Corrosion protection properties of inhibitor containing hybrid PEO-epoxy coating on magnesium
By Yang, Junjie; Blawert, Carsten; Lamaka, Sviatlana V.; Snihirova, Darya; Lu, Xiaopeng; Di, Shichun; Zheludkevich, Mikhail L.
Published in Corrosion Science
2018
Abstract
A hybrid PEO-epoxy coating was developed for magnesium. A highly-efficient corrosion inhibitor (3-methysalicylate) was impregnated into the anodized layer, which was sealed by an epoxy layer through dip-coating process. Influence of dip-coating parameters on coating properties was investigated. The corrosion performance was evaluated through general and localized electrochemical techniques. As a result, the epoxy layers registered superior resistance, whereas the anodized layer suppressed corrosion expansion. Longer immersion and triple-dipping favored the production of better sealed epoxy layer. The active protection mechanism was achieved by suppression the re-deposition of detrimental impurity and/or adsorption upon the exposed surface from incorporated inhibitor.