Investigation on the electrochemical machining of micro groove using masked porous cathode

Abstract

Micro groove, as a typical surface texture, has played an important role in the development of many advanced fields. This paper introduced an electrochemical machining of micro groove using masked porous cathode. A porous metallic plate covered with a mask was prepared as the masked porous cathode. During machining, the masked porous cathode was covered on the workpiece, and the electrolyte could flow into the machining region through the porous structure in the cathode for machining. As the machining unit was closed, the distribution of electrical field was uniform on the machining surface, which could improve the machining accuracy. In addition, the masked porous mask had no damage during machining and could be reused, which improved the machining efficiency. With this method, multiphysics coupling model, including flow field model, electric current model, heat transfer model, reactant transport model, and moving mesh model, was built to investigate their influence on the machining process with different flow modes. The simulation and experiment results indicated that compared with other two flow modes, jet flow mode could provide a high electrolyte velocity in the machining region around the nozzle, and the mass transfer process was enhanced, which was helpful to improve the machining quality. The effect of pulse duty cycle was investigated, and the pulse duty cycle of 20% with the frequency of 2 kHz could further improve the mass transfer process and was preferred to generate micro groove with low standard deviation and roughness. In addition, with the applied voltage rising, the depth of micro groove increased, and increasing the nozzle reciprocating motion number could enhance the mass transfer process during machining, which further improved machining quality. Finally, with the optimized flow mode and machining parameters, a group of ten micro grooves were well generated by using a masked porous cathode with ten micro slits, and the width was about 330 μm with the depth of 45 μm.