Micro wire electrochemical machining with an axial electrolyte flow

Abstract

Micro wire electrochemical machining is a useful technique to produce high-aspect-ratio slit micro-structures. To improve processing stability, the axial electrolyte flow is adopted to renew electrolytes in the machining gap. A wire electrochemical micro-machining system with an axial electrolyte flow unit is developed. A mathematical model of tool feed rate is presented. To investigate the influence of electrolyte flow on processing stability and machining efficiency, comparative experiments were carried out. The influence of applied voltage and electrolyte concentration on machining accuracy is studied and the parameters such as electrolyte flow rate and applied voltage are optimized. Low initial machining gap is applied to decrease the stray current machining in the initial machining period. With the optimal parameters, the high-aspect-ratio micro spline and curved flow channel with the slit width of 160 μm have been fabricated on 5-mm-thick stainless steel (0Cr18Ni9). The width of the slit is uniform and the aspect ratio is 31.

Reduction of stray corrosion by using iron coating in NaNO3 solution during electrochemical machining

“…The dissolution behavior of alloys also depends on its metal content. For example, Ni-20 % Cr-Co alloys show no passivation in NaNO 3 because of the effects of chromium [22]. This paper presents a new method for reducing stray current attack by using an iron coating on the surface of the workpiece in passivating NaNO 3 electrolyte solution.…”

Recent Advancements in EMM for Micro and Nanofabrication

“…To eradicate this problem, means other than the application of pulsed power supply are highly required. Therefore, researchers have introduced different means to enhance the mass transport phenomenon during the machining that involves traveling of wire electrode in one direction, application of microvibration of cathode wire, and renewal of electrolyte in the IEG by implementing axial flow [2].…”

Improving machining accuracy in wire electrochemical micromachining using a rotary helical electrode

“…Axial electrolyte flushing along the wire electrode was proven to be effective in enhancing the electrolyte refreshment [19]. Wang et al [20] pumped the electrolyte at a speed of 0.75 m s −1 and the electrode feed rate was improved to 0.5 μm s −1 . A microstructure in a 5-mm-thick stainless steel plate was fabricated with an interelectrode gap of 70 μm by using a tungsten wire electrode 20 μm in diameter.…”