Crystallization process and shape memory properties of Ti–Ni–Zr thin films
Crystallization process and shape memory properties of Ti–Ni–Zr thin films
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DOI：
10.1016/j.actamat.2008.12.036
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发表时间：
2009-04
期刊：
影响因子：
9.4
通讯作者：
H. Y. Kim;M. Mizutani;S. Miyazaki
中科院分区：
文献类型：
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作者：
H. Y. Kim;M. Mizutani;S. Miyazaki
研究了沉积Ti-Ni - (10.8 ~ 29.5)Zr非晶薄膜的结晶过程。低Zr含量的Ti - Ni - Zr沉积膜由于（Ti,Zr）Ni具有B2结构的结晶而呈现单一放热峰。相比之下，高Zr含量的Ti-Ni-Zr薄膜的结晶过程为两步。通过热循环试验，研究了873 ~ 1073k温度下Ti-Ni-Zr薄膜的形状记忆行为。随着Zr含量的增加，马氏体相变开始温度逐渐升高，达到最大值后，随着Zr含量的增加，马氏体相变开始温度逐渐降低。在高Zr含量薄膜中，相变温度与Zr含量呈负相关关系是由于在结晶热处理过程中形成了NiZr相。NiZr相的形成增加了滑移临界应力，但降低了恢复应变。
The crystallization process of as-deposited Ti–Ni–(10.8–29.5)Zr amorphous thin films was investigated. The Ti–Ni–Zr as-deposited films with a low Zr content exhibited a single exothermic peak due to the crystallization of (Ti,Zr)Ni with a B2 structure. In contrast, a two-step crystallization process was observed in the Ti–Ni–Zr thin films with a high Zr content. Shape memory behavior of Ti–Ni–Zr thin films heat treated at 873–1073K was investigated by thermal cycling tests under various stresses. The martensitic transformation start temperature increased with increasing Zr content until reaching the maximum value, then decreased with further increasing Zr content. The inverse dependence of transformation temperature on Zr content in the thin films with a high Zr content is due to the formation of a NiZr phase during the crystallization heat treatment. The formation of the NiZr phase increased the critical stress for slip but decreased the recovery strain.