Electrical discharge process
At first no current flows, because the dielectric fluid behaves like an insulator.
When the distance between the workpiece and the electrode, i.e. the gap, drops to a certain distance, an electrical discharge is created with a spark.
During the discharge the voltage drops and the current causes a significant rise in temperature at the spark point.
With this process, small amounts of metal on the workpiece melt, break away and vaporize.
Formation of the surface on the workpiece
When the switch opens, the molten material is dispersed like an explosion, the discharge channel is deionized and a small crater remains.
If a series of discharges is applied and the charge-discharge cycles are repeated in a chain, several more craters are formed close to the craters already created. In this way continuous erosion and crater formation take place on the workpiece surface.