| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
High Entropy Materials: Concentrated Solid Solution, Intermetallics, Ceramics, Functional Materials and Beyond
|
| Presentation Title |
The Role of Large Static Displacements in Stabilizing BCC High Entropy Alloys |
| Author(s) |
German Samolyuk, Yuri Osetsky, Malcolm Stocks, James R. Morris |
| On-Site Speaker (Planned) |
James R. Morris |
| Abstract Scope |
We present a density functional theoretical exploration of phase stability and competing crystal structures in medium and high entropy alloys formed of group IV and V elements. We find that configurational disorder may determine the crystal structure, even at low temperatures where entropic considerations are minimal. The static displacements are much larger for the body centered cubic (BCC) phase than is seen in face centered cubic high entropy alloys, and these displacements help stabilize the BCC phase. In some cases average displacements approach 10% of the near-neighbor distance, close to the Lindemann criterion for melting. The large displacements mimic temperature-driven fluctuations that stabilize the BCC phase in Ti, Zr and Hf.
This work is supposed by the Department of Energy’s Office of Science, through the Energy Dissipation to Defect Evolution EFRC (GDS, YO and GMS), and through the Materials Science and Engineering Division (JRM). |