A diffuse-interface field model is proposed for describing diffusional processes in coherent systems with arbitrary microstructures and arbitrary spatial distribution of structural defects such as dislocations. It takes into account the effect of both the coherency elastic energy of a microstructure and the elastic coupling between the coherency strains and defect strains. In this model, any arbitrary spatial distribution of defects is described using the micromechanics concept of space-dependent `stress-free' or `eigen' strains. As examples, the solute segregation as well as the nucleation and diffusional growth of a coherent precipitate around an edge dislocation are considered. It is shown that coherent nucleation may become barrierless under the influence of the local elastic field of a dislocation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys