GUO Jianting LI Hui SUN Chao ZHU Yaoxiao Institute of Metal Research
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Academia Sinica
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Shenyang
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China GUO Jianting
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Professor
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Institute of Metal Research
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Academia Sinica
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Shenyang 110015
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China
金属学报(英文版)
The microstructure and the mechanical properties from room temperature up to 1050℃ of Ni_3Al alloys containing 0—0.6 at.-%Zr,0—7.7 at.-%Cr and 0—2.22 at.-%B have been studied.It was found that the temperature dependence of their yield strength variation reveals to be anomalous,i.e.the strength increases with the temperature raising,and then decreases till it surpassed the peak value.Both Zr and Zr+Cr may improve the yield strength of the al- loys in the entire range of testing temperatures,as well as the tensile strength and elongation under high temperatures.B is favourable to raise the tensile and yield strengths of the alloys, and also plasticity.But the strength will reduce as B added is over 2.22 at.-%.The Ni_(20)Al_3B_6 and Ni_3Al eutectic mixture like islands and globes precipitated inside the grains and along the grain bounderies,which are harmful to the strength and ductility,may be formed when the B content exceeds the limit of solubility.
关键词:
Ni_3Al
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材料科学技术（英文）
A large quantity of laminated fine grain zones were observed in the Al-Mg-Li alloy weld metal by manual TIG, which was not found in ordinary Al alloy welds. The fine grain zone is formed because of the Al-3(Zr,Ti) particles in the filler metal and the manual filling of filler metal in welding process.
关键词:
MA Zongyi YAO Zhongkai Harbin Institute of Technology
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Harbin
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China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
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Corrosion
This paper introduces the design of a localized corrosion rate monitoring instrument that can monitor and evaluate the maximum and stable localized corrosion rate of a nonpassivable metal in a corrosive environment by measuring the current density in a corrosion sensor with an occluded anode.
关键词:
instrument;localized corrosion rate;monitor
Tomoki TSUMURA
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Michio INAGAKI
材料科学技术（英文）
Electrochemical insertion/extraction sf Li on cathode materials of anatase type TiO2, quasi-layered structure V2O5 and layered structure MoO3 was measured on samples of which structures were well characterized and showed a wide range of crystallinity. On the basis of experimental results on structure, morphology and charge-discharge characteristics, the effect of crystallinity of the cathode materials on electrochemical Li insertion/extraction performance was discussed. These three transition metal oxides were classified as one group on the basis of whether the crystallinity of these oxides affects to the performance or not, LiMn2O4 and LiCo0.5Ni0.5O2 belongs to the former group and TiO2, V2O5 and MoO3 to the latter.
关键词:
Juhua HUANG
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Jinjun RAO
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Xuefeng LI
材料科学技术（英文）
Sheet metal forming is widely applied to automobile, aviation, space flight, ship, instrument, and appliance industries. In this paper, based on analyzing the shortcoming of general finite element analysis (FEA), the conception of parametric finite element analysis (PFEA) is presented. The parametric finite element analysis, artificial neural networks (ANN) and genetic algorithm (GA) are combined to research thoroughly on the problems of process parameters optimization of sheet metal forming. The author programs the optimization scheme and applies it in a research of optimization problem of inside square hole flanging technological parameters. The optimization result coincides well with the result of experiment. The research shows that the optimization scheme offers a good new way in die design and sheet metal forming field.
关键词:
Sheet metal forming
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