Anodizeing Surface Finishing For Aluminum Die Casting  Part

Anodizing is a surface treatment applicable in decorating and improving the functional properties of nonferrous materials such as aluminum, magnesium, and zinc. It is an electrochemical process, making the metal durable and corrosion/scratch-resistant. There are three types of aluminum anodizing, namely Type I, Type II, and Type III. Below is the general procedure for using it with aluminum:

• Cleaning: The aluminum die casting is cleaned to remove impurities that can affect the process’s quality.
• Placement: The cast part is placed into a bath containing an electrolytic solution. The electrolytic solution depends on the type of anodizing method you are using.
• Apply current: Direct current is passed through the bath, creating pores on the aluminum die casting. The negatively charged O2- forms aluminum oxide, acting as the die cast aluminum surface finish.

Anodizing is a simple yet cost-effective process. Hence, it is very popular in the automotive, food, and electrical industries. Depending on the electrolytic solution you use and the amount of current passed, there are different types of anodizing;

– Type 1 Anodizing

This anodizing uses chromic acid and can create the thinnest anodic oxide surface (at least 0.0001inches). Aluminum die casts subjected to this process are carrion resistant and slightly dyeable.

– Type 2 Anodizing

This process involves sulfuric acid, which is stronger and creates a thicker surface (about 0.0002 – 0.001). Aluminum die casting subjected to this anodizing becomes corrosion resistant and is highly dyeable.

– Type 3 or Hardcoat Anodizing

This also uses sulfuric acid but a higher electric current. Hence die casts subjected to this anodizing have thicker anodic oxide layers (>0.001), are corrosion and abrasion-resistant, and with the highest dyeing potential.