Inverse elastocaloric effect in a Ti-Ni alloy containing aligned coherent particles of Ti3Ni4

We have detected an inverse elastocaloric effect in a Ti-51Ni (at%) alloy which contains aligned coherent particles of Ti3Ni4 formed by aging under tensile stress. In this alloy, the temperature of the specimen decreases when stress is applied due to a stress-induced reverse martensitic transformation (from the R-phase to the B2-phase) The temperature decrease caused by this effect is about 1.1 K at 300 K. The internal stress field around the Ti3Ni4 precipitate is responsible for this effect. A further increase in the tensile stress causes a temperature rise due to a conventional elastocaloric effect. (C) 2016 Elsevier Ltd. All rights reserved.