About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond III
|
Presentation Title |
Theory-guided Design of Refractory Alloys for Ultra-high-temperature Applications |
Author(s) |
Prashant Singh, Gaoyuan Ouyang, Matthew J Kramer, Jun Cui, Duane D Johnson |
On-Site Speaker (Planned) |
Prashant Singh |
Abstract Scope |
Refractory alloys are promising candidates to replace Ni-based superalloys for high-temperature applications, such as gas-turbine blades, due to their exceptional mechanical properties at high temperatures. We analyzed key alloy features in solid-solution phases, such as phase stability, oxidation, chemical ordering, and defects energies as well as mechanical strength and intrinsic ductility using machine-learning. Density-functional theory (DFT) methods were employed to analyze the role of lattice distortion, electronegativity, and defect concentration on mechanical behavior of ML predicted compositions. We show that ML combined with DFT is able to capture the key structure-property trends. We also discuss a novel theoretical approach to characterize ductility in bcc refractory alloys. Bulk combinatorial arc-melt synthesis and characterizations were performed for validation and down-selection of compositions with superior mechanical properties. This work seeks to bridge existing gaps in refractory multiple-principal element alloy development. |