A Review of Metal Surface Modification and Performance Enhancement Based on Micro-Arc Oxidation Composite Technology

Composite coatings on metal surfaces are crucial for enhancing the overall service performance of engineering components, particularly for lightweight alloys (such as aluminum, magnesium, and titanium alloys) widely used in aerospace, marine engineering, and biomedical fields. However, in environments where multiple factors-such as wear, corrosion, and biofouling-interact, single-layer coatings often fail to meet performance requirements. MicroArc Oxidation (MAO), with its strong adhesion and porous ceramic structure, offers a promising platform for constructing multifunctional composite coatings. This paper first introduces the key technological framework for composite coatings on metal surfaces, then reviews their performance in terms of wear resistance, corrosion resistance, and antibacterial properties, and summarizes recent preparation strategies, microstructures, and performance enhancement mechanisms. Research indicates that rational composite design can synergistically enhance the overall performance of coatings; however, it is essential to balance the trade-offs between performance characteristics (such as hardness versus toughness, and wear resistance versus corrosion resistance). Future research should focus more on green processes, smart responsive coatings, and the use of computational simulations to guide efficient coating design and optimization.