Influence of Ta content on martensitic transformation and shape memory properties of Cu-Al-Ni-Mn shape memory alloy

Abstract

This study presents the effect of Ta addition on martensitic transformation behavior and shape memory properties of Cu82.6-xAl12.4Ni4Mn1Tax (x = 0, 1, 2 and 3 wt%) high-temperature shape memory alloys. The results indicated that martensite structure, phase components, transformation characteristics and shape recovery ratios of the Cu82.6-xAl12.4Ni4Mn1Tax alloys remarkably changed with the addition of Ta element. The alloys display dual-phase martensite structure (beta 1 '+gamma 1 ') for x = 0 and 1, whereas those for x = 2 and 3 have only the beta 1 ' martensite phase. It is seen that the shape memory properties of the alloys improve considerably as a result of the addition of Ta and the highest shape recovery ratio of 87.5% is achieved with 3 wt% Ta-added alloy.