Electrochemical Machining with Scanning Micro Electrochemical Flow Cell (SMEFC)

Electrochemical machining (ECM) is one of the key techniques for fabricating structures on difficult-to-cut materials. It has a potential in the domain of high-end manufacturing because there is no post-process heat affected layer or surface stress. This study attempted to utilize a scanning micro electrochemical flow cell (SMEFC) as a method of ECM, which can confine the electrolyte beneath a hollow electrode with the help of a suction head. This method is capable of concentrating the electrolyte on a relatively small region in a controllable way. Without electrolyte splashing, it enables a lower consumption of the electrolyte, an easier integration with other methods and better safety for the operators. An test rig with desirable repeatability has been proposed and the accompanying on-line monitoring system has also been presented. A multi-physics model has been developed to theoretically study the machining process in a SMEFC. The electric field, the flow field and the temperature during the electrochemical dissolution have been analyzed in details. Finally, experiments have been conducted to examine the effects of a series of parameters on the cavity formation process by SMEFC. The microstructures on the machined surface have also been compared and analyzed to reveal the heterogeneous phenomenon. The machining results have shown that the cavity shape and the localization derived via SMEFC can be modulated by several parameters.