Research On Electrolyte Jet Machining Of Micro Kerfs

Electrolyte Jet Machining (EJM) is a technology utilizing anodized electrolyte jet to impinge the processing zones. Grooves and kerfs with scale in0.1mm-1.0mm, suited to fabrication by EJM, are widely applied in aerospace, instrumentation, micro machinery and other domain. Based on micro-machining technology and research status of EJM, the micro-kerf machining experiments were conducted, the distribution of the flow field and electric field, as well as the influence of processing parameters on the grooves and kerfs forming quality were analyzed. The main researches are as follows:The theories and fundamental of the EJM and electrochemical machining were introduced. Membranous rapid flow condition on the work piece surface and hydraulic jump were proved through analyzing the jet flow state on the workpiece surface and the jet velocity at the exit. The jet velocity at the nozzle exit is consistent with the simulation. The maximum deviation is8.43%. The simulation of electro field in the processing zone shows that the current density on the work piece tallies with Gauss distribution.An EJM system was conducted, including motion control components, nozzle composed of precise quartz capillary and plexiglass cone convergent capillary chuck, cathode nozzle used for importing the electrolyte,20%NaNO3electrolyte, corrosion resistant high pressure diaphragm pump, the electrolyte circulation supply system composed of three grade filter nets, adjustable high voltage DC regulated power supply ranging from0～1000V. Dry tool setting devices with assisted electrode was designed. Polarization curve of EJM was measured, providing the EJM with experiment foundation.To acquire the forming laws of micro-grooves with EJM, the influences of jet angle, machining voltage, electrolyte pressure and other process parameters on the morphology of the groove were researched. The results show that the optimal jet angle is90°. The width and height of the grooves was proportional to the processing voltage. Width of grooves decreased with the increasing of electrolyte pressure. The depth of grooves first decreased and then increased with the increasing of the electrolyte pressure. Width and depth of grooves increased with the increasing of scan times, but the increase rate decreased. The optimal processing parameters are that processing voltage ranges from300V to550V, the electrolyte pressure is above0.3MPa. The current density distribution on the processing zone of EJM and the grooves section curves obtained in all parameters conform with the quadratic curve. The grooves section topography is mainly influenced by the current density. The micro-kerf machining experiments were conducted. The influence of scan times and processing voltage on topography of kerfs was analyzed. The result shows that pressure maintaining fixture can significantly improve the quality of obtained kerfs. Proper scan times can form kerfs with smooth morphology. Too many or too few scan times against the well formation of kerfs. The low processing voltage is beneficial for forming high quality kerfs. Smooth diamond grooves and free-form curving kerfs are obtained by using pressure maintaining fixture and optimal parameters.