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.

Solid-state refrigeration based on elastocaloric materials (eCMs) requires reversibility and repeatability. However, the intrinsic intergranular brittleness of ferromagnetic shape memory alloys (FMSMAs) limits fatigue life and, thus, is the crucial bottleneck for its industrial applications. Significant cyclic stability of elastocaloric effects (eCE) via 53% porosity in Ni-Fe-Ga FMSMA has already been proven. Here, Ni-Fe-Ga foams (single-/hierarchical pores) with high porosity of 64% and 73% via tailoring the material’s architecture to optimize the eCE performances are studied. A completely reversible superelastic behavior at room temperature (297 K) is demonstrated in high porosity (64–73%) Ni-Fe-Ga foams with small stress hysteresis, which is greatly conducive to durable fatigue life. Consequentially, hierarchical pore foam with 64% porosity exhibits a maximum reversible ∆T_ad of 2.0 K at much lower stress of 45 MPa with a large COP_mat of 34. Moreover, it shows stable elastocaloric behavior (ΔT_ad = 2.0 K) over >300 superelastic cycles with no significant deterioration. The enhanced eCE cyclability can be attributed to the pore hierarchies, which remarkably reduce the grain boundary constraints and/or limit the propagation of cracks to induce multiple stress-induced martensitic transformations (MTs). Therefore, this work paves the way for designing durable fatigue life FMSMAs as promising eCMs by manipulating the material architectures.