(98k) Modeling of Inhibitor Diffusion in a Coating System

Aluminum alloys have long been the favored material for airplane skins due to their strong yet lightweight nature. While these alloys are naturally resistant to uniform corrosion, they are subject to pitting corrosion. Hexavalent Chromium, Cr(VI), is often used for corrosion inhibitor as part of a protective coating. While the inhibition performance of Cr (VI) is effective, it has been proven to be both a carcinogen and harmful to the environment. Its harmful effects have produced consumer and governmental pressure to replace it or, at the minimum, to reduce its use. In order to develop a suitable replacement, the coatings industry must develop a better understanding of the underlying mechanism behind the inhibition behavior of Cr(VI). This work focuses on developing a model for the diffusion of processes associated with inhibition.