THE ELECTROLYTIC COLOURING OF ANODIZED ALUMINUM BY MEANS OF OPTICAL INTERFERENCE EFFECTS

摘要

Anodized aluminium having an anodic oxide film of at least 3 microns thickness is colored by electrolytically depositing inorganic pigment from metallic salt solutions, particularly nickel, cobalt, tin and copper salts and mixtures. The pigment deposits are characterized by outer ends of an average size in excess of 260 A lying at a distance of 500 - 3000 A from the aluminium/aluminium oxide interface.