bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Thermal Placement Optimization of Embedded MCM
Authors: Huang Chun Yue , Li Tian Ming , Liang Ying , Wei He Geng
Published: February 2011

In the thermal design of embedded multi-chip module (MCM), the placement of chips has a significant effect on temperature field distributing, thus influences the reliability of the embedded MCM. The thermal placement optimization of chips in embedded MCM was studied in this paper, the goal of this work is to decrease temperature and achieve uniform thermal field distribution within embedded MCM. By using ANSYS the finite element analysis model of embedded MCM was developed, the temperature field distributing was calculated. Based on genetic algorithms, chips placement optimization algorithm of embedded MCM was proposed and the optimization chips placement of embedded MCM was achieved by corresponding optimization program. To demonstrate the effectiveness of the obtained optimization chips placement, finite element analysis (FEA) was carried out to assess the thermal field distribution of the optimization chips placement in embedded MCM by using ANSYS. The result shows that without chips placement optimizing the maximum temperature and temperature difference in embedded MCM model are 87.963°C and 2.189°C respectively, by using chips placement optimization algorithm the maximum temperature drop than the original 0.583°C and the temperature difference is only 0.694°C . It turns out that the chip placement optimization approach proposed in this work can be effective in providing thermal optimal design of chip placement in embedded MCM.
Design of Virtual Oscilloscope Based on S3C2410
Authors: Shi Shu Lin , Pi Guo Rui
Published: February 2011

: This topic has designed a kind of virtual oscilloscope based on the embedded technical. On the hardware the S3C2410+IDT7204 structure were used, on the software real-time operating system uC/OS-II were used in the design of embedded virtual oscilloscope. ARM9 microprocessor's high speed handling ability are fully used, as well as FIFO in the read-write control logic, the superiority in high speed data exchange aspect, realizes the double channel synchronization profile demonstration. the multi-task run and the real-time processing were realized by using on the uC/OS-II operating system's in ARM9 microprocessor transplant. This oscilloscope has the cost lowly, to be possible to as the common oscilloscope, also to be possible to as an intelligent module the merit which used in the embedded system.
Determination of Flow Stress Based on Cutting Simulation and Optimization
Authors: Yuan Yue Feng , Chen Wu Yi , Liu Dong
Published: February 2011

A new simple methodology to determine the flow stress of material is presented and Johnson–Cook (JC) constitutive model of titanium alloy Ti6Al4V is obtained via this approach. The JC model is verified by comparison between simulations and experiments. The results show that the model is suitable for cutting simulation. This simple method can be used to determine conveniently JC model not only in the scientific research but also in the workshop production.
A Method of the Inverse Evaluation for Heat Transfer Coefficient between Al-Cu Alloys and Cooling Water
Authors: Hou Zhong Lin , Li Ting , Qiao Jun , Li Sheng Li
Published: February 2011

The heat transfer coefficient between the alloys and cooling water is affected by a lot of factors and hard to measure, a new method was investigated with a self-designed system ultilizing SP-15 high-frequency inductive heating unit. Based on measured temperature curves and Fourier heat transfer model, quantitative correlation between heat transfer coefficient and temperature was obtained by inverse algorithm method of iterative simulation and automatic optimization. The results showed that in submerged water-cooling process, the heat transfer coefficient reached to a peak value at the beginning and then decreased with increasing temperature. A decrease of cooling water temperature increased the peak value of the heat transfer coefficient, but did not change temperature range of the peak value from 200°C to 225°C . The heat transfer coefficient was mainly dependent of interfacial temperature between the Al-Cu alloys and the cooling water.The temperatures range from 200°C to 225°C gave the highest heat flux transfer.
Simulation of Multiscale Time and Space in Fracture Process of Three-Point-Bending Concrete Beam with Offset Notch
Authors: Zhang Rui , Tang Zhi Ping
Published: February 2011

In order to accurately analyze the dynamic damage process of three-point-bending concrete beam with offset notch, the multiscale numerical model of time and space by coupling Discrete Element Method (DEM) and Finite Element Method (FEM) of three-point-bending concrete beam with offset notch was established. Using the multiscale numerical model of three-point-bending concrete beam, the generating and the extending processes and rules of cracks in concrete beam under condition of different offset distances of notch were analyzed at macro- and meso-levels. The simulated results are in accordant with the experimental ones. Comparing the computation time of the multiscale model and that of the DEM model in the example of three-point-bending concrete beam, the former accomplished the heterogeneous mesoscopic simulations of the latter, at the same time, the former was much more efficient than the latter.
Calculation of Static Safety Coefficient about Loess Cave
Authors: Li Jun Hong
Published: February 2011

