Journal article
Ab initio investigations of the phase stability in tantalum carbides
Acta materialia, v 80, pp 341-349
01 Nov 2014
Abstract
Using a variable-composition ab initio evolutionary algorithm, the stability of various tantalum carbide compounds at ambient pressure and at 0 K was investigated. The results revealed that TaC, Ta6C5 and Ta2C are the lowest energy configurations, with Ta4C3 and Ta3C2 having slightly higher energies. The vacancy ordered Ta6C5 phase had three energetically degenerate structures. A competition between the vacancy ordered and stacking fault variation of the phases was seen, with the latter becoming more favorable with lower carbon content. The close formation enthalpy of each stable and metastable phase appears to "frustrate" the carbide in the co-precipitation of multiple phases for substoichiometric compositions. Density functional theory calculations also provided the elastic constants for each of the stable and metastable phases. As the carbon content increased, the elastic constant values increased. This was associated with the change in metallic to more covalent bonding of the carbide from the density of states. The collective results of this computational work provide insight into why specific tantalum carbide phases form and the consequences they have on microstructure and properties. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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Details
- Title
- Ab initio investigations of the phase stability in tantalum carbides
- Creators
- Xiao-Xiang Yu - University of AlabamaChristopher R. Weinberger - Drexel UniversityGregory B. Thompson - University of Alabama
- Publication Details
- Acta materialia, v 80, pp 341-349
- Publisher
- Elsevier
- Number of pages
- 9
- Grant note
- FA9550-12-1-0104 / Air Force Office of Scientific Research grant; United States Department of Defense; Air Force Office of Scientific Research (AFOSR)
- Resource Type
- Journal article
- Language
- English
- Web of Science ID
- WOS:000344208300030
- Scopus ID
- 2-s2.0-84906528377
- Other Identifier
- 991019350671504721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Materials Science, Multidisciplinary
- Metallurgy & Metallurgical Engineering