A Dual-phase Ni-Mn-Ga-Gd High-temperature Shape Memory Alloy with Large Shape Recovery Ratio

The shape memory effect and recovery ratio of dual-phase Ni58Mn25G16.9Gd0.1 alloy were investigated by bend test. The results show that this alloy exhibits good shape recovery capability. The recovery ratio of 86% is obtained with bend pre-strain of 4.6% after heating, which is larger than that of other reported dual-phase Ni-Mn-Ga alloys. This characteristic is attributed to the critical slip stress increasing of γ phase by small amount of Gd addition, improving the ability of γ phase to resist irreversible deformation.