An atomistic view of grain boundary diffusion

Abstract

This paper presents an overview of recent computer simulations of grain boundary (GB) diffusion focusing on atomistic understanding of diffusion mechanisms. At low temperatures when GB structure is ordered, diffusion is mediated by point defects inducing collective jumps of several atoms forming a chain. At high temperatures when GB structure becomes highly disordered, the diffusion process can be analyzed by statistical methods developed earlier for supercooled liquids and glasses. Previous atomistic simulations reported in the literature as well as the new simulations presented in this paper reveal a close similarity between diffusion mechanisms in GBs and in supercooled liquids. GB diffusion at high temperatures is dominated by collective displacements of atomic groups (clusters), many of which have one-dimensional geometries similar to strings. The recent progress in this field motivates future extensions of atomistic simulations to diffusion in alloy GBs, particularly in glass-forming systems.

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Cited by in corpus (4)

• Direct atomistic modeling of solute drag by moving grain boundaries
• Relationship between grain boundary segregation and grain boundary diffusion in Cu-Ag alloys
• Fluid flow inside slit-shaped nanopores: the role of surface morphology at the molecular scale
• The origin of strings and rings in the atomic dynamics of disordered systems