Research on short electric arc–electrochemical combined machining performance of Ti–6Al–4V alloys using different electrode materials

Short electric arc–electrochemical combined machining (SEAECM) involves both short electric arc discharge and electrochemical dissolution processes, and the choice of electrode materials has an important impact on the respective machining performance of short electric arc machining (SEAM) and electrochemical machining (ECM). Therefore, this research compares the performance of three commonly used low-cost materials (brass, copper, and graphite) as electrodes in SEAECM. The effects of different process parameters (voltage, duty ratio, electrolyte concentration, and feedrate) on the material removal rate, electrode volume wear, surface roughness, and dimensional accuracy errors of the three electrodes in SEAECM are also investigated to determine the applicable occasions for different electrode materials. The results show that the physical properties of the electrode materials such as resistivity, thermal conductivity, and melting point have a significant effect on the machining results. The brass electrode has the highest wear and the lowest material removal rate for all parameters. The copper electrode has the most balanced machining performance, especially at low discharge energy, with low electrode wear and good surface quality. Graphite electrode shows machining potential at high discharge energy, but still requires coordination of SEAM and ECM to improve the surface quality. Overall, in SEAECM, the copper electrode is suitable for high surface quality machining at low discharge energy, and the graphite electrode is suitable for efficient and medium quality machining at higher discharge energy.