Research Of Cooling Air Tube By Electrochemical Machining With Movable Mask

The cooling air tube is one of the important components and parts in the aeroengine,playing an important role in regulating the temperature field of the blade cavity.The generating components of cooling air tube belong to the sheet metal and group-holes structure,whose pores are arranged densely on the surface and different from each other in size.Also,the materials are difficult to process because of high-temperature alloy.All above lead to a not small challenge in processing cooling air tubes.The electrochemical machining with movable mask,based on the principles of electrochemical machining,using the mask which restricts the corrosion area,to produce on the workpiece patterns similar to the movable mask.Compared to the traditional through-mask electrochemical machining,the mask of electrochemical machining with movable mask can be reused,and be independent with the workpiece.Eliminating the needs for lithography and exposure process and improving the processing efficiency,the electrochemical machining with movable mask has unique advantages in the processing of sheet metal and group-holes structures.In this paper,based on the technology of electrochemical machining with movable mask,the problems existing in the processing of cooling air tube are studied.The specific research contents are as follows:?1?The mathematical model of the interaction of electrolyte conductivity,temperature rise and the bubbles is constructed.And the influence of the electrolyte flow rate on the hole diameter uniformity is studied by simulation and experiments.It is determined that the inlet velocity of the electrolyte for the processed cooling air tube is 5m/s,and the pressure is 0.4MPa.?2?In order to solve the problem that the holes on the surface of cooling air tube are arranged in irregular array,the simulation analysis of the cylindrical flow around the irregular array cylindrical supporting in the machining channel are carried out.Based on the simulation results and the patterns of the front and rear cooling air tube,the fixture for electrochemical machining with movable mask is designed.?3?The hole-formation process with different mask diameters by electrochemical machining with movable mask is studied.Based on the research results,0.2mm mask diameter is chosen to machine?0.5₀⁺?0.1? mm hole on the surface of cooling air tube,and 0.25mm mask diameter is chosen to machine?0.6₀⁺?0.1? mm hole on the surface of cooling air tube.?4?The electrochemical properties of the cooling air tube materials?GH3536 superalloy?are measured and analyzed,and the influence of electrical parameters on the processing quality of holes is studied.The processing parameters of cooling air tube are determined.Under this parameter,the qualified cooling air tubes are successfully processed.