Inhibitor for aqueous liquid deoxidizing composition and process for aluminum, with reduced etching of titanium
US5637252A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1996 |
| Grant date | Jun 10, 1997 |
| Priority date | — |
| Expiry date | Jan 29, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23G1/125
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A chromium-and-ferricyanide non-aqueous cleaner/deoxidizer for aluminum, the cleaner/deoxidizer having an etch rate on titanium that is low enough for practical use in processes where aluminum objects to be deoxidized are held on titanium racks or hangers during the process, combines boric acid, fluoborate anions, and an acid that is stronger than either of boric and fluoboric acids, usually also with an oxidizing agent such as hydrogen peroxide. Rates of etching of aluminum that are at least as much as 50 times the rates of etching of titanium under the same conditions can be achieved, and the deoxidizing of the aluminum is satisfactory for achieving corrosion resistance after subsequent conversion coating of the deoxidized aluminum surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.