sectional photo of one slice of the microchannels. Difference between data of these two measuring ways was less than 2% for opening width of the molded microchannel. So by image processing of the micro flat photos, rapid overall non-destructive testing of micro replication can be carried out for injection molded micro-fluidic chips.
Research on Micro Electrochemical Machining Based on Multifunction Machine Tool
Authors: Li Xiao Hai , Zhao Li Jie , Wang Xin Rong , Zhang X. , Wang Zhen Long
Published: August 2009

The research aims to develop an experimental equipment to carry out in depth research on micro electrochemical machining (micro-ECM). The mechanisms of ultra-short pulse current micro ECM are discussed. As a consequence, lower machining voltage, lower passivity electrolyte concentration, high frequency short pulse power supply and micro rotating tool electrode at high speed have been synthetically used to localize the dissolution area during micro-ECM. The machining gap can be kept at a very small value, and the better resolution of machined shape is achieved by using a novel designed electrode gap control system and the effective utilization of ECM for micromachining is fulfilled. The experiments on microstructure by micro-ECM milling on stainless steel plate are conducted. The micro structures milled on 304 stainless steel foil with 300μm thickness with high precision and high aspect ratio are achieved, and the width of micro beam is about 60μm.
Formation of PZT Thick Film Single Elements Using EHDA Deposition
Authors: Wang Da Zhi , Dorey R.A.
Published: August 2009

In this paper, electrohydrodynamic atomization combined with a polymeric micromoulding technique was used to form PZT single element devices using a PZT sol-gel slurry without an etching process. The PZT single element device was initially designed to work as a piezoelectric ultrasonic transducer consisting of a circular or a square of various sizes, which was produced and used to evaluate the process. The resulting PZT device had a homogenous microstructure. It was observed that the relative permittivity of the circular and square single element devices was especially high at small size due to the fringe effect. The results show that the radius and width of the PZT single circular and square element devices with a thickness of 15µm should be bigger than 400µm in order to reduce the fringe effect.
Study on Replication of Densely Patterned, High-Depth Channels on a Polymer Substrate Using Hot Embossing Techniques
Authors: Sun Huan Li , Liu Chong , Li M.M. , Liang Jun Sheng , Chen H.H.
Published: August 2009

Micro hot embossing process is a cost-effective method for parallel replication of polymer microstructures. To study the effect of hot embossing and demoulding parameters on the replication accuracy of the polymer microstructure, densely patterned and high-depth channels on 50mm×50mm polymer substrates were fabricated by hot embossing in this paper. Experimental results showed that the replication accuracy of the microstructure increased with the increasing of hot embossing temperature and the thickness of polymer substrates. It can be found that demoulding became more difficult when replication accuracy increased. The reason was that higher replication accuracy resulted in larger contact area between the replica and the embossing mold. The demoulding problem could be solved by rising demoulding temperature. However, overhigh demouding temperature (110°C) would lead to round corners at the edges of the ribs. Experimental results also showed that very small channel widths and depths errors (less than 1.2%) of the microstructures with 2mm thickness substrates could be achieved, when embossing and demoulding temperatures were set to 120°C and 100°C, respectively.
A Silicon Micro Direct Methanol Fuel Cell Demonstrator Using Microfabrication Techniques
Authors: Liang Jun Sheng , Liu Chong , Sun Ling Jun
Published: August 2009

. This paper presents the design, microfabrication and characterizations of a silicon based, single-cell μDMFC demonstrator for micro/portable electrical power applications. The flow field plates of the fuel cell were made on 2“silicon wafers utilizing wet-etching and sputtering techniques. The fuel cell was assembled in an epoxy-based packaging process. Results show that a lower internal ohmic resistance of the fuel cell can be achieved with a thicker current collecting layer (CCL). Influence of the operating conditions on the μDMFC performance was also investigated. It was found that 2M methanol can yield a better fuel cell performance because it provided a better compromise between the methanol crossover and mass transportation during operation. On the other hand, a 4-time increase of the peak power density of the fuel cell was achieved by increasing the methanol temperature from 20°C to 80°C.
Experimental Study on the Rheological Characteristics of Polymer Melts under Micro Scale Effect
Authors: Zhao D.Y. , Jin Y.F. , Wang Min Jie , Sun X.W. , Song M.C.
Published: August 2009

