公开(公告)号：US11830645B2

公开(公告)日：2023-11-28

申请号：US16732426

申请日：2020-01-02

Applicant: ABB Schweiz AG

Inventor： Reinhard A. Simon ,  Jacim Jacimovic ,  Lorenz Herrmann ,  Tomaz Tomse

IPC: H01F1/00 ,  B22F3/10 ,  H01F7/02 ,  H01F41/00 ,  H01F1/053 ,  H01F1/057 ,  H01F41/02

CPC classification number: H01F1/0536 ,  B22F3/10 ,  H01F1/0577 ,  H01F7/02 ,  H01F41/0293

Abstract: A manufacturing method of a sintered magnet is described. The method includes forming a pre-sintering body from a first magnetic powder and a second magnetic powder (containing a heavy rare earth element, HRE) so that at least part of the second magnetic powder is provided at at least one inner portion of the pre-sintering body and surrounded format least two opposite sides by the first magnetic powder; sintering the pre-sintering body; and annealing the sintered pre-sintering body at an annealing temperature lower than the sintering temperature, thereby causing inter-grain diffusion of HRE from the HRE reservoir zone to the grain boundary phase. After the annealing, the grain boundary phase contains the HRE in a higher concentration than the main phase.