LIU Senying GAO Zhe LI Keng University of Science and Technology Beijing
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ChinaLI Junqing China University of Science and Technology
,
Hefei
,
ChinaWANG Congyu Central Iron and Steel Research Institute
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Ministry of Metallurgical Industry
,
Beijing
,
China Doctoral student
,
Postgraduate School
,
Cemral Iron and Steel Research Institute.Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
Based on the feature of crystal sites occupied by alloying elements,a model cluster,investi- gating the interaction mechanisms of nonmagnetic element Cu in RECo_5 type alloy,has been presented.The electronic structure has been calculated with SCF-X_a-SW method.The calcu- lating results show that,after Cu replaced 2c crystal site Co,the energy spectrum of the mod- el cluster will move towards a shallow trap po.tential,the energy gap becomes small,the charge among the atoms will redistribute,and some new states to which impurity contributes will pro- duce.Partial-wave local density of states gives the interaction between atoms.Results of Hellmman-Feynman force show that the thermal expansion anisotropy of the model cluster decreases considerably after Cu substitutes for 2c crystal site Co.
关键词:
intermetallic compound
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QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
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null
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null
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