Tungsten Copper Electrode and Graphite Electrode Comparison

EDM (Electrical Discharge Machining), which the properties of the using electrode material have a direct effect on the overall performance (such as the instrument consumption, the removal rate of material, the surface quality and so on). Therefore, in the process of EDM, the choice of the electrode materials is the key factor in the manufacturing process. Electrode materials not only need the good performance in thermal and electrical conductivity, but also need the low coefficient of thermal expansion and other mechanical properties requirements so that the excellent heat resistance, deformation resistance and low consumption can be ensured. With the popularization and developments of EDM technology, the related electrode materials have been reforming gradually. At present, already in production and are being developed in the electrode materials include graphite (C), tungsten (W), copper (Cu) and other elemental metal or nonmetallic substance, steel, cast iron, copper-based or tungsten-based alloy composite material, polymer composites, diamond, etc.

The graphite can be used in EDM with large discharge current, which has low consumption in roughing process and has high consumption in finishing process and it is difficult to meet the surface roughness required. In addition, the proportion of graphite electrodes is relatively light, brittle, difficult to use in general machining thin or fine hair processed into a shape, which in some fine or complex shapes EDM application has been subject to certain restrictions. By comparison, tungsten copper electrode material is a kind of new high-performance electrode material that has high strength, low coefficient of thermal expansion and excellent spark erosion resistance, which has been widely used in machining tool steel and tungsten carbide workpiece. However, as the price of tungsten copper electrode is relatively higher than ordinary graphite electrodes or copper electrode material prices, which is also the one of barrier to popularize tungsten copper electrode material.