Thermal cycling behavior of an aged FeNiCoAlTa single-crystal shape memory alloy

In this study the thermal cycling behavior of differently aged [100]-oriented Fe-28Ni-17Co-11.5Al-2.5Ta (at.%) shape memory single crystals was investigated. The strain-temperature response determined from thermal cycling experiments revealed a strong dependency on the precipitate morphology, which was adjusted by aging heat treatments. Specifically, a high precipitate density in the microstructure leads to small phase transformation-induced strains and low stresses necessary for activation of the martensitic phase transformation. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.