The rheological characteristics of four polymer melts (PS, PMMA, PP and HDPE) are investigated by a capillary rheometer with the die diameters from 1.5mm to 0.5mm.The effects of temperature on shear viscosity and the effects of both temperature and shear rate on non-Newton exponent of melts are discussed when the die diameter is 0.5mm. The results show that the shear viscosity of four polymers decreases with the rise of shear rate. The shear viscosity of PS and PMMA increases with the decrease of die diameter, the shear viscosity of PP and HDPE decreases with die diameter and minute differences of shear viscosity with different die diameters are observed with the growth of shear rate. When the die diameter is 0.5mm, Arrhenius equation is found to be suitable to describe the relations between shear viscosity and temperature for four polymer melts. The non-Newton exponents of four polymer melts increase with the temperature and decrease with the rise of shear rate.
The Research and Implementation into Knowledge Reuse System of Product Design of Printing Press
Authors: Qi Yuan Sheng , Ding Yu Feng , Wang X.H. , Li J.J. , Zhang B.
Published: August 2009

Aiming at the reuse of design knowledge, this paper proposes knowledge reuse technology for product design of printing press which is based on rule and case. An integrated software package with SQL Server which is Database Management System (DBMS) and VisualC++6.0 which is a kind of development tools has been developed. This software may be embedded in the environment of Solidworks to assist the designer to index correlative design knowledge and develop new product of printing press after modification.
Modelling and Fabrication of 3-D Carbon-MEMS for Dielectrophoretic Manipulation of Micro/Nanoparticles in Fluids
Authors: Tang Zi Rong , Malik M.Rizwan , Shi Tie Lin , Gong J. , Nie L. , Liao Guang Lan
Published: August 2009

Carbon-MEMS (C-MEMS) have emerged as a new category of devices for micro/nano technology with many potential applications. Dielectrophoretic manipulation of micro/nanoparticles with C-MEMS is studied in this paper. Through electric field distribution modeling in carbon electrode array, we analyze the strongest simulation effect results of electric field in three dimensional (3-D) surface plots depicting the magnitude of electric field in various cross sections at different heights above the channel floor for 2, 10, 30 and 50 μm high carbon electrodes. It is represented here that maximum intensity of electric field generates with the equality between the height above the channel floor and the height of the electrodes. Simulation parameters involved are for dielectrophoretic manipulation of micro/nano particles based on 3-D C-MEMS. The advantages of using 3-D C-MEMS electrodes over other techniques of creating high-throughput systems for dielectrophoretic manipulation environment surrounded by micro/nano horizons are: (i) complex microscale 3-D electrodes with high-aspect ratios can easily be shaped and patterned using conventional lithography (ii) carbon has a high window of stability thus allowing application of higher voltages (iii) there is no need for bulk micromachining or patterning electrodes on multiple planes (iv) the distance between electrodes can precisely be controlled through the lithography process. FEMLAB 3.4 Multiphysics Modeling software (COMSOL, Stockholm, Sweden) is used for the modeling of electric fields and one-layer C-MEMS microelectrode array was fabricated with SU-8 photoresist.
The Dimension Accuracy Analysis of a Vacuum Forming Mold for IC Packing Bag
Authors: Lin Wei Shin , Lin Jui Chang , Lee Jeng Nan
Published: August 2009

