About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
|
Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond IV
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Presentation Title |
F-10: The Effect of W Concentration on the Thermodynamic Properties of MoNbTaW |
Author(s) |
Sarah E. O'Brien, Matthew J Beck |
On-Site Speaker (Planned) |
Sarah E. O'Brien |
Abstract Scope |
Multi-principal element alloys (MPEA) discourse has examined the influence of vibrational entropy (S<sub>vib</sub>), typically around the equatomic compositions. It is known that compositional variation plays a role in the S<sub>vib</sub>. Previous work explored the S<sub>vib</sub> for MoNbTaW based MPEAs (ex. Mo<sub>9</sub>Nb<sub>9</sub>Ta<sub>9</sub>W<sub>27</sub> and Mo<sub>10</sub>Nb<sub>10</sub>Ta<sub>10</sub>W<sub>24</sub>). In said work, the S<sub>vib</sub> at 1000 K, an easy point for comparison, was half that of the equatomic, but S<sub>vib</sub> shifted very little between the two compositions. The study quantifies the S<sub>vib</sub> of with respect to the concentration, specifically altering the W concentration. The work utilizes density functional theory (DFT) and density functional perturbation theory (DFPT) to simulate S<sub>vib</sub> and other thermodynamic properties. The S<sub>vib</sub> at 1000 K is more sensitive near the equatomic concentration and when the concentration of one element is near zero. It plateaus, however, for most of phase space. This further expands on high throughput studies by also comparing at higher temperatures. |