An experimental investigation on magnetic field assisted EDM process for Inconel 625 using bio dielectric fluid

Abstract

The present research work evaluated the effect of magnetic field intensity and bio-dielectric fluid on EDM performance. Two electrodes of Cu having different densities (0.004795 and 0.007316 gm/mm3) and a solid Cu rod (0.008947 gm/mm3) were used as tools. The study develops tools of different densities with the atomic diffusion additive manufacturing process. It uses permanent magnets to create two magnetic field intensities (0.396 T and 0.665 T). The process variables selected were discharge current, pulse on-time, pulse off-time, and electrode density, and their effect on material removal rate, tool wear rate, surface roughness and overcut were studied. The pilot experiments were performed using one factor at a time approach to finalize the range and level of input parameters. The main experiments were designed as per BBD methodology using Design expert-13. The experiments demonstrated that bio-dielectric fluid produced better performance than ED Moil. While with magnetization, higher MRR, lower TWR, lower Ra, and higher DOC values were observed. The effect of the magnetic field on the EDM performance was the same for both fluids. The experimental data was analyzed in terms of regression models using ANOVA. It was observed that the output parameters increased with the discharge current for both fluids and magnetic field strengths. The high pulse duration resulted in slightly higher MRR, TWR, Ra, and DOC. The effect of pulse off-time was insignificant. TWR decreased with density of the electrode while DOC increased. Optimization of the process has been conducted followed by confirmation experiments to validate the result. The research work established the feasibility of the use of used cooking oil biodiesel as the dielectric fluid with the benefit of reduction cost and related environmental benefits. newline