Multi-layer multi-metal electroplated protective coating
US4418125A · kind A · utility
Inventor
Key dates
| Filing date | Dec 6, 1982 |
| Grant date | Nov 29, 1983 |
| Priority date | — |
| Expiry date | Dec 6, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1291
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
This invention is directed to the formation of highly protective electroplated multi-metal coatings over an iron basis metal. The high degree of protection is obtained by the deposition of three sucessive layers of two dissimilar metal layers that form a galvanic cell in which one of the two adjacent metals is anodic to the other so that the corroding anodic electroplate will spread the attack laterally and thus prevent the corrosive media from drilling through to the base metal. The coating comprises an initial layer of sulfur free nickel followed in sucession by a sulfur containing bright nickel, cadmium, copper, sulfur free nickel, sulfur containing nickel and microporous chromium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.