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A new composite:spray-deposited M2 high speed steel reinforced by WC particles

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International Journal of Minerals,Metallurgy and materials 1997年第3期11卷 14-17页

作者： ZHANG Liying TIAN Haige HUANG Thuo WU Chengyi (material science and Engineering school, {3. of science and Technology beijing, beijing 100083. china) Univ of science and Technology Beijing Beijing China

The fabrication of the high speed steel matrix composites reinforced by WC particles utilizing the ultrasonicgas atomization and spray-deposition was studied. The change of microstware and mechanical Properties of thecomposites added WC Particles were investigated and analyzed as well. As some results, the WC particles exhibit tWomorphologies (spherical and angular) with different content of WC particles; and with the increase of content of WCparticles, the hardness of the composites increases, yet the bending strength appears a trend of decreasing.

关键词： spray-deposition high speed steel composite

Laser Shock Processing of an Austenitic Stainless Steel and a Nickel-base Superalloy

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Journal of materials science & Technology 2003年第5期19卷 402-404页

作者： Huaming WANG, Xijun SUN and Xiaoxuan LILaboratory of Laser materials Processing and Surface Engineering, school of materials {3. and Engineering, Beihang university (formerly beijing university of aeronautics and astronautics), beijing 100083. china Lab. of Laser Mat. Proc. Sch. of Mat. Sci. and Eng. Beijing Univ. of Aero. and Astron. Beijing 100083 China

An austenitic stainless steel 1Cr18Ni9Ti and a solid solution-strengthened Ni-base superalloy GH3. were shock processed using a Q-switched pulsed Nd-glass laser. Microstructure, hardness and residual stress of the laser shock processed surface were investigated as functions of laser processing parameters. Results show that high density of dislocations and fine deformation twins are produced in the laser shock processed surface layers in both the austenitic stainless steel and the nickel-base superalloy. Extensive strain-induced martensite was also observed in the laser shock processed zone of the austenitic steel. The hardness of the laser shock processed surface was significantly enhanced and compressive stress as high as 400 MPa was produced in the laser shock processed surface.

关键词： Laser shock processing Austenitic stainless steel Nickel-base superalloy Surface mechanical properties Residual stress

Sintering Mechanism of Stainless Steel in Powder Injection Molding

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International Journal of Minerals,Metallurgy and materials 2000年第1期14卷 51-54页

作者： Chengchang Jia Shimin Fan Ying Peng Xiaojie Zhao Xiaosen lu material science and Engineering school, {3. of science and Technology beijing, beijing 100083. china beijing Tungsten and Molybdenum Factory, beijing 102206, china beijing Hard Me material science and Engineering school University of Science and Technology Beijing Beijing 100083 China beijing Tungsten and Molybdenum Factory Beijing 102206 China beijing Hard Metal Factory Beijing 100055 China

Stainless steel samples were made by Powder injection Molding (PIM) process with-400 mesh powder in order to investigate the sintering mechanism in this system and develop the PIM of stainless steels. The process included mixing, injection molding, debin- ding and sintering. Neck growth model was used to analyze the sintering mechanism. The results show that lattice (volume) diffusion is the main mechanism in the sintering process, the products with higher density (>95%) and properties are obtained. At lower temperatures, grain boundary diffusion may play a role in the sintering densification.

关键词： sintering mechanism powder injection molding stainless steel, volume diffusion

Numerical simulation of strain localization and damage evolution in large plastic deformation using mixed finite element method

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Journal of university of science and Technology beijing 2004年第3期11卷 273-277页

作者： Zhanghua Chen Jiajian Jin Jiumei Xiao Applied science school, university of science and Technology beijing, beijing 100083. china Applied science school University of Science and Technology Beijing Beijing 100083 China

An investigation of computer simulation is presented to analyze the effectsof strain localization and damage evolution in large plastic deformation. The simulation is carriedout by using an elastic-plastic-damage coupling finite element program that is developed based onthe concept of mixed interpolation of displacement/pressure. This program has been incorporated intoa damage mechanics model as well as the corresponding damage criterion. To illustrate theperformance of the proposed approach, a typical strain localization problem has been simulated. Theresults show that the proposed approach is of good capability to capture strain localization andpredict the damage evolution.

关键词： strain localization mixed element truesdell stress rate material damage

Functionally Gradient material Made by IncrementalMelting and Solidification Process

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International Journal of Minerals,Metallurgy and materials 1999年第3期13卷 205-207页

作者： Chengchang Jia Hongbo Tian Tao Lin Zhimeng Guo Nobuyoshi Sasaki(material science and Engineering school. {3. of science and Technology beijing. beijing, 100083. china)(CADIC Cooperation. Kawasaki, 213. Japan) material science and Engineering school University of Science and Technology Beijing Beijing 100083 China CADIC Cooperation Kawasaki 213 Japan

A new technique IMS (Incremental Melting and Solidification Process) has been introduced. A kind of cast steel high Mn foundry alloy gradient rnalerial was produced by this process. The microstructure and mechanical properties of the alloy were tested. Fe and Mn in the samples were measured by EPMA. The experimental results show that the content and hardness of Fe-Mn alloy vary continuously and the IMS process is an alternative way in producing metal matrix gradient material. It is possible for these materials to be made into some parts such as camshaft.

