Flexocaloric effect in a Cu-Al-Ni single crystal

We present a study of flexocaloric effect in superelastic materials exhibiting structural transitions. Three point bending experiments are performed on a Cu-Al-Ni single crystal undergoing a martensitic transition. During slow isothermal processes we measure bent beam profiles by optical imaging and the vertical force versus vertical deflection. Under fast bending and unbending protocols we measure the adiabatic evolution of temperature profiles by infrared imaging. From the temperature data we determine the evolution of heat source and heat sink profiles. Finally, we also study the location of acoustic emission events during the bending/unbending experiment. Our observations are consistent with predictions from a Ginzburg-Landau model combined with a vibrational model for a beam near a ferroelastic transition. The study allows to identify the main physical parameters relevant for flexocaloric applications.

Reference: Flexocaloric effect in superelastic materials, Clàudia Pérez-Junyent, Marcel Porta, Emma Valdés, Lluís Mañosa, Antoni Planes, Avadh Saxena & Eduard Vives, APL Mater. 10, 121103 (2022)