About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Hume-Rothery Symposium: Interface Structure and Properties: Impact on Microstructure Evolution
|
| Presentation Title |
Direct Observation of Grain Rotation Driven by Shear-Coupled Grain Boundary Migration |
| Author(s) |
Xiaoqing Pan |
| On-Site Speaker (Planned) |
Xiaoqing Pan |
| Abstract Scope |
Near-rigid-body grain rotation frequently occurs during grain growth, recrystallization, and plastic deformation in nanocrystalline materials, but its underlying mechanisms remain unclear. Here, we present direct evidence that grain rotation in platinum thin films arises from disconnection motion along grain boundaries (GBs). Using advanced in situ four-dimensional scanning transmission electron microscopy (4D-STEM) at elevated temperatures, we statistically correlate grain rotation with GB migration. High-resolution temporal datasets and grain segmentation analyses highlight pervasive grain rotation strongly coupled to GB migration. Complementary atomic-resolution imaging demonstrates disconnection-driven shear-coupled GB migration, resulting in localized shear strain accumulation. Our findings identify shear-coupled GB migration via disconnection motion as the primary mechanism behind grain rotation, bridging atomic-scale mechanisms with statistical behavior. This enhanced understanding informs predictive modeling and engineering strategies for optimizing mechanical strength and thermal stability in polycrystalline materials. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Modeling and Simulation, Other |