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E. Kozeschnik, B. Sonderegger:
"Precipitate nucleation in highly supersaturated solid solutions";
Talk: EUROMAT 2017, THESSALONIKI; 2017-09-17 - 2017-09-22.

Solid-state precipitate nucleation is commonly described within the framework of classical nucleation theory. The assumptions underlying this theory are valid, however, only under conditions of low supersaturation because, in this case, the size of the critical nucleus is sufficiently large such that interface energy and chemical driving force are roughly independent of the nucleus size. In highly supersaturated solutions, the nucleus can become so small that these assumptions do not hold any more. In this presentation, a novel model describing the size-dependence of interface energy and driving force is introduced and the implications for nucleation of small precipitates is discussed. It is shown that the interface energy is only dependent on size, whereas the volume free energy is additionally depending on the enthalpy difference between precipitate and matrix. Some case studies complement the analysis.

Precipitate nucleation