Anodic oxidation and surface treatment method of aluminum alloy part and anodic oxidation treatment liquid thereof

Abstract

The invention discloses a surface treatment method of an aluminum alloy part containing zinc and magnesium elements. The surface treatment method comprises the following steps: the aluminum alloy part is provided; the aluminum alloy part is polished to reach a mirror surface effect; the aluminum alloy part is degreased by using degreasing solution; the black film stripping treatment is performed tothe aluminum alloy part; anodic oxidation treatment liquid, including acid solution and an additive with a concentration of 0.5 mg / L to 25 g / L, is used for anodically oxidizing the polished aluminum alloy part to form an oxide film on the surface of the aluminum alloy part, wherein the additive is one or several in ammonium adipate, 1, 2, 3-benzotriazole, oxalic acid, sodium malate or glycerin; and closing liquid is used for sealing the anodically oxidized aluminum alloy part. The invention further provides the anodic oxidation treatment liquid applied to the surface treatment method and an anodic oxidation treatment method. The aluminum alloy part, obtained by the surface treatment method, has no bank markon the surface, and has better glossiness.

Description

technical field [0001] The invention relates to a surface treatment method for an aluminum alloy part, in particular to an anodic oxidation method and a surface treatment method applied to an aluminum alloy part containing zinc and magnesium elements, and an anodic oxidation treatment solution used in the above method. Background technique [0002] Al-Mg-Zn series aluminum alloys have excellent characteristics such as light weight, low density, good heat dissipation, and strong pressure resistance, which fully meet the requirements of high integration, lightness, miniaturization, impact resistance, electromagnetic shielding and heat dissipation of electronic products. Requirements, more and more become the first choice for electronic product casing materials. [0003] However, when the Al-Mg-Zn series aluminum alloy is used as the material for the casing of electronic products, although the product has the required strength characteristics, its appearance is flat, which limi...

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Problems solved by technology

[0003] However, when the Al-Mg-Zn series aluminum alloy is used as the material for the housing of electronic products, although the product has the strength characteristics that meet the requirements, its appearance is flat, which limits its wide application.

At present, Al-Mg-Zn series aluminum alloys usually require the following processes as the surface of electronic product casings, such as sandblasting, wire drawing, baking paint, sand surface anode, etc., but the surface is rarely treated with high-gloss mirror anodization, mainly Because when the surface of the Al-Mg-Zn series aluminum alloy is mirror-finished, there will often be strips of material lines and corrosion spots. This is because Cu, Zn or MgZn in the Al-Mg-Zn series aluminum alloy will 2 Such intermetallic compounds are preferentially dissolved in the matrix Al, and small pits will be formed microscopically, and they will appear as strips of material grains macroscopically, resulting in low gloss on the surface of Al-Mg-Zn aluminum alloys, which seriously affects its Appearance

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