An environment-friendly and sustainable machining method: near-dry EDM

Electric discharge machining (EDM) is one of the unconventional machining methods used in machining difficult-to-cut materials. The EDM process uses hydrocarbons-based dielectrics during machining which produces hazardous gases and creates environmental as well as operator’s health and safety issues. Therefore, the present study explores the sustainable variant of EDM (Wet and near-dry EDM) along with the optimized process parameters (pulse-on-time and pulse-off-time) to achieve low gas emission concentration. Near-dry EDM was performed with two-phase dielectric medium (air and EDM oil) and only EDM oil used in wet EDM. The gas chromatography and mass spectrometry (GC-MS) were effectively employed for analyzing the components of gaseous emission. The investigation showed that near-dry EDM process has reduced 97% gaseous emission with higher MRR compare to wet EDM. This process may be termed as green machining process because of very less or negligible gas emission.