Fabrication of a super-hydrophobic sealing silane film with anti-corrosion, wear-resistant and self-cleaning properties via electrodeposition on a micro-arc oxidized aluminum alloy

Abstract

Micro-arc oxidation (MAO) has gained widespread adoption in aluminum alloy protection due to their remarkable corrosion resistance. Nevertheless, the inherent microporous defects of MAO layer persist in exposing the substrate to corrosive damage during operational conditions. While silane-based sealing techniques have emerged as a promising solution for these defects, their practical implementation still faces critical challenges including insufficient defect-filling capacity and compromised mechanical durability. The present work employs electrochemical-assisted method that selectively generates hydroxyl/hydroxide ions at microporous defect sites within the MAO layer. Such local alkalinization conditions enable the directed assembly of silane hydrolysis products, driving interfacial adhesion-condensation reactions to achieve in situ silane film deposition with spatial selectivity. The optimized sealing system demonstrates a 50 % improvement in long-term corrosion resistance (150 MΩ·cm²) compared to conventional impregnation methods, accompanied by significantly enhanced self-cleaning, wear-resistant property. This provides a solution for the multifunctional anti-corrosion, wear-resistant, self-cleaning of aluminum alloy surfaces.