熔模铸造蜡模注射成形过程中蜡料粘度的高精度建模OA

In the investment precision casting of aerospace titanium alloy structural components,the dimensional accuracy of wax patterns determines the quality of castings.Numerical simulation is a key technology for optimizing wax pattern injection processing,and its accuracy highly depends on the parameters of the wax viscosity model.As a non-Newtonian fluid,the viscosity-shear rate-temperature relationship of wax can be accurately described by the Cross-WLF model.However,the database of Moldflow software lacks parameters for this model,and traditional fitting methods exist defects:the simple least squares method is prone to falling into local optima,while the Newton's method has high computational complexity and numerical instability.Therefore,taking Kc-4017b wax as the research object,a quasi-Newton method integrating automatic differentiation and SVD regularization has been proposed for the viscosity modelling.The verification was carried out through numerical simulation of mold filling processes of annular stepped wax patterns combined with actual injection forming tests.The results show that the coefficient of determination(R2)of the quasi-Newton method for fitting is 0.989,which is significantly higher than that of the least squares method(R2=0.901),and the residual distribution is more uniform;the Moldflow simulation results corresponding to its fitted parameters have a high degree of consistency with the displacement trend of the measured data obtained via blue light scanning,enabling accurate identification of the key regions of wax pattern deformation.This study solved the difficult problem of high-dimensional nonlinear parameter fitting for the wax Cross-WLF model,and provided reliable parameter support for the numerical simulation of injection forming process of wax patterns in titanium alloy investment casting and a theoretical foundation for the investment precision casting processes of titanium alloy structural components.