Comparison of two way shape memory effect for a poly, BI and single crystal of A Cu-Zn-Al-Co alloy

Abstract

The Two Way Shape Memory Effect (TWSME) is associated with the growth of particular martensite variants. This preferential growth can be obtained by several training routes, all of them based on thermomechanical cycling. A new concept of training has been developed for Cu-based alloys in recent years. The training method involves the stabilization of the stress induced martensite (SSIM) by a thermal treatment which depends on the ally composition. The obtained SSIM allows control of the nucleation and growth of particular martensite variants during subsequent thermal cycles, thus providing TWSME. The aim of the present work is to study the optimum TWSME that can be obtained in a Cu-Zn-Al-Co allow in relation to the influence of grain boundaries. This has been achieved by training poly-, bi- and single crystals of the same alloy.