Influence of Powder Mixed EDM on the Surface Hardness of Die steel

Abstract

Improving the surface hardness of molds after EDM is still being challenged by many researchers. In this research, an effort was made to enhance the surface hardness of die steel though adding metal powder to dielectric and optimization parameters of EDM. process factors are workpiece types, concentrations, powder types, and electrical variables of the machine. Taguchi’s method has been used to design experiment and the results have been analyzed by ANOVA. The influence of the factors on micro hardness was evaluated though the mean and signal to noise ratio(S/N) of micro hardness. The results showed that, the mixing of Mn powder with insulator fluid results in high micro-hardness compared with aluminum powder, mixed powder of aluminum and manganese, also with pure dielectric. The significant factors for micro-hardness is a powder type (Mn) and has more contribution 43%. The factors of pulse on time and concentration have no significant effect on hardness of mold surface.