what is anodizing and What are the benefits of anodizing aluminum plates?

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  1. what is anodizing?

Anodic oxidation is a kind of oxidation mode of aluminum oxide plate, refers to the electrochemical oxidation of metal or alloy, aluminum and its alloy in the corresponding electrolyte and specific technological conditions, due to the action of external current, in the process of forming a layer of oxide film on aluminum products (anode).

Anodizing in aluminum oxide plate can not only solve the surface hardness, wear resistance and other defects, but also prolong the service life of aluminum and enhance the aesthetic degree, has become an indispensable part of aluminum surface treatment, is the most widely used and very successful process.

Metal materials are used more and more in various kinds of existing products. Metal materials can better reflect product quality and highlight brand value. Among many metal materials, aluminum is the first to be used by various manufacturers because of its easy processing, good visual effect and rich surface treatment means.

  1. Why is anodizing necessary?

Aluminum is a relatively active metal, but also easy to passivate metal, in the air surface is easy to generate natural oxide film, why should be anodized?

Because the natural oxide film generated in the air is only 0.01~0.1μm thick, decorative and protective is poor, and this layer of oxide film is non-crystalline, so that the surface of aluminum alloy lost the original luster, loose porous, uneven.

After the anodic oxidation treatment, can make the oxide film thickened to tens of microns, even hundreds of microns. And the surface is shiny, dense and uniform. Aluminum film has strong microporous adsorption capacity and can be colored into a variety of beautiful and gorgeous colors.

  1. The principle process of anodizing

In acidic solution, hydrogen is precipitated on the cathode when the current passes through. Oxygen (including molecular oxygen, atomic oxygen and ionic oxygen) is precipitated on the anode, which is represented by O2 in the reaction. Aluminum as the anode is oxidized by the oxygen precipitated on it to form alumina.

(Schematic diagram of anodizing aluminum alloy)

The oxide film formed by anodizing aluminum plate includes a dense film and a pore film. The thickness of the dense film layer (barrier layer) is very small, and the pore film layer has a large number of pores (up to hundreds of millions per square centimeter), so it can be colored to obtain a decorative appearance.

  1. Advantages after anodizing

1) Corrosion resistance: film thickness and sealing quality affect its performance.

2) Hardness and wear resistance: hard oxide film can improve the hardness and wear resistance.

3) Decorative: While maintaining the luster and texture of metal, it can be colored into colorful colors.

4) Electrical insulation: aluminum is a good conductor of electricity, and oxide film is a high resistance insulating film.

5) Transparency: the higher the purity of aluminum, the higher the transparency of oxide film.

6) Functionality: Using the porosity of oxide film, functional particles can be precipitated in micropores to obtain functional materials.

5, commonly used oxidizable aluminum alloy

Different trace elements have different effects on the anodizing effect. From the oxidation effect of each brand, pure aluminum oxidation effect is the best, 7 series due to the high content of zinc, zinc is the chemical component that has the greatest influence on the oxidation effect, so 7 series oxidation effect is poor. Generally speaking, the oxidation effect decreases in the following order: 1>5>6>3>2>7. Common aluminum plate alloys 1060, 5052, 6061, 6063 and so on

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