Cerium oxides as alternative to chromate anticorrosion coatings

Coating systems used for military aircraft generally consist of a hexavalent chromium conversion coating in direct contact with the metallic substrate, followed by a strontium chromate primer, and a final resin topcoat over the primer.

A project was run to test the possibility of replacing the traditional three layer system with a two-layer system: a non-chromate conversion coating and a self-priming coating that incorporates nontoxic corrosion inhibitors. Cerium oxide was found to be a potentially viable corrosion inhibitor and replacement for chromate conversion coatings on aluminum alloys.