Chromium-free passivation treatment process for aluminum alloy surface

An aluminum alloy surface, chromium-free passivation technology, applied in the field of aluminum alloys, can solve the problems of human body and natural environment hazards, hexavalent chromium compounds are highly toxic, and achieve excellent resistance to salt spray corrosion and increased surface contact angle. , the effect of accelerating the dissolution

Inactive Publication Date: 2020-11-06
合肥卓汇新材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The passivation film obtained by this treatment has good corrosion resistance and strong binding force with the organic coating, but the hexavalent chromium compound is highly toxic and has great harm to the human body and the natural environment. Countries around the world have formulated various strict measures limit its application

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0063] A chromium-free passivation treatment process for the surface of an aluminum alloy, comprising:

[0064] (1) Grinding:

[0065] The surface of the aluminum alloy workpiece is polished, and the silicon carbide sandpaper of 600#, 800#, and 1200# is used in turn to polish with water, and then polished on an automatic polishing machine, then cleaned, and dried to constant weight; when polishing, the particle size is used 1μm water-soluble diamond polishing paste for auxiliary polishing. The cleaning is to clean with acetone and distilled water respectively for 20 min in an ultrasonic cleaner.

[0066] (2) Tannic acid solution treatment:

[0067] Add the tannic acid solution into the vacuum reaction kettle, and then immerse the above-mentioned polished aluminum alloy workpiece in the tannic acid solution, then seal it, vacuumize it, adjust the temperature in the reaction kettle to 80°C, react for 40min, and then Take it out, wash it with clean water until it is neutral, a...

Embodiment 2

[0073] A chromium-free passivation treatment process for the surface of an aluminum alloy, comprising:

[0074] (1) Grinding:

[0075] The surface of the aluminum alloy workpiece is polished, and the silicon carbide sandpaper of 600#, 800#, and 1200# is used in turn to polish with water, and then polished on an automatic polishing machine, then cleaned, and dried to constant weight; when polishing, the particle size is used 1μm water-soluble diamond polishing paste for auxiliary polishing. The cleaning is to clean with acetone and distilled water respectively for 25 min in an ultrasonic cleaner.

[0076] (2) Tannic acid solution treatment:

[0077] Add the tannic acid solution into the vacuum reaction kettle, and then immerse the above-mentioned polished aluminum alloy workpiece in the tannic acid solution, then seal it, vacuumize it, adjust the temperature in the reaction kettle to 90°C, react for 50min, and then Take it out, wash it with clean water until it is neutral, a...

Embodiment 3

[0083] A chromium-free passivation treatment process for the surface of an aluminum alloy, comprising:

[0084] (1) Grinding:

[0085] The surface of the aluminum alloy workpiece is polished, and the silicon carbide sandpaper of 600#, 800#, and 1200# is used in turn to polish with water, and then polished on an automatic polishing machine, then cleaned, and dried to constant weight; when polishing, the particle size is used 1μm water-soluble diamond polishing paste for auxiliary polishing. The cleaning is to clean with acetone and distilled water respectively for 22 minutes in an ultrasonic cleaning machine.

[0086] (2) Tannic acid solution treatment:

[0087] Add the tannic acid solution into the vacuum reaction kettle, and then immerse the above-mentioned polished aluminum alloy workpiece in the tannic acid solution, then seal it, vacuumize it, adjust the temperature in the reaction kettle to 85°C, react for 45min, and then Take it out, wash it with clean water until it ...

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Abstract

The invention discloses a chromium-free passivation treatment process for an aluminum alloy surface and relates to the technical field of aluminum alloys. The chromium-free passivation treatment process for the aluminum alloy surface comprises the following steps: (1) grinding; (2) tannic acid solution treatment; (3) femtosecond laser processing; (4) passivation. According to the method, a uniformand compact passivation film is formed on the surface of the aluminum alloy through passivation, and after neutral salt fog treatment, the passivation film has excellent salt fog corrosion resistanceand can better protect the aluminum alloy; and the contact angle of the surface of the passivation film formed by the method is greatly increased, so that the hydrophobic property of the surface of the aluminum alloy after passivation treatment by the process is obviously improved.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloys, in particular to a chromium-free passivation treatment process on the surface of aluminum alloys. Background technique [0002] Aluminum alloy is widely used in aerospace, mechanical equipment, home appliances, construction and other fields because of its high specific strength, good thermal and electrical conductivity, beautiful color, non-magnetic, good plasticity, and no low-temperature brittleness. Its consumption is second only to steel, and it is the second most used metal material in the industrial field. However, the chemical properties of aluminum alloy are relatively active. In the atmospheric environment, an extremely thin oxide film (usually a few nanometers in thickness) is easily formed on the surface of the aluminum alloy, which has a certain protective effect on the substrate. However, the natural oxide film is too thin and easy to be damaged, and it is very easy to corro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C22/34C23C22/78
CPCC23C22/34C23C22/78
Inventor 郭平
Owner 合肥卓汇新材料科技有限公司
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