An investigation into performance of electric discharge milling using slotted tools

The flushing of by-products from the interelectrode gap (EG) of a few microns is the major concern in the electrical discharge machining (EDM). The inadequate removal of debris from the gap causes short-circuits and reduces machining efficiency. Researchers have explored different techniques to enhance debris flushing from the gap. In electrical discharge milling (ED milling), the rotation of the tool along with linear travel is the major driving force for the debris flushing. In this paper, the application of an improvised tool to enhance rotation induced debris flushing is proposed. The flow-fields of dielectric and debris were modeled using computational fluid dynamics (CFD). The simulations results were utilized to optimize the tool geometries. A comparative study of the cylindrical and improvised tool in terms of material removal rate (MRR), tool wear rate (TWR) and surface finish was calculated. Relative to conventional cylindrical tools, the improvised tool enhanced the MRR by 150 %.