Effect of wire electrical discharge machining (WEDM) parameters on surface integrity of nanocomposite ceramics

Conductive TiN/Si3N4 nanocomposite ceramics hot pressed composites were processed by wire electrical discharge machining (WEDM) and their microstructure was investigated. The dependence of surface texture, surface roughness, and materials removal rate on wire electrical discharge machining conditions including power transistor numbers and pulse off-time was also analyzed. More power transistor numbers result in greater material removal rate and greater roughness. More pulse off-time result in lower material removal rate. The surface microstructures machined by the new process were examined with a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), and X-ray diffraction (XRD). The results show that the TiN/Si3N4 nanocomposite ceramics are removed by melting, evaporation and thermal spalling; the material from the wire electrode is transferred to the workpiece, and a combination reaction takes place during wire electrical discharge machining of the TiN/Si3N4 nanocomposite ceramics.