Study on the Influence of Aluminum Alloy Surface Roughness on Paint Adhesion

At present, the environmental tolerance assessment of aviation products is more stringent, so the demand for products to tolerate harsh environments is higher. In this study, the matte enamel coating of 6061 aluminum alloy and fluoropolyurethane was taken as the object, and the effect of different surface roughness and different painting processes on the adhesion of the paint film surface was explored by experimental methods. The samples with different roughness were prepared by sandblasting （glass sand, brown corundum） and magnetic grinding （polishing needle）, and through vibration test and coating adhesion test, it was found that the adhesion of the paint layer was not positively correlated with the surface roughness. From the microscopic point of view, the grooves and pits on the rough surface can be used as mechanical anchoring points for painting the paint film, and the contact area of the paint film can be increased, thus increasing the adhesion and firmness of the paint film. This conclusion can provide a basis for the optimization of aluminum alloy painting technology.