Many advantages of graphite:
(1) Faster processing speed: Usually, graphite can be machined faster than copper $number times; and the discharge processing speed than copper fast $number times material is more difficult to deform: The thin rib electrode processing advantage is obvious; the softening point of copper is about 1000 degrees, it is easy to deform by heating, the sublimation temperature of graphite is 3,650 degrees, and the thermal expansion coefficient is only 1/30 of copper.
(2) Lighter weight: graphite density only 1/5 of copper, large electrode discharge processing, can effectively reduce the burden of machine tool (EDM), more suitable for the application of large-scale molds.
(3) The discharge consumption is smaller; because the spark oil also contains C atoms, in the discharge processing, high temperature caused the spark oil in the C atom is decomposed, in turn on the graphite electrode surface to form protective film, compensating the loss of graphite electrode.
(4) No Burr; After finishing, the copper electrode needs to be manually trimmed to remove burrs, while graphite processing has no burr, saving a lot of cost and making it easier to automate production.
(5) Graphite is more easy to grind and polishing, because graphite cutting resistance only 1/5 of copper, more easily manual grinding and polishing.
(6) The material cost is lower, the price is more stable; because of the rise in copper prices in recent years, the price of isotropic graphite is lower than that of copper, and the price of the universal graphite products of Toyo is lower than that of copper $number, and the price is more stable and short-term price fluctuation is very small.
It is this unparalleled advantage that graphite gradually replaces copper as the preferred material for EDM electrodes.
