Accuracy Improvements in ECM by Prediction and Control of the Localisation Effects

The accuracy and precision of electrochemical machining (ECM) can be improved by using pulsed power and narrow inter-electrode gaps « 50 J.lm). The narrow gaps, however, make the control and prediction of the process much more complex than normal ECM. To this end, an empirical model is developed that can graphically represent the characteristic relationships between process parameters such as dissolution efficiency, current density, electrolyte concentration and pulse duration in narrow electrolytic gaps. This graphical technique facilitates new applications of high precision ECM (dimensional accuracy ± 5 J.lm, surface finish 0.03 J.lm Ra) by predicting and controlling the dissolution and localisation effects.