Inhibition Probing on a Cut-Edge Electrode Machined from a Primer-Coated 2024-T3 Alloy

Conventional corrosion protection of 2024-T3 alloys (AA2024T3) in aeronautic structures combines conversion coating with chromate-inhibited primer protected by a top-coat. In some cases this protection can break down after mechanical damage to the paint systems inducing a risk of localized corrosion if the release of inhibitors trapped in the primer does not reach a critical level. There is a need for developing computational models combining the inhibitor release and transport within and from the coating system andthecorrosioninhibitionprocess,toassistinthedesignofnewmultifunctionalcoatingsystems.Theinfluenceonthecorrosioninhibition of various parameters such inhibitor release rate, defect geometry, waterlayerthickness,chlorideconcentrationmustbeinvestigatedasthey will represent the boundary conditions of the model. Few studies can be found in literature covering the competition between the inhibitor release from the paint and the corrosion of the bare metal surface after a scratch. 1