Behavior of Multi-Cathode-Arrays with differentiated current for the Electro-Chemical Machining

Abstract

ECM Productivity is essentially determined by the current used, and in micromachining, the effective current density limits the magnitude of the current. One way to increase the productivity of the micro ECM is to use multiple cathodes. It must be differentiated whether all cathodes are supplied with one process energy source (PES) or each cathode receives its own PES. The paper firstly shows the main differences between the single and multiple current loads and highlights the problems of multiple current supply. The deciding factor is the transfer impedance between the different cathodes. This impedance is determined by the effective areas of the two cathodes and the impedance of the insulating material. In particular, it must also be noted that the insulation thicknesses are only in the range of a few hundred micrometers. Second, the effects of the parasitic elements on the pulse formation at the cathodes are shown by means of an equivalent circuit. From the results of these simulations, the control parameters and their magnitudes for the synchronization of the PESs are derived. For selected case studies, the influences on the current and voltage pulses of the individual cathodes are shown and necessary regulations are shown. The advantages of the multiple arrangement of cathodes with different current supply is that for the multiple machining higher accuracy can be realized, the productivity increases and very different processing cases can be treated simultaneously.