Optimization of parameters of powder added EDM of Nimonic C-263 using TOPSIS

Electric discharge machining (EDM) is a non-conventional manufacturing process that has several variations, one of which is powder mixed EDM that involves adding small particles to the dielectric. In this present experimental study, titanium powder blended in green dielectric, deionized water with different concentrations has been used for die-sinking EDM of Nimonic C-263. In order to obtain enhanced material removal rate, reduced tool wear rate and lesser surface roughness, relevant input parameters are optimized using TOPSIS. Cylindrical copper rod has been used as the tool electrode and a varying flushing pressure is applied to remove the deposited debris from the machining zone. The optimal parametric values are found to be as follows; pulse-on-time = 4 µs, peak current = 10 A, pulse-off-time = 5 µs, flushing pressure = 1 kg/cm², and powder concentration = 9 g/lit. SEM micrographs indicate that a better surface finish is achieved by increasing the concentration of the powder in the dielectric at lower values of peak current.