Surface treatment method for improving corrosion resistance of aluminum alloy

Abstract

The invention discloses a surface treatment method for improving corrosion resistance of an aluminum alloy. Firstly, sand blasting treatment is carried out on the surface of the aluminum alloy, foreign matter and non-compact oxide skin adhering to the surface of the aluminum alloy are removed, and the fresh surface of the aluminum alloy is exposed; and then, a plasma spraying method is adopted forcarrying out high-temperature plasma surface oxygen-rich ion treatment on the surface of the aluminum alloy, that is, O2 is added on the basis of adopting Ar and H2 as plasma gas in traditional plasma spraying, O2 is ionized under high temperature and reacts with the aluminum alloy, a compact corrosion-resistant Al2O3 film is formed on the surface of the aluminum alloy, and therefore the corrosion resistance of the aluminum alloy is improved. Compared with the traditional aluminum alloy corrosion protection technology, the surface treatment method has the advantages of being efficient, low incost, free of waste water and waste gas pollution and the like.

Description

technical field [0001] The present invention relates to a kind of aluminum alloy surface treatment method, especially in order to make the aluminum alloy surface obtain compact Al 2 o 3 A surface treatment method for improving the corrosion resistance of aluminum alloy by oxide film. Background technique [0002] The content of aluminum in the earth's crust is only behind oxygen and silicon, accounting for more than 8% of the earth's crust. It is the most used, most produced, and most widely used metal material among non-ferrous metals. my country is a big producer and consumer of aluminum. Aluminum has been widely used in aerospace, transportation, light industrial building materials and other fields because of its advantages such as small specific gravity, good thermal conductivity, easy processing, and low price. However, the unstable three-electron structure of the outer layer of aluminum makes it exhibit active metallicity in corrosive media. Although aluminum can f...

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Problems solved by technology

(1) Chemical oxidation method: at a certain temperature, the metal aluminum and the oxidation solution undergo a chemical reaction to form a passivated insoluble oxide film on the surface of the aluminum alloy, such as chromate treatment and phosphochromate treatment, but The harmful effects of hexavalent chromium on the environment exist in this technology, and it is difficult to meet the requirements of environmental protection

(2) Anodizing method: Anodizing is a "universal" surface treatment of aluminum. It is a process in which aluminum or aluminum alloy is used as an anode in the electrolysis process to form an oxide film on its surface. The aluminum surface is formed after anodic oxidation Porous anodized film, the oxide film can be colored, in order to meet the requirements of corrosion resistance, the porous film is usually sealed to obtain different functions and decorations, but this method consumes a lot of power and costs high

(3) Organic matter coating treatment: coating techniques include brushing, dipping, spraying and electrophoresis, but this method is prone to marine microbial adhesion in the marine environment, increasing the friction between the hull and seawater

(4) Electroplating or chemical plating: Electroplating or chemical plating can obtain a beautiful metal appearance, but this method cannot obtain large-scale workpiece protection

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