An Atomistic Simulation of Special Tilt Boundaries in α-Ti: Structure, Energy, Point Defects, and Grain-Boundary Self-Diffusion

In hexagonal close-packed titanium, the symmetric tilt boundaries [2 (1) over bar(1) over bar0](01 (1) over bar3) and [2 (1) over bar(1) over bar0](02 (2) over bar1) have been studied by computer simulation using an embedded atom potential. The structure and energy of the boundaries under consideration have been calculated by method of molecular statics. The stability of the boundaries and grain-boundary self-diffusion coefficients have been calculated by molecular dynamics upon heating. It has been shown that the [2 (1) over bar(1) over bar0](01 (1) over bar3) boundary is stable up to the hcp -> bcc phase transformation temperature (1155 K), and the [2 (1) over bar(1) over bar0](02 (2) over bar1) boundary, up to 900 K. It has been shown that the grain-boundary diffusion coefficients are close to experimental ones.