Research On Pressure-Regulating Precision Casting Of Floating Wall Tile For Aero Engine Combustion Chamber

As an important high-temperature and complex thin-walled component on the combustion chamber of an aero-engine,the key technology for accurate forming of M951 superalloy floating wall tile needs to be broken.The most commonly used molding process is precision casting,but due to the complex thin-walled structural characteristics of the floating wall,quality problems such as severe wax mold deformation,high resistance during the thin-wall filling process,and severe residual stress and deformation of the finished product often occur.Therefore,it is very important to carry out process exploration and optimization based on the various process links of precision casting.In this paper,the anti-gravity pressure-regulating precision casting process is used,and Moldflow software and ProCAST software are used to numerically simulate the injection molding process and floating wall tile casting process of M951 superalloy floating wall tile wax mold.The simulation prediction and experimental verification have laid the foundation for the engineering application and equipment development of pressureregulating precision casting of superalloy.The main work of this paper is as follows:(1)Through the test of the thermal conductivity,viscosity,and compressibility of the melt of the wax material,it can provide reliable hot material performance data for the floating wall tile wax mold.Basing on Moldflow software,the simulation of the filling + holding pressure +warping process of the wax mold was performed.The effects of different gate positions and holding pressure on the filling and deformation of the wax mold were discussed to optimize the molding process of it.(2)By using the temperature field,flow field and microstructure module of ProCAST software,the simulation and filling and solidification process of gravity casting and pressure-regulating precision casting of M951 superalloy floating wall tile were realized.By comparing the filling ability of M951 superalloy melt,the casting defects and grain size of different casting methods,it provides theoretical support for the selection of pressureregulating precision casting as the casting process for floating wall tiles.(3)The thermo-elastic-plastic constitutive model of M951 superalloy was established by phase diagram calculation and other means,and the actual pressure-regulating casting process was simplified.Using the stress analysis module of ProCAST,the effects of pouring temperature,mold shell heat transfer status,filling pressure rate,and solidification pressure on the residual stress and deformation of floating wall tile castings were analyzed.It provides theoretical guidance through simulation for the implementation of pressure-regulating precision casting process for floating wall tiles.(4)A multi-component superimposed Kurz-Giovanada-Trivedi model on kinetics of dendrite growth of M951 superalloy was established,and the effects of volume nucleation parameters and solidification pressure on the solidification structure of M951 superalloy ingot were analyzed using the CAFE module of ProCAST.The accuracy of the model was verified by pressure solidification experiments and macroscopic corrosion and metallographic observation,which laid the foundation for establishing a predictive model of the correlation between the microstructure and macroscopic mechanical properties of M951 superalloy.