METHOD FOR MANUFACTURING RARE EARTH MAGNET

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PROBLEM TO BE SOLVED : To provide a method for manufacturing a rare earth magnet which is less prone to the reduction in the magnetic characteristic even at high temperature. SOLUTION : Hydrogenated powders consisting of a hydrogenated alloy containing a hydrogen compound of a rare earth element, and an iron group element, are prepared. A heat shield layer is formed of a material whose thermal conductivity is lower than that κr of a rare earth-ferrous alloy so as to cover a surface of each hydrogenated alloy particles constituting hydrogenated powders to produce coated hydrogenated powders. Coated hydrogenated powders are compression molded to produce a hydrogenated powder compact. The dehydrogenation-treatment is applied to the hydrogenated powder compact to recombine the hydrogenated alloy and the rare earth-the iron group element to form a powder compact consisting of coated magnetic powders in which magnetic particles 20 consisting of the rare earth-the iron group alloy are coated with the heat shield layer 22. The powder compact is immersed in a molten metal to produce a magnet element (a rare earth magnet 1) in which a metal phase 3 is interposed between each coated magnet particles 2 constituting coated magnetic powders. The molten metal melts a metal whose thermal conductivity is higher than that κb of the component of the heat shield layer. COPYRIGHT : (C)2015, JPO&INPIT