Abstract: The effects of thermal cycles on the properties of CuZnAl shape memory alloys under different heating temperatures, pre-deformations ε and amounts of complex rare earth mixture added were researched with electronic microscopes. The results indicate that thermal cycles can increase the transformation temperature M_s of the alloys by 5-6℃. Increasing the pre-deforma-tion ε will decrease the necessary cycle times for stable two-way-shape memory property. However the shape recovery rate of the alloys will decrease when the pre-deformation exceeds 3.6%. The shape memory property of the alloys will change insignificantly if the amount of rare earth added is less than 0.10%. But the alloys without rare earth will have worse shape memory property after thermal cycles reach 1800 times.

Key words: shape memory property, pre-deformation, transformation temperature, thermal cycle, shape memory alloy