Abstract and subjects
Grain boundaries can play a significant role in the mechanical response of materials. Atomistic simulations are used to investigate 79 coincidence site lattice grain boundary structures and energies in tantalum, a model body-centered cubic transition metal. Quasi-symmetric Sigma 3, Sigma 5, Sigma 7, Sigma 13, and Sigma 27 boundaries are observed, of which Sigma 3 and Sigma 7 also exist as traditional mirror-symmetry conserving boundary structures. These results are supported by previous observations of similar phenomena in other bcc transition metal Sigma 5 boundaries. Metastable low energy Sigma 3 boundary structures in tantalum could influence the formation and stability of deformation twins and abnormal growth grain favoring Sigma 3 boundaries. (C) 2016 Elsevier Ltd. All rights reserved.