Process for electrolytically coloring aluminum and aluminum alloys
AssigneeYoshida Kogyo K.K.
InventorsMutsuo Hasegawa, Kazuo Aikawa, Katsuyuki Nagata
Life of this patent
Estimating the term…
Abstract
Aluminum or aluminum alloy is first anodized to form an oxide film thereon. With the pores in this oxide film unsealed, the basis metal is then electrolyzed by use of alternating current at a preselected starting voltage, and this voltage is lowered at least once before completion of the electrolytic coloring of the basis metal. The electrolytic solution in which the electrolysis is effected contains either at least three metallic salts or at least two metallic salts and a strong reducing compound.
Claims7
A process for electrolytically coloring aluminum or aluminum alloy which comprises anodizing a desired basis metal, and electrolyzing the anodized basis metal in an acidic aqueous electrolyte by use of a constantly applied alternating current, the voltage at which the anodized basis metal is electrolyzed being lowered at least once by a value of from about 1 to 10 volts but not to a sustained zero potential in the course of the electrolysis.
Dependencies are inferred from the claim text.