Electrical contacts are the contact elements in switching electrical appliances; such contact is called “electrical contact.” Their function is to connect or disconnect current. During operation, they open or close circuits due to relative motion, or maintain circuit continuity through rotation or sliding. Therefore, electrical contacts are the core nodes in the electrical transmission process, and their performance directly determines the stability of electrical transmission and electrical equipment. Ideal electrical contact materials need to possess good physical, mechanical, and chemical properties, as well as excellent processing, manufacturing, and electrical properties.
Electrical contact materials have a history of nearly a century. Initially, pure iron, pure gold, and pure platinum were used. From the 1940s onwards, pure metals or alloys such as Ag, Cu, AuAg, PtIr, and PdAg were adopted. To conserve precious metal materials, silver oxides, multi-component precious metals, and various precious metal composite materials were developed from the 1950s onwards. Since the 1970s, copper-chromium electrical contact materials have also seen significant development, mainly used in vacuum switching appliances.
