Orientation dependence of elastocaloric effect in an aged Ni-rich Ti-Ni alloy

Abstract

Elastocaloric effects caused by the stress-induced B2-R and the reverse martensitic transformations (B2: the parent phase, R: the martensite phase) were studied by using an aged single crystal of Ti-50.8Ni shape memory alloy including coherent precipitates of Ti3Ni4. Inverse elastocaloric effect was observed when tensile stress is applied in the [100]B2 direction, while conventional one was observed in the [111]B2 direction. This result implies that transformation strain in the [100]B2 direction is negative for any variants.