PARAMETRIC INVESTIGATION AND OPTIMIZATION OF NEAR DRY EDM

Abstract

The objective of the present research endeavor is to investigate the influence of process parameters on gaseous emission produced by Wet EDM process and compared it to Near dry EDM process (NDEDM). A setup was fabricated in house. This setup was attached on a diesinking EDM. A pilot experimentation was piloted on HSS by means of Wet EDM and NDEDM to check the achievability of the setup. After endorsing the repeatability of the setup, value of input parameters was decided. Taguchi technique was used to find an optimal setting of the process parameters. Optimum value of peak current and pulse on time may possibly prime considerable drop in productivity. So it was found that mere optimization of process parameters is not a feasible solution for environmental and health safety related exposure from an EDM process. Gas chromatography together with mass spectrometry (GC-MS) has been carried out to analyze the components of gaseous emission. .The effect of pulse current, pulse on time (TON), pulse off (To ) setting were investigated for the two EDM processes for drilling on HSS under the same condition. It was found that gas emission concentration (GEC) is very high and MRR was found lower in Wet EDM process as compared to Near dry EDM. Peak current and TOFF appeared the most significant factor in Wet EDM. GEC) increased with increase in peak current and reduced with reduce in TON. TON followed by peak current appeared significant factor in Near dry EDM. Increased in pulse on time reduce GEC up to a certain level and then increased with increase in TON. Peak current was the most significant factor related to MRR in both type of EDM process. A significant fraction of emission of reaction products of dielectric fluid was found that included high molecular weight hydrocarbons, siloxane, esters and other reaction products. Environmental impact, health and safety issue of worker is outlined as well.