Powder magnetic core, method of manufacturing powder compact for magnetic core, die and die assembly for manufacturing powder magnetic core, and die lubricating composition for manufacturing powder magnetic core
US9754710B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2014 |
| Grant date | Sep 5, 2017 |
| Priority date | — |
| Expiry date | Sep 25, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C2202/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The compact for a magnetic core is manufactured by filling a soft magnetic powder in the die hole, pressing it to form a compact at a density ratio of the soft magnetic powder being 91% or more, and extruding it from the die hole. Before filling the soft magnetic powder to the die hole, a lubricating coating containing lubricating oil and molybdenum disulfide particles is formed on the inner surface of the die hole. It is more effective when further containing insulating ceramic particles. On the extrusion-sliding surface, the compact has a surface layer of the structure that molybdenum disulfide particles and the insulating ceramic particles are interposed between the soft magnetic powder particles, and insulation of soft magnetic powder particles in the surface layer is not destroyed by extrusion. This provides a powder magnetic core suitable for high frequency application.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.