Graphite can replace copper as a discharge material

Update:29-09-2019
Summary:

(1) Faster processing speed: Under normal circumstances […]

(1) Faster processing speed: Under normal circumstances, the machining speed of graphite can be 2~5 times faster than that of copper; and the electric discharge machining speed is 2~3 times faster than copper; the material is less prone to deformation: processing at thin rib electrode The upper limit is obvious; the softening point of copper is about 1000 degrees, which is easy to be deformed by heat; the sublimation temperature of graphite is 3650 degrees; the thermal expansion coefficient is only 1/30 of that of copper.

(2) Lighter weight: The density of graphite is only 1/5 of that of copper. When large electrodes are subjected to electrical discharge machining, the burden on the machine tool (EDM) can be effectively reduced; it is more suitable for application on large molds.

(3) The discharge consumption is smaller; since the spark oil also contains C atoms, during the electric discharge machining, the high temperature causes the C atoms in the spark oil to be decomposed, and a protective film is formed on the surface of the graphite electrode to compensate the graphite electrode. loss.

(4) There is no burr; after the processing, the copper electrode needs to be manually trimmed to remove the burr, and the graphite is processed without burrs, which saves a lot of cost and is easier to realize automatic production;

(5) Graphite is easier to grind and polish; since graphite has a cutting resistance of only 1/5 of that of copper, it is easier to perform manual grinding and polishing;

(6) The material cost is lower and the price is more stable; due to the rising copper price in recent years, the price of isotropic graphite is lower than that of copper. Under the same volume, the price of the universal graphite product of Toyo Carbon is lower than the price of copper. % ~ 60%, and the price is more stable, short-term price fluctuations are very small.