Electric Discharge Machining of Inconel 718 Under a Distinct Dielectric Medium

Abstract

In this research, an attempt was made to machine the Inconel 718 alloy under varied dielectric medium with the objective of generating wealth from waste and establishing a green environment. Experiments were conducted to analyze the influence of input variables under the EDM oil, pure sunflower oil, used sunflower oil, palm oil and ground nut oil insulating medium. Five different tools namely copper, brass, aluminium, copper—graphite and aluminium—graphite was utilized for investigation and experimental runs were designed using Taguchi mixed orthogonal array. The results revealed that the characteristics of the dielectric fluid influences the spark generation and machined cycle time. The findings divulged that dielectric fluid with a high density facilitates flushing, low specific heating distributes heat uniformly and low carbon content eliminates black spots. Electrode with low thermal conductivity dissipates more heat and low latent heat of fusion erodes excessively. Micro pits, globules, angled and clouded blobs, black spots, material dunes and redeposited material are the various features observed on the machined surface texture.