Diffuse-interface modeling of composition evolution in the presence of structural defects

A diffuse-interface phase field model is described for modeling the interactions between compositional inhomogeneities and structural defects. The spatial distribution of these structural defects is described by the space-dependent eigenstrains. It takes into account the effect of the coherency elastic energy of a compositional inhomogeneity, and the elastic coupling between the coherency strains and defect strains. The temporal evolution of composition is described by the Cahn–Hilliard equation. Particularly, the solute segregation, and nucleation and growth around dislocation slip bands and crack-like condensed interstitial dislocation loops are discussed. The effect of nucleated coherent precipitates on the stress field around these defects is analyzed