Monte Carlo simulations of segregation at [001] twist boundaries in a Pt(Au) alloy-II. Discussion

A. Seki*, David N Seidman, Y. Oh, S. M. Foiles

*Corresponding author for this work

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Abstract

A three dimensional plot of the density of Au atoms versus the position coordinates for the (002) planes, immediately adjacent to the interface, for a θ = 5° [001] twist boundary, suggests the presence of a hill-and-valley structure in the Au segregation behavior at 850 K. The valleys correspond to the regions of good atomic fit between the regions of misfit; the hills correspond to the cores of the pairs of orthogonal primary grain boundary dislocations. A model for the Monte Carlo simulations is developed that leads to a linear expression for Saver containing a core segregation factor (Score). For this model Score has a single value for all twist boundaries at a given T. All the Monte Carlo results can be plotted on a single Arrhenius plot and the Gibbs free binding energy of a Au atom to the cores of the primary grain boundary dislocations extracted; the binding enthalpy and entropy of segregation are 0.095 ± 0.01 eV and κB (0.49 ± 0.10) respectively.

Original languageEnglish (US)
Pages (from-to)3179-3185
Number of pages7
JournalActa Metallurgica Et Materialia
Volume39
Issue number12
DOIs
StatePublished - Jan 1 1991

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ASJC Scopus subject areas

  • Engineering(all)

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