Non-chromated surface preparation materials and methods for corrosion protection of aluminum and its alloys
US5693153A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1996 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Nov 21, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C22/68
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Surface preparation methods and materials that provide corrosion protection for aluminum and its alloys without the use of chromate and that protects aluminum surfaces against corrosion nearly as well as a chromate conversion coating. In accordance with the present methods, aluminum parts are degreased in a general purpose cleaner and rinsed in hot tap water. The parts are then cleaned using alkaline cleaner and then rinsed in cold tap water. The parts are then deoxidized using one of two alternative steps. The parts may be deoxidized using a 20-25 volume percent Smut-Go NC solution at room temperature for 15-25 minutes. The parts may alternatively be deoxidized using a solution of 10% HNO.sub.3 and 3% NaBrO.sub.4 dissolved in water at room temperature for 15-25 minutes. The deoxidized aluminum parts are then rinsed in cold tap water. The parts are then immersed in boiling deionized water and then sealed using a 1% LiNO.sub.3, 10% Al(NO.sub.3).sub.3 and 10% aluminum silicate solution. The sealed parts are sealed a second time using a solution of 13-15% Kasil #1 with a dissolved corrosion inhibitor. The sealed parts are finally dried in air for about 24 hours or in an oven for 3-4 h…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.