Method of producing R-Fe-B permanent magnet, and lubricant agent and release agent for use in shaping the same
US6361738B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2000 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Mar 28, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F1/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The method of producing an R—Fe—B magnet of the present invention is characterized in that R—Fe—B alloy fine powder is molded in a magnetic field and sintered using a lubricant for molding magnets containing specific components, individually or as a mixture, of specific amounts of methyl caproate and/or methyl caprylate, which provide high crystal orientation, and lubricant comprising depolymerized polymer for improving molded article strength, or a lubricant for molding magnets wherein Ti coupling agent that improves crystal orientation is added to this lubricant for molding magnets. Each particle of the fine powder has a high degree of crystal orientation in the direction of the magnetic field, and molded article strength is markedly improved, leading to improved mass-productivity and yield. Moreover, the above-mentioned lubricants do not react with this magnet powder during sintering and are emitted as a gas. Therefore, binder removal performance is excellent and as a result, an increase in the amount of C remaining in the sintered compact is inhibited, to obtain an R—Fe—B permanent magnet with high Br and iHc properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.