Why does aluminum sheet need to be anodized finish?
Anodized treatment can make the gloss of the metal surface remain unchanged for a long time, improve the corrosion resistance and mechanical strength, and obtain a decorative appearance after dyeing.
Anodized finish aluminum sheet is used in many places. Here are a few examples.
- Prevent product corrosion: The film layer obtained by the oxidation of the positive electrode has been properly sealed and has good stability in the atmosphere. No matter it is the oxide film obtained from sulfuric acid solution, oxalic acid solution or chromic acid solution in the normal process, its corrosion resistance is very good, such as daily aluminum pots, pots, washing machine linings, eccetera. The chromic acid oxidation method is particularly suitable for aluminum welded parts and riveted parts.
- Protection and decoration: On the oxide film with high transparency, the oxide film has the characteristics of being able to absorb a variety of agricultural production system dyes or inorganic pigments, and various bright and bright colors and patterns can be obtained on the oxide film. In addition, in recent years Many new processes have appeared, such as one-time oxidation and multiple coloring, firework patterns, wood grain patterns, oxidized offset printing transfer printing, porcelain oxidation, etc., which make the appearance of aluminum more beautiful and pleasing. This color film is both a decorative layer and a protective layer. Corrosion layer, such as lighters, gold pens and handicrafts.
- As a hard wear-resistant layer: in sulfuric acid or oxalic acid solution, a thick and hard film can be obtained by adjusting the process conditions of cation and oxidation, and the pores and absorption properties of the film can be used to store the selected oil , It is effectively applied to the working conditions under friction, and has the characteristics of lubrication and wear resistance, such as the engine cylinders and pistons of automobiles and tractors.
- As an electrical insulating layer: the oxide film layer of aluminum and its alloys has the characteristic of high resistance, and the thickness of the film layer is proportional to the resistance. This feature has certain practical significance as electrical insulation and can be used as a capacitor For the dielectric, aluminum oxide skin can also be used as the outer sheath of the cable, and its surface is used as an insulating layer to replace the rubber sheath and plastic sheath. When the film thickness is 27.5μm, the through voltage is 441V. If phenolic resin is used to fill the membrane holes, the breakdown voltage can be increased by 2 times. In oxalic acid solution, when the thickness of the membrane increases, an excellent insulating layer with a resistance of 200Ω and a breakdown voltage of 980V can be obtained. Of course, this feature can be used. In addition to being used for wires, it can also be used for other electrical appliances.
- As the bottom layer of spray paint and electroplating: due to the porousness and good adsorption capacity of the oxide film layer, it has good binding force with the paint film and the film of agricultural production system, and can be used as the bottom layer of paint. The film layer with relatively oxidized phosphoric acid can be used as the bottom layer of electroplating on aluminum.
- Used in modern buildings: Due to the introduction of electrolytic coloring of aluminum alloys, domestic electrolytic coloring has been increasingly used in architectural aluminum profiles in recent years. It not only has bronze, nero, rosso, eccetera. suitable for architectural colors, but also has excellent wear resistance. In general conventional oxidation, it is particularly worth mentioning that the light fastness is very good, and the color will not fade in the atmosphere under the sun and night exposure for more than 20 anni, which is incomparable with the oxidation coloring method. The aluminum profile oxidized by electrolytic coloring can not only be used for building doors and windows, but it is also particularly suitable for store counters and shelves.