Aluminum is a relatively active metal, therefore, in the air will spontaneously form a very thin oxide film, in the atmosphere, high corrosion resistance. Because the thickness of the oxide film is relatively thin, the thickness is only about 4 nanometers, and the oxide film has loose structure, porosity, low hardness, poor wear resistance and low mechanical strength. Therefore, in order to achieve the purpose of protection, it is necessary to passivate the aluminum parts and generate a passivating film on the surface to improve the corrosion resistance of the aluminum alloy.
What are the advantages and applications of aluminum and aluminum alloys?
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Aluminum has the advantages of low density, high strength, good corrosion resistance, high electrical and thermal conductivity, weldability, good plasticity, easy processing, and excellent surface decoration performance.
In industrial production, pure aluminum generally adds some alloying elements to make various aluminum alloys, such as duralumin, superduralumin, rust-proof aluminum, cast aluminum and so on. The physical and mechanical properties of aluminum alloy are better than that of pure aluminum, so it is widely used in aircraft, automobiles, trains, ships and other manufacturing industries.
Under normal circumstances, passivation treatment is to use the chemical action of passivation agents to form a dense oxide film (passivation film) on the metal surface to enhance the corrosion resistance of the metal.
Passivating agent for aluminum
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Aluminum passivation agent is specially designed for aluminum and aluminum alloy passivation treatment. The passivation film produced after aluminum alloy treatment has good stability and corrosion resistance, which greatly improves the corrosion resistance of aluminum alloy materials. In the naked film neutral salt spray experiment, the time is longer. The film has a strong binding force with paint, and can be used as a good base for post-processing such as spray painting.
Passivation process of aluminum alloy
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Aluminum alloy passivation treatment can be applied to all aluminum and aluminum alloy surface oxidation corrosion resistance.
Through a large number of tests, it was found that after passivation, the oxidation resistance of aluminum and its alloy surface was increased by more than 5 to 10 times.
Aluminum alloy passivation treatment will not change the appearance of aluminum and aluminum alloy color, size, does not affect the post-treatment and performance.
Aluminum alloy passivation process, the operation is also very simple, everyone can master.
During the processing process, as long as the oil on the surface of the aluminum is cleaned, the residual liquid of the aluminum alloy oil remover is cleaned, directly impregnated in the aluminum passivation agent, let it stand for a few minutes, remove it, and wash it clean, the overall process of aluminum alloy passivation treatment is completed.
Aluminum can react with dilute hydrochloric acid, concentrated hydrochloric acid or dilute sulfuric acid to give off hydrogen
In cold concentrated sulfuric acid or concentrated nitric acid, the surface of aluminum will be passivated, but it can react with hot concentrated sulfuric acid and concentrated nitric acid
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Aluminum reacts more easily to strong alkali. Passivation treatment is to use the chemical action of passivation agent to form a dense oxide film (passivation film) on the metal surface to enhance the corrosion resistance of the metal.