Ca Method To Simulate The Grain Growth Process

Microstructure modeling has been carried out by using a cellular automata (CA) method coupled with macro heat transfer calculation. The stochastic nature of nucleation process as well as the deterministic of dendrite growth is considered to simulate the crystal growth. Continuous nucleation model is applied to describe heterogeneous nucleation in liquid metal. On the basis of the simplified grain shape, the physical model and mathematical model for the simplified dendrite shape were established. Dendrite tip growth kinetics is taken into account in the computing. In addition, the CA method is employed to describe the equiaxed grain growth in the under cooled melts and the node capturing during the further growth of a grain. According to the above model, the microstructure simulation scheme was developed to model the grain formation. Two-dimensional calculations were performed to simulate the evolution of equiaxed dendritic morphologies. A modified CA (MCA) model, which used a more similar shape to the actual dendrite to describe the growthgrain, was considered and studied, in which a shape function L(θ)to describe the dendrite shape contour.