Finite Element Modeling of Chemical and Electrochemical Protection Mechanisms Offered by Mg-Based Organic Coatings to AA2024-T351

A finite element model of the protection mechanisms offered by Mg-based organic coatings was developed. The predicted change in corrosion potential AA2024-T351 as a function pH, water layer thickness, and inhibition oxygen reduction reaction. pH solution calculated taking into account Mg dissolution, precipitation Mg(OH) 2 , Al hydrolysis 3+ ions. critical value at which sharply decreases to values below pitting pit repassivation potentials under full immersion conditions accordance with experimental observations. limiting thickness pH-induced mechanism is not occur calculated. If reaction considered, becomes feasible thinner layers. Cathodic Mg-rich primers modeled coating resistance, electrolyte chemistry. magnitude resistance film pigments are embedded mitigates extent cathodic protection. local due reactions affected galvanic obtained. framework developed can be used help identify chemical inhibitors that operate mode described this work.