Large elastocaloric effect in a polycrystalline Ni45.7Co4.2Mn37.3Sb12.8 alloy with low transformation strain

Ni-Co-Mn-Sb alloys can exhibit large elastocaloric effect characterized as stress-induced entropy change Delta S-sigma. However, the intrinsic large brittleness of polycrystalline alloys makes it difficult to directly measure the stress-induced temperature change Delta T-ad. Here, we demonstrate large elastocaloric effect in a directionally solidified Ni45.7Co4.2Mn37.3Sb12.8 alloy with enhanced mechanical properties. Large Delta T-ad up to 9.4 K was realized through compressive stress-induced martensitic transformation with a low transformation strain of 1.5%. Moreover, with integrating large Delta S-sigma up to 25.4 Jkg(-1) K-1 and wide working temperature window of 46 K, a giant refrigeration capacity RC sigma of 930 Jkg(-1) was achieved under the compressive stress of 250 MPa. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.