Preparation of multifunctional protective coatings on low-carbon steel surfaces via micro-arc oxidation and self-assembled monolayer technology

A composite protective system integrating micro-arc oxidation (MAO) with self-assembled monolayer (SAM) technology was developed to improve the self-cleaning, corrosion, and wear resistance of low-carbon steel in marine environments. The microstructure and elemental distribution of the MAO coating were analyzed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), while the bonding mechanisms between Hexadecyltriethoxysilane (HDTES) and the MAO substrate were examined via X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The superhydrophobic coating exhibited a static contact angle of 159.6° and a sliding angle of 7.5°, maintaining a contact angle of 142° after 50 friction cycles. Friction tests revealed a low coefficient of friction and a reduced wear rate. Electrochemical measurements demonstrated a corrosion current density of 1.30 × 10 −8 A/cm 2 and a corrosion rate of 0.00015 mm/y. The composite coating demonstrated excellent superhydrophobicity, mechanical durability, wear resistance, and corrosion resistance, offering an effective solution for metal protection in harsh environments.