In-situ synchrotron high energy X-ray diffraction study of spontaneous reorientation of R phase upon cooling in nanocrystalline Ti_(50)Ni_(45.5)Fe_(4.5)alloy  

作　　者：Zhi-Yuan Ma Yu-Xuan Chen Yang Ren Kai-Yuan Yu Da-Qiang Jiang Yi-Nong Liu Li-Shan Cui 

机构地区：[1]Department of Materials Science and Engineering,China University of Petroleum(Beijing),Beijing 102249,China [2]Department of Physics,City University of Hong Kong,Hong Kong 999077,China [3]Centre for Neutron Scattering,City University of Hong Kong,Hong Kong 999077,China [4]Department of Mechanical Engineering,The University of Western Australia,Perth,WA 6009,Australia

出　　处：《Rare Metals》2022年第6期1948-1954,共7页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos.51731010, 51831006,51871241,51971243 and 91963112);Australian Research Council (No.DP190102990)

摘　　要：This study investigated a peculiar phenomenon of self-reorientation of thermally formed R phase in nanocrystalline Ti_(50)Ni_(45.5)Fe_(4.5)by means of in-situ syn-chrotron high energy X-ray diffraction(HE-XRD).Two samples with different average grain sizes of 40 and 90 nm were investigated.R phase in the 40-nm grain size sample was found to self-reorient gradually upon cooling,whereas the same phenomenon did not occur in the 90-nm grain size sample.This self-reorientation process is attributed to the development and evolution of an internal stress anisotropy caused by the second order continuous lattice distortion of R phase upon further cooling in the small nanograined matrix,which lacks the self-accommodation mechanism for internal stress cancellation.

关 键 词：TiNiFe Martensitic transformation R phase reorientation Synchrotron diffraction Nanocrystalline material 

分 类 号：TG139.6[一般工业技术—材料科学与工程]