V-shape in Young's modulus versus strain relationship in shape memory alloys upon mechanical loading
- 作者：Huang ; W.M. ; Wu ; J.A. ; Lim ; B.Y. ; Vahhi ; I.E.
- 关键词：Young's modulus ; Shape memory alloy ; Phase transformation ; Reorientation ; Surface relief
- 刊名：Journal of Alloys and Compounds
- 出版年：2005
- 期刊代码：45_09258388
- 类别：ms
- 出版时间：March 22, 2005
- 卷：390
- 期：1-2
- 页码：175-181
- 文件大小：476 K
摘要
The evolution of Young's modulus in NiTi polycrystalline wires of different initial phases in uniaxial tension was investigated. A V-shape with the bottom at round the hardening start point was found in all experiments. This is a phenomenon that has not yet been reported in the literature. Similar phenomenon was also observed in an austenite CuAlNi single crystal under uniaxial compression although appearing within a much narrower strain range. Optical observation and Wyko interferometer study of the CuAlNi sample surface revealed that the occurrence of V-shape is accompanied by the abrupt reorientation of martensite variant(s). It is concluded that same mechanism should be responsible for the similar phenomenon in polycrystals.