Investigation of Corrosion Protection Performance of Sol-gel Coatings on AA2024-T3

摘要

The paper addresses the technologically important problem of replacement of chromate based coatings for corrosion protection of aircraft. The Air Force requires development of environmentally compliant aircraft coating systems that perform adequately in terms of corrosion protection. Current Air Force corrosion inhibitor paint chemistry relies heavily on the use of Cr(VI) compounds in the form of strontium or barium chromate, which are incorporated into both the surface pretreatment and the primers. These corrosion inhibitor systems are very effective, but are known carcinogens and therefore must be eliminated. To address this problem, sol-gel based surface treatments are being investigated as a potential replacement for the current chromate-based surface treatment. Experiments were performed to verify that sol-gel coatings can be used as barrier layers in complex coating systems. The results clearly demonstrated that epoxy-zirconate sol-gel coatings are a viable replacement for the currently used chromate-based surface treatments.