Coppergraphite

Coppergraphite, or copper-graphite composite, is a copper-based material in which graphite is dispersed within a copper matrix. The graphite serves as a solid lubricant, providing self-lubrication, reducing wear, and lowering the coefficient of friction at contacting surfaces, while copper provides high thermal and electrical conductivity.

Production methods vary but are commonly based on powder metallurgy. Copper and graphite powders are blended, compacted, and sintered to form a solid part. Alternative methods include infiltrating a graphite-containing copper melt or producing dispersion-strengthened copper with graphite particulates. Graphite content varies widely, typically from about 5 to 40 percent by weight or more, depending on the desired balance of friction, wear resistance, and mechanical strength.

Properties include the retention of much of copper’s thermal and electrical conductivity, although overall conductivity decreases as graphite content increases. The graphite provides solid lubrication, improving wear resistance and reducing the risk of galling in sliding or lightly loaded contact applications. The material generally offers good high-temperature performance, but excessive graphite can reduce mechanical strength and structural integrity. It is typically machinable using standard metalworking techniques.

Applications are broad in electrical and tribological contexts. Coppergraphite is widely used for electrical brush and contact materials, slip rings, bearings, cam tracks, and other sliding components where high current or heat generation occurs and self-lubrication is advantageous. It is particularly valued in electrical motors, generators, and switching gear.