Abstract

In this study, Topsis and Taguchi method were combined to solve multi-characteristic optimization in die-sinking electrical discharge machining with powder mixed into dielectric fluid (PMEDM). The process parameters considered in this study are electrode material, workpiece material, electrode polarity, pulse on time (ton), pulse off time (tof), current (I) and titanium powder concentration. The experimental results showed that I, electrode material, ton, electrode polarity, powder concentration, interaction between the worrkpiece material and titanium powder concentration, and interaction between the electrode material and titanium powder concentration are the main factors influenced the S/N ratio of C*. The powder concentration is the most significant parameter to S/N ratio. The optimal process parameters include SKT4, Cu (-), ton = 5 s, I = 4 A, tof = 57 s, powder concentration is 10 g/l. The optimal values include surface roughness (Ra = 2.34 m) and microhardness of machined surface (HV = 904.96 HV). However, the optimum results obtained by ANOVA analysis show that Taguchi- Topsis integration to optimize multi-characteristics of PMEDM using Ti powder is not really appropriate.