US 11,810,710 B2
Sintered R-T-B based magnet and method for producing the same
Noriyuki Nozawa, Tokyo (JP)
Assigned to PROTERIAL, LTD., Tokyo (JP)
Filed by PROTERIAL, LTD., Tokyo (JP)
Filed on Feb. 25, 2022, as Appl. No. 17/680,597.
Claims priority of application No. 2021-049196 (JP), filed on Mar. 23, 2021; and application No. 2021-114084 (JP), filed on Jul. 9, 2021.
Prior Publication US 2022/0310319 A1, Sep. 29, 2022
Int. Cl. H01F 1/057 (2006.01); B22F 3/24 (2006.01); H01F 41/02 (2006.01); C22C 28/00 (2006.01); B22F 3/26 (2006.01); C22F 1/16 (2006.01); C22C 1/04 (2023.01)
CPC H01F 41/0293 (2013.01) [B22F 3/26 (2013.01); C22C 1/04 (2013.01); C22C 28/00 (2013.01); C22F 1/16 (2013.01); H01F 1/0577 (2013.01); B22F 2003/248 (2013.01); B22F 2301/45 (2013.01); C22C 2202/02 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A sintered R-T-B based magnet, comprising:
R (R is a rare-earth element and contains, with no exception, at least one selected from the group consisting of Nd, Pr and Ce);
T (T is at least one selected from the group consisting of Fe, Co, Al, Mn and Si, and contains Fe with no exception);
B; and
at least one selected from the group consisting of Cu, Ga, Ni, Ag, Zn and Sn,
wherein a molar ratio [T]/[B] of T with respect to B in a surface region of the sintered R-T-B based magnet is lower than a molar ratio [T]/[B] of T with respect to B in a central region of the sintered R-T-B based magnet.