Discharge characteristics of W-Cu electrode in short electrical arc discharge machining of Inconel 718

The current application of short electrical arc discharge machining (SEAM) for cemented carbide removal is limited by its surface quality. In this study, tungsten-copper (W-Cu) alloy materials with different proportions as electrodes were studied by experimental methods. The mechanism of electrical parameters and composition content affecting the processing performance of SEAM was investigated, including surface roughness (Ra), material removal rate (MRR), micro-morphology, and the recast layer thickness (RLT). The results showed that the maximum MRR with W50-Cu electrode was 41 g/min, and the processing performance was the best with W90-Cu electrode in the U of 25 V, F of 2.3 KHz, and D of 55%. The W90-Cu electrode could provide good processing, and a thinner and more uniform recast layer was found on the workpiece surface. Therefore, W-Cu alloy tools are recommended when the hard surface materials machined by SEAM requires higher accuracy and surface finish.