Atomic-scale oxidation mechanism of high-entropy carbides via density functional theory and ab initio molecular dynamics

IF 3.5 3区材料科学 Q1 MATERIALS SCIENCE, CERAMICS

Journal of the American Ceramic Society Pub Date : 2025-02-22 DOI:10.1111/jace.20448

Yang Bai, Yuxin Liang, Juan Bi, Baoning Cui, Zhaopeng Lu, Huangxuan Wang, Xixi You, Bangsheng Li

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Abstract

High-entropy carbides (HECs) are increasingly recognized as promising materials for high-temperature applications, thanks to their remarkable mechanical properties and resistance to oxidation. This study investigates the initial oxidation mechanisms of HEC (Zr₀.₂₅Hf₀.₂₅Nb₀.₂₅Ta₀.₂₅)C through density functional theory and ab initio molecular dynamics simulations. Our results indicate that the (100) surface exhibits the highest stability, where oxygen molecules dissociate into atoms that preferentially adsorb at the threefold hollow site. Further analysis shows that oxygen atoms preferentially bond with Zr and Hf atoms, leading to the formation of oxides. The interaction between oxygen and the surface exhibits mixed ionic–covalent characteristics. Furthermore, oxygen atoms diffuse from the surface to subsurface octahedral sites via tetrahedral interstitial sites, with a migration barrier slightly above that of corresponding binary carbides. This research enhances our understanding of the oxidation resistance in HECs.

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基于密度泛函理论和从头算分子动力学的高熵碳化物原子尺度氧化机理研究

高熵碳化物（HECs）由于其卓越的机械性能和抗氧化性，越来越被认为是有前途的高温应用材料。本研究通过密度泛函理论和从头算分子动力学模拟研究了HEC （Zr 0 . 2₅Hf 0 . 2₅Nb 0 . 2₅Ta 0 . 2₅）C的初始氧化机理。我们的研究结果表明，（100）表面表现出最高的稳定性，在那里氧分子解离成优先吸附在三倍中空位置的原子。进一步分析表明，氧原子优先与Zr和Hf原子结合，形成氧化物。氧与表面的相互作用表现出混合离子共价特征。此外，氧原子通过四面体间隙位从表面扩散到亚表面的八面体位，其迁移势垒略高于相应的二元碳化物。本研究增强了我们对hec抗氧化性的认识。

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来源期刊

Journal of the American Ceramic Society 工程技术-材料科学：硅酸盐

CiteScore

7.50

自引率

7.70%

发文量

590

审稿时长

2.1 months

期刊介绍： The Journal of the American Ceramic Society contains records of original research that provide insight into or describe the science of ceramic and glass materials and composites based on ceramics and glasses. These papers include reports on discovery, characterization, and analysis of new inorganic, non-metallic materials; synthesis methods; phase relationships; processing approaches; microstructure-property relationships; and functionalities. Of great interest are works that support understanding founded on fundamental principles using experimental, theoretical, or computational methods or combinations of those approaches. All the published papers must be of enduring value and relevant to the science of ceramics and glasses or composites based on those materials. Papers on fundamental ceramic and glass science are welcome including those in the following areas: Enabling materials for grand challenges[...] Materials design, selection, synthesis and processing methods[...] Characterization of compositions, structures, defects, and properties along with new methods [...] Mechanisms, Theory, Modeling, and Simulation[...] JACerS accepts submissions of full-length Articles reporting original research, in-depth Feature Articles, Reviews of the state-of-the-art with compelling analysis, and Rapid Communications which are short papers with sufficient novelty or impact to justify swift publication.