Effects of graphene on structure and corrosion resistance of plasma electrolytic oxidation coatings formed on D16T Al alloy

Abstract Plasma electrolytic oxidation (PEO) coatings were fabricated on D16T Al alloy in the silicate electrolyte with and without graphene. The microstructure, phase composition, elemental distribution, micro-hardness, thickness and corrosion resistance of PEO coatings were investigated. Results showed that PEO coatings formed in the electrolyte with graphene exhibited unexceptionable corrosion resistance because incorporated graphene made PEO coatings flatter, denser, compacter and harder. Graphene successfully embedded into PEO coatings remarkedly decreased micropores and microcracks of the PEO coating, and significantly enhanced the corrosion resistance of the PEO coating produced on D16T Al alloy due to its physical separation.