Influence of Plasma Channel Change on the Surface Topology in the Electrical Discharge Machining

For the EDM, it is important that the surface topology can be determined for given process parameters in advance. Simulations with constant plasma channel radius are very inaccurate and only give a limit of thermally-influenced zone to. Many functional relationships of the temporal change of the plasma channel are only for small time periods and do not reflect properties of the dielectric. In the paper is shown how various properties of the dielectric contribute to the change of the plasma channel and the plasma channel as different behaviors can be treated with one simulation program. The maximum thermal load may be calculated by selective application of simulation, but also the topologies through moving or split plasma channels. This extended simulation is important because in the micro-EDM there are process instabilities leading to the splitting of the plasma channels. The simulations are reviewed on the basis of individual discharges and corrected corresponding weighting factors.