Optimization of EDM process using grey-fuzzy approach

The research investigated the optimization of various performance features on the basis of a gray-fuzzy analysis. The goal was to generate an intelligent system for the optimization of electrical discharge machining based on fuzzy logic and gray analysis. Taguchi's L9 experimental design was used as the research methodology. Two input parameters were selected, namely, discharge current and pulse duration. On the other hand, the material removal rate and surface roughness were taken as output machining performances. Depending on the response of the output performances, the input parameters are selected by applying the gray relation grade and signal-to-noise ratio strategy as performance index. The system is set up according to the following criteria: maximum material removal rate and minimum surface roughness. Based on these criteria, the optimal parameters were obtained, i.e. a discharge current of 5 A and a pulse duration of 5 μ. This combination results in a high gray fuzzy degree of 0.521, which is close to the reference value. Considering the results of the validation experiments, it is concluded that a gray-fuzzy approach can be successfully applied to obtain the optimal combination of influential control parameters.