Response optimization and machining microslit arrays in molybdenum through micro-EDM

Prominent applications of microslit-type geometries on molybdenum thin sheets include X-ray collimators and sustained discharge reactors. The parametric analysis of process variables affecting responses using a tungsten carbide micro-electrode during microdrilling and process optimization, the fabrication of microtools for machining microslits by considering the overcut at optimal conditions to attain the required slit width, and the machining of an array of slits using the fabricated microtool under the optimal conditions make up this research. Capacitance and voltage are the most influential process variables according to ANOVA. The process is optimized by overall evaluation criteria. The optimal condition when all responses are given equal weightages is obtained at capacitance = 100 pF, voltage = 80 V, feed rate (FR) = 10 µm/s, and tool rotational speed (TRS) = 2000 rpm. The average slit width at entrance and exit sides are measured to be 514.70 µm and 493.51 µm, respectively. The optimal condition by balancing machining efficiency and dimensional precision is found at capacitance = 10,000 pF, voltage = 200 V, FR = 40 µm/s, and TRS = 2800 rpm. The average slit widths at the entrance and exit sides are 506.72 µm and 478.02 µm, respectively, at that condition.