ATOMISTIC SIMULATION OF SELF- DIFFUSION AND DIFFUSION Co ALONG SYMMETRIC TILT GRAIN BOUNDARIES [2¯1 ¯1 0] IN α-Ti

Abstract

The structure, point defects, self-diffusion, and diffusion of Co for four energetically preferred grain boundaries (GB) with the tilt axis [21 1 0] in α-Ti are being investigated by computer modeling methods. The structure and energies of the boundaries and the energies of the formation of point defects in GB, were calculated by molecular static modeling. The dependencies of point defect formation energies on the distance from the grain boundary plane are demonstrated. The coefficients of grain boundary self-diffusion are calculated by the method of molecular dynamics. The results of self-diffusion modeling are compared with the available experimental data. The simulation of grain boundary diffusion of the impurity Co in titanium is also performed. It is shown that the structure of GB affects the parameters of grain-boundary diffusion both in the case of self-diffusion and in the case of impurity diffusion, and the coefficients of grain-boundary diffusion may differ by several orders of magnitude depending on the structure.