Thermal modeling of single discharge in prospect of tool wear compensation in μEDM

Abstract

Due to the non-isoenergetic nature of discharge pulses in resistance-capacitance (RC) based micro electrical discharge machining (μEDM), the volume of produced micro-crater by each pulse varies significantly. This fact has driven the researchers in this work to propose an electrothermal principle–based analytical model to approximate dimensional accuracies of such micro-craters. A finite element (FE) simulation considering Gaussian heat flux distribution of single discharge μEDM has been performed at significant input parameters such as discharge energy, capacitance, and open-circuit voltage and compared with analytical simulation results. Upon validation of these simulated results with experimental results, nominal dimensional inaccuracies of 2–11% for a wide range of input parameters have been noticed. This effectively predicted crater dimension from the workpiece can be incorporated in the proposed thermal modeling–based real-time tool wear monitoring and compensation system through a unique strategy, which is discussed at the end.