Curvature driven grain boundary migration in aluminum: molecular dynamics simulations

Molecular dynamics simulations have been used to study steady-state. capillarity-driven grain boundary migration in three dimensions for a series of <111>-tilt boundaries in aluminium. The reduced boundary mobility and boundary enthalpy were determined as a function of misorientation and temperature. For the misorientations examined, the reduced mobility is a maximum and the activation energy for migration is a minimum at the Sigma7 misorientation. The reduced mobility is an Arrhenius function of temperature. Excellent agreement between the present three-dimensional simulation results. those obtained earlier in two dimensions and experiment is obtained for a wide variety of features. with the notable exception of the magnitude of the grain boundary mobility. The mobilities from the simulations are much higher than from experiment: the activation energies for migration tire much, lower. The present results are intrinsic, while the experimental measurements may be limited by extrinsic factors such as impurity drag. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.