Effects of Gd addition on the microstructure, mechanical properties and shape memory effect of polycrystalline Cu-Al-Ni shape memory alloy

The effects of Gd addition on the microstructure, mechanical properties and shape memory effect of (Cu-13.0Al-4.0Ni)-xGd (x=0, 0.3, 0.9, 1.5 and 6) (wt%) alloys were investigated. The results showed that the grain of (Cu-13.0Al-4.0Ni)-xGd alloys was refined by the Gd addition. The 18R martensite and a small amount of 2 h martensite were present for x<0.9 wt%, and dual phases containing 18R martensite and hexagonal structured AlCu4Gd phase were observed for x≥0.9 wt%. In addition, Gd addition significantly enhanced the mechanical and shape memory properties. The compressive fracture strain of 15.3% and reversible strain of 6.6% were obtained in (Cu-13.0Al-4.0Ni)-0.3Gd alloy.