界面能各向异性对镍基高温合金中固态不稳定性的影响：一项多尺度研究
Influence of Interface Energy Anisotropy on the Solid-state Instability in Ni-based Superalloy: A Multiscale Study
AI总结：
该研究开发了将DFT计算的界面能各向异性纳入介观相场模拟的多尺度框架，揭示其可改变镍基高温合金析出相形貌演化并抑制不稳定性，为高温合金微观结构设计提供了新途径。
AI中文摘要：
镍基高温合金的微观结构稳定性关键取决于γ'析出相的形貌及其演化，这一过程由原子尺度的弹性各向异性和界面各向异性所控制。本文提出一种新颖的定量多尺度框架，首次将原子尺度计算得到的界面能各向异性直接纳入介观相场模拟，以阐明Ni-Al体系中的形貌选择与不稳定性。我们采用密度泛函理论（DFT）精确预测关键晶面上取向依赖的γ/γ'界面能，随后开发了严格的解析映射方法，将三维（3D）界面各向异性分布系统地简化为二维（2D）模拟平面。这一方法实现了DFT获取的各向异性参数向连续介质相场模型的定量传递，该模型同时考虑了弹性非均质性和本征应变。模拟结果表明，明确纳入基于DFT的界面能各向异性从根本上改变了析出相的形貌演化，有效抑制了原本由过饱和度和弹性效应引发的不稳定性及小平面化现象。该框架搭建了从原子尺度到介观尺度建模的桥梁，实现了对析出相形貌的预测性控制，并为理解镍基高温合金中弹性贡献与界面贡献的相互作用提供了新视角，该方法为通过第一性原理引导的多尺度模拟实现先进高温合金的定量微观结构设计铺平了道路。
英文摘要：
The microstructural stability of nickel-based superalloys critically depends on the morphology and evolution of $γ'$-precipitates, which is governed by elastic and interfacial anisotropies at the atomic scale. Here, we present a novel quantitative multiscale framework that, for the first time, directly incorporates atomistically computed interface energy anisotropy into mesoscale phase-field simulations to elucidate morphological selection and instability in the Ni--Al system. We employ density functional theory (DFT) to accurately predict the orientation-dependent $γ/γ'$ interface energies for key crystallographic planes. A rigorous analytic mapping is then developed to systematically reduce the three-dimensional (3D) interface anisotropy landscape to the two-dimensional (2D) simulation plane. This enables quantitative transfer of DFT-informed anisotropy parameters into a continuum phase-field model that also accounts for elastic inhomogeneity and eigenstrain. Our simulations demonstrate that the explicit inclusion of DFT-based interface energy anisotropy fundamentally alters precipitate morphological evolution, robustly suppressing instability and faceting phenomena otherwise promoted by supersaturation and elastic effects. The framework bridges atomic- to mesoscale modeling, enabling predictive control of precipitate shapes and providing new insights into the interplay of elastic and interfacial contributions in Ni-based superalloys. This approach paves the way for quantitative microstructural design in advanced high-temperature alloys via first-principles-guided multiscale simulation.
