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Journal of materials Science & Technology 2010年第10期26卷 865-871页

作者： Yue Yang and Hua Wu key laboratory of advanced structural materials,Ministry of Education,Changchun University of Technology,Changchun 130012,china key laboratory of advanced structural materials Ministry of Education Changchun University of Technology

To improve the surface wear resistance of the ceramic coating fabricated by micro-arc oxidation （MAO） on AZ91D magnesium alloy,ceramic coatings embedded with SiC nano-particles at different current frequency （500 Hz,700 Hz,and 900 Hz） were produced during the MAO *** morphology and phase composition of the coatings were investigated by scanning electron microscopy （SEM）,field emission scanning electron microscopy （FESEM）,and X-ray diffraction （XrD）.The surface roughness of the coatings was characterized by confocal laser scanning microscopy （CLSM）.Simultaneously,the tribological properties of the composite coatings were evaluated by using a universal materials tester （UMT）.The results shows that the wear resistance of the ceramic coatings with SiC nano-particles was improved significantly compared to the ceramic coatings without SiC ***,the composite coating formed at current frequency 900 Hz showed the better wear resistance than the others.

关键词： Magnesium alloy Micro-arc oxidation SiC nano-particles Wear resistance

Solidification Simulation of Investment Castings of Single Crystal Hollow Turbine Blade

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Journal of materials Science & Technology 2003年第6期19卷 532-534页

作者： Jiarong LI, Shizhong LIU, Hailong YUAN and Zhengang ZHONGNational key laboratory of advanced High Temperature structural materials, Beijing Institute of Aeronautical materials, Beijing 100095, china Lab. of Adv. High Temp. Mat. Beijing Inst. of Aero. Mat. Beijing 100095 China

The three-dimensional solidification simulation of the investment castings of single crystal hollow turbine blade at the withdrawal rates of 2 mm/min, 4.5 mm/min and 7 mm/min has been performed with the finite element thermal analysis. The calculated results are in accordance with the experimental ones. The results show that with the increase of withdrawal rate the concave curvature of the liquidus isotherm is larger and larger, and the temperature gradients of the blades increase. No effects of withdrawal rate on the distribution of the temperature gradients of the starter and helical grain selector of the blades are observed at withdrawal rates of 2 mm/min, 4.5 mm/min and 7 mm/min. The relatively high temperature gradient between 500℃/cm and 1000℃/cm in the starter and helical grain selector is obtained at three withdrawal rates.

关键词： Single crystal Hollow turbine blade Solidification simulation

The Micro/Nanostructure Characteristics and the Mechanical properties of Hemifusus tuba Conch Shell

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Journal of Bionic Engineering 2010年第4期7卷 3+308-313页

作者： Yan Liang~1,Jie Zhao~2,Chengwei Wu~1 1.State key laboratory of structural Analysis for Industrial Equipment,Department of Engineering Mechanics,Dalian University of Technology,Dalian 116024,p.r.china 2.School of materials Science and Engineering,Dalian University of Technology,Dalian 116024,p.r.china State key laboratory of structural Analysis for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology Dalian P. R. China School of materials Science and Engineering Dalian University of Technology Dalian P. R. China

The mollusk shell mobilizes calcium from environment for skeletal *** occurs through synthesizing solidsin solution in the presence of organic molecules of specific interior regions of the conch *** ultrastructure and microhardnessof the Hemifusus tuba conch shell living in the Huang/Bo sea area are investigated in the *** is shown that thecomposition and microstructure of the mollusk shell vary in different *** prodissoconch shell consists only of aragonitewith the crossed-lamellar *** the spiral shell and the body shell of the Hemifusus tuba conch shell arecomposed of one calcite layer and several aragonite *** calcite layer consists of cylindrical grains,but the aragonitelayers are crossed-lamellar ultrastructure at three size *** minimum structure size (the third-order lamella) is at about20 nm - 80 *** margin of shell aperture is only composed of calcite with cylindrical *** natural optimization of theshell microstructure is intimately due to the growth of the Organic *** different positions the microhardness of molluscshell is different due to different crystal structures and crystal *** growth process of shells allows a constantrenewal of the material,thus enabling their functional adaptation to external environments.

