Highly corrosion-resistant rare-earth-iron magnets
US5154978A · kind A · utility
27Cited by
8References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1990 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Mar 22, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A highly corrosion-resistant rare-earth-iron magnet has a paraxylylene polymer film or a chloropara-xylylene polymer film formed thereon. The substrate magnet surface has a roughness Ra of no more than one micron. The magnet has a plasma polymer film formed beforehand or afterwards. The plasma polymer film has a protective film consists of only carbon and hydrogen, with a refractive index decreasing from the boundary surface between the film and the magnet toward the exposed surface. The protective coating has a thickness about three times the surface roughness of the substrate magnet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.