Abstract Mechanical and fatigue performance of γ-γ′ Ni-base superalloys are strongly affected by the antiphase boundary energy (APBE) of the γ′ precipitates which, in turn, is dictated by the alloy's composition. Due to the multicomponent character of these alloys, establishing composition-APBE relationships are challenging, even though the qualitative effect of individual solutes on the APBE may be known. This work attempts to utilize density functional theory-based cluster expansion calculations to systematically assess the effect of composition on the APBE of the γ′ phases in Ni-base superalloys. We aim to elucidate the influence of not only one single element but also multiple coexisting alloying elements on the γ′ APBE. By explicit consideration of configurational disorder via Monte Carlo sampling, the effect of temperature on the APBE has also been analyzed. This work reveals that (1) effects of individual solute element M on the APBE energy obtained in an isolated, ternary condition (i.e. in Ni3-xAl1-yMx+y) does not directly translate to a multi-solute case and that (2) the mutual synergistic interactions among different solute elements are not negligible. Based on the present results, an empirical master equation that predicts the APBE based on the composition of the γ′ phases has been obtained.

中文翻译：

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合金元素对镍基高温合金γ'反相边界能的影响

摘要 γ-γ' 镍基高温合金的机械和疲劳性能受 γ' 析出物的反相边界能 (APBE) 的强烈影响，而反相边界能 (APBE) 又由合金的成分决定。由于这些合金的多组分特性，即使单个溶质对 APBE 的定性影响可能是已知的，建立成分-APBE 关系也具有挑战性。这项工作试图利用基于密度泛函理论的簇膨胀计算来系统地评估成分对 Ni 基高温合金中 γ' 相 APBE 的影响。我们旨在阐明不仅一种单一元素而且多种共存合金元素对 γ' APBE 的影响。通过蒙特卡罗采样明确考虑构型障碍，还分析了温度对 APBE 的影响。这项工作表明 (1) 单个溶质元素 M 对在孤立的三元条件下（即在 Ni3-xAl1-yMx+y 中）获得的 APBE 能量的影响不会直接转化为多溶质情况，并且 (2)不同溶质元素之间的相互协同作用不容忽视。基于目前的结果，已经获得了基于 γ' 相组成预测 APBE 的经验主方程。