Compared with copper, graphite material has the advantages of less consumption, fast discharge speed, light weight and small thermal expansion coefficient, so it gradually replaces copper electrodes and becomes the mainstream of EDM materials.
(1) Fast.
Graphite discharge is 2~3 times faster than copper discharge, the material is not easily deformed, and has obvious advantages in the processing of thin-ribbed electrodes. The softening point of copper is about 1000C, and it is easy to deform due to heat. The sublimation temperature of graphite is about 3650C. In contrast, the thermal expansion coefficient of graphite is only 1/30 of the thermal expansion coefficient of copper; the machining speed of graphite is fast, which is 3 to 5 times that of copper electrode machining, and the finishing speed is particularly prominent, and its strength is very high. High (50~90mm) ultra-thin (0.2~0.5mm) electrodes are not easily deformed during processing. And in many cases, the product needs to have a good texture effect, which requires that the overall common electrode should be made as much as possible when making the electrode, and there are various hidden corners when making the overall common electrode. Due to the easy trimming characteristics of graphite, it makes This difficulty is easily solved and greatly reduces the number of electrodes, which cannot be done with copper electrodes.
(2) light weight
The density of graphite is only 1/5 of that of copper, and it can effectively reduce the burden on the machine tool when large electrodes are used for electrical discharge machining, and is more suitable for the application of large molds.
(3) The loss is small.
Since the spark oil contains carbon atoms, the carbon atoms in the spark oil are decomposed at high temperature during EDM, and a protective film is formed on the surface of the graphite electrode to compensate for the loss of the graphite electrode.
(4) No burrs.
Copper electrodes need to be deburred manually after processing; graphite has no burrs after processing, which not only saves a lot of cost and manpower, but also makes it easier to realize automatic production
(5) Easy to polish.
Since the cutting resistance of graphite is only 1/5 of the cutting resistance of copper, it is easier to perform manual grinding and polishing in operation.
(6) Low cost.
Due to the continuous increase in the price of copper in recent years, the price of isotropic graphite is now lower than that of copper in all aspects; for carbon electrodes and graphite products under the same volume conditions, the price of graphite products is 30% to 60% lower than that of copper products , the price is relatively stable, and the short-term price fluctuation is relatively small.
Search Blog
