Research on the mechanism and process of polycrystalline diamond by EDM

Traditional electric discharge machining (EDM) uses a Cu electrode to machine polycrystalline diamond (PCD), but it is hampered by poor machining efficiency and quality. During this study, a Cu-Ni electrode was used to machine PCD with graphene power suspended in the dielectric. The surface properties and machining mechanism of PCD under different parameters were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The surface quality and machining efficiency were analyzed by quantifying the surface roughness (SR) and material removal rate (MRR). The results demonstrated that the MRR of the Cu-Ni electrode increased by 65% when compared with that of Cu electrode at low discharge parameters, with the MRR of Cu-Ni electrode improved by a further 87% when graphene was added to the dielectric. Raman spectroscopy and XRD analysis showed that graphitization of PCD diamond processed by the Cu-Ni electrode was greater than that of the Cu electrode, and the addition of graphene further facilitated this process. The machining efficiency and quality of PCD in EDM can be greatly improved with the use of Cu-Ni electrode and graphene suspended in the dielectric.