Cryogenic (Cu64.5Al24Mn11.5)99.5Cr0.5 superelastic alloy with broad temperature window of elastocaloric effect

Abstract

We report giant elastocaloric effect over a broad temperature window from 90 to 420 K in a Cr-doped directionally solidified (Cu64.5Al24Mn11.5)99.5Cr0.5 cryogenic shape memory alloy with ⟨001⟩A preferred orientation. Even at the temperature down to 90 K, the ΔTad values upon loading and unloading can be as large as 6.9 and −5.6 K, respectively. The combination of giant elastocaloric effect and broad temperature range thus yields a pronounced refrigeration capacity of 4.71 J g−1, well beyond those in the cryogenic elastocaloric materials demonstrated before. Moreover, large ΔTad values higher than 7.3 K remain stable for more than 1200 superelastic cycles at liquefied natural gas temperature (∼110 K) with a low degradation rate (5.8 × 10−4 K/cycle), showing great potential for cryogenic elastocaloric cooling applications.