EDM is a new processing technology in machinery manufacturing industry, EDM of many high hardness metal processing, and processing of complex shape, high precision parts, can be used as a tool for the anode copper material, also can use graphite materials. Graphite material used as a tool electrode for electrical discharge machining must have the following conditions:
(1) the structure is compact and uniform, and there should not be coarse particles and large pores;
(2) has high mechanical strength, and good processing performance, can produce acute, flake shape or complex;
(3) the graphite electrode, which has a certain loss in the process of EDM, which should be as low as possible;
(4) the discharge characteristics are stable and the processing speed is fast. So the graphite is usually used in the process of electric discharge machining, and the structure of graphite with fine grain structure or extra fine grain structure is used. So the current Chinese electric spark machining graphite materials used in the market is more isotropic graphite structure.
In 2005, the domestic demand for electrical discharge machining of graphite is estimated to be 4000T, which uses high-grade graphite about 25%, using middle and low grade graphite accounting for about 75%. In the future may be increased by 10% in the year increased by. The use of imported high-grade graphite (mainly isotropic static pressure molding of isotropic graphite) about 10% of the total amount. There are many varieties of isotropic graphite used in EDM, which can be used in rough machining, semi finish machining, precision machining, ultra precision machining and precision machining