The rich nature of the premelting transition of grain boundaries in solid solutions is analyzed. Part I of this paper uses a multi-phase field model, whereas Part II employs atomistic Monte Carlo simulations. To enable comparison, Cu-rich Cu-Ag solid solutions are chosen for study. In the phase-fiel
Thermodynamics of grain boundary premelting in alloys. II. Atomistic simulation
β Scribed by P.L. Williams; Y. Mishin
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 671 KB
- Volume
- 57
- Category
- Article
- ISSN
- 1359-6454
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β¦ Synopsis
We apply the semi-grand-canonical Monte Carlo method with an embedded-atom potential to study grain boundary (GB) premelting in Cu-rich Cu-Ag alloys. The R5 GB chosen for this study becomes increasingly disordered near the solidus line while its local chemical composition approaches the liquidus composition at the same temperature. This behavior indicates the formation of a thin layer of the liquid phase in the GB when the grain composition approaches the solidus. The thickness of the liquid layer remains finite and the GB can be overheated/oversaturated to metastable states slightly above the solidus. The premelting behavior found by the simulations is qualitatively consistent with the phase-field model of the same binary system presented in Part I of this work [Mishin Y, Boettinger WJ, Warren JA, McFadden GB. Acta Mater, in press]. Although this agreement is encouraging, we discuss several problems arising when atomistic simulations are compared with phase-field modeling.
π SIMILAR VOLUMES
The local density of states (LDOS) of electrons at grain boundaries of iron with or flout segregation ~h~ho~ or boron) was calculated. The grain boundary structures constructed by using empirical atomic pair potentials were used as the model systems. The hopping integrals were calculated by using th