4. Fabrication of Micro-holes Array Through Multiple Electrodes with Distributed Μ-Pulsed Electrochemical Machining

Electrochemical micro-machining (ECM) has tremendous potential on account of versatility of its applications in different domains of engineering. Micro-machining of large surface area by ECM process is one of the challenging tasks on the current date—such as production of perforated sheets for filtering specific dimensioned micro-particles needs to generate millions of identical micro-holes in small area. As in the case of electrochemical micro-machining (ECMM), high-resolution micro-features are achieved when a low duty cycle pulsed voltage is used. When a low duty cycle pulsed voltage is supplied for machining of micro-holes, the pulse off time will increase the effective machining time by significant amount. To minimize the machining time when machining large number of micro-features, we hypothesize multiple electrodes EC drilling with sequentially distributed micro-second pulses. By providing the sequential firing-order-based pulse distribution, pulse off time is zero because at any instant at least one or more number of electrodes would be in the pulse on mode. This study outlines a numerical and experimental study of micro-holes array drilling through multiple electrodes in ECM process. A novel approach of sequential pulse distribution to each electrode is studied to improve the machining efficiency by reducing the machining time. Simultaneously four electrodes of 65 μm tip diameter are used to pierce micro-holes in stainless steel sheet of 100 μm thickness. Micro-holes of 121 and 149 μm diameters with spacing of 200 µm are machined. The study shows there is a close fit between the simulated and experimental diameters of machined holes.