Abstract Scope |
This talk will be based on paper of “In situ atomistic observation of disconnection-mediated grain boundary migration” by Q. Zhu, J. Wang, J. Li, Z. Zhang, S. X. Mao, Nature Comm. 10, 156 (2019). Shear-coupled grain boundary (GB) migration plays a significance role in the deformation of nanocrystalline and polycrystalline materials, but the underlying migration mechanism at the atomic scale remains largely unclear. The migration of Σ11(113) coherent GBs in gold bicrystals was investigated by a state-of-art in situ shear testing technique at atomic level Results showed that the shear-activated GB migration could be mediated by the motion of GB disconnections, which was conducted through the frequent composition and decomposition of single-layer and double-layer disconnections. Furthermore, it is demonstrated that the triple GB junctions can be act as effective sites for the nucleation of disconnections. |