Author C.D. Zhou1
,
2)
,
J.X. Yu1)
,
X.P. Dong1)
,
Y.H. Zhang1)
,
C.Q. Sun3) and T.F. Li4) 1) The State Education Commission Open Research Laboratory for High Temperature Materials and Testing
,
Shanghai Jiao Tong University
,
Shanghai 200030
,
China2) Shanghai Enhanced Lab of Ferrometallurgy
,
Shanghai University
,
Shanghai 200072
,
China3) Institute of Aeronautical Materials
,
Beijing 100095
,
China 4) Institute of Corrosion and Protection of Metals
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
An investigation has been made on the tensile fracture behavior of oriented single crystal DD100 superalloy at 850. The appearance of the fracture surface of DD100 reflects the glide plane decohension fracture mechanism, which is different from the fracture of oriented DD100. The tensile strength and elongation are lower than the oriented DD100. Oxygen in air has little effect on the strength of DD100 but reduces the tensile elongation obviously. Oxygen does not affect the fracture mode of DD100 but strongly accelerates the process of fracture.
关键词:
single crystal superalloy
,
null
,
null
Author H.J. Shi1)
,
S.L. Liu2)
,
Y.H. He1) and Z.X. Duan2) 1) Department of Engineering Mechanics
,
Tsinghua University
,
Beijing 100084
,
China2) Laboratory of Material Mechanical Properties
,
Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
A series of low cycle fatigue and creepfatigue tests on smooth specimens and notched specimens were performed with a high temperature alloy used in the manufacture of aeroengine turbine discs. The cyclic stressstrain behavior and fracture characteristics of the notched specimens were emphatically investigated. A comparison of fatigue behavior between smooth and notched specimens was done and lifetime of notched specimens was evaluated. At the same temperature, the fatiguecreep lives of the smooth specimens are far greater than that of the notched specimens.
关键词:
low cycle fatigue
,
null
,
null
,
null
Author S.T. TU
,
J.M. Gong and X. Ling Nanjing University of Chemical Technology
,
Nanjing 210009
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
In order to interpret the test results of crossweld specimens for application in practical welded components, the present paper studies the high temperature behavior of laboratory cross weld specimens in terms of the uniaxial material tests and numerical simulations. It is found that the crossweld specimen may be used for the high temperature strength assessment, but can hardly be used for life assessment of the practical welded components, which depends on the loading conditions of the components.
关键词:
high temperature
,
null
,
null
,
null
,
null
Author N. Wang
,
B.S. Zhou
,
Z.D. Wang and D.D. Wu College of Mechanical Engineering
,
East China University of Science and Technology
,
Shanghai 200237
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
Based on the fundamental definition of damage and inelastic strain energy hypothesis, this paper presents an inelastic strain energy damage model under creepfatigue interaction condition, with the damage constitutional equations and life prediction formulae respectively described by strain and stress. Creepfatigue tests with notchedbar specimens were carried out at 550. The actual creepfatigue lives are in good agreement to the predicted lives according to inelastic strain energy damage model.
关键词:
damage mechanics
,
null
,
null
,
null
Author S.R. Zhou
,
S.R. Qiao
,
S.H. Bai and C.S. Tian Faculty 401
,
Northwestern Polytechnical University
,
Xian 710072
,
ChinaManuscript received 18 October 1998
金属学报(英文版)
The tensile properties of three different carbonfiberreinforced carbon composites (C/C), mat C/C, 2D laminate and 4D C/C, were investigated under the combined influence of temperature and loading rate. From the experiments the following could be concluded: loading rate between 10-1-10 mm/min was valid; the fracture stress of the three kinds of C/C composites increased with increasing temperature in the range from room temperature to 1900, and the initial modulus of 2D laminate C/C composites increased with the increase of temperature up to 2000.
关键词:
tensile testing
,
null
,
null
,
null
Author X.A. Zhang1)
,
H.Q. Xia1)
,
Z.T. Wu1)
,
Y.F. Han1)
,
R. Shi2) and G.X. Hu2) \= 1) Mechanical Properties Laboratory
,
Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
China2) The State Education Commission Open Research Laboratory for High Temperature
金属学报(英文版)
Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, ChinaManuscript received 18 October 1998 The threestage creep behavior of DD3 single crystal superalloy had been studied. The results show that the creeprupture properties of DD3 single crystal satisfy the requirements for high performance turbine blade application. The influence of crystal orientation on the creeprupture property of DD3 single crystal was tested and discussed. An engineering criterion to evaluate the regimes of secondary and tertiary creep is proposed, and this method gives a reasonable result for practical applications. The fractography and TEM micrography of the tested specimens had been studied, and it is determined that the glidecontrolled creep is the basic creep mechanism of DD3 single crystal at intermediate temperature, but the thermally activated processes become dominant at higher temperature.
关键词:
threestage creep curve
,
null
,
null
,
null
李国栋
稀有金属材料与工程
综述了1997年～1998年间若干磁性功能材料在研究和应用方面的若干新进展.这些新进展包括:(1)非晶和纳米晶软磁材料;(2)新的磁效应与新的磁性功能材料;(3)磁共振成象在显示生物活体电性等上的应用;(4)磁力显微镜的新应用;(5)磁浮火车从研究、试验和走向应用.
关键词:
软磁材料
,
新的磁效应
,
磁共振成象
,
磁力显微镜
,
磁浮火车
