Abstract
Solidification microstructures were predicted by developing a new coupling model which is based on the Cellular Automaton (CA) method for the micro scale and Direct Finite Difference (DFD) for heat transfer calculation. The developed CA-DFD model takes into account heterogeneous nucleation whose process is determined continuously according to the gaussian distribution for either surface or bulk liquid of castings with 3 nucleation parameters, respectively. After the CA-DFD model had been proved through the comparison of the predicted microstructure with that of real castings of Al-7 mass % Si, the newly developed CA-DFD model was used to identify the effects of these six parameters.
