Shape Memory and Elastocaloric Effect in Au 7 Cu 5 Al 4 Shape Memory Alloy

The shape memory and elastocaloric properties of Au7Cu5Al4 polycrystalline shape memory alloy were investigated. The alloy exhibits a reversible martensitic transformation from body-centered cubic (BCC) austenite to body-center tetragonal (BCT) martensite. During the load-biased thermal cycling test, the recoverable transformation strain increased with increasing stress and saturated at about 1.4% under 75 MPa. The entropy change and the relative cooling power under 95 MPa were determined to be 7.2 J·K-1·kg-1 and 74.4 J·kg-1, respectively. Our results suggest that the Au-Cu-Al shape memory alloy can serve as a candidate for actuator and elastocaloric application in harsh environments.