Jinghua YIN
,
Meicheng LI
,
Yufeng ZHENG
,
Zhong WANG
,
Wei CAI
,
Peilin WANG
,
Peilin WANG
材料科学技术（英）
The effect of annealing temperature on the formation of the PtSi phase. distribution of silicides and the surface morphologies of silicides films is investigated by XPS. AFM. It is shown that the phase sequences of the films change from Pt-Pt2Si-PtSi-Si to Pt+Pt2Si+PtSi-PtSi-Si or Pt+Pt2Si+PtSi-PtSi-st with an increase of annealing temperature and the reason for the formation of mixed layers is discussed.
关键词:
Xin GAO
,
Yufeng ZHENG
,
Wei CAI
,
Su ZHANG
,
Liancheng ZHAO
材料科学技术（英）
The microstructure, phase transformation, compression property and strain recovery characteristics of equiatomic TaRu super high temperature shape memory alloy have been studied by optical microscope, XRD, DTA, compression tests and TEM observations. When cooling the alloy specimen from high temperature to the room temperature, (parent phase)→ (interphase)→ (martensite) two-step phase transformations occur. The microstructure at room temperature show regularly arranged band morphology, with the monoclinic crystal structure. The twinning relationship between the martensite bands is determined to be (101) of Type I. Reorientation and coalescence of the martensite bands inside the variant happened during compression at room temperature. The → reversible transformation contributes mainly the shape memory effect, with the maximum completely recovery strain of 2%.
关键词:
TaRu alloy
,
null
,
null
,
null
Jianxin ZHANG
,
Yufeng ZHENG
,
Wei CAI and Liancheng ZHAO (School of Materials Science and Engineering
,
Harbin Institute of Technology Harbin
,
150001
,
China)
材料科学技术（英）
Detailed crystallographic analysis has been undertaken on the various combinations Of 24 martensite variants in the 18R martensite of a Cu-Zn-Al shape memory alloy. Based upon the calculated crystallographic data, the interface energy of different twin interfaces was calculated using a lowangle-grain-interface model. For the variant/variant pairs in a self-accommodating group. the A/C type and A/B type interfaces have low interface energy, and A/D type interface is an intermediate one. In contrast, the intervariant interfaces that belong to different plate groups have high intrface energy. The calculated results are consiStent with the previous observations of the mobility of intervariant interfaces.
关键词:
Liming WANG
,
Yufeng ZHENG
,
Wei CAI
,
Xianglong MENG
,
Liancheng ZHAO
材料科学技术（英）
The effect of thermal cycling under loading on martensitic transformation and two-way shape memory effect was investigated for Ti-49.8 at, pet Ni alloy. It is shown that M-s, and M-f temperature increase with increasing the number of cycles, while A(s) and A(f) temperature decrease during thermal cycling. The total strain at and permanent strain epsilon (p) increase with increasing applied stress and number of cycles. The two-way shape memory effect can be improved by proper thermal cycling training under loading, while excessively high applied stress results in the deterioration of TWSME. The reason for the changes in martensitic transformation characteristics and two-way shape memory effect during thermal cycling under loading is discussed based on the analysis of microstructure by TEM observations.
关键词:
