Stress-Induced Thermoelastic Martensitic Transformations and Functional Properties in [011]-oriented NiTiHfPd Single Crystals

Abstract

The stress-induced martensitic transformation in the [011]-oriented Ni45.3Ti29.7Hf20Pd5 (at. %) single crystals in as-grown, homogenized and aged states were investigated in compression. It is experimentally shown that heat treatments of single crystals result in increase in martensitic transformation temperatures, two-fold decrease in reversible strain and increase in strain-hardening coefficient. As-grown single crystals demonstrate large temperature range of superelasticity (up to 140 K), large reversible strain (up to 4.3%) and large work output in comparison with homogenized and aged crystals.