Evaluation of energy consumption and carbon emission in EDM

Green manufacturing is one of the most important development directions in mechanical processing field. Electrical discharge machining (EDM), one of the non-traditional machining, is increasingly used. However, there were hardly any studies on the evaluation of energy consumption and carbon emissions in EDM. In this study, a quantitative assessment model of carbon emission in EDM was built based on the emission factor method. The tool electrode wear, harmless treatment of residual tool electrodes and working fluid, and electrical energy consumed by the equipment were considered in this assessment model. EDM drilling experiments were conducted to verify the effectiveness of the proposed model. The effects of pulse width, pulse interval, and peak current on machining time, surface roughness, energy consumption, and carbon emissions were analyzed. The CNC system, cooling system, and power supply consumed about 95% of the total energy. In small hole EDM drilling, the total carbon emissions from the preparation and waste residue treatment of workpiece and tool electrode were almost negligible due to the small material removal volume. The carbon emissions generated by electrical energy consumption account for about 50% of the total carbon emissions. Carbon emissions can be minimized to 72 g and energy consumption can be reduced to a minimum of 37.48 Wh when processing a small hole with the diameter of 1 mm and the depth of 6 mm by EDM drilling.