CONDUCTIVITY ANODIZING METHOD

• Main Author: KIM, GWANG SU
• Format: Patent
• Language: English
• Published: 16.01.2009
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; METALLURGY; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS

A method of forming an anodizing film is provided to form a thin film having high corrosion resistance and various colors, increase operation efficiency by greatly reducing working hours, and obtain a film with high surface hardness and excellent heat resistance and antibacterial property. A method of forming an anodizing film comprises: a degreasing process of removing oil and fat adhered to the surface of a workpiece; an etching process of roughing the surface of the workpiece while dissolving the surface of the workpiece; a neutralization process of dipping the workpiece into an aqueous solution for 50 to 60 seconds to remove foreign metal matters generated in the etching process, the aqueous solution comprising 40 to 50 wt.% of sulfuric acid, 1.5 to 3 wt.% of nitric acid, 1.5 to 20 wt.% of hydrogen peroxide, and 27 to 57 wt.% of water; a film forming process of dipping the workpiece into an electrolytic solution with a temperature of 20 to 25 deg.C, and connecting an anode to the workpiece and applying 11.5 to 13.5 V of a DC voltage to the anode for 2 to 5 minutes to form an anodizing film on the surface of the workpiece, the electrolytic solution comprising 19 to 21 wt.% of water, 20 to 32.5 wt.% of sulfuric acid, 22.5 to 30.5 wt.% of nickel for fluorination, 2.35 to 4.35 wt.% of chromium, 10.5 to 16.5 wt.% of lactic acid, and 5.5 to 15.5 wt.% of nitric acid; and a sealing process of dipping a anodizing film-formed workpiece into a sealing solution with a pH of 4 to 6 to form a porous film on the surface of the anodizing film.