In this study, tungsten was machined successfully with the neutral electrolyte NaNO3 aqueous solution and bipolar current because the nonconductive oxide layer on the surface, which interrupts the electrochemical dissolution process, was removed by the NaOH generated when the polarity of the tungsten is negative. However, the tool electrode was worn due to the bipolar current. Although the tool wear ratio was decreased when the platinum sheet was used as tool electrode than that with the stainless steel plate used as tool electrode, the platinum tool was also slightly worn. Hence, to avoid the influence of the tool wear, a new method, WECG (wire electrochemical grinding), for tungsten machining with neutral electrolyte and bipolar current is proposed, and the running brass wire is used as the tool electrode. Thereby, the problem of tool wear inevitable due to the bipolar current was eliminated because the running wire tool was used in this method.
Han, W., & Kunieda, M. (2018). Wire Electrochemical Grinding of Tungsten Micro-rod with Electrostatic Induction Feeding Method. In Procedia CIRP (Vol. 68, pp. 699–703). Elsevier B.V. https://doi.org/10.1016/j.procir.2017.12.140