Room temperature elastocaloric effect in polycrystalline Ni51Mn34In8Sn7 alloy

•Increase of strain rate improves the reversibility of structural transition.•ΔT increases with increasing strain rate and stress almost linearly.•Large room temperature ΔT (4.2 K) is obtained by optimizing strain rate and stress. Room temperature elastocaloric effect as well as the effects of strain rate and loading stress have been studied in polycrystalline Ni51Mn34In8Sn7. The increase of strain rate reduces plastic deformation and lattice invariant strain, thus improving the superelasticity. Higher strain rate and stress facilitate the stress-induced structural transition and adiabatic environment, and so the temperature change (ΔT) increases at a rate of 1.77 K (1% s−1)−1 and 1.78 K (102 MPa)−1. A large ΔT of 4.2 K is obtained by optimizing the strain rate and loading stress, which is comparable to or even larger than those of many NiMn-based alloys at room temperature. This result suggests polycrystalline Ni51Mn34In8Sn7 as a desirable material for room temperature elastocaloric refrigeration.