Grain boundary segregation in Ni-base alloys: A combined atom probe tomography and first principles study
Grain boundary segregation in Ni-base alloys: A combined atom probe tomography and first principles study
复制标题
DOI：
10.1016/j.actamat.2021.117354
复制
发表时间：
2021-10-07
期刊：
影响因子：
9.4
通讯作者：
Razumovskiy, Vsevolod, I
中科院分区：
文献类型：
--
作者：
Ebner, Anna Sophie;Jakob, Severin;Razumovskiy, Vsevolod, I
晶界工程（GBE）在设计具有增强力学性能的新型多晶材料中具有重要作用。这种方法已被证明在镍基合金的设计中非常有效，其中晶界偏析有望在定义其力学行为方面发挥核心作用。在本研究中，我们采用先进的实验和理论相结合的方法，在原子水平上揭示了725镍基合金的晶界化学。研究方法包括原子探针层析成像（APT）测量和密度泛函理论（DFT）计算。我们还提出了一种方法，在基于DFT的模型方法中交叉验证DFT和APT结果，以评估界面过剩作为材料热处理历史及其化学的函数。采用理论和实验相结合的方法对725合金的三种改性的GB化学进行了详细的分析，并对研究结果进行了详细的讨论。(c) 2021作者。由Elsevier Ltd代表Acta Materialia Inc出版。这是一篇基于CC BY-NC-ND许可的开放获取文章（http://creativecommons.org/licenses/by-nc-nd/4.0/）
Grain boundary engineering (GBE) plays an important role in the design of new polycrystalline materi-als with enhanced mechanical properties. This approach has been shown to be very effective in design of Ni-base alloys, where grain boundary segregation is expected to play a central role in defining their mechanical behavior. In the present work, we apply a powerful combination of advanced experimental and theoretical methods to reveal the grain boundary chemistry of the 725 Ni-base alloy at the atomic level. The methods of investigation comprise atom probe tomography (APT) measurements and density functional theory (DFT) calculations. We also propose a way to cross-validate DFT and APT results in a DFT-based model approach for evaluation of the interfacial excess as a function of the heat treatment history of the material and its chemistry. Both theoretical and experimental methods are applied to a detailed analysis of the GB chemistry of three modifications of the 725 alloy and the results of this in-vestigation are presented and discussed in detail. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )