Experimental Study Of Shape Tube Pluse Electrochemical Drilling Of Small Hole

With the continuous development of aircraft engine manufacturing technology,improving engine efficiency and thrust-weight ratio has become one of the important development directions of aircraft engines.At present,the turbine inlet temperature of aircraft engines exceeds 1800 K,while the strength of metal materials will decrease under ultra-high temperature which is one of the important factors of blade fracture.The application of film hole cooling technology effectively reduces the blade surface temperature.Electrochemical machining is a processing method for the material removal of the processed parts by the principle of metal anodic dissolution.The processing technology can effectively avoid the recast layer problem after laser processing and electrical discharge machining and electrochemical machining has a great potential in the field of small hole manufacturing.This subject analyzes the defects of the epoxy resin coating insulation layer method,and utilized the capillary tube to insulate the tube electrode.The insulation method of capillary tube can be effectively insulated to the electrode under the condition of voltage control below 16 V by testing.The influence of voltage,electrolyte concentration,duty cycle and power frequency on the hole diameter is analyzed by single factor experiment.The influence degree is analyzed by orthogonal experiment,and the hole size of 630?m was drilled by using the optimized technological parameter.Finally,the effects of three kinds of electrolytes on the processing depth,such as sodium chloride solution,sodium nitrate solution and sodium nitrate solution mixed with a little amount of sodium citrate,were analyzed by experiment.The experimental results showed that adding sodium citrate in sodium nitrate solution could improve the processing of the hole depth.Utilized the solution as electrolyte,the influence of the bare tip length,cathode feed speed,electrolyte pressure and duty cycle on the hole depth is analyzed by single factor experiment.By using the optimized parameters,a small hole with a diameter of 620?m and depth of 13 mm is processed.