Modelling of microstructure formation and interface dynamics

A phase-field model for a general class of binary three-phase metallic alloys is presented which describes both, multi-phase solidification phenomena as well as polycrystalline grain structures. The model serves as a computational tool to simulate the motion and kinetics of multiple phase boundaries and enables the visualization of the diffusion processes and phase transitions in multi-phase alloy systems. A selection of numerical simulation results illustrates the capability of the phase-field model to recover a variety of complex experimental growth structures. In particular, the discretized model is used to simulate the microstructure evolution in eutectic, peritectic and monotectic alloys. Moreover, the temporal development of polycrystalline grain structures with effects such as wetting, grain growth, symmetry properties of adjacent triple junctions in thin film samples and stability criteria at multiple junctions is shown in various simulations.