Stress-Induced Transformation and Temperature-Induced Transformation in Cu-Zn-Al Single Crystals

Abstract
The stress-induced martensitic transformation has been studied at different temperatures T>Ms. The application of a stress σ on a shape memory alloy leads to the apparition of oriented variants of martensite in the direction of the stress. It causes the superelastic effect. Beyond a critical stress σ_c, variants grow until parent phase diseappears. But martensitic transformation can be also induced by temperature. During a superelastic test, the sample has been overheat, then cooled at a constant deformation. It could be noticed that stress moves with temperature and that a low hysteresis appeared.