Giant elastocaloric effect in a Mn-rich Ni44Mn46Sn10 directionally solidified alloy

Abstract

The superelastic and elastocaloric properties of a Mn-rich Ni44Mn46Sn10 polycrystalline alloy prepared by directional solidification were studied. Owing to the coarse columnar shaped grains with strong <001>A preferred orientation, a large superelastic strain up to 8% and a transformation strain of 5.6% can be obtained through compressive stress induced martensitic transformation. Moreover, a giant adiabatic temperature variation up to -18 K was achieved on removing the stress. Such a remarkable elastocaloric effect is attributed to the large transformation entropy change through composition modification and the enhanced mechanical properties due to the formation of a highly textured microstructure in the directionally solidified alloy.