Abstract This paper discusses the effect of stress on the solubility and diffusivity of vacancies using the elasticity theory of point defects. To support the discussion, results are compared with DFT calculations to verify model accuracy. The particular case of vacancies in aluminum is discussed in detail (DFT-elasticity), while three other metallic fcc systems – Ni, Cu and Pd – are discussed through the elasticity approach only. Different types of loading were considered: hydrostatic, multi-axial and shear stresses. In the case of a uni-axial loading, two different directions were investigated: the first along a main crystallographic direction, i.e. [001], and the second perpendicular to the dense plane (111). In order to quantify the effect of stress on diffusivity, the diffusion coefficient of each configuration was expressed for further calculations. By analyzing the symmetry break during the loading process, non-equivalent atomic jumps were identified and diffusion equations obtained. A multi-physic approach was carried out by combining first-principles calculations, to study atomic-scale processes, and a multi-state formalism, to obtain exact diffusion equations. Results show that elasticity accurately captures the effects of stress on vacancy diffusion and solubility and an application method is presented.

中文翻译：

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应力对 fcc 系统中空位形成和扩散的影响：DFT 计算与弹性理论之间的比较。

摘要 本文利用点缺陷的弹性理论讨论了应力对空位溶解度和扩散率的影响。为了支持讨论，将结果与 DFT 计算进行比较以验证模型的准确性。详细讨论了铝中空位的特殊情况（DFT 弹性），而其他三种金属 fcc 系统——Ni、Cu 和 Pd——仅通过弹性方法进行讨论。考虑了不同类型的载荷：流体静力、多轴和剪切应力。在单轴加载的情况下，研究了两个不同的方向：第一个方向沿主要晶体学方向，即 [001]，第二个方向垂直于致密平面 (111)。为了量化应力对扩散率的影响，表达了每种配置的扩散系数以供进一步计算。通过分析加载过程中的对称性破坏，确定了非等效原子跳跃并获得了扩散方程。通过结合第一性原理计算来研究原子尺度过程和多态形式化来获得精确的扩散方程，从而实现了一种多物理方法。结果表明，弹性准确地捕捉了应力对空位扩散和溶解度的影响，并提出了一种应用方法。以获得精确的扩散方程。结果表明，弹性准确地捕捉了应力对空位扩散和溶解度的影响，并提出了一种应用方法。以获得精确的扩散方程。结果表明，弹性准确地捕捉了应力对空位扩散和溶解度的影响，并提出了一种应用方法。