Research On Thermal Rotation Mechanism Of Aeroengine Sheet Metal Casing

With the development of aviation industry,sheet metal case,as the external load-bearing part of aeroengine,puts forward higher requirements for its reliability,production efficiency and service performance.As one of the parts of the aeroengine sheet metal case,the wall thickness gradient rotating parts are mostly made of titanium magnesium alloy and high temperature alloy.These materials have the disadvantages of high yield ratio,low elastic modulus,serious rebound,poor bending ability and poor stability in compression at room temperature.The hot power spinning technology can improve the molding of the hard to form materials at room temperature,improve their processing performance and reduce the cost Small spinning pressure,improve the surface quality and production efficiency of products.In order to effectively control the precise forming of tapered parts with gradual wall thickness,it is necessary to study the forming mechanism,the influence of process parameters on forming quality and its optimization.In this paper,high temperature alloy GH4169 tapered part with gradual wall thickness is taken as the research object,which is formed by hot spinning.Firstly,the sheet metal of Superalloy GH4169 is selected as the blank for finite element modeling,and the process of hot power spinning of Superalloy GH4169 tapered workpiece with gradual wall thickness is simulated by using deform finite element software.The distribution characteristics of equivalent stress and strain,temperature field and plastic flow of material are analyzed in the process of spinning Its forming mechanism.Secondly,using the method of single factor variable,this paper studies the influence of three process parameters on the forming quality of the spinning parts,which are the core die speed,the feed ratio of the spinning wheel and the temperature.Taking the straightness of the external surface of the cone,the roundness of the external surface of the cone,the difference of the overall wall thickness of the workpiece and the force parameters as the evaluation indexes,the law of the influence of process parameters on the forming quality of the workpiece is proved.Then,by using the orthogonal test scheme and the finite element simulation,taking the straightness error of the external surface of the cone and the standard deviation of the overall wall thickness of the workpiece as the evaluation index,the primary and secondary order of the influence of each process parameter on the forming quality of the workpiece is obtained,and the optimal process parameter combination of each evaluation index is obtained.Finally,the hot spinning experiment of GH4169 tapered part with gradual wall thickness is carried out.The reliability of the simulation results is verified by comparing the experimental results with the simulation results.The results of this paper provide a theoretical basis for the hot power spinning of sheet metal case of aeroengine.