US 12,488,918 B2
Neodymium-iron-boron magnet material, raw material composition preparation method, and application
Ying Luo, Fujian (CN); Jiaying Huang, Fujian (CN); Zongbo Liao, Fujian (CN); Qin Lan, Fujian (CN); Yulin Lin, Fujian (CN); Dawei Shi, Fujian (CN); Juhua Xie, Fujian (CN); and Yanqing Long, Fujian (CN)
Assigned to FUJIAN GOLDEN DRAGON RARE-EARTH Co., Ltd., Fujian (CN)
Appl. No. 17/785,044
Filed by FUJIAN GOLDEN DRAGON RARE-EARTH Co., Ltd., Fujian (CN)
PCT Filed Feb. 22, 2021, PCT No. PCT/CN2021/077178
§ 371(c)(1), (2) Date Jun. 13, 2022,
PCT Pub. No. WO2021/169893, PCT Pub. Date Sep. 2, 2021.
Claims priority of application No. 202010121798.0 (CN), filed on Feb. 26, 2020.
Prior Publication US 2023/0035214 A1, Feb. 2, 2023
Int. Cl. B22F 9/04 (2006.01); B22F 3/10 (2006.01); H01F 1/057 (2006.01)
CPC H01F 1/0577 (2013.01) [B22F 3/1017 (2013.01); B22F 9/04 (2013.01); B22F 2009/044 (2013.01); B22F 2203/11 (2013.01); B22F 2302/05 (2013.01); B22F 2303/01 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A neodymium-iron-boron magnet material, which comprises the following components by mass percentage:
R: 28-33%; R comprises R1 and R2, R1 comprises Nd and Dy, R2 comprises Tb, the content of R2 is 0.2%-1%; the content of Dy in R1 is 0.05-0.3%;
Co: 0.05-0.45%;
M: ≤0.4%, but not 0, M is at least one element selected from group consisting of Bi, Sn, Zn, Ga, In, Au, and Pb;
Cu: ≤0.15%, but not 0;
B: 0.9-1.1%;
Fe: 60-70%;
C; and
O;
the percentage is the mass percentage of the mass of each component to the total mass of neodymium-iron-boron magnet material;
the neodymium-iron-boron magnet material comprises Nd2Fe14B grains and their shells, and two-grain intergranular boundary and grain boundary triangle region adjoining to the Nd2Fe14B grains; wherein, heavy rare earth elements in R1 are distributed in Nd2Fe14B grains, R2 is mainly distributed in the shell, two-grain intergranular boundary and grain boundary triangle region, the area proportion of the grain boundary triangle region is 1.9-3.15%; the continuity of the two-grain intergranular boundary is 96% or more; the proportion of the mass of C and O in the grain boundary triangle region is 0.4-0.5%, the proportion of the mass of C and O in the two-grain intergranular boundary is 0.3-0.45%; wherein, the continuity of two-grain intergranular boundary refers to the ratio of the length of a B rich phase, a rare earth rich phase, rare earth oxides and rare earth carbides in the grain boundary to the total length of the grain boundary;
the two-grain intergranular boundary further comprises a new phase with the chemical composition of Rx(Fe+Co)100-x-y-zCuyMz; wherein, R in the Rx(Fe+Co)100-x-y-zCuyMz comprises at least one element selected from Nd, Dy, and Tb; M is at least one element selected from Bi, Sn, Zn, Ga, In, Au, and Pb; x is 42-44; y is 0.2-0.4; z is 0.2-0.45.