| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Formation of Three-phase Eutectic Grains on Primary Phases: Observations from in situ and Multi-modal Imaging |
| Author(s) |
George R. Lindemann, Paul Chao, Allen Hunter, Ashwin Shahani |
| On-Site Speaker (Planned) |
George R. Lindemann |
| Abstract Scope |
Primary phases within off-eutectic alloys are thought to impact the surrounding eutectic microstructure. Thus, a thorough understanding of eutectic nucleation and growth in the presence of primary phases is critical to predict microstructure and its properties. Here, we investigate eutectic solidification within an off-eutectic Al-Cu-Ag alloy through in situ synchrotron X-ray radiography. The eutectic front growth velocity was found to vary based on its proximity and orientation to a neighboring primary Al2Cu rod. Ex situ 3D focused ion beam tomography, paired with scanning electron microscopy and electron backscatter diffraction analysis, revealed the eutectic Al and Ag2Al “invades” the rod surface. In between the heterogeneously nucleated Ag2Al grains, protrusions of primary Al2Cu extend into the surrounding eutectic. We propose a competitive nucleation relationship between the Al and Ag2Al phases to explain this behavior as well as the diverse neighboring eutectic microstructures. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Solidification, Phase Transformations, |