Enhancement of Surface Crack Density Producedby EDM Using Hybrid Machining

Abstract

The present work is aimed to improve the surface cracks density of electrical discharge machining (EDM) by Electrical Discharge Machining (EDM)/Electrochemical Machining (ECM) 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. 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 response surface methodology (RSM), these controllable effects include: pulse current, pulse on time, pulse off time, gap, voltage, and electrolyte concentration on surface cracks density (SCD). It has been noticed that model has been developed by RSM adequacy is acceptable because the coefficient of determination is closest to one for SCD, whereas the optimal solutionachieved by Desirability Function Analysis (DFA) are (current=42A, pulse-on time=100,and pulse-off time =50)in addition to that, the generated surface doesn’t have any crack which has been generated via EDM are removed entirely through ECM finishing.