For the loess cave characteristics, such as the thin coverage soil layer at the hole top, the poor self-stabilizing capacity, the large disturbance deformation after excavation and the easy collapse, thus in this paper, the loess cave safety factor is obtained by the method of strength reduction. And the stability calculation analysis is much more perfect. The Northwest Area Lishi loess cave is used in this paper, and the idea of strength reduction finite element method is applied, based on the Drucker-Prager yield criterion, the loess cave static stability analysis is made by the software of ANSYS.The results show that the actual situation can be reflected by the method of finite element strength subtraction. And the obtained loess cave stability coefficient is much closer to the actual steady state, thus showing the certain advantages of stability analysis.The method is also adopted in this paper. And its feasibility can be applied to the engineering practice, also a theoretical basis of reference is provided for engineering application.
Influence of Wall Thickness Fluctuation of Pierced Shell on Continuous Tube Rolling Process of Semi-Floating Mandrel Mill
Authors: Yin Yuan De , Li Sheng Zhi , Kang Yong Lin , Li Yang Hua , Long Gong Ming , Deng Pi An
Published: February 2011

In continuous tube rolling process, wall thickness reduction per stand will be changed due to wall thickness fluctuation of pierced shell caused by piercing process, which results in changes in metal flow conditions and affects force parameters, deformation parameters, especially transverse wall thickness precision of rolled hollow tube. In this paper, with the aid of commercial FE code MSC.SuperForm, the high pressure boiler steel tube continuous rolling process of a typical hollow tube specification 133.0×4.0mm are simulated based on 133 main pass sequence of 89mm 6-stand semi-floating mandrel mill, and force parameters, equivalent plastic strain, transverse wall thickness precision, outline dimension and real roundness of rolled hollow tube are analyzed and compared on the condition of two different wall thicknesses of pierced shell. Analysis results indicate that force parameters increase with wall thickness of pierced shell, maximal rolling force, rolling moment and mandrel axial force increase 10% or so in the first three stands when rolling pierced shell of wall thickness 11.5mm compared to that of wall thickness 10.5mm. When rolling pierced shell of wall thickness 10.5mm, there exist front and back tensions among the third, the fourth and the fifth stands and outline dimension and real roundness of rolled hollow tube is slightly better. However, transverse wall thickness of rolled hollow tube at the bottom of groove is pulled thin obviously.
Multi-Dimensional Numerical Simulation of Emission Characteristics in DI Diesel Engine
Authors: Cheng Wen Ming , Li Gang
Published: February 2011

In addition to the traditional test methods, numerical simulation the combustion process of internal combustion engine based on experiment, which have the advantages of short period, fast result, low cost and huge Information, has been an important means to study the flow field of engine and the effect of flow field to the emissions. The combustion process and emission characteristics of DI diesel were calculated using CFD software – FIRE. Some important research information, including the distribution of temperature field and exhaust emission concentration as well as the course of emission growth, were got and analyzed detailedly as a predictable reference for improving the structures and emission characteristics of existing DI diesel and developing the new combustion systems.
Study on Creep Deformation of Reactor Coolant Pump Rotor-Can during Vacuum Hot Bulge Forming Process
Authors: Zhu Zhi , Zhang Li Wen , Song Guan Yu , Wu Dong Jiang
Published: February 2011

In this paper, a two-dimensional nonlinear thermo-mechanical coupled finite element model was developed to simulate the vacuum hot bulge forming process of rotor-can with the aid of finite element software msc.marc. A set of stress relaxation experiments were conducted to test the high temperature creep properties of hastelloy c-276 and the creep law of material was defined. Then, the finite element model was used to study creep deformation of rotor-can during vacuum hot bulge forming process. As a result, the temperature field and the stress-strain field are calculated and analyzed. Furthermore, the effects of holding temperature and holding time on creep deformation are also investigated. The optimal holding time range for the vacuum hot bulge forming process of rotor-can is from 2h to 3h.
Imitative Farmland Random Vibration Analysis on Frame of Blueberry Harvesters
Authors: Wang Qian , Li Zhi Peng , Chen Wei Jia , Peng Tao
Published: February 2011

This paper uses MATLAB Simlink module to simulate road spectrum of the blueberries farmland where blueberry harvesters are running, and gets white noise random road displacements. On the basis of ANSYS software, the finite element model of frame of blueberry harvesters is established to carry out imitative farmland random vibration analysis. According to the results from random vibration analysis, improves the structure of frame of blueberry harvesters.
Research on the Application of Expansion Ratio Analysis for Die-Face Optimal Design in Sheet Metal Forming
Authors: Chen Lei
Published: February 2011

In deep drawing process, the experimental approach to obtain proper die-face design is not only expensive, but also requires much time and effort. Numerical simulation of the die-face design using expansion ratio analysis (ERA) can provide an avenue for lowering the cost and increasing the speed of the design process. A finite-element model of four-node quadrangle element is developed based on static implicit method using the Finite Element Code Marc. By the use of the model, the die-face design of oil pan deep drawing process is simulated. The relationship between the ERA and the maximum thickness variation is obtained. The smaller the ERA, the smaller the maximum thickness variation can be acquired. The mission success rate of the forming process increases, too. All the simulation results show reasonable agreement with the experiment.
Mechanism for In Situ Iron Nanoparticles Formed during Copper Alloy Solidification
Authors: Wang Qiang Song , Song Zhuo Fei , Feng Zai Qiang , Wang Zi Dong
Published: February 2011

