Aluminum-polyethylene composite coatings with self-sealing induced anti-corrosion performances

Abstract Aluminum (Al) based coatings fabricated using arc spraying are usually employed as anti-corrosion coatings in the marine environment, coupled with post-treated sealing on their surfaces. In this investigation, ultra-high molecular weight polyethylene (UHMWPE) particles were added in Al coatings using cored wire arc spraying, in which UHMWPE were employed as sealants, instead of post-sealing treatment. The microstructures of in-flight particles and singly deposited particles were characterized to reveal microstructure evolution mechanisms of cored wires. The microstructures of composite coatings were also analyzed to discuss the self-sealing mechanism of UHMWPE particles. Neutral salt spraying and electrochemical analysis were employed to reveal corrosion thermodynamics and kinetics of composite coatings. The results show that UHMWPE particles presented two structures in composite coatings. The melted UHMWPE thin films sited at the interfaces of Al particles, played as sealants, contributing to the increase of corrosion resistance. Incompletely melted UHMWPE particles also existed in composite coatings, due to the protective effect of Al-UHMWPE core-shell structures formed in spraying. The strategy fabricating Al-UHMWPE composite coatings gives bright insight into a new route to develop marine self-sealing induced anti-corrosion coatings.