La0.8Ce0.2(Fe0.95Co0.05)11.8Si1.2/Sn42Bi58 magnetocaloric composites prepared by low temperature hot pressing

Highlights: • La_0.8Ce_0.2(Fe_0.95,Co_0.05)_11.8Si_1.2/Sn₄₂Bi₅₈ composites were prepared by low temperature HP. • The molten Sn-Bi alloy has a buffering and filling effect for the parent alloy. • The thermal conductivity and mechanical property of the composites were improved remarkably. • Low temperature HP technique can be used in mass production of high performance MCMs. La_0.8Ce_0.2(Fe_0.95Co_0.05)_11.8Si_1.2/Sn₄₂Bi₅₈ magnetic refrigeration bulk composites were prepared by low temperature hot pressing (HP) technique at 138 °C. Sn-Bi eutectic alloy (Sn₄₂Bi₅₈) was used as binder. During the process of HP, the molten Sn₄₂Bi₅₈ alloy filled the gaps between the particles. Hence, the composites retained good magnetocaloric properties. The density of the composites gradually increased at larger HP pressure. The thermal conductivity and mechanical property of the composites also improved remarkably. By controlling the processing conditions, a series of La_0.8Ce_0.2(Fe_0.95Co_0.05)_11.8Si_1.2/Sn₄₂Bi₅₈ bulk composites with high entropy change values of 5.57–6.70 J/(kg·K) at 2 T, high thermal conductivity of 10.72–19.64 W/(m·K) and compressive strength of 189–303 MPa were obtained. The present results indicate that low temperature HP technique can be used in mass production of high performance magnetocaloric materials.