Martensite Aging Effect and Thermal Cyclic Characteristics in Ti-Pd and Ti-Pd-Ni High Temperature Shape Memory Alloys

The effect of thermal cycling and aging in martensitic state in Ti-Pd-Ni alloys were investigated by DSC and TEM observations. It is shown that the thermal cycling causes the decreases in M, and Af temperatures in Ti50Pd50-xNix (x=10, 20, 30) alloys, but no obvious thermal cycling effect was observed in Ti50Pd50Pd40Ni10 alloys and the aging effect shows a curious feature, i.e., the Af temperature does not saturate even after relatively long time aging, which is considered to be due to the occurrence of recovery recrystallization during aging.