Microstructure and properties of oxalic acid-citric acid anodized film on 6063 aluminum alloy

摘要

This study focuses on the widely used 6063 aluminum alloy in the industrial field, using oxalic acid and citric acid solutions as electrolytes to investigate the influence of oxalic acid concentration on the structure, wear resistance, and scale inhibition performance of the anodic oxide film. The phase composition of the oxide film was characterized by X-ray diffraction, and the microstructure of the oxide film was observed using scanning electron microscopy. Additionally, the corrosion resistance and scale inhibition performance of the anodic oxide film were tested. The research results show that the anodic oxide film is mainly com posed of Al 2O3 and exhibits a nanoporous structure when prepared with three different electrolyte concentrations. In particular, the oxide film prepared with 7.5% oxalic acid and 4% citric acid as electrolytes showed the best corrosion resistance, with a c orrosion rate of 0.0030 g/(m2· d) after 480 hours of salt spray test, which is only 1/11 of the 6063 aluminum alloy substrate 0.0321g/(m2· d). After 576 hours of immersion test, the corrosion rate of the oxide film was 0.458 mg/(dm2· d), while the corrosion rate of the aluminum substrate was 2.900 mg/(dm2· d), approximately 6 times that of the oxide film.