Rare earth permanent magnet and production method thereof
US6159308A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1998 |
| Grant date | Dec 12, 2000 |
| Priority date | — |
| Expiry date | Dec 11, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0577
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of producing an R--Fe--B-based, sintered permanent magnet, wherein R is at least one rare earth element including Y, having a small oxygen content. A coarse alloy powder prepared by a reductive diffusion method is milled and recovered into a solvent to form a slurry. The slurry is wet-compacted to form a green body which is then sintered after removing the solvent. The milling, recovering, wet-compacting, solvent-removing and sintering steps are carried out while preventing the powder, slurry and green body from being brought into contact with air to minimize the oxygen content in the final sintered permanent magnet. The sintered permanent magnet produced has a high density and a high magnetic properties due to a low oxygen content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.