The aim of this work is to develop a glass-like CexOy coating to seal the pores of a Flash-PEO coated AZ31B Mg alloy and simultaneously provide smart self-healing corrosion protection.The cerium sol was synthesized using cerium acetate as main precursor by sol-gel method.SEM micrographs revealed that upon cerium sol deposition, the pores of the oxide coating were effectively sealed, resulting in a double-layer coating Soft Toy system and thereby in a big reservoir of cerium ions (Ce3+/Ce4+).The glassy character of the cerium coating, confirmed by X-Ray diffraction, implies that cerium exists in Ce3+ and Ce4+ ionic states enclosed in a high internal energy structure which facilitate the diffusion of cerium ions to active cathodic zone.
Electrochemical Impedance Spectroscopy (EIS), X-Ray Diffraction (XRD), and Raman spectroscopy were used to explore the active corrosion protection of the CexOy sol-gel coating.The corrosion inhibition mechanism involves the migration of Military Helicopter cerium ions and the precipitation of insoluble-crystalline cerium compounds (CeO2).The coating demonstrated self-healing properties, presenting a promising alternative to traditional chrome conversion coatings (CCC).