Nanostructured Ti29.7Ni50.3Hf20 high temperature shape memory alloy processed by high-pressure torsion
Nanostructured Ti29.7Ni50.3Hf20 high temperature shape memory alloy processed by high-pressure torsion
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高压扭转加工纳米结构Ti29.7Ni50.3Hf20高温形状记忆合金
DOI：
10.1016/j.jmst.2020.01.065
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发表时间：
2020-09-01
影响因子：
10.9
通讯作者：
Tong, Y. X.
中科院分区：
文献类型：
--
作者：
Shuitcev, A.;Gunderov, D., V;Tong, Y. X.
对 Ti29.7Ni50.3Hf20 (at.%) 合金进行 6.0 GPa 压力下的高压扭转 (HPT) 加工。 HPT 3转后观察到两种类型的结构：第一种是非晶相和保留的纳米晶的混合物；第二是非晶相和高缺陷密度结晶相的交替带。结果，500-700℃的变形后退火（PDA）导致马氏体和母相晶粒分布不均匀。马氏体晶粒比母相大两倍。分别在 500-600 摄氏度和 700 摄氏度退火后形成纳米晶和超细晶粒。孪晶机制不会随着马氏体晶粒减小至 35 nm 左右而改变。 Ti29.7Ni50.3Hf20 合金的强度和晶粒尺寸之间的关系遵循经典的 Hall-Petch 关系，系数为 10.80 +/- 0.39 GPa nm(1/2)。 (C) 2020 由Elsevier Ltd 代表Journal of Materials Science & Technology 编辑部出版。
High pressure torsion (HPT) processing under a pressure of 6.0 GPa was applied to Ti29.7Ni50.3Hf20 (at.%) alloy. Two types of structure were observed after HPT with 3 revolutions: first one is the mixture of amorphous phase and retained nanocrystalline; second is the alternating bands of amorphous phase and high defect density crystalline. As a result, post deformation annealing (PDA) at 500-700 degrees C leads to the non-uniform distribution of martensite and parent phase grains. The grains of martensite are twice larger compared to that of parent phase. The nanocrystalline and ultrafine grains form after annealing at 500-600 degrees C and 700 degrees C, respectively. The twinning mechanism does not change with the reduction of martensitic grains up to similar to 35 nm. The relationship between strength and grain size in Ti29.7Ni50.3Hf20 alloy obeys the classical Hall-Petch relationship with a coefficient of 10.80 +/- 0.39 GPa nm(1/2). (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.