A Complete Guide for Aluminum Anodizing

Do you know what is the most commonly used surface finish for aluminum? It should be anodizing. This is one of the most commonly used post-processing methods for aluminum.

Anodized aluminum parts not only improve aesthetics, but also form a layer of oxide that enhances corrosion resistance. What is the process of anodizing? What are its advantages? Are there any limitations? You may not be familiar with anodizing yet, let us show the specific reasons for you!

What Is the Process of Anodizing?

Aluminum Anodizing

Anodizing is a process that goes through multiple electrochemical reactions, which include multiple steps. First, we need to put the aluminum part in sulfuric acid, which helps to clean its surface and remove its natural oxide layer in preparation for the next oxidation. In the second step, after several cleanings, it is put into an electrolytic solution (sulfuric acid or chromic acid).

After an electric current is applied, an electrochemical reaction occurs between the aluminum part and the solution, which fills the surface of the aluminum part with voids and creates a stronger layer of aluminum oxide. (In this process, we need to note that the oxidation time of different size parts is also different.) After that, we only need to put the cleaned aluminum parts into the sink we have tinted and it can be colored.

How Many Types of  Aluminum Anodizing Do We Have?

There are three types in total. The three are different, and you can choose one of them according to your project requirements.

If you are only using it for decorative aluminum parts, then we recommend that you use anodizing type one. Because this anodizing process is the most basic type of the three. It produces the thinnest oxide layer. Unlike the other two, the electrolytic solution it uses is chromic acid.

If you need a thicker oxide layer, anodizing type 2 and anodizing type 3 are better options. The two processes are very similar, the electrolytic solution used in both is sulfuric acid, but the thickness of the oxide layer produced by the two is different. The latter is thicker than the former to prevent corrosion and scratches.





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