Method of producing rare earth permanent magnet
US10490326B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 2, 2017 |
| Grant date | Nov 26, 2019 |
| Priority date | — |
| Expiry date | Nov 10, 2037 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2999/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed is a method of producing a rare earth permanent magnet including preparing a NdFeB sintered magnet, coating a surface of the NdFeB sintered magnet with a grain boundary diffusion material including R hydrate or R fluoride, and RaMb or M, to form a grain boundary diffusion coating layer, and diffusing the grain boundary diffusion material into a grain boundary of the NdFeB sintered magnet by heat treatment, wherein M is a metal having a melting point higher than a heat treatment temperature during the diffusion, R is a rare earth element, and a and b each represent atomic percentages which satisfy the following Equations (1) and (2): 0.1<a<99.9 (1)a+b=100 (2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.