Cadmium is a sacrificial metallic coating electroplated onto a metal surface. Cadmium provides corrosion protection to the host metal by becoming a sacrificial layer which will corrode away before the substrate metal. Metal finishers may also provide a chromate conversion coating over the cadmium to enhance its corrosion protection or improve its appearance, as depicted in the picture.
The properties of cadmium make it attractive to a number of industries due to its ability to bond with a number of materials such as adhesives. The aircraft and aerospace industries have continually increased their use of cadmium electroplated components.
Cadmium also provides a superior conductive surface with low resistance to electrical current. Its wear resistance should also be considered an advantage with cadmium along with its resistance to other issues such as mold or bacteria.