Atomistic modeling of the segregation of lead impurities to a grain boundary in an aluminum bicrystalline solid

Using Monte Carlo simulations, new insights into the atomic segregation of lead (Pb) impurities to a Σ5 〈1 0 0〉 {2 1 0} tilt aluminum (Al) grain boundary have been obtained. Interatomic interactions in the Al-Pb alloy system were described using a modified embedded atom method potential with parameters that fit to the results of density functional calculations. The simulations predict segregation of Pb impurities along the Al grain boundary prior to the formation of Pb clusters. Analyses of grain boundary energies for varying concentrations of Pb suggests that grain boundaries in Al can be thermodynamically stabilized by Pb impurities with respect to a dilute solid solution of Pb in Al.