The Secrets of Anodic Oxidation

Anodising is the electrochemical oxidation of metals or alloys. The principle is to use the metal or alloy parts as anode, using electrolysis method to make its surface form oxide film.

Materials for Anodising

The commonly used material for anodic oxidation is aluminium. In addition to aluminium, the metals used for surface anodisation in the industry include magnesium alloys, copper and copper alloys, zinc and zinc alloys, steel, cadmium, tantalum, zirconium and so on.

Advantages：

1. Corrosion resistance.  Aluminium oxide film is very stable in air and soil, and has a strong bond with the substrate. Generally, after oxidation, it will be dyed and sealed or sprayed to further enhance its corrosion resistance.
2. High hardness and abrasion resistance. The hardness of the anodic oxide film is very high, its hardness is about 196-490HV, because the high hardness determines the very good abrasion resistance of the oxide film.
3. Decorative. Oxide film structure is porous honeycomb junction, the porous nature of the film so that has a good adsorption capacity, can be used as a coating layer of the substrate can also be coloured to improve the decorative effect of the metal.
4. Organic coating and plating adhesion.  Anodising changes the chemical properties and physical structure of the metal surface, forming a dense oxide film. The bonding force between this oxide film and the metal substrate determines the adhesion of anodising.
5. Electrical insulation. The anodic oxide film of aluminium has high impedance and low thermal conductivity, and its thermal stability can be as high as 1500 degrees Celsius, so it can be used as the dielectric layer of electrolytic capacitors or the insulating layer of electrical products.

Aluminum anodized color plates-------- The rainbow doesn't even have that many colors!