Role of intersecting grain boundary on the deformation of twin-twin intersection

摘要

Using in situ nanomechanical testing under high-resolution transmission electron microscope, we reveal that the grain boundary at the twin-twin interaction region (referred to as GB(T)) can either migrate via a shuffling process to contribute to the dislocation transmission or facilitate the dislocation cross-slip between the two intersected twins. Stress condition, energy barrier and geometric structure of the GB(T) can influence these two modes of dislocation activities at the intersection region. Besides, the dislocations inside the incoming twin can traverse the GB(T) by dislocation-GB(T) reactions. These findings should have general implications to the understanding of the deformation of nanotwinned materials. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.