Forming Quality Of Cae Simulation, Based On The Ca-fe Method Superalloy Castings

Foundry production is an important part of the machine manufacture. The amount of casting occupies very high Proportion in the total amount of machine equipments. To get perfect castings the mechanism and the control technique of the microstructure of castings must be studied. The control of the grain structure is of primary importance in many solidification processes of castings, because the grain structure has influence on their mechanical properties and operating performances. The computer simulation method that is rising recently has been paid more and more attention because it can counteract the experiment-based method's weaknesses.In this thesis, the physics elements of the CAE simulation of the casting solidification have been discussed. Furthermore, the nucleation model, the growth kinetics model of the dendritic tip and the pervasion model of solute for the microstructure simulation have been discussed. Besides, the method of simulating the temperature field, the model coupling the simulation of macroscopic and microscopic view and the method combining the deterministic modeling and the stochastic modeling have been discussed. Based on the CA-FE method, the CAE simulation of the solidification has been done for superalloy K4169 cylinder ingots and aeroengine superalloy K4169 castings. The solidification temperature field and the grain structure features and the microstructure have been get by coupling the simulation of macroscopic and microscopic view and combining the deterministic modeling and the stochastic modeling.Using FDM method, the temperature variety on a cross section of superalloy K4169 cylinder ingots has been simulated and the temperature variety curve has been displayed. Using the finite element analysis software ANSYS, the temperature field of superalloy K4169 cylinder ingots has been simulated and the temperature variety curves of random three points on the section have been displayed. We can see that the three curves nearly superpose and agree well with the calculated results by the FDM method. And the simulated results agree well with the measured ones. These results show that the two methods are correct and attest that the assumption that the temperature on the section of superalloy K4169 cylinder ingots is homogeneity. Then, Using the fraction of solid, the simulation of temperature fields, the nucleation model and growth kinetics model of the dendritic tip were coupled to calculate grain structure features of superalloy K4169 cylinder ingots. The calculated results agree well with the measured ones. Based on a two-dimensional Cellular Automaton technique and the grain structure features of superalloy K4169 cylinder ingots, the microstructure of the studied section has been achieved by combining the deterministic modeling and the stochastic modeling. The simulated results agree well with experimental observation. Using FEM method, the temperature field of aeroengine superalloy K4169 castings has been simulated by the software ANSYS and the temperature variety curves of the studied section have been displayed. Then, the macroscopic and microscopic models were coupled to calculate grain structure features of aeroengine superalloy K4169 castings. The calculated results agree wellwith the measured ones. Based on a two-dimensional Cellular Automaton technique and the grain structure features of aeroengine superalloy K4169 castings, the microstructure of the studied section has been achieved by combining the deterministic modeling and the stochastic modeling. The simulated results agree well with the actual metallographic photographs.