Effect of aging on transformation temperatures and microstructure of an Fe-doped Ni–Mn–Ga ferromagnetic shape memory alloy

Effect of aging on transformation temperatures and microstructure of an Fe-doped Ni–Mn–Ga alloy has been studied by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). DSC results show the transformation temperatures can be obviously raised by aging. When the aging temperature increases, the transformation temperatures gradually decrease to the minimum values and then increase slightly upon further increasing the aging temperature. The defects introduced by aging should be responsible for the change of transformation temperatures. In the sample aged at 573 K for 30 min, a large number of stacking faults are observed by TEM.