Optimisation of machining parameters using grey relation analysis for EDM with impulse flushing

The present work demonstrates the optimisation process of multiple responses, i.e., material removal rate (MRR) and tool wear rate (TWR) of electrical discharge machining (EDM) by grey Taguchi analysis. The work piece material was AISI P20 tool steel and a cylindrical copper electrode was used with side impulse flushing. The discharge current, pulse on time, work time, lift time, and inter electrode gap (IEG) were the control parameters of EDM. Taguchi method was used to design the experiment using L27 orthogonal array and the effect of the factors on the responses was studied. These results show that MRR decreases with the electrode lift time whereas working time slightly increases it. TWR is directly proportional to work time, and lift time and inter electrode gap has no significant effect on it. The optimal parameter setting for maximum MRR and minimum TWR was obtained by grey relational