In-situ iron nanoparticles can be formed during copper alloy solidification. Here we consider ZCuSn3Zn8Pb6Ni1FeCo alloy and demonstrate that high undercooling is the motive power of nanoparticles during solidification , which would act as heterogeneous nuclei to achieve outstanding contribution for grain refinement compared to ZCuSn3Zn8Pb6Ni1alloy. Convection of the melt inhibit the growth of nanoparticles by way of prohibitting the deposition of iron atoms on the surface.This technique offer new enlightenment for the control of in-situ nanoparticles formed during alloy solidification,and also opens the door to a new class of dispersed nanoparticles strengthened materials.
Investigation of Coupling Efficiency by Plastic Deformation of Tube Packaging for Thin-Film-Based Passive Optical Components
Authors: Wang Sheng Ching , Liou Chiou Lin , Tsai Hsi Hsun
Published: February 2011

Thin film based passive optical components assembled with a stainless steel tube via soldering is investigated under a packaging procedure. Finite element analysis is utilized to simulate the packaging procedure in the present study. Mismatch of the coefficient of thermal expansion among various components could induce residual stress over the assembly structure. Coupled thermal-elastoplastic analysis is adopted to predict the plastic deformation of the structure under the solidification process of solder joints. This post-solder-deformation could deteriorate the associated coupling efficiency due to the mis-alignment of the optical fibers. Temperature-dependent mechanical properties of the solder joint are employed in the simulations. Both two-dimensional plane strain and three-dimensional solid models are implemented into the analysis for comparisons. In order to improve the fiber alignment, and thus the coupling efficiency, a three-point bending device is externally loaded on the structure. Unloading procedure is subsequently performed to evaluate the ultimate deformed shape of the structure. Measurements of the insertion loss will be conducted using a power meter in the near future, while a correlation between the coupling efficiency and the fiber alignment can then be expected.
Investigation of Mold Temperature Affecting on Shrinkage of Rapid Heat Cycle Molding Plastic Part
Authors: Liu Dong Lei , Shen Chang Yu , Liu Chun Tai , Xin Yong , Sun Ling
Published: February 2011

In order to further investigate the influence of mold temperature in rapid heat cycle molding on shrinkage of plastic past, a self-developed vehicle-used blue-tooth front shell high-gloss mold and an auxiliary device for controlling the mold temperature were employed in experiments. And the effect of the other parameters on shrinkage of part with fixed or changed mold temperature conditions was also studied. Results reveal that the shrinkage of RHCM part is reduced obviously compared with a conventional one, decreasing as quasi-linear with mold temperature increased gradually. At same mold temperature conditions, packing pressure, followed by packing time, is the most significant parameter on shrinkage of part, while cooling time has almost no impact on it. Melt temperature and injection pressure effecting on shrinkage of part exists a critical value, near the thermal deformation temperature of plastic. When mold temperature is set below this temperature, injection pressure has more significant than melt temperature, but it is the opposite. With being elevated gradually of mold temperature, shrinkage of part shows a slight decrease trend under same melt temperature and injecting pressure. While it fluctuates as a “V” shape with a narrow range under same packing pressure, packing time and cooling time presumed conditions, and reaches the minimum near the thermal deformation temperature of plastic.
Study on Machinability and Polishing Performance of 1CrMn2MoVTiB Non-Quenched and Tempered Plastic Mould Steel
Authors: Gao Cai Ru , Zhang Shun Hu , Wang An Yang , Zhao De Wen
Published: February 2011

Based on the cutting and polishing comparison experiments, the machinability and polishing performance of 1CrMn2MoVTiB non-quenched and tempered plastic mould steel were studied. The cutting comparison experiment showed that the plastic mould steel that had developed recently was better than P20 both in surface roughness and cutter wear; and the polishing experiment indicated that the surface roughness of the two plastic mould steels reached uniformity under the conditions that TriDent polishing fabrics and W0.5 polishing compound were adopted.
Maintenance Process Simulation Model Considered Sharing Resource and its Application
Authors: Qu Chang Zheng , Liu Rui , Zhang Jian Rong , Dong Yue
Published: February 2011

To study the maintenance resources deployment optimization, the resource usage characteristic was analyzed and a maintenance process model was constructed considering multi-team sharing test equipment. Applying model, the quantitative analysis was made and the maintenance performance of different resources deployment was provided.
Optimal Design of the Guide Mechanism of Vertical Ring Rolling Mill
Authors: Wang Xiao Kai , Hua Lin , Zhu Chun Dong
Published: February 2011

This paper firstly analyzes the features of the spring-loaded type guide mechanism of D51 series vertical ring rolling mill. Then a reliable parametric virtual prototyping model of the guide mechanism is developed in software ADAMS. In addition, the optimal design of the guide mechanism is conducted. The minimum spring force is selected as the objective function, the dimensions of the parts of the guide mechanism are set to the design variables and the working condition is taken as the design constraints. The optimal guide mechanism is obtained after optimization, compared with the original structure, the spring force is decreased by 50.5%, and the guiding force is also decreased to a reasonable value. The research results can help to design the guide mechanism of the D51 series vertical ring rolling mill.
Corrosion Characteristics of PEO Films on AZ31 Magnesium Alloys
Authors: Wang Li , Chen Li , Fu Wen
Published: February 2011

