Martensitic transformation and mechanical properties in an aged Ni–Mn–Ga–Ti ferromagnetic shape memory alloy

Abstract The martensitic transformation behavior and mechanical properties were investigated in a Ti-doped Ni 53 Mn 23.5 Ga 18.5 Ti 5 alloy aged at 873 K for different durations. It is shown that the volume fraction of the Ni 3 Ti phase increases and the Ni content in the matrix reduces with increasing aging time, resulting in the decrease of the martensitic transformation temperatures. The precipitation of Ni 3 Ti particles strengthens the matrix, resulting in the increasing in the fracture toughness. Fracture morphology observation shows the fracture type changing from intergranular brittleness fracture to a mixture of intergranular and transgranular ductile failure is responsible for the improved mechanical properties.