In Europe, more than 90% above use the graphite as electrode material. Copper electrode materials, the once dominant, compared with graphite electrode and its advantages almost disappeared. Because the spark oil also contains C atoms, in the discharge process, the high temperature leads to the C atoms in the spark oil is broken down, and in turn to form a protective film on the surface of the graphite electrode, the loss of the graphite electrode is compensated.
Cause of graphite electrode:
1.Faster processing speed. In general, the machining speed of graphite can be 5 – 2 times faster than copper, while the discharge rate is 3-5 times faster than that of copper.
2.Material is not easy to deform, and it has obvious advantage in the processing of thin rib material. The softening point of copper is about 1000 degrees, it is easy to deform due to heat, the sublimation temperature of graphite is 3650 degrees, and the coefficient of thermal expansion is only 1/30.
3.Lighter weight. The density of the graphite is only 1/5 of copper, and the large electrode can effectively reduce the burden of machine tool (EDM), and it is more suitable for the application of large scale mold.
4.Discharge consumption. Because the spark oil also contains C atoms in the discharge process, high temperature oil spark decomposition of C atom, and form a protective film on the surface of the graphite electrode, graphite electrode loss compensation.