The aim of this work is to discuss the corrosion characteristics of plasma electrolytic oxidation (PEO) films formed on AZ31 magnesium alloys in alkaline silicate solution. The uniform and pitting corrosion resistance of the PEO films was investigated by potentiodynamic polarization tests and potentiodynamic scanning curve tests. The composition, the structure and the element contents of the films after immersed in 3.5 wt.% NaCl solution for different time were investigated by XRD、SEM and EDS. The results indicated that the corrosion occurred on AZ31 magnesium alloy and treated PEO samples during five days immersion, but the corrosion tendency of the PEO treated samples is smaller than that of AZ31 magnesium alloy.
Research on Workshop Scheduling of SMT Product Manufacturing System
Authors: Wu Zhao Hua
Published: February 2011

In this paper, taking workshop scheduling of SMT product manufacture system for object, the conception of resource cost is incorporated with Petri Nets. The workshop scheduling model of SMT product manufacture system is build based on transition timed Petri Nets (TC-TPN). ω1 proportion of processing cost, ω2 proportion of processing time, ω3 mutation factor are chosen as the key factors using the improved heuristic A* scheduling algorithm. The result shows that: considering the processing time preference, when ω1=0.7, ω2=0.2, ω3 =0.1, the processing time is reduced by 5.83%, 3.45%, the processing time is decreased by 6.14% and 2.94%; however, considering the processing cost preference, when ω1=0.1, ω2=0.8, ω3 =0.1, the processing time is reduced by 1.94%, 0.86%, the processing time is decreased by 8.06% and 7.52%.
Numerical Simulation of Casting Process for Gray Iron Butterfly Valve
Authors: Li Hai Peng , Liang Chun Yong , Wang Li Hui , Wang Hong Shui
Published: February 2011

During casting process design, CAD/CAE technology can play important role to avoid macroscopic irregularity, internal defect and assure casting performance. Based on the casting process analysis and gating system design, the numerical simulation of gray iron butterfly valve was done by hydrodynamic software Flow-3D to obtain its optimal process scheme. According to the simulation results including flow field, temperature field and defect distribution, the merits and faults of designed schemes were investigated and then the feasible gating system was proposed. The results showed that, compared with top or intermediate casting, when adopting bottom casting, steady flow of molten metal and reasonable temperature distribution could be achieved. And workpiece defects mainly distributed in riser. The predicted results are in good agreement with practical ones.
Microstructure of AZ31 Magnesium Alloy Produced by the CONFORM Process under Different Extrusion Wheel Velocities
Authors: Yang Jun Ying , Song Bao Yun , Ning Hai Shi , Fu Rong
Published: February 2011

It is widely known that the continuous extrusion forming (CONFORM) process can produce ultra-long seamless products of various cross-sections for aluminum, copper and their alloys. In this paper, the continuous extrusion of AZ31 magnesium alloy is achieved. The effect of extrusion wheel velocity on microstructure of extrusions is investigated. The results indicate that grain refinement is realized during CONFORM process. As the extrusion wheel velocity increases, the grain size at the center of a cross section perpendicular to the extrusion direction of an extrusion increases, and the grain structure tends to become uniform in the surface region.
The Mechanism and Influence Factors of Struvite Precipitation for the Removal of Ammonium Nitrogen
Authors: Huang Hai Ming , Song Qian Wu , Xu Chun Lian
Published: February 2011

Struvite (MgNH4PO4∙6H2O) is an insoluble double salt. It can precipitate in places such as pipes, aerators and pumps, which could lead to substantial problems influencing the normal operation of wastewater treatment equipments. At present, removal of ammonium nitrogen from various wastewaters by the formation of struvite has been widely investigated. This paper reviewed the research and application efforts concerning the treatment of ammonium nitrogen by struvite precipitation, which were obtained at home and abroad in recent years. The mechanism and influence factors of struvite precipitation for ammonium nitrogen removal were discussed. Additionally, the problems that still should be resolved and the research directions in future were pointed out.
Study of Solutions and Causes for Scrap Jumping up in High-Speed Stamping
Authors: Li Hong Lin , Tang Ting Xiao
Published: February 2011

High-speed sheet metal stamping is popular because it is economical and quick means of producing intricate, accurate and durable components in large quantities. Scrap jumping up is one problem which usually occurs in high-speed stamping manufacturing processes. In this paper, the relevant factors are analyzed and studied such as the press tool, the shape and size of the stamping pieces, the structure and rigidity of pressing die, the clearance between punch and die, material properties of the blank, etc. Then ten cases are summarized that lead to scrap jumping up. For each case, corresponding solution is presented to avoid the scrap jumping up.
Process Research on High-Speed Small Hole Drilling by EDM Combined with Magnetic Field and Water Dispersant
Authors: Cao Ming Rang , Geng Xiao Di
Published: February 2011

The mechanism that the magnetic field and the dispersant are helpful to chip removal, to improve the material removal rate (MRR) and to reduce the tool wear rate (TWR) was analyzed in detail.The corresponding experiments were conducted based on theoretical analysis. The experimental results show that adding a certain proportion of dispersant into the dielectric fluid and introducing the magnetic field for high speed small hole drilling by EDM can greatly improve the material removal rate and significantly decrease the tool wear rate.
Function Analysis of Injection Molding
Authors: Li Ji Quan , Hu Yan , Kong Ying , Jiang Shao Fei , Chen Chuan
Published: February 2011

