Effects of the cathode dimension on the pit formation by scanning micro electrochemical flow cell (SMEFC)

Electrochemical machining (ECM) is a key technique for fabrication of structures on difficult-to-cut materials with high surface integrity. In this work, the prototype of the scanning micro electrochemical flow cell (SMEFC) is introduced and the working principle is explained. This process confines the electrolyte beneath the hollow electrode with the help of a vacuum insert. Unlike conventional ECM methods, SMEFC concentrates the electrolyte in a relatively small region, thus avoiding spreading phenomena. This present study focuses on the influence of cathode dimension on SMEFC machining performance. Three aspects are compared, including cross-sectional profiles of the machined pits and surface microstructures of the pits, as well as electrolyte droplet expansion during electrochemical dissolution. This comparison concludes that the smaller electrode contributes to higher localization. Furthermore, the instability in the case of the thinner electrode is described.status: publishe