Microstructure, martensitic transformation and excellent shape memory effect of Ga-alloyed Cu–Al–Mn–Fe shape-memory single crystal

Abstract

A Cu–10Al–6Mn–3Fe–4Ga (wt.%) single crystal was simply prepared, and its microstructure, reversible martensitic transformation, mechanical and SME properties were investigated. The results show that this single crystal consists of dominant 2H martensite retained L2 1 parent and fine Fe-rich nanoparticles. Its reversible martensitic transformation temperatures are respectively 313 K ( M s ), 299 K ( M f ), 339 K ( A s ), and 354 K ( A f ), which are suitable for practical applications. A large stress platform with a strain of approximately 8% was associated with the reorientation of existing martensite and stabilization of stress-induced martensite. Furthermore, full shape recovery characteristics are obtained all the time while changing the pre-strains from 6% to 11%. The maximum shape memory effect is up to 9.2% with a 100% shape recovery rate.