Investigation of the pre-ignition stage in edm

The pre-phase of electrical discharge in dielectric fluids has been described sufficienly the previous theoretical reflections on spark erosion. For a precise analysis of the anodic and cathodic removal it is necessary to find out, the influence of the boundary layers, the movement of the charged particles in media of different density and the reason for gas development and its time course. Based on the latest theoretical knowledge about the pre-discharge phase and our own basic research results we try to understand the cause-effect-mechanism in the development of charges in either electrolytes or solid dielectric layers. The theoretical reflections are verified by experimental investigations on aspecial singlepulse-equipment with a high-speed-framing camera and by material analyses. KEY NOTES: Electrical discharge, ignition phase, Electrical discharge machining