A coring structure in which δ (fcc) grains have Ga-rich cores with Ga-poor shells forms during the (bcc) to δ (fcc) phase transformations in Pu-Ga alloys. There are considerable differences between the diffusivities of Ga in and δ and a large and anisotropic stress field exists in the coring structure due to the large lattice mismatch between these two phases and strong elastic anisotropy. We developed a phase-field model for simulating the coring structure evolution in three dimensions, taking into account the inhomogeneities of both Ga diffusivity and elastic properties. It is shown that the elastic interactions among different oriented δ grains and diffusive Ga atoms affect Ga diffusion path, the coring structure, and the growth kinetics of the δ phase.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Computer Science Applications
- Computational Theory and Mathematics