Finishing of Micro-EDMed Surface based on Scanning Micro Electrochemical Flow Cell

A scanning micro electrochemical flow cell (SMEFC) has been developed to post-process the surface produced by micro-electrical discharge machining (EDM). The working principle of this compact SMEFC system built in-house is explained in details. Preliminary experiments show that a good handling and control of the electrolyte in a small region can be realized by this SMEFC, which avoids submerging the whole workpiece electrode in the electrolyte. In order to investigate the interrelation between the EDM traces and the finishing performance, experiments of line scanning with direct current and pulse current have been conducted on the micro-EDMed surfaces produced on a SARIX (R) SX-100 machine. The effects of the current density and feed rate on the finishing performance have also been analysed. Experiments have demonstrated that the recast layers and defects can be removed selectively, resulting in a better surface roughness. It is also proved that this finishing technique is feasible for post-processing discrete small regions of interest. (C) 2016 The Authors. Published by Elsevier B.V.