Articles | Volume 8, issue 2
Research article
20 Sep 2017
Research article |  | 20 Sep 2017

Comparative experimental investigation and gap flow simulation in electrical discharge drilling using new electrode geometry

Ali Tolga Bozdana and Nazar Kais Al-Karkhi

Abstract. This study presents experimental and numerical investigation on the effectiveness of electrode geometry on flushing and debris removal in Electrical Discharge Drilling (EDD) process. A new electrode geometry, namely side-cut electrode, was designed and manufactured based on circular electrode geometry. Several drilling operations were performed on stainless steel 304 using rotary tubular electrodes with circular and side-cut geometries. Drilling performance was characterized by Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Tool Wear Ratio (TWR). Dimensional features and surface quality of drilled holes were evaluated based on Overcut (OC), Hole Depth (HD), and Surface Roughness (SR). Three-dimensional three-phase CFD models were built using ANSYS FLUENT software to simulate the flow field at interelectrode gap. Results revealed that the overall performance of side-cut electrode was superior due to improved erosion rates and flushing capabilities, resulting in production of deep holes with good dimensional accuracy and surface quality.

Short summary
This work investigates the effect of electrode geometry on flushing capability and debris removal efficiency in Electrical Discharge Drilling process. Drilling operations on stainless steel 304 were performed using circular and side-cut electrodes. Experimental results were compared with respect to drilling performance as well as dimensional accuracy and surface quality of drilled holes. Three-phase three-dimensional CFD models were also developed to analyze the flow field at interelectrode gap.