Casting Solidification Process Of Microstructure Simulation

With the development of the China. Aluminium alloy Cast, owing to their excellent properties ,has gotten more and more applications. Recently the numerical simulation of solidification process has been used to predict the nucleation and growth of grains and the diffusion of solute atoms in the microstructure of aluminium alloy casting and to evaluate the mechanical properties of the products, which has become one of the hotest topics for foundry all over the world.A combined Deterministic method and Probabilitistic method on the basis of the theory of metal solidification have been successfully used to set up a two-dimensional methematics and physical model which includes the nucleation model and the growth kinetic model to simulate the microstructure of almuminium alloy casting. In this model ,the preferred growth dorection of dendritic grains and the change of columnar grain to exquiaxed grain(CET) have been considered and the macroscopic simulation was introduced into microstructure simulation. A unified micro-macro model has been used succesfully to simulation the microstructure of aluminium alloy casting and to caculate the tensile strength of certain zone with the aids of obtained relation of temperature-grade acceleration rate and tensile strength.Microsoft Visual C++ 6.0 has been used to set up this simulation system that works under Windows 2000. This system can be used to simulation the microstructure and to predict the mechanical properties of the aluminium alloy casting.The "T" shape aluminium alloy casting were selected to test the simulation model. In a series of experiments, the different alloy compositions of the casting and the different mould materials and the different pour temperature were seleced to produce some different casting, and their microstructure characters were observed and their hardnesses were measured. The experiments indicate that the simulation results were accord with the experiment results, which proved the validity of this software system as a useful tool to predict the microstructure properties of aluminium alloy casting.