What is Alodine?

Alodine is a chromate conversion coating that protects aluminum from corrosion. The process is very simple, requiring only 3 minutes of immersion to complete the process, with no equipment. The alodine process is currently one of the most suitable processes for the surface oxidation treatment of CNC aluminum parts.



Why does CNC aluminum parts need alodine?

Due to its low density, high strength and high electrical and thermal conductivity, good plasticity, easy CNC machined, and good corrosion resistance properties,aluminum materials are widely used in various industry fields.

Aluminum alloy is made of pure aluminum by adding some alloying elements.However aluminum alloy has better physical and mechanical properties than pure aluminum. Because aluminum element is a relatively active metal which can spontaneously form an extremely thin oxide film in the air, which makes it have better corrosion resistance, but the thickness for the film is very thin ,it is only about 4nm with low hardness and poor wear resistance. Therefore, it is necessary to manually cover the surface with a film to achieve the purpose of protection. It can usually be achieved through aluminum alodine solution immersion treatment technology.


Benefits for alodine?

(1)Aluminum alodine will not affect the thickness and mechanical dimension of the cnc machining parts,It will not change the surface roughness or color of the CNC machined products.

(2)The alodine cost is much cheaper than anodizing. Because the aluminum alloy alodine bath can be used repeatedly, with long life and low cost.

(3)Aluminum alloy alodine treatment can make the film more dense and the surface performance more stable.Compared with the traditional coating of anti-rust oil, the alodnie film formed has higher stability and stronger corrosion resistance.


Difference between alodine and anodize.

Alodine: according to the chemical reaction of aluminum alodine liquid, the lively aluminum metal surface layer becomes an inert surface layer, thus preventing the reaction between the external destructive substances and the metal surface to achieve the purpose of extending the rusting time of aluminum.

Anodizing: an electrolytic oxidation process in which the aluminum surface is usually transformed into an oxide film, which has protective, decorative, and other functional properties.


Different alodine color projects