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 metal salt, the oxide film on the article can be colored in a stable manner and in a deep color by applying repeatedly, after subjecting the article to a cathodic direct current electrolysis in an electrolytic coloring bath containing the metal salt, an anodic direct current electrolysis and then further a cathodic direct current electrolysis to the article.