Abstract In order to understand the role of chemical short-range order on deformation mechanisms in FCC compositionally complex alloys, a random model alloy (Co30-Fe16.67-Ni36.67-Ti16.67) is annealed at various temperatures using Hybrid Molecular-dynamics/Monte-Carlo simulations. The simulations produce significant chemical short-range order (CSRO) that increases with decreasing annealing temperature. Annealing tends to homogenize regions of high enthalpy due to: (1) chemical species redistributing into more compact configurations, and (2) pairs of atoms forming chemical bonds that lower the overall energy of the system; the composition explored here shows significant amount of ordering in Ti-Fe pairs with respect to random distributions as described by pairwise (EAM) potentials due to Johnson and Zhou. An energy topology approach is used to assess the local strengthening behavior in random solid solutions and annealed systems, where an interesting interplay is observed between misfit components and chemical short-range order affecting the overall critical resolved shear stress. The role of short-range order on the critical yield stress is quantified and compared with current solid solution models. Finally, we propose and validate an extension to the Labusch-Varvenne class of high-concentration solid-solution analytic models that incorporates the effects of chemical short range order.

中文翻译：

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FCC 高熵合金模型中的化学短程有序强化

摘要 为了了解化学短程有序对 FCC 成分复杂合金变形机制的作用，随机模型合金 (Co30-Fe16.67-Ni36.67-Ti16.67) 在不同温度下使用混合分子-动力学/蒙特卡罗模拟。模拟产生显着的化学短程有序 (CSRO)，其随着退火温度的降低而增加。退火倾向于使高焓区域均质化，原因是：(1) 化学物质重新分布成更紧凑的结构，以及 (2) 形成化学键的原子对，降低了系统的整体能量；此处探索的组成显示了 Ti-Fe 对中大量有序的随机分布，如 Johnson 和 Zhou 的成对 (EAM) 势所描述的那样。能量拓扑方法用于评估随机固溶体和退火系统中的局部强化行为，其中在不匹配的组件和影响整体临界解析剪应力的化学短程有序之间观察到有趣的相互作用。短程有序对临界屈服应力的作用被量化并与当前的固溶体模型进行比较。最后，我们提出并验证了对 Labusch-Varvenne 类高浓度固溶体分析模型的扩展，该模型结合了化学短程有序的影响。短程有序对临界屈服应力的作用被量化并与当前的固溶体模型进行比较。最后，我们提出并验证了对 Labusch-Varvenne 类高浓度固溶体分析模型的扩展，该模型结合了化学短程有序的影响。短程有序对临界屈服应力的作用被量化并与当前的固溶体模型进行比较。最后，我们提出并验证了对 Labusch-Varvenne 类高浓度固溶体分析模型的扩展，该模型结合了化学短程有序的影响。