Patent ID: 8287661

Claim:
A method for producing a sintered R-T-B based magnet, the method comprising the steps of: providing R-T-B based alloy powders A and B, wherein the powder A includes 27.3 mass % to 31.2 mass % of R (which is at least one of the rare-earth elements), 0.92 mass % to 1.15 mass % of B, and T as the balance (where T is either Fe alone or Fe and Co and where Co accounts for at most 20 mass % of T if T includes Fe and Co) and wherein the powder B includes 27.3 mass % to 36.0 mass % of R (which is at least one of the rare-earth elements), 0.92 mass % to 1.15 mass % of B, and T as the balance (where T is either Fe alone or Fe and Co and where Co accounts for at most 20 mass % of T if T includes Fe and Co); mixing these two R-T-B based alloy powders A and B together; compacting the mixed R-T-B based alloy powder to obtain a compact with a predetermined shape; and sintering the compact, wherein R included in the R-T-B based alloy powder B includes 4 mass % to 36 mass % of heavy rare-earth element RH, which is at least one of Dy and Tb, and wherein the content of the heavy rare-earth element RH in the R-T-B based alloy powder B is larger by at least 4 mass % than the content of the heavy rare-earth element RH in the R-T-B based alloy powder A, and wherein the particle size D50 of the R-T-B based alloy powder B is smaller by at least 1.0 Î¼m than the particle size D50 of the R-T-B based alloy powder A.