Research On Forming Process Of Inserted Tube For Air Coolant On Aeroengine

The cooling air tube, as an important part of a thrust to weight ratio of aero gas turbine engine, mainly used for cooling engine vane and regulating the temperature in the blade cavity field, including the cooling air outflows along the axial direction of the tube and through the holes on the tube wall to blade cavity of thin-walled parts, the tube end flanging process has become the bottleneck of the parts' manufacturing. At present, foreign advanced aircraft engine manufacturing companies implement manufacturing technology confidentiality for the part. Therefore, to carry out the forming process research is of great significance.The paper is focused on the cooling air tube of an certain type of aero gas turbine engine, through the analysis of the forming process characteristics and the present manufacturing situation, the research contents and key technical problems of this paper were proposed on the base of comprehensive discussion of the problems encountered in the actual production and the existing techniques. First, the original blank of cooling air tube was optimized based on its characteristics, and researched on the pulsed laser welding process of 0.2mm thick Inconel 625 through the thin plate butt welding experiment, obtained the optimized welding process parameters, and on the basis of that finished the welding experiment of cooling air tube and got the qualified blanks which could be used for the final forming experiment. In addition, the flanging process was studied on the combination of FEM and experiments. First of all, analyzed the feasibility and the impact factors of the cooling air tube during the bulging and punching flanging forming process based on plastic mechanics method, then the bulging and punching flanging process were simulated with finite element analysis by abaqus, mainly researched on the material flow and deformation process of different parameters of the flanging process, got the effect law of the pressure, the expansion core, the axial feed rate to bulging flanging and tube billet height and friction coefficient to punching flanging forming, and a method to improve the wrinkling and fracture defects was proposed. Bulging and punching flanging experiments were carried out based on the above research. The experiment results showed that the bulging flanging method appeared wrinkle due to the low pressure, punching flanging got the qualified part under the oil lubrication condition, and the experiment results and finite element simulation results had high consistency, compared with bulging flanging method, the punching flanging method has advantages in simple mold, low and easy to operate.Through the above research, this paper has obtained the following results: put forward an optimization method of preforming blank based on the characteristics and requirement of forming of the cooling air tube; got the laser welding parameters for pre forming blank; got the qualified parts through punching flanging method instead of the traditional manual flanging method and provided a simple and easy method for the practical production. The conclusions got in this paper can provide reference for the actual production of the cooling air tube and lay a certain foundation for the subsequent further research.