Electrochemical machining under orbital motion conditions

The range of practical applications of electrochemical machining (ECM) is limited by relatively low machining accuracy, specially in cases of complicated shapes. One of the major problems is the generation of spikes which delay the accuracy of the process. The problem is strongly exaggerated if the tool includes multi-electrolyte holes. Moreover, additional machining processes will be needed to remove the resultant spikes. In the present work, tool orbital motion has been proposed as a new technique to enhance the ECM accuracy and to eliminate the presence of the spikes. A special test rig has been constructed for the orbital motion process. A theoretical model has been derived to predict the shape of the frontal zone, the effective machining time and the effective feed rate. The obtained results are an endeavor to provide the ECM tool designer with useful information to enhance the process accuracy. Furthermore, the results facilitate the utilization of the ECM process in die sinking and mold industry. The effect of the applied voltage, feed rate, and tool eccentricity on the spike formation are also presented.