第一原则热力学研究TiO和TiNb二进制系统中的α相
Ning Zhang1, Alessandro Mottura1
1School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
The Journal of chemical physics
|May 20, 2024
概括
本研究使用第一原理计算和集群扩张来探索-氧 (Ti-O) 和- (Ti-Nb) 合金的热力学特性. 这些发现为了解这些高温材料的相位行为提供了强大的方法.
科学领域:
- 材料科学 材料科学 材料科学
- 计算材料科学科学 计算材料科学
- 热力学是一种热力学.
背景情况:
- 有氧 (O) 和 (Nb) 的 (Ti) 合金对于高温和耐腐蚀应用至关重要.
- 研究α Ti-O和Ti-Nb系统的热力学特性至关重要,但由于实验的复杂性而具有挑战性.
- 现有的实验技术和建模方案在准确地描述这些合金方面存在局限性.
研究的目的:
- 研究α Ti-O和α Ti-Nb系统的基本状态特征和热力学特性.
- 揭示原子结合相互作用和振动对相位过渡的影响.
- 建立一个可靠的计算方案来预测基于Ti的合金中的相位行为.
主要方法:
- 结合第一原则计算与集群扩展方法.
- 分析电子结构以了解原子结合.
- 应用了德拜-格鲁尼森模型和蒙特卡洛模拟来进行热力学属性分析.
- 研究了振动对Ti-O中的秩序-混乱过渡的影响.
主要成果:
- 在α Ti-O和α Ti-Nb系统中揭示了原子结合相互作用.
- 成功建模了α相的热力学特性,与Ti-Nb.的实验相极限达成良好一致.
- 量化了振动对Ti-O的秩序-混乱过渡温度的影响.
- 为Ti-O和Ti-Nb生成集群膨胀系数,对三元合金研究有用.
结论:
- 综合计算方法为研究α Ti-O和α Ti-Nb的热力学特性提供了一种有效的方法.
- 这些发现为研究Ti-Nb-O三元合金中的相位平衡提供了基础.
- 这项研究提出了一个可靠的方案,用于探索其他hcp Ti 基合金中的相位热力学.
相关概念视频
Phase Diagram
5.8K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
5.8K
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
1.8K
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
1.8K
Thermodynamic Potentials
823
Thermodynamic potentials are state functions that are extremely useful in analyzing a thermodynamic system. They have dimensions of energy. The four important thermodynamic potentials are internal energy, enthalpy, Helmholtz free energy, and Gibbs free energy. These thermodynamic potentials can be expressed using two of the following variables: pressure, volume, temperature, and entropy. These two variables are expressed as the rate of change of the thermodynamic potential with respect to other...
823
Bonding in Metals
47.2K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
47.2K
Metallic Solids
18.4K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.4K
Phase Transitions
19.1K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
19.1K