关键词： IMS process FGM melting solidification

Application and Comparison of SST Model in Numerical Simulation of the Axial Compressors

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Journal of Thermal science 2010年第4期19卷 300-309页

作者： YIN Song~1,JIN Donghai~2,GUI Xingmin~3.and ZHU Fang Aero-Engines Simulation Research Center,school of Jet Propulsion,beijing university of {3. and astronautics, beijing,100191,china Aero-Engines Simulation Research Center School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing China

The shear-stress transport(SST)turbulence model is incorporated into Navier-Stokes equations to simulate a turbomachinery flowfield.A staggered finite volume method is used to make the mean flow equations and turbulence model equations strongly coupled and enhance the stability of the numerical *** implicit treatment of the source terms is applied to the SST model.A steady state solution is obtained using five-stage Runge-Kutta time-stepping scheme with local time stepping and residual smoothing to accelerate convergence. The wall distance d,a key parameter in the SST model,is solved by a partial differential *** validations of the code are conducted on rotor 3.,wp11 at design and off-design conditions by comparison with measurements and the Spalart-Allmaras(SA)turbulence *** flow within the tip is calculated with a multi-block grid.

关键词： SST model staggered finite volume method turbomachinery simulation multi-block grid

Genetic Algorithm for the Thermal Stresses Optimum Design ofFunctionally Gradient material Plate

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International Journal of Minerals,Metallurgy and materials 1999年第3期13卷 224-227页

作者： Xiaodan Zhang Zhengbin Tang Changchun Ge(Applied science school, university of science and Technology beijing, beijing 100083. china) Applied science school University of Science and Technology Beijing Beijing 100083 China

Based on the thermal stress distribution for functionally gradient material (FGM) plates, a Genetic Algorithm (GA) method for the thermal stresses optimum design of FGM plate with computer technologies is given. The m... 详细信息

关键词： functionally gradient material (FGM) thermal stress Genetic Algorithm (GA) crossover mutation

Adaptive RBF neural network control of robot with actuator nonlinearities

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控制理论与应用（英文版） 2010年第2期8卷 249-256页

作者： Jinkun LIU, Yu LU (school of Automation science and Electrical Engineering, beijing university of aeronautics and astronautics, {3. 100191, china) school of Automation science and Electrical Engineering Beijing University of Aeronautics and Astronautics Beijing China

In this paper, an adaptive neural network control scheme for robot manipulators with actuator nonlinearities is presented. The control scheme consists of an adaptive neural network controller and an actuator nonlinearities compensator. Since the actuator nonlinearities are usually included in the robot driving motor, a compensator using radial basis function (RBF) network is proposed to estimate the actuator nonlinearities and eliminate their effects. Subsequently, an adaptive neural network controller that neither requires the evaluation of inverse dynamical model nor the time-consuming training process is given. In addition, GL matrix and its product operator are introduced to help prove the stability of the closed control system. Considering the adaptive neural network controller and the RBF network compensator as the whole control scheme, the closed-loop system is proved to be uniformly ultimately bounded (UUB). The whole scheme provides a general procedure to control the robot manipulators with actuator nonlinearities. Simulation results verify the effectiveness of the designed scheme and the theoretical discussion.

关键词： Adaptive control RBF neural network Actuator nonlinearity Robot manipulator Deadzone

Three-Dimensional and Cross-sectional Characteristics of Normal Grain Growth Based on Monte Carlo Simulation

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International Journal of Minerals,Metallurgy and materials 1998年第3期12卷 129-133,139页

作者： Xiaoyan Song Guoquan Liu(material science and Engineering school, {3. of science and Technology beijing, beijing 100083. china)(Department of materials science and Engineering, Hebei {3. of Technology, Tianjin 3.013., china) material science and Engineering school University of Science and Technology Beijing Beijing 100083 China Departments of materials science and Engineering Hebei University of Technology Tianjin 300130 China

An appropriate Monte Carlo method was developed to simulate the three-dimensional normal grain growth more completely. Comparative investigation on the three-dimensional and the cross-sectional characteristics of normal grain growth was done. It was found that the time exponent of grain growth determined from cross-section exhibits the same rule of increasing slowly with time and approaching the theoretical value n = 0.5 of steadygrain growth as the three-dimensional (3.D) system. From change of the number of grains per unit area with timemeasured in cross-section, the state of 3.D normal grain growth may be predicted. The gtain size distribution incross-section is different from that in 3.D system and can not express the evolution characteristic of the 3.D distribution. Furthermore, there exists statistical connection between the topological parameters in cross-section and thosein three-dimensions.

关键词： Monte Carlo simulation normal grain growth three-dimension cross-section characteristics