Process for electrolytic coloring of the anodic oxide film on aluminum or aluminum base alloys

摘要

In the process of coloring an anodized aluminum or aluminum alloy article by subjecting the anodized article to an electrolytic treatment with a direct current in an aqueous electrolytic coloring bath containing a water-soluble metallic salt, the oxide film on the article can be easily colored in a stable manner and in a uniform color, by subjecting the anodized article previously to an anodic direct current electrolysis in an aqueous solution containing the same metallic ion as in the coloring bath, and then to a cathodic direct current electrolysis for coloring the anodized oxide film on the article.