Experimental Analysis of the Machinability of 94 WC–6 Co by Die-Sinking EDM

Cobalt-bonded tungsten carbide (WC-Co) is widely used in heavy-duty machining applications due to its exceptional hardness and wear resistance, and it is increasingly being adopted in industries such as aerospace and the automotive sector, among others. Its superior mechanical properties make it difficult to machine with conventional methods such as turning or milling. Electrical Discharge Machining (EDM) has emerged as an efficient alternative, as it allows for the machining of hard materials to be carried out without direct contact between the tool and the workpiece, provided that the material has sufficient electrical conductivity. In this study, a multilevel Design of Experiments (DOE) was conducted to analyze the influence of EDM parameters-specifically, the current intensity and pulse time-on the surface roughness (SR), electrode wear (EW), and material removal rate (MRR) for 94WC-6Co. The results indicate that the current intensity was the most significant factor across all responses, while the pulse time played a secondary role. Surface finishes as low as Ra = 0.47 μm were achieved at I = 2 A and t_i = 10 μs. For each outcome variable, mathematical models were obtained in order to improve the EDM processes and better understand the machining of WC-Co.