Effects of training temperature on the two way memory effect in a CuZnAl alloy

Abstract

The applications of Cu-Zn-Al shape memory alloys are associated with the two way memory effect (TWME) in many cases, and thus have been thoroughly studied by many researchers. It was generally believed that the formation of preferential thermoelastic martensite is the origin for the TWME in Cu-Zn-Al alloys. In order to obtain stable forming paths for preferential martensite, samples should be subjected to a thermomechanical training. Presently, the TWME can be achieved by cycles of shape memory effect training or stress induced martensite (SIM) training, as well as a series of combined SIM and SME training. The procedures of combined SIM and SME training are the most effective to the induction of TWME in Cu-Zn-Al shape memory alloys. In the present investigation, the authors focused on the effects of the upper limit training temperature Tp on the reproducibility of the TWME, and as a result, the optimum Tp temperature for the TWME training was found in a Cu26Zn4Al shape memory alloy.