This article is pointed to the dimension accuracy analysis of the vacuum forming mold for plastic carrier tape. The dimension accuracy of the vacuum forming mold was decided by the dimension specification of the plastic carrier tape. After detail design of the parts which would be manufactured and assembled. The accuracy and performance of the mold had been tested subsequently. The dimension accuracy of the mold was conducted by the accuracy of the plastic carrier tape. Variation of dimensional accuracy of the plastic carrier tape was inspected to evaluate the performance of the vacuum forming mold. Mean and variance test was conducted under the significance level of α = 0.05.Through series of inspections, all the plastic carrier tape met the specification of dimension accuracy which indicated that the precision and performance of the developed vacuum forming mold also met the requirement.
The Depositional Laser Cladding with Fiber Laser
Authors: Lv Peng Fei , Chen Ji Min , Liu F.R.
Published: August 2009

Laser cladding has been developed as a useful technology to modify material surface in industry. In this paper a new approach of surface modification is introduced. Depositional Laser Cladding (DLC) was developed and the different mechanisms were investigated during the manufacture. Basing on particular analysis of defects in the experiment, the relation between the quality of cladding layer and laser energy density is manifested. Depositional effect and thermal effect play their roles in different place and the depositional effect provides thin layers with the thickness of near mean particle size. Appropriate parameters of laser energy can promote high quality, avoiding pores and stacks in agglomeration and ebullition. Controllable low thickness near mean particle size and sharp edge make it possible to be used on producing certain shape in the surface engineering field, such as restoring and gradient materials.
Research Progress on Multi-Scale Coupling Simulation of Ceramic Tool Materials
Authors: Cheng Hong Mei , Huang Chuan Zhen , Fang Bin , Liu Han Lian , Zhou Ting Ting
Published: August 2009

The simulation methods and application of different scales such as macroscopic, microscopic and nanoscopic in material design are primarily introduced. The essentiality of multi-scale coupling simulation of ceramic tool materials is analyzed. The research status of multi-scale coupling simulation of ceramic tool materials is also surveyed.
Preparation and Characterization of WC Matrix Nanocomposite Cermet
Authors: Yang Fa Zhan , Ai Xing , Zhao Jun
Published: August 2009

A new WC matrix nanocomposite cermet was prepared by hot-press sintering. In the composite, certain amounts of VC is added to the composite as grain growth inhibitors. The consolidation is carried out under pressure 30～35Mpa and sintering temperature 1610°C for soaking 30min sintering. Microstructure of the nanocomposite cermet is scanned by SEM and mechanical properties are measured. It is detected that microstructure and fracture morphology is dissimilar to different particle sizes. Experimental results show that particle size of WC is important to the composite. Results show that relative density and hardness have the similar trend in growth. Meanwhile, the function of Al2O3 addition is also investigated in this paper.
Preparation of an Advanced Al2O3 Based Nanocomposite Ceramic Die Material
Authors: Xu Chong Hai , Yi M.D. , Jiang Z.Y. , Zhang J.J. , Xiao G.C.
Published: August 2009

Through the incorporation of nano sized Titanium Carbonitride powders into the Al2O3 matrix, an advanced Al2O3/Ti(C7N3) nanocomposite ceramic die material was fabricated by vacuum hot pressing technique. Effects of the content of nano Ti(C7N3) on the microstructure and mechanical properties of the nanocomposite ceramic die material were investigated. It indicates that both flexural strength and fracture toughness were increased noticeably compared with the pure micrometer sized alumina ceramic. Toughening mechanisms of the ceramic composite were also analyzed. It reveals that the intragranular/intergranular microstructures and the resulted transgranular/intergranular fracture modes are the main causes for the reinforcing and toughening of the nanocomposite ceramic die material.
Effect of Ti3SiC2 Content on the Property of a Warm Compacted Cu-Ti3SiC2 Composite
Authors: Zheng Jun Jun , Ngai Tungwai Leo , Hu Chang Xu , Pan G.R. , Li Yuan Yuan
Published: August 2009

