Enhanced elastocaloric effect and specific adiabatic temperature variation in Ni-Mn-In-Si-Cu shape memory alloys

Abstract

In this work, we demonstrate a giant elastocaloric effect in a Ni50Mn33In14Si1Cu2 alloy. Owing to the large transformation entropy change and low thermal hysteresis, giant adiabatic temperature change (ΔTad) of − 18.2 K is obtained on unloading from a maximum compressive strain of 6 % with a low stress of 145 MPa. Moreover, large specific adiabatic temperature variation (ΔTad/σmax) up to 126 K/GPa has been achieved. This ΔTad/σmax value significantly exceeds those in the typical shape memory alloys. The present results demonstrate that the target alloy exhibits a distinct advantage in the strength of elastocaloric effect, being crucial for practical applications of solid-state refrigeration. In addition, it is found that the cyclic stability can be effectively enhanced by one-step overstress superelastic training for the first cycle.