材料科学
热力学
相图
灰烬
热膨胀
热容
尖晶石
纯物质热力学数据库
合金
化学稳定性
热力学过程
晶格常数
材料性能
格子(音乐)
固溶体
相(物质)
冶金
化学
衍射
物理
有机化学
光学
声学
复合材料
作者
Hongling Zhou,Yanzhou Ji,Yi Wang,Keqin Feng,Baifeng Luan,Xueyou Zhang,Long‐Qing Chen
出处
期刊:Acta Materialia
[Elsevier]
日期:2024-01-01
卷期号:263: 119513-119513
被引量:2
标识
DOI:10.1016/j.actamat.2023.119513
摘要
γ-Al2O3 is a commonly observed high temperature alumina phase during Al-based alloy oxidation. Due to the partially ordered, defective nature of the spinel structure arising from the partial occupancy in the Al sites, first-principles prediction of the thermodynamic properties of γ-Al2O3 has been challenging. In this work, employing the first-principles quasiharmonic approach, we obtain the finite temperature thermodynamic properties of γ-Al2O3, including entropy, chemical potential, heat capacity, thermal expansion coefficient, and elastic constants and the results are compared with those calculated for the other three alumina phases, i.e., α-Al2O3, θ-Al2O3, and κ-Al2O3. The calculated lattice constants and the predicted relative phase stability under 0 K and 0 GPa, α>κ>θ>γ, are consistent with experimental values and existing calculations, respectively. Based on the results, we constructed the temperature-pressure phase diagram covering the four Al2O3 phases (α, κ, θ, γ), which could provide for experimentally synthesizing the different alumina phases.
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