Self-diffusion in < 100 > symmetrical tilt grain boundaries in tungsten: Molecular dynamics simulation

Abstract

The structure and energy of grain boundaries, the energies of point defects formation in them and grain-boundary self-diffusion coefficients in 18 < 100 > symmetrical tilt grain boundaries in tungsten have been determined by atomistic simulation. The dependences of grain boundary energies, defect formation energies in them and activation energy of grain-boundary self-diffusion on the misorientation angle have been calculated. A structural phase transformation has been discovered in Σ5(310) and Σ5(210) boundaries, which affected the diffusion properties of these grain boundaries. The calculations performed are compared with the available experimental data on self-diffusion in grain boundaries of tungsten.