METHOD FOR MANUFACTURING R-T-B-BASED SINTERED MAGNET

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PROBLEM TO BE SOLVED : To provide a method for manufacturing an R-T-B-based sintered magnet having a high intrinsic coercive force HcJ and arranged so that the reduction in residual magnetic flux density Br at a high temperature is suppressed. SOLUTION : A method for manufacturing an R-T-B-based sintered magnet comprises : 1) a step where a sintered compact having a main phase of an intermetallic compound including rare earth elements including neodymium (Nd), iron (Fe) and boron (B) and expressed by the general formula below is formed; 2) a step where a heavy-rare-earth-element-supply source including at least one of dysprosium (Dy) and terbium (Tb), and the sintered compact are set in a container, and then heated at a first diffusion temperature, thereby diffusing the at least one of dysprosium (Dy) and terbium (Tb) from the heavy-rare-earth-element-supply source into the sintered compact; and 3) a step where after the step 2), an aluminum supply source including aluminum (Al) and the sintered compact with the at least one of dysprosium (Dy) and terbium (Tb) diffused from the heavy-rare-earth-element-supply source thereinto are set in a container, and then heated at a second diffusion temperature lower than the first diffusion temperature, and ranging from 600 to 760°C, thereby diffusing aluminum (Al) from the aluminum supply source into the sintered compact. General Formula : R2T14B (where R represents at least one rare earth element including 50 mass% or more of neodymium (Nd), and T represents iron (Fe) or a combination of iron (Fe) and cobalt (Co).) COPYRIGHT : (C)2014, JPO&INPIT