Aluminum anodizing is a process whereby the corrosion resistance of aluminum metal is increased. In this process, a layer of oxide is created on the surface of the metal.
The Process
Through electrolytic means during this process, an oxide protective coating is produced
Many times this electrolytic process is performed on aluminum metal. The process is as follows:
To begin with, the aluminum metal part is placed into an electrolytic solution bath it contains a cathode. Next, the current is introduced into the solution. Subsequently, hydrogen is produced from the cathode which facilitates the formation of oxygen upon the anode’s surface. After this, a metal oxide film develops on the surface of the treated part.
The application of this aluminum anodizing process and how the process is carried out to determine the thickness of the oxide layer produced on the aluminum part. The thickness can reach a level of 100 times greater than the natural development that would occur on the aluminum part exposed to oxygen exclusively.
Greater corrosion resistance exists with anodized aluminum and aluminum alloy parts than those parts that are not treated. These parts thus treated are highly resistant to the wearing action that occurs when two parts rub together, in particular this is true with threaded components in a process called galling.
Anodized aluminum parts have operating life spans which are longer than parts that are non-anodized.
Anodized Aluminum
Better adhesion of paints and glues to surfaces is possible through the process of aluminum anodizing. Enhanced surface adhesion capability is made possible due to the pores that are present in the protective oxide layer.
It is very common for anodizing process to be applied to aluminum and aluminum alloys. However, metals such as titanium, zinc, and magnesium may also be protected by the process of anodizing.
Based on the electrolytic solution utilized in the process, there are different methods of anodizing that exist. For instance, the solution commonly used in the anodizing process has changed over time. At an earlier time, chromic acid was the solution used for the protection of parts and components in commercial facilities. Today sulfuric acid is a common electrolytic solution used in the anodizing process.
