About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
| Presentation Title |
Grain Boundary Migration in the Presence of Singular Boundaries |
| Author(s) |
Gregory S. Rohrer |
| On-Site Speaker (Planned) |
Gregory S. Rohrer |
| Abstract Scope |
Recent studies of grain growth in polycrystals by 3D high energy X-ray diffraction microscopy have shown that grain boundary (GB) curvature is not a good predictor of the direction or speed of GB migration. Here, the influence of GB energy anisotropy on the driving force is considered. When there is a cusp in the energy as a function of orientation, some GBs will adopt a singular orientation. In this case, the Herring equilibrium condition becomes an inequality and the dihedral angle of the GB can take a range of values, leading to the flattening even non-singular boundaries. To describe the driving force for the migration of flat boundaries, the so-called weighted mean curvature driving force is formulated for a polycrystalline network. Simulated migration under this driving force can lead to unexpected behavior that contradicts conventional grain growth theory but is consistent with some experimental observations. |