About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Interstitial–Metal Interactions: The Outsized Role of Small Atoms
|
| Presentation Title |
Data-Driven Diffraction Libraries for Identifying Metastable States in Complex BCC Refractory Alloys |
| Author(s) |
Daniel A. Bolden, Israel Reimer, Louis Katz, Arda Genc, Ravit Silverstein |
| On-Site Speaker (Planned) |
Daniel A. Bolden |
| Abstract Scope |
Body-centered cubic (BCC) Refractory alloys exhibit exceptional high-temperature strength, but remain limited by their high ductile-to-brittle transition temperatures. Dilute interstitial additions have emerged as a promising strategy to improve mechanical performance by promoting metastable phase transformations. However, the transient crystallographic states remain difficult to resolve. We combine ML-enabled 4D-STEM with a Python-based diffraction engine that systematically maps the BCC-to-HCP Burgers transformation pathway by generating diffraction libraries for transient structures and all associated crystallographic variants (~12). The framework is applied to 4D-STEM datasets collected from Nb-rich Ti alloys containing ~1% interstitials across varying Nb concentrations. The analysis reveals that multiple metastable states follow the Burgers orientation relationship, demonstrates that forbidden reflections can lead to incorrect phase identification, and shows that in-plane lattice rotation quantitatively tracks transformation progress. This framework enables robust identification of metastable structures, providing the crystallographic foundation needed to understand and ultimately tailor the mechanical behavior of refractory alloys. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, High-Temperature Materials, Phase Transformations |