Electrode material selection of EDM equipment

EDM cavity commonly used electrode materials are mainly copper, graphite, special circumstances can also be used copper tungsten alloy and silver tungsten alloy material.
In order to improve the cavity mold processing accuracy, the electrode, the first is to find high corrosion resistance of electrode materials, such as copper, copper tungsten alloy, silver tungsten alloy and graphite electrodes. Due to the high content of copper tungsten alloy and silver tungsten alloy, high prices, machining more difficult, so the less commonly used for copper and graphite, the common feature of these two materials can be achieved in the large pulse roughing Low loss.
Copper electrodes are easy to make complex shapes and sheets with good dimensional accuracy. The use of copper electrodes, the processing stable, low surface roughness, finishing than the graphite electrode loss. But its machining performance is not as good as graphite.
Graphite electrode machining easy forming, light weight, large pulse current in the case of a smaller electrode loss. The disadvantage is easy to produce arc burn phenomenon, the electrode loss when finishing larger.
Even if the same workpiece processing, processing accuracy of different parts are not the same. Select the electrode material to ensure the accuracy of the premise, should be to significantly improve the processing efficiency for the purpose. High-precision parts of the processing of copper can be selected as the rough electrode material, the choice of copper tungsten alloy as the finishing material; high precision parts of the rough machining can be selected copper material; general processing available graphite as roughing material, finishing selection Copper material or graphite can also be; precision is not high, the rough finishing are selected graphite. Here's the optimization program is emphasized, take full advantage of the graphite electrode processing speed characteristics.