About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
High Temperature Oxidation of Metals and Ceramics
|
Presentation Title |
A Computational Investigation of the Early Stages of Degradation of High Entropy Alloy Surfaces |
Author(s) |
Adib Samin, Tyler Dolezal |
On-Site Speaker (Planned) |
Adib Samin |
Abstract Scope |
The early stages of oxidation on the surface of Al10Nb15Ta5Ti30Zr40 were studied using Density Functional Theory and thermodynamic modeling. Surface slabs were generated from a bulk configuration sampled from equilibrium using a multicell Monte Carlo method for phase prediction. The oxygen adsorbed with a preference towards sites with Ti and Zr. The surface was highly reactive to oxygen, yielding a dominating oxygen coverage of two monolayers over the temperature range of 100 to 2600 K and oxygen pressure range of 10-30 to 105 bar. Inward oxygen diffusion at low coverage was preferred in regions rich with Zr but slowed with the addition of Ti and Al. Diffusion rates drastically reduced at 1 ML, especially in the region rich with Ti and Zr, where strong metal-oxygen bonds were reported. Our results indicated that a high content of Ti and Zr increased the reactivity of the HEA surface to oxygen. |