Method and apparatus for rapid preparation of anodic oxidation film on aluminium alloy products

Abstract

A method and equipment for quickly preparing an anodized film on an aluminum alloy product, characterized in that: the aluminum alloy product is suspended on the upper part of the casing, the aluminum alloy product is used as the anode, and 15-30% sulfuric acid is used as the electrolyte, The electrolyte is sprayed from multiple nozzles on the pipelines on both sides of the anode, and is continuously sprayed onto the anode after passing through the auxiliary cathode to form an anodized film; the voltage between the anode and the auxiliary cathode is 20-30V, and the anode The upper current density is 3-5A / dm2, and the electrolyte temperature is 20-30°C. Compared with the prior art, the present invention has the following outstanding advantages: 1) the anodic oxide film forming speed is 1.0-2.2 μm per minute; 2) the anodic oxide film thickness is 1-4 μm, and its corrosion resistance is better than that of chemical oxide film; 3) The anodic oxidation current density is 3-5A / dm2, which is increased by 3-5 times, which can meet the production requirements for the rapid formation of anodic oxidation film before coating of aluminum alloy products.

Description

technical field [0001] The invention relates to a method and equipment for anodic oxidation treatment of aluminum or aluminum alloy products before coating, in particular to a method and equipment for rapidly preparing anodic oxidation films on aluminum alloy products. Background technique [0002] In order to improve the corrosion resistance of aluminum alloy products, an oxidation treatment must be carried out before coating the aluminum alloy products to form an oxide film on the aluminum alloy products. At first, people used chromate chemical oxidation method to obtain an oxide film on aluminum alloy products, the film thickness was less than 4 μm, the texture was soft and not wear-resistant; then someone added chemical reagents such as chromic acid and potassium dichromate to the treatment solution. , Obtain an oxide film by spraying method to increase its film thickness. The disadvantage of the above solution is that the hexavalent chromium in the chromate is toxic, w...

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Problems solved by technology

However, the automotive industry and the construction industry, which require relatively high corrosion resistance and adhesion of the coating, cannot be popularized and applied.

In the 1980s, the titanium phosphate-zirconium phosphate solution was used to form the oxide film, and the performance was improved, but it still could not fully meet the use requirements. By the mid-1990s, the European aluminum can industry had adopted 100% chrome-free conversion film, but in the construction of aluminum The application of aluminum materials is still less than 25%; in order to solve the problem of oxidation treatment of aluminum materials in the construction industry and the aluminum industry in the automotive industry, organic components, such as silane and cerate, are added to the chromium-free chemical conversion solution. A new chromium-free treatment process is under development, but so far this treatment process does not meet the requirements of anodic oxidation film preparation before coating aluminum in the construction industry and the automotive industry

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