Orientation dependence of stress-induced phase transformation and dislocation plasticity in NiTi shape memory alloys on the micro scale
Orientation dependence of stress-induced phase transformation and dislocation plasticity in NiTi shape memory alloys on the micro scale
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DOI：
10.1016/j.msea.2012.01.042
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发表时间：
2012-03-15
期刊：
影响因子：
6.4
通讯作者：
Eggeler, G.
中科院分区：
文献类型：
--
作者：
Pfetzing-Micklich, J.;Ghisleni, R.;Eggeler, G.
NiTi形状记忆合金可用作微驱动器和小型伪弹性元件。因此，有必要在微观尺度上表征它们的力学性能。在之前的几项研究中，对不同的NiTi合金进行了这样的测试(纳米压痕、柱子压缩)。然而，关于塑性变形和马氏体相变之间的耦合问题，并没有得到一致的结果。此外，目前还不清楚材料对微观尺度上的载荷的反应是否反映了其大尺度的机械各向异性。在这项研究中，我们研究了一种二元、固溶处理的无析出NiTi合金，并在方向、方向和方向上压缩小柱子。结合扫描电子显微镜和解剖后的透射电子显微镜对力学结果进行了分析。我们确定了变形机制，并表明存在变形各向异性。结果表明，微柱试验的结果与以往宏观调查的定性结果吻合较好。(C)2012爱思唯尔B.V.保留所有权利。
NiTi shape memory alloys can be used as micro actuators and small scale pseudoelastic components. Therefore there is a need to characterize their mechanical properties on the micro scale. In several previous studies, such tests (nanoindentation, pillar compression) were performed for different NiTi alloys. However, no consistent results concerning the coupling between plastic deformation and martensitic transformation were obtained. Moreover it is unclear whether the material's response to loading on the micro scale reflects its large scale mechanical anisotropy. In this study, we investigate a binary, solution annealed precipitate free NiTi alloy and compress small pillars in -, - and -directions. Mechanical results are analyzed in the light of SEM and post-mortem TEM investigations. We identify deformation mechanisms and show that there is deformation anisotropy. We show that micro pillar testing yields results which are in good qualitative agreement with previous work from macroscopic investigations. (C) 2012 Elsevier B.V. All rights reserved.