A simple and economical powder metallurgy forming process known as warm compaction was employed to fabricate a Cu-Ti3SiC2 particulate reinforced copper matrix composite for electro-friction purpose. Copper matrix composites reinforced with 5, 10, 15 mass% Cu coated Ti3SiC2 particulate were prepared by compacting the powder mixture with a pressure of 700 MPa at 145°C, and then sintered at 1000°C under cracked ammonia atmosphere for 60 minutes. Their density, hardness, tensile strength, elongation and electrical resistivity were studied. Result showed that within a reasonable limit, the addition of Ti3SiC2 particulate can increase the hardness of the composite without losing much of electrical conductivity. Sintered composite with 5 mass% Ti3SiC2 has an ultimate tensile strength of 182 MPa with an elongation of 10%, a hardness of HB 68 and a resistivity of 8.0×10-8Ωm. Compared with the samples using uncoated Ti3SiC2 particulate, the resistivity of the samples prepared by using the Cu coated Ti3SiC2 particulate have a better conductivity, but have a slightly lower mechanical property.
Microstructure and Mechanical Properties of Al Alloys by Semi-Solid Processing with LSPSF Technology
Authors: Guo Hong Min , Yang Xiang Jie , Wang J.X.
Published: August 2009

Rheoforming is becoming the choice of the casting industry which relies on the semi-solid slurry for high integrity structural parts. The potential of rheoforming with LSPSF (Low superheat pouring with a shear field) for aluminum alloys was investigated in the present work. High quality semi-solid slurries of a series of aluminum alloys were manufactured by LSPSF process, such as casting alloy A356, high strength alloy 201, secondary die casting alloy A380 and wrought alloy 2024, 6082 and 7075, in which the primary α-Al presented spherical, small and homogeneous distribution, especially with zero-entrapped liquid. Applications of LSPSF in high pressure die casting process and squeeze casting process were presented. Results showed that LSPSF rheoforming could improve microstructures and increase mechanical properties.
The Study of Flowing Balance with Multi-Cavity Die and Non-Uniform Thickness
Authors: Lin Jui Chang , Lee King Sun
Published: August 2009

This study aimed to create a multi-cavity and non-uniform thickness die casting for flowing balance. The die casting processes involved a hot-chamber die casting experiment and computer aided simulation to explore the flowing condition of the molten metal in the metal molding process. Computer-aided mould flow analysis software FLOW 3D V9.2 was applied to simulate the filling stage of zinc alloy in the mould cavities. The design parameters of the mould included four variables relating to the gate: width, position, shape, and thickness of cross-section.
Analysis results shows that the primary goals of balance design include two things: (1) the flowing path of molten metal was shortest; (2) the mould cavity was easiest to fill with molten metal. The flowing balance design used analysis software to simulate the flowing condition of the air, which produced an air trap. The melting metal motive force pushed air into the slug well in order to reduce the production of pores. The experiment confirms the actual flowing situation of zinc alloy with a nearly 95% accuracy.
Few Sampling Study on Whole-Life Design of Complex Electro-Mechanical System
Authors: Zhang B. , Chen Jun Hua , Gao Ying
Published: August 2009

The whole-life design of complex electro-mechanical systems is extremely significant which could satisfy the high reliability requirement of production line and reduce the accident caused by complicated equipments. In this paper, the whole-life of gear was taken as an example to indicate that the sustainable development of whole-life design must rely on the study of few sampling systems. Two research strategies of few sampling systems are proposed: numerical simulation and virtual prototype technology.
Experiments and Numerical Simulation of Hot Bending and Die Quenching for Ultra-High Strength Boron Steel
Authors: Bao Jun , Xing Zhong Wen , Song Bao Yu , Yang Yu Ying , Liu Hong Sheng
Published: August 2009

