Method of producing high performance permanent magnets
USRE32714E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1986 |
| Grant date | Jul 19, 1988 |
| Priority date | — |
| Expiry date | Apr 21, 2006 |
Classification
- Technology area (CPC —)General
Abstract
A method of producing .Iadd.permanent magnet material for .Iaddend.high performance permanent magnets is disclosed in which particles of a master alloy consisting of Fe.sub.2 B having a maximum particle size of 50 microns is admixed with Fe powder and particles of a rare earth capable of combining with Fe and B to form a tetragonal compound of Fe.sub.14 R.sub.2 B type. The admixture is compacted and a magnetic material is formed of the master alloy, Fe powder and .[.rate.]. .Iadd.rare .Iaddend.earth particles which includes a major phase of at least one intermetallic compound of the Fe-R-B type having a crystal structure of the substantially tetragonal system and while the particle size of the crystal structure is controlled by sintering the compacted admixture at a temperature of about 700.degree. C. to 1000.degree. C. for from a fraction of an hour to 36 hours. The magnetic material is then annealed at a temperature of about 550.degree. C. to 650.degree. C. for a fraction of an hour to 2 hours.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.