Aluminum alloy surface treatment method

Abstract

The invention discloses an aluminum alloy surface treatment method which comprises the following steps: 1) adding 300g / L sodium hydroxide, 150g / L zinc oxide, 20 - 25g / L potassium sodium tartrate and 30g / L potassium pyrophosphate to distilled water to prepare a zinc plating solution; 2) adding 50g / L nickel sulfate, 20-25g / L sodium hypophosphite and 80g / L sodium citrate into the distilled water to prepare a nickel salt solution; 3) wiping an aluminum alloy surface with degreasing cotton wiped with an ethyl acetate solvent to removing surface grease; 4) etching the aluminum alloy after the degreasing treatment in a nitric acid solution for 9 seconds to remove an oxidation film on the aluminum alloy surface, then washing with water and drying; 5) immerging the etched aluminum alloy in the zinc plating solution, holding for at room temperature for 2 minutes, washing, then again immerging in a 35% concentrated sulfuric acid solution for 2 minutes, then washing with water and drying; 6) immerging the galvanized aluminum alloy in the nickel salt solution with the nickel salt solution temperature controlled at 95DEG C; and 7) drying. By the aluminum alloy surface treatment method, a coating with very good uniformity can be obtained, and the coating is high in hardness, high in brittleness, smooth, easy to braze and wear-resisting.

Description

technical field [0001] The invention relates to an aluminum alloy surface treatment method. Background technique [0002] There are many surface treatment methods for aluminum alloys, such as physical methods, chemical methods, physicochemical methods, and comprehensive methods. The commonly used method is anodic oxidation method, which forms a conversion film on the surface of aluminum alloy by electrochemical method. Although this method can improve the corrosion resistance of aluminum alloy, its ability to adapt to the environment is poor, and the conversion film layer is not uniform enough and easy to fall off. , the wear resistance has not been improved. Contents of the invention [0003] The object of the present invention is to provide a surface treatment method for aluminum alloy, which can obtain a coating with good uniformity, high hardness, high brittleness, smoothness, easy brazing and good wear resistance and corrosion performance. [0004] In order to achie...

AI Technical Summary

Problems solved by technology

The commonly used method is anodic oxidation method, which forms a conversion film on the surface of aluminum alloy by electrochemical method. Although this method can improve the corrosion resistance of aluminum alloy, its ability to adapt to the environment is poor, and the conversion film layer is not uniform enough and easy to fall off. , the wear resistance has not been improved