A comprehensive investigation into dry and near-dry EDM towards green manufacturing: a conceptual review

Dry and near-dry electrical discharge machining (ND-EDM) is an important advanced machining process and variant of traditional electrical discharge machining (EDM) to machine the complicated profile from hard materials in manufacturing industries. The gas now replaces the dielectric fluid (liquid), and a minimum quantity of liquid is mixed with gas, which is now proposed as a green manufacturing process. Various gases and a mixture of liquid have been used as the dielectric fluid in near-dry EDM. Dry and ND-EDM cause better debris removal and flushing due to lower viscosity of gas. The current article discusses a critical review of dry and ND-EDM, including various machining characteristics, process parameters, and different optimisation techniques. This article provides a basis for understanding the current status of research and development activities. It summarises many future research scopes and past research done with challenges in ND-EDM to promote green manufacturing for industrial implementation.