Fabrication of microscale concave and grooves through mixed-gas electrochemical jet machining

This study explored the application of electrochemical jet machining (ECJM) with and without mixing a gas and an electrolyte for spraying a workpiece. Specifically, the study conducted experiments of electrochemical machining with and without gas mixture for producing microscale blind holes and grooves; the efficiency levels of the two machining processes were compared. Results showed that mixing the gas and electrolyte could improve the machining efficiency and reduce the area of electric conduction between the electrolyte and a workpiece. This enhanced the current density on the workpiece surface and thus improved the material removal rate. According to this hypothesis, under microscopic conditions, the current density of the liquid is concentrated within the local range because of the gas shielding effect; therefore, the unit current density is high. However, a low voltage results in insufficient current density and can generate stray corrosion on the material, thereby adversely affecting the machining characteristics and surface roughness. In groove ECJM, increasing the electrode feed rate could reduce the machining time per unit area and overcut on the side and machining depth. In addition, the surface roughness could be improved.