Optimisation of EDM process parameters for AA7050-10 (WT) % B4C composite through ARAS, grey and Taguchi technique

The present paper discusses the development of AA7050-10(wt.) % B4C composite through flux assisted stir casting method and its machinability using die sinking EDM. Taguchi L-16 orthogonal array were used to perform experiments. Material removal rate, surface roughness and tool wear rate were evaluated as machinability measure by considering the concurrent effect of various process parameters. The collected responses were optimised using additive ratio assessment (ARAS) and grey relation analysis and Taguchi technique. Pulse current of 16 A, pulse on time of 200 mu s, and pulse off time of 30 mu s were obtained as the optimum machining parameters. The validity of the Taguchi analysis was further verified by conducting a confirmation experiment. The error estimation for both methods is less than 5%. However, ARAS method gives the least percentage error than grey relation analysis. Hence, ARAS model is suitable to optimise the process parameters of electro discharge machining.