Unveiling the interplay and sensitivity of the elastocaloric response of CuZnAl alloys to strain rate and temperature

This study presents a comprehensive evaluation of the elastocaloric effect in a Cu 68 . 6 Zn 14 . 8 Al 16 . 6 shape-memory alloy single crystal, analyzing its thermodynamic response across a broad spectrum of strain rates ( 3 . 4 × 1 0 − 4 to 0 . 35 s − 1 ) and testing temperatures. Direct measurements demonstrate that the adiabatic temperature change saturates at a strain rate of 0 . 15 s − 1 , reaching a maximum of 9 . 2 K . Crucially, owing to the ultra-low baseline hysteresis of the single crystal, this thermal response is highly symmetrical during both the exothermic loading and endothermic cooling phases, corresponding to a transformation entropy change of 24 . 9 J kg − 1 K − 1 . Uniquely, this work systematically addresses the dynamic evolution of mechanical dissipation; we demonstrate that although the unrecoverable work initially increases by up to 300% before saturating under near-adiabatic conditions, the concurrent enhancement in cooling capacity heavily outweighs this penalty, resulting in a net increase in the material coefficient of performance. Coupled with an outstanding elastocaloric responsivity of ∼ 77 K GPa − 1 , these findings highlight the exceptional efficiency of Cu-Zn-Al single crystals and establish dynamic strain rate optimization as a key engineering strategy for high-frequency solid-state cooling devices. • First dynamic elastocaloric analysis of Cu-Zn-Al single crystals. • Symmetrical near-adiabatic temperature change of 9.2 K saturates at 0.15 s − 1 . • Cooling capacity enhancement outweighs dynamic hysteresis, increasing the COP. • Outstanding elastocaloric responsivity of ∼ 77 K GPa − 1 enables compact devices.