Modeling of the temperature field induced during electrical discharge machining

Abstract

Electrical discharge machining is a process with main thermal active principal. Thus, for example for steel materials it is unavoidable to modify the rim zone of the final workpiece. Knowledge or even prediction of these modifications would improve industrial applications. Basis for this is the information about the time and locally resolved temperature field, which is not available in that form today. Hence the objective of this work is to establish a model of the temperature field within the electrodes rim zone during electrical discharge machining process. In this work, this field is modeled for the electrical discharge machining process based on the measurable discharge energy of a single discharge. First, an energy dissipation model for a single discharge is presented. In the next step, the interaction of two consecutive discharges is analyzed. Both results are the inputs for a macroscopic process model to calculate the temperature field of the whole workpiece. Finally, by coupling this macroscopic temperature field and the single discharge model it is possible to determine the locally resolved temperature field at any time of the process. For typical conditions, it is very unlikely that two discharges affect each other regarding overlaying temperature fields in the micro range but over time, a macroscopic heating could take place depending on the dielectric cooling efficiency.