Improving surface processing quality in wire electrochemical micromachining by gas bubble chain

Abstract Wire electrochemical micromachining (WEMM) is a promising method to fabricate microstructures, but the gas bubbles generated make it more difficult to discharge electrolytic products out of the tiny machining gap, posing a significant challenge in the fabrication of microstructures using WEMM. Hence, gas bubbles are generally considered to be removed from the machining region as soon as possible. Herein, gas bubbles are taken advantaged of as a positive role to get rid of electrolytic products from the machining region. In this paper, the ethylene glycol solution is employed as electrolyte in WEMM to generate a gas bubble chain. Simulation and experiments were carried out to verify the feasibility of the method. It is demonstrated that the electrolytic products can be removed by gas bubble chains, which makes a significant contribution to the dramatic improvement of surface processing quality. The surface roughness achieved using the method is Ra = 0.032 μm on 3J21 alloy sheet and Ra = 0.025 μm on 304 stainless steel sheet. Complex microstructures with smooth surfaces are successfully fabricated.