PROCESS FOR PRODUCTION OF R-T-B BASED SINTERED MAGNETS AND R-T-B BASED SINTERED MAGNETS

摘要

A process for the production of R-T-B based sintered magnets which comprises: a step of preparing R-T-B based sintered magnet bodies (1); a step of preparing heavy rare earth element (RH) diffusion sources (2) that consist of a metallic RH (Dy and/or Tb) or an alloy thereof; a step of charging a treating chamber (3) with the sintered magnet bodies (1) and the RH diffusion sources (2) in such a manner that the sintered magnet bodies (1) and the RH diffusion sources (2) can move relatively, come close to each other, or come into contact with each other; and an RH diffusion step of heat-treating the sintered magnet bodies (1) and the RH diffusion sources (2) at 500 to 850°C for at least 10 minutes while moving the sintered magnet bodies (1) and the RH diffusion sources (2) continuously or intermittently in the treating chamber (3).