Ni-Fe-Ga foam with hierarchical pore architecture was created by replication casting. The annealed foam had an open porosity 53% and reversible superelasticity with recoverable strain 4.9%. An adiabatic temperature change of 4.1 K with low hysteresis and coefficient of performance 22 were obtained under an external stress 70 MPa. The foam showed improved cyclic stability ($\sim 2.8\mathrm{K}$ in 194 cycles) because of low hysteresis loss under small stress and high crack initiation/propagation resistance in small size nodes and struts, which demonstrated a feasible strategy to enhance the mechanical and functional stabilities of ferromagnetic shape memory alloys via tailoring the material architectures. Nevertheless, the achieved elastocaloric cooling stability still cannot satisfy (${10}^7$ cycles) the commercial application, therefore, it should be further explored to become a promising candidate for elastocaloric material.

• Received 18 March 2020
• Revised 7 May 2020
• Accepted 27 May 2020

DOI:https://doi.org/10.1103/PhysRevMaterials.4.065403