It is well known that aluminum and its alloys will be oxidized in the air. The oxide film naturally formed on the aluminum surface is amorphous, which will make the aluminum surface lose its original luster. Although this natural oxide film will slightly passivate the aluminum surface, it is very thin, about 4 ~ 5 nm, with large porosity and poor mechanical properties, which cannot effectively prevent the aluminum metal from further corrosion by various media in the atmosphere. After anodic oxidation treatment, a dense film layer (from tens of microns to hundreds of microns) can be obtained on the surface of aluminum and its alloys, which is much thicker than that of natural oxidation. After sealing this artificial oxide film, the amorphous oxide film is transformed into a crystalline oxide film, and the pores are also sealed, so that the luster of the metal surface can remain unchanged for a long time, the corrosion resistance and mechanical strength are improved, and a decorative appearance can be obtained after dyeing. Because aluminum and its alloy products have many characteristics after anodic oxidation, aluminum anodic oxidation process is widely used in surface treatment of aluminum products.

Industrial applications can be roughly divided into the following categories. 

(1) Preventing corrosion of products: The film obtained by anodic oxidation has good stability in the atmosphere after proper sealing treatment. No matter 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 liners and so on. Chromic acid oxidation method is especially suitable for aluminum welded parts and riveted parts.

 (2) protection and decoration: on the oxide film with high transparency, the oxide film can absorb various organic dyes or inorganic pigments, and various bright colors and patterns can be obtained on the oxide film. In addition, in recent years, many new technologies, such as one-time oxidation and multiple coloring, fireworks pattern, wood grain pattern, oxidation offset printing, porcelain oxidation, etc., have made the appearance of aluminum more beautiful and pleasing to the eye. This color film is both a decorative layer and an anti-corrosion layer, such as a lighter.

 (3) As a hard wear-resistant layer, a thick and hard film can be obtained by adjusting the process conditions of anodic oxidation in sulfuric acid or oxalic acid solution. The pores and absorption properties of the film are used to store the selected oil, which is effectively applied to the working conditions under friction, and has the characteristics of lubrication and wear resistance, such as engine cylinders and pistons of automobiles and tractors.

 (4) As electrical insulation layer: The oxide film of aluminum and its alloy has the characteristics of high resistance, and the thickness of the film is proportional to the resistance, which has certain practical significance as electrical insulation. It can be used as the dielectric of capacitors, and it can also be used as the outer sheath of cables. It is more popular abroad to use aluminum oxide skin as insulation layer to replace rubber sheath and plastic sheath. When the film thickness is 27.5 μ m, its breakdown voltage is 441V V.

Method for discriminating aluminum alloy material

Recently, it has been reported that the market of aluminum alloy doors and windows is growing, and now many buildings use aluminum alloy doors and windows, so it has become necessary knowledge for consumers to learn to distinguish the quality of aluminum alloy materials. How to judge the quality of aluminum alloy doors and windows, whether it is aluminum alloy indoor doors (including partition doors) or aluminum alloy windows, decoration owners must pay attention to the following points when purchasing such products: Front: Materials for aluminum alloy doors and windows generally include three aspects: aluminum profiles, glass and hardware. When purchasing products, owners often pay more attention to the thickness of aluminum profiles and glass, but the requirements for hardware are not very high, which is not comprehensive. In fact, the state has certain standards for aluminum alloy doors and windows. The thickness, strength and oxide film of aluminum profiles used for high-quality aluminum alloy doors and windows can generally meet the national standards, such as the requirements of relevant national regulations: the wall thickness of aluminum profiles for aluminum alloy doors and windows should be not less than 1.2mm, and the oxide film thickness should reach 10 microns. Tempered glass is better than ordinary glass. Considering the safety and durability of doors and windows, stainless steel hardware fittings (such as screws, hinges, handles, etc.) are better than aluminum fittings, while pulley is better to choose POM products, because such products have higher strength and wear resistance, and are smooth and not easy to break during use. 

You know, damage to doors and windows usually starts with door and window accessories! Second: With good materials for processing, the next step is the processing of doors and windows. Because the technical content of aluminum alloy doors and windows is not high, and the degree of mechanization is not high at present, most of them still rely on the manual operation of installation workers, which requires operators to have good product quality awareness. It is very important to strengthen the operator's proficiency and product awareness in the production process. High-quality aluminum alloy doors and windows, with fine processing, smooth tangent and consistent angle (the main frame material is usually 45 degrees or 90 degrees), should not have obvious gaps in the splicing process, with good sealing performance and smooth opening and closing. Inferior aluminum alloy doors and windows, especially aluminum alloy outdoor window products, will have sealing problems if they are processed unqualified, not only leaking air and rain, but also the glass will burst and fall off under the action of strong wind and large external force, thus causing property losses and even injuries to the owners.

Link-B2B is a professional supplier listing service platform which will provide high quality and trustworthy supplier list to international buyers. If you are looking for aluminum alloy suppliers, feel free to visit Link-B2B.com and send a request.