Hot bending and die quenching for U-shaped parts with ultra-high strength boron steel were experimented and simulated to study its quenching effect and accuracy. The results indicate that through the hot contact bending and die quenching, bending parts with higher strength and forming precision than that of cold stamping can be achieved. And the hot contact bending improves the quenching effect at the bottom of the bending part. The springback of hot contact bending decreases gradually when the blank holder force (BHF) increases, which is mainly negative for the impact of the thermal shrinkage moments. The numerical simulation results are consistent with the experiments’. Therefore, it verifies the reliability of finite element model and lays the foundation for the numerical simulation of the hot stamping process applied in complicated shape parts’ production.
Numerical Study of Springback Laws in Metal Forming of Diaphragm of Automotive Horn
Authors: Zhang Yan Qiu , Jiang S.Y. , Zheng Y.F. , Zhao Li Hong
Published: August 2009

The influences of four parameters such as young’s modulus, yield ratio, punch radius and blank thickness on the springback of diaphragm of automotive horn are analyzed by combining experiment with FEM (finite element method), and the springback laws of the parameters’ interaction are revealed. The results show that the springback of diaphragm is influenced by the yield ratio of material evidently, but is influenced by punch radius slightly when the parameters interact. However, the influence of punch radius increases greatly when the young’s modulus is very low. Therefore, the influence of the parameters’ interaction must be considered so as to control the springback effectively when the forming scheme of diaphragm is designed.
Study for Rectangular Box Drawing of Segmented Variable Blank Holder Force
Authors: Li Xi Ning , Jiang Cheng Yu , Wang Zhong Qi
Published: August 2009

The sheet forming simulation of rectangular box was conducted by finite element method (FEM), the forming process experiment, further, was investigated, so as to understand the effect of the form of blank holder and the manner of blank holder force (BHF) on the complicated parts forming. In my study, a kind of low carbon steel was investigated, and its mechanical properties were obtained by simple tension tests. The outermost contour of the blank shape was determined by “one step method”. Furthermore, the finite element model was constructed by ANSYS parametric design language (APDL), which has characteristic of grid meshing by Belytschko-Tsay (BT) shell element, applying anisotropic constitutive equation of Barlat yield criterion, dealing contact by penalty function method and using adaptive mesh algorithm in the simulation process. Then the forming process simulation of rectangular box with segmented variable BHF was conducted. On the basis of analyzing the work principle and technical parameters of XP3CEF-100 hydraulic press, the rectangular box drawing system of segmented VBHF was established, which was made of hydraulic press, rectangular box drawing die of segmented blank holder, hydraulic part of blank holder and control part. Finally the low carbon steel forming tests were fulfilled by the rectangular box drawing system on the basis of the simulation result.
Effect of Deformation Condition on the Mechanical Behavior of AZ80 Magnesium Alloy
Authors: Wu Y.J. , Zhang Zhi Min , Zhang X. , Wang Qiang , Li B.C.
Published: August 2009

With the deformation temperature between 250°C and 450°C as well as the strain rate between 0.01s-1 and 5s-1, the hot compression tests of AZ80 magnesium alloy were performed on Gleeble-3800 thermal simulation testing machine, so as to seek out the responses of mechanical behavior of AZ80 magnesium alloy under different deformation conditions. The results indicated that AZ80 magnesium alloy shows dynamical recrystallization when hot compessed, the recrystallization is prone to happen and the stress peak decreases with the temperature increased, and the critical strain to produce the transformation of recrystallization augments with the strain rate increased.
Numerical Analysis on Precision Forging of 7A09 Aluminum Impeller
Authors: Wang Wei Wei , Song Jian Li , Han Fei , Luo Shou Jing
Published: August 2009

Numerical simulation and test forming of the isothermal precision forging of an impeller was carried out. The forming processes were simulated with DEFORM-3D to obtain the forming characteristics and metal flow pattern. It indicated that the impeller can be forged by the method of isothermal-forging, and the deforming process can be divided into 3 stages. The forming of blades was depended on the extrusion of materials. During the forming, uneven deformation was existed in the billet, especially in the field of the blade root. The forging load was increased rapidly during the later stage of the forming process, and the maximum forging load was about 2961kN. According to the simulations, the die structure and the billet dimension were determined, the forging die was designed and manufactured, and the precision forgings of the impeller were produced successfully. Both of the simulation and the test forming indicated that the impeller forging could be performed with the assembled structure die and the isothermal extruding forming style satisfactorily. The ideal parameters to produce the precision forgings of the impeller are: a forging temperature of 450°C and a punch speed of 1mm/s. Under these conditions, the forgings of the impeller can be produced with full blades, smooth outer surface and good flow line, which can meet the requirements of the precision forging of impellers.
Investigation on Twist of Asymmetric Flanging of Wheel Cowling Tail of Fender and its Influencing Factors
Authors: Lin Jian Ping , Chen Shui Sheng , Han Dong Feng
Published: August 2009

