EDM has the advantages of high machining accuracy, high surface quality and wide machining range, especially in the mold cavity machining of complex, precise, thin-walled, narrow slit and high hard materials, which has more advantages than high-speed milling, so EDM will still be the main means of mold cavity machining.
Compared with copper, graphite electrode has many advantages, such as less consumption, fast discharge speed, light weight and small coefficient of thermal expansion. Graphite mold is used in centrifugal casting, so gradually replacing copper electrode becomes the mainstream of EDM electrode. In contrast, graphite electrode materials have fast speed, graphite discharge is 2-3 times faster than copper, and the material is not easy to deform. It has obvious advantages in the processing of thin rib electrode. The softening point of copper is about 1000 degrees, which is easy to deform due to heat. The sublimation temperature of graphite is about 3650 degrees.
1. Light weight: the specific gravity is 1 / 5 of copper, suitable for making large-scale electrode
2. Good machining performance: cutting resistance is 1 / 3 of copper
3. Easy surface treatment: no burr after machining, easy to handle by hand
4. High temperature resistance: Sublimation gasification when the temperature reaches 3650 ℃, able to withstand greater current
5. Low coefficient of thermal expansion: 1 / 4 of copper, without deformation when heated
6. High speed of EDM: the EDM speed is 3-5 times faster than that of copper block, which is more obvious in large area or rough machining.
7. Low electrode loss: the ratio with copper is 2:4, which can be processed without damage.
1. CNC machining is more than three times faster than copper (high-speed machining machine), graphite can process 0.12mm, and can achieve 0.1mm sheet.
2. EDM is more than three times faster than copper in rough machining (faster for large electrode) and two times faster in finish machining. Reasonable use of graphite can reduce the comprehensive cost, improve the utilization rate of machine tools and increase the output of dies.
3. Good texturing effect (especially for high-end electronic products such as mobile phones, laptops, high-end car speaker mesh, etc.)
4. The processed medical devices are free of pollution