Effect of Strain Rate and Measuring Temperature on Elastocaloric Effect and Multi-caloric Properties of Co37.5 Ni34.5 Al28 Paramagnetic Shape Memory Alloy

Abstract

In this study, the elastocaloric and magnetocaloric effects in a paramagnetic shape memory alloy, i.e., Co37.5 Ni34.5 Al28 alloy were investigated. The study reveals that the alloy shows an elastocaloric effect with a temperature change of 2.2 K under 400 Mpa keeping a strain rate of 0.25 s−1. It shows a temperature change of over 1 K within a temperature span of 50 K including the room temperature. Under the same stress, with a strain rate of 0.50 s−1, the material shows a temperature change of 2.7 K and gives more than 1 K temperature change within a span of 75 K including the ambient temperature. However, increasing the strain rate to 0.62 s−1 causes the material to break down. This shows that under a certain limit, the increase in the strain rate increases the elastocaloric temperature change and enhances the temperature window of the material along with the peak shifts toward lower measuring temperatures. Moreover, the study deduces that the material also exhibits a magnetocaloric effect. The study also reveals that both of the effects show temperature changes with the same sign and in the same region of the working temperature, thus enhancing one another.