About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Frontiers in Solidification X
|
| Presentation Title |
Atomic-Scale Insights into an Abnormal Columnar-to-Equiaxed Transition in Metal Additive Manufacturing |
| Author(s) |
Lin Gao, Tao Sun |
| On-Site Speaker (Planned) |
Lin Gao |
| Abstract Scope |
Producing refined microstructures has long been a central objective in modern metallurgy, including fusion-based metal additive manufacturing (AM). A recently observed abnormal columnar-to-equiaxed transition (CET) has sparked significant interest in the AM community, as it produces uniquely refined grains that cannot be explained by conventional CET criteria. This phenomenon is speculated to result from a solidification process mediated by liquid structural orderings, in which icosahedral short-range ordering is believed to significantly enhance the nucleation rate by acting as a primary template. To elucidate the underlying mechanisms of this abnormal CET, we conducted operando synchrotron X-ray total scattering experiments during AM processing, combined with rapid-acquisition pair distribution function analysis. This characterization captured the atomic structure of the melt pool and its evolution under various rapid solidification conditions. Our findings provide both mechanistic understanding and practical insight into leveraging this phenomenon as a novel strategy for microstructure control and refinement in AM. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Solidification, Additive Manufacturing, |