About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
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Presentation Title |
In-situ TEM Observation on the Two Distinct Shear-coupled Migration Behaviors of One Mixed Grain Boundary |
Author(s) |
Zhengwu Fang, Scott Mao, Guofeng Wang |
On-Site Speaker (Planned) |
Zhengwu Fang |
Abstract Scope |
Shear-coupled GB migration has received extensive attention in the past decades. However, the atomistic mechanisms of the shear-coupled migration of general mixed tilt-twist grain boundary have remained largely elusive to date. Here, by employing the in-situ transmission electron microscopy study, we have observed two distinct migration behaviors during the shear-coupled migration of a ⟨001⟩{200}⁄⟨01 ̅1⟩{1 ̅11} mixed tilt-twist grain boundary (GB) in the Au nano bi-crystal. The underlying atomistic mechanism is attributed to the activation of GB disconnections carrying Burgers vectors with different magnitudes and opposite directions. Two different lattice correspondence transformation relations are identified, which are attributed to the structural similarity of these atomic planes. This work provides direct experimental evidence on GB disconnections mediating the shear-coupled migration of mixed tilt-twist GB migration, and the uncovered two novel lattice transformation relations may have some implications for the development of theoretical models to predict the shear-coupled migration of general GBs. |