Electrolytic coloring process for aluminum material

Abstract

The invention relates to an electrolytic coloring process for an aluminum material, and belongs to the field of aluminum material surface treatment. The electrolytic coloring process comprises the following steps of: carrying out first-time anodic oxidation treatment on the pretreated aluminum material, and forming an anodic oxidation film with the thickness of 4-8 microns on the surface of the aluminum material; carrying out second-time anodic oxidation treatment on the aluminum material, and enabling the thickness of the film to be greater than 10 microns; carrying out first-time electrolytic coloring treatment on the aluminum material in a silver salt electrolytic coloring solution, wherein the silver salt electrolytic coloring solution comprises AgNO3 with the concentration of 1g / L andH2SO4 with the concentration of 20g / L; and carrying out second-time electrolytic coloring treatment on the aluminum material in a nickel-tin mixed salt electrolytic coloring solution, wherein the nickel-tin mixed salt electrolytic coloring solution comprises NiSO4 with the concentration of 8-12g / L, SnSO4 with the concentration of 10-15g / L and H2SO4 with the concentration of 15-20g / L. Through twotimes of anodic oxidation treatment, the requirements of a subsequent electrolytic coloring process on the thickness of the film are met; and through two times of electrolytic coloring treatment, thecolor of the film is transited from a brass color as a bronze color system to a bronze color with uniform and stable color, so that the bronze color system is expanded.

Description

technical field [0001] The invention belongs to the field of aluminum material surface treatment and relates to an aluminum material electrolytic coloring process. Background technique [0002] Electrolytic coloring is the AC electrolysis of anodized aluminum and its alloys in an aqueous solution containing metal salts, depositing metals, metal oxides or metal compounds on the bottom of the porous layer of the oxide film, due to the scattering of light by the electrodeposits. Presents a variety of colors, and its advantage is that the obtained colored film has good wear resistance, light resistance, heat resistance and chemical corrosion resistance. [0003] The industrialized electrolytic coloring solutions at home and abroad are basically nickel salts or tin salts or nickel-tin mixed salts, and the color of the obtained coloring film is generally from light to dark bronze color system, and the color is relatively single. Contents of the invention [0004] In view of thi...

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Problems solved by technology

[0004] In view of this, the purpose of the present invention is to provide an aluminum electrolytic coloring process, which solves the problem that the current aluminum electrolytic coloring is mostly limited to the bronze color system, and the color is relatively single

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