EDM of Aluminum Alloy 6061 Using Graphite Electrode Using Paraffin Oil and Distilled Water as Dielectric Medium

Abstract

EDM machining of Al 6061 was performed under varying conditions of pulse current and pulse duration. Graphite was used as an electrode material with distilled water and paraffin oil as two different dielectric mediums. The aim is to characterize the surface integrity produced as a result of EDM machining under both varying electrical and non-electrical parameters as it is important in determining the service life of EDM machined components. The vertical, horizontal and corner surfaces are studied independently for each single set of conditions. The average white layer thickness (AWLT) and surface roughness was found to be dependent on pulse current values and pulse duration. The dielectric medium also has an influence on the thickness and nature of white layer. It was found that the thickness and nature of the white layer formed from distilled water is different from that of paraffin oil. New methods of AWLT and surface roughness measurement through an optical microscope are described. The surface roughness method developed was calibrated against an identical surface roughness tester. Finally, material removal rate, tool wear rate, the presence of micro cracks, voids and globules were compared for different conditions and conclusions were drawn according to the actual physical conditions during machining.

Effect of Distilled Water and Kerosene as Dielectrics on Machining Rate and Surface Morphology of Al-6061 During Electric Discharge Machining

“…The sudden quenching of material right after liquefaction is the reason for reduced MRR as compared to kerosene. This result were found to be in agreement with previous studies [31,32]. Figure 4 shows the surface morphology produced by the EDM process in distilled water with copper electrode.…”

Experimental Study on the Influence of Machining Conditions on the Quality of Electrical Discharge Machined Surfaces of aluminum alloy Al5052

“…For T on = 100 µs, depicted in Figures 4a and 5a, the WL has an extremely thin and discontinuous profile, having only a few small globule formations. For T on = 200 µs, Figures 4b and 5b, the WL is still thin and discontinuous, but larger globules appear, indicating the simultaneous existence of re-condensed (smaller globules) and incomplete evaporated (larger globules) material formations, observations which are in line with the study of Imran et al [6]. For T on = 300 µs, Figure 4c, the WL profile is thicker and almost continuous, with larger globule formation, and disintegration areas, Figure 5c.…”

“…The material removal rate (MRR), the tool wear ratio (TWR), and the surface roughness (SR) were calculated or measured. Imran et al [6] studied the machining of Al6061 with EDM under a variety of pulse current (6-12 A) and pulse-on time (60-200 µs) conditions, using graphite electrode and two different dielectric mediums. MRR, TWR, surface integrity in terms of the average white layer thickness (AWLT), and the SR were calculated.…”

Effect of SiC Particle Incorporated Dielectric Medium on Electrical Discharge Machining Behavior of AA6061/B4Cp/SiCp AMCs

“…Nitrogen and argon gas was found to be the finest dielectric medium for removing more material and producing the highest surface quality. Imran et al [22] used distilled water and paraffin oil as dielectric media to manufacture AA6061 aluminium alloy. Using purified H 2 O as dielectric resulted in a thicker white coating than using paraffin oil.…”