How Does Graphite Replace Copper as An Electrode?

In the 1960s, copper was widely used as an electrode material, and its utilization rate was about 90%, while graphite was only about 10%. In the 21st century, more and more users begin to choose graphite as electrode material. In Europe, more than 90% of the electrode material is graphite. Copper, once the main electrode material, has almost lost its edge over graphite. What caused this dramatic change? Of course, graphite electrodes have many advantages.

(1) Faster processing speed: In general, the machining speed of graphite electrode is 2 ~ 5 times faster than copper, but edM is 2 ~ 3 times faster than copper, and the material is not easy to be deformed. The softening point of copper is about 1000 degrees, and it is easy to deform when heated. The coefficient of thermal expansion of graphite is only 36/30.

(2) Light weight: the graphite density is only 1/5 of that of copper, which can effectively reduce the burden of machine tools during large electrode discharge processing and is more suitable for the application of large molds.

(3) Low discharge consumption, because spark oil also contains carbon atoms, in the process of discharge, high temperature makes the carbon atoms in spark oil decompose, and then forms a protective film on the surface of graphite electrode, to compensate for the loss of graphite electrode.

(4) No burr; After the copper electrode is processed, the burrs need to be removed by manual dressing, while the graphite is made from the graphite electrode factory and has no burrs, which saves a lot of costs and makes it easier to realize automatic production

(5) Graphite is easier to grind and polish; Since graphite has only a fifth of the cutting resistance of copper, it is easier to grind and polish by hand

(6) Lower material cost and more stable price; As copper prices have risen in recent years, the price of isotropic graphite is lower than copper prices. Under the same output, the price of general graphite products is 30% ~ 60% lower than that of copper, the price is relatively stable, the short-term price fluctuation is very small.

Because of this incomparable advantage, graphite has gradually replaced copper as the preferred material for EDM electrodes.

The information is provided by EAF graphite electrode manufacturer.