Analysis of Different Tool Material On MRR and Surface Roughness of Mild Steel In EDM

In this study, experiments were performed todetermine parameters effecting surface roughness (SR)along with structural analysis of surfaces with respect tomaterial removal parameters. Experimental work wasconducted on Mildl steel with copper, brass and graphiteas tool electrodes with kerosene oil as dielectric fluid.The data compiled during experimentation has beenused to yield responses in respect of material removalrate (MRR) and SR. Detailed analysis of structuralfeatures of machined surface was done by usingScanning Electron Microscope (SEM) and opticalmicroscope to understand the mode of heat affected zone(HAZ), which alternatively affects structure of machinedworkpiece and hence tool life. While investigatingelectric discharge machining (EDM) surface bymicrographs, it was observed that molten mass has beenremoved from surface as ligaments and sheets. In somecases, it is removed as chunks, which being in moltenstate stuck to surface. All three specimens machined bydifferent electrodes showed different pattern of HAZs.