Anodic oxide film pre-hole-sealing method and hole sealing agent

Abstract

The invention discloses an anodic oxide film pre-hole-sealing method and hole sealing agent. The method comprises pre-sealing and spraying protection. The invention simultaneously discloses a scheme of the hole sealing agent for pre-hole-sealing of an anodic oxide film of an aluminum alloy workpiece, and the main components of a protective agent, wherein the hole sealing agent comprises the following components of 2-10 g / l of nickel salt, 0.5-10 g / l of fluoride, 0.1-0.5 g / l of a complexing agent, 0.1-0.5 g / l of a dust inhibitor, 0.001-0.1 g / l of a pH conditioning agent, 0.01-0.1 g / l of graphene oxide, 0.05-2 g / l of a surfactant, and pure water is taken as a solvent. Compared with the prior art, the method is simple, the corrosion resistance, alkali resistance, continuous acid-alkali resistance and car washing alkali resistance of the processed anodic oxide film of the aluminum alloy workpiece can pass tests, the high-temperature thermal cracking resistance is stable, and the antifouling capability is strong.

Description

technical field [0001] The invention relates to the field of anodic oxidation surface treatment of aluminum alloys, in particular to an alkali-resistant hole sealing process for aluminum alloy automotive exterior parts after anodic oxidation. Background technique [0002] Aluminum is the most abundant metallic element in the earth's crust, with a content above 7%. The density of pure aluminum is small (ρ=2.7g / cm 3 ), about 1 / 3 of iron, low melting point (660°C), aluminum is a face-centered cubic structure, so it has high plasticity (δ=32-40%, ψ=70-90%), easy to process, and can be Made into various profiles and plates. It has good corrosion resistance, but the strength of pure aluminum is very low, and the σb value in the annealed state is about 8kgf / mm2, so it is not suitable for structural materials. The alloy formed by adding certain elements can have high strength while maintaining the advantages of pure aluminum such as light weight, and the σb value can reach 24-60k...

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Problems solved by technology

[0003] Aluminum alloys are currently used in automobiles, such as automotive exterior parts, interior parts, hoods, doors, wheels, cylinders, cylinder heads, radiators, etc.; Ordinary anodic oxidation is used for decorative parts; however, the sealing or protection process of ordinary anodic oxide films cannot meet people's growing performance requirements, especially the guarantee of alkali resistance. At the same time, the existing processes are either complex , or the energy consumption is too large, or the metal texture is lost

[0004] Chinese invention patent CN201610455329.6 The sealing process steps are complicated, the energy consumption is large, and it is difficult to ensure the stability of alkali resistance

[0005] Chinese invention CN201610455329.6, although the sealing is improved into a two-step method, the alkali resistance performance is stably improved, but it cannot stably pass the continuous pH=1+pH=13.5 acid-base test

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