ELECTROLYTIC COLORING METHOD OF ALUMINUM MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide an electrolytic coloring method of an aluminum material by which electrolytically colored aluminum material excellent in color tone uniformity can be industrially and easily manufactured. SOLUTION: In the electrolytic coloring method of the aluminum material, the aluminum material made of aluminum or an aluminum alloy subjected to an anodic oxidation film treatment is immersed in an electrolytic coloring treating bath containing soluble metallic salts and the aluminum material is subjected to AC electrolytic coloring treatment by energizing the aluminum material with AC wave form. Before AC electrolytic coloring treatment, current controlled coloring pretreatment in which DC is energized by regulating final voltage is executed in the electrolytic pigmentation treating bath with the aluminum material as an anode. Then successively AC electrolytic coloring treatment is executed in the same electrolytic coloring treating bath by energizing the aluminum material with voltage-controlled AC wave form having peak voltage of 0.55 to 0.8 times final voltage at the time of current controlled coloring pretreatment.