关键词： conch shell microstructure aragonite calcite crossed-lamellar

Controlling uncertain fuzzy neutral dynamic systems with Markov jumps

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Journal of Systems Engineering and Electronics 2010年第3期21卷 476-484页

作者： Shuping He1,2 and Fei Liu1,2,1.key laboratory of advanced process Control for Light Industry,Ministry of Education,Jiangnan University,Wuxi 214122,p.r.china 2.Institute of Automation,Jiangnan University,Wuxi 214122,p.r.china key laboratory of advanced process Control for Light Industry Ministry of Education Jiangnan University Wuxi 214122 P. R. China Institute of Automation Jiangnan University Wuxi 214122 P. R. China

The robust H∞ control problems for stochastic fuzzy neutral Markov jump systems（MJSs） with parameters uncertainties and multiple time-delays are *** delays are respectively considered as constant and time varying,and the uncertain parameters are assumed to be norm *** means of Takagi-Sugeno fuzzy models,the overall closed-loop fuzzy dynamics are constructed through selected membership *** selecting the appropriate Lyapunov-Krasovskii functions,the sufficient condition is given such that the uncertain fuzzy neutral MJSs are stochastically stability for all admissible uncertainties and satisfies the given H∞ control *** stability and H∞ control criteria are formulated in the form of linear matrix inequalities,which can be easily checked in *** examples illustrate the effectiveness of the developed techniques.

关键词： neutral Markov jump system(MJS) Takagi-Sugeno fuzzy model time-delay uncertainty linear matrix inequality(LMI).

Crystallization behavior of Zr_(52) Cu_(18) Ni_(15) Al_(10) Ti_5 bulk glass with quenched-in crystals

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中国有色金属学会会刊：英文版 2000年第3期10卷 345-348页

作者： BIAN Zhan(边赞), HE Guo(何国), CHEN Guo liang(陈国良) State key laboratory of advanced Metals and materials, University of Science and Technology Beijing, Beijing 100083, p.r.china Univ. of Sci. and Technol. Beijing Beijing 100083 China

Zr 52 Cu 18 Ni 15 Al 10 Ti 5 bulk glass samples with a diameter of 8 mm prepared by copper mold with water cooling have a mixing structure of amorphous phase and quenched in crystals. By isothermal annealing at different temperatures, the crystallization process of the glass alloy is shown to be a multi staged crystallization reaction as follows: Am+quenched in crystals→Am′+cellular phase+(Zr, Ti) Al→Am′+cellular phase+(Zr, Ti) Al+(Zr, Ti) 2(Cu, Ni). Morphology of the quenched in crystals changes from dot or dendritic phase in the as cast bulk glass to cellular phase at different annealing states. The residual region surrounded by the cellular phase has a mixing structure of nano scale phase and amorphous phase.

关键词： bulk glass quenched in crystals crystallization nano scale phases

A Study of Mechanical properties of the Iron-base Sintered Steel Adding Fine Cr-Fe powder

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稀有金属材料与工程 2011年第S3期40卷 5-8页

作者： Chen Hua 1 , Liu Yongbing 2 , Li Yueying 2 , Cao Zhanyi 2 , Chai Zhilong 3 1 key laboratory of advanced structural materials, Ministry of Education, Changchun University of Technology, Changchun 130012, china 2 key laboratory of Automobile materials, Ministry of Education, Jilin University, Changchun 130022,china 3 research Institute of First Automobile Factory of china, Changchun 130011, china Changchun Univ Technol Sch Mat Sci & Engn Key Lab Adv Struct Mat Minist Educ Changchun 130012 Peoples R China Jilin Univ Key Lab Automobile Mat Minist Educ Changchun 130022 Peoples R China res Inst First Automobile Factory china Changchun 130011 Peoples R China

This paper reports an investigation of the mechanical properties and the fracture mechanism of iron-based sintered alloy containing fine Cr-Fe powder particles 300 nm in size and in contents raging from 0.2-1.5 wt%. The iron-base alloy were sintered at 1120 ℃ for 40min. The results of the study revealed improvement in mechanical properties such as tensile strength, elongation and hardness of the sintered alloy. The fracture behaviors of the alloy were influenced significantly by the presence of Cr-Fe powder particles. The mechanical properties increased with increasing Cr content. Micrographs of fracture appeared dimple and quasi-cleavage.

