R-T-B-based rare earth magnet particles, and bonded magnets containing R-T-B-based rare earth magnet particles

    公开(公告)号:US11120932B2

    公开(公告)日:2021-09-14

    申请号:US14205894

    申请日:2014-03-12

    申请人: TODA KOGYO CORP.

    摘要: An object of the present invention is to enhance a coercive force of magnetic particles by promoting formation of a continuous R-rich grain boundary phase in a crystal grain boundary of a magnetic phase of the particles, and to thereby obtain R-T-B-based rare earth magnet particles further having a high residual magnetic flux density. The present invention relates to production of R-T-B-based rare earth magnet particles capable of exhibiting a high coercive force even when a content of Al therein is reduced, and a high residual magnetic flux density, in which formation of an R-rich grain boundary phase therein can be promoted by heat-treating Al-containing R-T-B-based rare earth magnet particles obtained by HDDR treatment in vacuum or in an Ar atmosphere at a temperature of not lower than 670° C. and not higher than 820° C. for a period of not less than 30 min and not more than 300 min.