Pseudoelastic cycling in Cu-Al-Be single crystals: Interaction with diffusive phenomena

Abstract
CuAlBe alloys exhibit martensitic transformations and several properties related to this transformation such as the shape memory effect, pseudoelasticity and the two way shape memory effect. In this work results concerning pseudoelastic cycling of CuAlBe single crystals are presented and discussed. Particularly noticeable is the strong effect of diffusive phenomena on the stress strain curves obtained at test temperatures between 333 K and 373 K. In effect, a stronger stabilization of the martensite is observed during cycling as compared with the stabilization effect upon static conditions, which was found to be negligible at the same test temperatures. Results also indicate that the recovery of the austenitic phase plays a significant role during cycling. The generation of vacancies and the increase in their mobility have been considered in order to explain the observed behavior.