Anodizing is a surface treatment technology based on electrochemical reactions, primarily used for corrosion protection, aesthetics, and improving surface properties of metals and alloys. The process typically involves placing a metal or alloy component as the anode in an electrolytic solution, where an applied electric current forms a thin oxide film on its surface. This oxide layer alters the surface condition and properties of the metal, enabling surface coloring, enhanced corrosion resistance, improved wear resistance, and increased hardness, among other benefits.

Anodizing is widely applied to metals and alloys such as aluminum, magnesium, and titanium. Taking aluminum anodizing as an example, aluminum or its alloys are placed in a corresponding electrolyte (e.g., sulfuric acid, chromic acid, or oxalic acid) as the anode, and electrolysis is performed under specific conditions with an applied current. After oxidation, the surface of the aluminum or its alloy forms an aluminum oxide film, typically 5–30 micrometers thick. Hard anodized films can reach 25–150 micrometers in thickness. After treatment, aluminum or its alloys exhibit higher hardness and wear resistance, up to 250–500 kilograms per square millimeter, along with excellent heat resistance, insulation, and corrosion resistance.

Anodized non-ferrous metals or their alloys are widely used in various fields, including mechanical parts, aircraft and automotive components, precision instruments, wireless devices, daily-use products, and architectural decorations. This technology not only enhances product performance but also enriches their visual appeal, contributing significantly to the development of modern industry and manufacturing.