Comparative Analysis of MCDM Techniques for EDM of SiC/A359 Composite

The aim of the study is to predict the optimal machining conditions in electrical discharge machining (EDM) of particulate-reinforced metal matrix composites (30 vol% SiC/A359). Three independent machining variables viz: current, pulse-on time and pulse-off time are investigated to encompass the EDM performance in terms of induced residual stresses on the machined surface, tool wear rate and material removal rate. The L9 orthogonal array is employed as an experimental plan. The responses results are globally optimized using desirability function approach and lexicographic goal programming (LGP) approach to predict the ideal parametric combinations for the machining of selected composite material. It was observed that both the techniques give a nearly identical optimum solution, i.e. the optimal predicted process parameters value deviation varies from 0 to 1.82%. However, LGP technique is the simplest priority-based approach that can be utilized more efficiently in the complex decision-making conditions. Confirmation test on the predicted optimal results is executed experimentally, and the value of confirmation error is found to be satisfactory.