Superelastic Deformation Behaviors Based on Phase Transformation Bands in TiNi Shape Memory Alloy
Superelastic Deformation Behaviors Based on Phase Transformation Bands in TiNi Shape Memory Alloy
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DOI：
10.2320/matertrans.47.670
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发表时间：
2006-03
影响因子：
1.2
通讯作者：
E. Pieczyska;H. Tobushi;S. Gadaj;W. Nowacki
中科院分区：
文献类型：
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作者：
E. Pieczyska;H. Tobushi;S. Gadaj;W. Nowacki
介绍了TiNi形状记忆合金（SMA）中类吕德斯相变带的性质和超弹性变形行为的特点。温度分布伴随着应力引起的相变中的SMA被发现使用红外技术和用于调查成核和进一步发展的带的马氏体和逆变换。基于温度和相关的机械特性，它是注意到，刚刚越过一定的阈值应力后，窄带相当高的温度，约8 K，对应于马氏体相，出现从中央部分的试样和发展的两个试样的边界。一些这样的带平行于彼此发生在较高的应力和移动到试样夹具，以及他们的下一代，在几乎垂直的方向发展。在卸载过程中也观察到了温度分布的不均匀场，同时发生了逆相变，也是不均匀的，并且与显着的温度降低有关。通过不同应变率下的试验，研究了应变率对材料力学性能的影响。讨论了马氏体相变和逆相变的热力学性质。
Properties and characteristics of superelastic deformation behavior based on Luders-Like phase transformation bands in TiNi shape memory alloy (SMA) are presented. Temperature distributions accompanying the stress-induced phase transformations in the SMA are found using the infrared technique and employed for the investigation into nucleation and further development of the bands of martensitic and reverse transformations. Based on the temperature and the relevant mechanical characteristics it is noticed that just after crossing a certain threshold stress, narrow bands of considerably higher temperature, about 8 K, corresponding to the martensitic phase, appear starting from the central part of the specimen and developing towards the both specimen borders. A few such bands parallel to each other occur at higher stresses and move towards the specimen grips, as well as their next generation, developing in almost perpendicular direction. The heterogeneous field of the temperature distribution was observed also during the unloading process, while the reverse transformation occurred, also inhomogeneous and related to the significant temperature decrease. Based on the tests carried out with various strain rates, an influence of the strain rate on the mechanical behavior was presented. Thermomechanical aspects of the martensitic and the reverse transformations were discussed.