Electrochemical micromachining of micro hole using micro drill with non-conductive mask on the machined surface

Abstract

Abstract The stray current corrosion brings negative effects on the machining quality and accuracy in electrochemical micromachining (EMM) of micro hole, limiting the industrial application of EMM. This paper proposes the electrochemical micromachining of micro hole using micro drill with non-conductive mask on the machined surface. In this method, non-conductive mask was coated on the workpiece surface first. Then, the mask was drilled precisely by micro drill to expose the workpiece surface, which was a mask through-hole. Thirdly, on the location of this mask through-hole, the same micro drill was used as a cathode electrode to fabricate micro hole through EMM. Lastly, the redundant mask was removed through a chemical method without damaging the original surface of workpiece. The simulation results show that the mask coated on the workpiece surface can reduce the stray current significantly, thereby decreasing the stray corrosion effectively. The cyanoacrylate was chosen as an ideal mask material because of its excellent properties, such as low cost, easy operation, etc. Through the above method, micro hole with high quality and accuracy was fabricated successfully, demonstrating that using micro drill with non-conductive mask coated on the workpiece surface can not only effectively protect the workpiece surface from corrosion, but also improve the machining quality and accuracy of micro hole in EMM.