Molecular dynamics simulations of deformation in nanocrystalline Al-Pb alloys

A modified embedded-atom method (MEAM) potential was developed and used for molecular dynamics (MD) straining simulations of Al-Pb alloys with a grain size of 10 nm and Pb content up to 3 at.%. Monte Carlo (MC) simulations done at 300 K indicated that all the Pb is segregated to the grain boundaries in these alloys. As the Pb content increases, partial dislocation nucleation at grain boundaries is suppressed, and the plastic strain is accommodated by mechanisms other than dislocation slip. The increasing Pb content was accompanied by a reduction in the yield and peak stress values.