| Strength of nanostructured ferritic alloys depends on the dispersion of high number density of nano scale Y-Ti-O clusters. The presence of these nanoclusters not only gives high temperature creep strength but also helps in reducing radiation damage effects. The exact structure and composition of these nanoclusters are not known yet. We are studying the mechanism of formation of these nanoclusters using density functional theory and lattice kinetic Monte Carlo (LKMC) simulations. Y, Ti and O interactions and migration energies are carefully modeled from DFT calculations and are further used to study formation of Y-Ti-O nanoclusters in Fe matrix with supersaturation of vacancy. Some of the fast processes which were slowing down the progress in LKMC simulations are incorporated in an effective way so as to accelerate the LKMC simulations. This study includes calculation of diffusion coefficient of Y which is considered to be the smallest and also the rate determining . The effect of vacancy concentration, presence of Ti and excess O on the formation of nanoclusters are also being analyzed. |
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