The kinetics of gallium penetration into aluminum grain boundaries - In situ TEM observations and atomistic models

The penetration behavior of gallium into aluminum grain boundaries was comp ared with Al grain boundary properties estimated from atomistic computer mo dels. Penetration speeds in individual grain boundaries were measured in si tu in the transmission electron microscope (TEM), and the observed Al grain boundaries were simulated using the embedded atom method (EAM). Penetratio n speeds were relatively slow in low angle grain boundaries and most low Si gma boundaries; however, for high Sigma boundaries, penetration speeds vari ed widely and were not correlated with rotation angle or coincidence site l attice (CSL) Sigma value. Atomistic computer models suggested that the pres ence of structural barriers in the grain boundary plane was an important fa ctor in determining penetration speeds. (C) 2000 Acta Metallurgica Inc. Pub lished by Elsevier Science Ltd AII rights reserved.