Molecular-dynamics simulations were used to study grain-boundary migration as well as grain-boundary self-diffusion of low-angle and high-angle [001] planar twist grain boundaries in copper (tables 10 and 11). Elastic strain was imposed to drive the planar [001] twist grain boundaries. The temperature dependence of the grain boundary mobility was determined over a wide misorientation range. Additionally grain-boundary self-diffusion was studied for all investigated [001] planar twist grain boundaries. A comparison of the activation energies determined showed that grain-boundary migration and self-diffusion were distinctly different processes. The behavior of atoms during grain-boundary migration was analyzed for all studied grain boundaries. The analysis revealed that usually in absolute pure materials high-angle planar [001] twist grain boundaries moved by a collective shuffle mechanism while low-angle grain boundaries moved via a dislocation based mechanism. The obtained activation parameters were analyzed with respect to the compensation effect.

Comparative Study of Grain-Boundary Migration and Grain-Boundary Self-Diffusion of [001] Twist-Grain Boundaries in Copper by Atomistic Simulations. Schönfelder, B., Gottstein, G., Shvindlerman, L.S.: Acta Materialia, 2005, 53[6], 1597-609

Table 10

Migration activation energy of [001] Cu twist grain boundaries