SHAO Zhongbao
,
LIU Kuiren
,
MENG Bo
,
LI Ying
,
YANG Yuqing(Department of Chemistry
,
Northeastern University
,
Shenyang 110006
,
China) LIU Huakun
,
DOU Shixue(University of New South Wales
,
Kensington
,
Australia)
金属学报(英文版)
Phase equilibrium in the ternary CuO-PbO-Ag system has been investigated using differential thermal analysis(DTA),thermogravimetry(TG),scanning electron microscopy(SEM) and X-ray diffraction(XRD) techniques.In the ternary CuO-PbO-Ag system,there is a eutectic reaction CuO+PbO+Ag=L at 750℃ and a composition of 12.04 mol.% Ag,16.35 mol.% CuO and 71.61 mol.% PbO.Two miscibility gaps near the two binary tie lines PbO-Ag and CuO-Ag were detected. No binary or ternary compound was detected in the ternary system.SEM and energy dispersive spectroscopy(EDS) confirm the presence of two liquid phases and the eutectic point.
关键词:
:phase equilibrium
,
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,
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,
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,
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WU Zhixue
,
XU Hao(Institute of Mechanical Engineering
,
Northeastern University
,
Shenyang 110006
,
China)(Fushun Petroleum institute
,
Fushun 113001.China).(State Key Laboratory for Fatigue and Fracture of Materials
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China) Manuscript received 2 July 1995
金属学报(英文版)
Rotary bending fatigue tests were carried out using smooth specimens of a medium-carbon steel with two different grain sizes.The process of early crack development was observed by the replica method,and the effects of grain size and microstructure on short crack development were studied.It was shown that the initiation process of fatigue cracks is that the damaged region is intensified gradually,and the growth of short cracks relates to the coalescence of cracks.The grain size and microstructure have a great influence upon the initiation and growth of short cracks.A reasonable definition was given in relation to short fatigue crack initiation and propagation.
关键词:
:fatigue damage
,
null
,
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,
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Ke LU National Key Laboratory for RSA
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
ChinaManling SUI Department of Materials Science and Engineering
,
Northeastern University
,
Shenyang 110006
,
China
材料科学技术（英文）
A thermodynamic analysis of the ultrafine crystallites in nanocrystalline materials was presented in this work.It was deduced that the structure of the nm-sized crystalline grains is different from the perfect crystal lattice,characterized by two possible structure changes;supersaturation of alloy ele- ments and crystal lattice distortion resulted from supersaturation of vacancies.Some experimental ev- idences in the literature,which are in agreement of the thermodynamic consideration,indicate that the structure changes in the nm-sized crystallite seems to be a consequential feature of the nanocrystalline materials.
关键词:
nanocrystalline materials
,
null
,
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SONG Dan
,
DING Jinjun
,
WANG Yandong(Analysis and Testing Center
,
Northeastern University
,
Shenyang 110006
,
China)
金属学报(英文版)
The microstructures of Ti-14Al-21Nb and Ti-14Al-20Nb-2Mo-3.2V(wt%) alloys have been investikated by transmission electron microscopy(TEM).The phase constitution and the orientation relationship between α2and βwere identified by means of the selected area diffraction and the micro-diffraction techniques.Results show that,compared to Ti-14Al-21Nb,the alloying elements Mo and V can greatly increase the fraction of β phase and improve significantly the microstructures of Ti-14Al-20Nb-2Mo-3.2V.The ordered B2 structure is also evident in the residual βgrains of the latter alloy.
关键词:
:microstructure
,
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,
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