Analyses of Rough Point Defects on 6063 Aluminum Alloy in Anodizing Process

The rough points on 6063 aluminum alloy formed in its anodizing process were analyzed by means of surface morphology analysis, microstructure analysis, SEM and EDS. The results showed that the rough point formed defect in the anodizing process was pitting corrosion, resulting from the selective corrosion of free Si, intermetalic compounds, superfluous Zn, etc, and rapid dissolution of aluminum alloy activated by Cl-. The corrosion resistance of aluminum alloy with rough points will be reduced remarkably.