The flanging on both sides of wheel cowling tail of front fender is stretch flanging. An asymmetric flanging model is built according to the asymmetric twist defect in flanging. The strain distribution of the flanging regions, which is analyzed through finite element method (FEM), is in reasonable agreement with related theories. The result shows that the built model is appropriate to investigate the flanging twist defect of the fender. The accuracy of the model is proved by the comparison of the simulation result with the practical production. Also it shows that the severity of the distortion mainly relies on the asymmetry of the fender and some suggestions are proposed on distortion control through the analysis of the factors influencing laws on the distortion angle, which is define to measure the twist, like radius ratio of the two sides of the fender, flanging height, the clearance between the die and punch of the flanging tools, the fillet radius of the flanging die.
Study on the Joint Strength of SiCp/ Al Metal Matrix Composite by Magnetron Sputtering Method
Authors: Chen Rong Fa , Zhao Yi Hong , Shen Zhao Xia , Dai Liang Gang , Zhang Xian Liang , Zhu Rui
Published: August 2009

Transient liquid-phase (TLP) bonding of aluminium-based metal matrix composite (MMC) has been investigated. An attempt was made of using an Ag/Cu /Ag film as an interlayer for bonding to improve the joint strength. The oxide on the surface of SiCp/Al MMC was etched completely by plasma. Ag/Cu/Ag film of 8µm thickness was prepared by magnetron sputtering method on the clean bonding surface in the same vacuum chamber. Compared with the same thickness of single Cu foil and Ni foil interlayer, which are widely used for joining SiCp/Al MMC material, the shear strength of 192.8MPa was obtained, which was 86.5% that of base metal. Discussion was made on the bonding process and microstructure.
Online Stress Test and Residual Stress Analysis of Plate’s Multi-Point Plastic Forming
Authors: Feng X.J. , Liang L.F. , Zhou Yi Jun
Published: August 2009

This paper introduces a method to measure the online strain in the plate shell forming process. It solves the problem that the inside stress online is almost impossible measured in the process of the upper and lower molds forming. The key technology is the design of the moving test frame. This frame can move with the plate’s movement to protect the sensors and ensure the output of the test signal, at the same time, it does not interfere with the shell’s process conditions. It is the first time to apply this method to the large-sized high-strength steel ball shell plate, and it could accurately measure the stress distribution and changes laws within the shell plate under certain specific condition in the process of punching to online stress test and analysis during the punching forming process. The test results show that the periphery of each pressure point is residual tensile stress, and the inside is the residual compressive stress, more evenly distributed. The existence of residual compressive stress is in favor of the anti-fatigue capacity of the plate.
Warm Flow Compaction Forming of Complex Part by Using Binder-Treated Powder
Authors: Hu Chang Xu , Ngai Tungwai Leo , Zheng Jun Jun , Xiao Zhi Yu , Li Yuan Yuan
Published: August 2009

