Effect of the electrode radii under different machining conditions in different positions along the flushing path

Abstract

Electrical discharging machining is a process that uses high-frequency electrical discharges to generate heat, melting and vaporising the workpiece material. Melted material is flushed away by dielectric flushing. However, only part of the molten material is removed, the remaining material resolidifies discharge craters, which affects the integrity of the workpiece. This paper discusses how the flushing flow and the radii of electrode under different machining conditions can affect the roughness and affected layer. Rectangular cavities were machined with a copper electrode in AISI H13 steel. Unilateral side flushing with an immersion flushing was used. An analysis of variance was used to verify the statistical relevance of the results. The obtained data appointed that, under the flushing condition used, independent of the electrode radii, some significant differences were found in roughness and scanning electron microscope (SEM) images. No difference was found in affected layer thickness in different analysed positions of flushing path.