Atomized Dielectric Spray-Based Electric Discharge Machining for Sustainable Manufacturing

Abstract

A novel method of using atomized dielectric spray in micro-electric discharge machining (EDM) (spray-EDM) to reduce the consumption of dielectric is developed in this study. The atomized dielectric droplets form a moving dielectric film up on impinging the work surface that penetrates the interelectrode gap and acts as a single phase dielectric medium between the electrodes and also effectively removes the debris particles from the discharge zone. Single-discharge micro-EDM experiments are performed using three different dielectric supply methods, viz., conventional wet-EDM (electrodes submerged in dielectric medium), dry-EDM, and spray-EDM in order to compare the processes based on material removal, tool electrode wear, and flushing of debris from the interelectrode gap across a range of discharge energies. It is observed that spray-EDM produces higher material removal compared to the other two methods for all combinations of discharge parameters used in the study. The tool electrode wear using atomized dielectric is significantly better than dry-EDM and comparable to that observed in wet-EDM. The percentage of debris particles deposited within a distance of 100 μm from the center of EDM crater is also significantly reduced using the spray-EDM technique.

Sustainable Electrochemical Micromachining Using Atomized Electrolyte Flushing

“…In the study of atomized spray-based EDM machining, the claimed values of W e and K m were 36.61 to 212.62 and 17.71 to 53.16 respectively. 29 In the present study, the values of K m number are <57.7 and the values of W e are >10. These values differ from those reported in the study of Pattabhiraman et al (2015) 29 since the fluid properties, atomizer type, and pressure range in this study are different.…”

“…36 Pattabhiraman et al obtained the values of W e and K m for dielectric droplets in EDM for ensuring to be in the spreading regime for different spray pressures. 29 In order to ensure the droplet-surface interaction to be in the spreading regime, the values of W e , R e , and K m are calculated with the above information for pressures of 1 bar, 2 bar, and 3 bar at 20 mm downstream distance (Shown in Table I). The mass flow rate of the atomized electrolyte is measured to 56 ml min −1 and spray length 20 mm is considered since the spray is impinged from the height of 20 mm.…”

“…Incorporating an atomized fluid-based coolants not only improves the environmental sustainability of the process but also decreases the production cost as demonstrated by Gupta and Laubscher. 27,28 In the domain of advanced machining processes, atomized dielectric spray-based electric discharge machining (EDM) is introduced by Pattabhiramn et al 29 This study claimed that discharge energy, MRR, tool wear resistance improves significantly in spray-EDM. Liu et al proposed mist-jetting-based electrochemical discharge machining (ECDM) with a slotted grinding wheel.…”

Brief Chronological Study of the Evolution of Electrical Discharge Machining

“…Ahad Gholipoor (2015) carried out comparative study of wet, dry and near dry EDM of SPK steel and suggested wet EDM for rough machining and near dry EDM for finishing [57]. Arvind Pattabhiraman et al (2015) studied the near dry EDM using atomized spray of EDM oil and suggested that in spray EDM discharge energy increased by 37% and volume of material removed increased by 78% [60]. Krishnakant Dhakar et al (2016) utilized glycerin in near dry EDM and achieved promising results owing to high viscosity of the glycerin and better surface finish [74].…”

Experimental investigation and performance enhancements characteristics of gaseous assisted powder mixed near dry electric discharge machining

“…15 It was observed that spray Electric Discharge Machining was more efficient in terms of high MRR in comparison to wet and dry Electric Discharge Machining, for all possible set of discharge parameters. 16 It was also stated that in comparison to other gases as dielectric medium, nitrogen plasma jet was most effective in increasing machining efficiency. 17 While the surface finish (Ra) obtained on machined parts by oxygen assisted DEDM was very low due to the fact that oxygen assisted EDM resulted in high MRR which means that the craters produced over the surface of the machined workpiece will be deeper and wider which results in poor surface finish.…”