About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Local Chemical Ordering and Its Impact on Mechanical Behaviors, Radiation Damage, and Corrosion
|
| Presentation Title |
From Short-Range to Long-Range Ordering: Unraveling Local Chemical Ordering Evolution in (CrCoNi)93Al4Ti2Nb MEA via Advanced 4D-STEM Diffuse Scattering Analysis |
| Author(s) |
Po-Cheng Kung, Rui Feng, Peter Liaw, Jian-Min Zuo, Jessica Krogstad |
| On-Site Speaker (Planned) |
Po-Cheng Kung |
| Abstract Scope |
Local chemical ordering (LCO) in compositionally complex alloys is crucial for tuning material performance, yet quantifying its evolution remains experimentally challenging. We address this gap using advanced four-dimensional scanning transmission electron microscopy (4D-STEM) diffuse-scattering fluctuation and correlation (FluCor) analysis to probe the thermal evolution of LCO in a (CrCoNi)93Al4Ti2Nb medium-entropy alloy, which exhibits nanoscale short-range ordering domains with directional ordering after solution treatment. Our analysis reveals two distinct stages of local ordering: an early stage where directionality persists while ordering intensifies, forming strong directionally ordered domains; and an advanced stage where LCO domains extend ordering to equivalent crystal directions, transitioning to thermodynamically stable long-range ordering with full L12 symmetry. This work resolves the complex kinetics of LCO transformation and establishes 4D-STEM FluCor analysis as a critical tool for its unique capacity to extract directional data from individual nanoscale ordered domains, advancing fundamental understanding of early ordering phenomena. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, High-Entropy Alloys, |