Large low-stress elastocaloric effect in Ti-Zr-Cr-Sn

The absence of high-performance elastocaloric refrigerant with low critical driving stress (sigma(cr)) hinders the practical application of elastocaloric solid-state refrigeration. Motivated by the remarkable superelasticity of the beta-type TiZrCrSn alloy, the elastocaloric effect of this alloy is studied in this work. An alloying strategy of decreasing Zr content is adopted to reduce the stability of austenite so as to lower sigma(cr). Ti67.5Zr26.5Cr2.7Sn3.3 possessing a small sigma(cr) (110 MPa), excellent superelasticity (4%) and mechanical properties is fabricated. An adiabatic temperature change of 8.3 K is detected at 360 K. Over a broad temperature window of 150 K (270-420 K), the excellent superelasticity and elastocaloric refrigeration performance can be sustained. The refrigeration capacity is estimated to be 1.6-2.8 J center dot g(-1), compared to those of NiTi and CuAlMn. This work is anticipated to provide a novel alloy platform for designing high-performance low-stress elastocaloric refrigerants.