Method of preparing a magnetic material
US4715890A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1986 |
| Grant date | Dec 29, 1987 |
| Priority date | — |
| Expiry date | Oct 17, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F9/24
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of forming a magnetic material. The magnetic material is a solid mass of grains, and has magnetic parameters characterized by: (1) a maximum magnetic energy product, (BH).sub.max, greater than 15 megagaussoersteds; and (2) a remanence greater than 8 kilogauss. The magnetic material is prepared by a two step solidification, heat treatment process. The solidification process is carried out by: (a) forming a solution of reducible precursor compounds of the magnetic material; and (b) thereafter reducing the reducible, precursor compounds and forming a precipitate thereof. The precipitate has a morphology characterized as being one or more of (i) amorphous, (ii) microcrystalline, or (iii) polycrystalline. The grains within the precipitate have, at this stage of the process, an average grain characteristic dimension less than that of the heat treated magnetic material. In the second, or heat treating, stage of the process, the precipitated solid is heat treated to form a solid material comprised of grains meeting at grain boundaries. The grains and grain boundaries have the morphology of the magnetic material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.