About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
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Symposium
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High Entropy Alloys VIII
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Presentation Title |
On the Exceptional Mechanical Properties and Effect of Local Order in CrCoN-based High-entropy Alloys |
Author(s) |
Robert O. Ritchie, Andrew M. Minor, Mark Asta, Jun Ding, Ruopeng Zhang, Shiteng Zhou, Qin Yu |
On-Site Speaker (Planned) |
Robert O. Ritchie |
Abstract Scope |
CrCoNi-based medium/high-entropy alloys can display exceptional combinations of strength, ductility and toughness, properties which are further enhanced at cryogenic temperatures. In situ TEM observations identify a sequence of multiple deformation mechanisms, associated with their high friction stress yet low stacking-fault energy, that act synergistically to generate such damage-tolerance. We believe that many of these properties are influenced at the atomic level by the presence of local chemical ordering. Here we describe DFT-based Monte-Carlo simulations to show that variations in local chemical order have a profound effect on the stacking-fault and twin-boundary energies, the TRIP effect, and the formation energy of point defects, and ongoing experimental studies using energy-filtered TEM to confirm its existence and provide evidence of its significant effect on elastic/plastic deformation properties. These results present the possibility of “tuning order in disorder” for atomistic tailoring of multiple-principal-element alloys to achieve specifically desired macroscale mechanical performance. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume |