About this Abstract |
Meeting |
2nd World Congress on High Entropy Alloys (HEA 2021)
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Symposium
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2nd World Congress on High Entropy Alloys (HEA 2021)
|
Presentation Title |
ON DEMAND: Efficient Prediction of the Yield Strength of BCC High Entropy Alloys |
Author(s) |
Francesco Maresca, William Curtin |
On-Site Speaker (Planned) |
Francesco Maresca |
Abstract Scope |
Body-centered-cubic (BCC) high entropy alloys of the (Al)-Cr-Hf-Mo-Nb-Ta-Ti-V-W-Zr family show exceptional high temperature strength. Mechanistic yet efficient computational guidance is needed to identify the most promising alloys within the immense compositional space. Here, we introduce a holistic, parameter-free strengthening theory of screw and edge dislocations in BCC alloys. In contrast with the screw-controlled pure BCC metals, in non-dilute BCC alloys both edge and screw dislocations are pinned due to strong local energy fluctuations. Both screw and edge dislocations assume wavy/kinked minimum-energy configurations where dislocation segments of characteristic length zetac are pinned at low-energy sites. Edge dislocation strengthening, that scales with misfit volumes and elastic moduli, occurs at all temperatures because of the large energy barriers associated to energy fluctuations in the random alloy. The edge theory is used to predict the high-temperature yield strength of ~10M alloys in the Al-Cr-Hf-Mo-Nb-Ta-Ti-V-W-Zr compositional space, providing guidance for manufacturing high-strength BCC HEAs. |
Proceedings Inclusion? |
Undecided |