Monte Carlo simulations of segregation at [001] twist in a Pt(Au) alloy-1

This paper reports on Monte Carlo simulations utilizing embedded atom method (EAM) potentials which are used to study segregation of Au atoms-T = 850 to 1900 K - to [001] twist boundaries in a Pt-1.0 at.% Au bicrystal containing ∼ 5000 atoms. The twist angle (θ) ranges from 0 to 45 degrees. The average segregation factor (Saver), defined as a ratio of the Au concentration in the two (002) planes which adjoin the interface over the bulk value, increases linearly as θincreases to ∼35 degrees; Saver is ∼(1.2-3/5). No evidence is found for a systematic relationship between Saver and the Σvalue. The relationship between Saver and θis a result of the Au atoms segregating primarily substitutionally to the cores of pairs of orthogonal primary grain boundary dislocations (Part II)