R-Fe-B SYSTEM RARE EARTH SINTERED MAGNET AND ITS METHOD FOR MANUFACTURING

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PROBLEM TO BE SOLVED : To form efficiently also in the interior of an R-Fe-B system rare earth sintered magnet body, main phase crystal grain particles in which a heavy rare earth element RH is condensed in its contour and to improve the retentivity while suppressing the lowering of residual magnetic flux. SOLUTION : The method for manufacturing an R-Fe-B system rare earth sintered magnet includes a process (A) which prepares at least one R-Fe-B system rare earth sintered magnet body having R2Fe14B type compound crystal grain particles containing light rare earth element RL (at least one kind of Nd and Pr) as a main rare earth element R as the main phase. After performing the process (A), a process (B) is performed which arranges a foil or powder containing heavy rare earth element RH (at least one kind selected from a group consisting of Dy, Ho, and Tb) in a treatment chamber together with the R-Fe-B system rare earth sintered magnet body, while being contacted to the R-Fe-B system rare earth sintered magnet body. Further, a process (C) is performed which, while supplying heavy rare earth element RH from the foil or the powder to the surface of the sintered magnet body by heating the sintered magnet body, makes it diffuse in the interior of the sintered magnet body. COPYRIGHT : (C)2008, JPO&INPIT