Temperature dependence of indentation recovery ratios in austenitic and martensitic shape memory alloys

摘要

Instrumented microindentation (IM) on two Ni-Ti shape memory alloys (SMAs), where one is austenitic and the other is martensitic at room temperature, were conducted from 40 to 150°C. Results show that the depth and work recovery ratios, η_d and η_w respectively, are complementary to each other. While η_d decreases gradually with temperature for austenite, it drops markedly for the martensite in the martensite-to-austenite transformation regime. These results affirm the utility of IM for characterizing SMAs.