W-Cu 

 Tungsten is theoretically the best metal electrode material. Its strength, density and hardness are high, similar melting point 3500 ℃, so the EDM process, the actual loss is very small tungsten electrode. But for pure tungsten electrodes there are two difficulties: 1. Extremely difficult to process 2 is expensive so the use of the plasticity of copper, high conductivity, etc., made of composite materials, it becomes a treasure in the electrode - tungsten copper electrodes 
 Tungsten copper alloy conductive properties, softening temperature, high resistance to arc erosion, it is ideal for advanced welding materials, the basic consumption can be achieved without processing to reduce the frequency of correct electrode, greatly increasing productivity. Performance characteristics of the arc off a good electrical and thermal conductivity of small high-temperature thermal expansion