The function of injection molding process is described in the quality, function and costs of injection products from the definition of function. Detailed analysis and evaluation are taken to investigate these three aspects, and the aspect of injection products quality is principally discussed. The analysis and evaluation of injection molding process function will be kept as the judgment of quality of the process.
Microstructure and IR Studies of Ag Ions-Zeolite
Authors: Fan Yan Hua , Xiong Kai , Dong Li Hua , Yin Yan Sheng , Li Wen Ge
Published: February 2011

Ag-zeolite crystal have been obtained through immersing Na86–X (Na86[(AlO2)86(SiO2)106]46.2H2O) zeolite in 0.1 M AgNO3solution for 12 h. Information on the interaction of Ag+ cations with framework oxygens was obtained by analyzing of IR spectra. SEM and EDS reveal that the microstructure of zeolite is tetrahedral with some little cluster between tetrahedral crystal and Ag element exists in the crystal.
Design and Realization of Automatic Testing System for Hydraulic Pump
Authors: Wang Cheng Long , Zeng Qing Liang , Zhou Guang Yu , Zhao Sheng Gang
Published: February 2011

Based on the application analysis of hydraulic pump CAT test-bench, an automatic testing system of hydraulic pump CAT test-bench combined with technology of measurement and control was raised, including the detailed introduction of its work principle, components and software. By this testing system, tests of hydraulic pumps were realized automatically, accurately and efficiently.
Preparation and Oxide CMP Performance of Inorganics Coated Polystyrene Composite Particles
Authors: Chen Yang , Chen Zhi Gang
Published: February 2011

CeO2-coated Polystyrene (CeO2/PS) and SiO2-coated Polystyrene (SiO2/PS) composite particles were synthesized by chemical precipitation method. The as-synthesized composite particles samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA) and Zeta potential measurement. The oxide chemical mechanical polishing (CMP) performance of the as-papered composite particles was studied by atomic force microscope (AFM). The results indicated that CeO2/PS composite particles had core-shell morphology and PS particles were uniformly coated by fluorite-structured CeO2. The Strawberry-shaped SiO2/PS composite particles were obtained, which particle size is about 200-300 nm. Surface roughness (RMS) within 5 μm×5 μm area of thermal oxide film surface after polished by CeO2/PS and SiO2/PS composite particles was decreased to 0.227 nm and 0.222 nm, respectively.
Analysis and Study of Damage of Forging Cracks
Authors: Duan Xing Wang , Liu Jian Sheng , Zhang Xiu Zhi , Zhao Xiao Dong
Published: February 2011

This paper dealt with the outstanding problems which were forging cracks existing in the process of forging.The forming reasons of forging cracks were analyzed. From the perspective of damage mechanics, the conventional mesoscopic models and fracture criteria of ductile metal material damage were introduced. The problems in recent research of forging cracks were pointed out. Some corresponding suggestions for the future research of forging carcks were put forward based on the existing problems. The existed ductile fracture criteria have only predicted the damage of specific process yet ,while the diversities of metal forming processes require ductile fracture criterion to have wide scope of application,so,for reason given above,the emphasis is placed on the necessity of establishing new ductile fracture criteria and fracture parameter library with the method of combination of theory and experiment and numerical simulation.
A New Hybrid Particle Swarm Optimization for Solving Flow Shop Scheduling Problem with Fuzzy due Date
Authors: Tang Hai Bo , Ye Chun Ming , Jiang Liang Fu
Published: February 2011

Coping with the characteristic of flow shop scheduling problem with uncertain due date, fuzzy arithmetic on fuzzy numbers is applied to describe the problem, and then a new hybrid algorithm model which integrate particle swarm optimization into the evolutionary mechanism of the knowledge evolution algorithm is presented to solve the problem. By the evolutionary mechanism of knowledge evolution algorithm, we can exploit the global search ability. By the operating characteristic of PSO, we can enhance the local search ability. The algorithm is tested with MATLAB simulation. The result, compared with Genetic algorithm and modified particle swarm optimization, shows the feasibility and effectiveness of the proposed algorithm.
Research on Warm-Cold Precision Forging Process and Numerical Simulation for Spherical Housing
Authors: Li Qian , Jiang Zhi , Ma Xiao Hui , Yan Hong Yan , Zhong Zhi Ping , Liu Gui Hua
Published: February 2011

The warm-cold forming process is researched for complex-DOJ-type spherical housing by means of numerical simulation. Each step of the process is simulated, especially for the reverse extrusion process. Focusing on analysis of the material flow, temperature distribution as well as the load curve, a reasonable process for DOJ-type spherical housing is obtained. The reasonable forming process for DOJ-typed spherical housing offers favorable basis for forming and mold design.
An On-Line Multiparametric Water Quality Monitoring System Based on Visible Spectrophotometry
Authors: Liao Hai Yang , Tian Peng , Du Yu , Wen Zhi Yu
Published: February 2011

