Formation and Ejection of EDM Debris

Abstract

This paper presents a theoretical and experimental investigation into the debris formation and ejection mechanism. An expression for the size of a debris particle is derived using the drop formation energy and the kinetic energy of the ejected debris particle. The velocity of the ejected particle is obtained from expressions derived on the basis of the analysis of hydrodynamic propagation of shock waves generated due to electrical breakdown in dielectric. The debris particles were collected by machining AISI 1020 steel under various operating conditions. The projected areas were measured by a microscope following the standard procedure of particle size measurement. The particle size has been found to be log normally distributed. The experimental values of debris size compare well with the theoretical estimation indicating the validity of the proposed analysis.