Document Type
Article
Publication Date
12-7-2020
Abstract
High entropy alloys (HEAs) are promising candidates for high-temperature structural material applications. Oxidation is a major factor that must be accounted for when designing such materials and it is thus important to study the oxidation behavior of HEAs to enable the optimum design of next generation materials. In this study, the thermodynamic behavior of interstitial oxygen in a Mo-Nb-Ta-W high entropy alloy was explored beyond the dilute limit. This was accomplished by sampling configurations of the HEA and HEA-oxygen systems from an isothermal–isobaric ensemble using a series of first-principle-based Monte Carlo simulations. It was found that the interstitial oxygen had comparable stability at tetrahedral (T) sites and octahedral (O) sites. The stability of the interstitial oxygen was correlated with the composition of the surrounding local metallic environment. The O-site interstitial oxygen was further found to arrange in ordered clusters and was associated with enhanced mechanical properties as demonstrated by an increase in the bulk modulus with increasing oxygen content. Finally, the solubility of the interstitial oxygen in the alloy was found to decrease with temperature.
Source Publication
Journal of Applied Physics
Recommended Citation
Samin, A. J. (2020). A computational investigation of the interstitial oxidation thermodynamics of a Mo-Nb-Ta-W high entropy alloy beyond the dilute regime. Journal of Applied Physics, 128(21), 215101. https://doi.org/10.1063/5.0028977
Comments
© 2020 Author(s), published under an exclusive license with American Institute of Physics.
AFIT Scholar, as the repository of the Air Force Institute of Technology, furnishes the published Version of Record for this article in accordance with the sharing poilcy of the publisher, AIP Publishing. A 12-month embargo was observed.
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics as cited below and may be found at the DOI link on this page.
Funding notes: This work was partially supported by allocations of computational resources from the Ohio Supercomputing Center (OSC) and from the DOD HPC systems. In addition, the author would like to acknowledge support from the Air Force Office of Scientific Research (AFOSR) AFIT Faculty Research Council (Grant No. FRC 20-519).