1. Lighter Than Copper Electrodes
The density of graphite is about one-fifth that of copper. Under the same volume, the weight of a graphite electrode will be lighter than that of a copper electrode, and when large electrodes are used for discharge processing, the graphite electrode can effectively reduce the burden on the EDM machine.
2. No Burrs After Use
Copper electrodes need to be manually deburred after processing, while graphite electrodes have no burrs after processing, which saves labor and makes automated production simpler.
3. Faster Discharge Speed
Graphite electrode discharge speed is about 2-3 times faster than copper electrode, and the material is not easy to deform, giving an obvious advantage in processing thin bar electrodes. Copper softens at about 1000 deg C and deforms due to heat, while graphite can withstand temperatures up to about 3650 deg C. The thermal expansion coefficient of graphite is about one-thirtieth that of copper.
4. Lower Cost Than Copper Electrodes
Because of the rising price of copper in recent years, the price of graphite is lower than copper under the same conditions; at the same volume, the price of a graphite electrode is 30 to 60 percent lower than that of a copper electrode, and the price is more stable with smaller short-term fluctuation.
5. Lower Electrode Wear
Because the carbon atoms in the spark oil are decomposed by the high temperature during discharge, a protective film forms on the graphite electrode surface, offsetting the loss of the graphite electrode, so the electrode wear rate is smaller.
6. Easier to Polish
Because the cutting resistance of graphite is about one-fifth that of copper, grinding and polishing are simpler.
Frequently Asked Questions
Why are graphite electrodes lighter? Graphite density is about one-fifth of copper, reducing the burden on EDM machines.
How much faster is graphite discharge? About 2-3 times faster than copper electrodes.
Why is graphite electrode wear lower? A protective film forms on the surface during discharge, offsetting electrode loss.
