The last decade has seen an increasing interest in the novel applications of electrical discharge machining (EDM) process, with particular emphasis on the potential of this process for surface modification. Besides erosion of work material during machining, the intrinsic nature of the process results in removal of some tool material also. This paper proposes an optimization methodology for the selection of best process parameters in electro discharge machining for surface modification of 40CrMnMoS86 hot worked steel parts. The experimental data are gathered based on Taguchi L36 design matrix. The tests are conducted under varying peak current (I), voltage (V), pulse on time (Ton), pulse off time (Toff) and duty factor ().The effects of these input parameters are then determined on the most important process output response, surface roughness (SR). Using these data and the simulated annealing algorithm, the process parameters can be set to achieve desired surface roughness. Next, analysis of variance (ANOVA) and F– test have been used to evaluate the relative significance of process variables affecting process outputs. A verification test is also performed to verify the accuracy of optimization procedure in determining the optimal levels of machining parameters. The results indicate that Taguchi technique and simulated annealing algorithm are quite efficient in determining optimal process parameters for optimization of surface finish in EDM.

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