Calculation of diffusion properties of grain boundaries in nanocrystalline copper

Abstract

We perform a molecular dynamics simulation of diffusion processes in the vicinity of the grain boundary. Calculations are carried out for the symmetric tilt boundary Σ = 5 at elevated temperatures. It is shown that in the vicinity of the grain boundary region high-temperature heating causes noticeable atomic displacements and thus governs active grain boundary diffusion. The calculation results demonstrate that the grain boundary diffusion parameters can be estimated with a rather high accuracy on the basis of molecular dynamics calculations. This gives an opportunity to study the atomic mechanisms of how temperature and external mechanical fields influence diffusion processes and structural rearrangement both in the vicinity of the grain boundary and within the grain bulk.