Comparative evaluation of cerium oxide primers electrodeposited on AA2024-T3 and D16 AM aircraft alloys

As a common practice, the metallic alloys are always protected by multilayer coating systems against environmental corrosive impact. The primer layers of these coating systems serve for improvement of the adhesion between the upper and finishing coating layers and the metallic substrate (cerium oxide primer (CeOP) layers). Furthermore, the structural and morphological features possessed by the coating primers strongly depend on the metallic surface roughness, and composition. In the present research work, cerium conversion coatings were electrodeposited on two different aircraft alloys, with identical chemical compositions (AA2024-T3, and D16 AM). The relation between the protective capabilities of the obtained layers and the structural features of the respective alloys was elucidated by electrochemical measurements, via linear voltammetry (LVA) and electrochemical impedance spectroscopy (EIS), combined with SEM/EDX observations.