Characterization of the Anodic Film and Corrosion Resistance of an A535 Aluminum Alloy after Intermetallics Removal by Different Etching Time

The objective of this study was to improve the corrosion resistance an A535 alloy by removing intermetallics on surface alkaline etching morphologies and properties anodic film that sealed with different sealants. It found for 4 min suitable dissolving intermetallic particles simultaneously providing sufficient roughness adhesion oxide Al matrix. effect revealed a decrease in fraction from 21% 16% after 2 min, respectively, corresponded increase roughness, thickness, consistency film. also demonstrated morphology films stearic acid sealing more uniform compact than nickel fluoride sealing. electrochemical polarization curves salt spray test proved etched had better as compared aluminum fluoride.