Method for forming Fe-B-R-T alloy powder by hydrogen decrepitation of die-upset billets
US5143560A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 20, 1990 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Apr 20, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0578
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for the high volume manufacture of Fe-B-R-T alloy powders without sacrificing the resultant magnetic properties (such as intrinsic magnetic coercivity) of the alloy involves hydrogen decrepitation of vacuum cast or die-upset billets of the alloy. Hydriding is carried out at a partial pressure of hydrogen of between 250 and 760 mm Hg at 100.degree. to 500.degree. C. for 30 minutes to 6 hours or longer, depending upon load size. Dehydriding occurs in a vacuum below 10.sup.-2 mm Hg or in an inert atmosphere possessing a partial pressure of hydrogen below 10.sup.-2 mm Hg. The alloy powder is preferably incorporated in matrix or composite magnets by the addition of a binder prior to pressing and orienting. The binder may set during pressing in a hot die, or by heating after pressing in a cold die.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.