Improvement on machining performance in EDM slicing by specifically designed thin foil electrode

Abstract

The use of thin foil EDM slicing is developing as an alternative method for the slicing of single crystal silicon carbide (SiC). Aiming to improve the machining rate and kerf width accuracy, two alternatives are proposed: reduction of the tool electrode side surface area and insulation of the tool side surface. For the former, a foil electrode with holes is proposed. With this electrode design two effects are expected: reduction of kerf width, due to the decrease of the possibility of side surface discharges, and the enhancing of machining rate, due to the improvement of flushing conditions. For the latter, insulated resin was coated on the foil electrode surface, mainly for avoiding the side surface discharges. Moreover, with the objective of enhancing flushing conditions, the effect of jump motion is also studied. The slicing process has been performed by applying a relative motion between a tensioned foil electrode and a workpiece. The results discussion has been focused on kerf width value, machining speed and electrode wear.