YAN Yuhe YANG Yongqiang ZHAO Changming Tianjin Institute of Textile Science and Technology
,
Tianjin
,
ChinaWU Weitao WANG Maocai Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
ChinaLU Mengfu Tianjin Institute of Science and Technology
,
Tianjin
,
China Lecturer
,
Laser Processing Lab.
,
Tianjin Institute of Textile Science and Technology
,
Tianjin 300160
,
China
金属学报(英文版)
Partially amorphous Ni-Nb alloy was made by 1.91 kW cw CO_2 laser melt-quenching, and fully amorphous by 4.5 kW and 4.9 kW.The corrosion resistance of the amor- phous layer was improved by adding Cr.Potentiodynamic polarization curves show that the amorphous Ni_(50)Nb_(40)Cr_(10) is in more corrosion-resistant than the amorphous Ni_(60)Nb_(40)and 18-8 stainless steel.
关键词:
Ni-Nb allay
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null
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null
LUO Laizhong ZHANG Jinxiu LIN Guangming Zhongshan University
,
Guangzhou
,
510275
,
China Lecturer
,
Dept.of Physics and Institute of Material Science
,
Zhongshan University
,
Guangzhou
,
510275
,
China
金属学报(英文版)
The snap-action behavior of a Ni-Ti alloy disc which is controlled by combination of a nonlinear stress field and temperature has been studied.After treatment for two-way shape memory,all shape memory strain of snap-action finishes abruptly at a certain temperature within an interval of less than 1 ms.The results of resistance measurement and in-situ X-ray diffraction indicate that the snap-action strain is mainly resulted from the snap-action β (?)R transformation.
关键词:
shape memory alloy
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null
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null
WANG Mingpu
,
LIU Jinwen Central South University of Technology
,
Changsha
,
China Lecturer
,
Dept.of Materials Science and Engineering
,
Central South University of Technology
,
Changsha 410083
,
China
金属学报(英文版)
The stabilization of thermoelastic martensite in a rapidly solidified Cu-Zn-A1 alloy is be- lieved to be the process of disordering in atomic configuration during which the structure of martensite gradually transforms into N9R(b/a=1/3~(1/2))from M18R.This is dependent upon the intrinsic decomposition tendency of the martensite.
关键词:
Cu-Zn-Al alloy
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null
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null
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null
CHEN Wenzhe QIAN Kuangwu FuZhou University
,
Fuzhou
,
Fujian
,
China Lecturer
,
Dept.of Mechanical Engineering
,
Fuzhou University
,
Fuzhou
,
Fujian
,
China
金属学报(英文版)
The effect of various dynamic strain aging(DSA)pre-treatment processes on pure bending fatigue strength of an 18-8 austenitic stainless steel was investigated.The results show that DSA pre-treatment processes increase remarkably the fatigue strength and the strengthening effects increase with increasing pre-strain temperature and pre-strain.The fatigue limit of specimens pre-treated by DSA is 87% higher than that by solution treatment,and 20% high- er than that by cold-working.TEM observations show that the uniform and stable dislocation networks with high density formed after DSA pre-treatment,which suppress effectively the initiation and propugation of fatigue cracks and increase the fatigue strength of materials.
关键词:
dynamic strain aging(DSA)
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null
,
null
LU Xiaoye Central south University of Technology
,
Changsha
,
China Lecturer
,
Dept.of Materials Science and Engineering
,
Central South University of Technology
,
Changsha 410083
,
China
金属学报(英文版)
The stability of thermoelastic martensite in a Cu-14.84 wt-%Zn-7.75 wt-%Al shape mem- ory alloy with M_s=106°C after direct quenching or stepped quenching has been investigated by using TEM,X-ray diffroctometer and double electric bridge instrument.The martensite aged for about 3 h at room temperature after either direct quenching or stepped quenching (150°C,2 rain)is the M18R structure.The martensite just directly quenched is not so stable, both its certain diffraction peaks and specific electric resistivity,change with aging at room temperature;whereas it is stable after stepped quenching(150°C.2 min),and its diffraction peaks and specific electric resistivity change no more with aging at room temperature.The above mentioned results seem to be explained by the martensite reordering.
关键词:
Cu-Zn-Al alloy
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null
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null
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null
GAO Weilin.BAI Guangrun
,
ZHOU Zhimin
,
LUAN Guifu Northeast University of Technology.Shenyang
,
ChinaLONG Chunman Anshan Iron and Steel Company
,
China Lecturer
,
Post Box No.92.Northeast University of Technology.Shenyang 110006
,
China
金属学报(英文版)
Experimental investigation of hot deformation behaviour of Nb-bearing low carbon steel 14MnNb was carried out by Gleeble 1500 simulator.Regressive analysis was made of the re- lationship between deformation onditions and steady state flow stress during hot deformation and the peak fliw stress corresponding to dynamic recrystallization.Clarification was also described for the influence of strain-induced Nb(C.N)precipitation on the activation energy of deformation.On the basis of analyzing the processes of dislocation multiplication and re- coveries from cross-slip of screw dislocation and from climb of edge dislocation during plastic deformation of metals.the theoretical mpdel to predict flow stress under the condiltions of dy- namic recorery and recrystallization occirred simultancously was developed,The prediction about flow stress in practice,under various deformation conditions by the model seems in fair agreement with the experimental results.
关键词:
flow stress
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null
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null
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null
LIANG Sizu LIANG Yaoneng LIU Zhengyi South China University of Technology
,
Guangzhou
,
China Lecturer
,
Department of Mechanical Engineering No.2
,
South China University of Technology
,
Guangzhou 510641
,
China
金属学报(英文版)
The fracture surface of the normalized steel 55SiMnMo was observed,under tensile device at- tached on the SEM,to be of ductile dimple feature on the bainite which is composed of lath ferrite and austenite platelet.The dimple is essentially nucleated in the ferrite.Because the austenitic plastic deformation is remarkable during fracturing,the tear ridge of dimple is very sharp.
关键词:
dimple
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null
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null
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