Anode Power Deposition in Dry EDM

Dry electrical discharge machining (DEDM) has been developed as an environmentally friendlier alternative to the traditional EDM in oil-based dielectric. Proper understanding of the physics of the DEDM discharges is necessary in order to improve this new manufacturing technology, since its workpiece material removal and tool electrode wear mechanisms are governed by plasma-material interactions. The present work proposes the application of theoretical models, numerical simulations, and advanced diagnostics from the field of plasma physics as effective tools to estimate the electric discharge power deposition onto the anode workpiece in DEDM. Collisional-radiative models are used here to calculate several plasma properties, from which the anode power deposition can be estimated. In addition, electrical circuit simulations, which use a modified Cassie-Mayr model, calculate the fraction of the total electric discharge power that is consumed by thermal conduction into the anode electrode material. The methods proposed in the present work provide fundamental information for further workpiece material erosion modelling and simulation under different DEDM processing conditions.