Experimental research on the influence of dielectrics on short electric arc machining of GH4169

Short electric arc machining (SEAM) is a novel electrical discharge machining method with low voltage and high current. Due to the narrow discharge gap, chip removal is difficult and short circuits can easily occur during processing. Dielectrics have an important role in SEAM as they influence chip removal. As such, selecting appropriate dielectrics can improve machining efficiency. This work seeks to reduce the occurrence of the above phenomena and improve machining efficiency by analyzing the working medium of air, tap water and air-water mixture. Effects on material removal rate, tool mass wear ratio (theta), surface roughness, macroscopic difference of GH4169 surface, interelectrode voltage-current waveform, surface micromorphology, debris morphology and the cross-sectional morphology are evaluated. The experimental results show that when air-water mixture is used as working medium, the machining efficiency is the highest. To further analyze the findings, the dielectric breakdown mechanism is examined, which provides an excellent working medium for more efficient SEAM process.