About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
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High Entropy Alloys IX: Alloy Development and Properties
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Presentation Title |
Metastability and Phase Selection in High Entropy Alloys |
Author(s) |
Sebastian A. Kube, Pamela Banner, Sungwoo Sohn, David Uhl, Amit Datye, Suchismita Sarker, Apurva Mehta, Jan Schroers |
On-Site Speaker (Planned) |
Sebastian A. Kube |
Abstract Scope |
High Entropy Alloys (HEAs) span a vast composition space, across which single-phase solid solutions (SPSS) can form at varying degrees of metastability. We argue that metastable SPSS form through polymorphic solidification upon rapid cooling. To quantify a HEA’s metastability, we propose the critical cooling rate of SPSS formation RCSPSS, which is analogous to RCGlass for glass formation. On this unified basis, we compare multicomponent alloys by their metastability and tendency to form SPSS or glasses, which is determined by the underlying atomic dispersity. We explore large numbers of alloys in this space using combinatorial co-sputtering and high-throughput EDX and synchrotron XRD. Our new data set comprises ~10,000 ternary and quinary compositions based on 20 different elements. Amongst SPSS, we reveal a BCC preference effect: The BCC structure becomes increasingly favorable with increasing atomic size difference, because of its ability to accommodate atoms of various sizes more efficiently than FCC. |
Proceedings Inclusion? |
Planned: |