Study on Parameter Determination for ECM Equivalent Circuit and its Verification

The analysis of the electrochemical machining (ECM) model expressed by an equivalent circuit is helpful to understand the ECM characteristics, such as the removal rate and machining accuracy. Although the performance of an electrochemical cell can usually be represented by an equivalent circuit, the equivalent circuit for electrochemical machining (ECM) has not been well established. The reason is that the ECM phenomenon is much more complicated due to the anodic dissolution and other reactions. In the previous study, a method to determine each parameter in the equivalent circuit was proposed by comparing the computed current waveforms with the experimentally obtained ones, using genetic algorithm. However, the parameters of the anode and cathode could not be distinguished, because materials for both electrodes were the same. In this research, experiments and computations were conducted when different materials and combinations were used. As the result, the parameters of the anode and cathode are successfully distinguished, by comparing each material combination. Moreover, in order to prove the credibility for the parameter determination, experiments under different experimental conditions were carried out. In experiments, the applied voltage, the kind of electrolyte, the electrolyte concentration and the gap-distance was changed respectively. The parameters determined under those conditions were compared and discussed with some generally-known phenomena. As the result, since the obtained parameters could be well explained by the generally-known phenomena, the credibility was confirmed.