A comparative study of corrosion performance of sealed anodized layers of conventionally colored and interference-colored aluminium

The nanostructure of aluminium anodized layer was modified in phosphoric acid to induce light-interference colors through electrocoloring using nickel pigments. After a mixed sealing procedure, the corrosion performance of the interference-colored anodized layer was evaluated using Tafel polarization and electrochemical impedance spectroscopy. The results were compared with those obtained for conventionally colored anodized layer. The modification made the mixed sealing of subsequent colored layer less effective. The steam-sealing was found to be more effective for sealing the interference-colored anodized layer. For effectively sealed layers, the porous layer plays an additional role besides the barrier layer in determining the corrosion performance.