Rare earth anisotropic magnetic materials for polymer bonded magnets
US5470400A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1994 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | May 31, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/059
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention relates to a process for producing a non-pyrophoric, corrosion resistant rare earth-containing material capable of being formed into a polymer bonded permanent magnet comprising forming particles from a rare earth-containing alloy, and treating the alloy with a passivating gas comprised of nitrogen, carbon dioxide or a combination of nitrogen and carbon dioxide at a temperature below the phase transformation temperature of the alloy, and heat treating the alloy to produce material having a coercivity of at least 1,000 Oersteds. Rare earth-containing alloys suitable for use in producing magnets, such as Nd--Fe--B and Sm--Co alloys, can be used. If nitrogen is used as the passivating gas, the resultant powder particles have a nitrogen surface concentration of from about 0.4 to about 26.8 atomic percent. Moreover, if carbon dioxide is used as the passivating gas, the resultant powder particles have a carbon surface concentration of from about 0.02 to about 15 atomic percent. The particles made in accordance with the present invention are capable of being aligned by a magnetic field to produce an anisotropic polymer bonded permanent magnet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.