Mechanisms of two-stage martensitic transformation in Ti-Ni-Hf alloy powder

Progress in Natural Science: Materials International

Kuishan Sun¹  Zhongli Liu²  Xiaoyang Yi²  Xinxin Feng²  Zhiyong Gao²  Haizhen Wang³  Xianglong Meng³ 

[1] Corresponding authors.;College of Nuclear Equipment and Nuclear Engineering, Yantai University, Yantai 264005, China;School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;

关键词: Ti-Ni-Hf alloy Powders;    Shape memory shape;    PREP;    Martensitic transformation;    Microstructure;   

DOI  :  

来源: DOAJ

【 摘 要 】

The Ti-Ni-Hf shape memory alloy powders were prepared by plasma rotating electrode process. And the powders were featured with the perfect sphericity and smooth surface. Moreover, the grain size was refined in the Ti-Ni-Hf alloy powders due to the rapid cooling rate during plasma rotating electrode process. It was found that the Ti-Ni-Hf alloy powders had the typical self-accommodation configuration including spear-like, mosaic-like and lath-like martensite. Various twins, such as (001) compound twin, (011) type I twin as well as {111} type I twin, were observed in Ti-Ni-Hf alloy powders. Differing from the bulk Ti-Ni-Hf alloy, two-stage transformation corresponding to B2⇌B19’ martensitic transformation was detected in the as-received Ti-Ni-Hf alloy powders. In addition, the martensitic transformation behaviors were closely related to the annealing temperatures. The Ti-Ni-Hf alloy powders with low annealing temperature of 500 ​°C still exhibited two-stage martensitic transformation, while two-stage martensitic transformation changed into single martensitic transformation in the Ti-Ni-Hf alloy powders with the higher annealing temperature of 900 ​°C. And finally the possible mechanisms for the evolution of martensitic transformation behaviors were discussed.

【 授权许可】

Unknown