Dislocation climb driven by lattice diffusion and core diffusion

Diffusion of material has a crucial influence on dislocation motion, particularly at elevated temperatures. It is generally believed that, in single crystal, lattice diffusion prevails when the temperature high and core dominates relatively low Due to complexity modeling coupling between diffusion, given physical problem often simplified into two extremes where only one regimes considered. However, quantitative definition conditions under which each mechanisms dominant still lacking. In present work, we employ variational principle for analysis microstructure evolution; demonstrated how finite element (FE) based can be developed from it, competition synergy naturally taken consideration. A climb model further by incorporating FE nodal three-dimensional dynamics framework, also considers glide cross-slip processes. systematic study coalescence prismatic loops (PDLs) various conducted proposed method; together with analytical solutions motion circular PDL controlled mechanism map constructed, provides useful guidance determining loop sizes, spacing, temperature. The results show practical coarsening process, fast short circuit local atomic rearrangement, so that it size or distance small, temperatures lower than 0.5Tm (Tm melting point material). While, temperatures, large large, becomes more efficient. findings indicate simultaneous consideration both necessary quantitatively understand evolution related processes, such as creep post-irradiation annealing.