Numerical Simulation of Solidification Microstructure and Effects of Phase-field Parameters on Grain Growth Morphologies

By a simple phase field model, a series of numerical simulations of solidification microstructure was performed to show a rich variety of dendritic patterns. At the same time, the relation between the morphology of grain growth and some parameters including the strength of anisotropy, dimensionless latent heat and the size of initial solid zone was studied. It is for the first time that patterns of grain growth were associated with the size of initial solid zone, which is an interesting issue. The possible reason for this may be that variation in the size of initial solid zone may bring about fluctuation of the interface energy, making the interface unstable. Due to the stunning development of the computer performance and numerical solution techniques, great progress has been made in numerical simulation of the solidification microstructure since the last three decades. Among a variety of numerical techniques used to simulate microstructure, the phase-field method is considered to be a viable computational tool, by which realistic patterns of grain growth can be freely obtained. The appeal of the phase-field method can be expressed in two aspects. Firstly, it gives a simple, elegant description that seems to embody a rich variety of realistic physical growth phenomena. Secondly, from the computational point of view, it is in essence simple to obtain solutions. This is because it is not necessary to distinguish between the dierent phases. During the past decades, a vari