Investigation on Influence of Die Electric Medium in Electrical Discharge Machining of Monel 400 Alloy

Abstract

Electrical Discharge Machining (EDM) is a non-conventional thermal energy based erosive process, which primarily applied for machining hard materials. Material Removal Rate (MRR) and surface roughness are the response parameters used to characterize the dielectric nature of the machined surface in EDM process. Addition of ingredients in the dielectric fluid improves the properties of fluid for better machining of the samples. The dielectric fluid medium plays a key role in controlling the electrical discharge and heat absorption, thereby removes the debris and cools the work piece during the machining process. In the current study, comprehensive work is done by investigating the effect of different dielectric fluid medium on machining parameters of EDM process with the addition of different powders in the dielectric fluid, which results in high precise and better topography in the machined part surface. Addition of powders such as Titanium (Ti), Silicon (Si), Graphite (Gr), Copper (Cu) and Aluminium Oxide (Al2O3) in dielectric fluid increases the convection property in the work piece tool interaction with increase in the micro-hardness of material. This work analyses the performance study of Electrical Discharge Machining (EDM) of Monel 400 alloys, which can be improved by adding metallic powder into the dielectric medium. Material Removal Rate (MRR) is measured in the samples machined out of EDM process. In addition, Taguchi L27 Orthogonal Array is formulated for conducting machining in a sequential order to understand the implications of machined process parameters on the material removal rate over different dielectric mediums. It is found that the Aluminium oxide, graphite powder mix with EDM oil gives better material removal rate and less machining time. Furthermore, the introduction of Cu powders in the dielectric fluid provides better machinability response parameters. But it is preferable to parts with high slenderness ratio especially holes.