Method of producing light absorptive surface on aluminum zinc alloy coated product
US4479832A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1982 |
| Grant date | Oct 30, 1984 |
| Priority date | — |
| Expiry date | May 12, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
This invention is directed to a method for producing a corrosion-resistant, composite product, such as sheet and strip, having a thin, uniformly black, light-absorptive surface layer thereon, and to the product of such method. The method includes the steps of treating a product having a coating containing both zinc and aluminum, such as galvanized strip, or up to 70% by weight, aluminum, balance essentially zinc coated strip, with an aqueous alkaline solution for a sufficient time to form a zinc-rich surface on said product, which surface is reactive with a blackening bath containing Ni and Sb, and subjecting such treated product to such blackening bath to form said thin, uniform, light-absorptive surface layer on said product. The light-absorptive surface layer has a thickness of at least 80 nm, preferably between about 100-400 nm, and an absorptance greater than about 95% over the solar radiation spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.