MULTI-RESPONSE OPTIMIZATION OF PROCESS PARAMETERS IN DIE - SINKING ELECTRICAL DISCHGAGRE MACHINING USING TITANIUM POWDER INTO DIELECTRIC FLUID BY TOPSIS - TAGUCHI

Abstract

In this paper, the two indicators: Surface roughness (R_a) and micro- hardness (HV) of machined surface after die- sinking electrical dischagre machining using Titanium (Ti)  powder mixed into dielectric fluid has been selected to optimize simultaneously of process parameters. Taguchi method and Topsis method are combined to solve the multi-indicators optimization problem. The process parameters to investigate the following: Workpiece material, electrode material, electrode polarity, pulse-on time, current, pulse-off time, and Ti powder concentration. Results showed that Ti powder mixed into dielectric fluid, it has improved the efficiency of multi- indicators optimization in die- sinking electrical dischagre machining. Optimal parameters are SKT4, Cu (-), T_on = 5ms, I = 4A,
T_of = 57ms, Ti powder concentration is 20g/l. Optimal value are  Ra = 1.45mm and HV = 649.5HV. The surface layer at optimum conditions is also analyzed and its result are good.