The phase field microelasticity approach to mesoscale modelling of mobile crystal defects is reviewed. Various defects are modelled in the same theoretical framework, including dislocations, cracks and free surfaces in single crystals, polycrystals and heteroepitaxial films. The model is also applicable to diffusional and displacive phase transformations. The phase field microelasticity model is based on Ginzburg-Landau phase transition theory with modification by incorporating the transformation micromechanics. It numerically solves the exact elasticity equation that governs the long-range elastic interactions of structural defects which determine the mechanical properties of materials. The mesoscale microstructures of arbitrary geometrical complexity are described by a set of structure density fields or phase fields, without explicitly tracking the moving boundaries. The topological changes during nucleation, annihilation, coalescence of defects and formation of various metastable configurations are automatically taken into consideration. No ad hoc assumptions on possible microstructure morphologies during evolution are required. Various nano- and mesoscale processes are simulated. The models enable one to investigate the structure-property relationships of complex material systems which are determined by the interplays between multiple physical processes.
展开▼
