Feasibility of Using CeO₂/Water Dielectrical Nanofluid in Electrical Discharge Machining (EDM)

Dielectrical fluids have substantial impact on the machining performance of electrical discharge machining (EDM). Apposite selection of these fluids enhances the material removal rate (MRR) and microhardness while abating the tool wear rate (TWR) and surface roughness. In the present research, feasibility of using cerium oxide/water (CeO2/water) dielectrical nanofluid in EDM is examined experimentally. A portable EDM has been employed for experimental test, whereby mild steel workpiece and pure copper tool electrode were used. Powder concentration of CeO2/water was varied from 0.0 to 2.0 g/L, while the current, set distance, depth of cut and delay time were kept constant at 0.8 A, 2.0 mm, 0.5 mm and 0.5 s, respectively. Results show that at 0.6 g/L concentration, MRR and machining efficiency is enhanced by 20.04% and 69.68%, while TWR is reduced by 29.25%. Minimum surface roughness is obtained at the concentration of 1.0 g/L with Ra value of 0.22 mu m, whereas with distilled water dielectrical fluid this value is 1.06 mu m. Scanning electron microscopy images confirm that the best surface quality with the least pores and minute microcracks is obtained at 0.6 g/L concentration. Use of CeO2/water dielectrical nanofluid also improved material hardness significantly. While the microhardness number with distilled water is 1.06 HV, it upraised as high as 1.94 HV at powder concentration of 0.6 g/L.