Patent ID: 9368276
Filing Date: 2016-06-14
CPC Classification: B22F,C22C,H01F

Claim Text:
1. A method for producing a sintered R-T-B based magnet, the method comprising the steps of: providing a sintered R-T-B based magnet body; providing a solid RH diffusion source including a heavy rare-earth element RH (which is at least one of Dy and Tb) and 40 mass % to 60 mass % of Fe, the solid RH diffusion source having a solid physical shape; loading the sintered magnet body and the solid RH diffusion source into a processing chamber so that the magnet body and the solid RH diffusion source are movable relative to each other and are readily brought in contact with each other; and performing an RH diffusion process in which the sintered magnet body and the solid RH diffusion source are heated to a processing temperature of more than 850° C. through 1000° C. while being moved either continuously or discontinuously in the processing chamber, and changing a point of contact between the sintered magnet body and the solid RH diffusion source by rotating the processing chamber; wherein the RH diffusion process is carried out with a stirring aid member introduced into the processing chamber, the stirring aid member being made of zirconia, silicon nitride, silicon carbide, boron nitride or a ceramic that includes any combination of zirconia, silicon nitride, silicon carbide, and boron nitride; and the sintered magnet body, the solid RH diffusion source and the stirring aid member are stirred in the processing chamber during the RH diffusion process.