Multi-criteria optimization method in micro-EDM using TiN coated tungsten carbide electrode

Even though the coated electrode can enhance the machining efficiency in micro-EDM process, it is essential to introduce optimization approach for further enhancing the process. Hence the present study was performed with multi-criteria optimization in micro-EDM using TiN coated tungsten carbide electrode for machining Ti-6Al-4V. The Z coordinator (Z) and tool wear rate (TWR) were used as the quality parameters to evaluate the machinability. The voltage (U), capacitance (C) and spindle rotational speed (n) were considered a the technological parameters. The Technique for order preference by similarity to ideal solution (TOPSIS) method was a suitable solution to determine the optimal result with the help of S/N analysis and by ranking. It was found that capacitance has more significant nature in the process. The optimal process parameters combination was found with better accuracy and lower prediction error of 1.03%. The better machined surface quality was also observed under optimal conditions.