Aluminum is perhaps the metal that is most closely associated with the process of anodizing, although other nonferrous metals can also be finished using this method. It is an electrochemical process that transforms the surface the aluminum to produce a high level of corrosion resistance and to also provide a durable and aesthetically appealing surface.

The Process

It is important to realize that the choice of aluminum anodizing is very different than any applied coatings. This includes both surface coatings, such as paint, or with an electroplating process where the plating bonds with the surface of the aluminum.

The process of aluminum anodizing occurs in an acid bath that contains specific electrolytes. There is a cathode positioned in the interior of this bath or tank, and the aluminum part or component itself forms the anode.

An electric current is then passed through the electrolyte solution that causes the release of oxygen molecules in the solution. These are attracted to the aluminum on the surface of the part, resulting in what amounts to a controlled and precise oxidation process.

The Benefits

The obvious benefit to aluminum anodizing is that it is a process that is uniform across the surface of the aluminum part, piece or component in the electrolyte bath. This allows for complete treatment of the surface at the same time and rate regardless of the complexity of the shape.

This speeding up and control of the natural oxidation creates a surface that is of the aluminum base metal, so there is never any peeling of the surface. Additionally, this anodic layer is non-conductive, which is important for many applications.

Finally, the anodic layer produced through the anodizing process has better adhesion, creates a smoother surface that requires less lubrication and also allows for dyeing of the metal, an important considering for OEM components as well as decorative parts.