Abstract: This paper has reviewed NiTi based ternary NiTi X and binary NiAl high temperature shape memory alloys. The emphasis was laid on studying the relation between chemical composition,phase transformation temperatures and transformation hysteresis. It is indicated that the transformation temperatures increased evidently with increasing Pd content, especially when the alloy containing more than 33at% Pd. Every 1at% more Pd content addition led to an effect of about 20℃ increment of transformation temperature. An alloy with 40at% Pd can reach a transformation temperature of 379.8℃. The temperature hysteresis remained nearly constant and the latent heat enlarged linearly with Pd content increment.

Key words: TiNiPd, hig h temperatur e shape memo ry allo ys, phase transformation