Copper–tungsten (tungsten–copper, CuW, or WCu) is a mixture of copper and tungsten. As copper and tungsten are not mutually soluble, the material is composed of distinct particles of one metal dispersed in a matrix of the other one. The microstructure is therefore rather a metal matrix composite instead of a true alloy. The material combines the properties of both metals, resulting in a material that is heat-resistant, ablation-resistant, highly thermally and electrically conductive, and easy to machine. Copper tungsten (CuW, WCu) has been recognized as a highly conductive and ablation resistant composite material which is extensively used as copper tungsten or tungsten copper rods contacts in high voltage applications, tungsten copper heat sinks and electronic packaging material in thermal applications, and electrode in resistance welding and EDM applications.