Powder metallurgy process is a net-shape manufacturing technique that can eliminate or reduce machining time. It is economical and environmental friendly since no scrap is being produced and no high energy consuming process such as melting is involved. Unfortunately, conventional powder metallurgy is not capable of producing complex parts. However, a recently developed binder-treated warm compaction technique can overcome this problem by increasing the flowability of the mixed powder. In this study, by using a commercially available water-atomized iron powder, a cross-shaped part was prepared by warm compaction of a binder-treated iron-base powder at approximately 80 °C and then sintered at 1120 °C. Microstructure, mechanical property and shape consistency of the prepared part were examined. Results showed that parts with high density and high green strength can be obtained without significant shrinkage or expansion. The present paper demonstrated that the binder-treated warm compaction process can expand the capability of powder metallurgy techniques to produce complex parts.
On the Microstructure and Impact Properties of Slow Injection A356 Die Castings with Local Pressurization
Authors: Bai Yan Fei , Zhao Hai Dong , Li Yuan Yuan , Kang Zhi Xin
Published: August 2009

Microstructure and impact properties of slow injection A356 die castings with local pressurization have been investigated. The microstructure in the casting different regions were analyzed and compared. The casting impact absorbed energy varies from 1.17 to 2.35J, and is higher than that of other pressure die casting process. Furthermore, fracture mechanisms of different regions in castings are discussed. The results show that, the impact absorbed energy decreases with increase in SDAS. Also significant fluctuations of the impact properties in the thick-walled and local pressurization regions are found.
Microstructure and Tensile Properties of Al-Cu-Si Alloy with Different Solidification Pressures
Authors: Ouyang Xiao Xian , Zhao Hai Dong , Zhang Ke Wu , Li Yuan Yuan
Published: August 2009

Microstructure and tensile properties of as-cast and T6-treated Al-4%Cu-3%Si alloy with different applied solidification pressures were investigated. The pressure has significant effect on the formed microstructure. It is observed that as the pressures increase, the porosities were removed, and the size and the secondary dendrite arm spacing of primary α-Al grains decreased evidently, and the morphology of eutectic Si particles changed from long acicular to small granular type. Hence, the tensile properties of the alloy were improved. The research has shown that the aspect ratio (A.R.) of the Si particles decreased after the solution and aging treatment. The A.R of the Si particles in the alloys with applied solidification pressure decreased more remarkably and this indicated that the Si particles can be more prone to be dissolved into α-Al matrix. Thus, the increase of the elongation was achieved.
Process Optimization of Mid-Density Tungsten Alloy for Injection Process in Metal Injection Molding Based on Numerical Simulation
Authors: Zheng Zhen Xing , Wu Yuan Biao , Xia Wei , Chen Wei Ping
Published: August 2009

In this paper, based on the CAE technology for MIM and fractional factorial design method, the simulation for the filling process was executed in different process conditions by the Moldflow software. And then it was realized that the extent of the effects of the single factor and pairwise interaction between the process parameters on quality of green parts were forecasted. According to that, the relationships of pressure, velocity and time and their optimal combination were researched by the experiments using a FC-80 plastic-Injection-Moulding machine. The experimental results suggested that the pressure, velocity and time have a obvious pairwise interaction which can have more effect on the product than single factor. It was shown that there was a good consistency between the numerical simulation and experiment. The CAE technique and the experiments are combined to optimize the process conditions and improve the part quality automatically by using smaller number of experiments.
Vertical Indirect Squeeze Casting Process of an Al-Cu-Mn Alloy Frame Part
Authors: Li Yuan Yuan , Hu Yong , Zhao Hai Dong , Zhang Wei Wen
Published: August 2009

To decrease weight and increase fuel efficiency, an Al-Cu-Mn alloy frame part with vertical indirect squeeze casting process was fabricated to replace original parts with spheroidal graphite iron, which is used in a special vehicle. Mold filling of the frame with pouring temperature of 700°C and injection velocity of 0.03m/s was simulated. According to the results vents and overflows were designed and the dies were produced with H13 steel. Furthermore, the casting trial producing was conducted. Cross sections of the castings were checked. A number of specimens were obtained from different parts of the castings to evaluate microstructure, and both high dense and fine grain microstructures were found in the specimens. Mechanical properties of the tensile samples with T5 heat treatment were measured, and the average tensile strength and elongation were 387 MPa and 8.8%, respectively.