Characterising Energy Efficiency of Electrical Discharge Machining (EDM) Processes

Energy efficiency in manufacturing has become a critical topic among researchers and industries. As a result, there has been a worldwide effort to improve the transparency of the energy efficiency for all manufacturing activities. The studies of unit processes have provided fundamental knowledge for characterising energy efficiency of manufacturing processes, which has been initially applied to conventional processes (e.g. turning, milling, injection moulding, etc.). However, studies in nonconventional manufacturing processes remain absent. This paper presented an empirical approach to characterise the energy efficiency of electrical discharge machining (EDM) processes. The derived model revealed a reverse relationship between specific energy consumption and material removal rate (MRR). Owing to the stochastic nature of EDM processes, the existing analytical and semi-empirical MRR models cannot practically predict the MRR. Alternatively, the empirical approach was also applied to test different theoretical MRR models and to derive coefficients for prediction purpose. As a result, the combined empirical models can predict the energy consumption of EDM processes with an accuracy of more than 90%. This methodology has been tested and validated for two ram EDM machines.