US 11,657,933 B2
Manufacturing method of sintered magnet, and sintered magnet
Ikjin Choi, Daejeon (KR); Jung Goo Lee, Daejeon (KR); Juneho In, Daejeon (KR); Soon Jae Kwon, Daejeon (KR); Hyounsoo Uh, Daejeon (KR); Jinhyeok Choe, Daejeon (KR); Ingyu Kim, Daejeon (KR); and Eunjeong Shin, Daejeon (KR)
Assigned to LG Chem, Ltd.
Appl. No. 16/614,426
Filed by LG Chem, Ltd., Seoul (KR)
PCT Filed Nov. 28, 2018, PCT No. PCT/KR2018/014849
§ 371(c)(1), (2) Date Nov. 18, 2019,
PCT Pub. No. WO2019/107929, PCT Pub. Date Jun. 6, 2019.
Claims priority of application No. 10-2017-0160623 (KR), filed on Nov. 28, 2017; and application No. 10-2018-0135441 (KR), filed on Nov. 6, 2018.
Prior Publication US 2020/0203068 A1, Jun. 25, 2020
Int. Cl. H01F 1/057 (2006.01); B22F 3/10 (2006.01); C22C 38/00 (2006.01); C22C 38/16 (2006.01); H01F 41/02 (2006.01); B22F 1/142 (2022.01)
CPC H01F 1/0572 (2013.01) [B22F 1/142 (2022.01); B22F 3/10 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/16 (2013.01); H01F 1/057 (2013.01); H01F 1/0577 (2013.01); H01F 41/0293 (2013.01); B22F 2301/355 (2013.01); C22C 2202/02 (2013.01)] 8 Claims
 
1. A manufacturing method of a sintered magnet, the method comprising:
mixing neodymium iron boron (NdFeB)-based powders and rare-earth hydride powders to prepare a mixture;
heat-treating the mixture at a temperature of 600 to 850° C. for a time period sufficient to separate the rare-earth hydride powders into rare earth metals and hydrogen (H2) gas and to remove the H2 gas; and then
sintering the heat-treated mixture at a temperature of 1000 to 1100° C. to prepare the sintered magnet,
wherein the rare-earth hydride powders are neodymium hydride (NdH2) powders or mixed powders of NdH2 and praseodymium hydride (PrH2).