The influence of twins on the mechanical properties of nc-Al

The presence of grown-in twins in nanocrystalline-Al is found to enhance plastic deformation via twin-migration in which partial dislocations, emitted at the intersection of the twin boundary and the GB, travel through the entire grain. For samples without grown-in twins. full dislocation activity is observed as the predominant slip mechanism. These results are discussed ill terms of generalised planar fault energy curves for the Al potential used in the present work. Simulations of 2D columnar nc networks are also performed to investigate the role of grain and grain-boundary-network dimension on the mechanical properties of nc systems. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.