Water quality monitoring plays an important role in contamination control and environment protection. This paper describes an on-line multiparametric water quality monitoring system based on visible spectrophotometry, which combines embedded technology with GPRS telecommunication technology. This system can realize online wireless monitoring to concentrations of chromium (Cr), plumbum (Pb), A surfactant (AS), chemical oxygen demand (COD), ammonia nitrogen (AN), total phosphorus (TP) and total phenol (TPh) in real time. The mechanical structure, hardware circuit and software design of the system are completed. The absorption spectrums of pure water and MB-SDS complex have been measured. Preliminary experiments using a model machine show that each mechanism of the system runs well. Moreover, the monitor possesses many advantages, such as high degree of automation, high reliability, high efficiency, compact structure, small size, and so on.
Finite Element Analysis for the Influence of the Clamping Holder Corner on the Bulging of Thin Metal Shells
Authors: Gao Guang Fan , Chen Jin Shan , Cao Xue Gang
Published: February 2011

Peripherally clamped thin shallow hyperbolic metal shells under internal pressure are widely used as rupture discs, quick opening devices and the structures in metal plastic processing. In the bulging process of shells, if the corner radius of the up-holder is too large, negative-curvature zone close to boundary will be enlarged. Contrarily, if the radius is too small, shear rupture will happen in the clamped rim. The contact between the shell and the up-holder corner in deformation is explored by elasto-plastic finite element analysis, and the results are verified with experiments. Influence of the up-holder corner on the mechanical behavior of bulging shells is closely related to the non-dimensional parameter ru/s0 (ratio of the corner radius ru to the original thickness s0). The influence can be partitioned into four regions by three demarcation points, ru/s0 = 0.52, 1.50, and 2.00. The four regions are respectively full effect region, unstable region, near-stable region, and no effect region.
Study on Cold Extrusion Process and Die for Vehicle Sleeve Gear with Spline
Authors: Zhang Chi , Shang Xin , Xiang Rong
Published: February 2011

This paper mainly looks at the research on cold extrusion process and die of vehicle gear sleeve with spline, optimized the cold extrusion process of the part using FEM analysis, which gives us a theoretical basis for further exploration on the cold extrusion, and selecting optimum process parameters. The optimized results were verified by experiments and mass production. It analyzes the effect of the punch shape of gear container to metal flowing. The plastic flow could be controlled by the selection of the punch shape of gear container which reduced the resistance to deformation, and the gear profile was full without folding defects.
Embedded Web-Based Remote Monitoring System of the Motor
Authors: Liu Hai Lang , Liu Xiao Hu
Published: February 2011

At present the application layer in the network data transmission and expression of the most widely used protocol is Http protocol, embedded devices through the Internet network remote monitoring of data transmission direction to one of the main focus in the Web server for embedded systems. Embedded web server to achieve this, no operating system support, embedded system itself Common Gateway Interface, to complete web page publishing, the most important is the use of embedded devices that can be used as remote monitoring software system.The key equipment for the motor system for remote network monitoring, this paper describes the design of the specific structure of web servers and for system implementation and realization of the key technologies used to give a detailed exposition, in the end PC to run on the results of the test.
Research on a Compiler for NC System Based on PC
Authors: Liu Hai Lang , Lin Cheng De , Wang Ai Zhen
Published: February 2011

With the constant development of numerical control technology, the development cycle and efficiency of CNC (computer numerical control) system is restricted with NC code compiler insufficient in Rapid Development and efficiency. In order to solve this problem, a compiler developed with Lex&Yacc for CNC system based on PC is put forward. This compiler is consisted of a lexical analysis module, a syntax analysis module and an object-storage module. With designed in modules, parameter-driven programming and assisted by Lex&Yacc which is an efficient language for compiler development, this compiler has great advantages such as high efficiency and short development cycle, which mean realistic significance to engineering application. The main principal and design process of every module was expatiated and at last a test of compiling a NC file was executed successfully, which verified the validity of this proposed method.
Experimental Study of Hot Extrusion Micro Gear of Brass H62
Authors: Zhou Xu Dong , Liu Xiang Ru
Published: February 2011

A new micro-forming method, combining a metal’s super-plastic behavior with hot extrudsion technology, has been developed for manufacturing micro-gear from brass H62. The micro-gear, which modulus m = 0.125mm, pressure angle α = 20°, number of teeth z = 6, tip diameter d = 1mm, was selected and its dies were designed with a better die approach angle based on the DEFORM-3D FEA simulation results of the hot extrusion process. Finally the micro-gear was successfully hot extruded at 650°C from blank Φ3mm×3mm with extrusion ratio about 17. A good dimensional accuracy for micro-gear was obtained by using this hot extrusion technology. In the special die set, the split die structure was designed, and the special die materials were chosen, such as the pressure ram was made of tungsten carbide, and the other dies were made of mold materials 4Cr5MoSiV1.
The Desing and Research of the Interior Sprue Gate of Die-Casting Mould
Authors: Zhang Xiao Yan , Zhu Cheng Jun , Shang Chang Pei
Published: February 2011

