Elastocaloric effect in bamboo-grained Cu71.1Al17.2Mn11.7 microwires.

Bamboo-grained Cu 71.1 Al 17.2 Mn 11.7 microwires with diameter ∼150 μm were created by Taylor-Ulitovsky method and subsequent annealing. The grain architecture dependent superelasticity (SE) and elastocaloric effects (eCE) were confirmed. The bamboo-grained microwires exhibited low stress hysteresis loss during SE due to the reduced constraints caused by grain boundary, which is favorable for the mobility of martensite-austenite interface. Consequently, a large isothermal entropy change ∼ 21 J/kg K with a wide temperature range 90 K was achieved. The produced adiabatic temperature change (ΔT ad) reached −11.9 K under a maximum stress 400 MPa. A stable ΔT ad of −5.6 K showing little degradation in 200 eCE cycles was found with applied stress 325 MPa. This work reveals a fact that the bamboo-grained Cu–Al–Mn microwire may act as a desirable material for miniature solid-state refrigeration devices. Image 1 • Bamboo-grained Cu 71.1 Al 17.2 Mn 11.7 microwires were successfully prepared with reduced stress hysteresis (∼40 MPa). • A large isothermal entropy change ∼ 21 J/kg K with a wide temperature range of 90 K was achieved. • A large reversible adiabatic temperature change ΔT ad of −11.9 K was obtained at room temperature. • A stable ΔT ad of −5.6 K showing no degradation in 200 elastocaloric cycles was achieved at room temperature. [ABSTRACT FROM AUTHOR]