Exploring the Function Fatigue Behavior of Ferromagnetic Shape Memory Alloy

In the industrial applications of ferromagnetic shape memory alloy, the large magnetic field induced strain and long function fatigue life are the essential conditions for their application. In this cases, the ferromagnetic shape memory effect and the function fatigue of Ni₂MnGa under applied magnetic field has been investigated. The magnetic field induced strain appear typical nonlinearity increasing trend apparently with the applied magnetic field rising. Meanwhile, the magnetic field induced strain keep decreasing tendency as the applied magnetic field cycles increasing and the magnetic field induced strain kept a small value in a long cycle ranges of 400 to 10⁷. Furthermore, the sample appeared typical elastic deformation stage, twin martensite remigration stage and plastic deformation stage during compression test process. (paper)