In the design of die casting mould，the design of the interior sprue gate is very important. The high-velocity filling operation of metal liquid and flow order are the main factors of determining product quality in the die-casting process. Based on the working experience for many years, after carrying on investigation, counting, analyzing a lot of moulds that have been proved through production, think:In all factors of design of the interior sprue gate, the position, direction, dimensions, sectional shape are four important factors.
Effect of Molding Parameters on the Interface Morphology of Metal Co-Injection Molding
Authors: He Hao , Li Yi Min , Wang Guang Yao
Published: February 2011

In the present study, the effect of injection temperature, velocity and delay time on the interface morphology of the co-injection molded plates was studied. The results showed that the core penetration parallel to the flow direction becomes less as the skin injection velocity and temperature increases and delay time decreases. Among the parameters, temperature was the most significant in affecting the interface morphology, followed by delay time, while injection velocity seemed to play no significant role. The results were analyzed by taking account of rheological properties of the two feedstocks. Calculations and comparisons of viscosity ratios encountered in experiments were made. It was demonstrated the differences in the rheological properties of the metal feedstocks involved are key factors in determining the interface morphology of the molded parts.
Development of Experimental Method to Improve Sheet Metal Formability by Transverse Normal Stress
Authors: Wang Zhe , Lai Xiao Ming , Wang Zhong Jin , Cui Qing Xin , Li Wen Tao
Published: February 2011

To make full use of the promotion potential of hydrostatic stress on the formability of sheet metal, several foundational questions met in practical application of double-sided pressure forming technique are studied in this paper. The theoretical analysis of sheet metal deformation during the double-sided pressure bulging process is carried out, and an analytical approximation for normal pressure loading path that secures out-of-plane stress ratio, γ, continuously increasing (dγ ≥ 0 holds) is presented. Utilization of the relationship between the theoretical approximation for normal pressure load and material hardening properties, a novel double-sided pressure forming method is proposed—the viscous pressure bulging (VPB) of the overlapping sheet metals, in which a highly viscous but flowable semi-solid medium is used as the soft die and the target sheet metal is deformed under the constraints from viscous medium on one side and overlapping sheet on another side. To confirm the efficiency of the proposed method, the VPB test of overlapping sheet metals is simulated by DEFORM-2D, and the experimental tests are also carried out. The results show that σ3 provided by overlapping sheet can overcome the diminishing of γ value caused by evolving strain-hardening and geometric softening effect in the post-diffuse necking stage. The experimental obtained increase of the limit dome height (LDH) of double-sided pressure bulging specimen is 12.6% compared with that of single-sided pressure bulging specimens.
Study on the Metal Flow in Power Spinning Process of Parts with Transverse Inner Rib
Authors: Ma Fei , Yang He , Deng Qiang , Zhan Mei , Hu Li Jin
Published: February 2011

In this paper, by using a practical 3D FE model, one power spinning process of parts with transverse inner rib has been simulated. The stress and strain fields have been obtained and the features of metal flow in plastic deformation zone have been discussed thoroughly. Then, the main forming defects and their origins have been explored based on the study of the metal flow, shown as follows; (1) during the non-rib process, the main forming defect is the wall fracture in finished deformation zone. The origin of this forming defect is the excessive metal flow in thickness direction ahead of the forming roller. (2) in the rib-forming process, the main forming defect is the undesired inner rib. The origin of this forming defect is the excessive metal flow in hoop direction during the former non-rib process. (3) the features of the metal flow during flange part process are almost the same as those in the non-rib process. The achievements of this study can thoroughly reveal the deformation mechanism and provide an important basis for the optimization of the process parameters and the precise control of the power spinning process of parts with transverse inner rib.
Determination of Optimal Microminiature Powder Injection Molding Parameters by Taguchi Approach
Authors: Li Haw Pei , Muhamad Norhamidi
Published: February 2011

The global manufacturing trend is now focusing towards miniaturization. Microminiature Powder Injection Molding (μPIM) is a viable technology to fabricate complex and high performance miniaturized components. The μPIM technique was used to produce the near-net shape micro components in this study. Fine stainless steel powder with particle size of 5μm was mixed with a ternary water-based binder system. Micro dumbbells with the largest dimension of 9mm were replicated. In order to obtain successful and well molded micro dumbbells, the Design of Experiments (DOE) technique was applied to investigate the optimal parameters in injection molding process. Injection parameters such as injection pressure (A), injection temperature (B), powder loading (C), mold temperature (D), injection time (E) and holding time (F) were optimized by using stainless steel feedstocks. Taguchi approach is chosen and the results were evaluated with signal-to-noise (SN) ratio and analysis of variance (ANOVA). The results show that the feedstocks could be replicated by using μPIM method with the application of Taguchi approach.
Ultrasonic Elliptical Vibration Turning Studty for Precision and Ultra-Precision Workpiece
Authors: Li Wen , Yan Lin Song , Zhang De Yuan
Published: February 2011

