Method of improving the coercivity of Nd—Fe—B magnets
US11114237B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 2018 |
| Grant date | Sep 7, 2021 |
| Priority date | — |
| Expiry date | Sep 6, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C2202/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of improving coercivity of an Nd—Fe—B magnet includes a first step of providing an Nd—Fe—B magnet having a first surface and a second surface. Next, a first solidified film of at least one pure heavy rare earth element is formed and attached to the first surface of the Nd—Fe—B magnet to prevent a reduction in corrosion resistance caused by oxygen and fluorine and hydrogen. After forming the first solidified film, the Nd—Fe—B magnet is subjected a diffusion treatment in a vacuum or an inert atmosphere. After the diffusion treatment, the Nd—Fe—B magnet is subjected to an aging treatment in the vacuum or the inert atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.