About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Seeing is Believing -- Understanding Environmental Degradation and Mechanical Response Using Advanced Characterization Techniques: An SMD Symposium in Honor of Ian M. Robertson
|
Presentation Title |
Validated Theory-guided Design of Refractory Multi-principal-element Alloys with Oxidation-resistant Coatings |
Author(s) |
Duane D. Johnson, Prashant Singh, Andrey Smirnov, Gaoyuan Ouyang, Jun Cui, RanRan Su, John Perepezko, Matt Kramer |
On-Site Speaker (Planned) |
Duane D. Johnson |
Abstract Scope |
Refractory-based multiple-principal-elements alloys (MPEAs), with high-entropy alloys being a near-equiatomic subset, show great thermal stability and excellent high-temperature properties, except maybe oxidation resistance, and so some promise for replacing nickel-based superalloys as next-generation high-temperature materials. We showcase our theory-guided approach in down-selecting refractory MPEAs, and the effects of vacancies on phase selection and short-range order on strengthening. Using novel density-functional theory methods, we quantitatively predict key properties for arbitrary solid-solution alloys, e.g., structural, mechanical, stability, short-range order, and defect energies. Novel DFT-based predictions inform bulk combinatorial arc-melt synthesis and characterization, for verification and down-selection of superior mechanical properties and oxidation resistance. Then, for high-temperature applications and harsh environments, a protective, self-healing coating added to samples yield negligible mass change for (currently) 450+ hours at 1300oC. As “Seeing is Believing”, a few systems are highlighted both for theory-guided design and validation experiments. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Entropy Alloys, Computational Materials Science & Engineering, Environmental Effects |