Orientation dependence of elastocaloric effect in a Cu71.3Al17.5Mn11.2 single crystal

Abstract

In this work, the orientation dependence of superelasticity and elastocaloric effect was systematically investigated in a Cu71.3Al17.5Mn11.2 single crystal, which was prepared by means of abnormal grain growth induced by cyclic heat treatment using a < 001 >A textured polycrystalline alloy as the precursor. By comparing the superelastic and elastocaloric response upon applying the compressive loading along the < 001 >A, < 110 >A and < 111 >A orientations, it was shown that the < 001 >A orientation can yield the largest transformation strain, the lowest transformation stress and the most remarkable elastocaloric response. Large stress-induced adiabatic temperature change (|ΔTad|) values of 12 K ∼ 15 K, covering a wide temperature window from 293 K to 453 K, were achieved upon removing a compressive loading of 500 MPa for the < 001 >A oriented single crystal. Moreover, favored by the relatively lower driving stress along the < 001 >A orientation, the specific adiabatic temperature variation (|ΔTad/σmax|) can be as large as 107.3 K/GPa. This work clearly demonstrates the strong influence of crystallographic orientation on the elastocaloric properties resulting from stress-induced martensitic transformation, which is expected to provide some instructions for designing high-performance elastocaloric materials.