Hard anodizing is a process that involves oxidizing the surface of metals, also known as thick film anodizing. After undergoing the hard anodizing process, aluminum alloys can form an oxide layer on their surface. If this process is applied to pure aluminum, a higher micro-hardness oxide layer can be achieved, and the same can be accomplished on aluminum alloys.

Hard Oxidation

Hard anodizing typically results in black anodized coatings with a natural finish, which is determined by the composition of the aluminum alloy material. For the same type of aluminum profile, different manufacturers can yield varying anodized coating colors. Even within the same aluminum alloy manufacturer, the material of the same type may have slight differences. Therefore, the natural finish of the anodized coating is generally used for internal product components.

Compared to regular oxidations, hard oxidation boasts strong adhesion; excellent insulating properties, and good wear resistance. It is non-toxic, and the oxidation film as well as the electrochemical process used to produce anodized films are harmless to humans. It has also garnered favor in the marketplace.