Kesu Hardware specialize in one-stop manufacturing service for CNC machining and post finishes. We provide different kinds of anodizing services. Such as black anodizing, clear anodizing, and hard coating anodizing aetc. Anodizing color can be applied to requested Pantone number.

Anodizing/ Type II Anodizing

Usually, anodizing refers to the aluminium anodizing or aluminium alloy anodizing.

Aluminium anodizing is an process, during which the aluminium products or aluminium alloys products are used as anodes, which will be placed in an electrolyte solution for electrification, and the aluminium oxide film will be formed on the surface of products due to the electrolysis. 

After anodic oxidation treatment, the oxide film which generated on aluminum surface could be several micrometers to hundreds of micrometers. If anodizing is not specified, it usually refers to sulfuric acid anodizing.

Red Anodizing

Under normal circumstances, the film thickness of aluminum alloy anodizing (Type II Anodizing) is 5-8μm.

Ordinary aluminum anodizing (Type II Anodizing) is not suitable for cast aluminum. Because the anodizing effect of cast aluminum is not good, the surface is not shiny, and the color can be black only.

Principle

Black Anodizing

The principle of aluminum anodizing is essentially the principle of water electrolysis.

When the current passes, the following reactions will occur:

On the cathode, H2 is released according to the following reaction: 

2H + + 2e → H2

On the anode, 

4OH-4e → 2H2O + O2

The precipitated oxygen is not only molecular oxygen (O2), but also atomic oxygen (O), and ionic oxygen (O-2). Usually, they are represented by molecular oxygen in the reaction.

The aluminum which is used as the anode will be oxidized by the oxygen which precipitated from it, and forming an anhydrous Al2O3 film: 

2Al + 3[O] = Al2O3 + 1675.7KJ. 

It should be pointed out that not all of the oxygen generated interacts with aluminum, and part of it is  precipitate out in gaseous form.

Cathodic Reaction

H2：2H + + 2e → H2

Anode Reaction

4OH - 4e → 2H2O + O2

Al2O3 coat：

2Al + 3[O] = Al2O3 + 1675.7KJ

Available Types: Black Anodizing, Bead Blast Black Anodizing, Bead Blast Bright Black Anodizing. B.Blast Bright Black Anodizing. Black Anodizing (No Sand blasted). Clear Anodizing. 

Clear Anodizing

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