Permanent magnet and manufacturing method thereof
US9048014B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2011 |
| Grant date | Jun 2, 2015 |
| Priority date | — |
| Expiry date | Dec 7, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F41/0293
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
There are provided a permanent magnet and a manufacturing method thereof capable of decreasing an activity level of a calcined body activated by a calcination process. To fine powder of milled neodymium magnet is added an organometallic compound solution containing an organometallic compound expressed with a structural formula of M−(OR)x (M represents Dy or Tb, R represents a substituent group consisting of a straight-chain or branched-chain hydrocarbon, x represents an arbitrary integer) so as to uniformly adhere the organometallic compound to particle surfaces of the neodymium magnet powder. Thereafter, desiccated magnet powder is held for several hours in hydrogen atmosphere at 200 through 900 degrees Celsius. Thereafter, the powdery calcined body calcined through the calcination process in hydrogen is held for several hours in vacuum atmosphere at 200 through 600 degrees Celsius for a dehydrogenation process. Thereafter, through powder compaction and sintering process, the powdery calcined body is formed into a permanent magnet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.