Accession Number:

ADA099995

Title:

Multicomponent Oxide Systems for Corrosion Protection.

Descriptive Note:

Final rept.,

Corporate Author:

AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS

Personal Author(s):

Report Date:

1980-11-15

Pagination or Media Count:

98.0

Abstract:

The formation and function of corrosion-resistant surface oxide films on aluminum have been investigated during a three-year research effort. Mixed oxide coatings should, based on a conceptual model, offer superior corrosion resistance a mixed oxide is defined as an oxide system based on more than one cation species. The structures of the mixed oxide coatings studied were characterized using Auger electron spectroscopy, x-ray photoelectron spectroscopy, and ion microprobe mass analysis. Corrosion resistance was assessed by exposing specimens in a salt chamber. Chromate coating systems, long in use on aluminum, were examined first to provide a standard against which to measure coating performance. Chromate coating formation was explained in terms of the role of hydrogen fluoride or hydroxyl ion in the dissolution of the native aluminium oxide layer and through the influence of the slight solubility difference between chromium and aluminum hydroxides on film growth. New types of mixed oxide coatings deposited from nonaqueous solutions of organometallic compounds were developed. Titanium-aluminum mixed oxide coatings, deposited from solutions of titanium alkoxides in isopropanol, served as a prototype system for much of this work. It was found that the application of certain sulfur compounds in conjunction with titanate coatings resulted in enhanced corrosion resistance, and in one case AA 6061, the corrosion resistance exceeded that of the chromate coatings. The feasibility of the basic approach taken here has been validated. It remains for future work to effect further improvements in the technique. Author

Subject Categories:

  • Coatings, Colorants and Finishes

Distribution Statement:

APPROVED FOR PUBLIC RELEASE