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Surface metallurgy of Nickle Base Superalloy

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International Journal of Minerals,metallurgy and Materials 1999年第1期13卷 47-49页

作者： Xu zhang Zhongmin Yang jianxin Dong Xishan Xie Yuan Gao Zhong Xu (Material {2. and Engineering school, university of {2. and technology beijing, beijing 100083, china)(Institute of Surface Engineering, Taiyuan university of technology, Taiyua Material science and Engineering school University of Science and Technology Beijing Beijing 100083 China Institute of Surface Engineering Taiyuan University of Technology Taiyuan 030024 China

The Double Glow Plasma Surface Alloying Technique, the Xu-Tee Process, is a new method to produce high quality alloying layer on the surface of less expensive materials. By using thes technique, the surface alloying layer similar to superalloy Inconel 62. has been obtained on the surface of three kinds of melallic materials (low carbon steel, industrial pure iron, stainless steel Cr18Ni9). The results of the composition and microstructure analyzed by Scanning Electron Microscopy (SEM) and X-Ray Uffrachon (XRD) show that the alloying layer consistS of y matrix and several precipitates (Laves intermetallic phase and carbide etc.). The electrochemical corrosion results show that the surface alloying layer formed on the surface of stainless steel and industrial pure iron have better corrosion resistance than that of nickel base alloy inconel 62. and stainless steel Cr18Ni9 in 3.5%NaCl solution. The exper iments indicate that it is an effective way to obtain the gradient surface alloying layer on the surfaces of steels by using Double Glow Plasma Surface Alloying Technique.

关键词： double glow nickel base alloy plasma surface alloying

Thermochemical Evaluation of Combustion Synthesis of Al_2._3/B_4C Composite

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International Journal of Minerals,metallurgy and Materials 1998年第2期12卷 90-92页

作者： Yonghe Liu~(1,2.) Sheng Yin~(1)) Weijing zhang~(1)) Hoyi Lai~(1)) 1) Materials science and Engineering {2., UST beijing, beijing 100083, china 2. {2. of Materials science and Engineering, Shandong university of technology, Jinan 2.0014 Materials science and Engineering school UST Beijing Beijing 100083 China school of Materials science and Engineering Shandong University of Technology Jinan 250014 China

The equilibrium phase and adiabatic temperature for combustion synthesis of Al_2._3/B_4C employing Al, B_2._3 and C as starting materials is analyzed by both conventional and CALPHAD method. The adiabatic temperature calculed by CALPHAD method is significantly lower than that obtained by conventional method. The CALPHAD calculation also reveals that the equilibrium phases presented at the adiabatic temperature are different to the desired composites. The adiabatic temperature in this system can be lowered by introducing Al_2._3 as diluents. The maximum amount of Al_2._3 that can be added to the system while maintain a self-sustaining combusion mode is 1.3 mol.

关键词： thermochemical evaluation SHS Al_2._3/B_4C composite

Production of O' -sialon-SiC Composites by Carbon Reduction-Nitridation

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International Journal of Minerals,metallurgy and Materials 1998年第1期12卷 26-30页

作者： Haijun zhang Wenchao Li Xiangcong Zhong (Applied science {2., university of science and technology beijing, beijing 1 0008 3, china) Applied science school University of Science and Technology Beijing Beijing 100083 China

The effect of temperature, soak times, carbon and addition on composites was discussed in the process ofsynthesizing O'-sialon-SiC by carbonthermal reduction-nitration from nature kaolin. It showed that the fracturestrength (MOR) of composites sintered under certain conditions can be up to 140MPa at room temperature. Thetarget parameter optima regions with good mechanical properties of this material were also indicated by usingcomputer pattern recognition program.

关键词： O'-sialon-SiC compostites carbonthermal reduction-nitration pattern recognition program

Passivation Mechanism of 316L Stainless Steel in Oxidizing Acid Solution

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International Journal of Minerals,metallurgy and Materials 2000年第3期14卷 204-208页

作者： Xuanyi Wang, Yinshun Wu, Lin zhang, Baofeng Ding (Corrosion and Protection Centre, university of {2. and technology beijing, beijing 100083, china) Corrosion and Protection Centre University of Science and Technology Beijing Beijing 100083 China

The compositions and the chemical valence states of elements of 316L stainless steel passive film formed in the oxidizing acid solution were studied by X-ray Photoelectron Spectroscopic (XPS) analysis. The electrochemical polarization curve was measured. The passivation process in the oxidizing acid solution was studied by AC impedance technology. The results indicated that the stable compounds layer was formed on the surface of the sample and the adsorption was the main step in the nitrite solution during passivation process. The catalysis passivation mechanism was put forward according to the experimental results. During passivation process, the water molecule was adsorbed on the surface of the sample at first in the oxidizing acid solution. The oxidizer in the solution played a role as catalyst. The oxide and hydroxide, which could be changed each other and finally formed stable passive film, were generated from adsorbing intermediate under the catalytic action. The mathematical models for predicting the steady polarization curve and the AC impedance spectra at certain conditions have been obtained. The passivation mechanism of 316L stainless steel in the oxidizing acid solution can be interpreted by the catalysis passivation mechanism.

