Optimization of process parameters in powder mixed EDM of H21 hot die steel

Abstract

Electric Discharge Machining (EDM) is one of the most popular machining methods and manufactures dies and press tools because of its capacity to produced complicated shapes and machine very hard material. Intent of present study is to study the effect of different input parameters, namely, tool, current, concentration, pulse on time, pulse off time, powder on the output parameters MRR,TWR and SR. Hot die steel (H21) was is used as workpiece. Copper and tungsten-copper are used as tools. Effect of nickel and chromium powder is analysed in study. ANOVA is used to analyse the results. It has been observed that with addition of powder to dielectrics, there is increase in MRR by 20.34%, decrease in TWR by 45.58% and surface roughness reduces by 17.38%. It improves microhardness of material also.