A 1D model for prediction of dry electrical discharge machining (dry-EDM) plasma characteristics

Abstract

This paper introduces a one-dimensional (1D) model for predicting the properties of electrical discharge machining (EDM) plasma in the air as the dielectric medium. The model solves the governing equations of particle balance (drift-diffusion) and energy balance to determine key plasma properties, including electron and chemical species density, plasma temperature, plasma potential and current, plasma conductivity, and heat flux to the electrodes, as a function of axial inter-electrode distance and time. Validation studies are conducted using experimental data from the literature to assess the reliability of the model. Specifically, the electron density, plasma temperature, plasma voltage, and discharge current are compared between the model predictions and experimental measurements from the literature, demonstrating the model’s accuracy in capturing complex plasma behavior. Simulation experiments are performed to investigate the impact of two key process parameters, the open gap voltage and inter-electrode gap, on the plasma characteristics. The model offers valuable insights into the effect of these parameters on heat flux and energy consumption during the dry-EDM process, which can lead to improved productivity and energy efficiency.