METHOD FOR PRODUCING R-T-B SINTERED MAGNET

PROBLEM TO BE SOLVED : To provide a method for producing an R-T-B sintered magnet having high Br and high HcJ while reducing the content of heavy rare earth elements. SOLUTION : This invention relates to an R-T-B-M sintered magnet with the mol ratio of [T]/[B] of more than 14.0, which is obtained by the steps of : preparing an R-T-B-M sintered body with the mol ratio of [T]/[B] of 14.0 or less; preparing an R-Cu-Ga-Fe-A alloy; bringing at least part of the surface of the R-T-B-M sintered body into contact with at least part of the R-Cu-Ga-Fe-A alloy, and performing first heat treatment at 700°C or more and 1100°C or less; and performing second heat treatment to the R-T-B-M sintered body subjected to the first heat treatment, at 450°C or more and 600°C or less. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2018, JPO&INPIT