Comparative Analysis using Electrical Discharge Machining to Determine the Impact of Powder Particles on Inconel-800

Abstract

Inconel-800 is often used across different industries because of its unique properties, especially its ability to withstand very high temperatures. However, machining Inconel-800 can be quite challenging to conventional machining processes due to its distinctive properties. This paper reports the comparative evaluation of electric discharge machining and powder-mixed electrical discharge machining for machining Inconel-800 using a graphite electrode. FERROLAC 3M EDM Oil and boron carbide powder particles mixed with FERROLAC 3M EDM Oil were used as dielectric for electrical discharge machining and powder-mixed electrical discharge machining, respectively. Similar specifications of work specimens and machining combinations were used for conducting experiments by electric discharge machining and powder-mixed electrical discharge machining. Peak current ‘IP’, pulse-on-time ‘Ton’, and pulse-off-time ‘Toff’ were chosen as variable parameters for conducting experiments according to Taguchi L9 (33), and each experimental run was used for EDM and PMEDM for machining of Inconel-800 to perform the comparative evaluation in terms of material removal rate and tool wear rate. The research findings of this study showed that, in comparison to the electric discharge machining process, the powder-mixed electrical discharge machining process significantly increases the material removal rate and decreases the tool wear rate. The results of this study were further confirmed by confirmation tests. A scanning electron microscope and energy dispersive spectrograph were used to analyze the microstructural analysis and elemental composition of the work specimens.