Numerical Modelling and Simulation of Micro Electro-Discharge Machining: Prediction of Crater Size

This paper introduces an analytical model rooted in electro-thermal theory to estimate the size of micro-craters in micro-electrical discharge machining (mu-EDM). Addressing the challenge of the stochastic nature of the mu-EDM process, the model incorporates voltage and capacitance to predict crater size on the workpiece caused by individual discharges in micro-EDM. The simulation involved using COMSOL Multiphysics 5.6 software to simulate a single discharge in the mu-EDM process. This simulation accounted for the phase change material properties and the expansion of the plasma channel radius over time. The study further developed a numerical analysis to assess how input parameters (capacitance and voltage) influence the efficiency of the plasma channel in removing molten material. A regression model for plasma flushing efficiency (PFE%) based on experimental and numerical results was introduced to predict the actual crater size. The findings indicate contrasting effects of capacitance and voltage on plasma flushing efficiency. Specifically, an increase in capacitance contributes to an increase in plasma flushing efficiency.