Rare-earth magnet and manufacturing method thereof and magnet motor
US7569114B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 2007 |
| Grant date | Aug 4, 2009 |
| Priority date | — |
| Expiry date | Jan 12, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The object of the present invention is to provide a rare earth magnet which enables to achieve a good balance between high coercive force and high residual magnetic flux density, and its manufacturing method. The present invention provides a rare earth magnet in which a layered grain boundary phase is formed on a surface or a potion of a grain boundary of Nd2Fe14B which is a main phase of an R—Fe—B (R is a rare-earth element) based magnet, and wherein the grain boundary phase contains a fluoride compound, and wherein a thickness of the fluoride compound is 10 μm or less, or a thickness of the fluoride compound is from 0.1 μm to 10 μm, and wherein the coverage of the fluoride compound over a main phase particle is 50% or more on average. Moreover, after layering fluoride compound powder, which is formed in plate-like shape, in the grain boundary phase, the rare earth magnet is manufactured by quenching the layered compound after melting it at a vacuum atmosphere at a predetermined temperature, or by heating and pressing the main phase and the fluoride compound to make the fluoride compound into a layered fluoride compound along the grain boundary phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.