Temperature dependencies of the relaxation, order and segregation at a tilt grain boundary in

Abstract

The thermal dependence of the relaxation, order and segregation in the vicinity of a = 5 (210) [001] tilt grain boundary in the Cu 3 Au L1 2 binary alloy is investigated by means of computer simulation with an empirical N-body potential. Energy minimization is performed in order to estimate the particularly strong relaxation effects in the vicinity of the boundary plane at 0 K. Monte Carlo simulations are carried out for constant chemical potential, number of particles, volume and temperature in order to study the thermal properties of the system. Detail is provided plane by plane, parallel to the boundary, which characterizes the temperature dependencies of the order, segregation, sublattice occupancy and relaxation. The vicinity of the boundary remains strongly affected by atomic relaxation and segregation at all temperatures, although no simple relation between relaxation and segregation is found. The evolution of longrange order and sublattice occupancy are strikingly different in the close vicinity of the boundary plane to those in the bulk. The boundary plane is fully disordered at all temperatures between 0.2 T c and 1.5 T c , where T c is the bulk temperature for the order-disorder phase transition. The transition to bulk properties with distance from the boundary is characterized quantitatively.The influence of the potential model is emphasized by means of a comparison between the results obtained with two somewhat different N-body potentials of similar nature.

An atomistic study of mechanical deformation of nanostructured Ni3Al synthesized by cluster compaction

“…This is the same potential as used in the study isolated Ni-Al and Cu-Au clusters and bulk alloys presented in Refs. [13,17,18]. The parameters suggested by Gao, Bacon and Ackland [19] were checked to allow an excellent prediction of the elastic constants of Ni 3 Al as well as of the cohesive energy and equilibrium lattice parameter of Ni 3 Al.…”

Structural and thermodynamic properties of elemental and bimetallic nanoclusters: an atomic scale study

“…Further assessment for other stoichiometries comes out the MC simulations presented in section 4 for bulk materials. The same potential form was successfully applied to study interface properties of Ni 3 Al [16,17] as well as order-disorder phase transitions in bulk Cu 3 Au [14,17], at various grain boundaries [18] as well as at surfaces [19].…”