Comparison of measured and simulated crater morphology for EDM

The crater morphology has been investigated in different procedures. An analytical relation between pulse parameters and roughness has been achieved and differences between a single discharge and a sequence of discharges are described. Simulations of thermal-affected zones are identified for a single discharge and a sequence of discharges. The characteristics describing the changed gap conditions of the discharge types in the simulation model are shown. Starting from measured current and voltage curves, the thermal channel base parameters are computed. For single discharges with fixed base localization secure expansion parameters of the discharging channel can be determined if the geometries of measured and simulated thermal-affected regions match. The simulation of moving or jumping bases is considerably more complicated and more time-consuming. The channel movement is determined by more degrees of freedom. These additional degrees of freedom permit multiple solutions and the number of them must be reduced by further limiting conditions. (C) 2004 Elsevier B.V All rights reserved.