Enhancement the Thermal Effects Produce by EDM Using Hybrid Machining

Abstract

The present work is aimed to improve the thermal effects of electrical discharge machining (EDM) by EDM/ECM hybrid process. A hybrid method of EDM-ECM combined processing involve EDM shaping as well as electrochemical machining (ECM) finishing, also, they are conducted in sequence one same machine tool, same electrode, yet on the different dielectric. Concerning the process of EDM, the material will be removed via the vaporization and melting throughout all electric discharges. Thus, thermally damaged layers make the machined surface. In this study, the used workpiece material is the A2-Tool Steel material, while the electrode material is copper. The influence of controllable parameters could be identified via RSM, which is an abbreviation for Response surface methodology, these controllable effects include: pulse current, pulse on time, pulse off time, gap, voltage, and electrolyte concentration on white layer thickness (WLT) and Surface Roughness (SR). It has been noticed that model adequacy is acceptable because the coefficient of determination is closest to one for WLT and SR, in addition to that, the generated surface doesn't have thermally affected layers as the SR and recast layers which have been generated via EDM are removed entirely through ECM finishing.