Aluminum in the mechanical process of the surface problems encountered, after the film will be oxidized, will always be affected by some impurities.

To solve these problems is a headache for many enterprises, aluminum surface solution measures will be mentioned below. Of course, enterprises can develop better film forming technology to fight against oxidation if they have conditions.

An extremely thin oxide film is formed on the surface of aluminum in the atmosphere, which makes it have a certain anti-corrosion ability. However, due to the film is loose, porous and uneven, so it cannot be used as a reliable protective film, and the film is amorphous, which makes aluminum and taijin lose the luster of butyl and can not be used as a satisfactory decorative film.

Aluminum oxide film obtained by chemical oxidation, thickness -- generally o.3 -- 4P ", soft, wear resistance and corrosion resistance are low inch: anodic oxide film, so, except for special purposes, rarely used alone. It has a good adsorption capacity, the surface of the slowly xu paint, uT effectively improve the corrosion resistance of aluminum components and accessories c anodized after the treatment of oxidation film; The thickness is generally 5-20p ", and the thickness of the fecal anodic oxidation film can reach 60-25 concave p ".

First of all, the rate of film formation of aluminum is different from that of different types of aluminum. After electrochemical conversion treatment, the difference of external color is more obvious than that of oxide film obtained due to different process formulations. High purity of aluminum, slow film forming speed; Aluminum is less pure and vice versa. Therefore, the oxidation needs to be based on different aluminum to grasp the different. To achieve this, different models of aluminum products are not allowed to bind in the same string, so as not to be unable to control the appropriate oxidation time. Chemical treatment and mechanical treatment, or direct chemical treatment. For serious oxidation of the metal surface, the oxide layer is thicker, aluminum can not be directly with the solvent cleaning and chemical treatment, and it is best to mechanical treatment.

Some methods can serve as a reference: 1. Degrease treatment, with absorbent cotton wet solvent to wipe, remove oil, and then clean cotton cloth to wipe a few times. Common solvents include trichloroethylene, ethyl acetate, acetone, butanone and gasoline, etc. 2. Skim the following solution after chemical treatment: 3-3.5 ammonium hydrogen fluoride, 20-26 chrome oxide, sodium phosphate 2-2.5, 50 to 60 of sulfuric acid, boric acid, 0.4 to 0.6, 1000 in 25 to 40 ° C water dipping 4.5-6 min, namely for washing and drying. This method has high adhesive strength and can be used for epoxy and epoxy - butyronitrile adhesives within 4h after treatment. 3. In the following after degreasing solution for anodized: 22 g/l in sulfuric acid under the dc intensity of 1-1.5 A/dm2 impregnated 10-15 min, again in saturated potassium dichromate solution, in 95-100 ° C under dipping 5 to 20 min, and then washed, dry. The treated metal surface is highly reactive and prone to re-contamination by dust, moisture, etc. So the surface of the treated metal should be glued as soon as possible.

Aluminum oxide film also has the following characteristics:

(1) high penetration. The hardness of pure aluminum oxide film is higher than that of aluminum composite film, which is usually related to the composition of aluminum and the condition of electrolyte during anodic oxidation of industrial aluminum. The hardness of the ordinary oxidation film is 300Hv, and the hardness uI of the hard-turn oxidation film is 500Hv. The anodic oxidation film is not only of high hardness, but also of good wear resistance. In particular, the surface layer of ZL oxide film has the ability to adsorb lubricant, but also Mf further improve the wear resistance of the surface.

(2) high corrosion resistance. This is due to the anodic oxide film has a higher chemical stability. The anodic oxidation film of pure aluminum has better corrosion resistance than the anodic oxidation film of aluminum alloy. This is because the inclusion of aluminum alloy or forming metal compounds cannot be oxidized or dissolved, so that the oxidation film has a continuous or stoppage gap, and the corrosion resistance of the oxidation film is artificially reduced. Therefore, the membrane obtained after anodic oxidation must be sealed.

(3) good adsorption capacity. The anodic oxidation film of aluminum and aluminum alloy is a porous structure with a strong adsorption capacity, so the pore filled with pigments, lubricants and resins can further improve the anti-expansion, insulation, wear-resisting and decorative properties of aluminum:

(4) good insulation performance. The anodic oxidation film of aluminum no longer has the conductivity of metal, but becomes a good insulating material. The insulation breakdown voltage is greater than 3017/Pm:

(5) strong adiabatic heat resistance. This is because the thermal conductivity of anodized film is much lower than that of pure aluminum.

(6) strong adhesion of organic coating and electroplating coating.

(7) good functionality. By utilizing the porosity of the anodic oxidation film, functional particles can be deposited in the particles, and various functional materials c can be obtained. The functional components under development have electromagnetic function, catalytic function and separation function, etc. To sum up, after anodizing industrial aluminum, the oxide film formed on its surface has good characteristics of protection and decoration. Therefore, it is widely used in air traffic, electrical, electronic, mechanical manufacturing and light industry, as well as architectural decoration.

After the aluminum surface film is polluted, the subsequent coating quality will be affected. If the above method is not adopted, the new aluminum surface can also be self-assembled into a film. Through this latest film forming technology, the oxidation resistance is more advanced than the previous traditional technology.