Phase Transformation and Microstructures in Ni and Cu Base Ferromagnetic Shape Memory Alloys
Effect of chemical composition was investigated on martensitic transformation temperatures, Curie temperature, magnetization and microstructures for Ni-(Mn, Fe, Co)-Ga and Cu-Mn-Ga systems. In the Ni-(Mn, Fe, Co)-Ga alloys, which is a modification of Ni-Mn-Ga systems, the Af and TC over 400 K were achieved. Cu-Mn-Ga alloy exhibited shape memory effect at temperatures above 373 K and had TC over 400 K. Furthermore, Cu-Mn-Ga exhibits good ductility even in polycrystalline condition unlike the case of Ni-Mn-Ga. Effect of addition of the fourth element to improve the magnetic property is under investigation.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
T. Kushima et al., "Phase Transformation and Microstructures in Ni and Cu Base Ferromagnetic Shape Memory Alloys", Materials Science Forum, Vols. 539-543, pp. 3157-3162, 2007