| 摘要 |
[Problem] To provide a method for producing a sintered R-T-B based magnet which can get a heavy rare-earth element RH diffused efficiently inside a sintered R-T-B based magnet body. [Solution] This method for producing a sintered R-T-B based magnet includes the steps of: providing a sintered R-T-B based magnet body (where R is a rare-earth element and T is a transition metal element which is mostly comprised of Fe); providing an RH diffusion source which is an alloy comprising: 0.2 mass % to 18 mass % of light rare-earth element RL (which is at least one of Nd and Pr); 40 mass % to 70 mass % of Fe; and a heavy rare-earth element RH (which is at least one of Dy and Tb) as the balance, wherein the heavy rare-earth element RH and Fe have a mass ratio RH:Fe which falls within the range of three to two to three to seven; and performing an RH diffusion process by loading the sintered R-T-B based magnet body and the RH diffusion source into a processing chamber so that the sintered R-T-B based magnet body and the RH diffusion source are movable relative to each other and brought close to, or in contact with, each other, and by heating the sintered R-T-B based magnet body and the RH diffusion source to a processing temperature of 700° C. to 1000° C. while moving the sintered R-T-B based magnet body and the RH diffusion source in the processing chamber either continuously or discontinuously. |
