| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Local Chemical Ordering and Its Impact on Mechanical Behaviors, Radiation Damage, and Corrosion
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| Presentation Title |
The k-state effect in medium- and high-entropy alloys |
| Author(s) |
Angelo Andreoli, Andrea Fantin, Sergey Kasatikov, Vinícius Bacurau, Eric Mazzer, Michael Widom, Francisco Coury |
| On-Site Speaker (Planned) |
Angelo Andreoli |
| Abstract Scope |
The k-state effect is the term to describe the peculiar behavior observed in the specific heat capacity and thermal expansion of medium- and high entropy alloys. The CoCrFeNi alloy is selected for in-depth analysis; texturing, recrystallization, magnetic and second-phase transitions are excluded as possible causes of the K-state effect. Analyzing the electronic structure reveals the emergence of a pseudo-gap in the Density of States, implying a particular chemical affinity between the Ni and Cr atoms during alloying. Simulations combining Monte Carlo and Molecular Dynamics (MC/MD) reveal the existence of a significant amount of chemical short-range order. While experimentally detected by X-ray absorption spectroscopy, variations around Cr and Ni elements from those anticipated in a totally disordered structure are demonstrated. The bonding distances that have been measured correlate well with the MC/MD computations. A mechanism of order-disorder is proposed, which is then validated by the results of calorimetric studies. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Phase Transformations, Characterization |