Electrical Discharge Machining of SiCp/2024Al Composites

In this paper, SiCp/2024Al composites was drilled by electrical discharge machining (EDM) to investigate the effect of different electrode cross-section shapes on material removal rate (MRR). The material removal mechanism (MRM) at different discharge energy were also analyzed by changing the electrical parameters. It is found that the MRR of EDM with tube electrode is 5 times greater than that of with cylinder electrode. Electro-erosion debris filled in the discharge gap makes the tool electrode retreat frequently, greatly reducing the MRR. The MRM includes thermal spalling, melting/vaporization and oxidation. The MRM varies with different discharge energy. Thermal spalling is the main MRM at low discharge energy, while melting/evaporation occupies a dominant position in MRM at high discharge energy. Either low or high discharge energy, oxidation always occurs.