关键词： 316L stainless steel passive film XPS AC impedance spectra passivation mechanism

Three-Rigid-Body-Particle Modeling and Optimization of Trajectory and Posture for Alpine Skiing

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Journal of Systems science & Complexity 2024年第2期37卷 581-608页

作者： zhang Yijia FEI Qing YAO Xiaolan SUN jian zhang Yanjun CHEN Zhen school of Automation Beijing Institute of TechnologyBeijing 100081China

This paper presents a new study on modeling and optimization of trajectory and posture for the super-giant(SG)slalom of alpine *** is the first time that a Three-Rigid-Body-Particle model based on rigorous derivations and stability analysis is established to represent skiers trajectory and posture characteristics,as it is more accurate than the single-rigid-body model which is commonly used in existing *** addition,the Radau pseudospectral method is applied to solve the trajectory and posture optimization problem in order to obtain better skiing trajectory,skiing posture,and some key kinematic parameters of ***,this paper analyzes the effects of different body types,minimum turning radii,and flexor and extensor strength of knees and hip joint on skiing ***,based on the findings of the study,some advice about how to improve the performance of the SG slalom in view of science and technology is given to skiers and coaches for reference.

关键词： Alpine skiing modeling posture optimization Three-Rigid-Body-Particle model trajectory optimization

Data-Driven Active Disturbance Rejection Control of Plant-Protection Unmanned Ground Vehicle Prototype: A Fuzzy Indirect Iterative Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1892-1894页

作者： Tao Chen Ruiyuan Zhao jian Chen Zichao zhang College of Engineering China Agricultural UniversityBeijing 100083China Key Laboratory of Smart Agricultural technology in Tropical South china Ministry of Agriculture and Rural AffairsGuangzhou 510642China

Dear Editor,This letter proposes a fuzzy indirect iterative learning(FIIL)active disturbance rejection control(ADRC)scheme to address the impact of uncertain factors of plant-protection unmanned ground vehicle(UGV),in which ADRC is a data-driven model-free control algorithm that only relies on the input and output data of the *** on the established nonlinear time-varying dynamic model including dynamic load(medicine box),the FIIL technology is adopted to turn the bandwidth and control channel gain online,in which the fuzzy logic system is used to update the gain parameters of iterative learning in real *** and experiment show the FIIL-ADRC scheme has better control performance.

关键词： Active scheme iterative

Flow and Temperature Fields in Slab Continuous Casting Molds

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International Journal of Minerals,metallurgy and Materials 2000年第2期14卷 103-106页

作者： Yin zhang Liguo Cao Youduo He Shiqi Li Yishen Shen(Institute of Metallurgical Engineering, Baotou university of Iron & Steel {2. Baotou 014010, china)(metallurgy school, university of science and {2. beijing, beijing 100083, china) Baotou Univ Iron & Steel Technol Inst Met Engn Baotou 014010 Peoples R China Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China

In order to develop super-board and super-thick slabs, the flow and temperatur fields were studied in slab continuous casting molds under different practical conditions, such as slab dimensions, with-drawing slab speed, design of nozzles, and superheat tempera-ture. The results showed that it is preferred to incline nozzle bores downwards and the submerged depth of the nozzles is best kept be-tween 2.0-300 mm. In addition, the solidified shell is thicker at the wide face than that at the narrow face, while the thin points alongthe wide face ekist both in the center and in the some area toward each respective end.

关键词： slab continuous casting mold flow field temperature field mathematical model

Modeling and Optimizing of Deformed Steel Bars Hot Rolling

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International Journal of Minerals,metallurgy and Materials 1999年第4期13卷 289-291页

作者： Peng zhang Yunhui Du Xueping Ren(Material science and Engineering {2., university’ of science and technology’ beijing, beijing 100083) Material science and Engineering school University of Science and Technology Beijing Beijing 100083 China

Based on experimental data, a nonlinear model about tensile strength and technical parameters such as Mn and St content, finishing rolling speed and finishing rolling temperature for deformed steel bars in the process of hot rolling was established by using artificial neural networks. The model can be optimized with a genetic algorithm. The optimum rolling parameters were obtained.

关键词： artificial neural networks modeling genetic algorithm, optimizing

DISSOLUTION EQUILIBRIUM OF Mg VAPOUR IN LIQUID Fe

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Acta Metallurgica Sinica(English Letters) 1991年第9期4卷 230-233页

作者： zhang Xiaodong HAN Qiyong university of {2. and technology beijing,beijing,chinaCHEN Dong Hebei Institute of metallurgy,Shijiazhuang,china Univ of science and technology Beijing Beijing China

The dissolution equilibrium of magnesium vapour in liguid Fe has been studied in a two-tem- perature-zone furnace at 1600℃ by use of the vapour pressure *** equilibrium con- stant for the reaction Mg_(g)=[Mg] and the... 详细信息

关键词： liquid Fe Mg dissolution equilibrium