Hexagonal ba-ferrite sintered magnet, its making method, and polar anisotropy ring magnet
US5607615A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | May 11, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/2683
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In a method for preparing a magnet by pulverizing a calcined powder of hexagonal barium ferrite, compacting the thus pulverized ferrite magnet source particles in a magnetic field, and sintering the compact, a structure comprising barium ferrite as a primary phase and containing strontium and silicon as grain boundary components is obtained when a silicon component such as SiO.sub.2 and a strontium component such as SrCO.sub.3 are contained in the compact. This results in a hexagonal barium ferrite sintered magnet which has minimal anisotropy of shrinkage factor and minimal deformation during sintering, requires only simple or no post-polishing, and has improved sintered density and coercivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.