Symmetric tilt boundaries in body-centered cubic tantalum

SCRIPTA MATERIALIA

卷:116

Article

Hahn, Eric N.^1,2  Fensin, Saryu J.²  Germann, Timothy C.²  Meyers, Marc A.¹ 

[1] Univ Calif San Diego, La Jolla, CA 92093 USA

[2] Los Alamos Natl Lab, Los Alamos, NM 94550 USA

关键词: Coincidence lattice;    Grain boundary structure;    Grain boundary energy;    Molecular dynamics (MD);    Transition metals;   

DOI  :  10.1016/j.scriptamat.2016.01.038

来源: Elsevier

【 摘 要 】

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.

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