Effect of La addition on the microstructure and martensitic transformation of Ni-Ti-La alloys

The effect of the addition of the rare earth element La on the microstructure and martensitic transformation behavior of Ni50Ti50-xLax (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9) alloys was investigated experimentally. The microstructure of Ni-Ti-La alloys consists of the near-equiatomic TiNi matrix and LaNi precipitates. One-step martensitic transformation was observed in all Ni-Ti-La alloys. The martensitic transformation start temperatures decrease gradually with the increase of La fraction in Ni-Ti-La alloys.