关键词： sintered steel fine Cr-Fe powder mechanical properties

Effect of Thermal Fatigue Loading on Tensile Behavior of H13 Die Steel with Biomimetic Surface

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Journal of Bionic Engineering 2010年第4期7卷 390-396页

作者： Zhihui Zhang~1,Luquan ren~1,Hong Zhou~2,Zhiwu Han~1,Xin Tong~3,Yu Zhao~1,Li Chen~1 1.key laboratory of Bionic Engineering (Ministry of Education,china),Jilin University,Changchun 130022,p.r.china 2.key laboratory of Automobile materials (Ministry of Education,china),Jilin University,Changchun 130022,p.r.china 3.The Department of materials Surface Engineering,Guangzhou research Institute of Non-Ferrous Metals,Guangzhou 510651,p.r.china key laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun P. R. China key laboratory of Automobile materials (Ministry of Education China) Jilin University Changchun P. R. China The Department of materials Surface Engineering Guangzhou Research Institute of Non-Ferrous Metals Guangzhou P. R. China

Biomimetic surface is an effective ways to promote the performance grade and applied range of materials without alteringtheir *** improved properties such as resisting fatigue,enduring wear,etc,have been achieved by applyingbiomimetic morphology or structure to some engineering material *** this paper,aiming to reveal the relationshipbetween thermal cracking behavior and mechanical properties of engineering materials with biomimetic surface,biomimeticspecimens were fabricated using laser technique by imitating the heterogeneous structure on the surface of plant *** of thermal fatigue cycling on the tensile properties of H13 die steel specimens with different surfaces (several types ofbiomimetic surfaces and a smooth surface) was compared and *** a result,due to the coupling effects of themorphological features on the surface and the microstructure characteristics within unit zone,these specimens with biomimeticsurface exhibit remarkably enhanced Ultimate Tensile Strength (UTS) and 0.2% Yield Strength (YS) compared with referencespecimens while corresponding ductility remains largely unaffected even heightened,whether the thermal fatigue loads or *** relative mechanisms leading to these improvements have been discussed.

关键词： biomimetic surface coupling thermal fatigue tensile property H13 steel

A Creep Equation Based on Thermal Activation

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International Journal of Minerals,Metallurgy and materials 1998年第1期12卷 44-46页

作者： Jiyue Sun Guoliang Chen (State key laboratory for advanced Metals and materials, University of Science and Technology Beijing, Beijing 100083, china) State key laboratory for advanced Metals and materials University of Science and Technology Beijing Beijing 100083 China

The creep equation proposed in so called θ projection concept is developed in the concept of thermal activation of creep. The measured creep curves of A286 alloy are fitted by the equation. The activation energy in theequation is evaluated, and creep rupture lives are predicted. The results are confirmed by creep tests of up to 13years.

关键词： creep creep curve equation creep rupture life A286 superalloy

TTT Diagram Used to Control phase Structure of 2/4 Functional Epoxy Blends for advanced Composites

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Chinese Journal of Aeronautics 2009年第4期22卷 449-452页

作者： Zhang Ming,An Xuefeng,Tang Bangming,Yi Xiaosu National key laboratory of advanced Composites materials,Beijing Institute of Aeronautical materials,Beijing,100095,china National key laboratory of advanced Composites materials Beijing Institute of Aeronautical Materials Beijing 100095 China

This article uses a 2/4 functional epoxy blend system （E-54/AG-80） cured with diaminodiphenyl sulphone（DDS） as a raw material and develops a methodological procedure to establish a cure kinetic model with isothermal and dynamic differential scanning calorimeter（DSC） method and a gelation model with round-disk compression mode dynamic mechanical analyzer（DMA）, thus acquiring a series of experimental data. Characteristic temperatures such as initial glass transition temperature Tg0, gelation glass transition temperature gelTg, and infinite glass transition temperature Tg∞ are determined. The cure degree at gelation is turned out to be 0.45, while ge1Tg is found to be 70.2 ℃. The data are then used to form time-temperature-transition（TTT） diagram of the system, which serves to be a tool for process optimization of epoxy-matrix composites. A new cure processing is therefore derived from the TTT diagram. The final phase structure obtained from a controllable method is identified through scanning electron microscope（SEM） photographs to be of＂ex-situ＂ phase morphology.

关键词： composites epoxy resins TTT diagram phase structure