Parametric Optimization of Micro Drilling on Brass in Micro Electrical Discharge Machining

Micro electrical discharge machining (mu EDM) is a variant of electrical discharge machining (EDM) used to produce microfeatures in the range of micrometers. It is an efficient machining process used for fabrication of microcavities with various advantages resulting from its inherent characteristics of being non-contact and removing material by thermal process. This work mainly focuses on drilling of microholes on brass sheet of 40 mu m thickness using tungsten tool electrode of 485 mu m diameter. Process parameters such as voltage, capacitance, feed rate and tool rotation are varied during experimentation. Taguchi L-16 orthogonal array is incorporated to study the effect of process parameters on the response measures: machining time and overcut. The process parameters are optimized for lower machining time and overcut. Machining time of 54 s and overcut of 10 mu m is achieved at optimum parametric condition of machining time and overcut respectively. Further, analysis of variance (ANOVA) is employed to evaluate the significance of process parameters on the response measures.