GRAIN BOUNDARY SELF-DIFFUSION: INFLUENCE OF THE PLANE OF BOUNDARIES

10.25712/ASTU.1811-1416.2024.03.002

Abstract

The computer simulation methods have been applied to calculate grain boundary self-diffusion of asymmetric tilt grain boundaries with the misorientation axis [111]. The misorientation angle of asymmetrical boundaries corresponds to the misorientation angle of the special grain boundary S13(134). The calculations have been carried out with the use of the Morse pair potential and the Cleri-Rosato many-body potential. The structure of asymmetric boundaries can be described in the model of structural units – all boundaries contain structural elements characteristic of the special grain boundary S13(134). We calculated the coefficients of grain boundary diffusion and constructed Arrhenius dependencies, from which we determined the activation energies of diffusion. These dependencies have from two to three linear sections. We found that at high temperatures the grain boundary region amorphizes before the adjacent grains.This suggests that the boundaries melt at lower temperatures, which ranged from 0.91 to 0.97 melting temperatures.