Research On Constitutive Equations Of TA11 And Microstructure Simulation Of Blade

Blade plays a key role in energy conversion in aero-engine. In recent years, the studies of blade forming process have turned from the macro-plastic flow behavior to the microstructure simulation, mechanical property prediction, quality control and so on. The microstructure evolution of the metallic material determines the macro-mechanical properties of the blade to a large extent. Therefore, it is extremely important to control the mechanical properties of the product by understanding the microstructure evolution and its influencing factors of materials. The existing finite element simulation software does not have the function to simulate microstructure evolution. Therefore, it is necessary to embed the microstructure evolution model in user subroutines of DEFORM-3D software in order to simulation the microstructure evolution during hot forging process. The research works are summarized as follows.(1) Through the thermal simulation compression test of TA11 alloy, the stress-strain curves during the hot deformation have been obtained. And the flow behavior of high temperature has also analyzed. Based on flow behavior of high temperature, the constitutive equations of plastic deformation for TA11 alloy is established. The average error between the equation and experimental data of the model is smaller than 13.9%. The model can be used to describe the flow behavior of TA11 titanium alloy during the thermal processing.(2) Through the metallurgical technique, the effects of the deformation process parameters on the microstructure have been studied. The models of volume fraction of dynamic recrystallization and grain size of dynamic recrystallization during dual phase (α+β) plastic deformation process have been established based on microstructure evolution. Average grain size model of primaryαphase of TA11 titanium alloy is established. The average error between the equation and experimental data of the model is smaller than 14.9%. The model can be used to describe the law of microstructure evolution of TA11 titanium alloy during the thermal processing.(3) In order to have the function to predict and simulate microstructure during hot forging process of TA11 alloy, the microstructure evolution model have been embedded in user subroutines of DEFORM-3D software. And the reliability of the program is verified through the simulation of cylinder upsetting.(4) The microstructure simulation of TA11 precision forging process is carried out. The influences of the deformation speed, deformation temperature and height reduction on microstructure evolution are analyzed. The distributing rule of the microstructure evolution and optimization of parameters have been obtained during cogging, pre-forging and finish forging processes of the blade. The results are of great significance to select the technology parameters of the precision forging process of the blade.