Predicting the Influence of Electrical Discharge Machining (EDM) Parameters on the Finished Work Surface in CK45 Steel

CK45 steel is a suitable material for the manufacturing of forging dies. This paper investigates the influence of electrical discharge machining (EDM) parameters including voltage, current, on-time and off-time on the microstructure of the machined surface of this material. The process induces thermal stresses that in turn result in the generation of widespread micro-cracks on the surface of the part subjected to spark EDM. The influence of EDM parameters on the quality of the machined surface is explored by performing an extensive experimental program. The impact of EDM parameters on the surface roughness and the intensity of micro-cracks have been evaluated quantitatively using the test results and regression analysis. Predicting the relationship between EMD parameters and the surface quality provides practical means to appropriately decide on the adjustment of process control parameters to their optimum values and hence to achieve the desired surface quality at reasonable manufacturing times and cost.