Investigation of biodiesel dielectric in sustainable electrical discharge machining

Limited efforts have been made to transform electrical discharge machining to a green and sustainable machining process. Current electric discharge machining (EDM) processes use hydrocarbon or synthetic-based dielectric fluids. These fluids emit harmful vapors when they break down, raising concerns for machine operators and for the environment. Biodiesel (BD) has similar properties as conventional dielectric and it can be used in place of conventional dielectric fluids. This research aims to study the effects of biodiesel dielectric in EDM process, especially in micromachining. Experiments are carried out in both low and high energy settings, on bulk metallic glass (BMG) and titanium alloy (Ti-6Al-4 V) using 200-μm-diameter electrodes. Canola BD and sunflower BD are compared against conventional dielectric in terms of material removal rate and tool wear ratio. The experimental evidence showed that both canola and sunflower BD are able to outperform conventional dielectric, and thus suggesting that BD has the potential to replace conventional dielectric as to provide a more sustainable machining process in the future.