Research On Techniques Of Electrolyte Periodic Commutation By Electrochemical Machining With Mask Of Group Holes

Group hole structure components are often arranged in a certain regularity of dense hole layout to achieve a certain function,in many industries have an urgent need,the structure has thin wall,porous,small spacing layout,material difficult to process and other characteristics.Therefore,it has higher requirements on machining accuracy and surface quality and it is difficult to form.Due to the advantages of high material removal rate,good surface integrity and low cost and high efficiency,electrochemical machining with movable mask has been applied to machining group holes.However,it is difficult to remove the electrolytic products and heat from the machining area with small gaps,which results in stray corrosion of the workpiece in the machining area and then reduces the machining quality.In addition to being the electrochemical reaction medium,electrolyte also plays the role of updating the electrolyte products and cooling heat in the machining gap to reduce the thermal impact,and the improvement of the flow field in the machining area will be conducive to improving the ability of concentrated etching and removal in the machining process.Therefore,this paper developed the technique of Electrolyte Periodic Commutation by Electrochemical machining with movable mask to improve the uniformity and accuracy of the machining area,through the repeated exchange of electrolyte flow direction in a certain period,the transport of electrolyte and the elimination of electrolyte products are promoted.The main research contents are as follows:(1)Establish the "PLC-Relay-Solenoid valve"Electrolyte Periodic Commutation control system.The system realizes electrolyte commutation through the on-off of the solenoid valve at the liquid inlet and outlet.Based on the signal transmission of the electromagnetic relay by PLC,the solenoid valve is controlled to realize automatic periodic commutation.(2)Electric field and flow field models were established based on anodic shielded Electrochemical machining with movable mask.Considering turbulence,temperature rise and other factors,the minimum flow rate of electrolyte was determined to be 14.1m/s and the inlet pressure was0.38MPa.The flow field simulation confirmed that good results could be obtained when the flow rate of electrolyte was 15m/s.(3)Designed and produced a special fixture for Electrolyte Periodic Commutation by Electrochemical machining with movable mask.The fixture,as the cathode,is made of metal materials.The left and right sides of the fixture are arranged symmetrically.(4)Conducted electrical tests on TC4 materials,studied the various parameters on the quality of the electrochemical machining of holes,the research shows that:when the electrical parameters of processing voltage U is 30v,the processing time t for the 165s,electrolyte commutating period T_c for5s,and electrolyte inlet pressure P is 0.4MPa,the hole has the suitable size and uniform aperture,lower roundness error and smaller taper,holes are of good quality and the processing effect is ideal.(5)The above parameters as the experiment parameters to carry out the optimization parameters of hole processing,processing out of the hole on the morphology of no obvious taper,the edge is rounded,not present gouges where whole pieces were missing and incomplete injury,measured,uniform pore diameter,roundness error smaller,on average,improve a roundness and taper hole smooth wall significantly lower.The quality of hole machining is high and the effect is expected.