title: Atomistic and continuums modeling of cluster migration and coagulation in precipitation reactions.
abstract: The influence of vacancy preference towards one of the constituents in a binary system on the formation of precipitates was investigated by atomistic and continuums modeling techniques. In case of vacancy preference towards the solute atoms, we find that the mobility of individual clusters as well as entire atom clusters is significantly altered compared to the case of vacancy preference towards the solvent atoms. The increased cluster mobility leads to pronounced cluster collisions, providing a precipitate growth and coarsening mechanism competitive to that of pure solute evaporation and adsorption considered in conventional diffusional growth and Ostwald ripening. A modification of a numerical Kampmann-Wagner type continuum model for precipitate growth is proposed, which incorporates the influence of both mechanisms. The prognoses of the modified model are validated against the growth laws obtained with lattice Monte Carlo simulations and a growth simulation considering solely the coalescence mechanism.
authors: Institut für Werkstoffwissenschaft und Werkstofftechnologie, Favoritenstr. 9-11, 1090 Wien, Austria.
authors: Piotr
authors: P
authors: Warczok
authors: Institut für Werkstoffwissenschaft und Werkstofftechnologie, Favoritenstr. 9-11, 1090 Wien, Austria.
authors: Jaroslav
authors: J
authors: Ženíšek
authors: Institut für Werkstoffwissenschaft und Werkstofftechnologie, Favoritenstr. 9-11, 1090 Wien, Austria.
authors: Ernst
authors: E
authors: Kozeschnik
keywords: Coalescence; Fe–Cu alloy; Growth kinetics; Monte Carlo simulation; Precipitation kinetics