Based on ultrasonic elliptical vibration cutting (UEVC) model, kinematical formulas of elliptical vibration cutting(EVC) is established, the paper presented relationship of vibration parameters effecting on surface roughness, machining accuracy and machining efficiency, revealed UEVC characteristics of high frequency and small amplitude are more conducive to improve surface roughness, advance EVC machining efficiency. Experiences of cutting the weak rigidity workpiece by the designed adjusting frequency elliptical transducer is proved that compared conventional turning, increasing vibration frequency and decreasing amplitude are result in improve surface roughness, and compared low frequency EVC, decrease amplitude are result in reduce the height of vibration ripples in cutting direction, and advance machining efficiency. So high frequency and small amplitude EVC is more conducive to precision machining and ultra-precision machining.
The Research of a Drill Bit for Underground Casing Drilling in Radial Water Jet Penetration Perforation
Authors: Zhu Lin , Xiao De Ming
Published: February 2011

The drill bit for underground casing drilling was taken as object of study, and systemic research have been done for N80 casing drilling in Radial water jet deep penetration perforation. A new drill bit was designed after researched the actual drilling conditions, the characteristic of current commonly used drill bits and the property of blades edge materials. The reasonable original-edge angle, cutting parameters have been obtained for the new drill bit. We choose some other commonly used drill bit, and then contrast experiments result have been done by the new drill bit. The test results show that the new drill bit have the advantages of centering reliable, drilling smooth and sub-chip completely, and it can meet the requirements of the down hole casing drilling.
Study of Microstructure and Adhesion Strength of WC-Co Coating Sprayed by High Velocity Oxygen Fuel
Authors: Zhang Mei Lin , Zhao Ming Wei
Published: February 2011

WC-12 %Co powders were sprayed by high velocity oxygen fuel (HVOF) to prepare coatings on carbon steel substrate, which was pretreated by electrospark and grit blast before spraying. The surface coating of WC-Co and the intermediate layer structure were studied by scanning electron microscopy and X-ray diffraction. The adhesion strength of the coating was measured by a scratching tester. Results show that the roughness value of the grit blasting and electrospark strengthened surface were 60~70 μm and 40~50 μm, respectively. The coating pretreated by grit blast and electrospark was dense and was bonded well with the substrate. The heat affected zone of the grit blasted specimen was larger than that of the electrospark pretreated one. The average adhesion strength of the coating pretreated with grit blasting and that with eletrospark were 35.00 N and 12.48 N, respectively. The reasion of the high adhesion strength of the grit blasting coating is discussed.
The Effect of Two-Step Aging on the Electrical Properties of 7075 Aluminum Alloy
Authors: Zhong Jian Hua , Xiao Yin Ping , Zhu Hong Bin , Feng Kai
Published: February 2011

This experiment has taken a research on the conductivity changes of 7075 aluminum alloy after being extruded and two-step aging treatment,and has done a analysis on the theory and rules of the impact on conductivity performance under the two-step aging treatment.Compared to cast aluminum alloy and extruded aluminum alloy without two-step aging process,the experiment showed that extruded alloy with two-step aging treatment has the highest conductivity about 44% IACS, 33.3% more than under casting condition and 22.2% more than only being extruded.
Influence on Cutting Forces and Vibration in High Speed Machining Pocket Corner
Authors: Tang De Wen , Peng Ru Shu , Zhao Rui Lan
Published: February 2011

High speed milling hardened mould steel (above HRC50) at pocket corner generates the cutting forces increase and vibration gets fiercely because of the sudden change of cutting direction. It will cause serious wear and possible breakage of cutting tool, and poor quality of parts. Hence, the need to select reasonable cutting parameters and adopt appropriate cutting strategies will help them to achieve their goal. In this paper, the effects cutting parameters including cutting speed, pocket corner angle, feed rate per tooth and radial depth of cut on cutting force and vibration are studied. The results show that sharper pocket corner results in the increase of cutting force and makes vibration strong. Cutting force increase with the increase of cutting speeding, feed per tooth and radial depth of cut. The optimum of cutting speed leads to the decrease of vibration. It is proposed that cutting parameters should be optimized to improve tool life and processing efficiency.
Study on Decreasing Processing Cost of Special-Shaped End Socket
Authors: Xu Li , Yang Guang
Published: February 2011

Making processing the surface of special-shaped end socket which is made of zirconium diboride ceramics cost too much by old method.A series of processing experiments were conducted and a advance cnc machining technique was described in this paper. Most reasonable machining parameters were given after orthogonal test and analysis of range.To use these machining parameters in processing the surface, the processing cost can be reduced greatly with a high machining efficiency.
Nano-Process of SiC Ceramics by Molecular Simulation
Authors: Liu Guo Zhi , Zhang Ke , Tang Yu Lan , Sun Hong , Gao Hai Yan
Published: February 2011

SiC ceramics have been widely used in a variety of areas due to the excellent physical and chemical properties. However, the process of SiC ceramics is difficult and high-cost, molecular simulation is an effective and feasible method to study the nano-process of SiC ceramics. In this paper, a molecular model is presented to simulate the stress and energy in the nano-cutting of SiC ceramics. The influences of the cutting depth and cutting speed on the kinetic energy and potential are analyzed. The results show that potential energy increases with the decrease of the cutting depth. Kinetic energy increases with the increase of the cutting speed. The results are very helpful for improvement the level of ultra-precision processing and nano-processing of brittle ceramics.