A highly plastic Ni50Mn25Cu18Ga7 high-temperature shape memory alloy

Since the discovery of NiMnGa shape memory alloys, including the ferromagnetic shape memory alloys and high-temperature shape memory alloys, the severe brittleness, especially the grain-boundary brittleness, has been a crucial bottleneck hindering their development. Here, high plasticity is reported in a high-temperature shape memory alloy, Ni50Mn25Cu18Ga7, with the martensitic transformation at 615 °C and face-centered tetragonal martensite. The tensile stress and strain are 488.7 MPa and 11.7%, respectively. A compressive true strain of 70% is monitored without fracture.