Research Progress on Ni-Mn-In Based Magnetic Refrigeration Alloys

New solid-state magnetic refrigeration technology based on magnetocaloric effects has attracted much attention due to its advantages of energy saving, high efficiency, and stability and reliability. This technology utilizes heat exchange between magnetic materials and external environments during magnetic phase transition to produce refrigeration effects. Ni-Mn-In based magnetic refrigeration alloys can produce an inverse magnetocaloric effect under a magnetic field and have a large magnetic entropy change. The crystal structure and phase transformation behavior of Ni-Mn-In based magnetic refrigeration alloys are described. Research progress on the influence of grain size, chemical composition and heat treatment process on the magnetocaloric effect of Ni-Mn-In based magnetic refrigeration alloys, as well as on improving mechanical properties of the alloys by microalloying is emphatically reviewed. The future research direction of this series of alloys is also prospected.