Z. Liu
,
Y. Y. Xu
,
Z.G. Wang
,
Y. Wang
,
and Z. Y. Liu State Key Laboratory for Fatigue and Fracture of Materials
,
Institute of Metal Research
,
Tile Chinese Academy of Sciences
,
Shenyang 110015
,
China School of Material Science and Engineering
,
Shenyang Technical University
,
Shenyang 110023
,
China
金属学报(英文版)
Fully reversed total strain-controlled low-cycle fatigue tests were conducted at room temperature in air to study fatigue behavior of AZ91HP in as high pressure die casting and subsequently heat treatments. All the specimens in different heat histories exhibited cyclic strum hardening in different degrees. It was difficult to distinguish the fatigue behaviors of the die-casting specimens from the solution-aging specimens. However the solution treated specimens showed longerfatigue life at high strum amplitude and shorter fatigue life at low strain amplitude than die-casting and the solution-aging specimens though they had the lowest yield strength with higher strain hardening. Fatigue fracture surfaces for strain amplitude larger than 0.005 showed very similar to those of the monotonic tensile tests. The SEM examination revealed that regions of fatigue crack growth and final fracture could be characterized by quasi-cleavage mech anisms, but some shallow dimples, slip bands and secondary cracks were found on the fracture surface in the fracturs crack growth areas.
关键词:
low-cycle fatigue
,
null
,
null
,
null
D.Q.Tang
,
Y. Wang
,
E.Y.Jiang
,
C.Zhao and F.L.Sun Department of Applied Physics
,
Tianjin University
,
Tianjin 300072
,
China
金属学报(英文版)
CN x films were made by a facing targets sputtering ( FTS) systemon the Si(100) substrate under different N 2 partial pressure. XRD, XPS, FTIR and Raman Spectroscopy( RS) were measured to investigate the structure and the binding state of the film. The films are amorphous and the N/C increases with the N 2 partial pressure increasing and reaches 0 46 when the N 2 pressure is 100%. The N incorporated C forms N sp 2C and N sp 3C mainly and there is a small amount of C≡N.
关键词:
Z.B. Shao
,
L.J. Zhang
,
Y. Wang
金属学报(英文版)
Peroviskite-type La1_xSrxMnO3 (0≤x≤0.3) was prepared through the solgel process at low temperature (1100℃). The ethylene glycol and citric acid were used to make a sol-gel from an aqueous solution of lanthanum strontium and manganese nitrates. The particle-diameter distribution of powders is from 10 to 50nm, the mean particle size is about 35nm and the specific surface area is about 92.5 to 98.5m2 g-1. Peroviskitetype La1_xSrxMnO3 was synthesized at 1100℃, and the electronic conductivity of La1-xSrxMnO3 is 104-105S.m-1 from room temperature to 1000℃.
关键词:
sol-gel
,
null
,
null
,
null
