The Ductility and Shape-Memory Properties of Ni–Mn–Ga–Cu Heusler Alloys

The effect of Cu addition on crystal structure, compressive properties and shape-memory effect of Ni50Mn25Ga25−xCux alloys was studied. With increasing Cu content, the type of crystal structure evolves following a sequence: L21 → 10M → 2M → 2M+γ. Addition of Cu significantly improves room temperature ductility. In polycrystalline Ni50Mn25Ga17Cu8 alloy, a full recoverable strain equal to 7 pct was achieved. High martensitic transformation temperature and large shape-memory effect makes this material potential candidate in high-temperature shape-memory applications.