Exploration of the sliding behavior of a Σ11 grain boundary with precipitates in Ni-Al system using molecular dynamics

Molecular dynamics (MD) was used to gain insights into grain boundary (GB) shear mechanisms in alloys that require GB mobility in a field of coherent precipitates. The area fraction of the Sigma 11 affected by the gamma' was systematically varied to explore how GB shear mechanisms change with increased number of precipitates. Without precipitates, local atomic shuffling accommodates the Sigma 11 GB shear; above an area-fraction threshold, GB shear required dislocation emission. In addition to precipitate area fraction, the transition in GB shear mechanisms may also depend on precipitate shape/size, temperature, and GB misorientation. These factors will be investigated in future work. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. This is an open access article under the CC BY license. (http://creativecommons.org/licenses/by/4.0/)