Effects of Polarization on Machining Accuracy in Pulse Electrochemical Machining

Electrochemical machining (ECM) is an important processing method for conductive material with high hardness and heat-resistance. However, poor machining accuracy has always been a significant problem in ECM. In order to improve the machining accuracy of ECM, the polarization phenomenon in pulse electrochemical machining and influence of polarization on the machining accuracy were experimentally investigated in this paper. A polarization voltage was detected during the pulse-off time, and the experimental result has demonstrated that using a pulsed-power supply cannot improve the machining accuracy of ECM when there was a polarization voltage during the pulse-off time. Therefore, to reduce the influence of the polarization voltage on the accuracy of pulse electrochemical machining, a novel pulsed-power supply method, which accelerates depolarization or partial depolarization, was proposed in this paper. The novel pulsed-power supply method was verified by experiments and the experimental result showed that the machining accuracy was significantly improved.