Influence of surface properties on interfacial compatibility between coating and substrate

Abstract

The surface properties of the substrate is one of the fundamental and important factors affecting the interfacial compatibility of waterborne rust repair coatings with aluminium alloy substrates. This paper analyses the effect of the composition and structural characteristics of corrosion products on the surface of corroded aluminum alloys on the interfacial compatibility of coatings with the substrate by means of laser confocal, scanning electron microscopy (SEM), Raman, contact angle testing, electrochemical impedance spectroscopy (EIS) and adhesion testing. The results indicate that the corrosion products on the aluminum alloy surface consist of β-Al(OH)₃, γ-AlOOH, and AlCl₃ layers. These corrosion products facilitate the infiltration and accumulation of corrosive media, thereby accelerating coating degradation. As the corrosion duration increases, the protective capability of the coating diminishes, leading to significant interfacial delamination. The oxide film formed on the chemically anodized treatment effectively prevents further penetration of corrosive media, thereby enhancing the corrosion resistance of the coating and reducing the extent of interfacial debonding. This paper examines the influence of substrate surface properties on the interfacial compatibility between waterborne rust repair coatings and aluminum alloys, providing foundational guidance for the development of waterborne rust repair coatings tailored for aluminum alloys.