Influence of thermal treatments on the long range order and the two way shape memory effect induced by stabilization in Cu–Al–Be single crystals

The influence of thermal treatments on the behavior of Cu–Al–Be single crystals, which transform martensitically, were analyzed. Aging in the martensite in the presence of a sufficiently high excess of vacancy concentration leads to stabilization and an increase of 40°C in the martensitic transformation temperature Ms, similar to Cu–Zn–Al. The stabilizing treatment is sufficient to obtain a full two way shape memory effect (TWME). Stabilization and TWME are absent when the excess vacancies have annealed out. The results are compared with those for Cu–Zn–Al and Cu–Al–Ni single crystals.