| 主权项 |
1: A method for producing a sintered R-T-B based magnet, the method comprising the steps of:
stacking RH diffusion sources (each being a metal or alloy, of which at least 80 at % is a heavy rare-earth element RH that is at least one of Dy and Tb) and sintered R-T-B based magnet bodies (where R is at least one of the rare-earth elements and T is at least one of the transition metal elements and always includes Fe) alternately one upon the other with a flat plate holding member having openings interposed between each pair of the diffusion source and the magnet body, thereby forming a multilayer structure; loading the multilayer structure in a process vessel; (A) performing an RH supply-diffusion process at a pressure of 2.0 Pa to 50 Pa and at a temperature of 800° C. to 950° C. in the process vessel; and (B) performing an RH diffusion process at a pressure of 150 Pa to 2 kPa and at a temperature of 800° C. to 950° C. in the process vessel, and wherein the method includes the step of carrying out the steps (A) and (B) alternately and repeatedly at least twice. |
