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This post was last edited by Wang Wei2 on 2026-4-19 at 10:23. Metal surface treatment has a significant impact on the properties of composite coatings, affecting aspects such as adhesion, corrosion resistance, mechanical properties (such as impact resistance and flexibility), and surface morphology. 1. Key mechanism of action: Improving adhesion: Surface treatment (such as sandblasting, phosphating, and pickling) removes contaminants such as oil and oxide scales, increasing the roughness of the substrate; this in turn enhances the mechanical interlocking and chemical bonding between the coating and the substrate. Improving corrosion resistance: Pre-treatments such as phosphating, zirconium treatment, and anodizing can form dense conversion coatings that prevent corrosive agents from penetrating, thereby significantly increasing the salt spray resistance time of the composite coating. 2. Optimization of mechanical properties: Sandblasting can improve the impact resistance of the coating (due to increased surface roughness, which enhances mechanical interlocking) ； However, the phosphating film is highly brittle, which may reduce the flexibility and bend resistance of the coating. 3. Regulation of surface morphology: The treatment process determines the surface roughness and microstructure of the substrate, which in turn affects the uniformity, porosity, and quality of the bonding interface of the composite coating. 4. Special considerations for composite coatings: In cerametallic composite coatings or self-lubricating composite coatings (such as MoS₂/Ti), surface pretreatment is even more crucial ； Inadequate oxidation or cleaning can result in a membrane layer with many pores and weak bonding ； Appropriate preloading treatment or an active oxide layer can increase the coating adhesion strength by over 100%.