A High-temperature and corrosion-resistant Co-Al2O3 composite superhydrophobic coating for marine exhaust emission systems

To address the challenges of high-temperature corrosion in marine exhaust systems this study utilizes a one-step electrodeposition technique to fabricate a superhydrophobic Co-Al 2 O 3 composite coating on low-carbon steel. A comprehensive analysis was conducted to examine the coating’s surface morphology, hydrophobic characteristics, self-cleaning capability, corrosion resistance, and thermal stability. The results demonstrated that the composite coating exhibited remarkable hydrophobicity, with a contact angle (CA) of approximately 163.7°. Furthermore, after heating to 500 °C, the coating maintained superior corrosion resistance, achieving a corrosion protection efficiency ( η ) of 89.8 % in a 3.5 wt % sodium chloride solution. Electrochemical impedance spectroscopy (EIS) revealed that the coating effectively suppressed electrochemical reactions, thus prolonging the protection of the metal surface. These findings suggest that the Co-Al 2 O 3 composite coating provides potential protective capabilities for metals in marine environments, making it suitable for high-temperature corrosion resistance in gas turbines. This approach has the potential to extend equipment lifespan and reduce maintenance costs.